ROADMAP: P7 so far, deployed as v1.24.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

.gitea/workflows/deploy.yml

@@ -12,8 +12,7 @@ env:
   BACKUPS: /var/backups/privapub.thepra.dev
   LOCAL_URL: http://127.0.0.1:6970
   PUBLIC_URL: https://privapub.thepra.dev
-  MONGO_URI: mongodb://127.0.0.1:27022
+  SERVER_BACKUPS: /var/lib/privapub/backups
-  MONGO_DB: PrivaPub
 
 jobs:
   site:
@@ -57,12 +56,24 @@ jobs:
           echo "SNAPSHOT=$BACKUPS/site-$STAMP" >> "$GITHUB_ENV"
           ls -1dt "$BACKUPS"/site-* 2>/dev/null | tail -n +4 | xargs -r rm -rf || true
 
-      - name: Dump the database
+      # The server's own backup (PrivaPub admin backup, owner decision 2026-10-07) of the database as the live build left it:
+      # the new build's command runs before its migrations. The media are listed, not linked (the runner may not link
+      # www-data's files; the nightly backups hold them). Never the statistics salt, which must not outlive its day (owner
+      # rule), nor the configuration's copy with its secrets. No deploy while a restore waits for its boot.
+      - name: Back up the database
         run: |
-          DUMP="$BACKUPS/mongo-$(date +%Y%m%d-%H%M%S).archive.gz"
+          [ ! -e "$SERVER_BACKUPS/restore.json" ] || { echo "::error::a restore is pending or running ($SERVER_BACKUPS/restore.json): deploy after it"; exit 1; }
-          mongodump --quiet --uri "$MONGO_URI" --db "$MONGO_DB" --gzip --archive="$DUMP"
+          out=$(cd "$GITHUB_WORKSPACE/publish" && ASPNETCORE_ENVIRONMENT=Production ./PrivaPub admin backup --kind pre-deploy --db-only)
-          echo "::notice::database dumped to $DUMP ($(du -h "$DUMP" | cut -f1))"
+          echo "$out"
-          ls -1t "$BACKUPS"/mongo-*.archive.gz 2>/dev/null | tail -n +8 | xargs -r rm -f || true
+          id=$(echo "$out" | grep -oE '^[0-9]{8}-[0-9]{6}-pre-deploy' | tail -1)
+          [ -d "$SERVER_BACKUPS/$id" ] || { echo "::error::the backup was not made"; exit 1; }
+          (cd "$GITHUB_WORKSPACE/publish" && ASPNETCORE_ENVIRONMENT=Production ./PrivaPub admin backup verify "$id")
+          if [ -e "$SERVER_BACKUPS/$id/db/InteractionSalt.jsonl.gz" ]; then
+            echo "::error::the backup holds the statistics salt"
+            exit 1
+          fi
+          echo "BACKUP_ID=$id" >> "$GITHUB_ENV"
+          echo "::notice::database backed up as $id"
 
       - name: Stop, sync, start
         run: |

.gitignore

@@ -257,6 +257,7 @@ Generated_Code/
 # because we have git ;-)
 _UpgradeReport_Files/
 Backup*/
+!PrivaPub/Infrastructure/Backup/
 UpgradeLog*.XML
 UpgradeLog*.htm
 ServiceFabricBackup/
@@ -401,7 +402,12 @@ FodyWeavers.xsd
 
 PrivaPub/media-store/
 PrivaPub/media-store-proxy/
+PrivaPub/media-store-trash/
+PrivaPub/media-store-incoming/
+PrivaPub/media-store-backups/
 tools/pasture/.publish/
+tools/pasture/.flood/
 .claude/worktrees/
 tools/pasture/.ca/
 tools/pasture/.state/
+tools/pasture/out/

CLAUDE.md

@@ -1,4 +1,4 @@
-# CLAUDE.md
+# CLAUDE.md
 
 Guidance for working in this repository. `docs/ROADMAP.md` holds the owner's decisions and the phased plan to full
 ActivityPub interop; read it before changing anything federation-, privacy- or API-shaped. `docs/INTEROP.md` is the
@@ -21,6 +21,13 @@ Its defining idea: **one private login owns several public personas.**
   becoming two kinds: a public **community** (FEP-1b12, Lemmy-compatible) and a private, invitation-only **circle**.
 - **`DmGroup` is a direct-message conversation.**
 - **`privapub` is the instance actor** (type Application). It signs fetches no persona should be tied to.
+- **`privapub_reports` is the reporter** (type Service, `LocalActorKind.Reporter`). It carries reports to Lemmy, which
+  takes none from an Application, and to PieFed and Mbin, and names nobody.
+- **`privapub_feeds` is the reader of feeds** (type Service, `LocalActorKind.Reader`). When a persona follows a feed
+  (Lemmy's multi-community, PieFed's feed), it follows the feed's communities in the server's name
+  (`Domain/Social/FeedFollows.cs`, owner decision 2026-10-07); its `Following` rows carry `FollowerKind`, and nobody's
+  home gets what it brings in. All three are server actors (`LocalActor.IsServerActor`): never followed, mentioned or
+  shown as accounts.
 
 Privacy features in the model:
 - location-ranged posts (`Post.Location`, `RangeKm`), to become local-only and never federated;
@@ -29,8 +36,8 @@ Privacy features in the model:
 
 The intended client is the Mastodon client API (Tusky, Elk, Phanpy, Ivory), where each avatar logs in as its own
 account. The private `/clientapi` covers what Mastodon can't express. `thepra/decePubClient`
-(https://decepub.thepra.dev) is the owner's own Pleroma-FE-like PWA. It still shows mock data and is not wired to the
+(https://decepub.thepra.dev) is the owner's own Pleroma-FE-like PWA. It signs in once on `/clientapi` and exchanges that
-server.
+JWT for each persona's Mastodon token (`PersonaExchange`), then uses both APIs.
 
 ## Route names are deliberate
 
@@ -83,9 +90,14 @@ PrivaPub/                         ASP.NET Core Web API, net10.0
                                   (authoritative fetch, key verification, WebFinger), ActorDocument (parser)
     Objects/                      Origin, ActivityJson, NoteParser, Addressing, ContentSanitizer
     Moderation/                   DomainBlocks (suspend / silence / reject media)
-    Signing/                      HttpSignatures (draft-cavage sign/verify)
+    Signing/                      HttpSignatures (draft-cavage sign/verify), MessageSignatures (RFC 9421 verify),
+                                  RequestSignature (whichever a request carries), IntegrityProofs (FEP-8b32
+                                  eddsa-jcs-2022 by a persona's Ed25519 key, FEP-521a Multikeys), Jcs (RFC 8785)
     Inbox/                        InboxReceiver (verify, queue, 202) → InboxProcessor (job) → Handlers/{Follow,Accept,Reject,
-                                  Undo,Create,Update,Delete,Like,Announce}; RemotePosts (build, fetch parents, FetchAncestors)
+                                  Undo,Create,Update,Delete,Like,Announce}; RemotePosts (build, fetch parents, FetchAncestors);
+                                  RemoteReplies (FetchReplies: a thread's `context`, else `replies` two levels down);
+                                  Forwarded (what a thread's server passes on, believed as far as the origin vouches);
+                                  ReplyRelay (third-party replies to a persona's posts passed on to its followers)
     Outbox/                       OutboxPublisher (who a post goes to), DeliveryService (queues jobs) + DeliveryJobHandler
     Rendering/                    ActivityPubRenderer (Mastodon @context, actors, notes, collections)
   Domain/
@@ -95,7 +107,9 @@ PrivaPub/                         ASP.NET Core Web API, net10.0
     Privacy/                      VisibilityPolicy (IsPublic expression, CanSee)
     Relationships/                RelationshipService (blocks, mutes, account domain blocks; Hidden), ReportService
     Media/                        MediaService (libvips, ffmpeg remux, blurhash), MediaProxy, MediaJanitor
-  Domain/Statuses/                StatusService: publish, edit, remove, favourite, reblog, for a persona (both client APIs use it)
+  Domain/Statuses/                StatusService: publish, edit, remove, favourite, reblog, for a persona (both client APIs use it);
+                                  InteractionApprovals: GoToSocial's canReply/canLike/canAnnounce, judged, asked and answered;
+                                  Participations: a persona's Join and Leave of a remote event, and the organiser's answer
   Api/Mastodon/
     Auth/                         OpenIddict setup (keys in Mongo), MastodonScopes, TokenController, OAuthPruner
     Infrastructure/               MastodonController (avatar context, scopes, errors, Link), MastodonParams, MastodonJson, Page
@@ -158,16 +172,28 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
    `HttpClient` for federation. The only other outbound traffic is SMTP and `GeoUpdater`'s monthly DB-IP Lite download
    (its own `geo` client, a fixed HTTPS host, size-capped, the file checked before it is swapped in).
 2. **Every fetch is signed by the instance actor** (`privapub`), never by a persona; deliveries are signed by the acting
-   avatar or group. Both are draft-cavage rsa-sha256 over `(request-target) host date` (+ `digest` on bodies).
+   avatar or group. Both are draft-cavage rsa-sha256 over `(request-target) host date` (+ `digest` on bodies). Inbound,
+   an RFC 9421 signature (`Signature-Input`) is verified too, its target against our public address. A persona's own
+   activity going to a relay also carries a FEP-8b32 proof by its Ed25519 key (`Avatar.SigningKey`, one per persona,
+   never shared), and nothing else does: Mitra refuses a proof by a key it has not read. A forwarded activity is taken
+   as it came only when its proof verifies with a Multikey of its actor's.
 3. **A remote document is believed only from its own address.** `RemoteActorService.FetchObject` requires the
    document's `id` to be the URL it was served from (a same-origin alias is followed once). A key is accepted only if
    the actor lists it, its `owner` is the actor and it shares the actor's origin.
 4. **Inbound inboxes verify everything before acting:**
    - the signature covers `(request-target)`, `host`, `digest` and `date` or `(created)`;
    - the Digest matches the body and the date is at most an hour old and fifteen minutes ahead;
-   - the signature verifies against the key owner's key, and the activity's `actor` is the key owner;
+   - the signature verifies against the key owner's key, and the activity's `actor` is the key owner, or else it was
+     forwarded (`Forwarded`: a thread's server passing on what happens in it, as Mastodon and Friendica do). A forwarded
+     activity proves nothing about its author: answered 202, a Create or Update is taken as its object reads at the
+     actor's origin now, a Delete of a public or unlisted copy once that origin answers 404 or 410
+     (`RemoteActorService.IsGone`), anything else let go. Forwarded copies have their own dedupe key, so a copy that
+     failed never hides the author's own delivery;
+   - an activity is queued once per id, but an id that comes back carrying another type, actor or object is a second
+     activity, not a copy (Friendica's ids are `uniqid()`, which two of its processes can share), and is queued apart;
    - the activity's `id`, and any object it creates, updates or deletes, is on the actor's origin; a cross-origin
-     object is refetched from its own origin.
+     object is refetched from its own origin. One attributed to another account of the actor's server (Mobilizon's
+     organiser and the group's event) is taken as that server has it, and deleted once it answers 404 or 410.
 5. **Status codes:**
    - bad or missing signature: **401**;
    - malformed or forged body: **400**;
@@ -195,25 +221,58 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
    when a refetch answers 404, which is why this matters.
    **Communities** are FEP-1b12 groups: `GroupDistributor` announces the whole activity (plus the object for new posts,
    for Mastodon), top-level posts are `Page`s with a `name`, posting follows `Group.PostingPolicy`.
-   Located posts (`LocalGeo`) are the only local-only posts.
+   Located posts (`LocalGeo`) are the only local-only posts. The Mastodon API looks past them everywhere, homes
+   included (the fan-out gives them no `TimelineEntry`, not even their author's): they are read through
+   `/clientapi/post/nearby` and deleted through `/clientapi/post/delete`.
 9. **A DM joins a conversation only by `DmGroup.ParticipantsKey`**, the exact set of its participants; a remote
    `context` decides nothing. DMs are `Post`s with `Visibility = Direct` and a `ConversationId` (`DmPost` is legacy).
+   `DmGroup.LastPostId` pages `/api/v1/conversations`, and `ConversationState` keeps each persona's read and removed
+   marks (`Domain/Statuses/ConversationStates.cs`; writing in a conversation reads it).
 10. **Nothing slow happens inside a request.** Deliveries and inbox processing are `Job`s (`Infrastructure/Jobs`):
     leased, retried on Mastodon's curve, at most two per host, paused per host by `RemoteInstance`. The inbox answers
-    202 once it has verified and queued; a handler must be idempotent (unique `ObjectURI`, job `DedupeKey`).
+    202 once it has verified and queued; a handler must be idempotent (unique `ObjectURI`, job `DedupeKey`). A lease
-11. **Every "may anyone see this" goes through `VisibilityPolicy.IsPublic`;** a persona-specific read uses `CanSee`, and
+    (2 minutes, stamped with its own owner) is renewed every third of its length while the handler runs, so a long job
+    runs once; a lease found taken cancels the handler, and `Finish` only counts for the lease it was given.
+11. **Every number about posts and users goes through `Domain/Privacy/Counted`** (owner decision 2026-10-04: one
+    answer everywhere): a persona's `statuses_count`, its outbox `totalItems`, NodeInfo `localPosts` and the instance
+    `status_count` all count Mastodon's way (not deleted, not a DM, boosts included, circle and located posts too);
+    users exclude personas of banned or deleted roots; `replies_count` counts only public and unlisted replies; a
+    remote account that deletes itself takes its likes, votes, reactions, boosts and replies out of every count
+    (`GoneActors`). Follower and following counts are public, their members never are (`hide_collections` is always
+    true).
+12. **Every "may anyone see this" goes through `VisibilityPolicy.IsPublic`;** a persona-specific read uses `CanSee`, and
     any other read of stored posts filters by `IsShown`. All three hide deleted posts and the posts of a remote account
     that deleted itself (`Post.AuthorGone`: kept, hidden everywhere, owner decision).
-12. **Remote content is stored only when someone here asked for it:** a persona follows the author, is addressed or
+13. **Remote content is stored only when someone here asked for it:** a persona follows the author, is addressed or
     mentioned, it replies to a local post, or it is addressed to a community the author follows; a public parent is
     fetched as context. Followers-only is detected by the author's stored `followers` URL.
-13. **Home timelines are written, not computed:** every stored or created post goes through `Fanout.Distribute`, and
+14. **Home timelines are written, not computed:** every stored or created post goes through `Fanout.Distribute`, and
     every delete removes its `TimelineEntry` rows. Local deletes are soft (content cleared, 410 Tombstone).
+15. **What PrivaPub passes on is exactly what it received** (owner decision 2026-10-05). A public or unlisted reply from
+    another server to a persona's public, unlisted or followers-only post, and its Update and Delete, go to the
+    persona's followers as the activity arrived (`Arrival.Raw`, `Federation/Inbox/ReplyRelay.cs`), signed by the
+    persona for the transport only: never to the replier's own server, never for a local-only or group post. Only an
+    activity its own actor delivered carries `Raw`, so a forwarded one is never passed on again.
+16. **An `Accept` or `Reject` is routed by what it answers:** our Follow (`FollowService`, any `-again-N` resend), an
+    interaction request (`InteractionApprovals`, with the author's authorization read back from its origin) or a
+    persona's `Join` (`Participations`, by its `/grunts/join-<id>` id), each only from the origin of what it answers.
+17. **A server's software is for display, with two exceptions** (owner decisions 2026-10-05 and 2026-10-06): a direct
+    message to one account on a server whose NodeInfo names Lemmy before 1.0 or Mbin goes as a `ChatMessage`
+    (`StatusService.TakesOnlyChatMessages`), as one to an account that writes to us that way does; and a report of a
+    post in a community on a server whose NodeInfo is in `ReportService.ServiceReportTakers` leaves in Lemmy's shape,
+    from the reporter, one `Flag` per post. A server joins that set only once the pasture shows it keeps such a report
+    with its reason. Nothing else may branch on `RemoteInstance.Software`.
 
 ## Mastodon client API invariants
 
 1. **A token is one persona.** Its subject is the avatar id; the root id lives only in the fifteen-minute `/oauth`
    cookie used while choosing the persona, and never in a token, an authorization or a response.
+   - **The first-party client exchanges the root JWT for one persona's token** (RFC 8693 on `/oauth/token`,
+     `subject_token_type` `urn:ietf:params:oauth:token-type:jwt`, `avatar_id`; `Api/Mastodon/Auth/PersonaExchange.cs`).
+     Only the seeded public application (`ClientApi:FirstPartyClientId`, default `decepub`) holds the grant.
+     `RootJwtSubjectToken` validates the JWT through `RootJwt`, the same rules as JwtBearer (signature, lifetime, ban,
+     deletion, session stamp). The issued token is the same kind as the authorization code flow's, so revocation and
+     `RootSessions` cover it.
 2. `/api/*` authenticates with OpenIddict validation, everything else with the old JWT (`PrivaPub` policy scheme).
    Every `/api` request re-checks that the persona's root is neither banned nor deleted (`MastodonController`).
 3. Read parameters through `Params` (query, form and JSON merged Rails-style), never MVC binding. A value type read
@@ -223,9 +282,19 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
    error that leaves without a body (a challenge, a 404 from routing, a 429) gets Mastodon's `{"error": ...}` from
    `UseMastodonErrorBodies`. `NeverFiveHundredTests` walks every route with junk ids, anonymously, as a persona and
    with a junk token.
-6. Advertise `4.2.0 (compatible; PrivaPub)` until grouped notifications exist.
+6. Advertise `4.2.0 (compatible; PrivaPub)` until streaming and Web Push exist too; `api_versions.mastodon = 7` stays,
+   because clients show quotes from it, so everything a 4.3+ client calls because of it must answer: grouped
+   notifications (`/api/v2/notifications`, its unread count, groups, accounts and dismiss) and the notification policy.
+   The policy is real (`Domain/Social/NotificationPolicies.cs`, applied in `Notifications.Add`): accepted by default,
+   it filters (into a `NotificationRequest` per account, out of every list and count unless `include_filtered`) or drops
+   what strangers, accounts that do not follow the persona (or only for three days), accounts newer than 30 days,
+   unasked private mentions and silenced accounts send; accepting a request lets that account in for good
+   (`NotificationPermission`).
 7. **What a Mastodon `Status` cannot say goes in `Status.privapub`** (`PrivaPubStatus`): object type, title, excerpt,
-   cover, the author's source, link, video, audio and event details, and up/down votes. Every media URL in it goes
+   cover, the author's source, link, video, audio and event details, a remote post's own place (Pixelfed's `location`,
+   never federated again), up/down votes and the viewer's own downvote (`votes.downvoted`, set through PrivaPub's
+   `POST /api/v1/statuses/:id/downvote` and `/undownvote`; a favourite is the upvote), and its community's flairs
+   (`ObjectShapes.Flairs`, both dialects). Every media URL in it goes
    through the proxy; only page links (`link.url`, an event's online link) point at the remote site, because following
    one is the reader's choice.
 
@@ -233,18 +302,72 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
 
 1. **No upload keeps its metadata.** Images are re-encoded by libvips with `keep=none`; audio and video are remuxed with
    `-map_metadata -1`. `MediaProcessingTests` checks EXIF and XMP are gone.
-2. Files live under `Media:Root` (`/var/lib/privapub/media`), never in the published directory; the proxy cache is the
+2. **An image is checked before it is decoded.**
-   sibling `media-proxy`, which `/media/files` does not serve.
+   - **Loaders:** only libvips' JPEG, PNG, GIF, WebP and HEIF loaders ever run on an upload (`MediaService`'s static
-3. **A client never contacts a remote server for media:** every remote URL the API returns goes through
+     constructor blocks every other loader), so an SVG, PDF or TIFF claiming another type never loads.
+   - **Size:** the header alone tells width × height (× frames for a GIF), refused above `Media:MaxPixels` (40 MP) or
+     `Media:MaxFrames`.
+   - **Then:** the image is shrunk on load to `MaxImageSide`, turned by its orientation, and its colours brought into
+     sRGB (`thumbnail`).
+   - **GIFs:** an animated GIF becomes a looping silent H.264 mp4 typed `gifv`, as on Mastodon (ffmpeg with libx264;
+     `PostMedia.Kind` says so), and a still GIF is an image.
+   - **Types:** HEIC and HEIF are not accepted, since the bundled libvips has no HEVC decoder.
+   - **Load:** processing runs `Media:Concurrency` at a time, and uploads have their own rate limit (`uploads`, per
+     credential).
+3. **Audio and video are processed off the request when the client allows it.**
+   - **v2:** `POST /api/v2/media` stores them as sent in `media-incoming` (beside the root, never served) and answers
+     202 with no url, while a `ProcessMedia` job (one at a time, its lease renewed) does the work. Until then
+     `GET /api/v1/media/:id` answers 206, and 422 with the reason if it failed. Media still processing can't be posted.
+   - **v1:** processes before answering.
+   - **ffmpeg** reads only the stored file: `-protocol_whitelist file`, and the input format is forced from the probe.
+     Data and subtitle tracks are dropped (`-dn -sn`, which iPhone MOVs need).
+   - **Remux or transcode:** a video browsers play as it is (H.264, VP8, VP9 or AV1, within `Media:MaxVideoPixels` and
+     `MaxFrameRate`) is remuxed; anything else is transcoded to H.264 that fits, as Mastodon does.
+   - **Limits:** longer than `Media:MaxSeconds` is refused.
+   - **Saving:** nothing is saved until everything succeeded; outputs move into place rather than being read into
+     memory, and every temporary file goes. FLAC is served as `audio/flac`, and the unit runs with `PrivateTmp`.
+4. Files live under `Media:Root` (`/var/lib/privapub/media`), never in the published directory; the proxy cache is the
+   sibling `media-proxy` and the trash the sibling `media-trash`, neither of which `/media/files` serves.
+5. **A file lives exactly as long as something holds it.** Every upload is a `MediaAttachment` row, profile pictures
+   too (`Kind` avatar or header, `ProfileOfAvatarId`). Deleting a post, an edit leaving media out, a replaced picture,
+   a dropped scheduled post, a removed root, and an upload never posted for a day each trash theirs
+   (`IMediaService.Trash`):
+   - the row gets `TrashedAt` in one conditional update, so a row attached meanwhile is left alone;
+   - its files move into `media-trash` at once, so `/media/files` stops serving them;
+   - `MediaJanitor` deletes them a day later (`TrashGrace`).
+
+   What a login's media take (every persona's, trashed ones no longer) is `Counted.MediaOfRoot`, shown to the login at
+   `/clientapi/user/storage`; `Media:QuotaBytesPerRoot` (0, none, by default) refuses an upload over it with 422; the
+   administrator's statistics overview has the totals, the proxy cache and the trash.
+
+   Nothing is deleted because it looks unused. `PrivaPub admin media audit [--fix]` compares disk and database: with
+   `--fix` (as www-data) it gives pictures shown from before their rows a row, and trashes media of deleted posts or
+   personas, rows whose files are missing, and files nothing holds.
+6. **A client never contacts a remote server for media:** every remote URL the API returns goes through
    `IMediaProxy.Wrap`, an HMAC-signed `/media/proxy/` URL fetched by `IFederationHttp.GetMedia`.
-4. **The proxy serves three ways:**
+7. **The proxy serves three ways:**
-   - **Cached:** a file already cached is served from disk, ranges included.
+   - **Cached:** a file already cached is served from disk, ranges included. It is opened before the answer, so a trim
-   - **Downloaded:** a request without a `Range` is downloaded whole, up to `Media:MaxProxiedBytes`, then cached.
+     that deletes it meanwhile breaks nothing.
+   - **Downloaded:** a request without a `Range` is downloaded whole, up to `Media:MaxProxiedBytes`, then cached:
+     - once for everyone asking for it at the same time;
+     - streamed into a `.part` file beside its place and renamed there, never held in memory;
+     - with its host in its `.type` sidecar, so that blocking a server can purge it.
    - **Streamed:** a ranged request, or anything too big to cache, is streamed from the origin with the range passed on,
-     and never cached. That is how remote video plays.
+     and never cached. That is how remote video plays. A file found too big is remembered for an hour, so it isn't
+     fetched twice; one that failed is remembered for five minutes.
+
+   Also:
+   - The cache's size is counted as it grows and trimmed as soon as it passes `ProxyCacheBytes`; the janitor
+     recounts hourly.
+   - Browsers may cache only a success.
+   - Nothing of a suspended server, or of one whose media are rejected, is proxied (avatars, emoji, covers and link
+     cards included, since they all go through it), and blocking one purges its cache.
+   - The `proxy` rate limit counts per client address.
 
    nginx has a `/media/proxy/` location with `proxy_buffering off` and a 600 s read timeout for those streams.
-5. **Remote video and audio become one playable attachment** in the Mastodon API (`MastodonMapper.Playable`): the best MP4
+8. **A focal point is two finite numbers** within -1..1 (`FocalPoint.Parse`); anything else is ignored. A stored NaN made
+   every status, timeline and Note holding its post fail to serialise; migration `_016` removed the ones stored before.
+9. **Remote video and audio become one playable attachment** in the Mastodon API (`MastodonMapper.Playable`): the best MP4
    up to 720p that carries both sound and picture, including PeerTube's fragmented files inside an HLS entry. HLS
    playlists themselves are not rewritten.
 
@@ -256,8 +379,8 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   gets "That username and password do not match." after the same hashing (`RootUsersService.Decoy`, a constant-time
   comparison), and only a correct password learns of a ban. Every recovery request answers the same sentence and
   queues a `SendRecovery` job, found or not; `RecoveryJob` sends the email and keeps only a SHA-256 of the code, for an
-  hour. A recovered password ends every session of the root (`RootSessions`: `CredentialsChangedAt` for `/clientapi`
+  hour. A recovered password ends every session of the root (`RootSessions`: a new `SessionStamp`, which every `/clientapi`
-  JWTs, OpenIddict revocation for each persona).
+  JWT carries, and OpenIddict revocation for each persona).
 - **Deleting a root deletes everything public it had** (`RootRemoval`, from the admin route or `/clientapi/user/delete`
   with the password): its sessions end, each persona and each group it owns sends `Delete{Actor}` to followers, members
   and the accounts it follows, the personas' posts are emptied, and `/peasants/{name}`, its inbox and WebFinger answer
@@ -273,7 +396,8 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   see ids. Never emit `CreatedAt`.
 - **Per-avatar state stays per avatar:** blocks, mutes, notifications, follows. Nothing may relate sibling avatars.
 - **Blocks federate** (owner decision, 2026-10-01): a block is sent as `Block` from the blocking avatar, an unblock as
-  `Undo{Block}`. Reports still leave as `Flag` from the instance actor, never from the reporting avatar.
+  `Undo{Block}`. Reports still leave as `Flag` from the server's own actors (the instance actor, or the reporter for
+  communities on Lemmy, PieFed and Mbin), never from the reporting avatar.
 - **What PrivaPub reveals is the owner's call.** Previews, blocks, website authorship, views, bridging and reactions were
   decided in `docs/ROADMAP.md` ("Owner decisions on what PrivaPub reveals"). Anything new that tells another server
   something about an avatar gets the same treatment: ask, then record it there.
@@ -304,7 +428,19 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   revision. Delivery details reach them through `Arrival.Current`, which `InboxProcessor` sets for the handler's
   duration. A fetched record has no signature, key or `@context` of the activity that caused the fetch (its activity
   fields name that trigger), and every record stores its `Extensions` and `ContextNamespaces` for statistics. The raw form lives outside `Post` so timelines never load it. Read through
-  `/api/privapub/v1/statuses/:id/provenance` and `/api/privapub/v1/instances/:host`.
+  `/api/privapub/v1/statuses/:id/provenance` and `/api/privapub/v1/instances/:host` (or `?host[]=`, up to 40; this
+  server answers too).
+- **A server's place leaves only through `PublicGeo.Project`:** the city, coordinates (0.1°) and network it was located
+  to, whatever its size (there is no user threshold), and only the CDN's name for a CDN-fronted one. This server's own
+  place is its host's address located once a day (`SelfLocation`), or `Statistics:Geo:Self` when the owner sets it.
+- **CDNs are found three ways, best first** (`Infrastructure/Geo/CdnCatalog.cs`): the ranges a CDN publishes
+  (`CdnUpdater` downloads them daily into `CdnRangeSet`, keeping the old set when a download or parse fails), the CDN's
+  fingerprint in the responses PrivaPub already gets (`EdgeHintsHandler` on the federation client, memory only), and
+  a network that carries nothing but a CDN. Never list an ASN shared with plain hosting (AWS, Google, Microsoft,
+  DataPacket). A server's `Geo` records the CDN, its domain and how it was found.
+- **Servers through time** (`Domain/Statistics/ServerPlaces.cs`, from the weekly `RemoteInstanceSnapshot`s):
+  `/api/privapub/v1/instances/:host/history`, a CDN-fronted server's `geo.before_cdn`, and the CDNs grouped by their
+  own domain (`/api/privapub/v1/cdns`, `/cdns/:domain` with weekly joined/left).
 - **Remote objects are parsed for every shape in `ObjectShapes`:** `url`/`icon`/`image` as a value, an object or an
   array; Markdown `content`; missing `mediaType`s inferred; thumbnails from any of their five places; and the typed
   `Link`, `Video`, `Audio` and `Event` details. A Mastodon API card is built from those, never by fetching the linked page
@@ -334,7 +470,8 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   same rule writes `canQuote`, answers `QuoteRequest`s (`QuoteService.ReceiveRequest`) and fills `quote_approval`, so they
   cannot disagree. A persona quoting another persona gets a parrot-licence too, so other servers see an approved quote.
 - **A server is described on arrival, never on read.** The first record from a host enqueues `DescribeInstance` (its
-  NodeInfo, at most once a week, into `RemoteInstance`), so opening the details view tells nobody anything.
+  NodeInfo, at most once a week, into `RemoteInstance`), so opening the details view tells nobody anything. A
+  description that failed frees its week, so the server's next arrival (an hour on at the soonest) asks again.
 - **Post ids are the timeline order, so they follow arrival, not `published`.** `PrivacyIds.Arrived` gives a remote post
   published within the last hour (or in the future) a fresh `ObjectId`, which sorts after every post already stored,
   and only backfill keeps a `published`-derived id. With `published` ids a reply arriving in the same second could sort
@@ -349,7 +486,89 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   `_NNN_` order, each runs once), then `Indexes.Create()`. A new entity needs nothing; a new unique index needs a
   dedupe migration before it.
 - Production runs its **own mongod** on 127.0.0.1:27022 (unit `privapub-mongod`, no auth, data in
-  `/var/lib/privapub/mongo`). The box's shared mongod needs credentials nobody here has.
+  `/var/lib/privapub/mongo`). The box's shared mongod needs credentials nobody here has. It is a one-member replica set
+  (`--replSet rs0`, a 990 MB oplog; owner decision 2026-10-07), so a backup reads every collection at one instant;
+  `setup.sh` converts it once (PrivaPub stopped, mongod restarted, `rs.initiate`), and every connection string says
+  `directConnection=true`, which also works against a standalone. The pasture's mongo is one too.
+- **Backups** (`Infrastructure/Backup/`; owner decisions 2026-10-07: the whole server, plain files protected by their
+  permissions, run from the CLI, nightly and from the administrator's page). Each backup is a directory
+  `<yyyyMMdd-HHmmss>-<kind>` under `Backups:Root` (`/var/lib/privapub/backups`, www-data 2770, files 0640), written as
+  `.partial` and renamed once whole:
+  - `manifest.json` (`ArchiveManifest`): host, build, newest migration, whether it was read at one instant, each
+    collection's count, size, sha256 and indexes, what was left out and why, and the media list;
+  - `db/<collection>.jsonl.gz`: each document as one line of canonical Extended JSON, read raw, so every BSON type comes
+    back byte for byte; on a replica set every collection is read in one snapshot session
+    (`minSnapshotHistoryWindowInSeconds` is raised to an hour only while it reads);
+  - `media/`: hard links to the files of untrashed `MediaAttachment` rows (no disk spent; a deleted file stays until the
+    backup rotates out), copies where a link can't be made. `--db-only` lists them instead.
+
+  **Never in a backup** (`ServerBackup.Excluded`): `InteractionSalt` (owner rule), `Job` and `Delivery` (work in flight),
+  `EmailRecovery`, `openiddict.tokens` and `.authorizations` (sessions), `MaintenanceLock`, and `AppConfiguration`
+  (its SMTP password; it is made again from appsettings at boot). One backup or restore runs at a time
+  (`MaintenanceLock`, a heartbeat document; a holder silent for 2 minutes is taken over), and the media janitor purges
+  nothing meanwhile. `BackupScheduler` backs up at `Backups:NightlyAt` (03:30 UTC), or at once when it missed the night;
+  rotation keeps 7 daily and 4 weekly nightly backups, 3 pre-deploy, 3 pre-restore, and manual and uploaded ones until
+  deleted. CLI: `PrivaPub admin backup [--kind manual|pre-deploy] [--db-only]`, `admin backups`, `admin backup verify
+  <id>`; these run before migrations, so the deploy's backup is of the database as the live build left it.
+- **Restores** (`ServerRestore`, `ProtectiveMerge`; owner decision 2026-10-07). Asking (`PrivaPub admin restore <id>`, or
+  the administrator's page) checks the backup (same host, a format and newest migration this build reads, every hash)
+  and writes `restore.json` in the backups' root; the running service sees it within seconds (`RestoreWatcher`) and
+  stops, and systemd starts it again. `MaintenanceGate` (in `Program`, right after the build, before migrations, indexes
+  and hosted services) carries it out:
+  1. a pre-restore backup P, taken once (a retry reuses it, never a half-restored database);
+  2. every collection the backup holds dropped and imported raw with its indexes, every other one dropped, except what a
+     backup never holds, which stays as it is;
+  3. media files the live directory lacks linked back from the backup (or moved from the trash); a restore deletes no file;
+  4. **the protective merge from P: a restore never undoes a protective act.** Followers and follows are P's; blocks,
+     mutes, domain blocks, being blocked, reserved names, `DeletedObject`, reports, filters and OAuth applications are
+     the union, P's row winning; roots, personas, groups, posts and remote accounts deleted since are deleted again, with
+     what their deletion takes away; P's moderation of a persona and a root's password, e-mail, ban and policies stay;
+     roots, personas and groups made since become tombstones (deleted, names kept), local posts made since answer 410,
+     media made or trashed since go to the trash;
+  5. every session ends (a new `SessionStamp` for each root, persona tokens deleted), circuits close, and a
+     `RestoreRecord` (never in a backup) tells what happened (`admin restore --status`).
+
+  Each attempt redoes everything. Refused before anything changed, it is abandoned and recorded, and the server boots as
+  it was; failed midway, the process exits 1 and the next start tries again; after 3 failures it exits 75, which the
+  unit's `RestartPreventExitStatus` leaves down for someone to look. While `restore.json` exists, commands exit 75 (but
+  `admin restore --status`) and the deploy refuses to run. For `RestoreRecord.FollowersGrace` (14 days) after a restore,
+  FEP-8fcf rests: no `Collection-Synchronization` header goes out, and a follow only the remote remembers is adopted,
+  not undone.
+- **The administrator's page** (`BackupController`, `/clientapi/admin/backups`; owner decision 2026-10-07, which approved
+  these endpoints in production): the list (with what runs, the restore waiting, the last restore's report, logins
+  deleted since each backup), back up now (202; the page polls), delete, and:
+  - **download** for the password: a ticket good for ten minutes in the link's path (`/download/{ticket}`, anonymous, so a
+    browser saves it to disk), the backup as one tar (`BackupTar`: its exact length known first, written from the
+    files, `Range` honoured);
+  - **upload** in pieces of at most 32 MB (`TransferStore`): each `PUT ?offset=` must start where the upload stands, else
+    409 with what was received, so a broken upload resumes; `finish` reads it into a backup (`kind` uploaded), refusing
+    anything but plain files under one backup's folder, a path leaving it, or more than the disk holds;
+  - **restore** for the password and the server's host typed out.
+
+  Every call checks the administrator against the database, not only the token. nginx streams downloads for an hour and
+  takes upload pieces unbuffered (`deploy/nginx`, applied by `setup.sh`).
+- **A persona's archive** (`Domain/Portability/`, `PersonaArchiveController` at `/clientapi/persona/{avatarId}/archive`;
+  owner decision 2026-10-07), for the persona's own root only, never a banned one. State per persona in `PersonaArchive`
+  (never in a backup), files in `<backups>/.personas/<avatarId>/`, a week.
+  - **Export** (`ExportArchiveJob`): Mastodon's account-archive layout, so other servers' importers read it: `actor.json`
+    (its public key only), `outbox.json` (its own posts as Creates, addressed as delivered, but circles' and located
+    posts; its boosts as Announces), `media_attachments/files/` (what the attachments' urls name), avatar and header,
+    `likes.json`, `bookmarks.json` and Mastodon's CSV files; then `privapub/`: filters, followed hashtags, the
+    notification policy, pins, scheduled and located posts, `archive.json`. Nothing of its root, its siblings, its keys,
+    anyone's token. Downloaded through a ten-minute ticket in the link's path.
+  - **Import** (`ImportArchiveJob`, the parts the root picks, with progress, stoppable): uploaded in pieces like a backup,
+    read through `SafeArchive`, which refuses links, paths leaving it, names twice, too many or too large files, a file
+    compressed over 100:1, and streams the outbox an item at a time (none over 1 MB). Only the archive actor's own
+    Creates become posts; boosts, direct and circle posts are counted. **Imported posts are delivered to no one**, put in
+    no home and notify nobody (an exception next to located posts), yet show on the profile, the outbox, hashtags and
+    search. Back home (same actor) a post keeps its id and address, and one already here, even deleted, or tombstoned,
+    stays as it is; from another actor it gets an id of its date, its address here and `ImportedFromURI` (unique per
+    persona), so importing twice changes nothing. Replies and self-quotes inside the archive point at their copies; polls
+    come closed without votes; mentions stay links; HTML is sanitized; media go through `MediaService` and the quota.
+    The other parts go through the existing services: follows asked again (never on a blocked server), blocks, mutes,
+    blocked servers, lists (members only if followed), bookmarks (by signed fetch), filters, followed hashtags, the
+    notification policy, pins (no `Add` delivered), the profile (announced as Settings would). Located and scheduled
+    posts (PrivaPub's archives) and likes (each tells its author) only when asked. Followers are never imported.
 
 ## Code style
 
@@ -374,6 +593,8 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
 `PrivaPub.Tests` (xUnit v3). Unit tests need nothing; tests marked `Category=Integration` need a mongod and skip
 without `PRIVAPUB_TEST_MONGOD=1`. CI (`build.yml` and `deploy.yml`) runs all of them through
 `tools/ci/with-test-mongod.sh`, which starts a throwaway mongod on a random localhost port and deletes it afterwards.
+Like production's, it is a one-member replica set (`rs0`, reached with `directConnection=true`), so backups' snapshot
+reads are what the tests exercise (`TopologyTests`).
 The box's own mongods are production, so `MongoFixture` refuses port 27022, a data directory under `/var/lib/privapub`,
 and in CI anything but the wrapper's mongod. With `PRIVAPUB_TEST_REQUIRE_MONGOD=1`, which the wrapper sets, a missing
 mongod fails the run instead of silently skipping half the tests.
@@ -409,6 +630,10 @@ tools/pasture/interop.sh [gts mastodon ...]                          # each peer
 tools/pasture/run.sh down                                            # removes every pasture container and volume
 ```
 
+- **A change to what PrivaPub sends** (the `@context`, an actor's properties, an activity's shape, a delivery's headers)
+  is run against every peer's scenario before it is committed, not only the peers it was written for. One reader
+  stricter than the rest fails on it alone: the 2026-10-06 `proof` term passed every peer but Smithereen, whose JSON-LD
+  1.0 reader refused every document carrying it.
 - **Layout:** `lib/pasture.sh` (network, Caddy, Mongo, PrivaPub), `peers/<name>.sh` (`<name>_up`, plus `peers/shared.sh`
   for the Postgres and Redis several peers share), `lib/interop.sh` (`ok`, `ko`, `xf` for a check expected to fail until
   a later phase, `privapub_token <persona>`, `stats_check <host> <software>`), `scenarios/<name>.sh`. Each peer talks to
@@ -431,9 +656,10 @@ tools/pasture/run.sh down                                            # removes e
     delete is checked as a 404 on `/api/v1/statuses/{id}`.
   - It creates its accounts locked, so the scenario approves alice's request through `/api/v1/follow_requests`, which
     also checks our pending (`requested`) state and the manual Accept.
-  - 55 checks: discovery and follows both ways; posts and CW; a reply and its notification; likes and boosts both
+  - 64 checks: discovery and follows both ways; posts and CW; a reply and its notification; likes and boosts both
     ways; DMs both ways and off public timelines; polls both ways; quote policy; link cards; edits and deletes both
-    ways; communities and circles; locked personas; unfollow; block and unblock; statistics.
+    ways; communities and circles; locked personas; interaction policies (a reply and a like asked for and approved
+    through `/api/v1/interaction_requests`, a boost refused); unfollow; block and unblock; statistics.
   - It files a circle post as a direct message and shows it only to the accounts it mentions, so like a DM it is
     checked in the member's `/api/v1/conversations`, never by URI.
 - **Mastodon (4.7.3):** web and sidekiq on the shared Postgres and Redis, `ALLOWED_PRIVATE_ADDRESSES` for the network.
@@ -441,7 +667,8 @@ tools/pasture/run.sh down                                            # removes e
   deliveries are checked through `/api/v1/accounts/:id/statuses` of the sender as Mastodon knows them, or
   `Status.exists?` through `rails runner`. Its actors are numbered (`/ap/users/<id>`), so look URIs up rather than
   build them. Circle posts and a followers-only post survive its signed refetch (`ActivityPub::FetchRemoteStatusService`
-  through `rails runner`). Inbound Block is the one expected failure until P7.
+  through `rails runner`). Its block of a persona, and the unblock that ends the run, are checked through our
+  `blocked_by`; the run starts with that unblock too, since Mastodon rejects every follow from an account it blocks.
 - **Misskey (2026.10.0):** one container on the shared Postgres and Redis. A new Misskey federates with nobody
   (`federation: none`) until `admin/update-meta` says `all`, which `misskey_up` does. Its API is `POST /api/<endpoint>`
   with the token as `i` (`mk` in the scenario); `users/relation` answers a list, `users/notes` leaves replies out unless
@@ -454,7 +681,7 @@ tools/pasture/run.sh down                                            # removes e
   shipped in the release (CAStore, certifi), so the entrypoint appends Caddy's CA there. `pleroma_ctl` passes its
   arguments on unquoted: no value may contain a space. Its Linkify never takes `@user@host.test` for a mention, so the
   scenario addresses alice with Pleroma's `to[]`; its API never reports a remote blocker as `blocked_by`, so the block is
-  read from its `user_relationships`. 44 checks.
+  read from its `user_relationships`. `akkoma_token <user>` signs one of its users in. 45 checks.
 - **Lemmy (1.0.0-beta.2):** the backend alone on the shared Postgres, its admin made by `setup` in the generated
   `config.hjson`. It trusts Caddy's CA through `SSL_CERT_FILE` and reaches the network through
   `DANGER_FEDERATION_ALLOW_LOCAL_IP=1`; 0.19 cannot join (its rustls trusts only its bundled roots). Its API is
@@ -462,7 +689,189 @@ tools/pasture/run.sh down                                            # removes e
   activity at `warn` (`LEMMY_LOG` sets `RUST_LOG`); the reason is in the 400's body. It answers our community's echo of
   its own activity and every bare `Announce{object}` 400 by design, and the echo is still needed (see
   `docs/INTEROP.md`, Lemmy). A new Lemmy never sends what it queued for a server before its send worker for that
-  server started, so the scenario waits for that worker (`lm_worker`) before its first follow. 20 checks; relayed votes and a moderator's removal are expected failures (P7).
+  server started, so the scenario waits for that worker (`lm_worker`) before its first follow, and it sends what it
+  queued every 30 seconds, so a vote or a moderator's act takes up to a minute. Its lock, unlock and unban need a
+  `reason`, or it refuses them and federates nothing. 29 checks, among them a moderator's lock, ban and removal.
+- **PieFed (1.7.17):** dockurr's image of the release, its web app (with PieFed's own cron, `CRON=true`, for its send
+  queue) and a Celery worker on the shared Postgres and Redis (dbs 10 and 11), sharing the `pasture-piefed-media`
+  volume. httpx trusts only certifi's bundle, so the pasture's is mounted over it. `flask init-db` reads its admin
+  (pfuser) from stdin and drops every table it finds, so it runs once, after the web app's migrations ("Starting
+  Gunicorn"). Its API is Lemmy's v3 under `/api/alpha` with a JWT (`pf` in the scenario); `resolve_object` answers a
+  view (`community.community.id`). It sends a community's announces to the Application at a peer's root, assuming
+  `/inbox` when there is none, and keeps serving a thread its moderator removed. `scenarios/piefed.sh`, 29 checks:
+  communities both ways, threads with titles, comments, votes up and down both ways, a community poll and alice's vote,
+  private messages both ways, a moderator's lock, unlock and removal, the unfollow, statistics.
+- **Mbin (1.10.1):** its own image (FrankenPHP serving plain HTTP behind Caddy, `SERVER_NAME=:80`) and a messenger
+  worker (`mbin_worker`, consuming again whenever it stops: once, the shared Postgres restarted under it and Mbin sent
+  nothing for a day), on the shared Postgres and Redis (db 12) with a RabbitMQ of its own (its transports carry AMQP options; it
+  runs as its own user on its own volume, or it cannot read the `.erlang.cookie` it wrote as root). The pasture's bundle
+  is mounted over the system one; its API's rate limits (two threads every six minutes) are raised by a copy of its
+  `rate_limiter.yaml`. Its admin mbuser is made by its console; `peers/mbin_token.py` gets mbuser's OAuth token through
+  the authorization-code flow (login form, consent), since a client-credentials client acts as a bot that may not vote.
+  Mbin names what it makes during a request after the request's host, so every call says `Host: mbin.test`, never
+  the workstation's port. Its access token lasts an hour, and the scenario gets a new one when it has expired. Its API
+  never starts a conversation with an account elsewhere, so mbuser answers in the thread alice began; Mbin addresses
+  that answer to alice's profile page. `scenarios/mbin.sh`, 26 checks: magazines both ways, threads with titles, a Note
+  to a magazine as a microblog post, comments both ways, favourites and upvotes both ways, private messages both ways,
+  a moderator's lock, unlock and removal, the unfollow, statistics.
+- **NodeBB (4.16.1):** the official image on the pasture's Mongo (database `nodebb`), set up once by its automated
+  setup (`SETUP` with `NODEBB_*` variables, admin nbuser) into the `pasture-nodebb-config` volume, trusting the CA
+  through `NODE_EXTRA_CA_CERTS`; its image runs `npm install` at every start. Its API (`/api/v3`) takes a bearer token
+  that `nodebb_settle` writes where NodeBB keeps its tokens. A remote account's uid there is its actor's URL, but its
+  API follows one only when named by its handle; a chat room is made, then written in. `scenarios/nodebb.sh`, 23
+  checks: a category followed and its topic as a titled thread, replies both ways, nbuser following alice, votes both
+  ways, an edit and a deletion, a chat both ways, the unfollow, statistics.
+- **Lemmy 0.19 (0.19.20), as `lemmy19.test`:** what most of the threadiverse runs. Its release trusts only the roots its
+  rustls bundles, so `images/lemmy19` builds the tag with reqwest's `rustls-tls-native-roots` added (about ten minutes
+  the first time) and the pasture's bundle is mounted as the system's. Its config names the database as `uri` (1.0:
+  `connection`) and its API is v3 (`/api/v3`, `sort=New`, `resolve_object` answering views). It takes private messages
+  only as `ChatMessage`, which PrivaPub sends it, a first message too (invariant 17). `scenarios/lemmy19.sh`, 30
+  checks.
+- **Threads (`scenarios/threads.sh`, needs mastodon):** mastouser follows alice, carol answers alice's public post,
+  and opening the thread on Mastodon finds carol's reply through alice's `replies` (the scenario makes Mastodon's copy
+  look ten minutes old: Mastodon reads a thread's replies only five minutes after it first holds the post). 5 checks.
+- **Followers synchronisation (`scenarios/followsync.sh`, needs mastodon):** sent: PrivaPub forgets mastouser's follow
+  of alice (mongo), alice's followers-only post naming mastouser makes Mastodon read her roll-call and drop it; then
+  Mastodon forgets a follow (rails) and alice's next followers-only post makes it send the `Undo` PrivaPub applies.
+  Received: alice and bob follow mastouser; Mastodon forgets alice's follow and mastouser's followers-only post makes
+  PrivaPub end it, then PrivaPub forgets it and the next makes PrivaPub undo it there. Follows are checked in Mastodon's
+  database: its API caches relationships for a day. 15 checks.
+- **Pins (`scenarios/pins.sh`, needs mastodon):** a Mastodon account pins and unpins while alice follows it, alice pins
+  and unpins while it follows her, a fresh account's earlier pin shows once PrivaPub resolves it, and following it brings
+  its earlier posts (its outbox). 9 checks.
+- **Vernissage (1.43.0):** its image on SQLite in the `pasture-vernissage` volume, its queues on the shared Redis's
+  database 0 (it federates nothing without them; every other database is taken), its seeded admin (admin / admin)
+  logged in by the scenario. `scenarios/vernissage.sh`, 19 checks.
+- **BookWyrm (0.9.3):** its image, migrated, on the shared Postgres (database `bookwyrm`) and Redis (databases 14
+  and 15), gunicorn and one Celery worker (federation runs there). It has no client API: bwuser (named
+  `bwuser@bookwyrm.test`, as its signup names users), a book and every status come from its Django shell
+  (`bookwyrm_shell`, `-v 0`). `scenarios/bookwyrm.sh`, 20 checks.
+- **Ghost (6.67) with its ActivityPub service (1.2.14):** Ghost and the service on the shared MySQL (databases `ghost`
+  and `activitypub`, the service's migrations run first), routed by Caddy as Ghost's own proxy does. The owner comes
+  from Ghost's setup API (a password that repeats the site's name is refused), staff device verification is off, and
+  Ghost starts again once so it sets up its publishing webhooks. Calls to the service say `Host: ghost.test`, or it
+  cannot find the site's keys. `scenarios/ghost.sh`, 22 checks.
+- **Owncast (0.3.0):** its image, its data in the `pasture-owncast` volume, federation turned on through its admin
+  API (`owncast_admin`, its default admin / abc123) with the server's address and the actor's name.
+  `scenarios/owncast.sh`, 13 checks.
+- **WriteFreely (0.17.2):** built from its release tarball with `openssl` beside it (`images/writefreely`, it makes
+  each blog's keys with the command), on SQLite in the `pasture-writefreely` volume, which the scenario reads from the
+  host. wfuser and its blog come from its CLI; its API takes a login. `scenarios/writefreely.sh`, 13 checks.
+- **snac2 (2.95):** built from its tag (`images/snac2`, the project publishes no image), its data in the
+  `pasture-snac` volume from `snac init` and `snac adduser`; the password comes from `snac resetpwd` and the token from
+  its login form and a code grant. Its API lags behind what it has taken in, so `scenarios/snac.sh` reads its files
+  (`snac_stored`, `snac_in_timeline`). 27 checks.
+- **Mitra (5.9.1):** its image on the shared Postgres (database `mitra`), as `mitra.test`, with the pasture's bundle as
+  the system's roots; mitrauser comes from its CLI and its token from a password grant. Its search resolves an account
+  elsewhere only without `type`. `scenarios/mitra.sh`, 28 checks.
+- **Relays (`peers/relay.sh` Activity-Relay 2.0.9 as `relay.test`, on the shared Redis's database 13;
+  `peers/aoderelay.sh` aode-relay 0.3.129 as `aoderelay.test`):** `appsettings.Pasture.json` names both in
+  `Federation:Relays`, so PrivaPub subscribes a minute after it starts. `scenarios/relay.sh` has Mastodon subscribe to
+  each in turn, checks that a post of an account nobody here follows reaches the federated timeline (forwarded by one,
+  announced by the other), that alice's public post goes to the relays (and through both to Mastodon: Activity-Relay's
+  forward on its FEP-8b32 proof, after the scenario makes Mastodon read alice's keys anew) and nothing less public, and
+  has Mastodon leave again, so the town sees no relayed posts. 16 checks.
+- **Castopod (1.15.5, `peers/castopod.sh`):** the official image on the shared MySQL (database `castopod`, file cache,
+  `CP_DISABLE_HTTPS`), its database and superadmin (admin@castopod.test) from `spark`, its REST API switched on in the
+  `.env` the image rewrites at each start, `spark fediverse:broadcast` looping in the container. The podcast `@pod` is
+  made and published through its admin pages (`cp_web`, CSRF on each form). `scenarios/castopod.sh`, 15 checks; the
+  episode's sound is made with ffmpeg on the workstation.
+- **Ktistec (3.13.0, `peers/ktistec.sh`):** built from its tag by `images/ktistec` (its own Dockerfile, pinned: a static
+  Crystal server, its assets with node), SQLite in the `pasture-ktistec` volume, the pasture bundle mounted as
+  `/etc/ssl/cert.pem`. The server's name and ktuser come from its setup API (every field required, `summary` too);
+  `ktistec_token` signs in on `/sessions`. `scenarios/ktistec.sh`, 27 checks: its Mastodon API where it has the route,
+  its outbox API (`kn`) for follows, polls (`poll-duration` is seconds from now), edits, deletions and quotes, and a
+  copy of its SQLite database (`kt_sql`) for what it holds.
+- **Forte (26.9.10, `peers/forte.sh`):** built from its tag by `images/forte` (composer on Hubzilla's PHP image, an nginx
+  routing through `index.php?req=`), on the shared MySQL (database `forte`), its `.htconfig.php` written to
+  `.state/forte`, a cron sidecar (`src/Daemon/Run.php Cron`). The pasture bundle is mounted over `library/cacert.pem`,
+  the bundle its curl uses. ftuser (administrator) and ftfriend are made through its PHP (`forte_eval`: `Account::create`,
+  `Channel::create` with the role `social` and `autoperms`, or every connection waits). Connecting from the command line
+  runs the notifier itself (`ft_connect`). `scenarios/forte.sh`.
+- **Hubzilla (11.4.1, `peers/hubzilla.sh`):** the hlhd image (php-fpm and nginx on 8080) on the shared MySQL
+  (database `hubzilla`, its schema loaded from the image), `.htconfig.php` written to `.state/hubzilla` and mounted, a
+  cron sidecar running `Zotlabs/Daemon/Master.php Cron` each minute. Its addons `pubcrawl` (ActivityPub) and `statistics`
+  (NodeInfo) are installed with `util/addons`; hzuser (the hub's administrator) and hzfriend are made through its own PHP
+  (`hz_eval`), as accounts written the way its registration queue would and channels with the role `public` (the older
+  role names grant connections nothing), the ActivityPub app installed as each channel. Its API (`api/z/1.0`) posts and
+  edits with HTTP Basic (email and password); liking and dropping go through its web pages signed in (`hz_web`).
+  `scenarios/hubzilla.sh`, 20 checks and one known gap (G-0010, its unfollow).
+- **Smithereen (1.0.3):** its image on the shared MySQL (database `smithereen`, its schema from the image's commit),
+  with imgproxy and a file server behind Caddy as `smithereen.test` (`/i` and `/s`), trusting the CA through a JDK
+  store with it added (`JAVA_TOOL_OPTIONS`). MySQL takes its stored functions only with
+  `log_bin_trust_function_creators`, and a first start that failed there leaves the database without triggers (drop it
+  and start again). Accounts come from its signup form (opened, with a short description, which its NodeInfo needs) and
+  are renamed in its database; its API is VKontakte's (`/api/method/<name>?v=1.0`), with a password grant for a local
+  application the peer script inserts. `scenarios/smithereen.sh`, 40 checks, walls both ways (alice's profile is
+  told again first, so Smithereen reads her `sm:wall`; `servers.features & 1` says it took PrivaPub for a server with
+  walls). Its scenario texts avoid apostrophes: `p_home_has` puts them inside a Python string.
+- **Load (`load.sh`, needs the `flood` peer):** `flood` (`flood/flood.cs`, published once into `.flood`) answers as
+  twenty fake servers and sends signed activities at a set rate; `load.sh --rate=N --seconds=N` measures the answers,
+  the queue's wait and processing times, its drain, and a persona's home timeline meanwhile, and keeps each run in
+  `out/load/`. `docs/LOAD.md` has the method and the runs.
+- **Account moves (`scenarios/moves.sh`, needs gts):** two fresh GoToSocial accounts made by its admin CLI; alice follows
+  the old one, the new one names it as an alias (`/api/v1/accounts/alias`), the old one moves (`/api/v1/accounts/move`),
+  and PrivaPub shows it `moved` and moves alice's follow to the new one, which (locked by GoToSocial) approves it.
+  8 checks.
+- **Hollo (0.9.19):** Fedify's microblog server on the shared Postgres, set up through its web form (which
+  checks `Origin` against `Host`, so the request names `hollo.test` without the port). It needs a 44-character
+  `SECRET_KEY`, a media directory and a `themeColor`; statuses and votes go as JSON. Town only, no scenario.
+- **PeerTube (8.3.1):** the official image on the shared Postgres and Redis (db 4), configured through `PEERTUBE_*`
+  variables, trusting Caddy's CA through `NODE_EXTRA_CA_CERTS`; `peertube_settle` turns transcoding off (a test video
+  is served as uploaded) and keeps root's token in `.state/peertube.token`. It wants a bare `Host: peertube.test`.
+  Its list of comments held for review (`/api/v1/users/me/videos/comments?isHeldForReview=true`) answers 500 in 8.3.1;
+  the video's owner sees them in the video's threads (`heldForReview`). `scenarios/peertube.sh`, 28 checks.
+- **Pleroma (2.10.2):** `images/pleroma` installs the OTP release, pinned by checksum, as Akkoma's does; it also needs
+  libvips, and `instance gen` asks about deduplicating uploads. Its federation runs on hackney, which trusts only
+  certifi's compiled-in roots, so the entrypoint points `:pleroma, :http, adapter` at the system CA bundle. It answers
+  an inbox POST at once and verifies in a worker (`oban_jobs` shows what it refused and why). Town only, no scenario.
+- **Iceshrimp.NET (2026.1.2-beta):** on the shared Postgres with AuthorizedFetch on and open registrations, trusting
+  Caddy's CA through `SSL_CERT_FILE`. Accounts come from its own `/api/iceshrimp/auth/register` (its login cuts the
+  connection short for a name it does not know), Mastodon API tokens from its OAuth form, which prints the out-of-band
+  code in the page. Its `jobs` table shows what it queued for whom. Town only, no scenario.
+- **Pixelfed (0.14.4):** serversideup's FrankenPHP image on the shared Postgres (database pixelfed) and Redis (dbs 5 and
+  6), with Horizon and the scheduler as sidecars of the same image sharing its storage volume, and Caddy's CA mounted
+  as its system bundle. `pixelfed_settle` makes `caption` nullable (its PostgreSQL migration never runs, so every remote
+  boost failed), creates Passport's keys and restarts the web server so FrankenPHP reads them, numbers the OAuth
+  clients from a million (Passport refuses a token whose user id equals its client's id), and imports its cities.
+  Tokens are personal access tokens made through tinker (`App\Models\User`). Every top-level post needs a picture.
+  `scenarios/pixelfed.sh`, 26 checks; the town's driver and `specs/pixelfed-pair.json`.
+- **WordPress (7.1.2, ActivityPub plugin 9.3.1):** the official image on a shared MySQL 8.4 (`shared_mysql_up`, ready
+  only when it answers over TCP: its first start runs a server without networking), installed and configured by wp-cli,
+  its CA bundle (`wp-includes/certificates/ca-bundle.crt`) given Caddy's root, and WP-Cron run every five seconds by a
+  sidecar (`DISABLE_WP_CRON`), since the plugin federates from it. Its automatic updates are off
+  (`AUTOMATIC_UPDATER_DISABLED`): the sidecar ran one (6 to 7.1.2) whose new CA bundle dropped Caddy's root, and
+  WordPress reached nobody after it. Authors are actors; the REST API takes application passwords.
+  `scenarios/wordpress.sh`, 17 checks.
+- **Friendica (2026.05):** the official image on the shared MySQL (database friendica) and Redis (db 7, for its cache,
+  locks and sessions), installed by its autoinstall, with the image's worker daemon (`cron.sh`) as a sidecar sharing
+  its files. `friendica_settle` repairs what the install leaves: it names the system user (uid 0), or Friendica never
+  makes the system account that signs its fetches; it declares the daemon running (`worker_daemon_mode` in
+  `key-value`), or the web container, which cannot see the sidecar's pid, never wakes it and everything waits for its
+  five-minute cron; it makes the log file and turns logging on. `friendica_user` saves each account through the API
+  with `locked=0` (a number: "true" reads as 0), which makes it a "soapbox" page that takes followers without asking and
+  follows nobody back, and reads its outbox once: a Follow that reaches a user Friendica has not cached yet makes it
+  fetch that user from itself, signed, and checking the signature recurses for about five minutes. Its API takes HTTP
+  Basic (`nick:password`); an edit through it never federates, so the scenario edits in the web editor.
+  `scenarios/friendica.sh`, 25 checks; the town's driver and `specs/friendica-pair.json`.
+- **Mobilizon (5.2.4):** kaihuri's image of the release on a PostGIS of its own (`shared_postgis_up`: it needs the
+  extension), with the pasture's bundle mounted over certifi's and castore's CA files (hackney trusts only those) and
+  the system store, and geocoding pointed at a closed local port. `mobilizon_ctl users.new` makes mzuser (it splits
+  its arguments on spaces); the API is GraphQL (`/api`), signed in by the `login` mutation. An event made through it
+  without options has its comments closed. `scenarios/mobilizon.sh`, 27 checks: a group and its events (dates, place),
+  alice joining an event (Mobilizon's participant row and its Accept) and leaving it, comments both ways, the
+  organiser's edit, closed comments and deletes, a group post, the unfollow.
+- **Gancio (1.28.2):** cisti's image on sqlite in the `pasture-gancio-data` volume, whose `config.json` is written before
+  the first start (without it Gancio waits in its setup wizard), trusting Caddy's CA through `NODE_EXTRA_CA_CERTS`.
+  `gancio users create` makes gcadmin; `gancio settings set enable_resources true` keeps fediverse replies. One
+  Application actor, `relay`, publishes the agenda. Its API takes a token from an OAuth password grant
+  (`/oauth/login`, client_id `self`); an event is a multipart POST (`--form-string` for text starting with `<`).
+  `scenarios/gancio.sh`, 17 checks.
+- **Funkwhale (2.0.11):** the API (gunicorn), a Celery worker with its beat and the front's nginx, sharing the
+  `pasture-funkwhale-data` volume, on the shared Postgres (database funkwhale) and Redis (dbs 8 and 9); Python's requests
+  trusts the pasture's bundle through `REQUESTS_CA_BUNDLE`. `funkwhale-manage fw users create` makes fwuser and an OAuth
+  access token is made in its Django shell. Its API is `/api/v1` and `/api/v2` (uploads); a track is a fresh tone made
+  by ffmpeg in its container, since it skips a file it already has. `scenarios/funkwhale.sh`, 16 checks.
 - **SecureMode:** `PRIVAPUB_ENV="Federation__SecureMode=true" run.sh up …`, as production runs. A check of what an
   unsigned reader sees uses `unserved` and `gone_unsigned` (`lib/interop.sh`), which expect 401 when SecureMode is on and
   404 or 410 when it is off.
@@ -470,6 +879,45 @@ tools/pasture/run.sh down                                            # removes e
   run.sh up mastodon`, then `interop.sh crawler`. `PRIVAPUB_ENV` passes any setting to the PrivaPub container.
 - `run.sh up` replaces every container, Mongo included, so each run starts clean. To keep the data, republish into
   `tools/pasture/.publish` and `podman restart pasture-privapub`; that is how a migration is tried on dirty data.
+- `run.sh add <peer>` starts more peers next to a running pasture; `run.sh down` removes every pasture container with
+  its volumes (`--purge` drops Caddy's CA too); `run.sh stats` shows each container's memory.
+- **The network looks public** (`PASTURE_SUBNET`, default `11.42.0.0/24`), so peers that refuse private addresses with no
+  switch (Pixelfed, Mbin, WordPress, Discourse, Fedify) federate. Mastodon then needs `TRUSTED_PROXY_IP` for Caddy, or it
+  answers every request with an IP spoofing error.
+- **`PASTURE_PORT`** moves PrivaPub's workstation port off 6971 when something else holds it; `lib/interop.sh` follows.
+- Every `ok`/`ko`/`xf` is also a line of `out/scenarios.jsonl`, which the town's report shows.
+
+#### The town (`tools/pasture/town.sh`, `tools/pasture/town/`)
+
+A fake community seeded across every running peer, then checked for coherence: what each server holds (read from its
+database, never by making it fetch), what each account sees through its API, counts, threads, edits, deletes, follows
+and the privacy rows. Python 3 standard library only, tabs.
+
+```bash
+tools/pasture/town.sh selftest [peer...]   # each driver against its own server; run after changing a driver or a pin
+tools/pasture/town.sh seed village         # specs/village.json: 23 accounts on seven servers, about 11 minutes
+tools/pasture/town.sh check village        # out/<run>/results.json; --deadline=0 re-sweeps an old run at once
+tools/pasture/town.sh report village       # out/<run>/report.html, publishable (fake data, no tokens)
+tools/pasture/town.sh report village hollo-pair iceshrimp-pair pleroma-pair pixelfed-pair friendica-pair   # one matrix
+tools/pasture/town.sh backlog --write      # docs/INTEROP-BACKLOG.md
+```
+
+- **Drivers** (`dialects/`): one class per platform on a dialect base (`mastodon_api`, `misskey_api`, `lemmy_api`,
+  `privapub`). `stored()` reads the database (shared Postgres through `psql`, the shared MySQL through `mysql_json`,
+  GoToSocial's sqlite copied out, Mongo);
+  `seen()` asks the API as one account. A driver that cannot do something raises `Unsupported`, and the planner never
+  asks for it (`gen.CAPS`).
+- **The plan** (`gen.py`) is a pure function of the spec and its seed; each run keeps its own `plan.json`, `ledger.jsonl`
+  (what happened, one fact per line) and `results.json`. `seed --resume` redoes only failed steps.
+- **Cells** are `feature|origin|observer|direction` (`in`, `out`, `via`, `control`, `local`). A known gap is a
+  `gaps.json` entry: matching failures are `xfail`, matching passes `xpass` (close the gap).
+- **What the peers do on purpose**, so the checker expects it: Misskey and Sharkey drop a reply whose parent they cannot
+  fetch; Lemmy keeps only community content and private messages; servers send edits and deletes to the post's own
+  audience only; a Misskey heart reaction arrives as a Like.
+- Peers' own limits are lifted for the town: GoToSocial `GTS_ADVANCED_RATE_LIMIT_REQUESTS=0`, Lemmy's
+  `local_site_rate_limit`. Mastodon reserves usernames that contain `mastodon`.
+- decePubClient's e2e tests (`decePubClient/tests/e2e/run.sh`) publish the client with the Pasture environment, serve
+  it as `https://decepub.test` (`peers/decepub.sh`) and write their cells to `out/client.jsonl`.
 
 After the pasture, verify.funfedi.dev and the owner's GoToSocial at social.arasaka.software. **Ask before acting from
 the owner's GoToSocial account.**
@@ -477,7 +925,9 @@ the owner's GoToSocial account.**
 ## Deploy
 
 - **CI/CD:** push to `master` runs `build.yml` (build + tests) on the instance-wide `build` runner. A `v*` tag runs
-  `deploy.yml`: tests, self-contained linux-x64 publish, snapshot and `mongodump` to `/var/backups/privapub.thepra.dev`,
+  `deploy.yml`: tests, self-contained linux-x64 publish, a snapshot of the site to `/var/backups/privapub.thepra.dev`,
+  the server's own pre-deploy backup (`PrivaPub admin backup --kind pre-deploy --db-only`, run from the new build before
+  its migrations, verified, and checked to hold no statistics salt; no deploy while `restore.json` waits),
   stop → rsync → start, a `127.0.0.1:6970/build.json` health loop with rollback, then public checks (actor, NodeInfo,
   Swagger 404, inbox junk 400, unsigned 401) and `tools/smoke/mastodon-api.sh` (app registration, client credentials,
   discovery, instance, public timeline). Then it checks that what production should be running is running:

FEDERATION.md

@@ -8,33 +8,100 @@ PrivaPub is an ActivityPub server written in C#. This document follows
 - [ActivityPub](https://www.w3.org/TR/activitypub/) (server-to-server)
 - [WebFinger](https://webfinger.net/)
 - [HTTP Signatures](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures), `rsa-sha256` / `hs2019` with RSA keys
+  (`hs2019` hashed with SHA-256, or SHA-512 as some sign it; a `SHA-256=` or `SHA-512=` digest)
+- [HTTP Message Signatures](https://www.rfc-editor.org/rfc/rfc9421) (RFC 9421) and Content-Digest (RFC 9530), verified on
+  deliveries and signed fetches: `rsa-v1_5-sha256` and `rsa-pss-sha512` with RSA keys
 - [NodeInfo](https://nodeinfo.diaspora.software/) 2.0 and 2.1
+- Object integrity proofs ([FEP-8b32](https://codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md),
+  `eddsa-jcs-2022`, JSON canonicalised by [RFC 8785](https://www.rfc-editor.org/rfc/rfc8785)) by Ed25519 keys published
+  as Multikeys ([FEP-521a](https://codeberg.org/fediverse/fep/src/branch/main/fep/521a/fep-521a.md)), on what personas
+  send to relays and verified on what is forwarded
 
 ## Tested against
 
-- **GoToSocial 0.22.1, end to end.** It runs in a private network on the workstation (`tools/pasture/`) and is driven
+End to end, in a private network on the workstation (`tools/pasture/`), each peer driven through its own client API
-  through its own client API. Checked both ways:
+and every run starting clean, with signed fetches required (as privapub.thepra.dev runs):
-  - follows, including to a locked account;
+- **GoToSocial 0.22.1**
-  - public posts with a content warning;
+- **Mastodon 4.7.3**
-  - replies with notifications;
+- **Misskey 2026.10**
-  - likes and boosts;
+- **Sharkey 2025.4.7**
-  - direct messages;
+- **Akkoma 3.20.1**
-  - edits and deletes;
+- **Lemmy 1.0.0-beta.2**, and **Lemmy 0.19.20** (built with the platform's roots, so it trusts the pasture's CA)
-  - unfollow.
+- **PeerTube 8.3.1**
-- **Mastodon, Misskey, Lemmy and PeerTube, by unit tests only.** The tests feed the parser documents written in each
+- **Pixelfed 0.14.4**
-  server's shape. No live exchange with any of them has run yet.
+- **WordPress 7.1.2 with ActivityPub 9.3.1**
+- **Friendica 2026.05**
+- **Mobilizon 5.2.4**
+- **Gancio 1.28.2**
+- **Funkwhale 2.0.11**
+- **PieFed 1.7.17**
+- **Mbin 1.10.1**
+- **NodeBB 4.16.1**
+- **Smithereen 1.0.3**
+- **Mitra 5.9.1**
+- **snac2 2.95**
+- **WriteFreely 0.17.2**
+- **Owncast 0.3.0**
+- **Ghost 6.67** with its ActivityPub service 1.2.14
+- **BookWyrm 0.9.3**
+- **Vernissage 1.43.0**
+- **Hubzilla 11.4.1** with its pubcrawl addon
+- **Forte 26.9.10** (portable identities: actors served through `/.well-known/apgateway/did:key:…`)
+- **Castopod 1.15.5** (podcasts as actors, their episodes with the sound)
+- **Ktistec 3.13.0**
+- **Activity-Relay 2.0.9** and **aode-relay 0.3.129**, as relays PrivaPub reads from
+- in the town only (a seeded community checked server by server): **Hollo 0.9.19**, **Iceshrimp.NET 2026.1.2-beta**,
+  **Pleroma 2.10.2**
+
+Checked both ways, where the peer has the feature:
+- follows, locked accounts included;
+- every visibility, content warnings, replies and their notifications;
+- likes, boosts and emoji reactions with their undos;
+- direct messages;
+- polls;
+- quotes;
+- images with alt text;
+- edits with history and deletes;
+- communities and circles;
+- blocks and unfollows.
+
+`docs/INTEROP.md` has each peer's evidence and what is still expected to fail. The platforms not yet in the pasture are
+covered by unit tests written in their documents' shape.
 
 ## Supported FEPs
 
 - [FEP-67ff: FEDERATION.md](https://codeberg.org/fediverse/fep/src/branch/main/fep/67ff/fep-67ff.md)
 - [FEP-f1d5: NodeInfo in Fediverse Software](https://codeberg.org/fediverse/fep/src/branch/main/fep/f1d5/fep-f1d5.md)
-- [FEP-2c59: Discovery of a WebFinger address from an ActivityPub actor](https://codeberg.org/fediverse/fep/src/branch/main/fep/2c59/fep-2c59.md)
+- [FEP-2c59: Discovery of a WebFinger address from an ActivityPub actor](https://codeberg.org/fediverse/fep/src/branch/main/fep/2c59/fep-2c59.md):
+  every actor names its handle, and a peer's `webfinger` on another domain than its actor's host (Mastodon's
+  `LOCAL_DOMAIN`) is the handle shown once that domain's WebFinger points back to the actor; asked again on a rename
+- [FEP-d556: Server-Level Actor Discovery Using WebFinger](https://codeberg.org/fediverse/fep/src/branch/main/fep/d556/fep-d556.md)
+  (WebFinger for the server's origin links its instance actor as `…#Service`) and
+  [FEP-2677: Identifying the Application Actor](https://codeberg.org/fediverse/fep/src/branch/main/fep/2677/fep-2677.md)
+  (`/.well-known/nodeinfo` links it as `…#Application`)
+- [FEP-844e: Capability discovery](https://codeberg.org/fediverse/fep/src/branch/main/fep/844e/fep-844e.md): the instance
+  actor's `implements`, and every other actor's `generator`, name RFC 9421 (verified with RSA keys)
 - [FEP-1b12: Group federation](https://codeberg.org/fediverse/fep/src/branch/main/fep/1b12/fep-1b12.md) (communities; see "Groups")
+- [FEP-044f: Consent-respecting quote posts](https://codeberg.org/fediverse/fep/src/branch/main/fep/044f/fep-044f.md)
+  (`QuoteAuthorization` at `/parrot-licences/{id}`; checked with Mastodon both ways)
+- [FEP-9967: Polls](https://codeberg.org/fediverse/fep/src/branch/main/fep/9967/fep-9967.md)
+- [FEP-c0e0: Emoji reactions](https://codeberg.org/fediverse/fep/src/branch/main/fep/c0e0/fep-c0e0.md) (`EmojiReact`, and Misskey's
+  `Like` with content)
+- [FEP-5feb: Search indexing consent](https://codeberg.org/fediverse/fep/src/branch/main/fep/5feb/fep-5feb.md) (`indexable`)
+- [FEP-521a: Representing actor's public keys](https://codeberg.org/fediverse/fep/src/branch/main/fep/521a/fep-521a.md) and
+  [FEP-8b32: Object Integrity Proofs](https://codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md) (see
+  "Integrity proofs")
+- [FEP-171b: Conversation Containers](https://codeberg.org/fediverse/fep/src/branch/main/fep/171b/fep-171b.md), received:
+  a thread owner's `Add` of someone's `Create`, `Update` or `Delete` to the thread's context is taken as that activity
+  passed on by the owner (on its FEP-8b32 proof, or as its origin has it)
+- [FEP-8fcf: Followers collection synchronization across servers](https://codeberg.org/fediverse/fep/src/branch/main/fep/8fcf/fep-8fcf.md)
+  (sent and honoured; see "Followers synchronisation")
+- [FEP-5624: Per-object reply control policies](https://codeberg.org/fediverse/fep/src/branch/main/fep/5624/fep-5624.md):
+  read (see "Replies its author approves")
 
-Planned (see `docs/ROADMAP.md`, phases P5 to P8, and the per-platform notes in `docs/INTEROP.md`): FEP-044f (quotes),
+Planned (see `docs/ROADMAP.md`, phases P7 and P8, and the per-platform notes in `docs/INTEROP.md`): FEP-9098 (custom
-FEP-9967 (polls), FEP-c0e0 (emoji reactions), FEP-9098 (custom emoji), FEP-7888 and FEP-f228 (threads), FEP-7628 (Move),
+emoji), FEP-7888 and FEP-f228 (threads), FEP-7628 (Move), FEP-8967 (link
-FEP-8fcf (followers synchronisation), FEP-5feb (`indexable`), FEP-8967 (link attachments), FEP-521a and FEP-8b32 (keys
+attachments), FEP-ae0c (relays).
-and integrity proofs), FEP-ae0c (relays).
 
 ## Actors
 
@@ -52,15 +119,26 @@ actor document, a collection, NodeInfo or a delivery relates two avatars of the
 | Activities | `/peasants/{name}/grunts/{id}` |
 | Quote permissions (`QuoteAuthorization`) | `/peasants/{name}/parrot-licences/{id}` |
 | Direct-message context | `/peasants/{name}/whispers/{id}` |
+| A persona's wall (FEP-400e) | `/peasants/{name}/graffiti` |
+| Followers on the asking server (FEP-8fcf) | `/peasants/{name}/groupies/roll-call` |
 | Profile and post pages | `/@{name}`, `/@{name}/{id}` |
 
 The names are the project's own and are stable; resolve actors through WebFinger, not by guessing a path.
 
 - The key is `{actor}#main-key`, RSA 2048, served as SPKI PEM with `owner` set to the actor.
 - `published` on an actor is a whole day, chosen at random up to two weeks before the account was made, so two
-  personas made on the same day do not share a date. `indexable` is `false`.
+  personas made on the same day do not share a date. `indexable` is `false` unless the persona turns it on, and
+  `discoverable` is `true` unless it turns that off (the deploy's own persona, @thepra, is undiscoverable).
 - The instance actor is `/peasants/privapub` (type `Application`). It signs every fetch PrivaPub makes, so no avatar's key
-  is used to read another server's content.
+  is used to read another server's content. It also answers at the server's root (`/`) for a request that asks for
+  ActivityPub, as Lemmy's site actor does: PieFed sends a community's announces to the inbox of the Application at a
+  peer's root, and to `/inbox` when there is none.
+- The reporter is `/peasants/privapub_reports` (type `Service`, "Reports from <host>"), one for the whole server with
+  its own key. It sends the reports Lemmy, PieFed and Mbin take in Lemmy's shape (see **Reports** below) and does
+  nothing else: nobody follows or mentions it, the Mastodon API has no account for it, and it has no page.
+- The reader of feeds is `/peasants/privapub_feeds` (type `Service`, "Feeds read on <host>"), one for the whole server
+  with its own key. When a persona here follows a feed, the reader follows each community in it, and stops following one
+  no feed read here holds any more; no community and no feed learns which persona reads it. It does nothing else.
 
 ## Groups
 
@@ -68,7 +146,8 @@ A group is either a **community** or a **circle**.
 
 - A **community** follows [FEP-1b12](https://codeberg.org/fediverse/fep/src/branch/main/fep/1b12/fep-1b12.md). Posts
   addressed to it (in `to`, `cc` or `audience`) are accepted according to its posting policy (followers, anyone, or
-  moderators only) and the group `Announce`s the whole activity, with `audience` set, to its followers. A new post is
+  moderators only) and the group `Announce`s the whole activity, with `audience` set, to its followers and to the
+  author's own server, whether anyone there follows it or not (Lemmy keeps its user's post pending until then). A new post is
   also announced as an object so Mastodon shows it. Updates and deletes of community content are announced too. A
   top-level post is a `Page` with a `name`. Members are counted at `/flock`; moderators are listed at `/wardens`, which
   the actor's `attributedTo` points to, with `postingRestrictedToMods` as Lemmy expects. A mention of a community posts into it.
@@ -77,9 +156,28 @@ A group is either a **community** or a **circle**.
   names that member in `cc`, so servers that keep only posts naming one of their accounts (Mastodon, GoToSocial) keep
   it; it names no other member. The posts are served only to a signed request from a member, or from the instance actor
   of a member's server, and that copy names the member (or the members on that server); anyone else gets 404. A
-  Mastodon member's replies reach only the people they mention.
+  Mastodon member's replies reach only the people they mention. Its owner lets a request in with an `Accept` of the
+  Follow, and declines one or takes a member from elsewhere out with a `Reject` of it, as Mastodon removes a follower.
 - Announces from **remote** groups (Lemmy communities) are followed through to the activity: the object is fetched
-  from its own origin, never taken from the announce.
+  from its own origin, never taken from the announce. They are taken from a group someone here follows, and also when
+  they relay a vote on one of our posts in a thread of that group (Lemmy sends a vote to the community alone). A post
+  keeps the group its `audience` names, however it arrived.
+- A post in a remote group followed here that the group's own server delivers itself, as its author's `Create` with the
+  group as its `audience` (Mbin sends a magazine's threads that way, with no announce), is kept as if announced: the
+  group's server speaks for posts in it. The same from another server is not.
+- A remote community's **moderation** reaches the posts it holds. A removal (`Announce{Delete}`) is believed at once
+  from a community on the post's own server, which speaks for it (PieFed keeps serving a thread its moderator removed),
+  and from a community elsewhere once the post's origin answers it gone. A lock sent as it is (`Lock`, Mbin) is taken
+  from the post's own server only. A lock (`Announce{Lock}`, or `commentsEnabled: false` on the post) refuses replies,
+  ours included, until `Undo{Lock}`. A ban of a persona (`Announce{Block}` with the community as `target`) shows as
+  `blocked_by` on the community and refuses the persona's posts and replies there until the `Undo`. A post moved to
+  another community (PieFed's `Announce{Move{object: post, origin, target}}`, relayed by the community it leaves) goes
+  there with its thread; a move into a community this server hosts is not taken.
+- **Feeds** (Lemmy 1.0's multi-communities and PieFed's feeds, `type: Feed`) are read as accounts whose following is
+  their communities: the feed's `following` collection, read once a day with its counts, and each community in it read in
+  turn. A persona following a feed is followed through the server (owner decision 2026-10-07): the reader of feeds
+  follows its communities, the feed itself is sent nothing, and the persona reads the feed's threads in a timeline of
+  its own (`GET /api/v1/timelines/feed/:id`; the feeds it reads are `GET /api/v1/feeds`), not in its home.
 
 ## Activities
 
@@ -88,28 +186,95 @@ Received:
 | Activity | Effect |
 |---|---|
 | `Follow` | follows an avatar or community; `Accept` is sent unless the community approves members by hand |
-| `Accept{Follow}`, `Reject{Follow}` | completes or ends a follow an avatar requested |
+| `Accept{Follow}`, `Reject{Follow}` | completes or ends a follow an avatar requested; once a follow holds, the account's latest public posts are read from its outbox's first page (twenty at most, once a day), so its profile is not empty; homes get only what arrives from then on |
+| `Accept{Join}`, `Reject{Join}` | from the event's server: a persona's participation in the event is accepted or refused |
 | `Undo{Follow, Like, Announce}` | reverses it |
-| `Create{Note, Article, Page, Question, Video, Audio, Event, ChatMessage, …}` | stored when a local avatar follows the author, is addressed or mentioned, when it replies to a local post, or when it is addressed to a community the author follows; a public parent is fetched to complete the thread |
+| `Create{Note, Article, Page, Question, Video, Audio, Event, ChatMessage, …}` | stored when a local avatar follows the author, is addressed or mentioned, when it replies to a local post, or when it is addressed to a community the author follows (a persona is addressed by its actor id or by its profile page, as Mbin addresses its private messages); a public parent is fetched to complete the thread |
 | `Update{Note}` | replaces the content; the previous version is kept |
 | `Update{Person}` | refetches the actor |
 | `Like` | counted and notified, on posts the liker could see |
 | `Dislike` | counted as a downvote (Lemmy, PieFed, Mbin, Friendica); `Undo` takes it back |
 | `EmojiReact`, `Like` with an emoji `content` | an emoji reaction (FEP-c0e0; Pleroma, Akkoma, Iceshrimp.NET, Misskey, Sharkey), Unicode or a custom emoji from its `tag`; a `Like` whose content is ❤ stays a favourite; `Undo` takes it back |
-| `Join` | answered with `Ignore`: PrivaPub hosts no events yet (FEP-8a8e) |
+| `Warn` (Lemmy 1.0) | a community moderator's warning about a persona's post there becomes the persona's `moderation_warning` notification, believed from the community's own server or an account its moderators collection lists |
+| `Resolve{Flag}` (Lemmy 1.0) | a report we sent is marked resolved by the server holding what was reported (kept beside our own moderators' resolution) |
+| `Join` | answered with `Ignore`: PrivaPub hosts no events of its own yet (FEP-8a8e) |
 | `Announce` | counted and notified for local posts; shown to followers of the announcer, with the original refetched from its origin |
-| `Delete` | deletes the object, or the actor and its follows; a deleted object id is remembered for 90 days, so a late `Create` cannot bring it back |
+| `Delete` | deletes the object, or the actor and its follows; a deleted object id is remembered for 90 days, so a late `Create` cannot bring it back, though a new post its server publishes under that id after the deletion (Gancio numbers events from the last one kept) is kept |
 | `Flag` | becomes a report for this server's moderators |
+| `Move` | an account moving: believed as Mastodon believes it, when the account sends it about itself and the new account, read again from its server, names it in `alsoKnownAs`. The old account then shows where it went (`moved`), and, as Mastodon does it (owner decision 2026-10-05), the personas following it follow the new one instead (a Follow to its server, an Undo to the old), in the same lists; a mute or a block of the old account carries over |
+| `Add`/`Remove` on the actor's `featured` | the account pins or unpins one of its own posts (fetched from its server when not held); inside a community's announce, the community features a post made in it. Its profile shows them first (`pinned=true`). The collection itself is read with the account's counts, at most once a day. On the account's wall (`sm:wall`), see "Walls". Any other target (a community's moderators) is dropped; one on the account's own server that PrivaPub does not know has its document read again first, at most hourly |
+| `Block` of a persona | the follows between them end, the blocker's posts and notifications are hidden from the persona, nothing of the persona's is addressed to the blocker, and the relationship says `blocked_by`; `Undo{Block}` lifts it |
 
 Sent: `Follow`, `Undo{Follow}`, `Create{Note}`, `Create{Question}` and poll votes, `EmojiReact` and its `Undo`, `Update{Note}`, `Update{Person}`, `Delete{Tombstone}`, `Accept{Follow}`,
-`Reject{Follow}`, `Like`, `Announce` and their `Undo`, `Flag`. A deleted post answers 410 with a `Tombstone`.
+`Reject{Follow}`, `Like`, `Dislike`, `Announce` and their `Undo`, `Flag`, `Join` and `Leave` of a remote event, and the
+replies to a persona's posts passed on to its followers. A deleted post answers 410 with a `Tombstone`.
+
+- **Votes.** A favourite is a `Like`, a downvote a `Dislike`; a persona has one vote a post, and a changed vote is sent
+  as the new vote alone, as Lemmy sends one (an `Undo` of the old one beside it could arrive after it and take the new
+  one away). `Undo` is sent only when the vote is taken back. A vote on a post in a remote community goes to the
+  community, which counts it and passes it on, as Lemmy sends one, and to the post's author only when it lives on
+  another server: one copy a server, since PieFed drops a second copy of an activity it has just seen.
 
 - **Attachments** are `Document`s with `mediaType`, `name` (alt text), `blurhash`, `focalPoint`, `width` and `height`.
   Uploaded files have all metadata removed.
-- **Pinned posts** are the actor's `featured` collection (`/trophies`); `featuredTags` is `/tattoos`.
+- **Threads** (owner decision 2026-10-06). A persona's public or unlisted post outside any group names its `replies`
+  (`…/scribbles/{id}/replies`) and its conversation, `context` (FEP-7888): the root post's `…/scribbles/{id}/context`,
+  which a reply inherits from its parent, ours or another server's. Both list only the public and unlisted posts
+  PrivaPub holds, the context every one under the root (at most 500); followers-only, circle, direct and local-only posts
+  name neither, and their collections answer 404. Mastodon completes a thread from them.
+- **Followers synchronisation** (FEP-8fcf, owner decision 2026-10-06). A persona's delivery addressed to its followers
+  carries a signed `Collection-Synchronization` header: its `followers`, its roll-call (`…/groupies/roll-call`) and the
+  digest (XOR of each id's SHA-256) of its accepted followers on the receiving server only. The roll-call answers a
+  signed request with the persona's followers on the signer's server and nobody else's; unsigned, 401. A server whose
+  view differs mends itself from it, Mastodon both ways (checked live). Mastodon's `Undo{Follow}` for a follow it never
+  knew of has one id per account (`…#follows//undo`); when it comes again after a new follow, it ends that follow too.
+  Honoured the other way: when a delivery's header digests the sender's followers here otherwise than the personas
+  following it, PrivaPub reads the list it names (same origin, signed by the instance actor). A follow the list leaves out
+  ends, but only when the list is the one the digest describes; a request it lists is taken as accepted; a persona it
+  lists that follows nothing there sends `Undo{Follow}`, as Mastodon does.
+- **Walls** (FEP-400e, Smithereen's; owner decision 2026-10-06). A persona's actor names its `wall`
+  (`…/graffiti`, `sm:wall`) and Smithereen's `privacySettings`: its followers may write on it (`wallPosting`), everyone
+  may read it (`wallPostVisibility`). A public post that is not a reply, sent with the wall as its `target` by an account
+  following the persona, is hosted: the persona is notified (as a mention), it reaches the persona's home and its
+  followers' here, and the persona's followers' servers and the author's are told with `Add{Note}` (the wall as the
+  target). Anything else written there is dropped. The persona may delete it (`DELETE /api/v1/statuses/:id`), which
+  sends `Remove{Note}` with the wall as a plain id; Smithereen deletes the post then, as it does when an owner deletes a
+  post on its wall. The wall lists the persona's public posts that start a thread and what was written on it, newest
+  first. An account elsewhere that tells its followers here, with `Add{Note}` on its own wall, of a post written there
+  has it shown to them as on its wall (`privapub.wall` on the status); a `Remove` there takes it away.
+- **Pinned posts** are the actor's `featured` collection (`/trophies`); `featuredTags` is `/tattoos`. A pin or an unpin
+  is told to the post's audience as `Add` or `Remove` on `featured`, as Mastodon tells it.
 - **Blocks are sent.** A blocked remote account receives `Block` from the blocking account (and `Reject{Follow}` if it
   followed); an unblock sends `Undo{Block}`.
-- **Reports** are sent as `Flag` by the instance actor, never by the reporting account.
+- **Reports** are sent as `Flag`, never by the reporting account and never naming it.
+  - To the reported account's server: from the instance actor, with the account and the posts as `object` and the
+    persona's words in `content`.
+  - To a community on a server whose NodeInfo names Lemmy, PieFed or Mbin (owner decision 2026-10-06, the second place
+    PrivaPub decides by a server's software; PieFed and Mbin once the pasture showed each keeps such a report with its
+    reason): one `Flag` per reported post or comment that was made in that community (its own
+    `audience`, else its thread's), from the reporter, `to` the community, the post alone as `object`, the words (or,
+    with none, the category) in `summary` and `content`, sent to the community's inbox. Lemmy refuses a Flag from an
+    `Application`, with no `to` or with no reason; PieFed drops one from an `Application`; Mbin reads the reason from
+    `summary` alone. Such a server gets no instance actor's Flag: an account alone, or a post outside its communities,
+    is not reported there, since Lemmy takes neither (PieFed would take an account alone from the reporter; that is not
+    sent yet).
+- **Direct messages** go out as a `Note` addressed to their recipients, except a message to one account elsewhere that
+  writes to us as `ChatMessage`s (Pleroma's type), or whose server takes nothing else: Lemmy before 1.0 and Mbin, as
+  their NodeInfo names them (owner decision 2026-10-05, the first place PrivaPub decides by a server's software). That
+  message goes out as a `ChatMessage`, to the account alone, without a mention in its text.
+- **Replies are passed on** (inbox forwarding; owner decision 2026-10-05). A public or unlisted reply from another server
+  to a persona's public, unlisted or followers-only post goes on to the persona's followers as its author's server sent
+  and signed it, the way Mastodon forwards it: to every follower's server but the replier's own. Its `Update` and
+  `Delete` follow the same way. Nothing is passed on for a local-only post, a group's post or a reply that is not public
+  or unlisted. A server that receives it checks it as it checks any forwarded activity: Mastodon, Misskey and Sharkey
+  keep it only when its author LD-signed it (Mastodon does; Misskey 2026.10 and Akkoma do not), others read the reply
+  from its origin.
+- **Events** (owner decision 2026-10-05). A persona joins another server's event with a `Join` and leaves it with a
+  `Leave`, both sent to the event's organiser only (`…/grunts/join-<id>`, `…/grunts/leave-<id>`). The organiser's
+  server answers `Accept` (Mobilizon at once for an open event) or `Reject`, which the persona sees as
+  `privapub.event.participation`: `pending`, `accepted` or `rejected`. An event that takes participants by invitation
+  or on another site (Mobilizon's `joinMode` `invite` or `external`) is refused before anything is sent (422). Who
+  takes part is public on the event's server.
 
 A `Create`'s `Note` carries Mastodon's `content`, `contentMap`, `summary` and `sensitive`, plus `Mention` and `Hashtag`
 tags.
@@ -119,6 +284,8 @@ tags.
 content, one per choice, counted once per voter. Counts are refreshed with an `Update{Question}` at most every three
 minutes. Our own votes on other servers' polls are sent the same way to the poll's author only, without `published`.
 An incoming `Update` without a newer `updated` only refreshes counts and details; it is never recorded as an edit.
+A post's earlier versions in `formerRepresentations` (Pleroma, Akkoma) are its edit history, read as the post itself is:
+a post first met after its edits has them, and an edit that carries them brings the versions missed in between.
 
 **Quotes** (FEP-044f, with the older keys):
 - **Received.** A quote is read from `quote`, `quoteUrl`, `quoteUri`, `_misskey_quote` or a FEP-e232 `Link` tag.
@@ -141,6 +308,28 @@ An incoming `Update` without a newer `updated` only refreshes counts and details
     `Delete{stamp}`.
   - Followers-only posts and DMs can never be quoted.
 
+**Interaction policies** (GoToSocial's `canReply`, `canLike`, `canAnnounce`, with the older `always` and
+`approvalRequired`):
+- **Read** on every remote post; one left out means anyone, automatically. A persona is let in at once when the rule
+  names the public, the persona itself, the author's followers while it follows the author, or the accounts the author
+  follows while the author follows it.
+- **Shut out:** the client API answers 422 to a reply, favourite or boost the rule does not allow at all.
+- **Asked first:** a `ReplyRequest`, `LikeRequest` or `AnnounceRequest` (the interaction as its `instrument`) goes to the
+  author alone, and the interaction waits (`privapub.approval: pending`). The author's `Accept` brings an authorization
+  (`result`), which must be on the author's origin, attributed to them and naming the interaction and the post; only then
+  does the reply go out with `replyAuthorization`, the boost with `announceAuthorization` and the like with
+  `likeAuthorization`. A `Reject` leaves it ours alone (`rejected`), and takes a like or a boost back.
+- **As a third party,** a reply that a post's policy does not let in at once is kept only with an authorization that
+  verifies the same way. A rule naming a collection we cannot list (followers, following) lets the reply in.
+- **Shown** to clients as GoToSocial's `interaction_policy` (`can_favourite`, `can_reply`, `can_reblog`).
+- Our own posts state only `canQuote`: anyone may reply to, like and boost them.
+
+**Replies its author approves** (FEP-5624's `canReply`, as PeerTube sets it on a video whose comments are moderated; a
+`null` one says nothing): a persona it names, or that the post mentions, may reply, and the reply waits
+(`privapub.approval: pending`), its `Create` going to the author alone. The author's `ApproveReply`, signed by the author
+and naming the post answered, lets it out to its audience with `replyApproval`; a `RejectReply` leaves it ours alone
+(`rejected`). An empty `canReply` refuses every reply (422).
+
 **Custom emoji** (`Emoji` tags) are read on posts, display names, bios and profile fields, at most 64 per object.
 **Profiles** keep their header, profile fields, `manuallyApprovesFollowers`, `published`, `movedTo`, `indexable`,
 `memorial` and avatar and header descriptions. A post's title becomes `name` and is also the first, bold line of `content`, because Mastodon does not show
@@ -164,6 +353,19 @@ The page's OpenGraph and Twitter tags give the title, description and image; the
 days and shared by every account on the server. Images are served to clients only through PrivaPub's media proxy.
 `Federation:FetchLinkPreviews=false` turns page fetching off.
 
+## Relays
+
+PrivaPub reads from the relays `Federation:Relays` names (by their actor's address, or their inbox's), none by default.
+Its instance actor follows `Public` at each, as Mastodon subscribes (`Federation/Relays/Relays.cs`, a minute after start
+and every six hours: an unanswered or refused subscription is asked again a day later, and a relay no longer named gets
+the `Undo`). What an accepted relay passes on comes to the federated timeline, never to anyone's home: a public post it
+forwards as its author sent it (Activity-Relay), read again from its origin like any forwarded post, and a post it
+announces (aode-relay), kept as its author's and never as the relay's boost. Nothing else is taken from a relay. A
+persona's public post outside any group, its edit and its deletion also go to the relays that accepted us (owner decision
+2026-10-06), as Mastodon sends them; nothing less public, and no boost. Mastodon takes a post Activity-Relay forwards
+only with an LD signature or an FEP-8b32 proof: PrivaPub's carry a proof, so they reach Mastodon through both kinds of
+relay (checked live).
+
 ## Server descriptions and the crawler
 
 PrivaPub keeps statistics about servers, never about accounts (see `/stargazing` on the server).
@@ -192,10 +394,31 @@ Posts with a location (shown to nearby users of this server) never leave the ser
 - **Origins.** An actor document is accepted only from the address it names as its `id`. A key only if its actor lists
   it with `owner` set to the actor and on the actor's origin. An activity's `id`, and any object it creates, updates or
   deletes, must be on its actor's origin. An embedded object from another origin is fetched from that origin.
+- **Another account of the same server.** An object attributed to another account of the actor's own server (Mobilizon's
+  organiser creates, edits and deletes the group's event) is that server's to vouch for: a creation or an edit is
+  taken as the server has the object, a deletion once it answers 404 or 410. Attributed to an account elsewhere, it is
+  refused (400).
+- **Forwarded activities** (ActivityPub's inbox forwarding: a thread's server passing on the replies in it, signed with
+  its own key) are answered 202 and believed only as far as their origin vouches for them: a created or edited post
+  is read again from its author's server, a deletion of a public or unlisted post is applied once that server answers
+  404 or 410, and anything else is dropped. LD signatures are not verified. A reply forwarded this way is kept when
+  someone here follows the author of the post it answers, as Mastodon does.
+- **Follow requests** still unanswered are sent again after 15 minutes, an hour, 6 hours, a day, two and four days: a
+  server can take a Follow and lose its answer (Lemmy 1.0 sends nothing it queued for a server before it started
+  sending there), and one that holds the follow answers it again. Each is the same follow under a new id
+  (`…/follow-<id>-again-<n>`), since Lemmy ignores an id it has seen; an answer naming any of them counts.
 - **Fetching.** All fetches are signed by the instance actor. They go only to public addresses, follow at most three
   redirects and read at most 1 MB.
+- **Threads.** A reply's missing parents are fetched, up to 10 levels. When someone here opens a public remote thread,
+  its replies are read from their servers, at most once an hour: the thread's conversation container (FEP-171b's
+  `contextHistory`: the posts its owner's `Add`s brought in) or its `context` collection (FEP-7888) if it has one, else
+  its `replies` (PeerTube's `comments`) and theirs, two levels down; 5 pages and 100 posts at most. Only public and
+  unlisted replies are kept, each fetched from its own origin. A thread collection read whole, which counts its posts or
+  holds them all, is asked again with `If-None-Match` and its last ETag; a 304 ends the read.
 - **Reading our documents (SecureMode).** privapub.thepra.dev answers ActivityPub GETs only when they are signed, like
-  Mastodon's authorized fetch; the instance actor `/peasants/privapub` is the exception, since its key is needed first.
+  Mastodon's authorized fetch; the server's own actors (the instance actor `/peasants/privapub`, the reporter
+  `/peasants/privapub_reports` and the reader of feeds `/peasants/privapub_feeds`) are the exception, since their keys
+  are needed first.
   A browser asking for HTML is redirected to the public page instead.
 - **Posts that are not public** (followers-only, direct, circle) are served to a signed request from someone they were
   for, or from the instance actor of a server where someone they were for lives, and to nobody else (404). Once deleted
@@ -204,16 +427,38 @@ Posts with a location (shown to nearby users of this server) never leave the ser
 - **HTML.** Received HTML is sanitised to Mastodon's allowlist.
 - **Keys we cannot fetch for now.** When a sender's key cannot be fetched because its server timed out or answered
   5xx, the inbox answers 503 with `Retry-After: 300` rather than 401.
-- **Activity ids.** `Create` and `Announce` ids dereference. `Follow`, `Like`, `Block` and the `Accept`, `Reject` and
+- **Activity ids.** `Create` and `Announce` ids dereference, a community's announces included, until the post they
-  `Undo` that answer them do not, because serving them would reveal who follows, likes and blocks whom; they are always
+  carry is deleted (then 410); a persona's boost id sends a browser to the boosted post. `Follow`, `Like`, `Block` and
-  sent with their object embedded.
+  the `Accept`, `Reject` and `Undo` that answer them do not, because serving them would reveal who follows, likes and
-- **Delivery.** Failed deliveries are retried with Mastodon's backoff (16 attempts). A host that keeps failing is paused,
+  blocks whom. Neither do `Update`, `Delete`, `EmojiReact`, `QuoteRequest` and its answers, `Flag`, `Ignore` or poll
-  starting at an hour and growing to a week.
+  votes. All of them are always sent with their object embedded. Every boost and every favourite is an activity of its
+  own (`announce-{boost}`, `like-{favourite}`), so one given again after its `Undo` is new to the server it reaches.
+- **Hashtags.** A post's `Hashtag` links go to `/tags/{tag}`, a public page of this server's public posts with that tag.
+- **Delivery.** An activity goes once to each server, to its shared inbox when the server has one, whoever there it
+  follows, names or answers (a circle post excepted: each member's copy names that member). Failed deliveries are
+  retried with Mastodon's backoff (16 attempts). A host that keeps failing is paused,
+  starting at an hour and growing to a week: unreachable, timing out, or a gateway answering 502, 503 or 504. A 500 is
+  the server failing on that one activity, retried on its own while its other deliveries go on. A server can also take a Follow (202) and drop it afterwards, as Pleroma
+  does when it cannot yet fetch our actor, so a follow request still unanswered is sent again, same activity, when the
+  persona follows once more, at most once an hour.
 
 ## Known limitations
 
 - Our own posts carry no custom emoji: emoji are received and shown, not offered.
 - Remote media is fetched through this server's proxy when a local client displays it. Video and audio are streamed
   through it with byte ranges passed on, so a PeerTube file is never fetched whole for one viewer.
-- Collections expose counts, not members.
+- Collections expose counts, not members: `/groupies` and `/stalking` give the same totals as the Mastodon API's
-- Only `rsa-sha256`-style keys are verified. RFC 9421 signatures are planned.
+  follower and following counts, and the outbox's `totalItems` is the persona's post count, though only public posts
+  are listed. `/api/v1/instance/peers` is empty: which servers this one talks to is not published.
+- HTTP signatures are verified with RSA keys only, under draft-cavage or RFC 9421. What PrivaPub sends is signed with
+  draft-cavage only, which every server reads.
+- **Integrity proofs** (FEP-8b32, FEP-521a). Every persona has an Ed25519 key of its own (never shared between personas),
+  named in its actor's `assertionMethod` as a `Multikey` (`…#ed25519-key`, `publicKeyMultibase`); the terms are defined
+  in the actor's own context, so no context document has to be fetched. A persona's activity going to a relay carries a
+  `DataIntegrityProof` (`eddsa-jcs-2022`, `proofPurpose` `assertionMethod`) over the activity as delivered; Mastodon
+  4.7 verifies it (checked against its own verifier), so what the relay forwards reaches it. Nothing else carries one:
+  Mitra takes a proof over the HTTP signature, and refuses one by a key it has not read yet without reading the actor
+  again, which every server that knew a persona before it had its key would do. What a persona passes on of others'
+  carries theirs or none. Received: an actor's own Multikeys (at most five, under its id, controlled by it) are kept;
+  a forwarded activity whose proof one of them verifies is taken as it came, instead of being read again from its origin
+  (an unknown key of the actor's has the actor read again first).

PrivaPub.ClientModels/Admin/ViewBackups.cs

@@ -0,0 +1,103 @@
+using PrivaPub.ClientModels.Resources;
+
+using System.ComponentModel.DataAnnotations;
+
+namespace PrivaPub.ClientModels.Admin
+{
+	// the server's backups as the administrator's page shows them, with what is running and the last restore
+	public class ViewBackups
+	{
+		public List<ViewBackup> Backups { get; set; } = [];
+		public string Running { get; set; }//"backup" or "restore" while one runs
+		public ViewRestoreWaiting Waiting { get; set; }
+		public ViewRestore LastRestore { get; set; }
+		public string Host { get; set; }//what a restore asks to be typed
+		public long FreeBytes { get; set; }
+	}
+
+	public class ViewBackup
+	{
+		public string Id { get; set; }
+		public string Kind { get; set; }//nightly, manual, pre-deploy, pre-restore, uploaded
+		public DateTime CreatedAt { get; set; }
+		public long Bytes { get; set; }//the database's files
+		public long MediaBytes { get; set; }
+		public int MediaFiles { get; set; }
+		public int MediaMissing { get; set; }
+		public bool DbOnly { get; set; }
+		public bool Consistent { get; set; }
+		public int Collections { get; set; }
+		public long Documents { get; set; }
+		public string AppCommit { get; set; }
+		public int MigrationNumber { get; set; }
+		public int RootsDeletedSince { get; set; }//logins deleted after it, which a restore deletes again
+		public string NotRestorable { get; set; }//why not, from its manifest; hashes are checked when asked
+	}
+
+	public class ViewRestoreWaiting
+	{
+		public string Backup { get; set; }
+		public string State { get; set; }
+		public int Attempts { get; set; }
+		public string RequestedBy { get; set; }
+		public DateTime RequestedAt { get; set; }
+		public string Error { get; set; }
+	}
+
+	public class ViewRestore
+	{
+		public string Backup { get; set; }
+		public DateTime BackupCreatedAt { get; set; }
+		public string PreRestore { get; set; }
+		public string RequestedBy { get; set; }
+		public DateTime RestoredAt { get; set; }
+		public bool Abandoned { get; set; }
+		public string Error { get; set; }
+		public long Documents { get; set; }
+		public int Collections { get; set; }
+		public int MediaRestored { get; set; }
+		public int MediaMissing { get; set; }
+		public int RootsDeleted { get; set; }
+		public int PersonasDeleted { get; set; }
+		public int GroupsDeleted { get; set; }
+		public int PostsDeleted { get; set; }
+		public List<string> RootsTombstoned { get; set; } = [];
+		public List<string> PersonasTombstoned { get; set; } = [];
+		public List<string> GroupsTombstoned { get; set; } = [];
+		public int PostsGone { get; set; }
+		public int MediaTrashed { get; set; }
+		public int ProtectiveKept { get; set; }
+		public int SessionsEnded { get; set; }
+	}
+
+	// a backup downloaded or restored: the administrator's password again, and for a restore the server's host typed out
+	public class BackupPasswordForm
+	{
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			StringLength(200, ErrorMessageResourceName = "MaxLengthString", ErrorMessageResourceType = typeof(ErrorsResource))]
+		public string Password { get; set; }
+	}
+
+	public class RestoreBackupForm : BackupPasswordForm
+	{
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			StringLength(253, ErrorMessageResourceName = "MaxLengthString", ErrorMessageResourceType = typeof(ErrorsResource))]
+		public string Host { get; set; }
+	}
+
+	// a download link good for a while, for one backup
+	public class ViewBackupTicket
+	{
+		public string Url { get; set; }
+		public DateTime ExpiresAt { get; set; }
+		public long Bytes { get; set; }
+	}
+
+	// a backup being uploaded in pieces: how much has arrived
+	public class ViewBackupUpload
+	{
+		public string Id { get; set; }
+		public long Received { get; set; }
+		public long ChunkBytes { get; set; }//the largest piece accepted
+	}
+}

PrivaPub.ClientModels/Admin/ViewReport.cs

@@ -0,0 +1,22 @@
+namespace PrivaPub.ClientModels.Admin
+{
+	// a report as moderators read it: who sent it ("local" for a persona here, never which one; or the remote actor), whom
+	// and which posts it is about, and whether it was resolved
+	public class ViewReport
+	{
+		public string ID { get; set; }
+		public string Reporter { get; set; }
+		public string TargetAccountId { get; set; }
+		public string TargetActorURI { get; set; }
+		public List<string> PostIds { get; set; } = new();
+		public List<string> ObjectURIs { get; set; } = new();
+		public string Category { get; set; }
+		public string Comment { get; set; }
+		public bool Forwarded { get; set; }
+		public bool IsResolved { get; set; }
+		public DateTime CreatedAt { get; set; }
+		public DateTime? ResolvedAt { get; set; }
+		public DateTime? RemoteResolvedAt { get; set; }//the server holding what was reported said it dealt with it
+		public string RemoteResolvedBy { get; set; }
+	}
+}

PrivaPub.ClientModels/Admin/ViewStatistics.cs

@@ -0,0 +1,99 @@
+namespace PrivaPub.ClientModels.Admin
+{
+	// /clientapi/admin/statistics/overview: the last days' federation at a glance; counters keyed as the ledger keys them
+	public class ViewStatisticsOverview
+	{
+		public int Days { get; set; }
+		public Dictionary<string, long> Channels { get; set; } = new();
+		public Dictionary<string, long> Inbound { get; set; } = new();
+		public Dictionary<string, long> Outbound { get; set; } = new();
+		public double? DeliverySuccess { get; set; }
+		public ViewLatency DeliveryLatencyMs { get; set; } = new();
+		public ViewHostCounts Hosts { get; set; } = new();
+		public int Accounts { get; set; }
+		public ViewLedgerCounts Ledger { get; set; } = new();
+		public ViewMediaTotals Media { get; set; } = new();
+	}
+
+	// what media take on the server: the uploads and pictures kept, the remote media cache, the trash waiting its grace
+	public class ViewMediaTotals
+	{
+		public long MediaBytes { get; set; }
+		public long MediaFiles { get; set; }
+		public long ProxyCacheBytes { get; set; }
+		public long TrashBytes { get; set; }
+	}
+
+	public class ViewLatency
+	{
+		public int? P50 { get; set; }
+		public int? P95 { get; set; }
+	}
+
+	public class ViewHostCounts
+	{
+		public int Active { get; set; }
+		public long Known { get; set; }
+	}
+
+	public class ViewLedgerCounts
+	{
+		public long Written { get; set; }
+		public long Dropped { get; set; }
+		public long Failed { get; set; }
+	}
+
+	// /clientapi/admin/statistics/hosts: one page of the servers we exchanged with
+	public class ViewHostsPage
+	{
+		public int Total { get; set; }
+		public int Page { get; set; }
+		public List<ViewHostRow> Hosts { get; set; } = new();
+		public string Attribution { get; set; }
+	}
+
+	public class ViewHostRow
+	{
+		public string Host { get; set; }
+		public string Software { get; set; }
+		public string Version { get; set; }
+		public long In { get; set; }
+		public long Out { get; set; }
+		public long Refused { get; set; }
+		public long Failures { get; set; }
+		public int? LatencyP50 { get; set; }
+		public int Accounts { get; set; }
+		public DateTime? DescribedAt { get; set; }
+		public ViewHostDelivery Delivery { get; set; }
+	}
+
+	public class ViewHostDelivery
+	{
+		public int ConsecutiveFailures { get; set; }
+		public DateTime? UnavailableUntil { get; set; }
+		public DateTime? LastSuccessAt { get; set; }
+		public DateTime? LastFailureAt { get; set; }
+	}
+
+	// /clientapi/admin/statistics/crawler: how far the crawler got
+	public class ViewCrawler
+	{
+		public bool Enabled { get; set; }
+		public long Touched { get; set; }
+		public long Crawled { get; set; }
+		public long Due { get; set; }
+		public long RobotsDisallowed { get; set; }
+		public List<ViewCrawledHost> Recent { get; set; } = new();
+	}
+
+	public class ViewCrawledHost
+	{
+		public string Host { get; set; }
+		public string Seen { get; set; }
+		public DateTime? LastCrawledAt { get; set; }
+		public int? PeersCount { get; set; }
+		public bool? RobotsDisallowed { get; set; }
+		public string CrawlError { get; set; }
+		public string Software { get; set; }
+	}
+}

PrivaPub.ClientModels/Group/ViewGroupMember.cs

@@ -0,0 +1,15 @@
+namespace PrivaPub.ClientModels.Group
+{
+	// someone in a group, or asking to join it, as its owner and moderators see them
+	public class ViewGroupMember
+	{
+		public string ActorUri { get; set; }
+		public string Handle { get; set; }
+		public string Name { get; set; }
+		public string PictureUrl { get; set; }
+		public bool IsLocal { get; set; }
+		public bool IsPending { get; set; }
+		public string Role { get; set; }//owner, moderator, member
+		public DateTime Since { get; set; }
+	}
+}

PrivaPub.ClientModels/User/ViewPersonaArchive.cs

@@ -0,0 +1,48 @@
+namespace PrivaPub.ClientModels.User
+{
+	// A persona's archive (owner decision 2026-10-07): made for it to take away, in Mastodon's account-archive layout, and
+	// restored into it. States: none, queued, running, ready (export) or done (import), failed, stopped.
+	public class ViewPersonaArchive
+	{
+		public string ExportState { get; set; }
+		public DateTime? ExportAskedAt { get; set; }
+		public DateTime? ExportReadyAt { get; set; }
+		public DateTime? ExportExpiresAt { get; set; }
+		public long ExportBytes { get; set; }
+		public string ExportError { get; set; }
+
+		public string ImportState { get; set; }
+		public DateTime? ImportAskedAt { get; set; }
+		public DateTime? ImportEndedAt { get; set; }
+		public List<string> ImportParts { get; set; } = [];
+		public long ImportDone { get; set; }
+		public long ImportTotal { get; set; }
+		public Dictionary<string, int> ImportCounts { get; set; } = [];//what was imported and what skipped, by why
+		public string ImportError { get; set; }
+		public string ImportFrom { get; set; }//the archive's actor
+		public bool ImportSameActor { get; set; }
+	}
+
+	// the parts of an archive to import: posts (with their media), profile, follows, blocks, mutes, domainblocks, lists,
+	// bookmarks, filters, tags, notificationpolicy, pins; and only when asked, located, scheduled, likes (which tell their
+	// authors)
+	public class ImportPersonaArchiveForm
+	{
+		public string UploadId { get; set; }
+		public List<string> Parts { get; set; } = [];
+	}
+
+	public class ViewArchiveTicket
+	{
+		public string Url { get; set; }
+		public DateTime ExpiresAt { get; set; }
+		public long Bytes { get; set; }
+	}
+
+	public class ViewArchiveUpload
+	{
+		public string Id { get; set; }
+		public long Received { get; set; }
+		public long ChunkBytes { get; set; }
+	}
+}

PrivaPub.ClientModels/User/ViewStorage.cs

@@ -0,0 +1,11 @@
+namespace PrivaPub.ClientModels.User
+{
+	// /clientapi/user/storage: what the login's media take (every persona's uploads and pictures), and its quota when the
+	// server sets one
+	public class ViewStorage
+	{
+		public long MediaBytes { get; set; }
+		public long MediaFiles { get; set; }
+		public long? QuotaBytes { get; set; }
+	}
+}

PrivaPub.Tests/Domain/ContentRendererTests.cs

@@ -68,7 +68,10 @@ namespace PrivaPub.Tests.Domain
 
 			public Task<LocalActor> FindById(LocalActorKind kind, string id, CancellationToken token) => throw new NotSupportedException();
 			public Task<LocalActor> FindByUri(string actorUri, CancellationToken token) => throw new NotSupportedException();
+			public Task<LocalActor> FindByAddress(string address, CancellationToken token) => throw new NotSupportedException();
 			public Task<LocalActor> GetInstanceActor(CancellationToken token) => throw new NotSupportedException();
+			public Task<LocalActor> GetReporterActor(CancellationToken token) => throw new NotSupportedException();
+			public Task<LocalActor> GetReaderActor(CancellationToken token) => throw new NotSupportedException();
 			public Task<bool> IsUserNameTaken(string userName, CancellationToken token) => throw new NotSupportedException();
 			public Task<bool> TryReserveUserName(string userName, LocalActorKind kind, string ownerId, CancellationToken token) => throw new NotSupportedException();
 			public LocalActor FromAvatar(Avatar avatar) => throw new NotSupportedException();

PrivaPub.Tests/Domain/MediaFlowTests.cs

@@ -1,3 +1,4 @@
+using PrivaPub.Models.Federation;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Caching.Memory;
 
@@ -46,7 +47,7 @@ namespace PrivaPub.Tests.Domain
 			var (_, alice) = await _harness.Persona("alice");
 			var (_, mallory) = await _harness.Persona("mallory");
 
-			var upload = await _harness.Media.Upload(alice, Upload(Png(300, 200), "image/png"), "a blue square", "0.25,-0.5", token);
+			var upload = await _harness.Media.Upload(alice, Upload(Png(300, 200), "image/png"), "a blue square", "0.25,-0.5", false, token);
 			Assert.True(upload.Ok);
 			Assert.True(File.Exists(Path.Combine(_harness.Media.Root, upload.Attachment.FilePath)));
 
@@ -73,7 +74,7 @@ namespace PrivaPub.Tests.Domain
 		{
 			var (_, alice) = await _harness.Persona("alice");
 
-			var outcome = await _harness.Media.Upload(alice, Upload(System.Text.Encoding.UTF8.GetBytes("<svg/>"), "image/svg+xml"), default, default, TestContext.Current.CancellationToken);
+			var outcome = await _harness.Media.Upload(alice, Upload(System.Text.Encoding.UTF8.GetBytes("<svg/>"), "image/svg+xml"), default, default, false, TestContext.Current.CancellationToken);
 
 			Assert.False(outcome.Ok);
 			Assert.Equal(422, outcome.Status);
@@ -98,5 +99,62 @@ namespace PrivaPub.Tests.Domain
 			Assert.StartsWith(_harness.Media.ProxyRoot, file);
 			Assert.Null(tampered);
 		}
+
+		// a login over its quota uploads nothing more, whichever persona tries
+		[Fact]
+		public async Task A_login_over_its_quota_uploads_nothing_more()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var (_, sibling) = await _harness.Persona("sibling", root);
+			var quota = new MediaService(new StaticOptions<MediaOptions>(new MediaOptions { Root = _harness.Media.Root, QuotaBytesPerRoot = 3000 }),
+				_harness.Local, default, Microsoft.Extensions.Logging.Abstractions.NullLogger<MediaService>.Instance);
+			// noise: its PNG is about as big as its pixels, so two of them are over the quota and one is not
+			static byte[] Noise()
+			{
+				var pixels = new byte[30 * 20 * 3];
+				Random.Shared.NextBytes(pixels);
+				using var image = NetVips.Image.NewFromMemory(pixels, 30, 20, 3, NetVips.Enums.BandFormat.Uchar);
+				return image.WriteToBuffer(".png");
+			}
+
+			Assert.True((await quota.Upload(alice, Upload(Noise(), "image/png"), default, default, false, token)).Ok);
+			var full = await quota.Upload(sibling, Upload(Noise(), "image/png"), default, default, false, token);
+
+			Assert.False(full.Ok);
+			Assert.Contains("storage is full", full.Error);
+		}
+
+		// nothing of a suspended server, or of one whose media are rejected, is proxied; blocking one purges what was cached
+		[Fact]
+		public async Task A_blocked_servers_media_are_not_proxied_and_their_cache_goes()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var path = $"/files/{Guid.NewGuid():N}.png";
+			_harness.Peer.ServeFile(path, Png(10, 10), "image/png");
+			var remote = _harness.Peer.A + path;
+			var host = new Uri(remote).Host;
+			var blocks = new Blocks();
+			var proxy = new MediaProxy(_harness.Local, Peer.Http(), _harness.Media, new StaticOptions<MediaOptions>(new MediaOptions()), blocks);
+			Assert.Equal(ProxyOutcome.Cached, (await proxy.Download(remote, token)).Outcome);
+
+			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Silence, RejectMedia = true };
+			Assert.True(proxy.Refuses(remote));
+			Assert.True(proxy.Purge(host) >= 1);
+			Assert.Equal(default, proxy.Cached(remote));
+
+			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Silence };
+			Assert.False(proxy.Refuses(remote));
+			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Suspend };
+			Assert.True(proxy.Refuses(remote));
+		}
+
+		sealed class Blocks : PrivaPub.Federation.Moderation.IDomainBlocks
+		{
+			public Dictionary<string, DomainBlock> Blocked { get; } = new();
+			public DomainBlock Find(string host) => Blocked.GetValueOrDefault(host);
+			public bool IsSuspended(string host) => Find(host)?.Severity == DomainBlockSeverity.Suspend;
+			public Task Reload(CancellationToken token) => Task.CompletedTask;
+		}
 	}
 }

PrivaPub.Tests/Domain/MediaProcessingTests.cs

@@ -19,6 +19,37 @@ namespace PrivaPub.Tests.Domain
 			return tagged.WriteToBuffer(".jpg");
 		}
 
+		// SVG, PDF and the other formats libvips could read never load from an upload, whatever it claims to be
+		[Fact]
+		public void Only_the_upload_formats_are_ever_loaded()
+		{
+			var svg = "<svg xmlns='http://www.w3.org/2000/svg' width='20000' height='20000'><rect width='10' height='10'/></svg>"u8.ToArray();
+			Assert.Throws<VipsException>(() => MediaService.Inspect(svg));
+			Assert.Throws<VipsException>(() => MediaService.Inspect("%PDF-1.4\n1 0 obj<<>>endobj\ntrailer<<>>\n%%EOF"u8.ToArray()));
+			using var colour = (Image.Black(8, 8, bands: 3) + 100).Cast(Enums.BandFormat.Uchar);
+			foreach (var format in new[] { ".jpg", ".png", ".gif", ".webp" })
+				Assert.Equal(8, MediaService.Inspect(colour.WriteToBuffer(format)).Width);
+			Assert.Throws<VipsException>(() => MediaService.Inspect(colour.WriteToBuffer(".tif")));
+		}
+
+		// the header tells how big an image would decode before anything is decoded
+		[Fact]
+		public void The_header_says_how_big_an_image_would_decode()
+		{
+			using var huge = Image.Black(8000, 6000);
+			var header = MediaService.Inspect(huge.WriteToBuffer(".png"));
+			Assert.Equal(48_000_000, header.Pixels);
+			Assert.False(header.Animated);
+
+			using var frame = (Image.Black(40, 30, bands: 3) + 60).Cast(Enums.BandFormat.Uchar);
+			using var frames = Image.Arrayjoin(new[] { frame, frame + 80, frame + 160 }, across: 1).Cast(Enums.BandFormat.Uchar);
+			using var paged = frames.Mutate(m => m.Set(GValue.GIntType, "page-height", 30));
+			var gif = MediaService.Inspect(paged.WriteToBuffer(".gif"));
+			Assert.True(gif.Animated);
+			Assert.Equal(3, gif.Pages);
+			Assert.Equal(40 * 30 * 3, gif.Pixels);
+		}
+
 		[Fact]
 		public void Uploaded_images_lose_every_kind_of_metadata()
 		{
@@ -26,7 +57,7 @@ namespace PrivaPub.Tests.Domain
 			using (var original = Image.NewFromBuffer(input))
 				Assert.Contains("exif-data", original.GetFields());
 
-			var processed = MediaService.ProcessImage(input, 4096, 640, animated: false);
+			var processed = MediaService.ProcessImage(input, 4096, 640);
 
 			using var output = Image.NewFromBuffer(processed.Bytes);
 			var fields = output.GetFields();
@@ -44,7 +75,7 @@ namespace PrivaPub.Tests.Domain
 		[Fact]
 		public void Large_images_are_capped()
 		{
-			var processed = MediaService.ProcessImage(JpegWithMetadata(5000, 2500), 4096, 640, animated: false);
+			var processed = MediaService.ProcessImage(JpegWithMetadata(5000, 2500), 4096, 640);
 
 			Assert.Equal((4096, 2048), (processed.Width, processed.Height));
 		}
@@ -52,7 +83,7 @@ namespace PrivaPub.Tests.Domain
 		[Fact]
 		public void A_blurhash_is_well_formed()
 		{
-			var processed = MediaService.ProcessImage(JpegWithMetadata(64, 64), 4096, 640, animated: false);
+			var processed = MediaService.ProcessImage(JpegWithMetadata(64, 64), 4096, 640);
 
 			Assert.Equal(28, processed.Blurhash.Length);
 			Assert.Equal('L', processed.Blurhash[0]);

PrivaPub.Tests/Domain/NearbyTests.cs

@@ -59,6 +59,8 @@ namespace PrivaPub.Tests.Domain
 				.Select(j => JsonSerializer.Deserialize<DeliveryPayload>(j.Payload))
 				.Where(p => p.Body.Contains(post.ID));
 			Assert.Empty(outgoing);
+			// nor reaches a home, its author's included: the Mastodon API looks past it, so there it could not be acted on
+			Assert.False(await DB.Default.Find<PrivaPub.Models.Social.TimelineEntry>().Match(e => e.PostId == post.ID).ExecuteAnyAsync(token));
 		}
 
 		[Fact]

PrivaPub.Tests/Federation/BackfillTests.cs

@@ -0,0 +1,78 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// a follow that holds reads the account's latest public posts from its outbox, so its profile is not empty
+	[Trait("Category", "Integration")]
+	public sealed class BackfillTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task An_accepted_follow_reads_the_accounts_latest_public_posts_from_its_outbox()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var mallory = new RemoteActor(_harness.Peer, "mallory", _harness.Peer.B);
+			var origin = new Uri(bob.Id).GetLeftPart(UriPartial.Authority);
+			JsonObject Note(string id, string text, RemoteActor author) => new()
+			{
+				["id"] = id, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"), ["published"] = DateTime.UtcNow.ToString("O")
+			};
+			var older = $"{origin}/notes/{Guid.NewGuid():N}";
+			var newer = $"{origin}/notes/{Guid.NewGuid():N}";
+			var notBobs = $"{new Uri(mallory.Id).GetLeftPart(UriPartial.Authority)}/notes/{Guid.NewGuid():N}";
+			_harness.Peer.Serve(new Uri(older).AbsolutePath, Note(older, "an older post", bob).ToJsonString());
+			_harness.Peer.Serve(new Uri(newer).AbsolutePath, Note(newer, "a newer post", bob).ToJsonString());
+			_harness.Peer.Serve(new Uri(bob.Id).AbsolutePath + "/outbox", new JsonObject
+			{
+				["id"] = bob.Id + "/outbox", ["type"] = "OrderedCollection", ["totalItems"] = 4,
+				["orderedItems"] = new JsonArray(
+					new JsonObject { ["type"] = "Create", ["object"] = Note(newer, "a newer post", bob) },
+					new JsonObject { ["type"] = "Announce", ["object"] = notBobs },
+					new JsonObject { ["type"] = "Create", ["object"] = notBobs },
+					new JsonObject { ["type"] = "Create", ["object"] = older })
+			}.ToJsonString());
+			var account = await _harness.Remote.GetActor(bob.Id, refresh: false, token);
+			var followId = alice.ActivityUri($"follow-{Guid.NewGuid():N}");
+			await DB.Default.SaveAsync(new Following
+			{
+				AvatarId = alice.Id, TargetActorURI = bob.Id, TargetAccountId = account.ID, State = FollowState.Requested, FollowActivityURI = followId
+			}, token);
+
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{bob.Id}#accept-{Guid.NewGuid():N}", ["type"] = "Accept", ["actor"] = bob.Id,
+				["object"] = new JsonObject { ["id"] = followId, ["type"] = "Follow", ["actor"] = alice.Uri, ["object"] = bob.Id }
+			});
+			var job = await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.BackfillOutbox && j.Payload == bob.Id).ExecuteSingleAsync(token);
+			await new OutboxBackfill(_harness.Db, _harness.Remote, _harness.RemotePosts).Handle(job, token);
+
+			var held = (await DB.Default.Find<Post>().Match(p => p.ActorURI == bob.Id).ExecuteAsync(token)).Select(p => p.ObjectURI).ToHashSet();
+			Assert.Equal(new HashSet<string> { older, newer }, held);
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ObjectURI == notBobs).ExecuteAnyAsync(token));
+		}
+	}
+}

PrivaPub.Tests/Federation/ChatMessageSoftwareTests.cs

@@ -0,0 +1,75 @@
+using MongoDB.Entities;
+
+using PrivaPub.ClientModels.Post;
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// alone in its collection: every test's peer is 127.0.0.1, and the server row it writes decides for whoever writes there
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class ChatMessageSoftwareTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static string NewId(RemoteActor actor, string kind) => $"{new Uri(actor.Id).GetLeftPart(UriPartial.Authority)}/{kind}/{Guid.NewGuid():N}";
+
+		// the one decision taken by a server's software (owner decision 2026-10-05): Lemmy before 1.0 and Mbin get a
+		// ChatMessage even from a persona answering a Note; Lemmy 1.0 a Note
+		[Theory]
+		[InlineData("lemmy", "0.19.20", "ChatMessage")]
+		[InlineData("mbin", "1.10.1", "ChatMessage")]
+		[InlineData("lemmy", "1.0.0-beta.2", "Note")]
+		public async Task A_direct_message_to_lemmy_before_1_0_or_mbin_is_a_chat_message(string software, string version, string sent)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var sender = new RemoteActor(_harness.Peer, "pm");
+			var host = new Uri(sender.Id).Host;
+			await DB.Default.DeleteAsync<PrivaPub.Models.Jobs.RemoteInstance>(i => i.Host == host);
+			await DB.Default.SaveAsync(new PrivaPub.Models.Jobs.RemoteInstance { Host = host, Software = software, SoftwareVersion = version }, token);
+			try
+			{
+				var id = NewId(sender, "messages");
+				await _harness.Deliver(sender, "/human-centipede", new JsonObject
+				{
+					["id"] = NewId(sender, "activities/create"), ["type"] = "Create", ["actor"] = sender.Id, ["to"] = new JsonArray(alice.Uri),
+					["object"] = new JsonObject
+					{
+						["id"] = id, ["type"] = "Note", ["attributedTo"] = sender.Id, ["to"] = new JsonArray(alice.Uri),
+						["content"] = "<p>psst</p>", ["published"] = DateTime.UtcNow.ToString("O")
+					}
+				});
+				var message = await DB.Default.Find<Post>().Match(p => p.ObjectURI == id).ExecuteSingleAsync(token);
+
+				var answer = await _harness.Statuses.Publish(alice, new PrivaPub.Domain.Statuses.StatusDraft
+				{
+					Text = "psst back", Visibility = PostVisibility.Direct, ConversationId = message.ConversationId
+				}, token);
+
+				Assert.True(answer.Ok, answer.Error);
+				var create = (await _harness.Outgoing(sender.Id + "/inbox")).Last(a => a["type"]!.GetValue<string>() == "Create");
+				Assert.Equal(sent, create["object"]!["type"]!.GetValue<string>());
+			}
+			finally
+			{
+				await DB.Default.DeleteAsync<PrivaPub.Models.Jobs.RemoteInstance>(i => i.Host == host);
+			}
+		}
+	}
+}

PrivaPub.Tests/Federation/CommunityEditsTests.cs

@@ -30,11 +30,12 @@ namespace PrivaPub.Tests.Federation
 
 		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
 
-		async Task<(RemoteActor Community, RemoteActor Poster, JsonObject Note, Post Post)> Announced()
+		// a post in a community the persona follows; the community on the poster's server unless another origin is given
+		async Task<(RemoteActor Community, RemoteActor Poster, JsonObject Note, Post Post)> Announced(string communityOrigin = default)
 		{
 			var token = TestContext.Current.CancellationToken;
 			var (root, alice) = await _harness.Persona("alice");
-			var community = new RemoteActor(_harness.Peer, "cats", type: "Group");
+			var community = new RemoteActor(_harness.Peer, "cats", communityOrigin, type: "Group");
 			var poster = new RemoteActor(_harness.Peer, "poster");
 			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = community.Id }, token);
 			await DB.Default.Update<Following>().Match(f => f.AvatarId == alice.Id).Modify(f => f.State, FollowState.Accepted).ExecuteAsync(token);
@@ -109,6 +110,97 @@ namespace PrivaPub.Tests.Federation
 			Assert.True(await DB.Default.Find<DeletedObject>().Match(d => d.ObjectURI == post.ObjectURI).ExecuteAnyAsync(token));
 		}
 
+		// PieFed keeps serving a thread its moderator removed: a community on the post's own server speaks for it
+		[Fact]
+		public async Task A_removal_a_community_on_the_posts_server_announces_is_taken_though_the_post_is_still_served()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (community, poster, note, post) = await Announced();
+
+			await Announce(community, new JsonObject
+			{
+				["id"] = $"{Origin(poster)}/delete/{Guid.NewGuid():N}", ["type"] = "Delete", ["actor"] = poster.Id,
+				["object"] = note["id"]!.GetValue<string>(), ["summary"] = "off topic"
+			});
+
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ID == post.ID).ExecuteAnyAsync(token));
+		}
+
+		[Fact]
+		public async Task A_removal_a_community_elsewhere_announces_waits_for_the_posts_server_to_say_it_is_gone()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (community, poster, note, post) = await Announced(_harness.Peer.B);
+			var delete = new JsonObject
+			{
+				["id"] = $"{Origin(community)}/delete/{Guid.NewGuid():N}", ["type"] = "Delete", ["actor"] = community.Id,
+				["object"] = note["id"]!.GetValue<string>()
+			};
+
+			await Announce(community, (JsonObject)delete.DeepClone());
+			var kept = await DB.Default.Find<Post>().Match(p => p.ID == post.ID).ExecuteAnyAsync(token);
+			_harness.Peer.Serve(new Uri(note["id"]!.GetValue<string>()).AbsolutePath, new JsonObject { ["id"] = note["id"]!.GetValue<string>(), ["type"] = "Tombstone" }.ToJsonString());
+			delete["id"] = $"{Origin(community)}/delete/{Guid.NewGuid():N}";
+			await Announce(community, delete);
+
+			Assert.True(kept);
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ID == post.ID).ExecuteAnyAsync(token));
+		}
+
+		// Mbin sends a magazine's thread to its subscribers as the author's Create, and a moderator's lock as it is, with no
+		// announce: the magazine's server speaks for them, another server does not
+		[Fact]
+		public async Task A_thread_and_its_lock_that_a_followed_groups_own_server_sends_without_announcing_them_are_taken()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var magazine = new RemoteActor(_harness.Peer, "books", type: "Group");
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var stranger = new RemoteActor(_harness.Peer, "stranger", _harness.Peer.B);
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = magazine.Id }, token);
+			await DB.Default.Update<Following>().Match(f => f.AvatarId == alice.Id).Modify(f => f.State, FollowState.Accepted).ExecuteAsync(token);
+			JsonObject Page(RemoteActor author) => new()
+			{
+				["id"] = $"{Origin(author)}/m/books/t/{Guid.NewGuid():N}", ["type"] = "Page", ["name"] = "a thread",
+				["attributedTo"] = author.Id, ["content"] = "<p>in the magazine</p>",
+				["to"] = new JsonArray(magazine.Id, Addressing.Public), ["cc"] = new JsonArray(author.Id + "/followers"),
+				["audience"] = magazine.Id, ["published"] = DateTime.UtcNow.ToString("O")
+			};
+			JsonObject Create(RemoteActor author, JsonObject page) => new()
+			{
+				["id"] = $"{Origin(author)}/f/object/{Guid.NewGuid():N}", ["type"] = "Create", ["actor"] = author.Id,
+				["to"] = page["to"]!.DeepClone(), ["cc"] = page["cc"]!.DeepClone(), ["object"] = page
+			};
+			JsonObject Lock(RemoteActor moderator, string uri) => new()
+			{
+				["id"] = $"{Origin(moderator)}/f/object/{Guid.NewGuid():N}", ["type"] = "Lock", ["actor"] = moderator.Id, ["object"] = uri
+			};
+			var page = Page(poster);
+			var elsewhere = Page(stranger);
+			var uri = page["id"]!.GetValue<string>();
+
+			await _harness.Deliver(poster, "/human-centipede", Create(poster, page));
+			await _harness.Deliver(stranger, "/human-centipede", Create(stranger, elsewhere));
+			var kept = await DB.Default.Find<Post>().Match(p => p.ObjectURI == uri).ExecuteSingleAsync(token);
+			await _harness.Deliver(stranger, "/human-centipede", Lock(stranger, uri));
+			var lockedByStranger = (await DB.Default.Find<Post>().OneAsync(kept.ID, token)).LockedAt;
+			var moderator = new RemoteActor(_harness.Peer, "moderator");
+			var locking = Lock(moderator, uri);
+			await _harness.Deliver(moderator, "/human-centipede", locking);
+			var locked = (await DB.Default.Find<Post>().OneAsync(kept.ID, token)).LockedAt;
+			await _harness.Deliver(moderator, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(moderator)}/f/object/{Guid.NewGuid():N}", ["type"] = "Undo", ["actor"] = moderator.Id, ["object"] = locking.DeepClone()
+			});
+
+			Assert.Equal(magazine.Id, kept.AudienceURI);
+			Assert.True(await DB.Default.Find<TimelineEntry>().Match(e => e.PostId == kept.ID && e.AvatarId == alice.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ObjectURI == elsewhere["id"]!.GetValue<string>()).ExecuteAnyAsync(token));
+			Assert.Null(lockedByStranger);
+			Assert.NotNull(locked);
+			Assert.Null((await DB.Default.Find<Post>().OneAsync(kept.ID, token)).LockedAt);
+		}
+
 		[Fact]
 		public async Task A_fetched_object_does_not_wear_the_signature_of_the_activity_that_caused_the_fetch()
 		{

PrivaPub.Tests/Federation/CommunityModerationTests.cs

@@ -0,0 +1,115 @@
+using MongoDB.Entities;
+
+using PrivaPub.ClientModels.Post;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	[Trait("Category", "Integration")]
+	public sealed class CommunityModerationTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static string Origin(string id) => new Uri(id).GetLeftPart(UriPartial.Authority);
+
+		// a Lemmy community on the peer's first origin whose moderators collection lists the given accounts
+		RemoteActor Community(params RemoteActor[] moderators)
+		{
+			var community = new RemoteActor(_harness.Peer, "comm", type: "Group");
+			var document = community.Document();
+			document["attributedTo"] = community.Id + "/moderators";
+			_harness.Peer.Serve($"/users/{community.Name}", document.ToJsonString());
+			_harness.Peer.Serve($"/users/{community.Name}/moderators", new JsonObject
+			{
+				["id"] = community.Id + "/moderators", ["type"] = "OrderedCollection",
+				["orderedItems"] = new JsonArray(moderators.Select(m => (JsonNode)m.Id).ToArray())
+			}.ToJsonString());
+			return community;
+		}
+
+		async Task<(Post Post, PrivaPub.Federation.Actors.LocalActor Alice)> PostIn(RemoteActor community)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			await _harness.Posts.InsertPost(root, new InsertPostForm { AvatarId = alice.Id, Text = "in the community" }, token);
+			var post = await DB.Default.Find<Post>().Match(p => p.GroupUserId == alice.Id).ExecuteFirstAsync(token);
+			await DB.Default.Update<Post>().MatchID(post.ID).Modify(p => p.AudienceURI, community.Id).ExecuteAsync(token);
+			await _harness.Remote.GetActor(community.Id, refresh: true, token);
+			return (post, alice);
+		}
+
+		JsonObject Warn(RemoteActor moderator, RemoteActor community, string persona, string post) => new()
+		{
+			["id"] = $"{Origin(moderator.Id)}/activities/warn/{Guid.NewGuid():N}", ["type"] = "Warn", ["actor"] = moderator.Id,
+			["to"] = new JsonArray(persona), ["object"] = post, ["summary"] = "please keep it civil", ["audience"] = community.Id
+		};
+
+		[Fact]
+		public async Task A_warning_from_the_communitys_moderators_reaches_the_persona_and_a_strangers_does_not()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var listed = new RemoteActor(_harness.Peer, "listedmod", origin: _harness.Peer.B);
+			var stranger = new RemoteActor(_harness.Peer, "stranger", origin: _harness.Peer.B);
+			var community = Community(listed);
+			var admin = new RemoteActor(_harness.Peer, "admin");
+			var (post, alice) = await PostIn(community);
+
+			await _harness.Deliver(stranger, "/human-centipede", Warn(stranger, community, alice.Uri, post.ObjectURI));
+			Assert.False(await DB.Default.Find<Notification>().Match(n => n.AvatarId == alice.Id && n.Type == NotificationType.ModerationWarning).ExecuteAnyAsync(token));
+
+			await _harness.Deliver(listed, "/human-centipede", Warn(listed, community, alice.Uri, post.ObjectURI));
+			var warning = await DB.Default.Find<Notification>().Match(n => n.AvatarId == alice.Id && n.Type == NotificationType.ModerationWarning).ExecuteFirstAsync(token);
+			Assert.Equal("please keep it civil", warning.Text);
+			Assert.Equal(post.ID, warning.PostId);
+
+			var adminWarning = Warn(admin, community, alice.Uri, post.ObjectURI);
+			adminWarning["summary"] = "from the server's admin";
+			await DB.Default.DeleteAsync<Notification>(n => n.AvatarId == alice.Id);
+			await _harness.Deliver(admin, "/human-centipede", adminWarning);
+			Assert.Equal("from the server's admin", (await DB.Default.Find<Notification>().Match(n => n.AvatarId == alice.Id && n.Type == NotificationType.ModerationWarning).ExecuteFirstAsync(token)).Text);
+		}
+
+		[Fact]
+		public async Task A_reports_resolution_is_kept_only_from_the_server_holding_what_was_reported()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var community = Community();
+			var (post, _) = await PostIn(community);
+			var report = new Report { PostIds = new() { post.ID }, Comment = "spam" };
+			await DB.Default.SaveAsync(report, token);
+			var flag = $"{_harness.Local.BaseAddress}/peasants/privapub_reports/grunts/flag-{report.ID}-1";
+			JsonObject Resolve(RemoteActor by) => new()
+			{
+				["id"] = $"{Origin(by.Id)}/activities/resolve/{Guid.NewGuid():N}", ["type"] = "Resolve", ["actor"] = by.Id, ["to"] = new JsonArray(community.Id),
+				["object"] = new JsonObject { ["id"] = flag, ["type"] = "Flag", ["actor"] = $"{_harness.Local.BaseAddress}/peasants/privapub_reports", ["object"] = post.ObjectURI }
+			};
+			var elsewhere = new RemoteActor(_harness.Peer, "elsewhere", origin: _harness.Peer.B);
+			var moderator = new RemoteActor(_harness.Peer, "moderator");
+
+			await _harness.Deliver(elsewhere, "/human-centipede", Resolve(elsewhere));
+			Assert.Null((await DB.Default.Find<Report>().OneAsync(report.ID, token)).RemoteResolvedAt);
+
+			await _harness.Deliver(moderator, "/human-centipede", Resolve(moderator));
+			var resolved = await DB.Default.Find<Report>().OneAsync(report.ID, token);
+			Assert.NotNull(resolved.RemoteResolvedAt);
+			Assert.Equal(moderator.Id, resolved.RemoteResolvedBy);
+			Assert.False(resolved.IsResolved);
+		}
+	}
+}

PrivaPub.Tests/Federation/ContextTests.cs

@@ -0,0 +1,32 @@
+using PrivaPub.Federation.Rendering;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// The @context on everything we send. Readers that expand JSON-LD 1.0 (Smithereen) refuse a whole document over one
+	// term only 1.1 knows, so every term stays within 1.0
+	public class ContextTests
+	{
+		static readonly string[] Containers10 = ["@list", "@set", "@index", "@language"];
+		static readonly string[] Keywords11 = ["@version", "@protected", "@propagate", "@import", "@nest", "@prefix", "@context", "@direction", "@json"];
+
+		[Fact]
+		public void Every_term_is_json_ld_1_0()
+		{
+			var terms = ActivityPubRenderer.Context().OfType<JsonObject>().Single();
+
+			foreach (var (name, definition) in terms)
+			{
+				if (definition is not JsonObject term)
+					continue;
+				if (term["@container"] is JsonValue container)
+					Assert.True(Containers10.Contains(container.GetValue<string>()), $"{name}: @container {container} is JSON-LD 1.1");
+				Assert.True(term["@container"] is null or JsonValue, $"{name}: an array of containers is JSON-LD 1.1");
+				Assert.DoesNotContain(term.Select(p => p.Key), Keywords11.Contains);
+				Assert.NotEqual("@json", term["@type"]?.GetValue<string>());
+			}
+			Assert.DoesNotContain(terms.Select(p => p.Key), Keywords11.Contains);
+		}
+	}
+}

PrivaPub.Tests/Federation/ConversationContainerTests.cs

@@ -0,0 +1,142 @@
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Jobs;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Tests.Federation
+{
+	// FEP-171b: a thread's owner adds a reply someone else wrote to the thread's context (Hubzilla's Add{Create}), and the
+	// reply is taken as passed on by the owner, on its own proof; an Add aimed at a collection elsewhere is not a thread's
+	[Trait("Category", "Integration")]
+	public sealed class ConversationContainerTests : IAsyncLifetime
+	{
+		const string Public = "https://www.w3.org/ns/activitystreams#Public";
+
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+
+		static JsonObject Create(RemoteActor author, string text, string context, string inReplyTo = default)
+		{
+			var noteId = $"{Origin(author)}/item/{Guid.NewGuid():N}";
+			var note = new JsonObject
+			{
+				["id"] = noteId, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>", ["context"] = context,
+				["to"] = new JsonArray(Public), ["published"] = DateTime.UtcNow.ToString("O")
+			};
+			if (inReplyTo != default)
+				note["inReplyTo"] = inReplyTo;
+			return new JsonObject
+			{
+				["id"] = $"{Origin(author)}/activity/{Guid.NewGuid():N}", ["type"] = "Create", ["actor"] = author.Id, ["to"] = new JsonArray(Public),
+				["object"] = note
+			};
+		}
+
+		async Task<bool> Held(string objectUri) => await DB.Default.Find<PostEntity>().Match(p => p.ObjectURI == objectUri).ExecuteAnyAsync(Token);
+
+		async Task RunQueued(string innerId)
+		{
+			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == "inbox|forwarded|" + innerId && j.State == JobState.Pending).ExecuteFirstAsync(Token);
+			Assert.NotNull(job);
+			Assert.Equal(JobResult.Done, (await _harness.Processor.Handle(job, Token)).Result);
+		}
+
+		[Fact]
+		public async Task A_reply_the_threads_owner_adds_to_its_context_is_taken_on_its_proof()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var owner = new RemoteActor(_harness.Peer, "owner", ed25519: true);
+			var commenter = new RemoteActor(_harness.Peer, "commenter", ed25519: true);
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = owner.Id, TargetInboxURL = owner.Id + "/inbox", State = FollowState.Accepted }, Token);
+			var context = $"{Origin(owner)}/conversation/{Guid.NewGuid():N}";
+			var root = Create(owner, "a thread", context);
+			await _harness.Deliver(owner, "/human-centipede", root);
+			var rootId = root["object"]!["id"]!.GetValue<string>();
+			Assert.True(await Held(rootId));
+
+			var reply = commenter.Prove(Create(commenter, "a reply in it", context, rootId));
+			var replyId = reply["object"]!["id"]!.GetValue<string>();
+			await _harness.Deliver(owner, "/human-centipede", owner.Prove(new JsonObject
+			{
+				["id"] = $"{Origin(owner)}/activity/{Guid.NewGuid():N}", ["type"] = "Add", ["actor"] = owner.Id, ["object"] = reply,
+				["target"] = new JsonObject { ["id"] = context, ["type"] = "Collection", ["attributedTo"] = owner.Id }, ["to"] = new JsonArray(Public)
+			}));
+			await RunQueued(reply["id"]!.GetValue<string>());
+
+			var stored = await DB.Default.Find<PostEntity>().Match(p => p.ObjectURI == replyId).ExecuteFirstAsync(Token);
+			Assert.NotNull(stored);
+			Assert.Equal(commenter.Id, stored.ActorURI);
+			Assert.Equal((await DB.Default.Find<PostEntity>().Match(p => p.ObjectURI == rootId).ExecuteFirstAsync(Token)).ID, stored.AnsweringToPostId);
+		}
+
+		// Forte gives a post's Update the id of its Create, and sends it only added to the thread's context
+		[Fact]
+		public async Task An_update_added_under_its_creates_id_is_taken_as_the_edit()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var owner = new RemoteActor(_harness.Peer, "owner", ed25519: true);
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = owner.Id, TargetInboxURL = owner.Id + "/inbox", State = FollowState.Accepted }, Token);
+			var context = $"{Origin(owner)}/conversation/{Guid.NewGuid():N}";
+			var create = owner.Prove(Create(owner, "as first written", context));
+			JsonObject Added(JsonObject inner) => owner.Prove(new JsonObject
+			{
+				["id"] = $"{Origin(owner)}/activity/{Guid.NewGuid():N}", ["type"] = "Add", ["actor"] = owner.Id, ["object"] = inner,
+				["target"] = new JsonObject { ["id"] = context, ["type"] = "Collection", ["attributedTo"] = owner.Id }
+			});
+			await _harness.Deliver(owner, "/human-centipede", Added(create));
+			await RunQueued(create["id"]!.GetValue<string>());
+			var update = create.DeepClone().AsObject();
+			update.Remove("proof");
+			update["type"] = "Update";
+			update["object"]!["content"] = "<p>as edited</p>";
+			update["object"]!["updated"] = DateTime.UtcNow.AddSeconds(1).ToString("O");
+			owner.Prove(update);
+
+			await _harness.Deliver(owner, "/human-centipede", Added(update));
+			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey.StartsWith("inbox|forwarded|" + update["id"]!.GetValue<string>() + "|") && j.State == JobState.Pending)
+				.ExecuteFirstAsync(Token);
+			Assert.NotNull(job);
+			Assert.Equal(JobResult.Done, (await _harness.Processor.Handle(job, Token)).Result);
+
+			var noteId = create["object"]!["id"]!.GetValue<string>();
+			Assert.Contains("as edited", (await DB.Default.Find<PostEntity>().Match(p => p.ObjectURI == noteId).ExecuteFirstAsync(Token)).ContentHtml);
+		}
+
+		[Fact]
+		public async Task An_add_to_a_collection_on_another_server_is_no_threads()
+		{
+			var owner = new RemoteActor(_harness.Peer, "owner", ed25519: true);
+			var commenter = new RemoteActor(_harness.Peer, "commenter", _harness.Peer.B, ed25519: true);
+			var reply = commenter.Prove(Create(commenter, "elsewhere", $"{Origin(commenter)}/conversation/1"));
+
+			await _harness.Deliver(owner, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(owner)}/activity/{Guid.NewGuid():N}", ["type"] = "Add", ["actor"] = owner.Id, ["object"] = reply,
+				["target"] = $"{Origin(commenter)}/conversation/1"
+			});
+
+			Assert.False(await DB.Default.Find<Job>().Match(j => j.DedupeKey == "inbox|forwarded|" + reply["id"]!.GetValue<string>()).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Federation/FeaturedTests.cs

@@ -0,0 +1,143 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// pins across servers: an account elsewhere features its own posts (Add and Remove on its `featured` collection, and
+	// the collection itself), a community features posts made in it, and a persona's pin is told to its followers
+	[Trait("Category", "Integration")]
+	public sealed class FeaturedTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+
+		// a public note of the actor's, served where its id points
+		string Note(RemoteActor author, string text, string audience = default)
+		{
+			var path = $"/notes/{Guid.NewGuid():N}";
+			var note = new JsonObject
+			{
+				["id"] = Origin(author) + path, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"), ["published"] = DateTime.UtcNow.ToString("O")
+			};
+			if (audience != default)
+				note["audience"] = audience;
+			_harness.Peer.Serve(path, note.ToJsonString());
+			return Origin(author) + path;
+		}
+
+		JsonObject Featuring(RemoteActor actor, string type, string objectUri, string target = default) => new()
+		{
+			["id"] = $"{actor.Id}#{type}-{Guid.NewGuid():N}", ["type"] = type, ["actor"] = actor.Id, ["object"] = objectUri,
+			["target"] = target ?? actor.Id + "/featured"
+		};
+
+		Task<List<RemoteFeatured>> FeaturedBy(RemoteActor actor) =>
+			DB.Default.Find<RemoteFeatured>().Match(f => f.ActorURI == actor.Id).Sort(f => f.Position, Order.Ascending).ExecuteAsync(TestContext.Current.CancellationToken);
+
+		[Fact]
+		public async Task An_account_features_its_own_post_and_takes_it_back_but_nothing_else()
+		{
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var carol = new RemoteActor(_harness.Peer, "carol", _harness.Peer.B);
+			var mine = Note(bob, "pinned");
+			var theirs = Note(carol, "not bob's");
+			var older = Note(bob, "pinned before");
+
+			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", older));
+			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", mine));
+			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", theirs));
+			// Smithereen's wall is a collection of the actor's too, but no pin
+			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Add", Note(bob, "on the wall"), bob.Id + "/wall"));
+
+			Assert.Equal(new[] { mine, older }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == mine).ExecuteSingleAsync(TestContext.Current.CancellationToken);
+			Assert.Equal(post.ID, (await FeaturedBy(bob))[0].PostId);
+
+			await _harness.Deliver(bob, "/human-centipede", Featuring(bob, "Remove", mine));
+
+			Assert.Equal(new[] { older }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
+		}
+
+		[Fact]
+		public async Task The_featured_collection_is_read_in_its_order_from_the_accounts_own_server()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var first = Note(bob, "first pin");
+			var second = Note(bob, "second pin");
+			_harness.Peer.Serve(new Uri(bob.Id).AbsolutePath + "/featured", new JsonObject
+			{
+				["id"] = bob.Id + "/featured", ["type"] = "OrderedCollection", ["totalItems"] = 2,
+				["orderedItems"] = new JsonArray(new JsonObject { ["id"] = first, ["type"] = "Note" }, second)
+			}.ToJsonString());
+			var account = await _harness.Remote.GetActor(bob.Id, refresh: false, token);
+
+			await _harness.Featured.Sync(account, token);
+
+			Assert.Equal(new[] { first, second }, (await FeaturedBy(bob)).Select(f => f.ObjectURI));
+		}
+
+		[Fact]
+		public async Task A_personas_pin_and_unpin_reach_its_followers_as_add_and_remove()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var follower = new RemoteActor(_harness.Peer, "fan");
+			await _harness.FollowedBy(alice, follower);
+			await _harness.Posts.InsertPost(root, new PrivaPub.ClientModels.Post.InsertPostForm { AvatarId = alice.Id, Text = "worth a pin" }, token);
+			var post = await DB.Default.Find<Post>().Match(p => p.GroupUserId == alice.Id).ExecuteFirstAsync(token);
+
+			await _harness.Outbox.PublishFeatured(alice.Id, post, featured: true, token);
+			await _harness.Outbox.PublishFeatured(alice.Id, post, featured: false, token);
+
+			var sent = (await _harness.Outgoing(follower.SharedInbox)).Concat(await _harness.Outgoing(follower.Id + "/inbox"))
+				.Where(a => a["type"]!.GetValue<string>() is "Add" or "Remove").ToList();
+			Assert.Equal(new[] { "Add", "Remove" }, sent.Select(a => a["type"]!.GetValue<string>()));
+			Assert.All(sent, a => Assert.Equal((alice.PostUri(post.ID), alice.Featured), (a["object"]!.GetValue<string>(), a["target"]!.GetValue<string>())));
+		}
+
+		[Fact]
+		public async Task A_community_features_a_post_made_in_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "books", type: "Group");
+			var member = new RemoteActor(_harness.Peer, "reader", _harness.Peer.B);
+			var account = await _harness.Remote.GetActor(community.Id, refresh: false, token);
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = community.Id, TargetAccountId = account.ID, State = FollowState.Accepted }, token);
+			var post = Note(member, "a thread in the community", community.Id);
+
+			await _harness.Deliver(community, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{community.Id}#announce-{Guid.NewGuid():N}", ["type"] = "Announce", ["actor"] = community.Id,
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+				["object"] = new JsonObject
+				{
+					["id"] = $"{Origin(member)}/activities/{Guid.NewGuid():N}", ["type"] = "Add", ["actor"] = member.Id, ["object"] = post,
+					["target"] = community.Id + "/featured"
+				}
+			});
+
+			Assert.Equal(new[] { post }, (await FeaturedBy(community)).Select(f => f.ObjectURI));
+		}
+	}
+}

PrivaPub.Tests/Federation/FlairTests.cs

@@ -0,0 +1,68 @@
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Objects;
+
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	public class FlairTests
+	{
+		[Fact]
+		public void A_lemmy_posts_flair_is_described_by_its_community()
+		{
+			using var group = JsonDocument.Parse("""
+				{
+					"id": "https://lemmy.example/c/tenforward", "type": "Group", "preferredUsername": "tenforward", "inbox": "https://lemmy.example/c/tenforward/inbox",
+					"attributedTo": "https://lemmy.example/c/tenforward/moderators",
+					"tag": [{ "type": "CommunityPostTag", "id": "https://lemmy.example/c/tenforward/tag/news", "preferredUsername": "news",
+						"name": "News", "content": "What happened", "color": "color03" }]
+				}
+				""");
+			var community = ActorDocument.Parse(group.RootElement);
+			var page = NoteParser.Parse(JsonNode.Parse("""
+				{
+					"id": "https://lemmy.example/post/1", "type": "Page", "name": "Big news", "attributedTo": "https://lemmy.example/u/bo",
+					"tag": [{ "type": "CommunityPostTag", "id": "https://lemmy.example/c/tenforward/tag/news", "preferredUsername": "news" },
+						{ "type": "Mention", "href": "https://lemmy.example/c/tenforward", "name": "@tenforward@lemmy.example" }]
+				}
+				"""));
+
+			Assert.Equal("https://lemmy.example/c/tenforward/moderators", community.Moderators);
+			var flair = Assert.Single(ObjectShapes.Described(page.Flairs, community.Flairs));
+			Assert.Equal("News", flair.Name);
+			Assert.Equal("news", flair.Slug);
+			Assert.Equal("color03", flair.Color);
+			Assert.Equal("What happened", flair.Description);
+		}
+
+		[Fact]
+		public void Reads_piefeds_flairs_in_both_dialects_and_its_older_community_list()
+		{
+			var post = NoteParser.Parse(JsonNode.Parse("""
+				{
+					"id": "https://piefed.example/post/9", "type": "Page", "name": "A question", "attributedTo": "https://piefed.example/u/pf",
+					"tag": [{ "type": "lemmy:CommunityTag", "id": "https://piefed.example/c/ask/tag/3", "display_name": "Solved",
+						"text_color": "#ffffff", "background_color": "#2e7d32", "blur_images": false },
+						{ "type": "Hashtag", "href": "https://piefed.example/tag/q", "name": "#q" }]
+				}
+				"""));
+			using var group = JsonDocument.Parse("""
+				{
+					"id": "https://piefed.example/c/ask", "type": "Group", "preferredUsername": "ask", "inbox": "https://piefed.example/c/ask/inbox",
+					"lemmy:tagsForPosts": [{ "type": "lemmy:CommunityTag", "id": "https://piefed.example/c/ask/tag/4", "display_name": "Spoiler",
+						"text_color": "#000", "background_color": "red; background: url(x)", "blur_images": true }]
+				}
+				""");
+
+			var solved = Assert.Single(post.Flairs);
+			Assert.Equal("Solved", solved.Name);
+			Assert.Equal("#2e7d32", solved.BackgroundColor);
+			Assert.Equal("q", Assert.Single(post.Tags));
+			var spoiler = Assert.Single(ActorDocument.Parse(group.RootElement).Flairs);
+			Assert.True(spoiler.BlurImages);
+			Assert.Equal("#000", spoiler.TextColor);
+			Assert.Null(spoiler.BackgroundColor);
+		}
+	}
+}

PrivaPub.Tests/Federation/FollowersSynchronizationTests.cs

@@ -0,0 +1,282 @@
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Outbox;
+using PrivaPub.Federation.Signing;
+using PrivaPub.Infrastructure.Http;
+using PrivaPub.Infrastructure.Jobs;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// FEP-8fcf (owner decision 2026-10-06): a delivery addressed to a persona's followers tells the receiving server, in a signed
+	// header, a digest of the persona's followers there; the roll-call it names lists them, to that server only
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class FollowersSynchronizationTests : IAsyncLifetime
+	{
+		static readonly string[] PeerHosts = { "localhost", "127.0.0.1" };
+
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		[Fact]
+		public void The_digest_is_the_xor_of_each_ids_sha256_whatever_the_order()
+		{
+			Assert.Equal(new string('0', 64), FollowersSynchronization.Digest([]));
+			Assert.Equal(FollowersSynchronization.Digest(["https://a.example/users/one", "https://a.example/users/two"]),
+				FollowersSynchronization.Digest(["https://a.example/users/two", "https://a.example/users/one"]));
+			Assert.Equal(Convert.ToHexStringLower(SHA256.HashData(Encoding.UTF8.GetBytes("https://a.example/users/one"))),
+				FollowersSynchronization.Digest(["https://a.example/users/one"]));
+		}
+
+		async Task<HttpRequestRecord> Delivered(LocalActor signer, string inbox, JsonObject activity)
+		{
+			await _harness.Delivery.Enqueue(signer, new[] { inbox }, activity, Token);
+			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == $"{activity["id"]!.GetValue<string>()}|{inbox}").ExecuteSingleAsync(Token);
+			var handler = new DeliveryJobHandler(_harness.Local, Peer.Http(), new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions())),
+				NullLogger<DeliveryJobHandler>.Instance);
+			Assert.Equal(JobResult.Done, (await handler.Handle(job, Token)).Result);
+			return Assert.Single(_harness.Peer.Requests, r => r.Body?.Contains(activity["id"]!.GetValue<string>()) == true);
+		}
+
+		static JsonObject Create(LocalActor author, params string[] to) => new()
+		{
+			["id"] = $"{author.Uri}/grunts/{Guid.NewGuid():N}", ["type"] = "Create", ["actor"] = author.Uri, ["to"] = new JsonArray(to.Select(t => (JsonNode)t).ToArray()),
+			["object"] = new JsonObject { ["type"] = "Note", ["content"] = "hi", ["to"] = new JsonArray(to.Select(t => (JsonNode)t).ToArray()) }
+		};
+
+		[Fact]
+		public async Task A_delivery_to_followers_carries_a_signed_digest_of_the_followers_on_that_server_only()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var one = new RemoteActor(_harness.Peer, "one");
+			var two = new RemoteActor(_harness.Peer, "two");
+			var far = new RemoteActor(_harness.Peer, "far", _harness.Peer.B);
+			await _harness.FollowedBy(alice, one);
+			await _harness.FollowedBy(alice, two);
+			await _harness.FollowedBy(alice, far);
+			await DB.Default.SaveAsync(new Follower
+			{
+				LocalActorId = alice.Id, LocalActorKind = alice.Kind, ActorURI = _harness.Peer.A + "/users/asking", InboxURL = _harness.Peer.A + "/users/asking/inbox", IsAccepted = false
+			}, Token);
+			_harness.Peer.Answer("/inbox", 202);
+
+			var received = await Delivered(alice, _harness.Peer.A + "/inbox", Create(alice, alice.Followers));
+
+			Assert.Equal(alice.Followers, Value(received, "collectionId"));
+			Assert.Equal(alice.Followers + "/roll-call", Value(received, "url"));
+			Assert.Equal(FollowersSynchronization.Digest([one.Id, two.Id]), Value(received, "digest"));
+			var signature = HttpSignatures.Parse(received.Signature);
+			Assert.Equal(new[] { "(request-target)", "host", "date", "digest", "collection-synchronization" }, signature.Headers);
+			var signingString = $"(request-target): post /inbox\nhost: {received.Headers["Host"]}\ndate: {received.Headers["Date"]}\ndigest: {received.Headers["Digest"]}\n"
+				+ $"collection-synchronization: {received.Headers[FollowersSynchronization.Header]}";
+			using var key = RSA.Create();
+			key.ImportFromPem(alice.PublicKeyPem);
+			Assert.True(key.VerifyData(Encoding.UTF8.GetBytes(signingString), signature.Signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1));
+		}
+
+		static string Value(HttpRequestRecord received, string name)
+		{
+			var values = received.Headers[FollowersSynchronization.Header].Split(',', StringSplitOptions.TrimEntries)
+				.Select(p => p.Split('=', 2)).ToDictionary(p => p[0], p => p[1].Trim('"'));
+			return values[name];
+		}
+
+		[Fact]
+		public async Task A_delivery_that_is_not_for_followers_carries_none()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var recipient = new RemoteActor(_harness.Peer, "recipient");
+			await _harness.FollowedBy(alice, recipient);
+			_harness.Peer.Answer("/inbox", 202);
+
+			var received = await Delivered(alice, _harness.Peer.A + "/inbox", Create(alice, recipient.Id));
+
+			Assert.False(received.Headers.ContainsKey(FollowersSynchronization.Header));
+			Assert.DoesNotContain("collection-synchronization", HttpSignatures.Parse(received.Signature).Headers);
+		}
+
+		// Mastodon undoes a follow it never knew of with the same id each time ({actor}#follows//undo): when it comes again,
+		// after a new follow, it ends that one too; a copy of it, with nothing to end, stays a copy
+		[Fact]
+		public async Task An_undo_of_a_follow_sent_again_after_a_new_follow_ends_that_one_too()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var undo = new JsonObject
+			{
+				["id"] = bob.Id + "#follows//undo", ["type"] = "Undo", ["actor"] = bob.Id,
+				["object"] = new JsonObject { ["id"] = bob.Id + "#follows/", ["type"] = "Follow", ["actor"] = bob.Id, ["object"] = alice.Uri }
+			};
+			Task<bool> Follows() => DB.Default.Find<Follower>().Match(f => f.LocalActorId == alice.Id && f.ActorURI == bob.Id).ExecuteAnyAsync(Token);
+
+			await _harness.FollowedBy(alice, bob);
+			await _harness.Deliver(bob, "/human-centipede", undo.DeepClone());
+			Assert.False(await Follows());
+
+			await _harness.FollowedBy(alice, bob);
+			await _harness.Deliver(bob, "/human-centipede", undo.DeepClone());
+			Assert.False(await Follows());
+
+			Assert.Equal("duplicate", (await _harness.Deliver(bob, "/human-centipede", undo.DeepClone())).Reason);
+		}
+
+		// received: bob's delivery claims a digest of his followers here, and lists them at his own synchronisation URL
+		async Task Claimed(RemoteActor bob, string digest, params string[] listed)
+		{
+			var path = new Uri(bob.Id).AbsolutePath + "/followers/sync";
+			_harness.Peer.Serve(path, new JsonObject
+			{
+				["id"] = bob.Id + "/followers/sync", ["type"] = "OrderedCollection",
+				["orderedItems"] = new JsonArray(listed.Select(l => (JsonNode)l).ToArray())
+			}.ToJsonString());
+			var note = $"{bob.Id}/notes/{Guid.NewGuid():N}";
+			var request = bob.Post(Harness.Host, "/human-centipede", new JsonObject
+			{
+				["id"] = note + "/activity", ["type"] = "Create", ["actor"] = bob.Id, ["to"] = new JsonArray(bob.Id + "/followers"),
+				["object"] = new JsonObject { ["id"] = note, ["type"] = "Note", ["attributedTo"] = bob.Id, ["to"] = new JsonArray(bob.Id + "/followers"), ["content"] = "hi" }
+			});
+			request.Headers[FollowersSynchronization.Header] = $"collectionId=\"{bob.Id}/followers\", url=\"{bob.Id}/followers/sync\", digest=\"{digest}\"";
+			await _harness.Receiver.Receive(request, default, Token);
+			var job = await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.SynchronizeFollowing && j.State == JobState.Pending && j.Payload.Contains(bob.Id))
+				.ExecuteSingleAsync(Token);
+			var handler = new FollowingSynchronization(_harness.Db, _harness.Local, _harness.Remote, _harness.Follows, _harness.Delivery);
+			Assert.Equal(JobResult.Done, (await handler.Handle(job, Token)).Result);
+		}
+
+		async Task<Following> Follows(LocalActor persona, RemoteActor bob, FollowState state)
+		{
+			var following = new Following
+			{
+				AvatarId = persona.Id, TargetActorURI = bob.Id, TargetInboxURL = bob.Id + "/inbox", State = state, FollowActivityURI = persona.ActivityUri($"follow-{Guid.NewGuid():N}")
+			};
+			await DB.Default.SaveAsync(following, Token);
+			return following;
+		}
+
+		Task<Following> Following(LocalActor persona, RemoteActor bob) =>
+			DB.Default.Find<Following>().Match(f => f.AvatarId == persona.Id && f.TargetActorURI == bob.Id).ExecuteFirstAsync(Token);
+
+		[Fact]
+		public async Task A_claim_that_differs_is_mended_from_the_accounts_own_list()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (_, carol) = await _harness.Persona("carol");
+			var (_, dave) = await _harness.Persona("dave");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			await Follows(alice, bob, FollowState.Accepted);
+			await Follows(carol, bob, FollowState.Requested);
+
+			await Claimed(bob, FollowersSynchronization.Digest([carol.Uri, dave.Uri]), carol.Uri, dave.Uri);
+
+			Assert.Null(await Following(alice, bob));
+			Assert.Equal(FollowState.Accepted, (await Following(carol, bob)).State);
+			var undos = (await _harness.Outgoing(bob.Id + "/inbox")).Where(a => a["type"]!.GetValue<string>() == "Undo").ToList();
+			Assert.Equal(new[] { alice.Uri, dave.Uri }.Order(), undos.Select(u => u["actor"]!.GetValue<string>()).Order());
+			var daves = Assert.Single(undos, u => u["actor"]!.GetValue<string>() == dave.Uri);
+			Assert.Equal(("Follow", bob.Id), (daves["object"]!["type"]!.GetValue<string>(), daves["object"]!["object"]!.GetValue<string>()));
+		}
+
+		[Fact]
+		public async Task A_list_the_claim_does_not_describe_ends_no_follow()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			await Follows(alice, bob, FollowState.Accepted);
+
+			await Claimed(bob, FollowersSynchronization.Digest(["https://privapub.test/peasants/someone"]));
+
+			Assert.Equal(FollowState.Accepted, (await Following(alice, bob)).State);
+		}
+
+		[Fact]
+		public async Task A_claim_that_agrees_reads_nothing()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			await Follows(alice, bob, FollowState.Accepted);
+
+			await Claimed(bob, FollowersSynchronization.Digest([alice.Uri]));
+
+			Assert.DoesNotContain(_harness.Peer.Requests, r => r.Path.EndsWith("/followers/sync"));
+			Assert.Equal(FollowState.Accepted, (await Following(alice, bob)).State);
+		}
+	}
+
+	[Trait("Category", "Integration")]
+	public sealed class RollCallTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		HttpClient _client;
+		Peer _peer;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_client = _host.Client();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			_client?.Dispose();
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		static string[] Items(JsonObject collection) => collection["orderedItems"]!.AsArray().Select(i => i!.GetValue<string>()).ToArray();
+
+		[Fact]
+		public async Task The_roll_call_lists_the_followers_on_the_signing_server_and_asks_for_a_signature()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var persona = await _host.Persona(await _host.SignUp(), "rollcall");
+			var near = new RemoteActor(_peer, "near");
+			var server = new RemoteActor(_peer, "instance", type: "Application");
+			var far = new RemoteActor(_peer, "far", _peer.B);
+			foreach (var follower in new[] { near, far })
+				await DB.Default.SaveAsync(new Follower
+				{
+					LocalActorId = persona.Id, LocalActorKind = LocalActorKind.Person, ActorURI = follower.Id, InboxURL = follower.Id + "/inbox"
+				}, token);
+			var path = $"/peasants/{persona.UserName}/groupies/roll-call";
+
+			var asServer = await _client.Fetch(server.SignedGet(path));
+			var asFar = await _client.Fetch(far.SignedGet(path));
+
+			Assert.Equal(HttpStatusCode.OK, asServer.Status);
+			Assert.Equal(persona.ActorUri() + "/groupies/roll-call", asServer.Json["id"]!.GetValue<string>());
+			Assert.Equal(new[] { near.Id }, Items(asServer.Json));
+			Assert.Equal(new[] { far.Id }, Items(asFar.Json));
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _client.Fetch(path)).Status);
+		}
+	}
+}

PrivaPub.Tests/Federation/FormerRepresentationsTests.cs

@@ -0,0 +1,97 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// Pleroma's and Akkoma's edited posts carry their earlier versions (formerRepresentations): a post first met after its
+	// edits has its history, and an edit tells the ones missed in between
+	[Trait("Category", "Integration")]
+	public sealed class FormerRepresentationsTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+		static readonly DateTime Start = DateTime.UtcNow.AddHours(-1);
+
+		static JsonObject Version(string text, int minutes) => new()
+		{
+			["type"] = "Note", ["content"] = $"<p>{text}</p>", ["published"] = Start.ToString("O"),
+			["updated"] = minutes == 0 ? default : Start.AddMinutes(minutes).ToString("O")
+		};
+
+		async Task<(RemoteActor Carol, JsonObject Note)> Followed(string text, int minutes, params JsonObject[] former)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = carol.Id, State = FollowState.Accepted }, token);
+			var note = Version(text, minutes);
+			note["id"] = $"{Origin(carol)}/objects/{Guid.NewGuid():N}";
+			note["attributedTo"] = carol.Id;
+			note["to"] = new JsonArray(Addressing.Public);
+			note["cc"] = new JsonArray($"{carol.Id}/followers");
+			if (former.Length > 0)
+				note["formerRepresentations"] = new JsonObject { ["type"] = "OrderedCollection", ["totalItems"] = former.Length, ["orderedItems"] = new JsonArray(former) };
+			return (carol, note);
+		}
+
+		Task Deliver(RemoteActor carol, string type, JsonObject note) => _harness.Deliver(carol, "/human-centipede", new JsonObject
+		{
+			["id"] = $"{Origin(carol)}/activities/{Guid.NewGuid():N}", ["type"] = type, ["actor"] = carol.Id,
+			["to"] = new JsonArray(Addressing.Public), ["object"] = note.DeepClone()
+		});
+
+		Task<Post> Stored(JsonObject note) =>
+			DB.Default.Find<Post>().Match(p => p.ObjectURI == note["id"]!.GetValue<string>()).ExecuteSingleAsync(TestContext.Current.CancellationToken);
+
+		[Fact]
+		public async Task A_post_first_met_after_its_edits_has_its_history()
+		{
+			var (carol, note) = await Followed("third", 40, Version("second", 20), Version("first", 0));
+
+			await Deliver(carol, "Create", note);
+
+			var post = await Stored(note);
+			Assert.Equal(["<p>first</p>", "<p>second</p>"], post.Revisions.Select(r => r.ContentHtml));
+			Assert.Equal("<p>third</p>", post.ContentHtml);
+		}
+
+		[Fact]
+		public async Task An_edit_tells_the_versions_missed_in_between()
+		{
+			var (carol, note) = await Followed("first", 0);
+			await Deliver(carol, "Create", note);
+
+			var edited = (JsonObject)note.DeepClone();
+			edited["content"] = "<p>third</p>";
+			edited["updated"] = Start.AddMinutes(40).ToString("O");
+			edited["formerRepresentations"] = new JsonObject
+			{
+				["type"] = "OrderedCollection", ["totalItems"] = 2, ["orderedItems"] = new JsonArray(Version("second", 20), Version("first", 0))
+			};
+			await Deliver(carol, "Update", edited);
+
+			var post = await Stored(note);
+			Assert.Equal(["<p>first</p>", "<p>second</p>"], post.Revisions.Select(r => r.ContentHtml));
+			Assert.Equal("<p>third</p>", post.ContentHtml);
+		}
+	}
+}

PrivaPub.Tests/Federation/ForwardedTests.cs

@@ -0,0 +1,167 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// Inbox forwarding: a thread's server passes on the activities in it, signed with its own key (Mastodon the replies to
+	// its accounts' posts and their deletions, Friendica everything in its threads). They used to be refused with 401.
+	[Trait("Category", "Integration")]
+	public sealed class ForwardedTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		PrivaPub.Models.Statistics.InteractionEvent Processed(string activity) => _harness.Ledger.Of("in").Last(e => e.Activity == activity);
+
+		PrivaPub.Models.Statistics.InteractionEvent Received(string activity) => _harness.Ledger.Of("recv").Last(e => e.Activity == activity);
+
+		Task<Post> Stored(string objectUri) =>
+			DB.Default.Find<Post>().Match(p => p.ObjectURI == objectUri).ExecuteFirstAsync(TestContext.Current.CancellationToken);
+
+		// alice follows the thread's author (on its own server), whose post she holds; bob, elsewhere, replies to it
+		async Task<(RemoteActor Owner, RemoteActor Bob, JsonObject Reply)> Thread()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var owner = new RemoteActor(_harness.Peer, "owner", _harness.Peer.B);
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			await Follows(alice.Id, owner);
+			var post = PublicNote(owner, "<p>the thread</p>");
+			await _harness.Deliver(owner, "/human-centipede", Create(owner, post));
+			Assert.NotNull(await Stored(IdOf(post)));
+
+			var reply = PublicNote(bob, "<p>bob's reply as he wrote it</p>", owner.Id);
+			reply["inReplyTo"] = IdOf(post);
+			_harness.Peer.Serve(new Uri(IdOf(reply)).AbsolutePath, reply.ToJsonString());
+			return (owner, bob, reply);
+		}
+
+		[Fact]
+		public async Task A_reply_the_threads_server_forwards_is_kept_as_its_author_wrote_it()
+		{
+			var (owner, bob, reply) = await Thread();
+			var claimed = (JsonObject)reply.DeepClone();
+			claimed["content"] = "<p>what the forwarder says bob wrote</p>";
+
+			var result = await _harness.Deliver(owner, "/human-centipede", Create(bob, claimed));
+
+			Assert.Equal((202, "forwarded"), (result.StatusCode, result.Reason));
+			var stored = await Stored(IdOf(reply));
+			Assert.NotNull(stored);
+			Assert.Equal(bob.Id, stored.ActorURI);
+			Assert.Contains("as he wrote it", stored.ContentHtml);
+			Assert.Equal(("accepted", "stored"), (Processed("Create").Outcome, Processed("Create").Reason));
+			Assert.True((await DB.Default.Find<PrivaPub.Models.Federation.ObjectRecord>().Match(r => r.ObjectURI == IdOf(reply)).ExecuteFirstAsync(TestContext.Current.CancellationToken)).Refetched);
+		}
+
+		[Fact]
+		public async Task A_forwarded_edit_applies_the_post_as_its_origin_has_it_now()
+		{
+			var (owner, bob, reply) = await Thread();
+			await _harness.Deliver(owner, "/human-centipede", Create(bob, reply));
+			var edited = (JsonObject)reply.DeepClone();
+			edited["content"] = "<p>bob's reply, edited</p>";
+			edited["updated"] = DateTime.UtcNow.AddMinutes(1).ToString("O");
+			_harness.Peer.Serve(new Uri(IdOf(reply)).AbsolutePath, edited.ToJsonString());
+			var claimed = (JsonObject)edited.DeepClone();
+			claimed["content"] = "<p>an edit bob never made</p>";
+
+			await _harness.Deliver(owner, "/human-centipede", Activity(bob, "Update", claimed));
+
+			Assert.Contains("bob's reply, edited", (await Stored(IdOf(reply))).ContentHtml);
+		}
+
+		[Fact]
+		public async Task A_forwarded_deletion_waits_for_the_origin_to_say_the_post_is_gone()
+		{
+			var (owner, bob, reply) = await Thread();
+			await _harness.Deliver(owner, "/human-centipede", Create(bob, reply));
+
+			await _harness.Deliver(owner, "/human-centipede", Activity(bob, "Delete", JsonValue.Create(IdOf(reply))!));
+			Assert.Equal(("dropped", "forwarded-not-gone"), (Processed("Delete").Outcome, Processed("Delete").Reason));
+			Assert.NotNull(await Stored(IdOf(reply)));
+
+			_harness.Peer.Answer(new Uri(IdOf(reply)).AbsolutePath, 410);
+			await _harness.Deliver(owner, "/human-centipede", Activity(bob, "Delete", JsonValue.Create(IdOf(reply))!));
+			Assert.Null(await Stored(IdOf(reply)));
+		}
+
+		// the origin answers 404 for a followers-only post to our instance actor too: only its author's server says it is gone
+		[Fact]
+		public async Task A_forwarded_deletion_of_a_followers_only_post_is_left_to_its_author()
+		{
+			var (owner, bob, reply) = await Thread();
+			await _harness.Deliver(owner, "/human-centipede", Create(bob, reply));
+			await DB.Default.Update<Post>().Match(p => p.ObjectURI == IdOf(reply)).Modify(p => p.Visibility, PostVisibility.FollowersOnly).ExecuteAsync(TestContext.Current.CancellationToken);
+			_harness.Peer.Answer(new Uri(IdOf(reply)).AbsolutePath, 404);
+
+			await _harness.Deliver(owner, "/human-centipede", Activity(bob, "Delete", JsonValue.Create(IdOf(reply))!));
+
+			Assert.Equal(("dropped", "forwarded-private"), (Processed("Delete").Outcome, Processed("Delete").Reason));
+			Assert.NotNull(await Stored(IdOf(reply)));
+		}
+
+		// a forwarded copy is kept apart from the author's own delivery, which carries what the copy could not
+		[Fact]
+		public async Task The_authors_own_delivery_is_still_taken_after_a_forwarded_copy_that_failed()
+		{
+			var (owner, bob, reply) = await Thread();
+			_harness.Peer.Answer(new Uri(IdOf(reply)).AbsolutePath, 404);
+			var create = Create(bob, reply);
+
+			await _harness.Deliver(owner, "/human-centipede", create);
+			Assert.Null(await Stored(IdOf(reply)));
+
+			var direct = await _harness.Deliver(bob, "/human-centipede", create);
+			Assert.Equal("queued", direct.Reason);
+			Assert.NotNull(await Stored(IdOf(reply)));
+		}
+
+		// what cannot be checked against its origin (a vote, a follow, someone else's post) is let go, answered 202: a 401
+		// tells the forwarder its signature failed
+		[Fact]
+		public async Task What_a_forwarder_cannot_vouch_for_is_let_go_without_an_error()
+		{
+			var (owner, bob, reply) = await Thread();
+			var like = new JsonObject { ["id"] = NewId(bob, "likes"), ["type"] = "Like", ["actor"] = bob.Id, ["object"] = IdOf(reply) };
+
+			var result = await _harness.Deliver(owner, "/human-centipede", like);
+			Assert.Equal((202, "forwarded-ignored"), (result.StatusCode, result.Reason));
+			Assert.Equal("dropped", Received("Like").Outcome);
+
+			var onTheForwardersServer = PublicNote(owner, "<p>a post of the forwarder's</p>");
+			onTheForwardersServer["attributedTo"] = bob.Id;
+			result = await _harness.Deliver(owner, "/human-centipede", Create(bob, onTheForwardersServer));
+			Assert.Equal((202, "forwarded-ignored"), (result.StatusCode, result.Reason));
+			Assert.Null(await Stored(IdOf(onTheForwardersServer)));
+
+			// our own, coming back from a thread on another server
+			var (_, carol) = await _harness.Persona("carol");
+			var ours = new JsonObject
+			{
+				["id"] = carol.Uri + "/grunts/create-" + Guid.NewGuid().ToString("N"),
+				["type"] = "Create",
+				["actor"] = carol.Uri,
+				["object"] = new JsonObject { ["id"] = carol.Uri + "/scribbles/" + Guid.NewGuid().ToString("N"), ["type"] = "Note", ["attributedTo"] = carol.Uri }
+			};
+			result = await _harness.Deliver(owner, "/human-centipede", ours);
+			Assert.Equal((202, "forwarded-ignored"), (result.StatusCode, result.Reason));
+		}
+	}
+}

PrivaPub.Tests/Federation/GroupTests.cs

@@ -90,6 +90,28 @@ namespace PrivaPub.Tests.Federation
 			Assert.Contains(announces, a => a["object"] is JsonValue);
 		}
 
+		[Fact]
+		public async Task A_comment_in_a_community_is_announced_activity_and_object_too()
+		{
+			var (_, owner) = await _harness.Persona("owner");
+			var (_, community) = await Group(GroupKind.Community, PostingPolicy.Followers, owner.Id);
+			var lemmy = new RemoteActor(_harness.Peer, "lemmy");
+			var akkoma = new RemoteActor(_harness.Peer, "akkoma");
+			await _harness.FollowedBy(community, lemmy);
+			await _harness.FollowedBy(community, akkoma);
+			var thread = Create(lemmy, new[] { community.Uri, Addressing.Public }, community.Uri);
+			await _harness.Deliver(lemmy, "/human-centipede", thread);
+			var comment = Create(lemmy, new[] { community.Uri, Addressing.Public }, community.Uri);
+			comment["object"]!["inReplyTo"] = thread["object"]!["id"]!.GetValue<string>();
+
+			await _harness.Deliver(lemmy, "/human-centipede", comment);
+
+			var commentId = comment["object"]!["id"]!.GetValue<string>();
+			var announces = (await _harness.Outgoing(akkoma.SharedInbox)).Where(a => a["actor"]!.GetValue<string>() == community.Uri).ToList();
+			Assert.Contains(announces, a => a["object"] is JsonObject inner && inner["object"]?["id"]?.GetValue<string>() == commentId);
+			Assert.Contains(announces, a => a["object"] is JsonValue bare && bare.GetValue<string>() == commentId);
+		}
+
 		[Fact]
 		public async Task An_open_community_takes_posts_from_anyone()
 		{
@@ -103,6 +125,21 @@ namespace PrivaPub.Tests.Federation
 			Assert.True(await DB.Default.Find<Post>().Match(p => p.GroupId == community.Id && p.ActorURI == stranger.Id).ExecuteAnyAsync(token));
 		}
 
+		// Lemmy keeps its user's post pending until the community announces it back, whether anyone there follows the
+		// community or not
+		[Fact]
+		public async Task A_post_into_a_community_is_announced_back_to_its_authors_server_though_nobody_there_follows_it()
+		{
+			var (_, owner) = await _harness.Persona("owner");
+			var (_, community) = await Group(GroupKind.Community, PostingPolicy.Anyone, owner.Id);
+			var stranger = new RemoteActor(_harness.Peer, "stranger", sharedInbox: true);
+
+			await _harness.Deliver(stranger, "/human-centipede", Create(stranger, new[] { community.Uri, Addressing.Public }, community.Uri));
+
+			var announces = (await _harness.Outgoing(stranger.SharedInbox)).Where(a => a["actor"]!.GetValue<string>() == community.Uri).ToList();
+			Assert.Contains(announces, a => a["object"] is JsonObject inner && inner["type"]!.GetValue<string>() == "Create");
+		}
+
 		[Fact]
 		public async Task Mentioning_a_community_posts_into_it_as_a_titled_page()
 		{
@@ -195,11 +232,13 @@ namespace PrivaPub.Tests.Federation
 			entity.Members.Add(new GroupMember { AvatarId = bob.Id });
 			await DB.Default.SaveAsync(entity, token);
 			var outsider = new RemoteActor(_harness.Peer, "asked");
-			await _harness.Remote.GetActor(outsider.Id, refresh: false, token);
+			var outsiderAccount = await _harness.Remote.GetActor(outsider.Id, refresh: false, token);
 			var asksFirst = new Post
 			{
 				ObjectURI = $"{Origin(outsider)}/notes/{Guid.NewGuid():N}",
 				ActorURI = outsider.Id,
+				GroupUserId = outsiderAccount.ID,
+				AuthorAccountId = outsiderAccount.ID,
 				IsFederatedCopy = true,
 				Visibility = PostVisibility.Public,
 				ContentHtml = "<p>ask me first</p>",

PrivaPub.Tests/Federation/HttpSignaturesTests.cs

@@ -101,6 +101,33 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal("the signature has expired",
 				Check(MastodonRequest(extra: $",expires=\"{Now.AddMinutes(-20).ToUnixTimeSeconds()}\"")));
 
+		// hs2019 leaves the hash to the key: some sign RSA with SHA-512, which rsa-sha256 does not allow; and a SHA-512 digest
+		[Fact]
+		public void Accepts_hs2019_hashed_with_sha512_and_a_sha512_digest()
+		{
+			var context = new DefaultHttpContext();
+			context.Request.Method = "POST";
+			context.Request.Host = new HostString(Host);
+			context.Request.Path = "/peasants/bob/mouth";
+			context.Features.Get<IHttpRequestFeature>().RawTarget = "/peasants/bob/mouth";
+			var date = Now.ToString("r", CultureInfo.InvariantCulture);
+			var digest = "SHA-512=" + Convert.ToBase64String(SHA512.HashData(Body));
+			context.Request.Headers["Date"] = date;
+			context.Request.Headers["Digest"] = digest;
+			var signingString = $"(request-target): post /peasants/bob/mouth\nhost: {Host}\ndate: {date}\ndigest: {digest}";
+			var signature = Convert.ToBase64String(_key.SignData(Encoding.UTF8.GetBytes(signingString), HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1));
+			string Signed(string algorithm) => $"keyId=\"{KeyId}\",algorithm=\"{algorithm}\",headers=\"(request-target) host date digest\",signature=\"{signature}\"";
+
+			context.Request.Headers["Signature"] = Signed("hs2019");
+			var parameters = HttpSignatures.Parse(context.Request.Headers["Signature"].ToString());
+			Assert.Null(HttpSignatures.CheckRequest(context.Request, parameters, Body, Now));
+			Assert.True(HttpSignatures.Verify(PublicKey, HttpSignatures.SigningString(context.Request, parameters), parameters.Signature, parameters.Algorithm));
+
+			context.Request.Headers["Signature"] = Signed("rsa-sha256");
+			parameters = HttpSignatures.Parse(context.Request.Headers["Signature"].ToString());
+			Assert.False(HttpSignatures.Verify(PublicKey, HttpSignatures.SigningString(context.Request, parameters), parameters.Signature, parameters.Algorithm));
+		}
+
 		[Fact]
 		public void Signs_with_the_raw_request_target()
 		{

PrivaPub.Tests/Federation/InboundBlockTests.cs

@@ -0,0 +1,77 @@
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Relationships;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// A remote account's Block of a persona, as Mastodon sends it (the pasture's last Mastodon expected failure, G-0002)
+	[Trait("Category", "Integration")]
+	public sealed class InboundBlockTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+
+		[Fact]
+		public async Task A_block_ends_the_follows_both_ways_hides_the_blocker_and_its_undo_lifts_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await _harness.FollowedBy(alice, carol);
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = carol.Id, State = FollowState.Accepted }, token);
+			var block = new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/blocks/{Guid.NewGuid():N}", ["type"] = "Block", ["actor"] = carol.Id, ["object"] = alice.Uri
+			};
+
+			await _harness.Deliver(carol, $"/peasants/{alice.UserName}/mouth", block);
+
+			Assert.True(await DB.Default.Find<BlockedBy>().Match(b => b.AvatarId == alice.Id && b.ActorURI == carol.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Follower>().Match(f => f.LocalActorId == alice.Id && f.ActorURI == carol.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == carol.Id).ExecuteAnyAsync(token));
+			Assert.Contains(carol.Id, await Hidden.AuthorsHiddenFrom(alice.Id, new[] { carol.Id }, forNotifications: false, token));
+			Assert.Contains(alice.Id, await Hidden.RecipientsHiding(new[] { alice.Id }, carol.Id, token));
+
+			await _harness.Deliver(carol, $"/peasants/{alice.UserName}/mouth", new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/undos/{Guid.NewGuid():N}", ["type"] = "Undo", ["actor"] = carol.Id, ["object"] = block
+			});
+
+			Assert.False(await DB.Default.Find<BlockedBy>().Match(b => b.AvatarId == alice.Id && b.ActorURI == carol.Id).ExecuteAnyAsync(token));
+			Assert.Empty(await Hidden.AuthorsHiddenFrom(alice.Id, new[] { carol.Id }, forNotifications: false, token));
+		}
+
+		[Fact]
+		public async Task A_block_of_someone_who_is_not_ours_is_dropped()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var carol = new RemoteActor(_harness.Peer, "carol");
+
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/blocks/{Guid.NewGuid():N}", ["type"] = "Block", ["actor"] = carol.Id,
+				["object"] = $"{Origin(carol)}/users/somebody-else"
+			});
+
+			Assert.False(await DB.Default.Find<BlockedBy>().Match(b => b.ActorURI == carol.Id).ExecuteAnyAsync(token));
+		}
+	}
+}

PrivaPub.Tests/Federation/InboundRoutingTests.cs

@@ -2,6 +2,7 @@ using MongoDB.Entities;
 
 using PrivaPub.ClientModels.Post;
 using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Group;
 using PrivaPub.Models.Post;
 using PrivaPub.Tests.Support;
 
@@ -106,6 +107,75 @@ namespace PrivaPub.Tests.Federation
 			Assert.NotNull(message.ConversationId);
 		}
 
+		// Mbin addresses its private messages to the recipient's profile page (its `url`), not to the actor
+		[Fact]
+		public async Task A_chat_message_addressed_to_a_personas_profile_page_reaches_the_persona()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var mbin = new RemoteActor(_harness.Peer, "mbuser");
+			var messageId = NewId(mbin, "f/object");
+
+			await _harness.Deliver(mbin, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(mbin, "f/object"), ["type"] = "Create", ["actor"] = mbin.Id, ["to"] = new JsonArray(alice.HtmlUrl), ["cc"] = new JsonArray(),
+				["object"] = new JsonObject
+				{
+					["id"] = messageId, ["type"] = "ChatMessage", ["attributedTo"] = mbin.Id, ["to"] = new JsonArray(alice.HtmlUrl), ["cc"] = new JsonArray(),
+					["content"] = "<p>an answer</p>", ["mediaType"] = "text/html", ["published"] = DateTime.UtcNow.ToString("O")
+				}
+			});
+
+			var message = await DB.Default.Find<Post>().Match(p => p.ObjectURI == messageId).ExecuteFirstAsync(token);
+			Assert.NotNull(message);
+			Assert.Equal(PostVisibility.Direct, message.Visibility);
+			var conversation = await DB.Default.Find<DmGroup>().OneAsync(message.ConversationId, token);
+			Assert.Equal(new[] { alice.Id, mbin.Id }.Order(StringComparer.Ordinal), conversation.Members.Select(m => m.AvatarId).Order(StringComparer.Ordinal));
+		}
+
+		// Lemmy 0.19 and Mbin take a private message only as a ChatMessage: someone who writes to us that way is answered in
+		// kind, anyone else with a Note
+		[Fact]
+		public async Task A_direct_message_answers_in_the_form_its_recipient_writes_in()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var lemmy = new RemoteActor(_harness.Peer, "pm");
+			var mastodon = new RemoteActor(_harness.Peer, "dm");
+			async Task<Post> Received(RemoteActor sender, string type)
+			{
+				var id = NewId(sender, "messages");
+				await _harness.Deliver(sender, "/human-centipede", new JsonObject
+				{
+					["id"] = NewId(sender, "activities/create"), ["type"] = "Create", ["actor"] = sender.Id, ["to"] = new JsonArray(alice.Uri),
+					["object"] = new JsonObject
+					{
+						["id"] = id, ["type"] = type, ["attributedTo"] = sender.Id, ["to"] = new JsonArray(alice.Uri),
+						["content"] = "<p>psst</p>", ["published"] = DateTime.UtcNow.ToString("O")
+					}
+				});
+				return await DB.Default.Find<Post>().Match(p => p.ObjectURI == id).ExecuteSingleAsync(token);
+			}
+			async Task<JsonObject> Answer(RemoteActor to, Post message)
+			{
+				var answer = await _harness.Statuses.Publish(alice, new PrivaPub.Domain.Statuses.StatusDraft
+				{
+					Text = "psst back", Visibility = PostVisibility.Direct, ConversationId = message.ConversationId
+				}, token);
+				Assert.True(answer.Ok, answer.Error);
+				return (JsonObject)(await _harness.Outgoing(to.Id + "/inbox")).Last(a => a["type"]!.GetValue<string>() == "Create")["object"]!;
+			}
+
+			var chat = await Answer(lemmy, await Received(lemmy, "ChatMessage"));
+			var note = await Answer(mastodon, await Received(mastodon, "Note"));
+
+			Assert.Equal("ChatMessage", chat["type"]!.GetValue<string>());
+			Assert.Equal(lemmy.Id, Assert.Single(chat["to"]!.AsArray())!.GetValue<string>());
+			Assert.Null(chat["cc"]);
+			Assert.DoesNotContain("h-card", chat["content"]!.GetValue<string>());
+			Assert.Equal("Note", note["type"]!.GetValue<string>());
+		}
+
 		[Fact]
 		public async Task An_unreachable_key_asks_the_sender_to_retry_instead_of_refusing()
 		{
@@ -121,6 +191,68 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal(300, result.RetryAfterSeconds);
 		}
 
+		// Forte follows a persona by its profile page, as WebFinger names it, rather than by its actor's id; so does its Undo
+		[Fact]
+		public async Task A_follow_of_a_personas_profile_page_follows_the_persona()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var forte = new RemoteActor(_harness.Peer, "forte");
+			var follow = new JsonObject { ["id"] = NewId(forte, "follow"), ["type"] = "Follow", ["actor"] = forte.Id, ["object"] = alice.HtmlUrl };
+
+			Assert.Equal(202, (await _harness.Deliver(forte, "/human-centipede", follow)).StatusCode);
+			Assert.True(await DB.Default.Find<PrivaPub.Models.Federation.Follower>().Match(f => f.LocalActorId == alice.Id && f.ActorURI == forte.Id && f.IsAccepted).ExecuteAnyAsync(token));
+			Assert.Contains(await _harness.Outgoing(forte.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Accept");
+
+			await _harness.Deliver(forte, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(forte, "undo"), ["type"] = "Undo", ["actor"] = forte.Id,
+				["object"] = new JsonObject { ["type"] = "Follow", ["actor"] = forte.Id, ["object"] = alice.HtmlUrl }
+			});
+			Assert.False(await DB.Default.Find<PrivaPub.Models.Federation.Follower>().Match(f => f.LocalActorId == alice.Id && f.ActorURI == forte.Id).ExecuteAnyAsync(token));
+		}
+
+		// Castopod announces an episode with a note that only links to it: the post takes the episode's sound, title and cover
+		[Fact]
+		public async Task A_note_that_only_links_its_authors_episode_carries_the_episodes_sound()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var podcast = new RemoteActor(_harness.Peer, "pod");
+			await DB.Default.SaveAsync(new PrivaPub.Models.Social.Following
+			{
+				AvatarId = alice.Id, TargetActorURI = podcast.Id, TargetInboxURL = podcast.Id + "/inbox", State = PrivaPub.Models.Social.FollowState.Accepted
+			}, token);
+			var origin = new Uri(podcast.Id).GetLeftPart(UriPartial.Authority);
+			var episodePath = $"/episodes/{Guid.NewGuid():N}";
+			_harness.Peer.Serve(episodePath, new JsonObject
+			{
+				["id"] = origin + episodePath, ["type"] = "PodcastEpisode", ["attributedTo"] = podcast.Id, ["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+				["description"] = new JsonObject { ["type"] = "Note", ["content"] = "the meadow", ["mediaType"] = "text/markdown" },
+				["image"] = new JsonObject { ["type"] = "Image", ["url"] = origin + "/cover.png" },
+				["audio"] = new JsonObject
+				{
+					["id"] = origin + "/one.mp3", ["type"] = "Audio", ["name"] = "Episode one", ["duration"] = 4.0,
+					["url"] = new JsonObject { ["href"] = origin + "/one.mp3", ["type"] = "Link", ["mediaType"] = "audio/mpeg" }
+				}
+			}.ToJsonString());
+			var noteId = NewId(podcast, "posts");
+
+			await _harness.Deliver(podcast, "/human-centipede", new JsonObject
+			{
+				["id"] = noteId + "/activity", ["type"] = "Create", ["actor"] = podcast.Id, ["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+				["object"] = new JsonObject
+				{
+					["id"] = noteId, ["type"] = "Note", ["attributedTo"] = podcast.Id, ["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+					["content"] = $"<a href=\"{origin + episodePath}\">Episode one</a><br/>", ["published"] = DateTime.UtcNow.ToString("O")
+				}
+			});
+
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == noteId).ExecuteSingleAsync(token);
+			Assert.Equal(origin + "/one.mp3", Assert.Single(post.Media).RemoteURL);
+			Assert.Equal(("Episode one", origin + "/cover.png", 4.0), (post.Title, post.CoverURL, post.Audio.DurationSeconds));
+		}
+
 		[Fact]
 		public async Task A_join_of_a_local_post_is_answered_with_ignore()
 		{

PrivaPub.Tests/Federation/InboxGapTests.cs

@@ -42,6 +42,204 @@ namespace PrivaPub.Tests.Federation
 
 		PrivaPub.Models.Statistics.InteractionEvent Processed(string activity) => _harness.Ledger.Of("in").Last(e => e.Activity == activity);
 
+		// a follow request nobody answers is sent again after 15 minutes, an hour, 6 hours... (Lemmy 1.0 lost the Accept of a
+		// follow it took before it started sending to us, and the community's posts were refused as not followed)
+		[Fact]
+		public async Task A_follow_request_nobody_answers_is_sent_again_with_a_growing_pause_until_it_is()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var quiet = new RemoteActor(_harness.Peer, "quiet");
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = quiet.Id }, token);
+			var following = await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == quiet.Id).ExecuteSingleAsync(token);
+			async Task<int> Follows() => (await _harness.Outgoing(quiet.Id + "/inbox")).Count(a => a["type"]!.GetValue<string>() == "Follow");
+			var made = following.CreatedAt;
+			Assert.Equal(1, await Follows());
+
+			// (the store is shared with other tests' requests: what this one got is counted on its own inbox)
+			async Task<int> After(TimeSpan wait)
+			{
+				var before = await Follows();
+				await _harness.Follows.ResendPending(made + wait, token);
+				return await Follows() - before;
+			}
+			Assert.Equal(0, await After(TimeSpan.FromMinutes(10)));
+			Assert.Equal(1, await After(TimeSpan.FromMinutes(16)));
+			Assert.Equal(0, await After(TimeSpan.FromMinutes(30)));
+			Assert.Equal(1, await After(TimeSpan.FromMinutes(77)));
+			Assert.Equal(3, await Follows());
+			// each one again under its own id (Lemmy never answers an id it has seen), and an answer naming it counts
+			var sentIds = (await _harness.Outgoing(quiet.Id + "/inbox")).Select(a => a["id"]!.GetValue<string>()).ToList();
+			Assert.Equal(new[] { following.FollowActivityURI, following.FollowActivityURI + "-again-1", following.FollowActivityURI + "-again-2" }, sentIds);
+
+			// a request older than the count is sent again too; an answered one never
+			await DB.Default.Update<Following>().MatchID(following.ID).Modify(b => b.Unset(f => f.Resent)).Modify(b => b.Unset(f => f.ResentAt)).ExecuteAsync(token);
+			Assert.Equal(1, await After(TimeSpan.FromDays(1)));
+			await _harness.Deliver(quiet, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(quiet, "accepts"), ["type"] = "Accept", ["actor"] = quiet.Id, ["object"] = following.FollowActivityURI + "-again-2"
+			});
+			Assert.Equal(FollowState.Accepted, (await DB.Default.Find<Following>().OneAsync(following.ID, token)).State);
+			Assert.Equal(0, await After(TimeSpan.FromDays(30)));
+		}
+
+		// Pixelfed names our post by its page (/@name/<id>, the post's url) in its Like, Announce and their Undo: the post is
+		// found the same as by its id
+		// Friendica's activity ids are uniqid(), a prefix and the microsecond: two of its processes answering two follows at
+		// once gave both Accepts one id, and the second was dropped as a copy of the first, leaving that follow pending
+		[Fact]
+		public async Task Two_activities_a_server_gave_one_id_are_both_taken_and_a_true_copy_once()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var dario = new RemoteActor(_harness.Peer, "dario");
+			var jun = new RemoteActor(_harness.Peer, "jun");
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = dario.Id }, token);
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = jun.Id }, token);
+			Task<Following> Of(RemoteActor target) =>
+				DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == target.Id).ExecuteSingleAsync(token);
+			async Task<JsonObject> Accept(RemoteActor by, string id) => new()
+			{
+				["id"] = id,
+				["type"] = "Accept",
+				["actor"] = by.Id,
+				["object"] = new JsonObject { ["id"] = (await Of(by)).FollowActivityURI, ["type"] = "Follow", ["actor"] = alice.Uri, ["object"] = by.Id }
+			};
+			var shared = NewId(dario, "activity");
+
+			var first = await _harness.Deliver(dario, "/human-centipede", await Accept(dario, shared));
+			var second = await _harness.Deliver(jun, "/human-centipede", await Accept(jun, shared));
+			var copy = await _harness.Deliver(jun, "/human-centipede", await Accept(jun, shared));
+
+			Assert.Equal(("queued", "queued", "duplicate"), (first.Reason, second.Reason, copy.Reason));
+			Assert.Equal(FollowState.Accepted, (await Of(dario)).State);
+			Assert.Equal(FollowState.Accepted, (await Of(jun)).State);
+		}
+
+		// Mobilizon: the organiser creates, edits and deletes an event attributed to the group, which announces it. They used
+		// to be refused as misattributed (400), so the edit was lost and the deletion left the event in place
+		[Fact]
+		public async Task An_event_its_organiser_edits_and_deletes_for_a_group_on_the_same_server_follows_that_server()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var group = new RemoteActor(_harness.Peer, "group", type: "Group");
+			var organiser = new RemoteActor(_harness.Peer, "organiser");
+			await Follows(alice.Id, group);
+			var path = $"/events/{Guid.NewGuid():N}";
+			JsonObject Event(string name) => new()
+			{
+				["id"] = _harness.Peer.A + path, ["type"] = "Event", ["name"] = name, ["content"] = "<p>bring bread</p>",
+				["attributedTo"] = group.Id, ["actor"] = organiser.Id, ["startTime"] = "2026-10-08T18:00:00Z",
+				["to"] = new JsonArray(PrivaPub.Federation.Objects.Addressing.Public), ["cc"] = new JsonArray(group.Id + "/followers")
+			};
+			_harness.Peer.Serve(path, Event("A picnic").ToJsonString());
+			Task<Post> Stored() => DB.Default.Find<Post>().Match(p => p.ObjectURI == _harness.Peer.A + path).ExecuteFirstAsync(token);
+
+			var created = await _harness.Deliver(organiser, "/human-centipede", Create(organiser, Event("A picnic")));
+			Assert.Equal(202, created.StatusCode);
+			Assert.Equal(group.Id, (await Stored()).ActorURI);
+
+			var moved = Event("A picnic, moved indoors");
+			moved["updated"] = DateTime.UtcNow.AddMinutes(1).ToString("O");
+			_harness.Peer.Serve(path, moved.ToJsonString());
+			await _harness.Deliver(organiser, "/human-centipede", Activity(organiser, "Update", Event("what the activity claims")));
+			Assert.Equal("A picnic, moved indoors", (await Stored()).Title);
+
+			await _harness.Deliver(organiser, "/human-centipede", Activity(organiser, "Delete", JsonValue.Create(_harness.Peer.A + path)!));
+			Assert.NotNull(await Stored());
+			_harness.Peer.Answer(path, 410);
+			await _harness.Deliver(organiser, "/human-centipede", Activity(organiser, "Delete", JsonValue.Create(_harness.Peer.A + path)!));
+			Assert.Null(await Stored());
+
+			// attributed to someone of another server, it is still refused
+			var elsewhere = new RemoteActor(_harness.Peer, "elsewhere", _harness.Peer.B);
+			var claimed = Event("Someone else's");
+			claimed["id"] = _harness.Peer.A + $"/events/{Guid.NewGuid():N}";
+			claimed["attributedTo"] = elsewhere.Id;
+			Assert.Equal(400, (await _harness.Deliver(organiser, "/human-centipede", Create(organiser, claimed))).StatusCode);
+		}
+
+		// Funkwhale names its Accept after the Follow it answers (`<our Follow's id>/accept`), on our origin, not its own
+		[Fact]
+		public async Task An_answer_named_after_our_follow_is_taken_and_one_naming_someone_elses_is_not()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var channel = new RemoteActor(_harness.Peer, "channel");
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = channel.Id }, token);
+			var following = await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == channel.Id).ExecuteSingleAsync(token);
+
+			var elsewhere = await _harness.Deliver(channel, "/human-centipede", new JsonObject
+			{
+				["id"] = "https://privapub.test/peasants/somebody/accept", ["type"] = "Accept", ["actor"] = channel.Id, ["object"] = following.FollowActivityURI
+			});
+			Assert.Equal(400, elsewhere.StatusCode);
+
+			var named = await _harness.Deliver(channel, "/human-centipede", new JsonObject
+			{
+				["id"] = following.FollowActivityURI + "/accept", ["type"] = "Accept", ["actor"] = channel.Id,
+				["object"] = new JsonObject { ["id"] = following.FollowActivityURI, ["type"] = "Follow", ["actor"] = alice.Uri, ["object"] = channel.Id }
+			});
+			Assert.Equal(202, named.StatusCode);
+			Assert.Equal(FollowState.Accepted, (await DB.Default.Find<Following>().OneAsync(following.ID, token)).State);
+		}
+
+		// Funkwhale's channel deletes its uploads in one Delete, their ids in a list as the object's id (and the Delete has
+		// no id of its own)
+		[Fact]
+		public async Task A_delete_naming_several_objects_removes_each()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var channel = new RemoteActor(_harness.Peer, "channel");
+			await Follows(alice.Id, channel);
+			var first = PublicNote(channel, "<p>a first track</p>");
+			var second = PublicNote(channel, "<p>a second track</p>");
+			await _harness.Deliver(channel, "/human-centipede", Create(channel, first));
+			await _harness.Deliver(channel, "/human-centipede", Create(channel, second));
+			Task<bool> Held(JsonObject note) => DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(note)).ExecuteAnyAsync(token);
+			Assert.True(await Held(first) && await Held(second));
+
+			var result = await _harness.Receiver.Receive(channel.Post(Harness.Host, "/human-centipede", new JsonObject
+			{
+				["type"] = "Delete", ["actor"] = channel.Id,
+				["object"] = new JsonObject { ["id"] = new JsonArray(IdOf(first), IdOf(second)), ["type"] = "Audio" }
+			}), default, token);
+			Assert.Equal(202, result.StatusCode);
+			var listed = IdOf(first);
+			var job = await DB.Default.Find<PrivaPub.Models.Jobs.Job>().Match(j => j.Kind == PrivaPub.Models.Jobs.JobKind.ProcessInbox
+				&& j.State == PrivaPub.Models.Jobs.JobState.Pending && j.Payload.Contains(listed)).Sort(j => j.CreatedAt, MongoDB.Entities.Order.Descending)
+				.ExecuteFirstAsync(token);
+			await _harness.Processor.Handle(job, token);
+
+			Assert.False(await Held(first));
+			Assert.False(await Held(second));
+		}
+
+		[Fact]
+		public async Task A_like_naming_a_post_by_its_page_counts_and_its_undo_too()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var fan = new RemoteActor(_harness.Peer, "fan");
+			var post = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "a picture" }, token)).Post;
+			var page = alice.PostHtmlUrl(post.ID);
+			Assert.NotEqual(post.ObjectURI, page);
+			var like = new JsonObject { ["id"] = NewId(fan, "likes"), ["type"] = "Like", ["actor"] = fan.Id, ["object"] = page };
+
+			await _harness.Deliver(fan, "/human-centipede", like);
+			Assert.Equal("accepted", Processed("Like").Outcome);
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
+			await _harness.Deliver(fan, "/human-centipede", Activity(fan, "Undo", like));
+			Assert.Equal(0, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
+
+			// a page that is no post of ours stays as it is
+			var elsewhere = new JsonObject { ["id"] = NewId(fan, "likes"), ["type"] = "Like", ["actor"] = fan.Id, ["object"] = alice.PostHtmlUrl("000000000000000000000000") };
+			await _harness.Deliver(fan, "/human-centipede", elsewhere);
+			Assert.Equal(("dropped", "unknown-object"), (Processed("Like").Outcome, Processed("Like").Reason));
+		}
+
 		[Fact]
 		public async Task An_actor_update_refreshes_the_account_from_its_origin_even_when_its_updated_is_older()
 		{
@@ -147,7 +345,7 @@ namespace PrivaPub.Tests.Federation
 		}
 
 		[Fact]
-		public async Task A_followed_community_announcing_a_vote_or_its_undo_is_recorded_and_changes_nothing_yet()
+		public async Task A_vote_a_followed_community_relays_counts_and_its_undo_takes_it_back()
 		{
 			var token = TestContext.Current.CancellationToken;
 			var (root, alice) = await _harness.Persona("alice");
@@ -168,20 +366,201 @@ namespace PrivaPub.Tests.Federation
 
 			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", like));
 			var liked = Processed("Announce");
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
 			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Activity(voter, "Undo", like)));
 			var unliked = Processed("Announce");
 			await _harness.Deliver(stranger, "/human-centipede", Activity(stranger, "Announce", like));
 			var unfollowed = Processed("Announce");
 
-			//votes relayed by a community are a documented gap (docs/INTEROP.md, Lemmy: "Announces of activities other than Create")
+			//Lemmy relays its members' votes inside the community's Announce (G-0003): a voter on the community's own server
-			Assert.Equal(("dropped", "unsupported", "Like"), (liked.Outcome, liked.Reason, liked.Object));
+			//is vouched for by it, and the vote is handled as if the voter had sent it; a community nobody follows is ignored
-			Assert.Equal(("dropped", "unsupported", "Undo"), (unliked.Outcome, unliked.Reason, unliked.Object));
+			Assert.Equal("accepted", liked.Outcome);
+			Assert.Equal("accepted", unliked.Outcome);
 			Assert.Equal(("dropped", "not-followed"), (unfollowed.Outcome, unfollowed.Reason));
 			var after = await DB.Default.Find<Post>().OneAsync(post.ID, token);
 			Assert.Equal(0, after.FavouritesCount);
 			Assert.False(await DB.Default.Find<Favourite>().Match(f => f.PostId == post.ID).ExecuteAnyAsync(token));
 		}
 
+		// Lemmy sends a vote to the community alone: a vote on our reply in a thread of a community nobody here follows still
+		// reaches us through it, and only through that community (found by the town's village)
+		[Fact]
+		public async Task A_vote_on_our_reply_in_an_unfollowed_communitys_thread_counts_through_that_community_only()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "cats", type: "Group");
+			var other = new RemoteActor(_harness.Peer, "dogs", type: "Group");
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var voter = new RemoteActor(_harness.Peer, "voter");
+			var page = PublicNote(poster, "<p>a thread</p>", community.Id);
+			page["type"] = "Page";
+			page["name"] = "a thread";
+			page["audience"] = community.Id;
+			_harness.Peer.Serve(new Uri(IdOf(page)).AbsolutePath, page.ToJsonString());
+			var root = await _harness.RemotePosts.StoreContext(IdOf(page), 0, token);
+			Assert.Equal(community.Id, root.AudienceURI);
+			var reply = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "my answer", InReplyTo = root.ID }, token)).Post;
+			var like = new JsonObject { ["id"] = NewId(voter, "likes"), ["type"] = "Like", ["actor"] = voter.Id, ["object"] = reply.ObjectURI };
+
+			await _harness.Deliver(other, "/human-centipede", Activity(other, "Announce", like));
+			Assert.Equal(("dropped", "not-followed"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", like));
+			Assert.Equal("accepted", Processed("Announce").Outcome);
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).FavouritesCount);
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Activity(voter, "Undo", like)));
+			Assert.Equal(0, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).FavouritesCount);
+		}
+
+		// PieFed moves a post to another community, and the community it leaves relays the Move: the post's thread goes with it
+		[Fact]
+		public async Task A_post_moved_to_another_community_takes_its_thread_along()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "cats", type: "Group");
+			var other = new RemoteActor(_harness.Peer, "dogs", type: "Group");
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = community.Id }, token);
+			await DB.Default.Update<Following>().Match(f => f.AvatarId == alice.Id).Modify(f => f.State, FollowState.Accepted).ExecuteAsync(token);
+			async Task<Post> Announced(JsonObject note)
+			{
+				note["audience"] = community.Id;
+				_harness.Peer.Serve(new Uri(IdOf(note)).AbsolutePath, note.ToJsonString());
+				await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Create(poster, note)));
+				return await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(note)).ExecuteSingleAsync(token);
+			}
+			var page = PublicNote(poster, "<p>misplaced</p>", community.Id);
+			page["type"] = "Page";
+			page["name"] = "misplaced";
+			var post = await Announced(page);
+			var comment = PublicNote(poster, "<p>a comment</p>", community.Id);
+			comment["inReplyTo"] = IdOf(page);
+			var answer = await Announced(comment);
+			var move = new JsonObject
+			{
+				["id"] = NewId(poster, "moves"), ["type"] = "Move", ["actor"] = poster.Id, ["object"] = post.ObjectURI, ["origin"] = community.Id, ["target"] = other.Id
+			};
+
+			// only the community it leaves speaks for it
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", new JsonObject
+			{
+				["id"] = NewId(poster, "moves"), ["type"] = "Move", ["actor"] = poster.Id, ["object"] = post.ObjectURI, ["origin"] = other.Id, ["target"] = community.Id
+			}));
+			Assert.Equal(("dropped", "unsupported"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", move));
+			Assert.Equal(("accepted", "moved"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			Assert.Equal(other.Id, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).AudienceURI);
+			Assert.Equal(other.Id, (await DB.Default.Find<Post>().OneAsync(answer.ID, token)).AudienceURI);
+		}
+
+		// Lemmy's moderators lock a community's post and ban members, and the community relays both inside its Announce
+		// (G-0006): a locked post takes no reply, a banned persona posts nothing there, until the Undo
+		[Fact]
+		public async Task A_community_locks_a_post_and_bans_a_persona_until_it_undoes_either()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "cats", type: "Group");
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var moderator = new RemoteActor(_harness.Peer, "moderator");
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = community.Id }, token);
+			await DB.Default.Update<Following>().Match(f => f.AvatarId == alice.Id).Modify(f => f.State, FollowState.Accepted).ExecuteAsync(token);
+			JsonObject Page(string text, bool commentsEnabled = true)
+			{
+				var page = PublicNote(poster, $"<p>{text}</p>", community.Id);
+				page["type"] = "Page";
+				page["name"] = text;
+				page["audience"] = community.Id;
+				page["commentsEnabled"] = commentsEnabled;
+				_harness.Peer.Serve(new Uri(IdOf(page)).AbsolutePath, page.ToJsonString());
+				return page;
+			}
+			async Task<Post> Announced(JsonObject page)
+			{
+				await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Create(poster, page)));
+				return await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(page)).ExecuteSingleAsync(token);
+			}
+			Task<StatusOutcome> Reply(Post post) => _harness.Statuses.Publish(alice, new StatusDraft { Text = "a reply", InReplyTo = post.ID }, token);
+			var post = await Announced(Page("a thread"));
+			var lockIt = new JsonObject { ["id"] = NewId(moderator, "locks"), ["type"] = "Lock", ["actor"] = moderator.Id, ["object"] = post.ObjectURI };
+
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", lockIt));
+			Assert.Equal(("accepted", "locked"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			var refused = await Reply(post);
+			Assert.Equal((422, "Validation failed: This thread is locked"), (refused.Status, refused.Error));
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Activity(moderator, "Undo", lockIt)));
+			Assert.Null((await DB.Default.Find<Post>().OneAsync(post.ID, token)).LockedAt);
+			Assert.True((await Reply(post)).Ok);
+			// a post its community serves locked arrives locked
+			Assert.NotNull((await Announced(Page("born locked", commentsEnabled: false))).LockedAt);
+
+			var ban = new JsonObject { ["id"] = NewId(moderator, "bans"), ["type"] = "Block", ["actor"] = moderator.Id, ["object"] = alice.Uri, ["target"] = community.Id };
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", ban));
+			Assert.Equal(("accepted", "banned"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			var banned = await Reply(post);
+			Assert.Equal((422, "Validation failed: This community banned you"), (banned.Status, banned.Error));
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Activity(moderator, "Undo", ban)));
+			Assert.Equal(("accepted", "unbanned"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			Assert.True((await Reply(post)).Ok);
+
+			// Lemmy also sends the ban straight to the persona's server, as its moderator's Block: still the community's ban,
+			// never the moderator's own block of the persona
+			var direct = new JsonObject { ["id"] = NewId(moderator, "bans"), ["type"] = "Block", ["actor"] = moderator.Id, ["object"] = alice.Uri, ["target"] = community.Id };
+			await _harness.Deliver(moderator, "/human-centipede", direct);
+			Assert.Equal(("accepted", "banned"), (Processed("Block").Outcome, Processed("Block").Reason));
+			Assert.False(await DB.Default.Find<BlockedBy>().Match(b => b.AvatarId == alice.Id && b.ActorURI == moderator.Id).ExecuteAnyAsync(token));
+			Assert.Equal(422, (await Reply(post)).Status);
+			await _harness.Deliver(moderator, "/human-centipede", Activity(moderator, "Undo", direct));
+			Assert.True((await Reply(post)).Ok);
+
+			var elsewhere = new JsonObject { ["id"] = NewId(moderator, "bans"), ["type"] = "Block", ["actor"] = moderator.Id, ["object"] = poster.Id, ["target"] = community.Id };
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", elsewhere));
+			Assert.Equal(("dropped", "not-ours"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+		}
+
+		// a voter on another server than the community is believed for the community's own posts, as Lemmy trusts it; for
+		// anything else only once its vote is fetched from its own origin
+		[Fact]
+		public async Task A_relayed_vote_from_another_server_counts_on_the_communitys_posts_and_elsewhere_only_once_fetched()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (root, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "cats", type: "Group");
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var voter = new RemoteActor(_harness.Peer, "voter", origin: _harness.Peer.B);
+			var forger = new RemoteActor(_harness.Peer, "forger", origin: _harness.Peer.B);
+			await _harness.Follows.Follow(root, new FollowForm { AvatarId = alice.Id, Target = community.Id }, token);
+			await DB.Default.Update<Following>().Match(f => f.AvatarId == alice.Id).Modify(f => f.State, FollowState.Accepted).ExecuteAsync(token);
+			var page = PublicNote(poster, "<p>a post</p>", community.Id);
+			page["type"] = "Page";
+			page["name"] = "a title";
+			_harness.Peer.Serve(new Uri(IdOf(page)).AbsolutePath, page.ToJsonString());
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", Create(poster, page)));
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(page)).ExecuteSingleAsync(token);
+			var other = await OwnPost(alice, token);
+			var like = new JsonObject { ["id"] = NewId(voter, "likes"), ["type"] = "Like", ["actor"] = voter.Id, ["object"] = post.ObjectURI };
+			var forged = new JsonObject { ["id"] = NewId(forger, "likes"), ["type"] = "Like", ["actor"] = forger.Id, ["object"] = other.ObjectURI };
+
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", like));
+			await _harness.Deliver(community, "/human-centipede", Activity(community, "Announce", forged));
+
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
+			Assert.True(await DB.Default.Find<Favourite>().Match(f => f.PostId == post.ID && f.ActorURI == voter.Id).ExecuteAnyAsync(token));
+			Assert.Equal(("dropped", "fetch-failed"), (Processed("Announce").Outcome, Processed("Announce").Reason));
+			Assert.Equal(0, (await DB.Default.Find<Post>().OneAsync(other.ID, token)).FavouritesCount);
+		}
+
+		// a public post of a persona's own, outside any community
+		static async Task<Post> OwnPost(PrivaPub.Federation.Actors.LocalActor author, CancellationToken token)
+		{
+			var post = new Post { GroupUserId = author.Id, AuthorAccountId = author.Id, Text = "not the community's" };
+			post.ID = (string)post.GenerateNewID();
+			post.ObjectURI = author.PostUri(post.ID);
+			await DB.Default.SaveAsync(post, token);
+			return post;
+		}
+
 		[Fact]
 		public async Task A_locked_persona_holds_a_follow_until_it_decides_and_answers_with_the_original_follow()
 		{

PrivaPub.Tests/Federation/InboxScenarioTests.cs

@@ -171,12 +171,19 @@ namespace PrivaPub.Tests.Federation
 			var token = TestContext.Current.CancellationToken;
 			var alice = await LocalAvatar("alice");
 			var mallory = new RemoteActor(_peer, "mallory");
-			var victim = new RemoteActor(_peer, "victim");
+			var victim = new RemoteActor(_peer, "victim", _peer.B);
 
 			var result = await Deliver(mallory, $"/peasants/{alice.UserName}/mouth", DirectCreate(mallory, alice.Uri, attributedTo: victim.Id));
 
 			Assert.Equal(400, result.StatusCode);
 			Assert.False(await DB.Default.Find<Post>().Match(p => p.ActorURI == victim.Id).ExecuteAnyAsync(token));
+
+			// a colleague on mallory's own server is that server's to vouch for: believed only as the server has it, and
+			// it has no such note
+			var colleague = new RemoteActor(_peer, "colleague");
+			result = await Deliver(mallory, $"/peasants/{alice.UserName}/mouth", DirectCreate(mallory, alice.Uri, attributedTo: colleague.Id));
+			Assert.Equal(202, result.StatusCode);
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ActorURI == colleague.Id).ExecuteAnyAsync(token));
 		}
 
 		[Fact]
@@ -263,6 +270,28 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal(alice.Id, mention.AccountId);
 		}
 
+		// GoToSocial kept a persona in cc after an edit took the @name out, and Akkoma addresses with to[] alone: the persona it
+		// is addressed to sees a followers-only post as a silent mention, which no list shows as a mention (found by the town)
+		[Fact]
+		public async Task A_followers_only_post_addressed_to_a_persona_without_naming_it_is_a_silent_mention()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var alice = await LocalAvatar("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var create = PublicCreate(bob, default, alice.Uri);
+			create["object"]!["to"] = bob.Id + "/followers";
+			create["object"]!["cc"] = alice.Uri;
+
+			await Deliver(bob, "/human-centipede", create);
+
+			var post = await DB.Default.Find<Post>().Match(p => p.ActorURI == bob.Id).ExecuteSingleAsync(token);
+			Assert.Equal(PostVisibility.FollowersOnly, post.Visibility);
+			var mention = Assert.Single(post.Mentions);
+			Assert.True(mention.Silent);
+			Assert.Equal(alice.Id, mention.AccountId);
+			Assert.True(await PrivaPub.Domain.Privacy.VisibilityPolicy.CanSee(post, alice.Id, token));
+		}
+
 		[Fact]
 		public async Task A_suspended_domain_is_dropped_before_its_key_is_fetched()
 		{

PrivaPub.Tests/Federation/IntegrityProofTests.cs

@@ -0,0 +1,175 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Rendering;
+using PrivaPub.Federation.Signing;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.User;
+using PrivaPub.Tests.Support;
+
+using System.Text;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// FEP-8b32 proofs (eddsa-jcs-2022) by a persona's Ed25519 key, which its actor names as a FEP-521a Multikey
+	public sealed class IntegrityProofTests
+	{
+		[Fact]
+		public void Canonical_json_is_rfc_8785s()
+		{
+			// RFC 8785, section 3.2.2
+			var input = JsonNode.Parse("{\"numbers\":[333333333.33333329,1E30,4.50,2e-3,0.000000000000000000000000001],"
+				+ "\"string\":\"\\u20ac$\\u000F\\u000aA'\\u0042\\u0022\\u005c\\\\\\\"\\/\",\"literals\":[null,true,false]}");
+
+			Assert.Equal("{\"literals\":[null,true,false],\"numbers\":[333333333.3333333,1e+30,4.5,0.002,1e-27],\"string\":\"€$\\u000f\\nA'B\\\"\\\\\\\\\\\"/\"}",
+				Jcs.Serialize(input));
+		}
+
+		[Fact]
+		public void Base58_and_multikeys_read_back_what_they_write()
+		{
+			Assert.Equal("2NEpo7TZRRrLZSi2U", IntegrityProofs.Base58(Encoding.ASCII.GetBytes("Hello World!")));
+			Assert.Equal("112", IntegrityProofs.Base58(new byte[] { 0, 0, 1 }));
+			Assert.Equal(new byte[] { 0, 0, 1 }, IntegrityProofs.FromBase58("112"));
+
+			var publicKey = IntegrityProofs.PublicKey(IntegrityProofs.NewSeed());
+			var multikey = IntegrityProofs.Multikey(publicKey);
+			Assert.StartsWith("z6Mk", multikey);
+			Assert.Equal(publicKey, IntegrityProofs.FromMultikey(multikey));
+		}
+
+		[Fact]
+		public void A_proof_verifies_with_its_key_and_with_nothing_changed()
+		{
+			var seed = IntegrityProofs.NewSeed();
+			var activity = new JsonObject
+			{
+				["@context"] = ActivityPubRenderer.Context(), ["id"] = "https://privapub.test/peasants/alice/grunts/1", ["type"] = "Create",
+				["actor"] = "https://privapub.test/peasants/alice", ["object"] = new JsonObject { ["type"] = "Note", ["content"] = "<p>ciao, è così</p>", ["width"] = 4.5 }
+			};
+			activity["proof"] = IntegrityProofs.Create(activity, "https://privapub.test/peasants/alice#ed25519-key", seed, DateTime.UtcNow);
+
+			var delivered = JsonNode.Parse(activity.ToJsonString())!.AsObject();
+			Assert.True(IntegrityProofs.Verify(delivered, IntegrityProofs.PublicKey(seed)));
+			Assert.Equal("assertionMethod", delivered["proof"]!["proofPurpose"]!.GetValue<string>());
+
+			var changed = delivered.DeepClone().AsObject();
+			changed["object"]!["content"] = "<p>something else</p>";
+			Assert.False(IntegrityProofs.Verify(changed, IntegrityProofs.PublicKey(seed)));
+			Assert.False(IntegrityProofs.Verify(delivered, IntegrityProofs.PublicKey(IntegrityProofs.NewSeed())));
+		}
+
+		[Fact]
+		public void A_persona_with_a_key_names_it_as_a_multikey()
+		{
+			var seed = IntegrityProofs.NewSeed();
+			var actor = ActivityPubRenderer.Actor(new LocalActor { Id = "a", UserName = "alice", BaseAddress = Harness.Base, Kind = LocalActorKind.Person, SigningKey = seed });
+			var keyless = ActivityPubRenderer.Actor(new LocalActor { Id = "b", UserName = "bob", BaseAddress = Harness.Base, Kind = LocalActorKind.Person });
+
+			var key = Assert.Single(actor["assertionMethod"]!.AsArray())!;
+			Assert.Equal(($"{Harness.Base}/peasants/alice#ed25519-key", "Multikey", $"{Harness.Base}/peasants/alice"),
+				(key["id"]!.GetValue<string>(), key["type"]!.GetValue<string>(), key["controller"]!.GetValue<string>()));
+			Assert.Equal(IntegrityProofs.PublicKey(seed), IntegrityProofs.FromMultikey(key["publicKeyMultibase"]!.GetValue<string>()));
+			Assert.Null(keyless["assertionMethod"]);
+		}
+	}
+
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class DeliveredProofTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		// what goes to a relay carries the persona's proof, to be forwarded on its strength; what goes to a server directly
+		// does not (Mitra refuses a proof by a key it has not read yet); another's activity passed on never gets ours
+		[Fact]
+		public async Task A_personas_activity_goes_to_a_relay_with_its_proof_and_elsewhere_without()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, persona) = await _harness.Persona("alice");
+			var seed = IntegrityProofs.NewSeed();
+			await DB.Default.Update<Avatar>().MatchID(persona.Id).Modify(a => a.SigningKey, seed).ExecuteAsync(token);
+			var alice = _harness.Local.FromAvatar(await DB.Default.Find<Avatar>().MatchID(persona.Id).ExecuteSingleAsync(token));
+			var relayInbox = $"{_harness.Peer.A}/relay-{Guid.NewGuid():N}/inbox";
+			var serverInbox = _harness.Peer.A + "/proofs/inbox";
+			await DB.Default.SaveAsync(new RelaySubscription
+			{
+				Configured = relayInbox, ActorURI = relayInbox.Replace("/inbox", "/actor"), InboxURL = relayInbox, State = RelayState.Accepted
+			}, token);
+			var own = new JsonObject { ["id"] = alice.ActivityUri(Guid.NewGuid().ToString("N")), ["type"] = "Create", ["actor"] = alice.Uri, ["object"] = new JsonObject { ["type"] = "Note" } };
+			var passedOn = new JsonObject { ["id"] = $"https://elsewhere.example/activities/{Guid.NewGuid():N}", ["type"] = "Create", ["actor"] = "https://elsewhere.example/users/bob" };
+
+			try
+			{
+				await _harness.Delivery.Enqueue(alice, new[] { relayInbox, serverInbox }, own, token);
+				await _harness.Delivery.Enqueue(alice, new[] { relayInbox }, passedOn, token);
+
+				var toRelay = await _harness.Outgoing(relayInbox);
+				var signed = Assert.Single(toRelay, a => a["actor"]!.GetValue<string>() == alice.Uri);
+				Assert.Equal(alice.AssertionKeyId, signed["proof"]!["verificationMethod"]!.GetValue<string>());
+				Assert.True(IntegrityProofs.Verify(signed, IntegrityProofs.PublicKey(seed)));
+				Assert.Null(Assert.Single(toRelay, a => a["actor"]!.GetValue<string>() != alice.Uri)["proof"]);
+				Assert.Null(Assert.Single(await _harness.Outgoing(serverInbox))["proof"]);
+				Assert.Null(own["proof"]);
+			}
+			finally
+			{
+				await DB.Default.DeleteAsync<RelaySubscription>(s => s.InboxURL == relayInbox);
+			}
+		}
+
+		// a post forwarded by another server, which its origin does not serve: taken on its author's proof, never without
+		[Fact]
+		public async Task A_forwarded_post_with_its_authors_proof_is_taken_as_it_came()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var author = new RemoteActor(_harness.Peer, "author", ed25519: true);
+			var forwarder = new RemoteActor(_harness.Peer, "forwarder", _harness.Peer.B);
+			await DB.Default.SaveAsync(new PrivaPub.Models.Social.Following
+			{
+				AvatarId = alice.Id, TargetActorURI = author.Id, TargetInboxURL = author.Id + "/inbox", State = PrivaPub.Models.Social.FollowState.Accepted
+			}, token);
+			JsonObject Create(string text)
+			{
+				var noteId = $"{new Uri(author.Id).GetLeftPart(UriPartial.Authority)}/notes/{Guid.NewGuid():N}";
+				return new JsonObject
+				{
+					["@context"] = "https://www.w3.org/ns/activitystreams", ["id"] = noteId + "/activity", ["type"] = "Create", ["actor"] = author.Id,
+					["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+					["object"] = new JsonObject
+					{
+						["id"] = noteId, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+						["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"), ["published"] = DateTime.UtcNow.ToString("O")
+					}
+				};
+			}
+			var proven = author.Prove(Create("proven"));
+			var tampered = author.Prove(Create("as written"));
+			tampered["object"]!["content"] = "<p>changed on the way</p>";
+			var bare = Create("unproven");
+
+			await _harness.Deliver(forwarder, "/human-centipede", proven);
+			await _harness.Deliver(forwarder, "/human-centipede", tampered);
+			await _harness.Deliver(forwarder, "/human-centipede", bare);
+
+			Task<bool> Held(JsonObject create) => DB.Default.Find<PrivaPub.Models.Post.Post>().Match(p => p.ObjectURI == create["object"]!["id"]!.GetValue<string>()).ExecuteAnyAsync(token);
+			Assert.True(await Held(proven));
+			Assert.False(await Held(tampered));
+			Assert.False(await Held(bare));
+		}
+	}
+}

PrivaPub.Tests/Federation/InteractionPolicyTests.cs

@@ -0,0 +1,284 @@
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// GoToSocial's interaction policies: who may reply to, like and boost a post at once, who must ask its author first, and
+	// who may not
+	[Trait("Category", "Integration")]
+	public sealed class InteractionPolicyTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static JsonObject Rule(params string[] automatic) => Rule(automatic, Array.Empty<string>());
+
+		static JsonObject Rule(string[] automatic, string[] manual) => new()
+		{
+			["automaticApproval"] = new JsonArray(automatic.Select(a => (JsonNode)a).ToArray()),
+			["manualApproval"] = new JsonArray(manual.Select(m => (JsonNode)m).ToArray())
+		};
+
+		// bob's public post, which alice follows bob to see, under the policy given
+		async Task<(PrivaPub.Federation.Actors.LocalActor Alice, RemoteActor Bob, Post Post, RemoteActor Fan)> Posted(JsonObject policy)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var fan = new RemoteActor(_harness.Peer, "fan");
+			await Follows(alice.Id, bob);
+			await _harness.FollowedBy(alice, fan);
+			var note = PublicNote(bob, "<p>a post with rules</p>");
+			note["interactionPolicy"] = policy;
+			await _harness.Deliver(bob, "/human-centipede", Create(bob, note));
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(note)).ExecuteSingleAsync(token);
+			return (alice, bob, post, fan);
+		}
+
+		Task<List<JsonObject>> To(RemoteActor actor) => _harness.Outgoing(actor.Id + "/inbox");
+
+		Task<List<JsonObject>> ToShared(RemoteActor actor) => _harness.Outgoing(actor.SharedInbox);
+
+		JsonObject Authorization(RemoteActor author, string type, string interaction, Post target)
+		{
+			var path = $"/authorizations/{Guid.NewGuid():N}";
+			var stamp = new JsonObject
+			{
+				["id"] = Origin(author) + path, ["type"] = type, ["attributedTo"] = author.Id,
+				["interactingObject"] = interaction, ["interactionTarget"] = target.ObjectURI
+			};
+			_harness.Peer.Serve(path, stamp.ToJsonString());
+			return stamp;
+		}
+
+		[Fact]
+		public async Task A_reply_the_policy_lets_in_at_once_goes_out_as_always_and_one_it_shuts_out_is_refused()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, _) = await Posted(new JsonObject { ["canReply"] = Rule("https://www.w3.org/ns/activitystreams#Public") });
+			var reply = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "an open reply", InReplyTo = post.ID }, token);
+			Assert.Equal(ApprovalState.None, reply.Post.Approval);
+			Assert.Contains(await To(bob), a => a["type"]!.GetValue<string>() == "Create");
+
+			var (carol, dave, shut, _) = await Posted(new JsonObject { ["canReply"] = Rule(new string[0], new string[0]) });
+			var refused = await _harness.Statuses.Publish(carol, new StatusDraft { Text = "a shut-out reply", InReplyTo = shut.ID }, token);
+			Assert.Equal(422, refused.Status);
+		}
+
+		[Fact]
+		public async Task A_reply_its_author_must_approve_is_asked_for_and_goes_out_with_the_authorization_once_given()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, fan) = await Posted(new JsonObject
+			{
+				["canReply"] = Rule(new[] { "https://dummy.invalid/nobody" }, new[] { "https://www.w3.org/ns/activitystreams#Public" })
+			});
+
+			var reply = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "may I?", InReplyTo = post.ID }, token)).Post;
+
+			Assert.Equal(ApprovalState.Pending, reply.Approval);
+			var request = Assert.Single(await To(bob), a => a["type"]!.GetValue<string>() == "ReplyRequest");
+			Assert.Equal(post.ObjectURI, request["object"]!.GetValue<string>());
+			Assert.Equal(reply.ObjectURI, request["instrument"]!["id"]!.GetValue<string>());
+			Assert.DoesNotContain(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+
+			var stamp = Authorization(bob, "ReplyAuthorization", reply.ObjectURI, post);
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(bob, "accepts"), ["type"] = "Accept", ["actor"] = bob.Id,
+				["object"] = new JsonObject { ["type"] = "ReplyRequest", ["id"] = request["id"]!.GetValue<string>() },
+				["result"] = IdOf(stamp)
+			});
+
+			var after = await DB.Default.Find<Post>().OneAsync(reply.ID, token);
+			Assert.Equal((ApprovalState.Accepted, IdOf(stamp)), (after.Approval, after.ApprovalURI));
+			var create = Assert.Single(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+			Assert.Equal(IdOf(stamp), create["object"]!["replyAuthorization"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task A_rejected_reply_stays_ours_alone_and_a_forged_authorization_changes_nothing()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, fan) = await Posted(new JsonObject
+			{
+				["canReply"] = Rule(new[] { "https://dummy.invalid/nobody" }, new[] { "https://www.w3.org/ns/activitystreams#Public" })
+			});
+			var reply = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "may I?", InReplyTo = post.ID }, token)).Post;
+			var request = Assert.Single(await To(bob), a => a["type"]!.GetValue<string>() == "ReplyRequest");
+
+			// an authorization naming another post is no authorization
+			var forged = Authorization(bob, "ReplyAuthorization", reply.ObjectURI, new Post { ObjectURI = "https://elsewhere.invalid/post" });
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(bob, "accepts"), ["type"] = "Accept", ["actor"] = bob.Id, ["object"] = request["id"]!.GetValue<string>(), ["result"] = IdOf(forged)
+			});
+			Assert.Equal(ApprovalState.Pending, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).Approval);
+
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(bob, "rejects"), ["type"] = "Reject", ["actor"] = bob.Id, ["object"] = request["id"]!.GetValue<string>()
+			});
+			Assert.Equal(ApprovalState.Rejected, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).Approval);
+			Assert.DoesNotContain(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+		}
+
+		[Fact]
+		public async Task A_like_and_a_boost_its_author_must_approve_are_asked_for_and_a_shut_out_boost_is_refused()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, fan) = await Posted(new JsonObject
+			{
+				["canLike"] = Rule(new[] { "https://dummy.invalid/nobody" }, new[] { "https://www.w3.org/ns/activitystreams#Public" }),
+				["canAnnounce"] = Rule(new[] { "https://dummy.invalid/nobody" }, new[] { "https://www.w3.org/ns/activitystreams#Public" })
+			});
+
+			await _harness.Statuses.Favourite(alice, post.ID, true, token);
+			var like = await DB.Default.Find<Favourite>().Match(f => f.AccountId == alice.Id && f.PostId == post.ID).ExecuteSingleAsync(token);
+			Assert.Equal(ApprovalState.Pending, like.Approval);
+			var likeRequest = Assert.Single(await To(bob), a => a["type"]!.GetValue<string>() == "LikeRequest");
+			Assert.DoesNotContain(await To(bob), a => a["type"]!.GetValue<string>() == "Like");
+			var stamp = Authorization(bob, "LikeAuthorization", like.ActivityURI, post);
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(bob, "accepts"), ["type"] = "Accept", ["actor"] = bob.Id, ["object"] = likeRequest["id"]!.GetValue<string>(), ["result"] = IdOf(stamp)
+			});
+			Assert.Equal(ApprovalState.Accepted, (await DB.Default.Find<Favourite>().OneAsync(like.ID, token)).Approval);
+			Assert.Equal(IdOf(stamp), Assert.Single(await To(bob), a => a["type"]!.GetValue<string>() == "Like")["likeAuthorization"]!.GetValue<string>());
+
+			var boost = (await _harness.Statuses.Reblog(alice, post.ID, true, PostVisibility.Public, token)).Post;
+			Assert.Equal(ApprovalState.Pending, boost.Approval);
+			var announceRequest = Assert.Single(await _harness.Outgoing(bob.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "AnnounceRequest");
+			Assert.DoesNotContain(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Announce");
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(bob, "rejects"), ["type"] = "Reject", ["actor"] = bob.Id, ["object"] = announceRequest["id"]!.GetValue<string>()
+			});
+			Assert.Equal(ApprovalState.Rejected, (await DB.Default.Find<Post>().OneAsync(boost.ID, token)).Approval);
+
+			var (carol, _, shut, _) = await Posted(new JsonObject { ["canAnnounce"] = Rule(new string[0], new string[0]) });
+			Assert.Equal(422, (await _harness.Statuses.Reblog(carol, shut.ID, true, PostVisibility.Public, token)).Status);
+		}
+
+		// as a third party: a reply bob's policy does not let in at once is shown only with bob's authorization
+		[Fact]
+		public async Task A_reply_to_a_post_that_needs_its_authors_approval_is_kept_only_with_that_approval()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, _) = await Posted(new JsonObject
+			{
+				["canReply"] = Rule(new[] { "https://dummy.invalid/nobody" }, new[] { "https://www.w3.org/ns/activitystreams#Public" })
+			});
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await Follows(alice.Id, carol);
+
+			var unasked = PublicNote(carol, "<p>barging in</p>");
+			unasked["inReplyTo"] = post.ObjectURI;
+			await _harness.Deliver(carol, "/human-centipede", Create(carol, unasked));
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(unasked)).ExecuteAnyAsync(token));
+
+			var asked = PublicNote(carol, "<p>with leave</p>");
+			asked["inReplyTo"] = post.ObjectURI;
+			asked["replyAuthorization"] = IdOf(Authorization(bob, "ReplyAuthorization", IdOf(asked), post));
+			await _harness.Deliver(carol, "/human-centipede", Create(carol, asked));
+			Assert.True(await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(asked)).ExecuteAnyAsync(token));
+		}
+
+		// bob's public post whose replies wait for his approval (FEP-5624's canReply, as PeerTube sets it on a video whose
+		// comments are moderated), which alice follows bob to see
+		async Task<(PrivaPub.Federation.Actors.LocalActor Alice, RemoteActor Bob, Post Post, RemoteActor Fan)> Moderated(JsonNode canReply)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var fan = new RemoteActor(_harness.Peer, "fan");
+			await Follows(alice.Id, bob);
+			await _harness.FollowedBy(alice, fan);
+			var note = PublicNote(bob, "<p>a moderated post</p>");
+			note["canReply"] = canReply;
+			await _harness.Deliver(bob, "/human-centipede", Create(bob, note));
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(note)).ExecuteSingleAsync(token);
+			return (alice, bob, post, fan);
+		}
+
+		Task Answer(RemoteActor from, string type, Post reply, string inReplyTo) => _harness.Deliver(from, "/human-centipede", new JsonObject
+		{
+			["id"] = NewId(from, "approvals"), ["type"] = type, ["actor"] = from.Id, ["object"] = reply.ObjectURI, ["inReplyTo"] = inReplyTo
+		});
+
+		[Fact]
+		public async Task A_reply_its_author_approves_goes_to_that_author_alone_then_out_with_the_approval()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, fan) = await Moderated("https://www.w3.org/ns/activitystreams#Public");
+
+			var reply = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "a comment to approve", InReplyTo = post.ID }, token)).Post;
+
+			Assert.Equal(ApprovalState.Pending, reply.Approval);
+			var asked = Assert.Single(await To(bob), a => a["type"]!.GetValue<string>() == "Create");
+			Assert.Equal(reply.ObjectURI, asked["object"]!["id"]!.GetValue<string>());
+			Assert.DoesNotContain(await To(bob), a => a["type"]!.GetValue<string>() == "ReplyRequest");
+			Assert.DoesNotContain(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+
+			var approval = NewId(bob, "approve-reply");
+			await _harness.Deliver(bob, "/human-centipede", new JsonObject
+			{
+				["id"] = approval, ["type"] = "ApproveReply", ["actor"] = bob.Id, ["object"] = reply.ObjectURI, ["inReplyTo"] = post.ObjectURI
+			});
+
+			var after = await DB.Default.Find<Post>().OneAsync(reply.ID, token);
+			Assert.Equal((ApprovalState.Accepted, approval), (after.Approval, after.ReplyApprovalURI));
+			var create = Assert.Single(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+			Assert.Equal(approval, create["object"]!["replyApproval"]!.GetValue<string>());
+			Assert.Null(create["object"]!["replyAuthorization"]);
+		}
+
+		[Fact]
+		public async Task A_refused_reply_stays_ours_alone_and_an_approval_from_elsewhere_changes_nothing()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, bob, post, fan) = await Moderated("https://www.w3.org/ns/activitystreams#Public");
+			var reply = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "a comment to refuse", InReplyTo = post.ID }, token)).Post;
+
+			// an approval by someone else than the post's author, or naming another post, is no approval
+			await Answer(new RemoteActor(_harness.Peer, "mallory"), "ApproveReply", reply, post.ObjectURI);
+			await Answer(bob, "ApproveReply", reply, "https://elsewhere.invalid/post");
+			Assert.Equal(ApprovalState.Pending, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).Approval);
+
+			await Answer(bob, "RejectReply", reply, post.ObjectURI);
+			Assert.Equal(ApprovalState.Rejected, (await DB.Default.Find<Post>().OneAsync(reply.ID, token)).Approval);
+			Assert.DoesNotContain(await ToShared(fan), a => a["type"]!.GetValue<string>() == "Create");
+		}
+
+		[Fact]
+		public async Task Only_those_its_canReply_names_or_it_mentions_may_reply()
+		{
+			var (alice, _, post, _) = await Moderated(new JsonArray());
+
+			var refused = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "nobody asked me", InReplyTo = post.ID },
+				TestContext.Current.CancellationToken);
+
+			Assert.Equal(422, refused.Status);
+		}
+	}
+}

PrivaPub.Tests/Federation/InteractionTests.cs

@@ -3,8 +3,10 @@ using MongoDB.Entities;
 using PrivaPub.ClientModels.Post;
 using PrivaPub.ClientModels.Social;
 using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Group;
 using PrivaPub.Models.Post;
 using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
 using PrivaPub.Tests.Support;
 
 using System.Text.Json.Nodes;
@@ -74,6 +76,92 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal(0, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
 		}
 
+		// Our followers-only posts are addressed to the followers collection, never to each follower, so a follower is found
+		// among our followers, not in to/cc. The town found every follower's like, reaction and downvote dropped (G-0001).
+		[Fact]
+		public async Task A_follower_likes_reacts_to_and_downvotes_a_followers_only_post()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, post) = await LocalPost("followersonly");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await _harness.FollowedBy(_harness.Local.FromAvatar(await DB.Default.Find<Avatar>().OneAsync(post.GroupUserId, token)), carol);
+
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/likes/{Guid.NewGuid():N}", ["type"] = "Like", ["actor"] = carol.Id, ["object"] = post.ObjectURI
+			});
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/reactions/{Guid.NewGuid():N}", ["type"] = "EmojiReact", ["actor"] = carol.Id, ["object"] = post.ObjectURI,
+				["content"] = "🔥"
+			});
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(carol)}/dislikes/{Guid.NewGuid():N}", ["type"] = "Dislike", ["actor"] = carol.Id, ["object"] = post.ObjectURI
+			});
+
+			// the downvote counts, and takes the place of carol's like (one vote each, as Lemmy votes)
+			var stored = await DB.Default.Find<Post>().OneAsync(post.ID, token);
+			Assert.Equal(0, stored.FavouritesCount);
+			Assert.Equal(1, stored.DownvotesCount);
+			Assert.True(await DB.Default.Find<Reaction>().Match(r => r.PostId == post.ID && r.ActorURI == carol.Id && r.Emoji == "🔥").ExecuteAnyAsync(token));
+		}
+
+		[Fact]
+		public async Task A_vote_turned_the_other_way_replaces_the_first_as_lemmy_sends_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, post) = await LocalPost();
+			var voter = new RemoteActor(_harness.Peer, "voter");
+			var other = new RemoteActor(_harness.Peer, "other");
+			JsonObject Vote(RemoteActor actor, string type) => new()
+			{
+				["id"] = $"{Origin(actor)}/{type.ToLowerInvariant()}s/{Guid.NewGuid():N}", ["type"] = type, ["actor"] = actor.Id, ["object"] = post.ObjectURI
+			};
+
+			await _harness.Deliver(other, "/human-centipede", Vote(other, "Like"));
+			await _harness.Deliver(voter, "/human-centipede", Vote(voter, "Dislike"));
+			await _harness.Deliver(voter, "/human-centipede", Vote(voter, "Like"));
+			var up = await DB.Default.Find<Post>().OneAsync(post.ID, token);
+			Assert.Equal((2, 0), (up.FavouritesCount, up.DownvotesCount));
+
+			await _harness.Deliver(voter, "/human-centipede", Vote(voter, "Dislike"));
+			var down = await DB.Default.Find<Post>().OneAsync(post.ID, token);
+			Assert.Equal((1, 1), (down.FavouritesCount, down.DownvotesCount));
+			Assert.False(await DB.Default.Find<Favourite>().Match(f => f.PostId == post.ID && f.ActorURI == voter.Id).ExecuteAnyAsync(token));
+		}
+
+		[Fact]
+		public async Task A_circle_member_likes_a_circle_post_and_an_outsider_cannot()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			var mallory = new RemoteActor(_harness.Peer, "mallory");
+			var circle = new Group
+			{
+				UserName = $"circle{Guid.NewGuid():N}"[..20], Name = "a circle", Kind = GroupKind.Circle, OwnerAvatarId = alice.Id,
+				Members = { new() { AvatarId = alice.Id }, new() { AvatarId = carol.Id, IsForeign = true } }
+			};
+			await DB.Default.SaveAsync(circle, token);
+			var post = new Post
+			{
+				GroupUserId = alice.Id, AuthorAccountId = alice.Id, GroupId = circle.ID, Visibility = PostVisibility.Circle, Text = "only us",
+				ObjectURI = $"{alice.Uri}/scribbles/{Guid.NewGuid():N}"
+			};
+			await DB.Default.SaveAsync(post, token);
+
+			foreach (var who in new[] { carol, mallory })
+				await _harness.Deliver(who, "/human-centipede", new JsonObject
+				{
+					["id"] = $"{Origin(who)}/likes/{Guid.NewGuid():N}", ["type"] = "Like", ["actor"] = who.Id, ["object"] = post.ObjectURI
+				});
+
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(post.ID, token)).FavouritesCount);
+			Assert.True(await DB.Default.Find<Favourite>().Match(f => f.PostId == post.ID && f.ActorURI == carol.Id).ExecuteAnyAsync(token));
+		}
+
 		[Fact]
 		public async Task A_boost_of_a_local_post_counts_notifies_and_can_be_undone()
 		{

PrivaPub.Tests/Federation/JobHandlerTests.cs

@@ -111,6 +111,235 @@ namespace PrivaPub.Tests.Federation
 			Assert.DoesNotContain(_harness.Peer.Requests, r => r.Path == new Uri(all[2]).AbsolutePath);
 		}
 
+		JsonObject Served(JsonObject document)
+		{
+			_harness.Peer.Serve(new Uri(IdOf(document)).AbsolutePath, document.ToJsonString());
+			return document;
+		}
+
+		static JsonObject Reply(RemoteActor author, string text, JsonObject parent)
+		{
+			var note = PublicNote(author, $"<p>{text}</p>");
+			note["inReplyTo"] = IdOf(parent);
+			return note;
+		}
+
+		static async Task<Post> Held(JsonObject note)
+		{
+			var post = new Post
+			{
+				ObjectURI = IdOf(note), ActorURI = note["attributedTo"]!.GetValue<string>(), IsFederatedCopy = true, Visibility = PostVisibility.Public,
+				ContentHtml = note["content"]!.GetValue<string>()
+			};
+			await DB.Default.SaveAsync(post, TestContext.Current.CancellationToken);
+			return post;
+		}
+
+		// runs the FetchReplies job for the post, and those it queues for this peer's posts, until none is left; how many ran
+		async Task<int> RunReplies(Post first)
+		{
+			var token = TestContext.Current.CancellationToken;
+			var handler = new RepliesJobHandler(_harness.Db, _harness.Remote, _harness.RemotePosts, _harness.Queue);
+			var origin = new Uri(first.ObjectURI).GetLeftPart(UriPartial.Authority);
+			await _harness.Queue.EnqueueMany(new[] { RepliesJobHandler.For(first, 1) }, token);
+			var ran = 0;
+			while (true)
+			{
+				var mine = new List<Job>();
+				foreach (var job in await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.FetchReplies && j.State == JobState.Pending).ExecuteAsync(token))
+				{
+					var post = await DB.Default.Find<Post>().OneAsync(JsonSerializer.Deserialize<RepliesPayload>(job.Payload)!.PostId, token);
+					if (post?.ObjectURI.StartsWith(origin) == true)
+						mine.Add(job);
+				}
+				if (mine.Count == 0)
+					return ran;
+				foreach (var job in mine)
+				{
+					Assert.Equal(JobResult.Done, (await handler.Handle(job, token)).Result);
+					await DB.Default.Update<Job>().MatchID(job.ID).Modify(j => j.State, JobState.Done).ExecuteAsync(token);
+					ran++;
+				}
+			}
+		}
+
+		static async Task<Dictionary<string, Post>> Stored(params JsonObject[] notes)
+		{
+			var uris = notes.Select(IdOf).ToList();
+			return (await DB.Default.Find<Post>().Match(p => uris.Contains(p.ObjectURI)).ExecuteAsync(TestContext.Current.CancellationToken))
+				.ToDictionary(p => p.ObjectURI);
+		}
+
+		[Fact]
+		public async Task A_threads_replies_are_read_from_their_servers_two_levels_down_and_only_public_ones_kept()
+		{
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var answerer = new RemoteActor(_harness.Peer, "answerer");
+			var root = PublicNote(poster, "<p>the root</p>");
+			// what a post carries is as old as the post: the collection is read again by its id
+			root["replies"] = new JsonObject
+			{
+				["id"] = IdOf(root) + "/replies", ["type"] = "Collection", ["first"] = new JsonObject { ["type"] = "CollectionPage", ["items"] = new JsonArray() }
+			};
+			Served(root);
+			var first = Reply(answerer, "first answer", root);
+			var second = Served(Reply(poster, "second answer", root));
+			var hidden = Reply(answerer, "for followers", root);
+			hidden["to"] = new JsonArray(answerer.Id + "/followers");
+			hidden["cc"] = new JsonArray();
+			Served(hidden);
+			var nested = Reply(poster, "nested", first);
+			var deeper = Served(Reply(answerer, "too deep", nested));
+			first["replies"] = IdOf(first) + "/replies";
+			Served(first);
+			nested["replies"] = IdOf(nested) + "/replies";
+			Served(nested);
+
+			Served(new JsonObject { ["id"] = IdOf(root) + "/replies", ["type"] = "Collection", ["first"] = IdOf(root) + "/replies/1" });
+			Served(new JsonObject
+			{
+				["id"] = IdOf(root) + "/replies/1", ["type"] = "CollectionPage", ["next"] = IdOf(root) + "/replies/2",
+				["items"] = new JsonArray(first.DeepClone(), IdOf(second))
+			});
+			Served(new JsonObject { ["id"] = IdOf(root) + "/replies/2", ["type"] = "CollectionPage", ["items"] = new JsonArray(IdOf(hidden)) });
+			Served(new JsonObject { ["id"] = IdOf(first) + "/replies", ["type"] = "OrderedCollection", ["orderedItems"] = new JsonArray(IdOf(nested)) });
+			Served(new JsonObject { ["id"] = IdOf(nested) + "/replies", ["type"] = "OrderedCollection", ["orderedItems"] = new JsonArray(IdOf(deeper)) });
+			var held = await Held(root);
+
+			Assert.Equal(3, await RunReplies(held));
+			var stored = await Stored(first, second, hidden, nested, deeper);
+			Assert.Equal(new[] { IdOf(first), IdOf(second), IdOf(nested) }.Order(), stored.Keys.Order());
+			Assert.Equal(held.ID, stored[IdOf(first)].AnsweringToPostId);
+			Assert.Equal(held.ID, stored[IdOf(second)].AnsweringToPostId);
+			Assert.Equal(stored[IdOf(first)].ID, stored[IdOf(nested)].AnsweringToPostId);
+			Assert.DoesNotContain(_harness.Peer.Requests, r => r.Path == new Uri(IdOf(nested) + "/replies").AbsolutePath);
+			Assert.All(_harness.Peer.Requests.Where(r => r.Path.EndsWith("/replies")), r => Assert.False(string.IsNullOrEmpty(r.Signature)));
+		}
+
+		[Fact]
+		public async Task A_conversation_container_is_read_before_the_context_and_only_its_added_posts_taken()
+		{
+			var owner = new RemoteActor(_harness.Peer, "owner");
+			var answerer = new RemoteActor(_harness.Peer, "answerer");
+			var root = PublicNote(owner, "<p>a conversation</p>");
+			var history = NewId(owner, "conversations");
+			root["contextHistory"] = history;
+			root["context"] = NewId(owner, "never");
+			Served(root);
+			var embedded = Served(Reply(answerer, "added whole", root));
+			var referenced = Served(Reply(owner, "added by reference", embedded));
+			var liked = Served(Reply(answerer, "only liked", root));
+			var target = new JsonObject { ["type"] = "OrderedCollection", ["id"] = history, ["attributedTo"] = owner.Id };
+			JsonObject Add(JsonNode activity) => new()
+			{
+				["id"] = NewId(owner, "activities"), ["type"] = "Add", ["actor"] = owner.Id, ["object"] = activity, ["target"] = target.DeepClone()
+			};
+			var create = Served(Create(owner, referenced));
+			create["object"] = IdOf(referenced);
+			Served(create);
+			var byReference = Served(Add(IdOf(create)));
+			Served(new JsonObject
+			{
+				["id"] = history, ["type"] = "OrderedCollection", ["attributedTo"] = owner.Id, ["collectionOf"] = "Activity",
+				["orderedItems"] = new JsonArray(Create(owner, root), Add(Create(answerer, embedded)), IdOf(byReference), Add(Activity(answerer, "Like", JsonValue.Create(IdOf(liked)))))
+			});
+			var held = await Held(root);
+
+			Assert.Equal(1, await RunReplies(held));
+			var stored = await Stored(embedded, referenced, liked);
+			Assert.Equal(new[] { IdOf(embedded), IdOf(referenced) }.Order(), stored.Keys.Order());
+			Assert.Equal(held.ID, stored[IdOf(embedded)].AnsweringToPostId);
+			Assert.Equal(stored[IdOf(embedded)].ID, stored[IdOf(referenced)].AnsweringToPostId);
+			Assert.DoesNotContain(_harness.Peer.Requests, r => r.Path == new Uri(root["context"]!.GetValue<string>()).AbsolutePath);
+		}
+
+		[Fact]
+		public async Task An_unchanged_context_is_not_read_again_while_it_counts_the_thread()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var answerer = new RemoteActor(_harness.Peer, "answerer");
+			var root = PublicNote(poster, "<p>a topic</p>");
+			var context = NewId(poster, "topics");
+			var path = new Uri(context).AbsolutePath;
+			root["context"] = context;
+			Served(root);
+			var first = Served(Reply(answerer, "first", root));
+			var later = Served(Reply(poster, "later", root));
+			// NodeBB's: every post inline, counted, and an ETag without quotes
+			JsonObject Thread(params JsonObject[] notes) => new()
+			{
+				["id"] = context, ["type"] = "OrderedCollection", ["totalItems"] = notes.Length,
+				["orderedItems"] = new JsonArray(notes.Select(n => (JsonNode)IdOf(n)).ToArray())
+			};
+			_harness.Peer.ServeTagged(path, Thread(root, first).ToJsonString(), "4f930186eb");
+			var held = await Held(root);
+			var handler = new RepliesJobHandler(_harness.Db, _harness.Remote, _harness.RemotePosts, _harness.Queue);
+
+			await handler.Handle(RepliesJobHandler.For(held, 1), token);
+			Assert.Equal("4f930186eb", (await DB.Default.Find<ThreadCollection>().Match(c => c.URI == context).ExecuteFirstAsync(token)).ETag);
+			// the same version: a 304, and nothing read
+			_harness.Peer.ServeTagged(path, Thread(root, first, later).ToJsonString(), "4f930186eb");
+			await handler.Handle(RepliesJobHandler.For(held, 1), token);
+			Assert.Equal("4f930186eb", _harness.Peer.Requests.Last(r => r.Path == path).Headers["If-None-Match"]);
+			Assert.Single(await Stored(first, later));
+			// a new one
+			_harness.Peer.ServeTagged(path, Thread(root, first, later).ToJsonString(), "5a0b");
+			await handler.Handle(RepliesJobHandler.For(held, 1), token);
+			Assert.Equal(2, (await Stored(first, later)).Count);
+			Assert.Equal("5a0b", (await DB.Default.Find<ThreadCollection>().Match(c => c.URI == context).ExecuteFirstAsync(token)).ETag);
+		}
+
+		[Fact]
+		public async Task A_paged_contexts_etag_is_not_kept_since_its_first_page_hides_what_is_added_later()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var root = PublicNote(poster, "<p>a long thread</p>");
+			var context = NewId(poster, "contexts");
+			root["context"] = context;
+			Served(root);
+			var answer = Served(Reply(poster, "on the second page", root));
+			_harness.Peer.ServeTagged(new Uri(context).AbsolutePath, new JsonObject
+			{
+				["id"] = context, ["type"] = "Collection",
+				["first"] = new JsonObject { ["type"] = "CollectionPage", ["items"] = new JsonArray(IdOf(root)), ["next"] = context + "/2" }
+			}.ToJsonString(), "W/\"first\"");
+			Served(new JsonObject { ["id"] = context + "/2", ["type"] = "CollectionPage", ["items"] = new JsonArray(IdOf(answer)) });
+			var held = await Held(root);
+
+			await new RepliesJobHandler(_harness.Db, _harness.Remote, _harness.RemotePosts, _harness.Queue).Handle(RepliesJobHandler.For(held, 1), token);
+			Assert.Single(await Stored(answer));
+			Assert.False(await DB.Default.Find<ThreadCollection>().Match(c => c.URI == context && c.ETag != null).ExecuteAnyAsync(token));
+		}
+
+		[Fact]
+		public async Task A_threads_context_collection_brings_every_reply_at_once()
+		{
+			var poster = new RemoteActor(_harness.Peer, "poster");
+			var answerer = new RemoteActor(_harness.Peer, "answerer");
+			var root = PublicNote(poster, "<p>a thread</p>");
+			var context = NewId(poster, "contexts");
+			root["context"] = context;
+			root["replies"] = NewId(poster, "never");
+			Served(root);
+			var answer = Served(Reply(answerer, "an answer", root));
+			var deep = Served(Reply(poster, "an answer to it", answer));
+			// FEP-f228 lets a context list the activities that made the thread
+			Served(new JsonObject
+			{
+				["id"] = context, ["type"] = "OrderedCollection",
+				["first"] = new JsonObject { ["type"] = "OrderedCollectionPage", ["orderedItems"] = new JsonArray(IdOf(root), Create(answerer, answer), IdOf(deep)) }
+			});
+			var held = await Held(root);
+
+			Assert.Equal(1, await RunReplies(held));
+			var stored = await Stored(answer, deep);
+			Assert.Equal(held.ID, stored[IdOf(answer)].AnsweringToPostId);
+			Assert.Equal(stored[IdOf(answer)].ID, stored[IdOf(deep)].AnsweringToPostId);
+			Assert.DoesNotContain(_harness.Peer.Requests, r => r.Path == new Uri(root["replies"]!.GetValue<string>()).AbsolutePath);
+		}
+
 		async Task<(LocalActor Alice, RemoteActor Mallory, Post Poll)> LocalPoll()
 		{
 			var token = TestContext.Current.CancellationToken;
@@ -357,9 +586,17 @@ namespace PrivaPub.Tests.Federation
 
 				await new MediaJanitor(media, options, NullLogger<MediaJanitor>.Instance).Sweep(token);
 
-				Assert.False(await DB.Default.Find<MediaAttachment>().Match(m => m.ID == stale.ID).ExecuteAnyAsync(token));
+				// never posted for a day: trashed, its files out of what /media/files serves at once
+				Assert.NotNull((await DB.Default.Find<MediaAttachment>().OneAsync(stale.ID, token)).TrashedAt);
 				Assert.False(File.Exists(Path.Combine(root, stale.FilePath)));
 				Assert.False(File.Exists(Path.Combine(root, stale.PreviewPath)));
+				Assert.True(File.Exists(Path.Combine(media.TrashRoot, stale.FilePath)));
+				// and once its grace has passed, deleted with its row
+				await DB.Default.Update<MediaAttachment>().MatchID(stale.ID).Modify(m => m.TrashedAt, DateTime.UtcNow - MediaJanitor.TrashGrace - TimeSpan.FromMinutes(1)).ExecuteAsync(token);
+				await new MediaJanitor(media, options, NullLogger<MediaJanitor>.Instance).Sweep(token);
+				Assert.False(await DB.Default.Find<MediaAttachment>().Match(m => m.ID == stale.ID).ExecuteAnyAsync(token));
+				Assert.False(File.Exists(Path.Combine(media.TrashRoot, stale.FilePath)));
+				Assert.False(File.Exists(Path.Combine(media.TrashRoot, stale.PreviewPath)));
 				Assert.True(await DB.Default.Find<MediaAttachment>().Match(m => m.ID == fresh.ID).ExecuteAnyAsync(token));
 				Assert.True(await DB.Default.Find<MediaAttachment>().Match(m => m.ID == attached.ID).ExecuteAnyAsync(token));
 				Assert.True(File.Exists(Path.Combine(root, fresh.FilePath)));
@@ -469,7 +706,7 @@ namespace PrivaPub.Tests.Federation
 			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
 		}
 
-		async Task<JobOutcome> Attempt(LocalActor signer, string inbox)
+		async Task<JobOutcome> Attempt(LocalActor signer, string inbox, int attempts = 1)
 		{
 			var token = TestContext.Current.CancellationToken;
 			var id = $"{Harness.Base}/a/{Guid.NewGuid():N}";
@@ -479,7 +716,7 @@ namespace PrivaPub.Tests.Federation
 				["object"] = new JsonObject { ["type"] = "Note", ["content"] = "hi" }
 			}, token);
 			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == $"{id}|{inbox}").ExecuteSingleAsync(token);
-			job.Attempts = 1;
+			job.Attempts = attempts;
 			var handler = new DeliveryJobHandler(_harness.Local, Peer.Http(), new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions())),
 				NullLogger<DeliveryJobHandler>.Instance);
 			return await handler.Handle(job, token);
@@ -533,5 +770,42 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal(JobResult.Retry, broken.Result);
 			Assert.StartsWith("500", broken.Error);
 		}
+
+		// a server that fails on one activity is up: its 500s are that delivery's to retry, and only a gateway's 502, 503 or
+		// 504 counts towards taking the host out (Smithereen's 500s on documents it could not read once held every delivery
+		// to it back for an hour)
+		[Fact]
+		public async Task Only_a_gateways_failures_take_the_host_out()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			_harness.Peer.Answer("/broken/inbox", 500);
+			_harness.Peer.Answer("/gateway/inbox", 502);
+
+			for (var i = 0; i < HostCircuitBreaker.Threshold; i++)
+				await Attempt(alice, _harness.Peer.A + "/broken/inbox");
+			var stillTried = await Attempt(alice, _harness.Peer.A + "/broken/inbox");
+			for (var i = 0; i < HostCircuitBreaker.Threshold; i++)
+				await Attempt(alice, _harness.Peer.A + "/gateway/inbox");
+			var heldBack = await Attempt(alice, _harness.Peer.A + "/broken/inbox");
+
+			Assert.Equal((JobResult.Retry, "500"), (stillTried.Result, stillTried.Error[..3]));
+			Assert.Equal((JobResult.Defer, "the host is unavailable"), (heldBack.Result, heldBack.Error));
+		}
+
+		// Mastodon's 422 for two first contacts racing to create one account, and its 409 for a held lock, are retried a
+		// few times; the third refusal is final like any other
+		[Fact]
+		public async Task Conflicts_and_unprocessable_answers_are_retried_twice_then_dead()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			_harness.Peer.Answer("/racing/inbox", 422);
+			_harness.Peer.Answer("/locked/inbox", 409);
+
+			Assert.Equal(JobResult.Retry, (await Attempt(alice, _harness.Peer.A + "/racing/inbox")).Result);
+			Assert.Equal(JobResult.Retry, (await Attempt(alice, _harness.Peer.A + "/locked/inbox", attempts: 2)).Result);
+			var final = await Attempt(alice, _harness.Peer.A + "/racing/inbox", attempts: 3);
+			Assert.Equal(JobResult.Dead, final.Result);
+			Assert.StartsWith("422", final.Error);
+		}
 	}
 }

PrivaPub.Tests/Federation/MoveTests.cs

@@ -0,0 +1,106 @@
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// An account moving to another (Mastodon's Move), believed as Mastodon believes it: sent by the moving account about
+	// itself, and the new account naming it among its alsoKnownAs
+	[Trait("Category", "Integration")]
+	public sealed class MoveTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		// the new account, serving a document that names the old one (or not)
+		RemoteActor Target(string name, RemoteActor aliasOf)
+		{
+			var target = new RemoteActor(_harness.Peer, name);
+			var document = target.Document();
+			if (aliasOf != default)
+				document["alsoKnownAs"] = new JsonArray(aliasOf.Id);
+			_harness.Peer.Serve(new Uri(target.Id).AbsolutePath, document.ToJsonString());
+			return target;
+		}
+
+		Task Move(RemoteActor sender, RemoteActor moved, RemoteActor target) =>
+			_harness.Deliver(sender, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(sender, "moves"), ["type"] = "Move", ["actor"] = sender.Id, ["object"] = moved.Id, ["target"] = target.Id
+			});
+
+		static Task<ForeignAvatar> Stored(RemoteActor actor) =>
+			DB.Default.Find<ForeignAvatar>().Match(a => a.ActorURI == actor.Id).ExecuteFirstAsync(TestContext.Current.CancellationToken);
+
+		// as Mastodon does it (owner decision 2026-10-05): the follow moves to the new account, in the same lists, and a mute
+		// or a block of the old account carries over
+		[Fact]
+		public async Task A_move_the_new_account_confirms_moves_the_personas_follows_lists_mutes_and_blocks()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var (_, bob) = await _harness.Persona("bob");
+			var old = new RemoteActor(_harness.Peer, "old");
+			await _harness.Remote.GetActor(old.Id, refresh: true, token);
+			await Follows(alice.Id, old);
+			var oldAccount = await Stored(old);
+			var list = new PersonaList { AvatarId = alice.Id, Title = "friends" };
+			await DB.Default.SaveAsync(list, token);
+			await DB.Default.SaveAsync(new PersonaListMember { ListId = list.ID, AvatarId = alice.Id, AccountId = oldAccount.ID }, token);
+			await _harness.Relationships.Mute(alice, old.Id, oldAccount.ID, hideNotifications: true, duration: default, token);
+			await _harness.Relationships.Block(bob, old.Id, oldAccount.ID, token);
+			var target = Target("new", aliasOf: old);
+
+			await Move(old, old, target);
+
+			var stored = await Stored(old);
+			Assert.Equal(target.Id, stored.MovedToURL);
+			var account = await new MastodonMapper(_harness.Db, _harness.Local).Account(stored.ID, token);
+			Assert.Equal(target.Name, account.Moved?.Username);
+			Assert.Contains(_harness.Ledger.Of("in"), e => e.Activity == "Move" && e.Reason == "moved");
+			var newAccount = await Stored(target);
+			Assert.True(await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == target.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == old.Id).ExecuteAnyAsync(token));
+			Assert.Contains(await _harness.Outgoing(target.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Follow");
+			Assert.Contains(await _harness.Outgoing(old.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Undo");
+			Assert.True(await DB.Default.Find<PersonaListMember>().Match(m => m.ListId == list.ID && m.AccountId == newAccount.ID).ExecuteAnyAsync(token));
+			Assert.True(await DB.Default.Find<Mute>().Match(m => m.AvatarId == alice.Id && m.TargetActorURI == target.Id).ExecuteAnyAsync(token));
+			Assert.True(await DB.Default.Find<Block>().Match(b => b.AvatarId == bob.Id && b.TargetActorURI == target.Id).ExecuteAnyAsync(token));
+		}
+
+		[Fact]
+		public async Task A_move_the_new_account_does_not_confirm_or_someone_else_sends_changes_nothing()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var old = new RemoteActor(_harness.Peer, "old");
+			var stranger = new RemoteActor(_harness.Peer, "stranger");
+			await Follows(alice.Id, old);
+			var unconfirmed = Target("new", aliasOf: default);
+			var hijack = Target("hijack", aliasOf: stranger);
+
+			await Move(old, old, unconfirmed);
+			await Move(stranger, old, hijack);
+
+			Assert.Null((await Stored(old)).MovedToURL);
+			Assert.Equal(new[] { "not-aliased", "not-self" }, _harness.Ledger.Of("in").Where(e => e.Activity == "Move").Select(e => e.Reason));
+		}
+	}
+}

PrivaPub.Tests/Federation/NoteParserTests.cs

@@ -35,6 +35,26 @@ namespace PrivaPub.Tests.Federation
 			}
 			""";
 
+		// Castopod's episode: its words in description, its sound in audio, the sound's name for a title
+		[Fact]
+		public void A_podcast_episode_is_read_with_its_words_sound_and_cover()
+		{
+			var episode = NoteParser.Parse(JsonNode.Parse("""
+				{"id":"https://castopod.test/@pod/episodes/one","type":"PodcastEpisode","published":"2026-10-06T09:08:17+00:00",
+				 "to":["https://www.w3.org/ns/activitystreams#Public"],"attributedTo":"https://castopod.test/@pod",
+				 "description":{"type":"Note","mediaType":"text/markdown","content":"Listen to the **meadow**","contentMap":{"en":"<p>Listen to the meadow</p>"}},
+				 "image":{"type":"Image","mediaType":"image/png","url":"https://castopod.test/media/cover.png"},
+				 "audio":{"id":"https://castopod.test/audio/one.mp3","type":"Audio","name":"Episode one","size":16791,"duration":4.02,
+				  "url":{"href":"https://castopod.test/audio/one.mp3","type":"Link","mediaType":"audio/mpeg"}}}
+				"""));
+
+			Assert.Equal(("PodcastEpisode", "Episode one", "https://castopod.test/media/cover.png"), (episode.Type, episode.Title, episode.CoverURL));
+			Assert.Contains("<strong>meadow</strong>", episode.ContentHtml);
+			var sound = Assert.Single(episode.Attachments);
+			Assert.Equal(("https://castopod.test/audio/one.mp3", "audio/mpeg"), (sound.RemoteURL, sound.ContentType));
+			Assert.Equal(4.02, episode.Audio.DurationSeconds);
+		}
+
 		[Fact]
 		public void Reads_a_mastodon_note()
 		{
@@ -57,6 +77,69 @@ namespace PrivaPub.Tests.Federation
 			Assert.Null(note.Updated);
 		}
 
+		// GoToSocial writes a lone tag, and lone to and cc, as plain values instead of arrays (captured by the town)
+		[Fact]
+		public void Reads_a_gotosocial_reply_whose_only_tag_and_audience_are_single_values()
+		{
+			var note = NoteParser.Parse(JsonNode.Parse(File.ReadAllText(Path.Combine(AppContext.BaseDirectory, "Fixtures", "gotosocial",
+				"followers-only-reply-one-tag.json"))));
+
+			var mention = Assert.Single(note.Mentions);
+			Assert.Equal("https://privapub.test/peasants/flor_pp98", mention.ActorURI);
+			Assert.Equal(["https://gts.test/users/ines_gt59/followers"], note.To);
+			Assert.Equal(["https://privapub.test/peasants/flor_pp98"], note.Cc);
+		}
+
+		// PeerTube's video whose comments wait for approval names who may comment (FEP-5624), apart from GoToSocial's policy
+		[Fact]
+		public void Reads_who_may_reply_pending_approval()
+		{
+			var video = NoteParser.Parse(JsonNode.Parse("""
+				{"id":"https://peertube.test/videos/watch/1","type":"Video","name":"a video","attributedTo":["https://peertube.test/accounts/pt"],
+				 "canReply":"https://www.w3.org/ns/activitystreams#Public","commentsEnabled":true}
+				"""));
+			var open = NoteParser.Parse(JsonNode.Parse("""
+				{"id":"https://peertube.test/videos/watch/2","type":"Video","name":"an open video","attributedTo":["https://peertube.test/accounts/pt"],
+				 "canReply":null,"commentsPolicy":1}
+				"""));
+			var note = NoteParser.Parse(JsonNode.Parse(MastodonNote));
+
+			Assert.Equal(["https://www.w3.org/ns/activitystreams#Public"], video.ReplyApprovals.Manual);
+			Assert.Null(video.ReplyPolicy);
+			Assert.Null(open.ReplyApprovals);
+			Assert.Null(note.ReplyApprovals);
+		}
+
+		// Pleroma's edited post carries its earlier versions (formerRepresentations, newest first)
+		[Fact]
+		public void Reads_the_earlier_versions_of_a_pleroma_edit()
+		{
+			var note = NoteParser.Parse(JsonNode.Parse(File.ReadAllText(Path.Combine(AppContext.BaseDirectory, "Fixtures", "pleroma", "edited.json"))));
+
+			var before = Assert.Single(note.FormerRepresentations);
+			Assert.StartsWith("tomorrow library garden bridge", before.ContentHtml);
+			Assert.Equal(new DateTime(2026, 10, 5, 0, 49, 58, DateTimeKind.Utc).AddTicks(8_600_710), before.EditedAt);
+			Assert.Null(before.SpoilerText);
+			Assert.EndsWith("(edited)", note.ContentHtml);
+		}
+
+		[Fact]
+		public void Earlier_versions_come_oldest_first_each_read_as_the_post_is()
+		{
+			var note = NoteParser.Parse(JsonNode.Parse("""
+				{"id":"https://pl.example/objects/1","type":"Note","attributedTo":"https://pl.example/users/carol","content":"<p>third</p>",
+				 "published":"2026-10-06T08:00:00Z","updated":"2026-10-06T09:00:00Z",
+				 "formerRepresentations":{"type":"OrderedCollection","totalItems":2,"orderedItems":[
+				  {"type":"Note","content":"<p>second</p>","summary":"careful","published":"2026-10-06T08:00:00Z","updated":"2026-10-06T08:30:00Z"},
+				  {"type":"Note","content":"<p>first<script>x</script></p>","summary":"","published":"2026-10-06T08:00:00Z"}]}}
+				"""));
+
+			Assert.Equal(["<p>first</p>", "<p>second</p>"], note.FormerRepresentations.Select(r => r.ContentHtml));
+			Assert.Equal([new DateTime(2026, 10, 6, 8, 0, 0, DateTimeKind.Utc), new DateTime(2026, 10, 6, 8, 30, 0, DateTimeKind.Utc)],
+				note.FormerRepresentations.Select(r => r.EditedAt));
+			Assert.Equal([(default(string), false), ("careful", true)], note.FormerRepresentations.Select(r => (r.SpoilerText, r.HasContentWarning)));
+		}
+
 		[Fact]
 		public void Reads_a_lemmy_page_with_a_title()
 		{

PrivaPub.Tests/Federation/ObjectShapesTests.cs

@@ -1,4 +1,4 @@
-using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Api.Mastodon.Mappers;
 using PrivaPub.Federation.Objects;
 using PrivaPub.Models.Post;
 
@@ -79,6 +79,51 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal("2026-10-03 10:00 – 13:00 (Europe/Rome) · Biblioteca", MastodonMapper.EventLine(note.Event));
 		}
 
+		[Fact]
+		public void Keeps_a_pixelfed_place_whose_coordinates_are_strings()
+		{
+			var note = Parse("""
+				{
+					"id": "https://pixel.example/p/ann/1", "type": "Note", "attributedTo": "https://pixel.example/users/ann", "content": "<p>view</p>",
+					"location": { "type": "Place", "name": "Tokyo", "longitude": "139.6917", "latitude": "35.6895", "country": "Japan" },
+					"commentsEnabled": true
+				}
+				""");
+
+			Assert.Equal(("Tokyo", 35.6895, 139.6917, "Japan"), (note.Place.Name, note.Place.Latitude, note.Place.Longitude, note.Place.Country));
+			Assert.Null(note.Event);
+		}
+
+		[Theory]
+		[InlineData("null")]
+		[InlineData("""{ "type": "Place", "name": "Nowhere" }""")]
+		[InlineData("""{ "type": "Place", "name": "Off the map", "latitude": 123, "longitude": 9 }""")]
+		[InlineData("""{ "type": "Place", "latitude": "north", "longitude": "9.19" }""")]
+		[InlineData("""{ "type": "VirtualLocation", "url": "https://meet.example/a", "latitude": 45, "longitude": 9 }""")]
+		public void Has_no_place_without_a_place_with_coordinates(string location)
+		{
+			var note = Parse($$"""
+				{ "id": "https://pixel.example/p/ann/2", "type": "Note", "attributedTo": "https://pixel.example/users/ann", "content": "<p>x</p>", "location": {{location}} }
+				""");
+
+			Assert.Null(note.Place);
+		}
+
+		[Fact]
+		public void An_events_location_stays_the_events_own()
+		{
+			var note = Parse("""
+				{
+					"id": "https://events.example/events/10", "type": "Event", "name": "Picnic", "startTime": "2026-10-03T10:00:00+02:00",
+					"location": { "type": "Place", "name": "Park", "latitude": 45.07, "longitude": 7.68 },
+					"attributedTo": "https://events.example/@club"
+				}
+				""");
+
+			Assert.Null(note.Place);
+			Assert.Equal("Park", Assert.Single(note.Event.Places).Name);
+		}
+
 		[Fact]
 		public void Keeps_a_lemmy_link_post_as_a_link_with_its_thumbnail()
 		{

PrivaPub.Tests/Federation/ParticipationTests.cs

@@ -0,0 +1,100 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// a persona joins a remote event (owner decision 2026-10-05): Join, answered Accept or Reject; Leave
+	[Trait("Category", "Integration")]
+	public sealed class ParticipationTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		async Task<(PrivaPub.Federation.Actors.LocalActor Alice, RemoteActor Group, Post Event)> Announced(string joinMode = "free")
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var group = new RemoteActor(_harness.Peer, "group", type: "Group");
+			await Follows(alice.Id, group);
+			var happening = new JsonObject
+			{
+				["id"] = NewId(group, "events"), ["type"] = "Event", ["name"] = "A picnic", ["content"] = "<p>bring bread</p>",
+				["attributedTo"] = group.Id, ["startTime"] = DateTime.UtcNow.AddDays(3).ToString("O"), ["joinMode"] = joinMode,
+				["to"] = new JsonArray(PrivaPub.Federation.Objects.Addressing.Public), ["cc"] = new JsonArray(group.Id + "/followers")
+			};
+			await _harness.Deliver(group, "/human-centipede", Create(group, happening));
+			return (alice, group, await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(happening)).ExecuteSingleAsync(token));
+		}
+
+		Task<Participation> Of(PrivaPub.Federation.Actors.LocalActor alice, Post happening) =>
+			DB.Default.Find<Participation>().Match(p => p.AvatarId == alice.Id && p.PostId == happening.ID).ExecuteFirstAsync(TestContext.Current.CancellationToken);
+
+		[Fact]
+		public async Task A_persona_joins_an_event_its_server_accepts_and_leaves_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, group, happening) = await Announced();
+
+			Assert.True((await _harness.Participations.Join(alice, happening.ID, token)).Ok);
+
+			var join = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Join");
+			Assert.Equal((alice.Uri, happening.ObjectURI), (join["actor"]!.GetValue<string>(), join["object"]!.GetValue<string>()));
+			Assert.Equal(ParticipationState.Pending, (await Of(alice, happening)).State);
+
+			await _harness.Deliver(group, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(group, "accepts"), ["type"] = "Accept", ["actor"] = group.Id, ["object"] = join["id"]!.GetValue<string>()
+			});
+			Assert.Equal(ParticipationState.Accepted, (await Of(alice, happening)).State);
+
+			Assert.True((await _harness.Participations.Leave(alice, happening.ID, token)).Ok);
+			Assert.Null(await Of(alice, happening));
+			var leave = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Leave");
+			Assert.Equal(happening.ObjectURI, leave["object"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task A_refusal_counts_an_answer_from_another_server_does_not_and_an_invitation_only_event_is_not_joined()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (alice, group, happening) = await Announced();
+			await _harness.Participations.Join(alice, happening.ID, token);
+			var join = Assert.Single(await _harness.Outgoing(group.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Join");
+
+			var stranger = new RemoteActor(_harness.Peer, "stranger", _harness.Peer.B);
+			await _harness.Deliver(stranger, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(stranger, "accepts"), ["type"] = "Accept", ["actor"] = stranger.Id, ["object"] = join["id"]!.GetValue<string>()
+			});
+			Assert.Equal(ParticipationState.Pending, (await Of(alice, happening)).State);
+
+			await _harness.Deliver(group, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(group, "rejects"), ["type"] = "Reject", ["actor"] = group.Id,
+				["object"] = new JsonObject { ["id"] = join["id"]!.GetValue<string>(), ["type"] = "Join", ["actor"] = alice.Uri, ["object"] = happening.ObjectURI }
+			});
+			Assert.Equal(ParticipationState.Rejected, (await Of(alice, happening)).State);
+
+			var (carol, _, invitationOnly) = await Announced("invite");
+			Assert.Equal(422, (await _harness.Participations.Join(carol, invitationOnly.ID, token)).Status);
+		}
+	}
+}

PrivaPub.Tests/Federation/ReactionTests.cs

@@ -17,6 +17,9 @@ namespace PrivaPub.Tests.Federation
 		[InlineData(":blobcat@k.example:", "blobcat")]
 		[InlineData("👍🏽", "👍🏽")]
 		[InlineData("❤️", "❤️")]
+		[InlineData("❤", "❤️")]
+		[InlineData("✌", "✌️")]
+		[InlineData("🔥\uFE0F", "🔥")]
 		[InlineData("nope", null)]
 		[InlineData("👍👍", null)]
 		[InlineData(":unknown:", null)]

PrivaPub.Tests/Federation/RelayTests.cs

@@ -0,0 +1,143 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// relays the configuration names: the instance actor follows Public there, and the public posts the relay passes on,
+	// forwarded or announced, come to the federated timeline as their authors' posts; nothing else is taken from it
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class RelayTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+			{
+				_harness.RelayOptions.Relays.Clear();
+				await _harness.Relays.Reconcile(TestContext.Current.CancellationToken);
+				await _harness.DisposeAsync();
+			}
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+
+		string Note(RemoteActor author, string text, string to = "https://www.w3.org/ns/activitystreams#Public")
+		{
+			var path = $"/notes/{Guid.NewGuid():N}";
+			_harness.Peer.Serve(path, new JsonObject
+			{
+				["id"] = Origin(author) + path, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+				["to"] = new JsonArray(to), ["published"] = DateTime.UtcNow.ToString("O")
+			}.ToJsonString());
+			return Origin(author) + path;
+		}
+
+		JsonObject Create(RemoteActor author, string noteId) => new()
+		{
+			["id"] = noteId + "/activity", ["type"] = "Create", ["actor"] = author.Id,
+			["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"),
+			["object"] = new JsonObject { ["id"] = noteId, ["type"] = "Note", ["attributedTo"] = author.Id }
+		};
+
+		// a relay the instance actor subscribes to, which accepts
+		async Task<RemoteActor> Subscribed()
+		{
+			var relay = new RemoteActor(_harness.Peer, "relay", type: "Service");
+			_harness.RelayOptions.Relays.Add(relay.Id);
+			await _harness.Relays.Reconcile(Token);
+			var follow = Assert.Single(await _harness.Outgoing(relay.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Follow");
+			await _harness.Deliver(relay, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{relay.Id}#accept-{Guid.NewGuid():N}", ["type"] = "Accept", ["actor"] = relay.Id, ["object"] = follow.DeepClone()
+			});
+			return relay;
+		}
+
+		[Fact]
+		public async Task The_instance_actor_follows_public_at_a_configured_relay_and_takes_its_answer()
+		{
+			var relay = await Subscribed();
+
+			var follow = Assert.Single(await _harness.Outgoing(relay.Id + "/inbox"));
+			Assert.Equal(("Follow", "https://www.w3.org/ns/activitystreams#Public"), (follow["type"]!.GetValue<string>(), follow["object"]!.GetValue<string>()));
+			Assert.Equal((await _harness.Local.GetInstanceActor(Token)).Uri, follow["actor"]!.GetValue<string>());
+			Assert.Equal(RelayState.Accepted, (await DB.Default.Find<RelaySubscription>().Match(s => s.ActorURI == relay.Id).ExecuteSingleAsync(Token)).State);
+			Assert.True(await _harness.Relays.Passes(relay.Id, Token));
+
+			_harness.RelayOptions.Relays.Clear();
+			await _harness.Relays.Reconcile(Token);
+
+			Assert.Contains(await _harness.Outgoing(relay.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Undo");
+			Assert.False(await DB.Default.Find<RelaySubscription>().Match(s => s.ActorURI == relay.Id).ExecuteAnyAsync(Token));
+		}
+
+		[Fact]
+		public async Task A_public_post_a_subscribed_relay_forwards_is_kept_and_one_from_anyone_else_is_not()
+		{
+			var relay = await Subscribed();
+			var stranger = new RemoteActor(_harness.Peer, "stranger", type: "Service");
+			var author = new RemoteActor(_harness.Peer, "author", _harness.Peer.B);
+			var relayed = Note(author, "through the relay");
+			var forwarded = Note(author, "through a stranger");
+			var followersOnly = Note(author, "for followers", author.Id + "/followers");
+
+			await _harness.Deliver(relay, "/human-centipede", Create(author, relayed));
+			await _harness.Deliver(stranger, "/human-centipede", Create(author, forwarded));
+			await _harness.Deliver(relay, "/human-centipede", Create(author, followersOnly));
+
+			var kept = await DB.Default.Find<Post>().Match(p => p.ActorURI == author.Id).ExecuteAsync(Token);
+			Assert.Equal(new[] { relayed }, kept.Select(p => p.ObjectURI));
+			Assert.Equal(PostVisibility.Public, kept[0].Visibility);
+		}
+
+		// owner decision 2026-10-06: a persona's public post, its edit and its deletion go to the relays too; nothing less
+		// public does, nor a boost
+		[Fact]
+		public async Task A_personas_public_post_goes_to_the_relays_and_nothing_less_public()
+		{
+			var relay = await Subscribed();
+			var (_, alice) = await _harness.Persona("alice");
+			var token = Token;
+
+			var open = await _harness.Statuses.Publish(alice, new PrivaPub.Domain.Statuses.StatusDraft { Text = "for everyone", Visibility = PostVisibility.Public }, token);
+			await _harness.Statuses.Publish(alice, new PrivaPub.Domain.Statuses.StatusDraft { Text = "quietly", Visibility = PostVisibility.Unlisted }, token);
+			await _harness.Statuses.Publish(alice, new PrivaPub.Domain.Statuses.StatusDraft { Text = "for followers", Visibility = PostVisibility.FollowersOnly }, token);
+
+			var sent = (await _harness.Outgoing(relay.Id + "/inbox")).Where(a => a["type"]!.GetValue<string>() == "Create").ToList();
+			var create = Assert.Single(sent);
+			Assert.Equal(alice.PostUri(open.Post.ID), create["object"]!["id"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task A_post_a_relay_announces_is_its_authors_never_the_relays_boost()
+		{
+			var relay = await Subscribed();
+			var author = new RemoteActor(_harness.Peer, "author", _harness.Peer.B);
+			var noteId = Note(author, "announced by the relay");
+
+			await _harness.Deliver(relay, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{relay.Id}/activities/{Guid.NewGuid():N}", ["type"] = "Announce", ["actor"] = relay.Id,
+				["to"] = new JsonArray(relay.Id + "/followers"), ["object"] = noteId
+			});
+
+			var post = await DB.Default.Find<Post>().Match(p => p.ObjectURI == noteId).ExecuteSingleAsync(Token);
+			Assert.Equal(author.Id, post.ActorURI);
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ReblogOfPostId == post.ID).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Federation/RemoteHandleTests.cs

@@ -0,0 +1,117 @@
+using Microsoft.Extensions.Caching.Memory;
+
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Relationships;
+using PrivaPub.Federation.Actors;
+using PrivaPub.Infrastructure.Http;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// an account's handle: user@host, or the domain its `webfinger` names (FEP-2c59; Mastodon's LOCAL_DOMAIN apart from
+	// its WEB_DOMAIN) once that domain's WebFinger says the handle is this account
+	[Trait("Category", "Integration")]
+	public sealed class RemoteHandleTests : IAsyncLifetime
+	{
+		Harness _harness;
+		RemoteActorService _remote;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+			_remote = new RemoteActorService(Peer.Http(), _harness.Local, new MemoryCache(new MemoryCacheOptions()), _harness.Db,
+				new StaticOptions<FederationOptions>(new FederationOptions { AllowPrivateNetworks = true, AllowPlainHttp = true }));
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		// the actor at the peer's first address, its handle at the second
+		RemoteActor Actor(string name) => Serve(new RemoteActor(_harness.Peer, name));
+
+		RemoteActor Serve(RemoteActor actor, string preferredUsername = default)
+		{
+			var document = actor.Document();
+			if (preferredUsername != default)
+				document["preferredUsername"] = preferredUsername;
+			document["webfinger"] = $"acct:{preferredUsername ?? actor.Name}@{new Uri(_harness.Peer.B).Authority}";
+			_harness.Peer.Serve(new Uri(actor.Id).AbsolutePath, document.ToJsonString());
+			return actor;
+		}
+
+		void WebFinger(string self) => _harness.Peer.ServeText("/.well-known/webfinger", new JsonObject
+		{
+			["links"] = new JsonArray(new JsonObject { ["rel"] = "self", ["type"] = "application/activity+json", ["href"] = self })
+		}.ToJsonString(), "application/jrd+json");
+
+		[Fact]
+		public async Task A_handle_on_another_domain_is_kept_once_its_webfinger_agrees()
+		{
+			var actor = Actor("split");
+			WebFinger(actor.Id);
+
+			var stored = await _remote.GetActor(actor.Id, refresh: true, TestContext.Current.CancellationToken);
+
+			Assert.Equal(new Uri(_harness.Peer.B).Authority, stored.Domain);
+		}
+
+		[Fact]
+		public async Task A_handle_its_webfinger_does_not_confirm_stays_on_the_actors_host()
+		{
+			var actor = Actor("claims");
+			WebFinger("http://localhost/users/someone-else");
+
+			var stored = await _remote.GetActor(actor.Id, refresh: true, TestContext.Current.CancellationToken);
+
+			Assert.Equal(new Uri(actor.Id).Authority, stored.Domain);
+		}
+
+		[Fact]
+		public async Task A_renamed_account_is_asked_again()
+		{
+			var actor = Actor("renames");
+			WebFinger(actor.Id);
+			await _remote.GetActor(actor.Id, refresh: true, TestContext.Current.CancellationToken);
+
+			Serve(actor, "renamed");
+			WebFinger("http://localhost/users/someone-else");
+			// (another cache: the first fetch holds the actor back for a while)
+			var later = new RemoteActorService(Peer.Http(), _harness.Local, new MemoryCache(new MemoryCacheOptions()), _harness.Db,
+				new StaticOptions<FederationOptions>(new FederationOptions { AllowPrivateNetworks = true, AllowPlainHttp = true }));
+			var stored = await later.GetActor(actor.Id, refresh: true, TestContext.Current.CancellationToken);
+
+			Assert.Equal("renamed", stored.UserName);
+			Assert.Equal(new Uri(actor.Id).Authority, stored.Domain);
+		}
+
+		[Fact]
+		public async Task A_persona_blocking_the_handles_server_hides_the_account()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var split = Actor("split");
+			WebFinger(split.Id);
+			await _remote.GetActor(split.Id, refresh: true, token);
+			var claims = Actor("claims");
+			WebFinger("http://localhost/users/someone-else");
+			await new RemoteActorService(Peer.Http(), _harness.Local, new MemoryCache(new MemoryCacheOptions()), _harness.Db,
+				new StaticOptions<FederationOptions>(new FederationOptions { AllowPrivateNetworks = true, AllowPlainHttp = true }))
+				.GetActor(claims.Id, refresh: true, token);
+
+			await DB.Default.SaveAsync(new AccountDomainBlock { AvatarId = alice.Id, Domain = new Uri(_harness.Peer.B).Host }, token);
+
+			Assert.Equal([split.Id], await Hidden.AuthorsHiddenFrom(alice.Id, new[] { split.Id, claims.Id }, forNotifications: false, token));
+			Assert.Contains(alice.Id, await Hidden.RecipientsHiding(new[] { alice.Id }, split.Id, token));
+			Assert.Empty(await Hidden.RecipientsHiding(new[] { alice.Id }, claims.Id, token));
+		}
+	}
+}

PrivaPub.Tests/Federation/ReplyRelayTests.cs

@@ -0,0 +1,114 @@
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// Inbox forwarding of replies (owner decision 2026-10-05): a reply to a persona's post reaches the persona's followers,
+	// who are not among those its author's server sends it to
+	[Trait("Category", "Integration")]
+	public sealed class ReplyRelayTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		// alice's post; bob replies from his server, fan follows alice from another, pal from bob's
+		async Task<(PrivaPub.Federation.Actors.LocalActor Alice, Post Post, RemoteActor Bob, RemoteActor Fan, RemoteActor Pal)> Thread()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob");
+			var fan = new RemoteActor(_harness.Peer, "fan", _harness.Peer.B);
+			var pal = new RemoteActor(_harness.Peer, "pal");
+			await _harness.FollowedBy(alice, fan);
+			await _harness.FollowedBy(alice, pal);
+			var post = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "what do you think?" }, token)).Post;
+			return (alice, post, bob, fan, pal);
+		}
+
+		JsonObject Reply(RemoteActor bob, Post post, string visibility = "public")
+		{
+			var reply = PublicNote(bob, "<p>I think so</p>", post.ActorURI);
+			reply["inReplyTo"] = post.ObjectURI;
+			if (visibility == "followers")
+			{
+				reply["to"] = new JsonArray(bob.Id + "/followers");
+				reply["cc"] = new JsonArray(post.ActorURI);
+			}
+			return reply;
+		}
+
+		Task<List<JsonObject>> At(RemoteActor follower) => _harness.Outgoing(follower.SharedInbox);
+
+		[Fact]
+		public async Task A_public_reply_to_a_personas_post_reaches_its_followers_as_it_came_and_not_its_authors_server()
+		{
+			var (_, post, bob, fan, pal) = await Thread();
+			var create = Create(bob, Reply(bob, post));
+			create["signature"] = new JsonObject { ["type"] = "RsaSignature2017", ["signatureValue"] = "kept as it came" };
+
+			await _harness.Deliver(bob, "/human-centipede", create);
+
+			var relayed = Assert.Single(await At(fan), a => a["id"]!.GetValue<string>() == IdOf(create));
+			Assert.Equal(bob.Id, relayed["actor"]!.GetValue<string>());
+			Assert.Equal("kept as it came", relayed["signature"]!["signatureValue"]!.GetValue<string>());
+			Assert.DoesNotContain(await At(pal), a => a["id"]!.GetValue<string>() == IdOf(create));
+		}
+
+		[Fact]
+		public async Task Its_edit_and_deletion_follow_it_and_a_followers_only_reply_stays_where_it_was_sent()
+		{
+			var (_, post, bob, fan, _) = await Thread();
+			var reply = Reply(bob, post);
+			await _harness.Deliver(bob, "/human-centipede", Create(bob, reply));
+			var edited = (JsonObject)reply.DeepClone();
+			edited["content"] = "<p>I think so, on second thought</p>";
+			edited["updated"] = DateTime.UtcNow.AddMinutes(1).ToString("O");
+			var update = Activity(bob, "Update", edited);
+			await _harness.Deliver(bob, "/human-centipede", update);
+			var delete = Activity(bob, "Delete", JsonValue.Create(IdOf(reply))!);
+			await _harness.Deliver(bob, "/human-centipede", delete);
+
+			var relayed = (await At(fan)).Select(a => a["id"]!.GetValue<string>()).ToList();
+			Assert.Contains(IdOf(update), relayed);
+			Assert.Contains(IdOf(delete), relayed);
+
+			var quiet = Create(bob, Reply(bob, post, "followers"));
+			await _harness.Deliver(bob, "/human-centipede", quiet);
+			Assert.DoesNotContain(await At(fan), a => a["id"]!.GetValue<string>() == IdOf(quiet));
+		}
+
+		[Fact]
+		public async Task A_reply_that_reached_us_forwarded_is_not_passed_on_again()
+		{
+			var (_, post, bob, fan, _) = await Thread();
+			var other = new RemoteActor(_harness.Peer, "other", _harness.Peer.B);
+			var reply = Reply(bob, post);
+			_harness.Peer.Serve(new Uri(IdOf(reply)).AbsolutePath, reply.ToJsonString());
+			var create = Create(bob, reply);
+
+			var result = await _harness.Deliver(other, "/human-centipede", create);
+
+			Assert.Equal("forwarded", result.Reason);
+			Assert.True(await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(reply)).ExecuteAnyAsync(TestContext.Current.CancellationToken));
+			Assert.DoesNotContain(await At(fan), a => a["id"]!.GetValue<string>() == IdOf(create));
+		}
+	}
+}

PrivaPub.Tests/Federation/ReusedIdTests.cs

@@ -0,0 +1,64 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.FederatedSeeds;
+
+namespace PrivaPub.Tests.Federation
+{
+	// A deleted remote post is never brought back by its own Create, however late it comes; an id its server gives a new
+	// post afterwards (Gancio numbers an event after the last one it keeps) is that new post
+	[Trait("Category", "Integration")]
+	public sealed class ReusedIdTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task A_deleted_posts_create_stays_dropped_and_a_new_post_under_its_id_is_kept()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await Follows(alice.Id, carol);
+			var first = PublicNote(carol, "<p>the first event</p>");
+			first["published"] = DateTime.UtcNow.AddMinutes(-10).ToString("O");
+			await _harness.Deliver(carol, "/human-centipede", Create(carol, first));
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = NewId(carol, "deletes"), ["type"] = "Delete", ["actor"] = carol.Id,
+				["object"] = new JsonObject { ["id"] = IdOf(first), ["type"] = "Tombstone" }
+			});
+			Assert.True(await DB.Default.Find<DeletedObject>().Match(d => d.ObjectURI == IdOf(first)).ExecuteAnyAsync(token));
+
+			// the first Create again, late
+			await _harness.Deliver(carol, "/human-centipede", Create(carol, (JsonObject)first.DeepClone()));
+			Assert.False(await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(first) && !p.DeletedAt.HasValue).ExecuteAnyAsync(token));
+
+			var second = PublicNote(carol, "<p>a new event, numbered as the first</p>");
+			second["id"] = IdOf(first);
+			second["published"] = DateTime.UtcNow.ToString("O");
+			await _harness.Deliver(carol, "/human-centipede", Create(carol, second));
+
+			var kept = await DB.Default.Find<Post>().Match(p => p.ObjectURI == IdOf(first) && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			Assert.Contains("a new event", kept?.ContentHtml);
+			Assert.False(await DB.Default.Find<DeletedObject>().Match(d => d.ObjectURI == IdOf(first)).ExecuteAnyAsync(token));
+		}
+	}
+}

PrivaPub.Tests/Federation/ServiceReportTests.cs

@@ -0,0 +1,252 @@
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging.Abstractions;
+
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Outbox;
+using PrivaPub.Federation.Signing;
+using PrivaPub.Infrastructure.Http;
+using PrivaPub.Infrastructure.Jobs;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
+using PrivaPub.Tests.Support;
+
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// Lemmy takes a report only from a person or a service, about one post or comment, addressed to its community (owner
+	// decision 2026-10-06): a report about a post in a community on a Lemmy leaves from the server's reporter, one per post.
+	// Alone in its collection: the server rows it writes for the peer's hosts decide for whoever reports there.
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class ServiceReportTests : IAsyncLifetime
+	{
+		static readonly string[] PeerHosts = { "localhost", "127.0.0.1" };
+
+		// (a test sees only the deliveries queued since it began: the others' share the database)
+		readonly DateTime _started = DateTime.UtcNow;
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness == default)
+				return;
+			await DB.Default.DeleteAsync<RemoteInstance>(i => PeerHosts.Contains(i.Host));
+			await _harness.DisposeAsync();
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		static string Origin(RemoteActor actor) => new Uri(actor.Id).GetLeftPart(UriPartial.Authority);
+
+		// what NodeInfo said the server at that host runs
+		static async Task Runs(string host, string software)
+		{
+			await DB.Default.DeleteAsync<RemoteInstance>(i => i.Host == host);
+			await DB.Default.SaveAsync(new RemoteInstance { Host = host, Software = software, SoftwareVersion = "1.0.0" }, Token);
+		}
+
+		async Task<ForeignAvatar> Known(RemoteActor actor) => await _harness.Remote.GetActor(actor.Id, refresh: false, Token);
+
+		static async Task<Post> Held(RemoteActor author, string community = default, Post parent = default)
+		{
+			var post = new Post
+			{
+				ObjectURI = $"{Origin(author)}/post/{Guid.NewGuid():N}",
+				ActorURI = author.Id,
+				AudienceURI = community,
+				AnsweringToPostId = parent?.ID,
+				ContentHtml = "<p>reported</p>"
+			};
+			await DB.Default.SaveAsync(post, Token);
+			return post;
+		}
+
+		async Task<List<DeliveryPayload>> Queued() =>
+			(await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.Deliver && j.CreatedAt >= _started).ExecuteAsync(Token))
+				.Select(j => JsonSerializer.Deserialize<DeliveryPayload>(j.Payload))
+				.ToList();
+
+		// a community on a Lemmy, or on a server that takes reports as Lemmy does (the peer as localhost), and one of its posters there
+		async Task<(RemoteActor Community, RemoteActor Poster)> OnLemmy(string software = "lemmy")
+		{
+			var community = new RemoteActor(_harness.Peer, "cats", _harness.Peer.B, type: "Group", sharedInbox: true);
+			var poster = new RemoteActor(_harness.Peer, "poster", _harness.Peer.B);
+			await Known(community);
+			await Known(poster);
+			await Runs("localhost", software);
+			return (community, poster);
+		}
+
+		// PieFed and Mbin take it too, proven live (2026-10-06); NodeInfo names Lemmy as "lemmy" and kbin's heir as "mbin"
+		[Theory]
+		[InlineData("lemmy")]
+		[InlineData("Lemmy")]
+		[InlineData("piefed")]
+		[InlineData("mbin")]
+		public async Task A_post_in_a_lemmy_community_is_reported_to_its_community_by_the_reporter_and_nowhere_else(string software)
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (community, poster) = await OnLemmy(software);
+			var post = await Held(poster, community.Id);
+			var reporter = await _harness.Local.GetReporterActor(Token);
+
+			var report = await _harness.Reports.File(alice, (await Known(poster)).ID, new[] { post.ID }, "  a slur in the title ", "violation", forward: true, Token);
+
+			Assert.True(report.Forwarded);
+			var flag = Assert.Single(await _harness.Outgoing(community.SharedInbox));
+			Assert.Equal("Flag", flag["type"]!.GetValue<string>());
+			Assert.Equal(reporter.Uri, flag["actor"]!.GetValue<string>());
+			Assert.EndsWith("/peasants/privapub_reports", reporter.Uri);
+			Assert.StartsWith(reporter.Uri + "/", flag["id"]!.GetValue<string>());
+			Assert.Equal(new[] { community.Id }, flag["to"]!.AsArray().Select(t => t!.GetValue<string>()));
+			Assert.Equal(community.Id, flag["audience"]!.GetValue<string>());
+			Assert.Equal(post.ObjectURI, flag["object"]!.GetValue<string>());
+			Assert.Equal("a slur in the title", flag["summary"]!.GetValue<string>());
+			Assert.Equal("a slur in the title", flag["content"]!.GetValue<string>());
+			Assert.Empty(await _harness.Outgoing(poster.Id + "/inbox"));
+			Assert.DoesNotContain(await Queued(), q => q.Inbox != community.SharedInbox && q.Body.Contains(post.ObjectURI));
+			Assert.DoesNotContain(alice.UserName, flag.ToJsonString());
+			Assert.DoesNotContain(alice.Id, flag.ToJsonString());
+			var queued = Assert.Single(await Queued(), q => q.Inbox == community.SharedInbox);
+			Assert.Equal(LocalActorKind.Reporter, queued.SignerKind);
+			Assert.Equal(reporter.Id, queued.SignerId);
+		}
+
+		[Fact]
+		public async Task The_reporter_signs_its_flag_with_its_own_key()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (community, poster) = await OnLemmy();
+			var post = await Held(poster, community.Id);
+			var reporter = await _harness.Local.GetReporterActor(Token);
+			var instance = await _harness.Local.GetInstanceActor(Token);
+			_harness.Peer.Answer("/inbox", 202);
+			await _harness.Reports.File(alice, (await Known(poster)).ID, new[] { post.ID }, default, "spam", forward: true, Token);
+			var job = await DB.Default.Find<Job>()
+				.Match(j => j.Kind == JobKind.Deliver && j.DedupeKey.StartsWith(reporter.ActivityUri($"flag-")))
+				.Sort(j => j.CreatedAt, Order.Descending).ExecuteFirstAsync(Token);
+
+			var handler = new DeliveryJobHandler(_harness.Local, Peer.Http(), new HostCircuitBreaker(new MemoryCache(new MemoryCacheOptions())),
+				NullLogger<DeliveryJobHandler>.Instance);
+			var outcome = await handler.Handle(job, Token);
+
+			Assert.Equal(JobResult.Done, outcome.Result);
+			var received = Assert.Single(_harness.Peer.Requests, r => r.Path == "/inbox" && r.Method == "POST");
+			// no words: Lemmy takes no report without a reason, so the category is it
+			Assert.Equal("spam", JsonNode.Parse(received.Body)!["summary"]!.GetValue<string>());
+			var signature = HttpSignatures.Parse(received.Signature);
+			Assert.Equal(reporter.KeyId, signature.KeyId);
+			Assert.NotEqual(instance.PublicKeyPem, reporter.PublicKeyPem);
+			var signingString = $"(request-target): post /inbox\nhost: {received.Headers["Host"]}\ndate: {received.Headers["Date"]}\ndigest: {received.Headers["Digest"]}";
+			using var key = RSA.Create();
+			key.ImportFromPem(reporter.PublicKeyPem);
+			Assert.True(key.VerifyData(Encoding.UTF8.GetBytes(signingString), signature.Signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1));
+		}
+
+		[Fact]
+		public async Task A_comment_finds_its_community_through_its_thread_and_two_posts_are_two_flags()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (community, poster) = await OnLemmy();
+			var thread = await Held(poster, community.Id);
+			var comment = await Held(poster, parent: thread);
+			var answer = await Held(poster, parent: comment);
+
+			var report = await _harness.Reports.File(alice, (await Known(poster)).ID, new[] { comment.ID, answer.ID }, "harassment", "other", forward: true, Token);
+
+			Assert.True(report.Forwarded);
+			var flags = await _harness.Outgoing(community.SharedInbox);
+			Assert.Equal(2, flags.Count);
+			Assert.Equal(new[] { comment.ObjectURI, answer.ObjectURI }.Order(), flags.Select(f => f["object"]!.GetValue<string>()).Order());
+			Assert.All(flags, f => Assert.Equal(community.Id, f["to"]![0]!.GetValue<string>()));
+			Assert.Equal(2, flags.Select(f => f["id"]!.GetValue<string>()).Distinct().Count());
+		}
+
+		[Fact]
+		public async Task An_account_alone_on_a_lemmy_is_reported_to_nobody()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (community, poster) = await OnLemmy();
+
+			var report = await _harness.Reports.File(alice, (await Known(poster)).ID, Array.Empty<string>(), "a spammer", "spam", forward: true, Token);
+
+			Assert.False(report.Forwarded);
+			Assert.False((await DB.Default.Find<PrivaPub.Models.Social.Report>().OneAsync(report.ID, Token)).Forwarded);
+			Assert.Empty(await _harness.Outgoing(community.SharedInbox));
+			Assert.Empty(await _harness.Outgoing(poster.Id + "/inbox"));
+		}
+
+		[Fact]
+		public async Task Any_other_server_still_gets_the_instance_flag_and_a_lemmy_community_its_own()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var (community, _) = await OnLemmy();
+			// an account on a Mastodon (the peer as 127.0.0.1) that wrote in the community on the Lemmy, and elsewhere
+			var mastodonian = new RemoteActor(_harness.Peer, "masto");
+			await Runs("127.0.0.1", "mastodon");
+			var inCommunity = await Held(mastodonian, community.Id);
+			var elsewhere = await Held(mastodonian);
+			var instance = await _harness.Local.GetInstanceActor(Token);
+
+			var report = await _harness.Reports.File(alice, (await Known(mastodonian)).ID, new[] { inCommunity.ID, elsewhere.ID }, "spam", "spam", forward: true, Token);
+
+			Assert.True(report.Forwarded);
+			var toCommunity = Assert.Single(await _harness.Outgoing(community.SharedInbox));
+			Assert.Equal(inCommunity.ObjectURI, toCommunity["object"]!.GetValue<string>());
+			var toAuthor = Assert.Single(await _harness.Outgoing(mastodonian.Id + "/inbox"));
+			Assert.Equal(instance.Uri, toAuthor["actor"]!.GetValue<string>());
+			Assert.Equal(new[] { mastodonian.Id, inCommunity.ObjectURI, elsewhere.ObjectURI }.Order(),
+				toAuthor["object"]!.AsArray().Select(o => o!.GetValue<string>()).Order());
+			Assert.Null(toAuthor["to"]);
+		}
+
+		[Fact]
+		public async Task A_community_on_a_server_that_takes_no_service_reports_gets_nothing_new()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var community = new RemoteActor(_harness.Peer, "forum", _harness.Peer.B, type: "Group", sharedInbox: true);
+			var poster = new RemoteActor(_harness.Peer, "poster", _harness.Peer.B);
+			await Known(community);
+			var foreign = await Known(poster);
+			await Runs("localhost", "friendica");
+			var post = await Held(poster, community.Id);
+
+			var report = await _harness.Reports.File(alice, foreign.ID, new[] { post.ID }, "spam", "spam", forward: true, Token);
+
+			Assert.True(report.Forwarded);
+			Assert.Empty(await _harness.Outgoing(community.SharedInbox));
+			var flag = Assert.Single(await _harness.Outgoing(poster.Id + "/inbox"));
+			Assert.EndsWith("/peasants/privapub", flag["actor"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task Nobody_follows_the_reporter()
+		{
+			var follower = new RemoteActor(_harness.Peer, "follower");
+			var reporter = await _harness.Local.GetReporterActor(Token);
+
+			var result = await _harness.Deliver(follower, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{Origin(follower)}/follow/{Guid.NewGuid():N}", ["type"] = "Follow", ["actor"] = follower.Id, ["object"] = reporter.Uri
+			});
+
+			Assert.Equal(404, result.StatusCode);
+			Assert.False(await DB.Default.Find<Follower>().Match(f => f.ActorURI == follower.Id).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Federation/SharedInboxTests.cs

@@ -0,0 +1,50 @@
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Tests.Support;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	// one delivery a server: a reply to a follower's post goes to its server's shared inbox once, not also to the
+	// follower's own inbox (BookWyrm kept two copies of a post that reached both at once)
+	[Trait("Category", "Integration")]
+	public sealed class SharedInboxTests : IAsyncLifetime
+	{
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task A_reply_to_a_followers_post_reaches_its_server_once_through_the_shared_inbox()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var bob = new RemoteActor(_harness.Peer, "bob", sharedInbox: true);
+			await _harness.FollowedBy(alice, bob);
+			var path = $"/notes/{Guid.NewGuid():N}";
+			var noteId = new Uri(bob.Id).GetLeftPart(UriPartial.Authority) + path;
+			_harness.Peer.Serve(path, new JsonObject
+			{
+				["id"] = noteId, ["type"] = "Note", ["attributedTo"] = bob.Id, ["content"] = "<p>a question</p>",
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public"), ["published"] = DateTime.UtcNow.ToString("O")
+			}.ToJsonString());
+			var parent = await _harness.RemotePosts.StoreContext(noteId, 0, token);
+
+			var reply = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "an answer", InReplyTo = parent.ID }, token);
+
+			Assert.True(reply.Ok, reply.Error);
+			Assert.Single(await _harness.Outgoing(bob.SharedInbox), a => a["type"]!.GetValue<string>() == "Create");
+			Assert.Empty(await _harness.Outgoing(bob.Id + "/inbox"));
+		}
+	}
+}

PrivaPub.Tests/Federation/WallTests.cs

@@ -0,0 +1,213 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Rendering;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.Host.FederationHelpers;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Tests.Federation
+{
+	// walls (FEP-400e, Smithereen's; owner decision 2026-10-06): a persona's followers write on its wall, PrivaPub hosts what
+	// they write and tells the persona's followers with Add{Note}; the persona takes it off with Remove; an account elsewhere
+	// that tells of a post on its own wall has it shown to its followers here
+	[Trait("Category", "Integration")]
+	public sealed class WallTests : IAsyncLifetime
+	{
+		const string Public = "https://www.w3.org/ns/activitystreams#Public";
+
+		Harness _harness;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_harness = await Harness.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_harness != default)
+				await _harness.DisposeAsync();
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		// a public note by author, written on the wall of owner (whose actor and wall are given), served at its id
+		string WallNote(RemoteActor author, string ownerUri, string wall, string text, string inReplyTo = default, string to = Public)
+		{
+			var path = $"/notes/{Guid.NewGuid():N}";
+			var origin = new Uri(author.Id).GetLeftPart(UriPartial.Authority);
+			var note = new JsonObject
+			{
+				["id"] = origin + path, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+				["to"] = new JsonArray(to, ownerUri), ["published"] = DateTime.UtcNow.ToString("O"),
+				["target"] = new JsonObject { ["type"] = "Collection", ["id"] = wall, ["attributedTo"] = ownerUri }
+			};
+			if (inReplyTo != default)
+				note["inReplyTo"] = inReplyTo;
+			_harness.Peer.Serve(path, note.ToJsonString());
+			_notes[origin + path] = note;
+			return origin + path;
+		}
+
+		readonly Dictionary<string, JsonObject> _notes = new();
+
+		// as Smithereen sends it: the whole note, to the wall's owner
+		JsonObject Create(RemoteActor author, string noteId) => new()
+		{
+			["id"] = noteId + "/activityCreate", ["type"] = "Create", ["actor"] = author.Id, ["to"] = _notes[noteId]["to"]!.DeepClone(),
+			["object"] = _notes[noteId].DeepClone()
+		};
+
+		Task<PostEntity> Post(string objectUri) => DB.Default.Find<PostEntity>().Match(p => p.ObjectURI == objectUri).ExecuteFirstAsync(Token);
+
+		[Fact]
+		public void A_persona_names_its_wall_and_lets_its_followers_write_on_it()
+		{
+			var actor = ActivityPubRenderer.Actor(new LocalActor { Id = "a", UserName = "alice", BaseAddress = Harness.Base, Kind = PrivaPub.Models.Federation.LocalActorKind.Person });
+			var circle = ActivityPubRenderer.Actor(new LocalActor { Id = "c", UserName = "circle", BaseAddress = Harness.Base, Kind = PrivaPub.Models.Federation.LocalActorKind.Group, IsCircle = true });
+
+			Assert.Equal($"{Harness.Base}/peasants/alice/graffiti", actor["wall"]!.GetValue<string>());
+			Assert.Equal($"{Harness.Base}/peasants/alice/groupies", actor["privacySettings"]!["wallPosting"]!["allowedTo"]![0]!.GetValue<string>());
+			Assert.Equal(Public, actor["privacySettings"]!["wallPostVisibility"]!["allowedTo"]![0]!.GetValue<string>());
+			Assert.Contains(actor["@context"]!.AsArray(), c => c is JsonObject terms && terms["wall"]?["@id"]?.GetValue<string>() == "sm:wall");
+			Assert.Null(circle["wall"]);
+		}
+
+		[Fact]
+		public async Task A_followers_post_on_the_wall_is_hosted_shown_and_told_to_the_personas_followers()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var smuser = new RemoteActor(_harness.Peer, "smuser", wall: true);
+			await _harness.FollowedBy(alice, smuser);
+			var noteId = WallNote(smuser, alice.Uri, alice.Wall, "on alice's wall");
+
+			await _harness.Deliver(smuser, "/human-centipede", Create(smuser, noteId));
+
+			var post = await Post(noteId);
+			Assert.NotNull(post);
+			Assert.Equal((alice.Wall, alice.Uri, alice.Id), (post.WallURI, post.WallOwnerURI, post.WallOwnerAccountId));
+			Assert.True(await DB.Default.Find<TimelineEntry>().Match(e => e.AvatarId == alice.Id && e.PostId == post.ID).ExecuteAnyAsync(Token));
+			Assert.True(await DB.Default.Find<Notification>().Match(n => n.AvatarId == alice.Id && n.PostId == post.ID && n.Type == NotificationType.Mention).ExecuteAnyAsync(Token));
+			var add = Assert.Single(await _harness.Outgoing(_harness.Peer.A + "/inbox"), a => a["type"]!.GetValue<string>() == "Add");
+			Assert.Equal((alice.Uri, noteId, alice.Wall), (add["actor"]!.GetValue<string>(), add["object"]!.GetValue<string>(), add["target"]!["id"]!.GetValue<string>()));
+			Assert.Contains(await _harness.Outgoing(smuser.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Add");
+
+			Assert.True(await _harness.Walls.Remove(alice, post, Token));
+
+			Assert.Null(await Post(noteId));
+			var remove = Assert.Single(await _harness.Outgoing(_harness.Peer.A + "/inbox"), a => a["type"]!.GetValue<string>() == "Remove");
+			Assert.Equal((noteId, alice.Wall), (remove["object"]!.GetValue<string>(), remove["target"]!.GetValue<string>()));
+		}
+
+		[Fact]
+		public async Task A_wall_post_from_a_stranger_a_reply_or_a_quiet_one_is_refused()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var stranger = new RemoteActor(_harness.Peer, "stranger", wall: true);
+			var follower = new RemoteActor(_harness.Peer, "follower", wall: true);
+			await _harness.FollowedBy(alice, follower);
+			var fromStranger = WallNote(stranger, alice.Uri, alice.Wall, "from a stranger");
+			var reply = WallNote(follower, alice.Uri, alice.Wall, "a reply", inReplyTo: "https://elsewhere.example/notes/1");
+			var quiet = WallNote(follower, alice.Uri, alice.Wall, "quietly", to: follower.Id + "/followers");
+
+			await _harness.Deliver(stranger, "/human-centipede", Create(stranger, fromStranger));
+			await _harness.Deliver(follower, "/human-centipede", Create(follower, reply));
+			await _harness.Deliver(follower, "/human-centipede", Create(follower, quiet));
+
+			Assert.Null(await Post(fromStranger));
+			Assert.Null(await Post(reply));
+			Assert.Null(await Post(quiet));
+			Assert.DoesNotContain(await _harness.Outgoing(_harness.Peer.A + "/inbox"), a => a["type"]!.GetValue<string>() == "Add");
+		}
+
+		[Fact]
+		public async Task A_post_on_a_followed_accounts_wall_elsewhere_reaches_its_followers_here_until_it_is_taken_off()
+		{
+			var (_, alice) = await _harness.Persona("alice");
+			var owner = new RemoteActor(_harness.Peer, "owner", wall: true);
+			var writer = new RemoteActor(_harness.Peer, "writer");
+			await DB.Default.SaveAsync(new Following { AvatarId = alice.Id, TargetActorURI = owner.Id, TargetInboxURL = owner.Id + "/inbox", State = FollowState.Accepted }, Token);
+			var noteId = WallNote(writer, owner.Id, owner.Wall, "on the owner's wall");
+			// (kept before PrivaPub read walls: its document is read again when it names one)
+			await DB.Default.SaveAsync(new PrivaPub.Models.User.ForeignAvatar
+			{
+				ActorURI = owner.Id, UserName = owner.Name, PublicKeyId = owner.KeyId, PublicKey = owner.PublicKeyPem, InboxURL = owner.Id + "/inbox",
+				FollowersURL = owner.Id + "/followers", UpdatedAt = DateTime.UtcNow.AddDays(-2)
+			}, Token);
+
+			await _harness.Deliver(owner, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{owner.Id}/posts/{Guid.NewGuid():N}/activityAdd", ["type"] = "Add", ["actor"] = owner.Id, ["object"] = noteId,
+				["target"] = new JsonObject { ["type"] = "Collection", ["id"] = owner.Wall, ["attributedTo"] = owner.Id },
+				["to"] = new JsonArray(Public, owner.Id + "/followers")
+			});
+
+			var post = await Post(noteId);
+			Assert.NotNull(post);
+			Assert.Equal((writer.Id, owner.Id), (post.ActorURI, post.WallOwnerURI));
+			Assert.True(await DB.Default.Find<TimelineEntry>().Match(e => e.AvatarId == alice.Id && e.PostId == post.ID).ExecuteAnyAsync(Token));
+			Assert.False(await DB.Default.Find<RemoteFeatured>().Match(f => f.ObjectURI == noteId).ExecuteAnyAsync(Token));
+
+			await _harness.Deliver(owner, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{owner.Id}/posts/{Guid.NewGuid():N}/activityRemove", ["type"] = "Remove", ["actor"] = owner.Id, ["object"] = noteId, ["target"] = owner.Wall
+			});
+
+			Assert.Null(await Post(noteId));
+		}
+	}
+
+	[Trait("Category", "Integration")]
+	public sealed class WallCollectionTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		HttpClient _client;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_client = _host.Client();
+		}
+
+		public ValueTask DisposeAsync()
+		{
+			_client?.Dispose();
+			return ValueTask.CompletedTask;
+		}
+
+		[Fact]
+		public async Task The_wall_lists_the_personas_public_posts_and_what_others_wrote_on_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var persona = await _host.Persona(await _host.SignUp(), "wall");
+			var open = await _host.Publish(persona, "for everyone", PostVisibility.Public);
+			var quiet = await _host.Publish(persona, "for followers", PostVisibility.FollowersOnly);
+			var wall = persona.ActorUri() + "/graffiti";
+			var written = new PostEntity
+			{
+				ObjectURI = $"https://elsewhere.example/notes/{Guid.NewGuid():N}", ActorURI = "https://elsewhere.example/users/writer", IsFederatedCopy = true,
+				Visibility = PostVisibility.Public, WallURI = wall, WallOwnerURI = persona.ActorUri(), WallOwnerAccountId = persona.Id
+			};
+			await DB.Default.SaveAsync(written, token);
+
+			var collection = await _client.Fetch($"/peasants/{persona.UserName}/graffiti");
+			var page = await _client.Fetch($"/peasants/{persona.UserName}/graffiti?page=true");
+
+			Assert.Equal(HttpStatusCode.OK, collection.Status);
+			Assert.Equal((wall, 2), (collection.Json["id"]!.GetValue<string>(), collection.Json["totalItems"]!.GetValue<int>()));
+			var items = page.Json["orderedItems"]!.AsArray().Select(i => i!.GetValue<string>()).ToList();
+			Assert.Equal(new[] { written.ObjectURI, persona.ActorUri() + "/scribbles/" + open.ID }, items);
+			Assert.DoesNotContain(items, i => i.EndsWith(quiet.ID));
+		}
+	}
+}

PrivaPub.Tests/Fixtures/gotosocial/followers-only-reply-one-tag.json

@@ -0,0 +1 @@
+{"attributedTo":"https://gts.test/users/ines_gt59","cc":"https://privapub.test/peasants/flor_pp98","content":"\u003Cp\u003E\u003Cspan class=\u0022h-card\u0022\u003E\u003Ca href=\u0022https://privapub.test/@flor_pp98\u0022 class=\u0022u-url mention\u0022 rel=\u0022nofollow noreferrer noopener\u0022 target=\u0022_blank\u0022\u003E@\u003Cspan\u003Eflor_pp98\u003C/span\u003E\u003C/a\u003E\u003C/span\u003E bicycle the window bicycle tomorrow festival (p111)\u003C/p\u003E","contentMap":{"en":"\u003Cp\u003E\u003Cspan class=\u0022h-card\u0022\u003E\u003Ca href=\u0022https://privapub.test/@flor_pp98\u0022 class=\u0022u-url mention\u0022 rel=\u0022nofollow noreferrer noopener\u0022 target=\u0022_blank\u0022\u003E@\u003Cspan\u003Eflor_pp98\u003C/span\u003E\u003C/a\u003E\u003C/span\u003E bicycle the window bicycle tomorrow festival (p111)\u003C/p\u003E"},"id":"https://gts.test/users/ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY","inReplyTo":"https://privapub.test/peasants/flor_pp98/scribbles/6ac2beaf092dc0af8ce6035e","interactionPolicy":{"canAnnounce":{"automaticApproval":["https://gts.test/users/ines_gt59"]},"canLike":{"automaticApproval":["https://gts.test/users/ines_gt59","https://gts.test/users/ines_gt59/followers","https://privapub.test/peasants/flor_pp98"]},"canQuote":{"automaticApproval":["https://gts.test/users/ines_gt59"]},"canReply":{"automaticApproval":["https://gts.test/users/ines_gt59","https://gts.test/users/ines_gt59/followers","https://privapub.test/peasants/flor_pp98"]}},"published":"2026-10-04T21:02:31Z","replies":{"first":{"id":"https://gts.test/users/ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY/replies?page=true","next":"https://gts.test/users/ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY/replies?page=true\u0026only_other_accounts=false","partOf":"https://gts.test/users/ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY/replies","type":"CollectionPage"},"id":"https://gts.test/users/ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY/replies","type":"Collection"},"tag":{"href":"https://privapub.test/peasants/flor_pp98","name":"@flor_pp98@privapub.test","type":"Mention"},"to":"https://gts.test/users/ines_gt59/followers","type":"Note","url":"https://gts.test/@ines_gt59/statuses/01M44BKDVTWFAMAQ3YSBM4QETY"}

PrivaPub.Tests/Fixtures/pleroma/edited.json

@@ -0,0 +1,71 @@
+{
+	"actor": "https://pleroma.test/users/flor_pl97",
+	"attachment": [],
+	"attributedTo": "https://pleroma.test/users/flor_pl97",
+	"cc": [
+		"https://pleroma.test/users/flor_pl97/followers"
+	],
+	"content": "mountain late window map bright postcard (p10) (edited)",
+	"context": "https://pleroma.test/contexts/891653c5-91ba-43f3-b3ef-b066caa3fa4d",
+	"conversation": "https://pleroma.test/contexts/891653c5-91ba-43f3-b3ef-b066caa3fa4d",
+	"formerRepresentations": {
+		"orderedItems": [
+			{
+				"actor": "https://pleroma.test/users/flor_pl97",
+				"attachment": [],
+				"attributedTo": "https://pleroma.test/users/flor_pl97",
+				"cc": [
+					"https://pleroma.test/users/flor_pl97/followers"
+				],
+				"content": "tomorrow library garden bridge the festival bicycle together garden early quiet morning library the postcard tomorrow mountain the small rain postcard warm garden market map mountain map (p10)",
+				"contentMap": {
+					"en": "tomorrow library garden bridge the festival bicycle together garden early quiet morning library the postcard tomorrow mountain the small rain postcard warm garden market map mountain map (p10)"
+				},
+				"context": "https://pleroma.test/contexts/891653c5-91ba-43f3-b3ef-b066caa3fa4d",
+				"conversation": "https://pleroma.test/contexts/891653c5-91ba-43f3-b3ef-b066caa3fa4d",
+				"published": "2026-10-05T00:49:58.860071Z",
+				"repliesCount": 2,
+				"source": {
+					"content": "tomorrow library garden bridge the festival bicycle together garden early quiet morning library the postcard tomorrow mountain the small rain postcard warm garden market map mountain map (p10)",
+					"mediaType": "text/plain"
+				},
+				"summary": "",
+				"tag": [],
+				"to": [
+					"https://www.w3.org/ns/activitystreams#Public"
+				],
+				"type": "Note"
+			}
+		],
+		"totalItems": 1,
+		"type": "OrderedCollection"
+	},
+	"id": "https://pleroma.test/objects/6101c4fd-ed46-461c-a3fe-9742852f47da",
+	"published": "2026-10-05T00:49:58.860071Z",
+	"replies": {
+		"first": {
+			"id": "https://pleroma.test/objects/6101c4fd-ed46-461c-a3fe-9742852f47da/replies?page=true",
+			"orderedItems": [
+				"https://pleroma.test/objects/b7b7c066-51a8-46d1-8919-07b87f158887",
+				"https://privapub.test/peasants/vera_pp40/scribbles/6ac2f4520c61eaf3ab241d35"
+			],
+			"partOf": "https://pleroma.test/objects/6101c4fd-ed46-461c-a3fe-9742852f47da/replies",
+			"type": "OrderedCollectionPage"
+		},
+		"id": "https://pleroma.test/objects/6101c4fd-ed46-461c-a3fe-9742852f47da/replies",
+		"totalItems": 2,
+		"type": "OrderedCollection"
+	},
+	"repliesCount": 2,
+	"source": {
+		"content": "mountain late window map bright postcard (p10) (edited)",
+		"mediaType": "text/plain"
+	},
+	"summary": "",
+	"tag": [],
+	"to": [
+		"https://www.w3.org/ns/activitystreams#Public"
+	],
+	"type": "Note",
+	"updated": "2026-10-05T00:52:40.105051Z"
+}

PrivaPub.Tests/Http/BackupEndpointTests.cs

@@ -0,0 +1,200 @@
+using MongoDB.Entities;
+
+using PrivaPub.ClientModels;
+using PrivaPub.Infrastructure.Backup;
+using PrivaPub.Models.User;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Formats.Tar;
+using System.Net;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// The administrator's page backs up, downloads, uploads and restores (owner decision 2026-10-07): only an
+	// administrator the database still says is one; a download and a restore ask for the password again, a restore for
+	// the host typed out; an upload resumes where it stopped, and one that would write outside its backup is refused.
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class BackupEndpointTests : IAsyncLifetime
+	{
+		const string Base = "/clientapi/admin/backups";
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync()
+		{
+			RestoreMarker.Clear(_host?.Get<Backups>().Root ?? Path.GetTempPath());
+			return ValueTask.CompletedTask;
+		}
+
+		async Task<string> BackedUp(HttpClient admin)
+		{
+			var before = _host.Get<Backups>().List().Select(b => b.Id).ToHashSet();
+			Assert.Equal(HttpStatusCode.Accepted, (await admin.PostAsync(Base, null, Token)).StatusCode);
+			var made = default(string);
+			Assert.True(await Wait(async () =>
+			{
+				var list = (await admin.GetFromJsonAsync<JsonObject>(Base, Token))!;
+				made = list["backups"]!.AsArray().Select(b => b!["id"]!.GetValue<string>()).FirstOrDefault(id => !before.Contains(id));
+				return made != default && list["running"] is null;
+			}), "the backup was never made");
+			return made;
+		}
+
+		static async Task<bool> Wait(Func<Task<bool>> done)
+		{
+			for (var i = 0; i < 120; i++)
+			{
+				if (await done())
+					return true;
+				await Task.Delay(250, Token);
+			}
+			return false;
+		}
+
+		[Fact]
+		public async Task Only_an_administrator_the_database_still_knows()
+		{
+			var root = await _host.SignUp("plain");
+			using (var plain = _host.As(root.Jwt))
+				Assert.Equal(HttpStatusCode.Forbidden, (await plain.GetAsync(Base, Token)).StatusCode);
+
+			var admin = await _host.Admin();
+			using var client = _host.As(admin.Jwt);
+			Assert.Equal(HttpStatusCode.OK, (await client.GetAsync(Base, Token)).StatusCode);
+			await DB.Default.Update<RootUser>().MatchID(admin.Id).Modify(u => u.Policies, [Policies.IsUser]).ExecuteAsync(Token);
+			Assert.Equal(HttpStatusCode.Forbidden, (await client.GetAsync(Base, Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.Forbidden, (await client.PostAsync(Base, null, Token)).StatusCode);
+		}
+
+		[Fact]
+		public async Task A_backup_is_made_downloaded_whole_or_in_part_and_uploaded_again()
+		{
+			var admin = await _host.Admin();
+			using var client = _host.As(admin.Jwt);
+			var id = await BackedUp(client);
+			var listed = (await client.GetFromJsonAsync<JsonObject>(Base, Token))!;
+			Assert.Equal("privapub.test", listed["host"]!.GetValue<string>());
+			Assert.Equal("manual", listed["backups"]!.AsArray().Single(b => b!["id"]!.GetValue<string>() == id)!["kind"]!.GetValue<string>());
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await client.PostAsJsonAsync($"{Base}/{id}/ticket", new { password = "wrong" }, Token)).StatusCode);
+			var ticket = (await (await client.PostAsJsonAsync($"{Base}/{id}/ticket", new { password = admin.Password }, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!;
+			var url = ticket["url"]!.GetValue<string>();
+
+			// a plain link: no token needed, the ticket is the credential
+			using var anonymous = _host.Client();
+			var whole = await anonymous.GetAsync(url, Token);
+			Assert.Equal(HttpStatusCode.OK, whole.StatusCode);
+			var bytes = await whole.Content.ReadAsByteArrayAsync(Token);
+			Assert.Equal(ticket["bytes"]!.GetValue<long>(), bytes.Length);
+			Assert.Equal(bytes.Length, whole.Content.Headers.ContentLength);
+			var names = new List<string>();
+			await using (var reader = new TarReader(new MemoryStream(bytes)))
+				while (await reader.GetNextEntryAsync(cancellationToken: Token) is { } entry)
+					names.Add(entry.Name);
+			Assert.Contains($"{id}/manifest.json", names);
+			Assert.Contains($"{id}/db/Avatar.jsonl.gz", names);
+
+			var part = new HttpRequestMessage(HttpMethod.Get, url);
+			part.Headers.Range = new RangeHeaderValue(700, 2747);
+			var partial = await anonymous.SendAsync(part, Token);
+			Assert.Equal(HttpStatusCode.PartialContent, partial.StatusCode);
+			Assert.Equal($"bytes 700-2747/{bytes.Length}", partial.Content.Headers.ContentRange!.ToString());
+			Assert.Equal(bytes.AsSpan(700, 2048).ToArray(), await partial.Content.ReadAsByteArrayAsync(Token));
+			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.GetAsync($"{Base}/download/{new string('0', 64)}", Token)).StatusCode);
+
+			// gone, then uploaded again in three pieces, one sent at the wrong place and refused with where to go on
+			Assert.Equal(HttpStatusCode.OK, (await client.DeleteAsync($"{Base}/{id}", Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.NotFound, (await client.DeleteAsync($"{Base}/{id}", Token)).StatusCode);
+			var upload = (await (await client.PostAsync($"{Base}/uploads", null, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!["id"]!.GetValue<string>();
+			var third = bytes.Length / 3;
+			Assert.Equal(HttpStatusCode.OK, (await Piece(client, upload, 0, bytes[..third])).StatusCode);
+			var gap = await Piece(client, upload, third + 10, bytes[(third + 10)..]);
+			Assert.Equal(HttpStatusCode.Conflict, gap.StatusCode);
+			Assert.Equal(third, (await gap.Content.ReadFromJsonAsync<JsonObject>(Token))!["received"]!.GetValue<long>());
+			Assert.Equal(HttpStatusCode.OK, (await Piece(client, upload, third, bytes[third..(2 * third)])).StatusCode);
+			Assert.Equal(HttpStatusCode.OK, (await Piece(client, upload, 2 * third, bytes[(2 * third)..])).StatusCode);
+			var finished = await client.PostAsync($"{Base}/uploads/{upload}/finish", null, Token);
+			Assert.Equal(HttpStatusCode.OK, finished.StatusCode);
+			Assert.Equal("uploaded", (await finished.Content.ReadFromJsonAsync<JsonObject>(Token))!["kind"]!.GetValue<string>());
+			Assert.Empty(await _host.Get<Backups>().Verify(id, Token));
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await client.PostAsync($"{Base}/uploads/{upload}/finish", null, Token)).StatusCode);
+			_host.Get<Backups>().Delete(id);
+		}
+
+		Task<HttpResponseMessage> Piece(HttpClient client, string upload, long offset, byte[] bytes) =>
+			client.PutAsync($"{Base}/uploads/{upload}?offset={offset}", new ByteArrayContent(bytes), Token);
+
+		[Theory]
+		[InlineData("escape")]
+		[InlineData("link")]
+		[InlineData("elsewhere")]
+		[InlineData("junk")]
+		public async Task An_upload_that_is_not_a_plain_backup_is_refused_and_leaves_nothing(string how)
+		{
+			var admin = await _host.Admin();
+			using var client = _host.As(admin.Jwt);
+			const string id = "20260101-000000-manual";
+			var tar = new MemoryStream();
+			if (how == "junk")
+				tar.Write("not a tar at all, not even close"u8);
+			else
+				await using (var writer = new TarWriter(tar, TarEntryFormat.Pax, leaveOpen: true))
+				{
+					await writer.WriteEntryAsync(new PaxTarEntry(TarEntryType.RegularFile, $"{id}/manifest.json") { DataStream = new MemoryStream("{}"u8.ToArray()) }, Token);
+					await writer.WriteEntryAsync(how switch
+					{
+						"escape" => new PaxTarEntry(TarEntryType.RegularFile, $"{id}/../../evil") { DataStream = new MemoryStream("x"u8.ToArray()) },
+						"link" => new PaxTarEntry(TarEntryType.SymbolicLink, $"{id}/media/x.jpg") { LinkName = "/etc/passwd" },
+						_ => new PaxTarEntry(TarEntryType.RegularFile, "20260101-000000-nightly/db/Post.jsonl.gz") { DataStream = new MemoryStream("x"u8.ToArray()) }
+					}, Token);
+				}
+			var upload = (await (await client.PostAsync($"{Base}/uploads", null, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!["id"]!.GetValue<string>();
+			Assert.Equal(HttpStatusCode.OK, (await Piece(client, upload, 0, tar.ToArray())).StatusCode);
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await client.PostAsync($"{Base}/uploads/{upload}/finish", null, Token)).StatusCode);
+			var root = _host.Get<Backups>().Root;
+			Assert.False(Directory.Exists(Path.Combine(root, id)));
+			Assert.False(Directory.Exists(Path.Combine(root, id + ServerBackup.PartialSuffix)));
+			Assert.False(File.Exists(Path.Combine(root, "..", "evil")));
+		}
+
+		// asked for: written for the next start (the test host has no watcher to stop it, and the marker is taken away)
+		[Fact]
+		public async Task A_restore_asks_for_the_password_and_the_host_typed_out()
+		{
+			var admin = await _host.Admin();
+			using var client = _host.As(admin.Jwt);
+			var id = await BackedUp(client);
+			var root = _host.Get<Backups>().Root;
+			try
+			{
+				Assert.Equal(HttpStatusCode.UnprocessableEntity, (await client.PostAsJsonAsync($"{Base}/{id}/restore", new { password = "wrong", host = "privapub.test" }, Token)).StatusCode);
+				Assert.Equal(HttpStatusCode.UnprocessableEntity, (await client.PostAsJsonAsync($"{Base}/{id}/restore", new { password = admin.Password, host = "elsewhere.test" }, Token)).StatusCode);
+				Assert.Null(RestoreMarker.Read(root));
+
+				Assert.Equal(HttpStatusCode.Accepted, (await client.PostAsJsonAsync($"{Base}/{id}/restore", new { password = admin.Password, host = "PrivaPub.test" }, Token)).StatusCode);
+				var marker = RestoreMarker.Read(root);
+				Assert.Equal((id, "pending", admin.UserName), (marker.Backup, marker.State, marker.RequestedBy));
+				Assert.Equal(id, (await client.GetFromJsonAsync<JsonObject>(Base, Token))!["waiting"]!["backup"]!.GetValue<string>());
+				Assert.Equal(HttpStatusCode.Conflict, (await client.DeleteAsync($"{Base}/{id}", Token)).StatusCode);
+			}
+			finally
+			{
+				RestoreMarker.Clear(root);
+				_host.Get<Backups>().Delete(id);
+			}
+		}
+	}
+}

PrivaPub.Tests/Http/ClientApiGroupsTests.cs

@@ -202,6 +202,51 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(circle["url"]!.GetValue<string>(), accept["actor"]!.GetValue<string>());
 		}
 
+		// its owner sees who is in the circle and who asks to join, declines one request and takes members out; nobody else
+		// sees them
+		[Fact]
+		public async Task An_owner_sees_the_members_and_requests_declines_one_and_removes_members()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (owner, circle, member) = await CircleWithRemoteMember();
+			var groupId = circle["id"]!.GetValue<string>();
+			var joiner = await NewPersona("joiner");
+			using (var joining = _host.As(joiner.Root.Jwt))
+				Assert.True((await joining.PostJson("/clientapi/group/join", new { avatarId = joiner.Id, invitationCode = circle["invitationCode"]!.GetValue<string>() })).IsSuccessStatusCode);
+			var asker = new RemoteActor(_peer, "asker");
+			await _host.Follow(asker, _peer.A, circle["userName"]!.GetValue<string>());
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			using var client = _host.As(owner.Root.Jwt);
+			async Task<List<JsonNode>> Members(HttpClient as_, string avatarId)
+			{
+				var response = await as_.GetAsync($"/clientapi/group/members?avatarId={avatarId}&groupId={groupId}", token);
+				return response.IsSuccessStatusCode ? (await response.JsonItems()).ToList() : null;
+			}
+
+			var listed = await Members(client, owner.Id);
+			using var joinerClient = _host.As(joiner.Root.Jwt);
+			var forJoiner = await Members(joinerClient, joiner.Id);
+			var declined = await client.PostJson("/clientapi/group/reject", new { avatarId = owner.Id, groupId, memberActorURI = asker.Id });
+			var removedRemote = await client.PostJson("/clientapi/group/remove", new { avatarId = owner.Id, groupId, memberActorURI = member.Id });
+			var removedLocal = await client.PostJson("/clientapi/group/remove", new { avatarId = owner.Id, groupId, memberActorURI = joiner.ActorUri() });
+			var removedOwner = await client.PostJson("/clientapi/group/remove", new { avatarId = owner.Id, groupId, memberActorURI = owner.ActorUri() });
+
+			Assert.Null(forJoiner);
+			Assert.Equal(4, listed.Count);
+			Assert.Contains(listed, m => m!["actorUri"]!.GetValue<string>() == owner.ActorUri() && m["role"]!.GetValue<string>() == "owner" && m["isLocal"]!.GetValue<bool>());
+			Assert.Contains(listed, m => m!["actorUri"]!.GetValue<string>() == joiner.ActorUri() && !m["isPending"]!.GetValue<bool>());
+			Assert.Contains(listed, m => m!["actorUri"]!.GetValue<string>() == member.Id && !m["isPending"]!.GetValue<bool>() && !m["isLocal"]!.GetValue<bool>());
+			Assert.Contains(listed, m => m!["actorUri"]!.GetValue<string>() == asker.Id && m["isPending"]!.GetValue<bool>());
+			Assert.True(declined.IsSuccessStatusCode);
+			Assert.True(removedRemote.IsSuccessStatusCode);
+			Assert.True(removedLocal.IsSuccessStatusCode);
+			Assert.Equal(HttpStatusCode.BadRequest, removedOwner.StatusCode);
+			Assert.Equal(new[] { owner.Id }, (await Stored(circle)).Members.Select(m => m.AvatarId));
+			Assert.False(await DB.Default.Find<Follower>().Match(f => f.LocalActorId == groupId && f.ActorURI != owner.ActorUri()).ExecuteAnyAsync(token));
+			Assert.Contains(await Jobs.Deliveries(asker.Id + "/inbox", since, token), d => d["type"]!.GetValue<string>() == "Reject");
+			Assert.Contains(await Jobs.Deliveries(member.Id + "/inbox", since, token), d => d["type"]!.GetValue<string>() == "Reject");
+		}
+
 		[Fact]
 		public async Task A_circle_is_never_found()
 		{

PrivaPub.Tests/Http/ClientApiPersonasTests.cs

@@ -103,7 +103,7 @@ namespace PrivaPub.Tests.Http
 			var response = await Insert(root, new { userName, name = userName, biography = "testing" });
 
 			Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
-			Assert.Contains("already take", (await response.JsonBody())["errorMessage"]!.GetValue<string>());
+			Assert.Contains("already taken", (await response.JsonBody())["errorMessage"]!.GetValue<string>());
 			Assert.Empty(await Listed(root));
 		}
 

PrivaPub.Tests/Http/FederationGetTests.cs

@@ -101,6 +101,51 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal("Application", instance.Json["type"]!.GetValue<string>());
 		}
 
+		// PieFed reads the inbox it sends a community's announces to from the Application at a peer's root
+		[Fact]
+		public async Task The_instance_actor_answers_at_the_root_for_activitypub_only()
+		{
+			var root = await _client.Fetch("/");
+			var browser = await _client.Fetch("/", Browser);
+
+			Assert.Equal(HttpStatusCode.OK, root.Status);
+			Assert.Equal("Application", root.Json["type"]!.GetValue<string>());
+			Assert.Equal($"{Base}/peasants/privapub", root.Json["id"]!.GetValue<string>());
+			Assert.Equal($"{Base}/peasants/privapub/mouth", root.Json["inbox"]!.GetValue<string>());
+			Assert.Equal(HttpStatusCode.NotFound, browser.Status);
+		}
+
+		// Lemmy takes a report only from a Person, a Service or an Organization, whose document names its preferredUsername,
+		// inbox, outbox and key; a browser gets the document too, as from the instance actor: the reporter has no page
+		[Fact]
+		public async Task The_reporter_is_a_service_with_an_inbox_an_outbox_and_its_own_key()
+		{
+			var fetched = await _client.Fetch("/peasants/privapub_reports");
+			var browser = await _client.Fetch("/peasants/privapub_reports", Browser);
+			var outbox = await _client.Fetch("/peasants/privapub_reports/anus");
+			var instance = await _client.Fetch("/peasants/privapub");
+
+			Assert.Equal(HttpStatusCode.OK, fetched.Status);
+			var actor = fetched.Json;
+			var id = $"{Base}/peasants/privapub_reports";
+			Assert.Equal(id, actor["id"]!.GetValue<string>());
+			Assert.Equal("Service", actor["type"]!.GetValue<string>());
+			Assert.Equal("privapub_reports", actor["preferredUsername"]!.GetValue<string>());
+			Assert.Equal(id + "/mouth", actor["inbox"]!.GetValue<string>());
+			Assert.Equal(id + "/anus", actor["outbox"]!.GetValue<string>());
+			Assert.Equal(id, actor["url"]!.GetValue<string>());
+			Assert.Equal(id + "#main-key", actor["publicKey"]!["id"]!.GetValue<string>());
+			Assert.Equal(id, actor["publicKey"]!["owner"]!.GetValue<string>());
+			Assert.NotEqual(instance.Json["publicKey"]!["publicKeyPem"]!.GetValue<string>(), actor["publicKey"]!["publicKeyPem"]!.GetValue<string>());
+			Assert.False(actor["discoverable"]!.GetValue<bool>());
+			Assert.Null(actor["wall"]);
+			Assert.Null(actor["implements"]);
+			Assert.Equal(HttpStatusCode.OK, browser.Status);
+			Assert.Equal("Service", browser.Json["type"]!.GetValue<string>());
+			Assert.Equal(HttpStatusCode.OK, outbox.Status);
+			Assert.Equal(0, outbox.Json["totalItems"]!.GetValue<int>());
+		}
+
 		[Fact]
 		public async Task Users_moves_permanently_to_peasants_and_unknown_actors_are_404()
 		{
@@ -142,7 +187,9 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(ActivityJson, outbox.MediaType);
 			Assert.Equal("OrderedCollection", outbox.Json["type"]!.GetValue<string>());
 			Assert.Equal(persona.ActorUri() + "/anus", outbox.Json["id"]!.GetValue<string>());
-			Assert.Equal(22, outbox.Json["totalItems"]!.GetValue<int>());
+			// statuses_count, as Mastodon counts it: everything but the DM, the deleted post and the copy of a remote post,
+			// the followers-only and located posts and the boost included; only the public posts are listed
+			Assert.Equal(24, outbox.Json["totalItems"]!.GetValue<int>());
 			Assert.Null(outbox.Json["orderedItems"]);
 			var first = outbox.Json["first"]!.GetValue<string>();
 			Assert.Equal(persona.ActorUri() + "/anus?page=true", first);
@@ -168,7 +215,7 @@ namespace PrivaPub.Tests.Http
 			var announce = items[0];
 			Assert.Equal("Announce", announce["type"]!.GetValue<string>());
 			Assert.Equal(reblog.ObjectURI, announce["id"]!.GetValue<string>());
-			Assert.Equal($"{persona.ActorUri()}/grunts/announce-{boosted.ID}", announce["id"]!.GetValue<string>());
+			Assert.Equal($"{persona.ActorUri()}/grunts/announce-{reblog.ID}", announce["id"]!.GetValue<string>());
 			Assert.Equal(boosted.ObjectURI, announce["object"]!.GetValue<string>());
 			Assert.Equal(persona.ActorUri(), announce["actor"]!.GetValue<string>());
 
@@ -221,7 +268,7 @@ namespace PrivaPub.Tests.Http
 			Assert.DoesNotContain(pending, followers.Text);
 			Assert.Equal(HttpStatusCode.OK, following.Status);
 			Assert.Equal(persona.ActorUri() + "/stalking", following.Json["id"]!.GetValue<string>());
-			Assert.Equal(0, following.Json["totalItems"]!.GetValue<int>());
+			Assert.Equal(1, following.Json["totalItems"]!.GetValue<int>());//counted, as following_count says, never listed
 			Assert.DoesNotContain(friend.UserName, following.Text);
 		}
 
@@ -434,7 +481,7 @@ namespace PrivaPub.Tests.Http
 			string Path(string id) => $"/peasants/{persona.UserName}/grunts/{id}";
 
 			var create = await _client.Fetch(Path($"create-{post.ID}"));
-			var announce = await _client.Fetch(Path($"announce-{original.ID}"));
+			var announce = await _client.Fetch(Path($"announce-{reblog.ID}"));
 
 			Assert.Equal(HttpStatusCode.OK, create.Status);
 			Assert.Equal(ActivityJson, create.MediaType);
@@ -449,7 +496,8 @@ namespace PrivaPub.Tests.Http
 
 			foreach (var unknown in new[] { $"create-{followersOnly.ID}", $"create-{Guid.NewGuid():N}"[..31], $"announce-{post.ID}", $"like-{post.ID}", "x" })
 				Assert.Equal(HttpStatusCode.NotFound, (await _client.Fetch(Path(unknown))).Status);
-			Assert.Equal(HttpStatusCode.NotFound, (await _client.Fetch($"/peasants/{friend.UserName}/grunts/announce-{original.ID}")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await _client.Fetch(Path($"announce-{original.ID}"))).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await _client.Fetch($"/peasants/{friend.UserName}/grunts/announce-{reblog.ID}")).Status);
 		}
 
 		[Fact]
@@ -490,7 +538,7 @@ namespace PrivaPub.Tests.Http
 		}
 
 		[Fact]
-		public async Task Secure_mode_refuses_unsigned_gets_except_for_the_instance_actor()
+		public async Task Secure_mode_refuses_unsigned_gets_except_for_the_servers_own_actors()
 		{
 			var secure = await SecureModeHost.Shared();
 			using var client = secure.Client();
@@ -516,6 +564,10 @@ namespace PrivaPub.Tests.Http
 			var instance = await client.Fetch("/peasants/privapub");
 			Assert.Equal(HttpStatusCode.OK, instance.Status);
 			Assert.Equal("Application", instance.Json["type"]!.GetValue<string>());
+			var reporter = await client.Fetch("/peasants/privapub_reports");
+			Assert.Equal(HttpStatusCode.OK, reporter.Status);
+			Assert.Equal("Service", reporter.Json["type"]!.GetValue<string>());
+			Assert.Equal(HttpStatusCode.OK, (await client.Fetch("/")).Status);
 			foreach (var path in paths[..^1])
 				Assert.True((await client.Fetch(reader.SignedGet(path))).Status == HttpStatusCode.OK, $"{path} refused a signed GET");
 			// a browser is not asked for a signature: it is only sent to the public pages

PrivaPub.Tests/Http/InstanceLocationTests.cs

@@ -0,0 +1,291 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Jobs;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Where a server is, on the public instance API: where it was located (city, coordinates and network, whatever its size),
+	// only the CDN's name for a CDN-fronted one, the batch form, and this server itself.
+	[Trait("Category", "Integration")]
+	public sealed class InstanceLocationTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		static async Task<string> Instance(int users, InstanceGeo geo, string name = "located")
+		{
+			var host = $"{name}{Guid.NewGuid():N}.example";
+			await DB.Default.SaveAsync(new RemoteInstance { Host = host, Software = "mastodon", UsersTotal = users, Geo = geo }, Token);
+			return host;
+		}
+
+		static InstanceGeo Milan(string cdn = default) => new()
+		{
+			Country = "IT",
+			City = "Milan",
+			Latitude = 45.5,
+			Longitude = 9.2,
+			Asn = 12345,
+			AsnOrg = "Example Hosting",
+			Cdn = cdn,
+			Ipv6 = true,
+			Source = "DB-IP Lite 2026-10",
+			LocatedAt = DateTime.UtcNow.AddDays(-2)
+		};
+
+		async Task<JsonNode> Geo(string host) => (await _host.Client().Get($"/api/privapub/v1/instances/{host}")).Ok().Body["geo"];
+
+		[Fact]
+		public async Task A_located_server_shows_its_city_coordinates_and_network()
+		{
+			var geo = await Geo(await Instance(50, Milan()));
+
+			Assert.Equal("city", geo.Text("precision"));
+			Assert.Equal(("IT", "Milan", "Example Hosting"), (geo.Text("country"), geo.Text("city"), geo.Text("network")));
+			Assert.Equal(45.5, geo["latitude"]!.GetValue<double>());
+			Assert.Equal(9.2, geo["longitude"]!.GetValue<double>());
+			Assert.Equal("DB-IP Lite 2026-10", geo.Text("source"));
+			Assert.NotNull(geo.Text("located_at"));
+			Assert.Null(geo["asn"]);
+			Assert.Null(geo["ipv6"]);
+		}
+
+		[Fact]
+		public async Task A_one_user_server_shows_its_city_too()
+		{
+			var geo = await Geo(await Instance(1, Milan()));
+
+			Assert.Equal("city", geo.Text("precision"));
+			Assert.Equal(("IT", "Milan", "Example Hosting"), (geo.Text("country"), geo.Text("city"), geo.Text("network")));
+			Assert.Equal(45.5, geo["latitude"]!.GetValue<double>());
+		}
+
+		[Fact]
+		public async Task A_server_located_only_to_its_country_shows_the_country()
+		{
+			var geo = await Geo(await Instance(50, new InstanceGeo { Country = "IT", Source = "DB-IP Lite 2026-10", LocatedAt = DateTime.UtcNow }));
+
+			Assert.Equal("country", geo.Text("precision"));
+			Assert.Equal("IT", geo.Text("country"));
+			Assert.Null(geo["city"]);
+			Assert.Null(geo["latitude"]);
+		}
+
+		[Fact]
+		public async Task A_cdn_fronted_server_shows_only_its_cdn()
+		{
+			var geo = await Geo(await Instance(5000, Milan(cdn: "Cloudflare")));
+
+			Assert.Equal("cdn", geo.Text("precision"));
+			Assert.Equal("Cloudflare", geo.Text("cdn"));
+			Assert.Null(geo["country"]);
+			Assert.Null(geo["latitude"]);
+			Assert.Null(geo["network"]);
+		}
+
+		[Fact]
+		public async Task An_unlocated_server_has_no_place()
+		{
+			Assert.Null(await Geo(await Instance(50, default)));
+		}
+
+		[Fact]
+		public async Task The_provenance_of_a_post_carries_the_same_projection()
+		{
+			var host = await Instance(3, Milan());
+			var described = (await _host.Client().Get($"/api/privapub/v1/instances/{host}")).Ok().Body;
+
+			Assert.Equal("city", described["geo"].Text("precision"));
+			Assert.Equal(described["geo"]!.ToJsonString(), (await Geo(host))!.ToJsonString());
+		}
+
+		[Fact]
+		public async Task Several_servers_answer_at_once_in_the_order_asked_without_the_unknown_ones()
+		{
+			var big = await Instance(50, Milan(), "big");
+			var small = await Instance(3, Milan(), "small");
+			var unknown = $"unknown{Guid.NewGuid():N}.example";
+
+			var answer = (await _host.Client().Get($"/api/privapub/v1/instances?host[]={small}&host[]={unknown}&host[]={big.ToUpperInvariant()}&host[]={small}")).Ok();
+			var hosts = answer.Body!.AsArray().Select(i => i.Text("host")).ToList();
+
+			Assert.Equal(new[] { small, big }, hosts);
+			Assert.Equal("city", answer.Body![0]["geo"].Text("precision"));
+			Assert.Equal("city", answer.Body![1]["geo"].Text("precision"));
+			Assert.Empty((await _host.Client().Get("/api/privapub/v1/instances")).Ok().Body!.AsArray());
+		}
+
+		[Fact]
+		public async Task At_most_forty_servers_answer_at_once()
+		{
+			var hosts = new List<string>();
+			for (var i = 0; i < 42; i++)
+				hosts.Add(await Instance(1, default, "many"));
+
+			var answer = (await _host.Client().Get("/api/privapub/v1/instances?" + string.Join("&", hosts.Select(h => "host[]=" + h)))).Ok();
+
+			Assert.Equal(hosts.Take(40), answer.Body!.AsArray().Select(i => i.Text("host")));
+		}
+
+		[Fact]
+		public async Task This_server_describes_itself()
+		{
+			var self = (await _host.Client().Get($"/api/privapub/v1/instances/{PrivaPubHost.Host}")).Ok().Body;
+
+			Assert.Equal(PrivaPubHost.Host, self.Text("host"));
+			Assert.Equal("privapub", self.Text("software"));
+			Assert.Equal("activitypub", Assert.Single(self["protocols"]!.AsArray())!.GetValue<string>());
+			Assert.Null(self["geo"]);
+			var batch = (await _host.Client().Get($"/api/privapub/v1/instances?host[]={PrivaPubHost.Host}")).Ok().Body!.AsArray();
+			Assert.Equal("privapub", Assert.Single(batch).Text("software"));
+		}
+
+		[Fact]
+		public async Task The_owner_may_place_this_server()
+		{
+			var placed = await SelfPlacedHost.Shared();
+
+			var geo = (await placed.Client().Get($"/api/privapub/v1/instances/{PrivaPubHost.Host}")).Ok().Body["geo"];
+
+			Assert.Equal("city", geo.Text("precision"));
+			Assert.Equal(("IT", "Milan", "configured"), (geo.Text("country"), geo.Text("city"), geo.Text("source")));
+			Assert.Equal(45.5, geo["latitude"]!.GetValue<double>());
+			Assert.Equal(9.2, geo["longitude"]!.GetValue<double>());
+		}
+
+		static string WeeksAgo(int weeks) => PrivaPub.Federation.Objects.InstanceDescriber.Week(DateTime.UtcNow.AddDays(-7 * weeks));
+
+		static Task Snapshot(string host, int weeksAgo, string cdn = default, string cdnDomain = default, string city = default, double? latitude = default,
+			double? longitude = default, string country = default) =>
+			DB.Default.SaveAsync(new RemoteInstanceSnapshot
+			{
+				Host = host, Week = WeeksAgo(weeksAgo), TakenAt = DateTime.UtcNow.AddDays(-7 * weeksAgo), Reachable = true, Software = "mastodon", UsersTotal = 3,
+				Cdn = cdn, CdnDomain = cdnDomain, CdnSource = cdn == default ? default : "ranges", Country = country, City = city, Latitude = latitude, Longitude = longitude
+			}, Token);
+
+		[Fact]
+		public async Task A_cdn_fronted_server_names_its_cdn_and_where_it_was_before_it()
+		{
+			var host = await Instance(3, new InstanceGeo
+			{
+				Country = "US", City = "San Francisco", Latitude = 37.8, Longitude = -122.4, Cdn = "Cloudflare", CdnDomain = "cloudflare.com", CdnSource = "ranges",
+				Source = "DB-IP Lite 2026-10", LocatedAt = DateTime.UtcNow
+			}, "fronted");
+			await Snapshot(host, 3, city: "Berlin", latitude: 52.5, longitude: 13.4, country: "DE");
+			await Snapshot(host, 2, city: "Hamburg", latitude: 53.6, longitude: 10.0, country: "DE");
+			await Snapshot(host, 1, cdn: "Cloudflare", cdnDomain: "cloudflare.com", city: "San Francisco", latitude: 37.8, longitude: -122.4, country: "US");
+
+			var geo = await Geo(host);
+
+			Assert.Equal(("cdn", "Cloudflare", "cloudflare.com", "ranges"), (geo.Text("precision"), geo.Text("cdn"), geo.Text("cdn_domain"), geo.Text("cdn_source")));
+			Assert.Null(geo["latitude"]);
+			Assert.Equal((WeeksAgo(2), "Hamburg", "DE"), (geo["before_cdn"].Text("week"), geo["before_cdn"].Text("city"), geo["before_cdn"].Text("country")));
+			Assert.Equal(53.6, geo["before_cdn"]!["latitude"]!.GetValue<double>());
+		}
+
+		[Fact]
+		public async Task A_server_history_is_weekly_newest_first_and_a_cdn_hides_its_place()
+		{
+			var host = await Instance(3, Milan(), "historic");
+			await Snapshot(host, 2, city: "Milan", latitude: 45.5, longitude: 9.2, country: "IT");
+			await Snapshot(host, 1, cdn: "Fastly", cdnDomain: "fastly.com", city: "Frankfurt", latitude: 50.1, longitude: 8.7, country: "DE");
+
+			var weeks = (await _host.Client().Get($"/api/privapub/v1/instances/{host}/history")).Ok().Body!.AsArray();
+
+			Assert.Equal(new[] { WeeksAgo(1), WeeksAgo(2) }, weeks.Select(w => w.Text("week")));
+			Assert.Equal(("cdn", "fastly.com"), (weeks[0]!["geo"].Text("precision"), weeks[0]!["geo"].Text("cdn_domain")));
+			Assert.Null(weeks[0]!["geo"]!["city"]);
+			Assert.Equal(("city", "Milan"), (weeks[1]!["geo"].Text("precision"), weeks[1]!["geo"].Text("city")));
+			Assert.Equal(3, weeks[1]!["users_total"]!.GetValue<long>());
+			Assert.Single((await _host.Client().Get($"/api/privapub/v1/instances/{host}/history?weeks=1")).Ok().Body!.AsArray());
+			Assert.Equal(HttpStatusCode.NotFound, (await _host.Client().Get($"/api/privapub/v1/instances/unknown{Guid.NewGuid():N}.example/history")).Status);
+		}
+
+		[Fact]
+		public async Task Servers_are_grouped_by_their_cdn_week_by_week()
+		{
+			var cdn = $"Edge{Guid.NewGuid():N}"[..20];
+			var key = cdn.ToLowerInvariant();
+			var stayed = await Instance(3, new InstanceGeo { Country = "FR", Cdn = cdn, CdnSource = "headers" }, "stayed");
+			var moved = await Instance(3, Milan(), "moved");
+			await Snapshot(moved, 3, cdn: cdn);
+			await Snapshot(moved, 2, cdn: cdn);
+			await Snapshot(stayed, 2, cdn: cdn);
+			await Snapshot(moved, 1, city: "Milan", latitude: 45.5, longitude: 9.2, country: "IT");
+			await Snapshot(stayed, 1, cdn: cdn);
+
+			var list = (await _host.Client().Get("/api/privapub/v1/cdns")).Ok().Body!.AsArray();
+			var group = list.Single(g => g.Text("key") == key);
+			Assert.Equal((cdn, 1), (group.Text("name"), group["servers"]!.GetValue<int>()));
+			var cloudflare = list.Single(g => g.Text("key") == "cloudflare.com");
+			Assert.Equal(new[] { "ranges", "headers", "asn" }, cloudflare["detected_by"]!.AsArray().Select(v => v!.GetValue<string>()));
+
+			var detail = (await _host.Client().Get($"/api/privapub/v1/cdns/{key}")).Ok().Body;
+			Assert.Equal(new[] { stayed }, detail["hosts"]!.AsArray().Select(h => h!.GetValue<string>()));
+			var weeks = detail["weeks"]!.AsArray();
+			Assert.Equal(new[] { WeeksAgo(1), WeeksAgo(2), WeeksAgo(3) }, weeks.Select(w => w.Text("week")));
+			Assert.Equal(new[] { 1, 2, 1 }, weeks.Select(w => w!["servers"]!.GetValue<int>()));
+			Assert.Equal(new[] { moved }, weeks[0]!["left"]!.AsArray().Select(h => h!.GetValue<string>()));
+			Assert.Equal(new[] { stayed }, weeks[1]!["joined"]!.AsArray().Select(h => h!.GetValue<string>()));
+			Assert.Equal(new[] { moved }, weeks[2]!["joined"]!.AsArray().Select(h => h!.GetValue<string>()));
+
+			Assert.Equal("Cloudflare", (await _host.Client().Get("/api/privapub/v1/cdns/cloudflare.com")).Ok().Body.Text("name"));
+			Assert.Equal(HttpStatusCode.NotFound, (await _host.Client().Get($"/api/privapub/v1/cdns/none{Guid.NewGuid():N}")).Status);
+		}
+
+		[Fact]
+		public async Task Junk_hosts_are_not_an_error()
+		{
+			Assert.Equal(HttpStatusCode.NotFound, (await _host.Client().Get($"/api/privapub/v1/instances/{new string('a', 300)}")).Status);
+			Assert.Empty((await _host.Client().Get($"/api/privapub/v1/instances?host[]=&host[]={new string('a', 300)}")).Ok().Body!.AsArray());
+		}
+	}
+
+	public sealed class SelfPlacedHost : PrivaPubHost
+	{
+		static readonly SemaphoreSlim Boot = new(1, 1);
+		static SelfPlacedHost _shared;
+
+		public static new async Task<SelfPlacedHost> Shared()
+		{
+			await PrivaPubHost.Shared();
+			await Boot.WaitAsync();
+			try
+			{
+				if (_shared == default)
+				{
+					var host = new SelfPlacedHost();
+					_ = host.Services;
+					_shared = host;
+				}
+				return _shared;
+			}
+			finally
+			{
+				Boot.Release();
+			}
+		}
+
+		protected override IEnumerable<KeyValuePair<string, string>> Settings() => base.Settings().Concat(new Dictionary<string, string>
+		{
+			["Statistics:Geo:Self:Latitude"] = "45.4642",
+			["Statistics:Geo:Self:Longitude"] = "9.19",
+			["Statistics:Geo:Self:City"] = "Milan",
+			["Statistics:Geo:Self:Country"] = "IT"
+		});
+	}
+}

PrivaPub.Tests/Http/MastodonAccountsTests.cs

@@ -127,7 +127,7 @@ namespace PrivaPub.Tests.Http
 		}
 
 		[Fact]
-		public async Task Lookup_finds_local_and_remote_accounts_but_never_a_circle_or_the_instance_actor()
+		public async Task Lookup_finds_local_and_remote_accounts_but_never_a_circle_or_the_servers_own_actors()
 		{
 			var alice = await _host.Mastodon("alice");
 			var (bob, bobId) = await Remote();
@@ -149,6 +149,7 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.Get($"/api/v1/accounts/lookup?acct={circleName}")).Status);
 			Assert.Equal(HttpStatusCode.NotFound, (await alice.Client.Get($"/api/v1/accounts/lookup?acct={circleName}")).Status);
 			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.Get("/api/v1/accounts/lookup?acct=privapub")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.Get("/api/v1/accounts/lookup?acct=privapub_reports")).Status);
 			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.Get($"/api/v1/accounts/lookup?acct=nobody{Guid.NewGuid():N}")).Status);
 			Assert.Equal(HttpStatusCode.NotFound, (await anonymous.Get("/api/v1/accounts/lookup?acct=a@b@c")).Status);
 
@@ -183,6 +184,33 @@ namespace PrivaPub.Tests.Http
 			Assert.Contains(alice.Id, (await alice.Client.Get($"/api/v1/accounts/search?q={alice.UserName}")).Ok().Ids);
 		}
 
+		// an account elsewhere: what it features, in its order, its public posts only
+		[Fact]
+		public async Task A_remote_accounts_pinned_statuses_are_what_it_features()
+		{
+			var alice = await _host.Mastodon("alice");
+			var (bob, bobId) = await Remote();
+			Post Held(string text, PostVisibility visibility) => new()
+			{
+				ObjectURI = $"{bob.Id}/statuses/{Guid.NewGuid():N}", ActorURI = bob.Id, AuthorAccountId = bobId, IsFederatedCopy = true,
+				Visibility = visibility, ContentHtml = $"<p>{text}</p>", CreationDate = DateTime.UtcNow, UpdateDate = DateTime.UtcNow
+			};
+			var first = Held("first pin", PostVisibility.Public);
+			var second = Held("second pin", PostVisibility.Unlisted);
+			var hidden = Held("for followers", PostVisibility.FollowersOnly);
+			await DB.Default.SaveAsync(new[] { first, second, hidden }, Token);
+			await DB.Default.SaveAsync(new[]
+			{
+				new RemoteFeatured { ActorURI = bob.Id, ObjectURI = second.ObjectURI, PostId = second.ID, Position = 1 },
+				new RemoteFeatured { ActorURI = bob.Id, ObjectURI = hidden.ObjectURI, PostId = hidden.ID, Position = 2 },
+				new RemoteFeatured { ActorURI = bob.Id, ObjectURI = first.ObjectURI, PostId = first.ID, Position = 0 }
+			}, Token);
+
+			var pinned = (await alice.Client.Get($"/api/v1/accounts/{bobId}/statuses?pinned=true")).Ok();
+
+			Assert.Equal(new[] { first.ID, second.ID }, pinned.Ids);
+		}
+
 		[Fact]
 		public async Task Account_statuses_filter_pins_replies_reblogs_media_and_tags_and_page_both_ways()
 		{
@@ -493,6 +521,23 @@ namespace PrivaPub.Tests.Http
 			Assert.All(answer.Array, r => Assert.False(r.Flag("following") || r.Flag("blocking") || r.Flag("muting") || r.Flag("followed_by")));
 		}
 
+		[Fact]
+		public async Task Following_again_sends_an_unanswered_request_once_more_and_no_more_than_hourly()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var (bob, bobId) = await Remote();
+			Assert.True((await alice.Client.Post($"/api/v1/accounts/{bobId}/follow")).Ok().Body.Flag("requested"));
+			var first = Assert.Single(await bob.Delivered(since), d => d.Type() == "Follow");
+
+			Assert.True((await alice.Client.Post($"/api/v1/accounts/{bobId}/follow")).Ok().Body.Flag("requested"));
+			(await alice.Client.Post($"/api/v1/accounts/{bobId}/follow")).Ok();
+
+			var follows = (await bob.Delivered(since)).Where(d => d.Type() == "Follow").ToList();
+			Assert.Equal(2, follows.Count);
+			Assert.All(follows, f => Assert.Equal(first.Text("id"), f.Text("id")));
+		}
+
 		[Fact]
 		public async Task A_remote_authors_followers_only_posts_show_only_to_the_personas_that_follow_them()
 		{
@@ -619,7 +664,6 @@ namespace PrivaPub.Tests.Http
 			var alice = await _host.Mastodon("alice");
 
 			Assert.Empty((await _host.Client().Get($"/api/v1/accounts/{alice.Id}/featured_tags")).Ok().Array);
-			Assert.Empty((await alice.Client.Get($"/api/v1/accounts/{alice.Id}/lists")).Ok().Array);
 			var familiar = (await alice.Client.Get($"/api/v1/accounts/familiar_followers?id[]={alice.Id}")).Ok();
 			Assert.Equal(alice.Id, Assert.Single(familiar.Array).Text("id"));
 			Assert.Empty(familiar.Array[0]!["accounts"]!.AsArray());

PrivaPub.Tests/Http/MastodonFeedTests.cs

@@ -0,0 +1,140 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Lemmy 1.0's multi-communities and PieFed's feeds are `Feed` actors whose `following` is their communities
+	[Trait("Category", "Integration")]
+	public sealed class MastodonFeedTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		Peer _peer;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task A_feed_shows_as_an_account_whose_following_is_its_communities()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var reader = await _host.Mastodon("feeder");
+			var cats = new RemoteActor(_peer, "cats", type: "Group");
+			var dogs = new RemoteActor(_peer, "dogs", type: "Group");
+			var name = $"feed{Guid.NewGuid():N}"[..12];
+			var feed = $"{_peer.A}/m/{name}";
+			// as Lemmy serves one: the instance's inbox and key, its text in `description`
+			_peer.Serve($"/m/{name}", new JsonObject
+			{
+				["@context"] = new JsonArray("https://join-lemmy.org/context.json", "https://www.w3.org/ns/activitystreams"),
+				["type"] = "Feed", ["id"] = feed, ["inbox"] = $"{_peer.A}/inbox",
+				["publicKey"] = new JsonObject { ["id"] = $"{_peer.A}/#main-key", ["owner"] = $"{_peer.A}/", ["publicKeyPem"] = "-----BEGIN PUBLIC KEY-----\n-----END PUBLIC KEY-----\n" },
+				["following"] = $"{feed}/following", ["preferredUsername"] = name, ["name"] = "Pets", ["description"] = "every pet",
+				["attributedTo"] = $"{_peer.A}/users/owner"
+			}.ToJsonString());
+			_peer.Serve($"/m/{name}/following", new JsonObject
+			{
+				["type"] = "Collection", ["id"] = $"{feed}/following", ["totalItems"] = 2, ["items"] = new JsonArray(cats.Id, dogs.Id)
+			}.ToJsonString());
+
+			var account = await _host.Get<IRemoteActorService>().GetActor(feed, refresh: true, token);
+			Assert.NotNull(account);
+			await _host.Run(j => j.Kind == JobKind.CountAccount && j.Payload == feed, token);
+
+			var shown = (await reader.Client.Get($"/api/v1/accounts/{account.ID}")).Ok().Body;
+			Assert.Equal(("Pets", 2), (shown.Text("display_name"), shown.Number("following_count")));
+			Assert.Contains("every pet", shown.Text("note"));
+			var communities = (await reader.Client.Get($"/api/v1/accounts/{account.ID}/following")).Ok().Array;
+			Assert.Equal(new[] { cats.Id, dogs.Id }, communities.Select(c => c.Text("uri")));
+			Assert.All(communities, c => Assert.True(c!["group"]!.GetValue<bool>()));
+		}
+
+		// owner decision 2026-10-07: a feed is read through the server, whose reader follows its communities; the persona
+		// follows nothing, and reads the feed in a timeline of its own
+		[Fact]
+		public async Task A_feed_is_followed_by_the_servers_reader_and_read_in_its_own_timeline()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var persona = await _host.Mastodon("feedreader");
+			var cats = new RemoteActor(_peer, "cats", type: "Group");
+			var dogs = new RemoteActor(_peer, "dogs", type: "Group");
+			var poster = new RemoteActor(_peer, "poster");
+			var name = $"feed{Guid.NewGuid():N}"[..12];
+			var feed = $"{_peer.A}/m/{name}";
+			_peer.Serve($"/m/{name}", new JsonObject
+			{
+				["type"] = "Feed", ["id"] = feed, ["inbox"] = $"{_peer.A}/inbox", ["following"] = $"{feed}/following", ["preferredUsername"] = name, ["name"] = "Pets"
+			}.ToJsonString());
+			_peer.Serve($"/m/{name}/following", new JsonObject
+			{
+				["type"] = "Collection", ["id"] = $"{feed}/following", ["totalItems"] = 2, ["items"] = new JsonArray(cats.Id, dogs.Id)
+			}.ToJsonString());
+			var account = await _host.Get<IRemoteActorService>().GetActor(feed, refresh: true, token);
+			await _host.Run(j => j.Kind == JobKind.CountAccount && j.Payload == feed, token);
+
+			var followed = (await persona.Client.Post($"/api/v1/accounts/{account.ID}/follow")).Ok().Body;
+			Assert.True(followed.Flag("following"));
+			Assert.Equal(new[] { account.ID }, (await persona.Client.Get("/api/v1/feeds")).Ok().Ids);
+			await _host.Run(j => j.Kind == JobKind.SyncFeeds, token);
+
+			var readerActor = await _host.Get<ILocalActorService>().GetReaderActor(token);
+			var follows = await DB.Default.Find<Following>().Match(f => f.AvatarId == readerActor.Id).ExecuteAsync(token);
+			Assert.Equal(new[] { cats.Id, dogs.Id }.Order(), follows.Select(f => f.TargetActorURI).Order());
+			Assert.All(follows, f => Assert.Equal(LocalActorKind.Reader, f.FollowerKind));
+			Assert.False(await DB.Default.Find<Following>().Match(f => f.AvatarId == persona.Id).ExecuteAnyAsync(token));
+			var asked = Assert.Single(await cats.Delivered(since), d => d.Type() == "Follow");
+			Assert.Equal(readerActor.Uri, asked.Text("actor"));
+			var document = (await _host.Client().Fetch(new Uri(readerActor.Uri).AbsolutePath)).Json;
+			Assert.Equal(("Service", LocalActorService.ReaderUserName), (document.Text("type"), document.Text("preferredUsername")));
+
+			await _host.Deliver(cats, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{cats.Id}/accepts/{Guid.NewGuid():N}", ["type"] = "Accept", ["actor"] = cats.Id, ["object"] = asked.Text("id")
+			});
+			var create = poster.Create("<p>a thread among cats</p>", new[] { "https://www.w3.org/ns/activitystreams#Public", cats.Id }, shape: note =>
+			{
+				note["type"] = "Page";
+				note["name"] = "Cats";
+				note["audience"] = cats.Id;
+			});
+			_peer.Serve(new Uri(create["object"]!.Text("id")).AbsolutePath, create["object"]!.ToJsonString());
+			await _host.Deliver(cats, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{cats.Id}/announces/{Guid.NewGuid():N}", ["type"] = "Announce", ["actor"] = cats.Id, ["object"] = create,
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public")
+			});
+			var thread = await DB.Default.Find<Post>().Match(p => p.ObjectURI == create["object"]!.Text("id")).ExecuteSingleAsync(token);
+
+			Assert.Equal(new[] { thread.ID }, (await persona.Client.Get($"/api/v1/timelines/feed/{account.ID}")).Ok().Ids);
+			Assert.DoesNotContain(thread.ID, (await persona.Client.Get("/api/v1/timelines/home")).Ok().Ids);
+			Assert.False(await DB.Default.Find<TimelineEntry>().Match(e => e.PostId == thread.ID).ExecuteAnyAsync(token));
+			var stranger = await _host.Mastodon("notreading");
+			Assert.Equal(HttpStatusCode.NotFound, (await stranger.Client.Get($"/api/v1/timelines/feed/{account.ID}")).Status);
+
+			Assert.False((await persona.Client.Post($"/api/v1/accounts/{account.ID}/unfollow")).Ok().Body.Flag("following"));
+			await _host.Run(j => j.Kind == JobKind.SyncFeeds, token);
+			Assert.False(await DB.Default.Find<Following>().Match(f => f.AvatarId == readerActor.Id).ExecuteAnyAsync(token));
+			Assert.Contains(await cats.Delivered(since), d => d.Type() == "Undo" && d["object"].Text("type") == "Follow");
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonFiltersTests.cs

@@ -0,0 +1,169 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Mastodon's filters: a persona's v2 filters with keywords and statuses, the v1 API over their keywords, and the
+	// `filtered` each status carries for the filters it matches
+	[Trait("Category", "Integration")]
+	public sealed class MastodonFiltersTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static Task<ApiAnswer> Create(Mastodon owner, string title, string action, params (string Keyword, bool WholeWord)[] keywords) =>
+			owner.Client.Json(HttpMethod.Post, "/api/v2/filters", new JsonObject
+			{
+				["title"] = title,
+				["context"] = new JsonArray("home", "public", "thread"),
+				["filter_action"] = action,
+				["keywords_attributes"] = new JsonArray(keywords.Select(k => (JsonNode)new JsonObject { ["keyword"] = k.Keyword, ["whole_word"] = k.WholeWord }).ToArray())
+			});
+
+		[Fact]
+		public async Task A_filter_is_made_changed_and_deleted_by_its_owner_only()
+		{
+			var alice = await _host.Mastodon("alice");
+			var mallory = await _host.Mastodon("mallory");
+
+			var made = (await Create(alice, "Spoilers", "hide", ("spoiler", true), ("leak", false))).Ok().Object;
+			var id = made.Text("id");
+			Assert.Equal("hide", made.Text("filter_action"));
+			Assert.Equal(new[] { "home", "public", "thread" }, made["context"]!.AsArray().Select(c => c!.GetValue<string>()));
+			var keywords = made["keywords"]!.AsArray();
+			Assert.Equal(new[] { "spoiler", "leak" }, keywords.Select(k => k.Text("keyword")));
+			Assert.Equal(new[] { true, false }, keywords.Select(k => k!.Flag("whole_word")));
+			Assert.Null(made["expires_at"]);
+
+			var changed = (await alice.Client.Json(HttpMethod.Put, $"/api/v2/filters/{id}", new JsonObject
+			{
+				["title"] = "Leaks",
+				["filter_action"] = "warn",
+				["expires_in"] = 3600,
+				["keywords_attributes"] = new JsonArray(
+					new JsonObject { ["id"] = keywords[0].Text("id"), ["_destroy"] = true },
+					new JsonObject { ["keyword"] = "ending" })
+			})).Ok().Object;
+			Assert.Equal("Leaks", changed.Text("title"));
+			Assert.Equal("warn", changed.Text("filter_action"));
+			Assert.NotNull(changed.Text("expires_at"));
+			Assert.Equal(new[] { "leak", "ending" }, changed["keywords"]!.AsArray().Select(k => k.Text("keyword")));
+
+			var added = (await alice.Client.Post($"/api/v2/filters/{id}/keywords", ("keyword", "finale"), ("whole_word", "false"))).Ok().Object;
+			Assert.False(added.Flag("whole_word"));
+			var keywordId = added.Text("id");
+			Assert.Equal("finale", (await alice.Client.Get($"/api/v2/filters/keywords/{keywordId}")).Ok().Object.Text("keyword"));
+			Assert.Equal("last scene", (await alice.Client.Put($"/api/v2/filters/keywords/{keywordId}", ("keyword", "last scene"))).Ok().Object.Text("keyword"));
+			(await alice.Client.Delete($"/api/v2/filters/keywords/{keywordId}")).Ok();
+			Assert.Equal(2, (await alice.Client.Get($"/api/v2/filters/{id}/keywords")).Ok().Array.Count);
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Create(alice, " ", "warn", ("x", true))).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Create(alice, "x", "explode", ("x", true))).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v2/filters", ("title", "x"), ("context[]", "everywhere"))).Status);
+			Assert.Empty((await mallory.Client.Get("/api/v2/filters")).Ok().Array);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Get($"/api/v2/filters/{id}")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Delete($"/api/v2/filters/keywords/{changed["keywords"]![0].Text("id")}")).Status);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _host.Client().Get("/api/v2/filters")).Status);
+
+			(await alice.Client.Delete($"/api/v2/filters/{id}")).Ok();
+			Assert.Empty((await alice.Client.Get("/api/v2/filters")).Ok().Array);
+		}
+
+		[Fact]
+		public async Task Statuses_carry_the_filters_they_match_by_word_and_by_id()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			(await bob.Client.Post($"/api/v1/accounts/{alice.Id}/follow")).Ok();
+			var filterId = (await Create(alice, "Spoilers", "warn", ("spoiler", true), ("#tv", true))).Ok().Object.Text("id");
+			var other = (await Create(bob, "Not mine", "hide", ("spoiler", false))).Ok().Object.Text("id");
+			var whole = (await alice.Status("a big SPOILER ahead")).Text("id");
+			var partial = (await alice.Status("spoilers galore")).Text("id");
+			var tagged = (await alice.Status("watching #TV tonight")).Text("id");
+			var plain = (await alice.Status("nothing to see")).Text("id");
+			var warned = (await alice.Status("calm text", ("spoiler_text", "spoiler inside"))).Text("id");
+			var byId = (await alice.Client.Post($"/api/v2/filters/{filterId}/statuses", ("status_id", plain))).Ok().Object;
+			Assert.Equal(plain, byId.Text("status_id"));
+			var boost = (await bob.Client.Post($"/api/v1/statuses/{whole}/reblog")).Ok().Object.Text("id");
+
+			var home = (await alice.Client.Get("/api/v1/timelines/home?limit=40")).Ok().Array.ToDictionary(s => s.Text("id"), s => s!["filtered"]!.AsArray());
+			var match = Assert.Single(home[whole]);
+			Assert.Equal(filterId, match!["filter"].Text("id"));
+			Assert.Equal("warn", match["filter"].Text("filter_action"));
+			Assert.Equal(new[] { "spoiler" }, match["keyword_matches"]!.AsArray().Select(k => k!.GetValue<string>()));
+			Assert.Empty(home[partial]);
+			Assert.Equal(new[] { "#tv" }, Assert.Single(home[tagged])!["keyword_matches"]!.AsArray().Select(k => k!.GetValue<string>()));
+			Assert.Equal(new[] { byId.Text("id") }, Assert.Single(home[plain])!["status_matches"]!.AsArray().Select(k => k!.GetValue<string>()));
+			Assert.Single(home[warned]);
+			Assert.Single((await alice.Client.Get($"/api/v1/statuses/{boost}")).Ok().Body["filtered"]!.AsArray());
+
+			var asBob = (await bob.Client.Get($"/api/v1/statuses/{partial}")).Ok().Body["filtered"]!.AsArray();
+			Assert.Equal(other, Assert.Single(asBob)!["filter"].Text("id"));
+			Assert.Empty((await _host.Client().Get($"/api/v1/statuses/{whole}")).Ok().Body["filtered"]!.AsArray());
+
+			// an expired filter matches nothing
+			await DB.Default.Update<PersonaFilter>().MatchID(filterId).Modify(f => f.ExpiresAt, DateTime.UtcNow.AddMinutes(-1)).ExecuteAsync(Token);
+			Assert.Empty((await alice.Client.Get($"/api/v1/statuses/{whole}")).Ok().Body["filtered"]!.AsArray());
+		}
+
+		[Fact]
+		public async Task Keywords_come_as_form_fields_listed_or_numbered()
+		{
+			var alice = await _host.Mastodon("alice");
+
+			var listed = (await alice.Client.Post("/api/v2/filters", ("title", "Listed"), ("context[]", "home"),
+				("keywords_attributes[][keyword]", "one"), ("keywords_attributes[][whole_word]", "false"),
+				("keywords_attributes[][keyword]", "two"), ("keywords_attributes[][whole_word]", "true"))).Ok().Object;
+			Assert.Equal(new[] { ("one", false), ("two", true) },
+				listed["keywords"]!.AsArray().Select(k => (k.Text("keyword"), k!.Flag("whole_word"))));
+
+			var numbered = (await alice.Client.Post("/api/v2/filters", ("title", "Numbered"), ("context[]", "public"),
+				("keywords_attributes[1][keyword]", "second"), ("keywords_attributes[0][keyword]", "first"),
+				("keywords_attributes[0][whole_word]", "false"))).Ok().Object;
+			Assert.Equal(new[] { ("first", false), ("second", true) },
+				numbered["keywords"]!.AsArray().Select(k => (k.Text("keyword"), k!.Flag("whole_word"))));
+		}
+
+		[Fact]
+		public async Task A_v1_filter_is_one_keyword_of_a_v2_filter()
+		{
+			var alice = await _host.Mastodon("alice");
+
+			var made = (await alice.Client.Post("/api/v1/filters", ("phrase", "election"), ("context[]", "home"), ("context[]", "notifications"),
+				("irreversible", "true"), ("whole_word", "false"))).Ok().Object;
+			var id = made.Text("id");
+			Assert.Equal("election", made.Text("phrase"));
+			Assert.True(made.Flag("irreversible"));
+			Assert.False(made.Flag("whole_word"));
+			var v2 = Assert.Single((await alice.Client.Get("/api/v2/filters")).Ok().Array)!;
+			Assert.Equal("election", v2.Text("title"));
+			Assert.Equal("hide", v2.Text("filter_action"));
+			Assert.Equal(id, Assert.Single(v2["keywords"]!.AsArray()).Text("id"));
+
+			var changed = (await alice.Client.Put($"/api/v1/filters/{id}", ("phrase", "elections"), ("irreversible", "false"))).Ok().Object;
+			Assert.Equal("elections", changed.Text("phrase"));
+			Assert.False(changed.Flag("irreversible"));
+			Assert.Equal(new[] { id }, (await alice.Client.Get("/api/v1/filters")).Ok().Ids);
+			Assert.Equal("elections", (await alice.Client.Get($"/api/v1/filters/{id}")).Ok().Object.Text("phrase"));
+
+			(await alice.Client.Delete($"/api/v1/filters/{id}")).Ok();
+			Assert.Empty((await alice.Client.Get("/api/v2/filters")).Ok().Array);
+			Assert.Equal(HttpStatusCode.NotFound, (await alice.Client.Get($"/api/v1/filters/{id}")).Status);
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonInstanceTests.cs

@@ -41,7 +41,12 @@ namespace PrivaPub.Tests.Http
 			var v2 = (await anonymous.Get("/api/v2/instance")).Ok();
 			Assert.Equal(InstanceController.Version, v2.Body.Text("version"));
 			Assert.Equal(PrivaPubHost.Host, v2.Body.Text("domain"));
-			Assert.Equal($"wss://{PrivaPubHost.Host}", v2.Body["configuration"]!["urls"].Text("streaming"));
+			Assert.Equal($"wss://{PrivaPubHost.Host}", v2.Body["configuration"]!["urls"]!.Text("streaming"));
+			Assert.Equal($"wss://{PrivaPubHost.Host}", v1.Body["urls"]!.Text("streaming_api"));
+			Assert.Equal(PrivaPub.Api.Mastodon.Controllers.StatusesController.MaxPins, v2.Body["configuration"]!["accounts"].Number("max_pinned_statuses"));
+			Assert.Contains("image/avif", v2.Body["configuration"]!["media_attachments"]!["supported_mime_types"]!.AsArray().Select(t => t!.GetValue<string>()));
+			// what the bundled libvips can't decode is not offered
+			Assert.DoesNotContain("image/heic", v2.Body["configuration"]!["media_attachments"]!["supported_mime_types"]!.AsArray().Select(t => t!.GetValue<string>()));
 			Assert.True(v2.Body["registrations"].Flag("enabled"));
 			Assert.True((await anonymous.Get("/nodeinfo/2.1")).Ok().Body.Flag("openRegistrations"));
 			Assert.False(v2.Body["configuration"]!["translation"].Flag("enabled"));
@@ -67,25 +72,16 @@ namespace PrivaPub.Tests.Http
 		[Theory]
 		[InlineData("/api/v1/custom_emojis")]
 		[InlineData("/api/v1/announcements")]
-		[InlineData("/api/v1/trends")]
-		[InlineData("/api/v1/trends/tags")]
-		[InlineData("/api/v1/trends/statuses")]
-		[InlineData("/api/v1/trends/links")]
 		public async Task Public_stub_routes_answer_empty_lists_to_anyone(string path)
 		{
 			Assert.Empty((await _host.Client().Get(path)).Ok().Array);
 		}
 
 		[Theory]
-		[InlineData("/api/v1/filters")]
-		[InlineData("/api/v2/filters")]
-		[InlineData("/api/v1/lists")]
 		[InlineData("/api/v1/suggestions")]
 		[InlineData("/api/v2/suggestions")]
-		[InlineData("/api/v1/followed_tags")]
 		[InlineData("/api/v1/endorsements")]
 		[InlineData("/api/v1/featured_tags")]
-		[InlineData("/api/v1/scheduled_statuses")]
 		public async Task Signed_in_stub_routes_answer_empty_lists(string path)
 		{
 			var reader = await _host.Mastodon("reader");

PrivaPub.Tests/Http/MastodonListsTests.cs

@@ -0,0 +1,179 @@
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Http
+{
+	// Mastodon's lists: a persona's own groups of accounts it follows, read as timelines, never federated
+	[Trait("Category", "Integration")]
+	public sealed class MastodonListsTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static async Task Follow(Mastodon follower, Mastodon target) =>
+			(await follower.Client.Post($"/api/v1/accounts/{target.Id}/follow")).Ok();
+
+		static async Task<string> List(Mastodon owner, string title, params (string Key, string Value)[] more) =>
+			(await owner.Client.Post("/api/v1/lists", more.Prepend(("title", title)).ToArray())).Ok().Object.Text("id");
+
+		[Fact]
+		public async Task A_list_is_created_renamed_and_deleted_by_its_owner_only()
+		{
+			var alice = await _host.Mastodon("alice");
+			var mallory = await _host.Mastodon("mallory");
+
+			var created = (await alice.Client.Post("/api/v1/lists", ("title", "Friends"), ("replies_policy", "followed"), ("exclusive", "true"))).Ok().Object;
+			var id = created.Text("id");
+			Assert.Equal("Friends", created.Text("title"));
+			Assert.Equal("followed", created.Text("replies_policy"));
+			Assert.True(created.Flag("exclusive"));
+			var other = await List(alice, "Art");
+
+			Assert.Equal(new[] { other, id }, (await alice.Client.Get("/api/v1/lists")).Ok().Ids);
+			var renamed = (await alice.Client.Put($"/api/v1/lists/{id}", ("title", "Close friends"), ("exclusive", "false"))).Ok().Object;
+			Assert.Equal("Close friends", renamed.Text("title"));
+			Assert.Equal("followed", renamed.Text("replies_policy"));
+			Assert.False(renamed.Flag("exclusive"));
+			Assert.Equal("Close friends", (await alice.Client.Get($"/api/v1/lists/{id}")).Ok().Object.Text("title"));
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/lists", ("title", " "))).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/lists", ("title", "x"), ("replies_policy", "everyone"))).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Put($"/api/v1/lists/{id}", ("title", ""))).Status);
+			Assert.Empty((await mallory.Client.Get("/api/v1/lists")).Ok().Array);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Get($"/api/v1/lists/{id}")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Put($"/api/v1/lists/{id}", ("title", "mine"))).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Delete($"/api/v1/lists/{id}")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Get($"/api/v1/timelines/list/{id}")).Status);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _host.Client().Get("/api/v1/lists")).Status);
+
+			(await alice.Client.Delete($"/api/v1/lists/{id}")).Ok();
+			Assert.Equal(new[] { other }, (await alice.Client.Get("/api/v1/lists")).Ok().Ids);
+			Assert.Equal(HttpStatusCode.NotFound, (await alice.Client.Get($"/api/v1/lists/{id}")).Status);
+		}
+
+		[Fact]
+		public async Task Only_followed_accounts_join_a_list_and_its_timeline_shows_their_posts()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var carol = await _host.Mastodon("carol");
+			var dave = await _host.Mastodon("dave");
+			await Follow(alice, bob);
+			await Follow(alice, dave);
+			var list = await List(alice, "Bob");
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", carol.Id))).Status);
+			(await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+			(await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+			Assert.Equal(new[] { bob.Id }, (await alice.Client.Get($"/api/v1/lists/{list}/accounts")).Ok().Ids);
+			Assert.Equal(new[] { list }, (await alice.Client.Get($"/api/v1/accounts/{bob.Id}/lists")).Ok().Ids);
+			Assert.Empty((await alice.Client.Get($"/api/v1/accounts/{dave.Id}/lists")).Ok().Array);
+
+			var fromBob = (await bob.Status("from bob")).Text("id");
+			await dave.Status("from dave");
+			await carol.Status("from carol");
+			Assert.Equal(new[] { fromBob }, (await alice.Client.Get($"/api/v1/timelines/list/{list}")).Ok().Ids);
+
+			(await alice.Client.Delete($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+			Assert.Empty((await alice.Client.Get($"/api/v1/lists/{list}/accounts")).Ok().Array);
+			Assert.Empty((await alice.Client.Get($"/api/v1/timelines/list/{list}")).Ok().Array);
+		}
+
+		[Theory]
+		[InlineData("list", true, false, false)]
+		[InlineData("followed", true, true, false)]
+		[InlineData("none", true, false, false)]
+		public async Task A_lists_replies_follow_its_policy(string policy, bool toSelf, bool toFollowed, bool toStranger)
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var dave = await _host.Mastodon("dave");
+			var carol = await _host.Mastodon("carol");
+			await Follow(alice, bob);
+			await Follow(alice, dave);
+			var list = await List(alice, "Bob", ("replies_policy", policy));
+			(await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+			var root = (await bob.Status("a thread")).Text("id");
+			var mine = (await alice.Status("asking bob")).Text("id");
+			var ofDave = (await dave.Status("dave's")).Text("id");
+			var ofCarol = (await carol.Status("carol's")).Text("id");
+
+			var self = (await bob.Status("and more", ("in_reply_to_id", root))).Text("id");
+			var toAlice = (await bob.Status($"@{alice.UserName} answered", ("in_reply_to_id", mine))).Text("id");
+			var toDave = (await bob.Status($"@{dave.UserName} agreed", ("in_reply_to_id", ofDave))).Text("id");
+			var toCarol = (await bob.Status($"@{carol.UserName} hm", ("in_reply_to_id", ofCarol))).Text("id");
+
+			var shown = (await alice.Client.Get($"/api/v1/timelines/list/{list}")).Ok().Ids.ToList();
+			Assert.Contains(root, shown);
+			Assert.Equal(toSelf, shown.Contains(self));
+			Assert.Contains(toAlice, shown);
+			Assert.Equal(toFollowed, shown.Contains(toDave));
+			Assert.Equal(toStranger, shown.Contains(toCarol));
+		}
+
+		[Fact]
+		public async Task An_exclusive_lists_members_are_read_there_and_not_at_home()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var dave = await _host.Mastodon("dave");
+			await Follow(alice, bob);
+			await Follow(alice, dave);
+			var list = await List(alice, "Apart", ("exclusive", "true"));
+			(await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+			var fromBob = (await bob.Status("from bob")).Text("id");
+			var fromDave = (await dave.Status("from dave")).Text("id");
+
+			var home = (await alice.Client.Get("/api/v1/timelines/home")).Ok().Ids.ToList();
+			Assert.Contains(fromDave, home);
+			Assert.DoesNotContain(fromBob, home);
+			Assert.Equal(new[] { fromBob }, (await alice.Client.Get($"/api/v1/timelines/list/{list}")).Ok().Ids);
+
+			(await alice.Client.Put($"/api/v1/lists/{list}", ("exclusive", "false"))).Ok();
+			Assert.Contains(fromBob, (await alice.Client.Get("/api/v1/timelines/home")).Ok().Ids);
+		}
+
+		[Fact]
+		public async Task Account_search_with_following_finds_only_followed_accounts()
+		{
+			var alice = await _host.Mastodon("alice");
+			var prefix = $"ls{Guid.NewGuid():N}"[..10];
+			var followed = await _host.Mastodon(prefix + "a");
+			var stranger = await _host.Mastodon(prefix + "b");
+			await Follow(alice, followed);
+
+			var found = (await alice.Client.Get($"/api/v1/accounts/search?q={prefix}&following=true")).Ok().Ids.ToList();
+			Assert.Equal(new[] { followed.Id }, found);
+			Assert.Contains(stranger.Id, (await alice.Client.Get($"/api/v1/accounts/search?q={prefix}")).Ok().Ids);
+			Assert.Empty((await stranger.Client.Get($"/api/v1/accounts/search?q={prefix}&following=true")).Ok().Array);
+		}
+
+		[Fact]
+		public async Task An_unfollowed_account_leaves_the_personas_lists_and_does_not_come_back_with_a_new_follow()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			await Follow(alice, bob);
+			var list = await List(alice, "Bob", ("exclusive", "true"));
+			(await alice.Client.Post($"/api/v1/lists/{list}/accounts", ("account_ids[]", bob.Id))).Ok();
+
+			(await alice.Client.Post($"/api/v1/accounts/{bob.Id}/unfollow")).Ok();
+			Assert.Empty((await alice.Client.Get($"/api/v1/lists/{list}/accounts")).Ok().Array);
+			Assert.Empty((await alice.Client.Get($"/api/v1/accounts/{bob.Id}/lists")).Ok().Array);
+
+			await Follow(alice, bob);
+			var fromBob = (await bob.Status("back again")).Text("id");
+			Assert.Contains(fromBob, (await alice.Client.Get("/api/v1/timelines/home")).Ok().Ids);
+			Assert.Empty((await alice.Client.Get($"/api/v1/lists/{list}/accounts")).Ok().Array);
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonMediaTests.cs

@@ -1,3 +1,4 @@
+using PrivaPub.Models.Jobs;
 using PrivaPub.Domain.Media;
 using PrivaPub.Tests.Support;
 using PrivaPub.Tests.Support.Host;
@@ -31,6 +32,14 @@ namespace PrivaPub.Tests.Http
 
 		static CancellationToken Token => TestContext.Current.CancellationToken;
 
+		// what GET /api/v1/media/:id answers once the job processing an upload sent to v2 has run
+		async Task<ApiAnswer> Processed(Mastodon account, ApiAnswer accepted)
+		{
+			var id = accepted.Body.Text("id");
+			await _host.Run(j => j.Kind == JobKind.ProcessMedia && j.Payload == id, Token);
+			return await account.Client.Get($"/api/v1/media/{id}");
+		}
+
 		static Task<ApiAnswer> Upload(Mastodon account, string path, byte[] bytes, string contentType, string fileName, params (string Key, string Value)[] fields)
 		{
 			var form = MastodonHelpers.Multipart(("file", bytes, contentType, fileName));
@@ -136,6 +145,25 @@ namespace PrivaPub.Tests.Http
 			Assert.Null((await alice.Client.Put($"/api/v1/media/{id}", ("description", ""))).Ok().Body.Text("description"));
 		}
 
+		// a focal point is two finite numbers: NaN or Infinity is ignored, never stored (it broke every timeline holding the post)
+		[Fact]
+		public async Task A_focal_point_that_is_not_a_number_is_ignored()
+		{
+			var alice = await _host.Mastodon("alice");
+			var uploaded = (await Upload(alice, "/api/v2/media", MastodonHelpers.JpegWithMetadata(32, 32), "image/jpeg", "a.jpg", ("focus", "NaN,NaN"))).Ok();
+			Assert.Null(uploaded.Body["meta"]?["focus"]);
+			var id = uploaded.Body.Text("id");
+
+			(await alice.Client.Put($"/api/v1/media/{id}", ("focus", "0.5,0.25"))).Ok();
+			foreach (var unsound in new[] { "NaN,0", "Infinity,1", "0,-Infinity" })
+			{
+				var focus = (await alice.Client.Put($"/api/v1/media/{id}", ("focus", unsound))).Ok().Body["meta"]!["focus"]!;
+				Assert.Equal((0.5, 0.25), (focus["x"]!.GetValue<double>(), focus["y"]!.GetValue<double>()));
+			}
+			var status = (await alice.Client.Post("/api/v1/statuses", ("status", "focused"), ("media_ids[]", id))).Ok();
+			Assert.Equal(0.5, status.Body["media_attachments"]![0]!["meta"]!["focus"]!["x"]!.GetValue<double>());
+		}
+
 		[Fact]
 		public async Task Unsupported_unreadable_and_missing_files_are_refused_with_422()
 		{
@@ -145,12 +173,50 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(HttpStatusCode.UnprocessableEntity, text.Status);
 			Assert.Contains("not supported", text.Body.Text("error"));
 			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Upload(alice, "/api/v2/media", Encoding.UTF8.GetBytes("not a jpeg"), "image/jpeg", "a.jpg")).Status);
-			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Upload(alice, "/api/v2/media", Encoding.UTF8.GetBytes("not a video"), "video/mp4", "a.mp4")).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Upload(alice, "/api/v1/media", Encoding.UTF8.GetBytes("not a video"), "video/mp4", "a.mp4")).Status);
+			// sent to v2, it is taken, then refused once processed
+			var later = await Upload(alice, "/api/v2/media", Encoding.UTF8.GetBytes("not a video"), "video/mp4", "a.mp4");
+			Assert.Equal(HttpStatusCode.Accepted, later.Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Processed(alice, later)).Status);
 			var empty = new MultipartFormDataContent { { new StringContent("no file"), "description" } };
 			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media") { Content = empty })).Status);
 			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/media")).Status);
 		}
 
+		// refused before anything is decoded: an SVG claiming to be a PNG, and an image that would decode to too many pixels
+		[Fact]
+		public async Task An_image_that_is_not_one_or_too_large_is_refused_before_decoding()
+		{
+			var alice = await _host.Mastodon("alice");
+			var svg = "<svg xmlns='http://www.w3.org/2000/svg' width='30000' height='30000'><rect width='1' height='1'/></svg>"u8.ToArray();
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await Upload(alice, "/api/v2/media", svg, "image/png", "a.png")).Status);
+
+			using var huge = NetVips.Image.Black(8000, 6000);
+			var tooLarge = await Upload(alice, "/api/v2/media", huge.WriteToBuffer(".png"), "image/png", "huge.png");
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, tooLarge.Status);
+			Assert.Contains("too large", tooLarge.Body.Text("error"));
+		}
+
+		// an animated GIF becomes what Mastodon makes of one, a looping mp4 typed gifv; a still GIF stays an image
+		[Fact]
+		public async Task An_animated_gif_becomes_a_gifv_and_a_still_one_an_image()
+		{
+			var alice = await _host.Mastodon("alice");
+			using var frame = (NetVips.Image.Black(64, 48, bands: 3) + 60).Cast(NetVips.Enums.BandFormat.Uchar);
+			using var frames = NetVips.Image.Arrayjoin(new[] { frame, frame + 80, frame + 160 }, across: 1).Cast(NetVips.Enums.BandFormat.Uchar);
+			using var animated = frames.Mutate(m => m.Set(NetVips.GValue.GIntType, "page-height", 48));
+
+			var gifv = (await Upload(alice, "/api/v2/media", animated.WriteToBuffer(".gif"), "image/gif", "dance.gif")).Ok();
+			Assert.Equal("gifv", gifv.Body.Text("type"));
+			Assert.EndsWith(".mp4", gifv.Body.Text("url"));
+			Assert.Equal(64, gifv.Body["meta"]!["original"]!["width"]!.GetValue<int>());
+			var status = (await alice.Client.Post("/api/v1/statuses", ("status", "dancing"), ("media_ids[]", gifv.Body.Text("id")))).Ok();
+			Assert.Equal("gifv", status.Body["media_attachments"]![0]!.Text("type"));
+
+			var still = (await Upload(alice, "/api/v2/media", frame.WriteToBuffer(".gif"), "image/gif", "still.gif")).Ok();
+			Assert.Equal("image", still.Body.Text("type"));
+		}
+
 		[Fact]
 		public async Task Video_is_remuxed_without_its_metadata()
 		{
@@ -160,7 +226,13 @@ namespace PrivaPub.Tests.Http
 				"-c:v", "mpeg4", "-c:a", "aac", "-shortest");
 			Assert.Contains("secret title", Encoding.Latin1.GetString(video));
 
-			var uploaded = (await Upload(alice, "/api/v2/media", video, "video/mp4", "clip.mp4")).Ok();
+			// v2 answers before it is processed: 202, no url yet, and it can't be posted until it is
+			var accepted = await Upload(alice, "/api/v2/media", video, "video/mp4", "clip.mp4");
+			Assert.Equal(HttpStatusCode.Accepted, accepted.Status);
+			Assert.Null(accepted.Body["url"]);
+			Assert.Equal(HttpStatusCode.PartialContent, (await alice.Client.Get($"/api/v1/media/{accepted.Body.Text("id")}")).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/statuses", ("status", "too soon"), ("media_ids[]", accepted.Body.Text("id")))).Status);
+			var uploaded = (await Processed(alice, accepted)).Ok();
 
 			Assert.Equal("video", uploaded.Body.Text("type"));
 			Assert.Equal(320, uploaded.Body["meta"]!["original"].Number("width"));
@@ -168,6 +240,8 @@ namespace PrivaPub.Tests.Http
 			Assert.EndsWith(".jpg", uploaded.Body.Text("preview_url"));
 			var probe = await Probe(uploaded.Body.Text("url"));
 			Assert.Contains("\"codec_type\": \"video\"", probe);
+			// MPEG-4 Part 2, which browsers don't play, made H.264
+			Assert.Contains("\"codec_name\": \"h264\"", probe);
 			Assert.DoesNotContain("secret title", probe);
 			Assert.DoesNotContain("filmed at home", probe);
 			Assert.DoesNotContain("hidden handler", probe);
@@ -180,7 +254,8 @@ namespace PrivaPub.Tests.Http
 			var audio = await Made("m4a", "-f", "lavfi", "-i", "sine=frequency=330:duration=1", "-metadata", "title=secret song", "-metadata", "artist=Alice Smith",
 				"-c:a", "aac");
 
-			var uploaded = (await Upload(alice, "/api/v2/media", audio, "audio/mp4", "song.m4a")).Ok();
+			// v1 waits for it
+			var uploaded = (await Upload(alice, "/api/v1/media", audio, "audio/mp4", "song.m4a")).Ok();
 
 			Assert.Equal("audio", uploaded.Body.Text("type"));
 			var probe = await Probe(uploaded.Body.Text("url"));
@@ -189,6 +264,35 @@ namespace PrivaPub.Tests.Http
 			Assert.DoesNotContain("Alice Smith", probe);
 		}
 
+		// FLAC is served as what it is (ASP.NET's map has no entry for it, so it was a 404)
+		[Fact]
+		public async Task Flac_is_served()
+		{
+			var alice = await _host.Mastodon("alice");
+			var flac = await Made("flac", "-f", "lavfi", "-i", "sine=frequency=500:duration=1", "-c:a", "flac");
+
+			var uploaded = (await Upload(alice, "/api/v1/media", flac, "audio/flac", "song.flac")).Ok();
+
+			var served = await _host.Client().GetAsync(new Uri(uploaded.Body.Text("url")).PathAndQuery, Token);
+			Assert.Equal(HttpStatusCode.OK, served.StatusCode);
+			Assert.Equal("audio/flac", served.Content.Headers.ContentType?.MediaType);
+		}
+
+		// a video larger than video_matrix_limit is made smaller, its shape kept
+		[Fact]
+		public async Task A_video_larger_than_the_limit_is_made_smaller()
+		{
+			var alice = await _host.Mastodon("alice");
+			var video = await Made("mp4", "-f", "lavfi", "-i", "testsrc=duration=1:size=2000x1500:rate=5", "-c:v", "libx264", "-preset", "ultrafast", "-pix_fmt", "yuv420p");
+
+			var uploaded = (await Upload(alice, "/api/v1/media", video, "video/mp4", "big.mp4")).Ok();
+
+			var width = uploaded.Body["meta"]!["original"].Number("width");
+			var height = uploaded.Body["meta"]!["original"].Number("height");
+			Assert.True((long)width * height <= 2_304_000, $"{width}x{height}");
+			Assert.InRange((double)width / height, 1.3, 1.37);
+		}
+
 		static byte[] Bytes(int length)
 		{
 			var bytes = new byte[length];
@@ -311,6 +415,36 @@ namespace PrivaPub.Tests.Http
 			Assert.Single(_peer.Requests);
 		}
 
+		// clients asking at once for a file not cached yet share one download
+		[Fact]
+		public async Task Clients_asking_at_once_share_one_download()
+		{
+			var proxy = _host.Get<IMediaProxy>();
+			var bytes = Bytes(200_000);
+			var remote = Served(bytes, "image/png");
+			var path = new Uri(remote).AbsolutePath;
+			using var client = _host.Client();
+
+			var answers = await Task.WhenAll(Enumerable.Range(0, 5).Select(_ => client.GetAsync(proxy.Wrap(remote), Token)));
+
+			foreach (var answer in answers)
+				Assert.Equal(bytes, await answer.Content.ReadAsByteArrayAsync(Token));
+			Assert.Single(_peer.Requests, r => r.Path == path);
+		}
+
+		// a remote file that can't be had is a 404 no browser keeps
+		[Fact]
+		public async Task A_remote_file_that_fails_is_not_cached_by_browsers()
+		{
+			var proxy = _host.Get<IMediaProxy>();
+			using var client = _host.Client();
+
+			using var missing = await client.GetAsync(proxy.Wrap($"{_peer.A}/media/{Guid.NewGuid():N}.png"), Token);
+
+			Assert.Equal(HttpStatusCode.NotFound, missing.StatusCode);
+			Assert.Null(missing.Headers.CacheControl);
+		}
+
 		[Fact]
 		public async Task Anything_over_the_proxy_limit_is_streamed_and_never_cached()
 		{
@@ -328,7 +462,8 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(default, proxy.Cached(remote));
 			using var again = await client.GetAsync(proxy.Wrap(remote), Token);
 			Assert.Equal(bytes, await again.Content.ReadAsByteArrayAsync(Token));
-			Assert.Equal(4, _peer.Requests.Count);
+			// the first time, an attempt to cache it and the stream; then it is known to be too big, and only streamed
+			Assert.Equal(3, _peer.Requests.Count);
 			var small = Served(Bytes(SmallProxyHost.Limit / 2));
 			using (var fits = await client.GetAsync(proxy.Wrap(small), Token))
 				Assert.Equal(HttpStatusCode.OK, fits.StatusCode);

PrivaPub.Tests/Http/MastodonScheduledStatusesTests.cs

@@ -0,0 +1,158 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Media;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Http
+{
+	// Mastodon's scheduled statuses: a post given a scheduled_at waits as asked, can be moved or dropped, and is
+	// published by its job when its time comes
+	[Trait("Category", "Integration")]
+	public sealed class MastodonScheduledStatusesTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static string In(TimeSpan from) => DateTime.UtcNow.Add(from).ToString("o");
+
+		[Fact]
+		public async Task A_scheduled_post_waits_is_moved_and_is_dropped_by_its_owner_only()
+		{
+			var alice = await _host.Mastodon("alice");
+			var mallory = await _host.Mastodon("mallory");
+
+			var scheduled = (await alice.Client.Post("/api/v1/statuses", ("status", "later, friends"), ("visibility", "unlisted"),
+				("spoiler_text", "soon"), ("scheduled_at", In(TimeSpan.FromMinutes(30))))).Ok().Object;
+			var id = scheduled.Text("id");
+			Assert.Null(scheduled["uri"]);
+			Assert.Equal("later, friends", scheduled["params"].Text("text"));
+			Assert.Equal("unlisted", scheduled["params"].Text("visibility"));
+			Assert.Equal("soon", scheduled["params"].Text("spoiler_text"));
+			Assert.Empty((await alice.Client.Get($"/api/v1/accounts/{alice.Id}/statuses")).Ok().Array);
+			Assert.Equal(new[] { id }, (await alice.Client.Get("/api/v1/scheduled_statuses")).Ok().Ids);
+
+			var later = DateTime.UtcNow.AddHours(2);
+			var moved = (await alice.Client.Put($"/api/v1/scheduled_statuses/{id}", ("scheduled_at", later.ToString("o")))).Ok().Object;
+			Assert.Equal(later.ToString("yyyy-MM-ddTHH:mm"), moved.Text("scheduled_at")[..16]);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity,
+				(await alice.Client.Put($"/api/v1/scheduled_statuses/{id}", ("scheduled_at", In(TimeSpan.FromMinutes(2))))).Status);
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity,
+				(await alice.Client.Post("/api/v1/statuses", ("status", "too soon"), ("scheduled_at", In(TimeSpan.FromMinutes(1))))).Status);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity,
+				(await alice.Client.Post("/api/v1/statuses", ("status", " "), ("scheduled_at", In(TimeSpan.FromHours(1))))).Status);
+			Assert.Empty((await mallory.Client.Get("/api/v1/scheduled_statuses")).Ok().Array);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Get($"/api/v1/scheduled_statuses/{id}")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await mallory.Client.Delete($"/api/v1/scheduled_statuses/{id}")).Status);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _host.Client().Get("/api/v1/scheduled_statuses")).Status);
+
+			(await alice.Client.Delete($"/api/v1/scheduled_statuses/{id}")).Ok();
+			Assert.Empty((await alice.Client.Get("/api/v1/scheduled_statuses")).Ok().Array);
+			await DB.Default.Update<Job>().Match(j => j.Kind == JobKind.PublishScheduled && j.Payload == id)
+				.Modify(j => j.RunAt, DateTime.UtcNow).ExecuteAsync(Token);
+			await _host.Run(j => j.Kind == JobKind.PublishScheduled && j.Payload == id, Token);
+			Assert.Empty((await alice.Client.Get($"/api/v1/accounts/{alice.Id}/statuses")).Ok().Array);
+		}
+
+		[Fact]
+		public async Task A_scheduled_post_is_published_with_its_media_when_its_time_comes()
+		{
+			var alice = await _host.Mastodon("alice");
+			var upload = MastodonHelpers.Multipart(("file", MastodonHelpers.JpegWithMetadata(16, 16), "image/jpeg", "a.jpg"));
+			var mediaId = (await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media") { Content = upload })).Ok().Body.Text("id");
+
+			var id = (await alice.Client.Post("/api/v1/statuses", ("status", "on time"), ("media_ids[]", mediaId), ("poll[options][]", "yes"),
+				("poll[options][]", "no"), ("poll[expires_in]", "3600"), ("scheduled_at", In(TimeSpan.FromMinutes(10))))).Ok().Object.Text("id");
+			Assert.Equal(id, (await DB.Default.Find<MediaAttachment>().MatchID(mediaId).ExecuteFirstAsync(Token)).ScheduledStatusId);
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/statuses", ("status", "same media"), ("media_ids[]", mediaId),
+				("scheduled_at", In(TimeSpan.FromMinutes(20))))).Status);
+
+			// not due yet: its job leaves it waiting
+			Assert.Equal(1, await _host.Run(j => j.Kind == JobKind.PublishScheduled && j.Payload == id, Token));
+			Assert.Single((await alice.Client.Get("/api/v1/scheduled_statuses")).Ok().Array);
+
+			// its time comes (moved into the past, as the clock would have it)
+			await DB.Default.Update<ScheduledStatus>().MatchID(id).Modify(s => s.ScheduledAt, DateTime.UtcNow.AddSeconds(-1)).ExecuteAsync(Token);
+			await DB.Default.Update<Job>().Match(j => j.Kind == JobKind.PublishScheduled && j.Payload == id).Modify(j => j.State, JobState.Pending).ExecuteAsync(Token);
+			await _host.Run(j => j.Kind == JobKind.PublishScheduled && j.Payload == id, Token);
+
+			Assert.Empty((await alice.Client.Get("/api/v1/scheduled_statuses")).Ok().Array);
+			var published = Assert.Single((await alice.Client.Get($"/api/v1/accounts/{alice.Id}/statuses")).Ok().Array)!;
+			Assert.Contains("on time", published.Text("content"));
+			Assert.Equal(mediaId, Assert.Single(published["media_attachments"]!.AsArray()).Text("id"));
+			Assert.Equal(2, published["poll"]!["options"]!.AsArray().Count);
+			var media = await DB.Default.Find<MediaAttachment>().MatchID(mediaId).ExecuteFirstAsync(Token);
+			Assert.Equal(published.Text("id"), media.PostId);
+			Assert.Null(media.ScheduledStatusId);
+		}
+
+		async Task<string> Picture(Mastodon account)
+		{
+			var upload = MastodonHelpers.Multipart(("file", MastodonHelpers.JpegWithMetadata(16, 16), "image/jpeg", "a.jpg"));
+			return (await account.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media") { Content = upload })).Ok().Body.Text("id");
+		}
+
+		// a scheduled post's media are its alone: a post now, or an edit, can't take them
+		[Fact]
+		public async Task A_scheduled_posts_media_cannot_be_taken_by_a_post_now()
+		{
+			var alice = await _host.Mastodon("alice");
+			var mediaId = await Picture(alice);
+			(await alice.Client.Post("/api/v1/statuses", ("status", "later"), ("media_ids[]", mediaId), ("scheduled_at", In(TimeSpan.FromMinutes(10))))).Ok();
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Post("/api/v1/statuses", ("status", "now"), ("media_ids[]", mediaId))).Status);
+			var plain = (await alice.Client.Post("/api/v1/statuses", ("status", "plain"))).Ok().Body.Text("id");
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, (await alice.Client.Put($"/api/v1/statuses/{plain}", ("status", "edited"), ("media_ids[]", mediaId))).Status);
+			var media = await DB.Default.Find<MediaAttachment>().OneAsync(mediaId, Token);
+			Assert.Null(media.PostId);
+			Assert.NotNull(media.ScheduledStatusId);
+		}
+
+		// two posts asking for the same upload at once: exactly one gets it
+		[Fact]
+		public async Task Two_posts_racing_for_one_upload_never_both_get_it()
+		{
+			var alice = await _host.Mastodon("alice");
+			for (var round = 0; round < 5; round++)
+			{
+				var mediaId = await Picture(alice);
+				var answers = await Task.WhenAll(Enumerable.Range(0, 2).Select(i =>
+					alice.Client.Post("/api/v1/statuses", ("status", $"race {round} {i}"), ("media_ids[]", mediaId))));
+				Assert.Single(answers, a => a.Status == HttpStatusCode.OK);
+				Assert.Single(answers, a => a.Status == HttpStatusCode.UnprocessableEntity);
+			}
+		}
+
+		// a persona deleted since it scheduled a post publishes nothing, and what the post held is trashed
+		[Fact]
+		public async Task A_gone_personas_scheduled_post_never_publishes()
+		{
+			var gone = await _host.Mastodon($"gone{Guid.NewGuid():N}"[..12]);
+			var mediaId = await Picture(gone);
+			var id = (await gone.Client.Post("/api/v1/statuses", ("status", "from beyond"), ("media_ids[]", mediaId), ("scheduled_at", In(TimeSpan.FromMinutes(10))))).Ok().Object.Text("id");
+			await DB.Default.Update<Models.User.Avatar>().MatchID(gone.Persona.Id).Modify(a => a.DeletionAt, DateTime.UtcNow).ExecuteAsync(Token);
+
+			await DB.Default.Update<ScheduledStatus>().MatchID(id).Modify(s => s.ScheduledAt, DateTime.UtcNow.AddSeconds(-1)).ExecuteAsync(Token);
+			await DB.Default.Update<Job>().Match(j => j.Kind == JobKind.PublishScheduled && j.Payload == id).Modify(j => j.RunAt, DateTime.UtcNow).ExecuteAsync(Token);
+			await _host.Run(j => j.Kind == JobKind.PublishScheduled && j.Payload == id, Token);
+
+			Assert.False(await DB.Default.Find<Models.Post.Post>().Match(p => p.GroupUserId == gone.Persona.Id && p.Text == "from beyond").ExecuteAnyAsync(Token));
+			Assert.False(await DB.Default.Find<ScheduledStatus>().Match(s => s.ID == id).ExecuteAnyAsync(Token));
+			Assert.NotNull((await DB.Default.Find<MediaAttachment>().OneAsync(mediaId, Token)).TrashedAt);
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonStatusesTests.cs

@@ -1,3 +1,7 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.User;
 using PrivaPub.Tests.Support;
 using PrivaPub.Tests.Support.Host;
 
@@ -130,6 +134,87 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(1, (await alice.Client.Get($"/api/v1/statuses/{parent.ID}")).Ok().Body.Number("replies_count"));
 		}
 
+		// a remote thread opened by a persona has its replies read from its server (here its FEP-7888 context), at most hourly
+		[Fact]
+		public async Task Opening_a_remote_thread_reads_the_replies_that_never_reached_us()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var carol = new RemoteActor(_peer, "carol");
+			var context = $"{bob.Origin()}/contexts/{Guid.NewGuid():N}";
+			var post = await _host.PublicPostFrom(bob, alice, shape: note => note["context"] = context);
+			var answer = carol.Create("<p>said elsewhere</p>", new[] { MastodonHelpers.Public }, new[] { carol.Id + "/followers" },
+				note => note["inReplyTo"] = post.ObjectURI)["object"]!;
+			var answerId = answer["id"]!.GetValue<string>();
+			_peer.Serve(new Uri(answerId).AbsolutePath, answer.ToJsonString());
+			_peer.Serve(new Uri(context).AbsolutePath, new JsonObject
+			{
+				["id"] = context, ["type"] = "OrderedCollection", ["orderedItems"] = new JsonArray(post.ObjectURI, answerId)
+			}.ToJsonString());
+			async Task<int> Queued() => (await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.FetchReplies && j.Payload.Contains(post.ID)).ExecuteAsync(token)).Count;
+
+			(await _host.Client().Get($"/api/v1/statuses/{post.ID}/context")).Ok();
+			Assert.Equal(0, await Queued());
+			Assert.Empty((await alice.Client.Get($"/api/v1/statuses/{post.ID}/context")).Ok().Body["descendants"]!.AsArray());
+			Assert.Equal(1, await _host.Run(j => j.Kind == JobKind.FetchReplies && j.Payload.Contains(post.ID), token));
+
+			var descendants = (await alice.Client.Get($"/api/v1/statuses/{post.ID}/context")).Ok().Body["descendants"]!.AsArray();
+			Assert.Equal(answerId, Assert.Single(descendants).Text("uri"));
+			Assert.Equal(1, await Queued());
+		}
+
+		// Akkoma marks a post with sensitive media "sensitive" and leaves its summary empty: the media is hidden, the words are
+		// not, and no warning is made up for them (found by decePub's e2e tests on the town)
+		[Fact]
+		public async Task A_remote_post_sensitive_without_a_summary_hides_its_media_and_not_its_words()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			_peer.WebFinger(bob);
+			var post = await _host.PublicPostFrom(bob, alice, shape: note => { note["sensitive"] = true; note["summary"] = ""; });
+
+			var status = (await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body;
+
+			Assert.True(status["sensitive"]!.GetValue<bool>());
+			Assert.Equal("", status.Text("spoiler_text"));
+		}
+
+		// a status asked for by id is shown even when the viewer blocked or muted its author, as Mastodon shows it: only lists
+		// leave such posts out (it once answered 200 with null, and decePub's thread page showed nothing)
+		[Fact]
+		public async Task A_status_of_an_author_the_viewer_blocked_is_still_shown_by_its_id()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			_peer.WebFinger(bob);
+			var post = await _host.PublicPostFrom(bob, alice);
+			var bobId = (await _host.Known(bob)).ID;
+			(await alice.Client.Post($"/api/v1/accounts/{bobId}/block")).Ok();
+
+			var status = (await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body;
+
+			Assert.Equal(post.ID, status.Text("id"));
+		}
+
+		// a reader who deletes the @name decePub prefills still answers its author: GoToSocial dropped such a reply, addressed
+		// to nobody there (found by decePub's e2e tests on the town)
+		[Fact]
+		public async Task A_reply_without_the_authors_name_still_names_the_author_in_cc()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			_peer.WebFinger(bob);
+			var parent = await _host.PublicPostFrom(bob, alice);
+
+			var reply = await alice.Status("no name in this one", ("in_reply_to_id", parent.ID));
+
+			Assert.Empty(reply["mentions"]!.AsArray());
+			var create = Assert.Single(await bob.Delivered(since), d => d.Type() == "Create");
+			Assert.Contains(bob.Id, Strings(create["object"]!["cc"]));
+		}
+
 		[Fact]
 		public async Task A_poll_is_created_validated_and_federated_as_a_question()
 		{
@@ -303,6 +388,100 @@ namespace PrivaPub.Tests.Http
 			Assert.True((await alice.Client.Post($"/api/v1/statuses/{quiet.Text("id")}/favourite")).Ok().Body.Flag("favourited"));
 		}
 
+		// a downvote is a Dislike, one vote a post: a downvote replaces the favourite and a favourite the downvote, each by its
+		// own activity alone; a vote on a post in a community goes to the community, which counts it, and to its author only
+		// when on another server
+		[Fact]
+		public async Task A_downvote_replaces_the_favourite_and_votes_reach_the_posts_community()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob", origin: _peer.B);
+			var community = new RemoteActor(_peer, "pies", type: "Group");
+			await _host.Get<PrivaPub.Federation.Actors.IRemoteActorService>().GetActor(community.Id, refresh: true, TestContext.Current.CancellationToken);
+			var remote = await _host.PublicPostFrom(bob, alice, shape: note => note["audience"] = community.Id);
+			var neighbour = new RemoteActor(_peer, "neighbour");
+			var nearby = await _host.PublicPostFrom(neighbour, alice, shape: note => note["audience"] = community.Id);
+			(await alice.Client.Post($"/api/v1/statuses/{nearby.ID}/favourite")).Ok();
+			Assert.Empty(await neighbour.Delivered(since));
+			var path = $"/api/v1/statuses/{remote.ID}";
+
+			(await alice.Client.Post(path + "/favourite")).Ok();
+			var down = (await alice.Client.Post(path + "/downvote")).Ok().Body;
+			Assert.False(down.Flag("favourited"));
+			Assert.Equal((0, 1, true), (down["privapub"]!["votes"].Number("up"), down["privapub"]!["votes"].Number("down"), down["privapub"]!["votes"].Flag("downvoted")));
+			Assert.Equal(1, (await alice.Client.Post(path + "/downvote")).Ok().Body["privapub"]!["votes"].Number("down"));
+			var up = (await alice.Client.Post(path + "/favourite")).Ok().Body;
+			Assert.Equal((true, 0, false), (up.Flag("favourited"), up["privapub"]!["votes"].Number("down"), up["privapub"]!["votes"].Flag("downvoted")));
+			Assert.Null((await _host.Client().Get(path)).Ok().Body["privapub"]!["votes"]!["downvoted"]);
+			(await alice.Client.Post(path + "/downvote")).Ok();
+			var none = (await alice.Client.Post(path + "/undownvote")).Ok().Body;
+			Assert.Equal((false, 0, 0), (none.Flag("favourited"), none.Number("favourites_count"), none["privapub"]!["votes"].Number("down")));
+
+			foreach (var inbox in new[] { bob, community })
+			{
+				var sent = (await inbox.Delivered(since)).Where(d => (d.Type() == "Undo" ? d["object"].Text("object") : d.Text("object")) == remote.ObjectURI).ToList();
+				Assert.Equal(new[] { "Like", "Dislike", "Like", "Dislike", "Undo:Dislike" },
+					sent.Select(d => d.Type() == "Undo" ? "Undo:" + d["object"].Text("type") : d.Type()));
+				var dislike = sent.Last(d => d.Type() == "Dislike");
+				Assert.Equal((alice.Uri, remote.ObjectURI), (dislike.Text("actor"), dislike.Text("object")));
+				Assert.Equal(dislike.Text("id"), sent.Single(d => d.Type() == "Undo")["object"].Text("id"));
+			}
+		}
+
+		[Fact]
+		public async Task A_favourite_or_a_boost_given_again_after_its_undo_is_a_new_activity_that_is_delivered()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var remote = await _host.PublicPostFrom(bob, alice);
+			var path = $"/api/v1/statuses/{remote.ID}";
+
+			foreach (var (on, off) in new[] { ("favourite", "unfavourite"), ("reblog", "unreblog") })
+			{
+				(await alice.Client.Post($"{path}/{on}")).Ok();
+				(await alice.Client.Post($"{path}/{off}")).Ok();
+				(await alice.Client.Post($"{path}/{on}")).Ok();
+			}
+
+			var sent = await bob.Delivered(since);
+			foreach (var type in new[] { "Like", "Announce" })
+			{
+				var given = sent.Where(d => d.Type() == type).ToList();
+				Assert.Equal(2, given.Count);
+				Assert.NotEqual(given[0].Text("id"), given[1].Text("id"));
+				var undo = Assert.Single(sent, d => d.Type() == "Undo" && d["object"].Text("type") == type);
+				Assert.Equal(given[0].Text("id"), undo["object"].Text("id"));
+			}
+			var status = (await alice.Client.Get(path)).Ok().Body;
+			Assert.True(status.Flag("favourited"));
+			Assert.True(status.Flag("reblogged"));
+			Assert.Equal(1, status.Number("reblogs_count"));
+		}
+
+		[Fact]
+		public async Task A_boost_reaches_the_authors_server_once_through_its_shared_inbox_and_a_like_its_own_inbox()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var remote = await _host.PublicPostFrom(bob, alice);
+			await DB.Default.Update<ForeignAvatar>().Match(f => f.ActorURI == bob.Id).Modify(f => f.SharedInboxURL, bob.SharedInbox)
+				.ExecuteAsync(TestContext.Current.CancellationToken);
+
+			(await alice.Client.Post($"/api/v1/statuses/{remote.ID}/reblog")).Ok();
+			(await alice.Client.Post($"/api/v1/statuses/{remote.ID}/unreblog")).Ok();
+			(await alice.Client.Post($"/api/v1/statuses/{remote.ID}/favourite")).Ok();
+
+			var shared = await Jobs.Deliveries(bob.SharedInbox, since, TestContext.Current.CancellationToken);
+			Assert.Single(shared, d => d.Type() == "Announce");
+			Assert.Single(shared, d => d.Type() == "Undo");
+			var own = await bob.Delivered(since);
+			Assert.DoesNotContain(own, d => d.Type() is "Announce" or "Undo");
+			Assert.Single(own, d => d.Type() == "Like");
+		}
+
 		[Fact]
 		public async Task Bookmarks_are_kept_listed_and_removed()
 		{

PrivaPub.Tests/Http/MastodonStreamingTests.cs

@@ -0,0 +1,165 @@
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Net.WebSockets;
+using System.Text;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Mastodon's streaming API: a WebSocket whose streams are subscribed by message or in the URL, and server-sent events
+	// per stream; each event mapped for its persona, never what it may not see
+	[Trait("Category", "Integration")]
+	public sealed class MastodonStreamingTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		async Task<WebSocket> Connect(Mastodon account, string query = "")
+		{
+			var client = _host.Server.CreateWebSocketClient();
+			var uri = new Uri($"ws://{PrivaPubHost.Host}/api/v1/streaming?access_token={account.Token}{query}");
+			var socket = await client.ConnectAsync(uri, Token);
+			// the subscription is made as the socket opens: give the server a moment to hear it
+			await Task.Delay(200, Token);
+			return socket;
+		}
+
+		static async Task Say(WebSocket socket, JsonObject message) =>
+			await socket.SendAsync(Encoding.UTF8.GetBytes(message.ToJsonString()), WebSocketMessageType.Text, true, Token);
+
+		// the next message for which `wanted` holds, within a few seconds, or null
+		static async Task<JsonObject> Next(WebSocket socket, Func<JsonObject, bool> wanted, int seconds = 5)
+		{
+			using var timeout = CancellationTokenSource.CreateLinkedTokenSource(Token);
+			timeout.CancelAfter(TimeSpan.FromSeconds(seconds));
+			var buffer = new byte[65536];
+			try
+			{
+				while (true)
+				{
+					var text = new StringBuilder();
+					WebSocketReceiveResult received;
+					do
+					{
+						received = await socket.ReceiveAsync(buffer, timeout.Token);
+						text.Append(Encoding.UTF8.GetString(buffer, 0, received.Count));
+					}
+					while (!received.EndOfMessage);
+					if (JsonNode.Parse(text.ToString()) is JsonObject message && wanted(message))
+						return message;
+				}
+			}
+			catch (OperationCanceledException)
+			{
+				return null;
+			}
+		}
+
+		static string Id(JsonObject message) => JsonNode.Parse(message["payload"]!.GetValue<string>())!["id"]!.GetValue<string>();
+
+		[Fact]
+		public async Task Health_is_answered_and_a_stream_needs_a_persona()
+		{
+			var health = await _host.Client().GetAsync("/api/v1/streaming/health", Token);
+			Assert.Equal("OK", await health.Content.ReadAsStringAsync(Token));
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _host.Client().GetAsync("/api/v1/streaming/public", Token)).StatusCode);
+			var instance = (await _host.Client().Get("/api/v2/instance")).Ok().Body;
+			Assert.StartsWith("ws", instance["configuration"]!["urls"]!["streaming"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task The_user_stream_tells_home_posts_notifications_edits_and_deletions()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var carol = await _host.Mastodon("carol");
+			var stranger = await _host.Mastodon("stranger");
+			(await alice.Client.Post($"/api/v1/accounts/{bob.Id}/follow")).Ok();
+			using var socket = await Connect(alice, "&stream=user");
+			using var elsewhere = await Connect(stranger, "&stream=user");
+
+			var post = (await bob.Status("streamed to alice")).Text("id");
+			var update = await Next(socket, m => m.Text("event") == "update");
+			Assert.NotNull(update);
+			Assert.Equal(new[] { "user" }, update!["stream"]!.AsArray().Select(s => s!.GetValue<string>()));
+			Assert.Equal(post, Id(update));
+
+			await carol.Status($"@{alice.UserName} hello there", ("visibility", "direct"));
+			var notification = await Next(socket, m => m.Text("event") == "notification");
+			Assert.Equal("mention", JsonNode.Parse(notification!["payload"]!.GetValue<string>())!.Text("type"));
+
+			(await bob.Client.Put($"/api/v1/statuses/{post}", ("status", "streamed, then edited"))).Ok();
+			var edited = await Next(socket, m => m.Text("event") == "status.update");
+			Assert.Contains("then edited", JsonNode.Parse(edited!["payload"]!.GetValue<string>())!.Text("content"));
+
+			(await bob.Client.Delete($"/api/v1/statuses/{post}")).Ok();
+			Assert.NotNull(await Next(socket, m => m.Text("event") == "delete" && m["payload"]!.GetValue<string>() == post));
+			// a persona whose home never held it hears nothing of it, not even its id
+			Assert.Null(await Next(elsewhere, m => m.Text("event") is "update" or "delete" && m["payload"]!.GetValue<string>().Contains(post), seconds: 2));
+		}
+
+		[Fact]
+		public async Task A_hashtag_stream_subscribed_by_message_tells_public_posts_only_and_never_a_blocked_authors()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var dave = await _host.Mastodon("dave");
+			(await alice.Client.Post($"/api/v1/accounts/{dave.Id}/block")).Ok();
+			var tag = $"st{Guid.NewGuid():N}"[..12];
+			using var socket = await Connect(alice);
+			await Say(socket, new JsonObject { ["type"] = "subscribe", ["stream"] = "hashtag", ["tag"] = tag });
+			await Task.Delay(200, Token);
+
+			await dave.Status($"blocked #{tag}");
+			await bob.Status($"quiet #{tag}", ("visibility", "unlisted"));
+			var open = (await bob.Status($"open #{tag}")).Text("id");
+			var told = await Next(socket, m => m.Text("event") == "update");
+			Assert.Equal(open, Id(told!));
+			Assert.Equal(new[] { "hashtag", tag }, told["stream"]!.AsArray().Select(s => s!.GetValue<string>()));
+			Assert.Null(await Next(socket, m => m.Text("event") == "update", seconds: 2));
+
+			await Say(socket, new JsonObject { ["type"] = "unsubscribe", ["stream"] = "hashtag", ["tag"] = tag });
+			await Task.Delay(200, Token);
+			await bob.Status($"again #{tag}");
+			Assert.Null(await Next(socket, m => m.Text("event") == "update", seconds: 2));
+
+			await Say(socket, new JsonObject { ["type"] = "subscribe", ["stream"] = "list", ["list"] = "000000000000000000000000" });
+			Assert.Equal("Unknown list", (await Next(socket, m => m["error"] != null))!.Text("error"));
+		}
+
+		[Fact]
+		public async Task Server_sent_events_tell_a_personas_notifications()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			using var request = new HttpRequestMessage(HttpMethod.Get, "/api/v1/streaming/user/notification");
+			request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", alice.Token);
+			using var response = await _host.Client().SendAsync(request, HttpCompletionOption.ResponseHeadersRead, Token);
+			Assert.Equal("text/event-stream", response.Content.Headers.ContentType!.MediaType);
+			using var reader = new StreamReader(await response.Content.ReadAsStreamAsync(Token));
+			Assert.Equal(":)", await reader.ReadLineAsync(Token));
+
+			(await bob.Client.Post($"/api/v1/accounts/{alice.Id}/follow")).Ok();
+			using var timeout = CancellationTokenSource.CreateLinkedTokenSource(Token);
+			timeout.CancelAfter(TimeSpan.FromSeconds(5));
+			string line;
+			while ((line = await reader.ReadLineAsync(timeout.Token)) != null && line != "event: notification")
+			{
+			}
+			Assert.Equal("event: notification", line);
+			var data = await reader.ReadLineAsync(timeout.Token);
+			Assert.Equal("follow", JsonNode.Parse(data!["data: ".Length..])!.Text("type"));
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonTagsTests.cs

@@ -0,0 +1,89 @@
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Hashtags: a tag's week of use in public posts, and followed tags, whose public posts come to the persona's home
+	[Trait("Category", "Integration")]
+	public sealed class MastodonTagsTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		Peer _peer;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		static string NewTag() => $"t{Guid.NewGuid():N}"[..12];
+
+		[Fact]
+		public async Task A_tag_shows_its_week_of_public_use_and_whether_the_persona_follows_it()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var tag = NewTag();
+			await alice.Status($"about #{tag}");
+			await alice.Status($"more about #{tag.ToUpperInvariant()}");
+			await bob.Status($"also #{tag}");
+			await bob.Status($"quietly #{tag}", ("visibility", "unlisted"));
+
+			var shown = (await _host.Client().Get($"/api/v1/tags/{tag}")).Ok().Object;
+			Assert.Equal(tag, shown.Text("name"));
+			Assert.False(shown.Flag("following"));
+			var history = shown["history"]!.AsArray();
+			Assert.Equal(7, history.Count);
+			Assert.Equal(("3", "2"), (history[0].Text("uses"), history[0].Text("accounts")));
+			Assert.Equal(new DateTimeOffset(DateTime.UtcNow.Date, TimeSpan.Zero).ToUnixTimeSeconds().ToString(), history[0].Text("day"));
+
+			Assert.True((await alice.Client.Post($"/api/v1/tags/{tag}/follow")).Ok().Body.Flag("following"));
+			Assert.True((await alice.Client.Get($"/api/v1/tags/%23{tag.ToUpperInvariant()}")).Ok().Body.Flag("following"));
+			Assert.Equal(new[] { tag }, (await alice.Client.Get("/api/v1/followed_tags")).Ok().Array.Select(t => t.Text("name")));
+			Assert.False((await bob.Client.Get($"/api/v1/tags/{tag}")).Ok().Body.Flag("following"));
+			Assert.False((await alice.Client.Post($"/api/v1/tags/{tag}/unfollow")).Ok().Body.Flag("following"));
+			Assert.Empty((await alice.Client.Get("/api/v1/followed_tags")).Ok().Array);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _host.Client().Post($"/api/v1/tags/{tag}/follow")).Status);
+		}
+
+		[Fact]
+		public async Task A_followed_tags_public_posts_come_home_from_here_and_from_other_servers()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var carol = await _host.Mastodon("carol");
+			var remote = new RemoteActor(_peer, "dora");
+			var tag = NewTag();
+			(await alice.Client.Post($"/api/v1/tags/{tag}/follow")).Ok();
+
+			var open = (await bob.Status($"news about #{tag}")).Text("id");
+			var quiet = (await bob.Status($"quiet news #{tag}", ("visibility", "unlisted"))).Text("id");
+			var answer = (await bob.Status($"and #{tag} again", ("in_reply_to_id", open))).Text("id");
+			var untagged = (await bob.Status("nothing tagged")).Text("id");
+			var far = await _host.PublicPostFrom(remote, carol, $"<p>far away #{tag}</p>", note => note["tag"]!.AsArray().Add(new JsonObject
+			{
+				["type"] = "Hashtag",
+				["name"] = "#" + tag,
+				["href"] = $"{remote.Origin()}/tags/{tag}"
+			}));
+
+			var home = (await alice.Client.Get("/api/v1/timelines/home?limit=40")).Ok().Ids.ToList();
+			Assert.Contains(open, home);
+			Assert.Contains(far.ID, home);
+			Assert.DoesNotContain(quiet, home);
+			Assert.DoesNotContain(answer, home);
+			Assert.DoesNotContain(untagged, home);
+			Assert.DoesNotContain(open, (await carol.Client.Get("/api/v1/timelines/home?limit=40")).Ok().Ids);
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonTimelinesTests.cs

@@ -105,14 +105,6 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal(new[] { later, open }, (await alice.Client.Get($"/api/v1/timelines/tag/%23{tag}")).Ok().Ids);
 		}
 
-		[Fact]
-		public async Task A_list_timeline_is_an_empty_stub()
-		{
-			var alice = await _host.Mastodon("alice");
-
-			Assert.Empty((await alice.Client.Get("/api/v1/timelines/list/anything")).Ok().Array);
-		}
-
 		[Fact]
 		public async Task Favourites_list_what_the_persona_liked_newest_first()
 		{
@@ -154,6 +146,43 @@ namespace PrivaPub.Tests.Http
 			Assert.DoesNotContain(answer, (await stranger.Client.Get($"/api/v1/accounts/{bob.Id}/statuses")).Ok().Ids);
 		}
 
+		[Fact]
+		public async Task Conversations_page_by_their_newest_message_and_know_what_is_unread_read_and_removed()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var carol = await _host.Mastodon("carol");
+			await bob.Status($"@{alice.UserName} first", ("visibility", "direct"));
+			var fromCarol = (await carol.Status($"@{alice.UserName} second", ("visibility", "direct"))).Text("id");
+			// writing in a conversation reads it
+			await alice.Status($"@{bob.UserName} third", ("visibility", "direct"));
+			async Task<JsonArray> List() => (await alice.Client.Get("/api/v1/conversations")).Ok().Array;
+
+			var all = await List();
+			Assert.Equal(2, all.Count);
+			var (withBob, withCarol) = (all[0].Text("id"), all[1].Text("id"));
+			Assert.Equal(new[] { bob.Id }, all[0]!["accounts"]!.AsArray().Select(a => a.Text("id")));
+			Assert.False(all[0].Flag("unread"));
+			Assert.True(all[1].Flag("unread"));
+			Assert.Equal(fromCarol, all[1]!["last_status"].Text("id"));
+
+			var page = (await alice.Client.Get("/api/v1/conversations?limit=1")).Ok();
+			Assert.Equal(withBob, Assert.Single(page.Array).Text("id"));
+			Assert.Equal(withCarol, Assert.Single((await alice.Client.Get(page.Link("next"))).Ok().Array).Text("id"));
+
+			Assert.False((await alice.Client.Post($"/api/v1/conversations/{withCarol}/read")).Ok().Body.Flag("unread"));
+			Assert.False((await List()).Single(c => c.Text("id") == withCarol).Flag("unread"));
+
+			// off the list until a newer message, which brings it back unread; carol's own list never changed
+			(await alice.Client.Delete($"/api/v1/conversations/{withCarol}")).Ok();
+			Assert.Equal(new[] { withBob }, (await List()).Select(c => c.Text("id")));
+			Assert.Equal(withCarol, Assert.Single((await carol.Client.Get("/api/v1/conversations")).Ok().Array).Text("id"));
+			var again = (await carol.Status($"@{alice.UserName} are you there?", ("visibility", "direct"))).Text("id");
+			var back = (await List())[0];
+			Assert.Equal((withCarol, again, true), (back.Text("id"), back!["last_status"].Text("id"), back.Flag("unread")));
+			Assert.Equal(HttpStatusCode.NotFound, (await bob.Client.Delete($"/api/v1/conversations/{withCarol}")).Status);
+		}
+
 		[Fact]
 		public async Task Markers_are_saved_versioned_and_read_back_per_timeline()
 		{

PrivaPub.Tests/Http/MastodonTrendsTests.cs

@@ -0,0 +1,133 @@
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Social;
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+namespace PrivaPub.Tests.Http
+{
+	// Trends from what PrivaPub holds (hashtags and links by how many authors use them, posts by their interactions,
+	// from discoverable authors only) and the directory of accounts that let themselves be discovered
+	[Trait("Category", "Integration")]
+	public sealed class MastodonTrendsTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		void Fresh() => _host.Get<Trends>().Forget();
+
+		static string NewTag() => $"tr{Guid.NewGuid():N}"[..12];
+
+		[Fact]
+		public async Task A_hashtag_trends_once_two_authors_use_it_today_and_never_from_one_or_behind_a_warning()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var carol = await _host.Mastodon("carol");
+			var shared = NewTag();
+			var lonely = NewTag();
+			var warned = NewTag();
+			await alice.Status($"#{shared} is good");
+			await bob.Status($"#{shared} indeed");
+			for (var i = 0; i < 4; i++)
+				await carol.Status($"#{lonely} again {i}");
+			await alice.Status($"#{warned}", ("spoiler_text", "careful"));
+			await bob.Status($"#{warned}", ("spoiler_text", "careful"));
+			Fresh();
+
+			var trends = (await _host.Client().Get("/api/v1/trends/tags?limit=20")).Ok().Array;
+			var trend = Assert.Single(trends, t => t.Text("name") == shared)!;
+			Assert.Equal(("2", "2"), (trend["history"]![0].Text("uses"), trend["history"]![0].Text("accounts")));
+			Assert.DoesNotContain(trends, t => t.Text("name") == lonely);
+			Assert.DoesNotContain(trends, t => t.Text("name") == warned);
+			Assert.Contains((await alice.Client.Get("/api/v1/trends?limit=20")).Ok().Array, t => t.Text("name") == shared);
+		}
+
+		[Fact]
+		public async Task A_post_trends_by_its_interactions_when_its_author_is_discoverable()
+		{
+			var alice = await _host.Mastodon("alice");
+			var hidden = await _host.Mastodon("hidden");
+			var bob = await _host.Mastodon("bob");
+			(await hidden.Client.Patch("/api/v1/accounts/update_credentials", ("discoverable", "false"))).Ok();
+			var liked = (await alice.Status("worth a like")).Text("id");
+			var quiet = (await hidden.Status("worth a like too")).Text("id");
+			var answer = (await alice.Status("a reply", ("in_reply_to_id", liked))).Text("id");
+			foreach (var id in new[] { liked, quiet, answer })
+			{
+				(await bob.Client.Post($"/api/v1/statuses/{id}/favourite")).Ok();
+				(await bob.Client.Post($"/api/v1/statuses/{id}/reblog")).Ok();
+			}
+			Fresh();
+
+			var trending = (await _host.Client().Get("/api/v1/trends/statuses?limit=40")).Ok().Ids.ToList();
+			Assert.Contains(liked, trending);
+			Assert.DoesNotContain(quiet, trending);
+			Assert.DoesNotContain(answer, trending);
+		}
+
+		[Fact]
+		public async Task A_link_trends_once_two_authors_share_it()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = await _host.Mastodon("bob");
+			var url = $"https://news.example/{Guid.NewGuid():N}";
+			foreach (var account in new[] { alice, bob })
+			{
+				var id = (await account.Status($"read {url}")).Text("id");
+				await DB.Default.Update<Post>().MatchID(id).Modify(p => p.Link, new PostLink { Href = url, Title = "The news" }).ExecuteAsync(Token);
+			}
+			Fresh();
+
+			var link = Assert.Single((await _host.Client().Get("/api/v1/trends/links?limit=20")).Ok().Array, l => l.Text("url") == url)!;
+			Assert.Equal("The news", link.Text("title"));
+			Assert.Equal("2", link["history"]![0].Text("accounts"));
+		}
+
+		[Fact]
+		public async Task The_directory_lists_discoverable_accounts_by_activity_or_by_joining_and_never_by_creation()
+		{
+			var alice = await _host.Mastodon("alice");
+			var hidden = await _host.Mastodon("hidden");
+			(await hidden.Client.Patch("/api/v1/accounts/update_credentials", ("discoverable", "false"))).Ok();
+			await hidden.Status("not listed");
+			await alice.Status("listed");
+
+			// by their latest public post, newest first: other tests post too, so the directory is read until alice
+			var active = new List<string>();
+			for (var offset = 0; offset < 4000 && !active.Contains(alice.Id); offset += 80)
+			{
+				var page = (await _host.Client().Get($"/api/v1/directory?order=active&local=true&limit=80&offset={offset}")).Ok().Ids.ToList();
+				active.AddRange(page);
+				if (page.Count < 80)
+					break;
+			}
+			Assert.Contains(alice.Id, active);
+			Assert.DoesNotContain(hidden.Id, active);
+			// by the day each says it joined, newest first: a persona's is its published day, set some days back
+			// (each page in order: other tests make personas between two pages)
+			var joined = new List<System.Text.Json.Nodes.JsonNode>();
+			for (var offset = 0; offset < 4000; offset += 80)
+			{
+				var page = (await _host.Client().Get($"/api/v1/directory?order=new&local=true&limit=80&offset={offset}")).Ok().Array;
+				var days = page.Select(a => a.Text("created_at")[..10]).ToList();
+				Assert.Equal(days.OrderByDescending(d => d, StringComparer.Ordinal), days);
+				joined.AddRange(page!);
+				if (page.Count < 80 || joined.Any(a => a.Text("id") == alice.Id))
+					break;
+			}
+			Assert.Contains(joined, a => a.Text("id") == alice.Id);
+			Assert.DoesNotContain(joined, a => a.Text("id") == hidden.Id);
+		}
+	}
+}

PrivaPub.Tests/Http/MastodonWordSearchTests.cs

@@ -0,0 +1,135 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// Status search by words, as Mastodon scopes it: the persona's own posts and those it boosted, favourited, bookmarked
+	// or was named in, and public posts of authors who let themselves be indexed
+	[Trait("Category", "Integration")]
+	public sealed class MastodonWordSearchTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		[Fact]
+		public async Task Words_find_what_the_persona_wrote_or_touched_and_what_indexable_authors_made_public()
+		{
+			var reader = await _host.Mastodon("reader");
+			var open = await _host.Mastodon("open");
+			var shy = await _host.Mastodon("shy");
+			(await open.Client.Patch("/api/v1/accounts/update_credentials", ("indexable", "true"))).Ok();
+			var word = $"w{Guid.NewGuid():N}"[..12];
+
+			var own = (await reader.Status($"my {word}")).Text("id");
+			var indexed = (await open.Status($"open {word}")).Text("id");
+			var quietIndexed = (await open.Status($"followers {word}", ("visibility", "private"))).Text("id");
+			var unindexed = (await shy.Status($"shy {word}")).Text("id");
+			var liked = (await shy.Status($"liked {word}")).Text("id");
+			var named = (await shy.Status($"@{reader.UserName} about {word}")).Text("id");
+			var warned = (await shy.Status("calm", ("spoiler_text", $"about {word}"))).Text("id");
+			(await reader.Client.Post($"/api/v1/statuses/{liked}/favourite")).Ok();
+			(await reader.Client.Post($"/api/v1/statuses/{warned}/bookmark")).Ok();
+
+			var found = (await reader.Client.Get($"/api/v2/search?q={word}&type=statuses&limit=40")).Ok().Body["statuses"]!.AsArray()
+				.Select(s => s.Text("id")).ToList();
+			Assert.Equal(new[] { warned, named, liked, indexed, own }, found);
+			Assert.DoesNotContain(unindexed, found);
+			Assert.DoesNotContain(quietIndexed, found);
+			Assert.Empty((await _host.Client().Get($"/api/v2/search?q={word}&type=statuses")).Ok().Body["statuses"]!.AsArray());
+			Assert.Equal(new[] { named },
+				(await reader.Client.Get($"/api/v2/search?q={word}&type=statuses&limit=1&offset=1")).Ok().Body["statuses"]!.AsArray().Select(s => s.Text("id")));
+		}
+
+		// FEP-268d: a remote account's searchableBy outranks its indexable, and a post's own outranks its author's
+		[Fact]
+		public async Task A_remote_searchable_by_decides_before_indexable()
+		{
+			var token = TestContext.Current.CancellationToken;
+			await using var peer = await Peer.Start();
+			var reader = await _host.Mastodon("reader");
+			var keeper = await _host.Mastodon("keeper");
+			var word = $"s{Guid.NewGuid():N}"[..12];
+
+			async Task<RemoteActor> Author(string name, bool indexable, Func<RemoteActor, JsonArray> searchableBy)
+			{
+				var author = new RemoteActor(peer, name);
+				var document = author.Document();
+				document["indexable"] = indexable;
+				if (searchableBy != default)
+					document["searchableBy"] = searchableBy(author);
+				peer.Serve($"/users/{author.Name}", document.ToJsonString());
+				await DB.Default.SaveAsync(new Following { AvatarId = keeper.Id, TargetActorURI = author.Id, State = FollowState.Accepted }, token);
+				return author;
+			}
+			async Task<string> Says(RemoteActor author, string text, JsonArray searchableBy = default)
+			{
+				var noteId = $"{peer.A}/notes/{Guid.NewGuid():N}";
+				var note = new JsonObject
+				{
+					["id"] = noteId, ["type"] = "Note", ["attributedTo"] = author.Id, ["content"] = $"<p>{text}</p>",
+					["to"] = new JsonArray(Addressing.Public), ["cc"] = new JsonArray(author.Id + "/followers"), ["published"] = DateTime.UtcNow.ToString("O")
+				};
+				if (searchableBy != default)
+					note["searchableBy"] = searchableBy;
+				using var client = _host.Client();
+				await client.SendAsync(author.SignedPost("/human-centipede", new JsonObject
+				{
+					["id"] = noteId + "/activity", ["type"] = "Create", ["actor"] = author.Id,
+					["to"] = new JsonArray(Addressing.Public), ["cc"] = new JsonArray(author.Id + "/followers"), ["object"] = note
+				}), token);
+				Assert.Equal(1, await _host.RunInbox(noteId + "/activity", token));
+				return (await DB.Default.Find<Models.Post.Post>().Match(p => p.ObjectURI == noteId).ExecuteFirstAsync(token)).ID;
+			}
+
+			var open = await Says(await Author("open", indexable: false, _ => new JsonArray(Addressing.Public)), $"open {word}");
+			var closed = await Says(await Author("closed", indexable: true, _ => new JsonArray()), $"closed {word}");
+			var friendly = await Author("friendly", indexable: false, a => new JsonArray(a.Id + "/followers"));
+			var friends = await Says(friendly, $"friends {word}");
+			var quiet = await Author("quiet", indexable: false, default);
+			var perPost = await Says(quiet, $"per post {word}", new JsonArray(Addressing.Public));
+			var plain = await Says(quiet, $"plain {word}");
+
+			static List<string> Found(JsonNode body) => body["statuses"]!.AsArray().Select(s => s.Text("id")).ToList();
+			var before = Found((await reader.Client.Get($"/api/v2/search?q={word}&type=statuses&limit=40")).Ok().Body);
+			Assert.Contains(open, before);
+			Assert.Contains(perPost, before);
+			Assert.DoesNotContain(closed, before);
+			Assert.DoesNotContain(friends, before);
+			Assert.DoesNotContain(plain, before);
+
+			await DB.Default.SaveAsync(new Following { AvatarId = reader.Id, TargetActorURI = friendly.Id, State = FollowState.Accepted }, token);
+			Assert.Contains(friends, Found((await reader.Client.Get($"/api/v2/search?q={word}&type=statuses&limit=40")).Ok().Body));
+		}
+
+		// a handle asks for its account: no posts sharing its words, and no hashtag made of it
+		[Fact]
+		public async Task A_handle_finds_its_account_and_neither_posts_nor_a_hashtag()
+		{
+			var reader = await _host.Mastodon("reader");
+			var named = await _host.Mastodon("named");
+			await reader.Status($"talking of {named.UserName} here");
+
+			foreach (var q in new[] { $"@{named.UserName}", $"@{named.UserName}@{PrivaPubHost.Host}", $"{named.UserName}@{PrivaPubHost.Host}" })
+			{
+				var body = (await reader.Client.Get($"/api/v2/search?q={Uri.EscapeDataString(q)}")).Ok().Body;
+				Assert.Contains(body["accounts"]!.AsArray(), a => a.Text("id") == named.Id);
+				Assert.Empty(body["statuses"]!.AsArray());
+				Assert.Empty(body["hashtags"]!.AsArray());
+			}
+			Assert.Equal("cats", Assert.Single((await reader.Client.Get("/api/v2/search?q=%23Cats")).Ok().Body["hashtags"]!.AsArray()).Text("name"));
+		}
+	}
+}

PrivaPub.Tests/Http/MediaLifecycleTests.cs

@@ -0,0 +1,234 @@
+using MongoDB.Entities;
+
+using PrivaPub.Domain.Media;
+using PrivaPub.Models.Media;
+using PrivaPub.Services;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Http
+{
+	// A file lives exactly as long as something holds it: a deleted post, an edit leaving media out, a replaced picture and
+	// a removed root each trash theirs, which stops /media/files serving them at once; the janitor deletes them later.
+	[Trait("Category", "Integration")]
+	public sealed class MediaLifecycleTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		async Task<string> Upload(Mastodon account, string name)
+		{
+			var form = MastodonHelpers.Multipart(("file", MastodonHelpers.JpegWithMetadata(64, 48), "image/jpeg", name));
+			return (await account.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media") { Content = form })).Ok().Body.Text("id");
+		}
+
+		async Task<HttpStatusCode> Served(string url) =>
+			(await _host.Client().GetAsync(new Uri(url).PathAndQuery, Token)).StatusCode;
+
+		[Fact]
+		public async Task A_deleted_posts_media_stop_being_served()
+		{
+			var alice = await _host.Mastodon("alice");
+			var id = await Upload(alice, "a.jpg");
+			var status = (await alice.Client.Post("/api/v1/statuses", ("status", "with a picture"), ("media_ids[]", id))).Ok();
+			var url = status.Body["media_attachments"]![0]!["url"]!.GetValue<string>();
+			var preview = status.Body["media_attachments"]![0]!["preview_url"]!.GetValue<string>();
+			Assert.Equal(HttpStatusCode.OK, await Served(url));
+
+			(await alice.Client.Delete($"/api/v1/statuses/{status.Body.Text("id")}")).Ok();
+
+			Assert.Equal(HttpStatusCode.NotFound, await Served(url));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(preview));
+			Assert.Equal("post deleted", (await DB.Default.Find<MediaAttachment>().OneAsync(id, Token)).TrashReason);
+			// the file waits in the trash, beside what /media/files serves
+			var relative = url[(url.IndexOf("/media/files/", StringComparison.Ordinal) + "/media/files/".Length)..];
+			Assert.True(File.Exists(Path.Combine(_host.Get<IMediaService>().TrashRoot, relative)));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(url.Replace("/media/files/", "/media/files/.trash/")));
+		}
+
+		[Fact]
+		public async Task An_edit_that_leaves_media_out_trashes_them()
+		{
+			var alice = await _host.Mastodon("alice");
+			var kept = await Upload(alice, "kept.jpg");
+			var dropped = await Upload(alice, "dropped.jpg");
+			var status = (await alice.Client.Post("/api/v1/statuses", ("status", "two pictures"), ("media_ids[]", kept), ("media_ids[]", dropped))).Ok();
+			var urls = status.Body["media_attachments"]!.AsArray().ToDictionary(m => m!["id"]!.GetValue<string>(), m => m!["url"]!.GetValue<string>());
+
+			(await alice.Client.Put($"/api/v1/statuses/{status.Body.Text("id")}", ("status", "one picture"), ("media_ids[]", kept))).Ok();
+
+			Assert.Equal(HttpStatusCode.OK, await Served(urls[kept]));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(urls[dropped]));
+			Assert.Null((await DB.Default.Find<MediaAttachment>().OneAsync(kept, Token)).TrashedAt);
+			Assert.Equal("edited out", (await DB.Default.Find<MediaAttachment>().OneAsync(dropped, Token)).TrashReason);
+		}
+
+		// a posted picture's description and focus change by editing its post (media_attributes), not by PUT, as on Mastodon
+		[Fact]
+		public async Task An_edit_describes_its_media_again_and_keeps_what_it_is_not_sent()
+		{
+			var alice = await _host.Mastodon("alice");
+			var id = await Upload(alice, "a.jpg");
+			var status = (await alice.Client.Post("/api/v1/statuses", ("status", "described later"), ("media_ids[]", id),
+				("spoiler_text", "a warning"), ("sensitive", "true"), ("language", "it"))).Ok();
+			var statusId = status.Body.Text("id");
+			Assert.Equal(HttpStatusCode.NotFound, (await alice.Client.Put($"/api/v1/media/{id}", ("description", "too late"))).Status);
+
+			var edited = (await alice.Client.Json(HttpMethod.Put, $"/api/v1/statuses/{statusId}", new System.Text.Json.Nodes.JsonObject
+			{
+				["status"] = "described now",
+				["spoiler_text"] = "a warning",
+				["sensitive"] = true,
+				["media_ids"] = new System.Text.Json.Nodes.JsonArray(id),
+				["media_attributes"] = new System.Text.Json.Nodes.JsonArray(new System.Text.Json.Nodes.JsonObject { ["id"] = id, ["description"] = "a red square", ["focus"] = "0.5,0.5" })
+			})).Ok();
+
+			Assert.Equal("a red square", edited.Body["media_attachments"]![0]!.Text("description"));
+			Assert.Equal(0.5, edited.Body["media_attachments"]![0]!["meta"]!["focus"]!["x"]!.GetValue<double>());
+			Assert.Equal("a warning", edited.Body.Text("spoiler_text"));
+			Assert.True(edited.Body["sensitive"]!.GetValue<bool>());
+			Assert.Equal("it", edited.Body.Text("language"));
+			Assert.Equal("a red square", (await DB.Default.Find<MediaAttachment>().OneAsync(id, Token)).Description);
+
+			// an edit that doesn't send media keeps them, described as they were; an empty media_ids takes them away
+			var kept = (await alice.Client.Put($"/api/v1/statuses/{statusId}", ("status", "media kept"))).Ok();
+			Assert.Equal("a red square", kept.Body["media_attachments"]![0]!.Text("description"));
+			var bare = (await alice.Client.Json(HttpMethod.Put, $"/api/v1/statuses/{statusId}", new System.Text.Json.Nodes.JsonObject
+			{
+				["status"] = "no picture now",
+				["media_ids"] = new System.Text.Json.Nodes.JsonArray()
+			})).Ok();
+			Assert.Empty(bare.Body["media_attachments"]!.AsArray());
+			Assert.Equal("edited out", (await DB.Default.Find<MediaAttachment>().OneAsync(id, Token)).TrashReason);
+		}
+
+		[Fact]
+		public async Task A_replaced_avatar_is_trashed_and_a_picture_that_is_not_one_is_refused()
+		{
+			var alice = await _host.Mastodon("alice");
+			async Task<ApiAnswer> Picture(byte[] bytes, string type, string name) =>
+				await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Patch, "/api/v1/accounts/update_credentials")
+				{
+					Content = MastodonHelpers.Multipart(("avatar", bytes, type, name))
+				});
+			var first = (await Picture(MastodonHelpers.JpegWithMetadata(300, 300), "image/jpeg", "one.jpg")).Ok().Body.Text("avatar");
+			var second = (await Picture(MastodonHelpers.JpegWithMetadata(320, 300), "image/jpeg", "two.jpg")).Ok().Body.Text("avatar");
+
+			Assert.NotEqual(first, second);
+			Assert.Equal(HttpStatusCode.NotFound, await Served(first));
+			Assert.Equal(HttpStatusCode.OK, await Served(second));
+			var row = await DB.Default.Find<MediaAttachment>().Match(m => m.ProfileOfAvatarId == alice.Persona.Id && m.Kind == "avatar" && m.TrashedAt == null).ExecuteSingleAsync(Token);
+			Assert.EndsWith(row.FilePath, second);
+
+			// not an image: 422, and the avatar stays as it was
+			var refused = await Picture("<svg xmlns='http://www.w3.org/2000/svg'/>"u8.ToArray(), "image/svg+xml", "x.svg");
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, refused.Status);
+			Assert.Equal(second, (await alice.Client.Get("/api/v1/accounts/verify_credentials")).Ok().Body.Text("avatar"));
+		}
+
+		// Mastodon's DELETE /api/v1/profile/avatar and /header: the picture goes, the default shows again
+		[Fact]
+		public async Task A_picture_is_removed_and_the_default_shows_again()
+		{
+			var alice = await _host.Mastodon($"pic{Guid.NewGuid():N}"[..12]);
+			var form = MastodonHelpers.Multipart(("avatar", MastodonHelpers.JpegWithMetadata(200, 200), "image/jpeg", "me.jpg"),
+				("header", MastodonHelpers.JpegWithMetadata(900, 300), "image/jpeg", "top.jpg"));
+			var set = (await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Patch, "/api/v1/accounts/update_credentials") { Content = form })).Ok();
+			var avatar = set.Body.Text("avatar");
+			var header = set.Body.Text("header");
+
+			var removed = (await alice.Client.Delete("/api/v1/profile/avatar")).Ok();
+
+			Assert.Contains("missing", removed.Body.Text("avatar"));
+			Assert.Equal(header, removed.Body.Text("header"));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(avatar));
+			Assert.Equal(HttpStatusCode.OK, await Served(header));
+
+			Assert.Contains("missing", (await alice.Client.Delete("/api/v1/profile/header")).Ok().Body.Text("header"));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(header));
+			Assert.False(await DB.Default.Find<MediaAttachment>().Match(m => m.ProfileOfAvatarId == alice.Persona.Id && m.TrashedAt == null).ExecuteAnyAsync(Token));
+		}
+
+		[Fact]
+		public async Task A_removed_roots_media_and_pictures_are_trashed_and_its_scheduled_posts_dropped()
+		{
+			var gone = await _host.Mastodon($"gone{Guid.NewGuid():N}"[..12]);
+			var posted = await Upload(gone, "posted.jpg");
+			var url = (await gone.Client.Post("/api/v1/statuses", ("status", "soon gone"), ("media_ids[]", posted))).Ok()
+				.Body["media_attachments"]![0]!["url"]!.GetValue<string>();
+			var held = await Upload(gone, "held.jpg");
+			(await gone.Client.Post("/api/v1/statuses", ("status", "later"), ("media_ids[]", held),
+				("scheduled_at", DateTime.UtcNow.AddHours(2).ToString("O")))).Ok();
+			var avatar = (await gone.Client.Exchange(new HttpRequestMessage(HttpMethod.Patch, "/api/v1/accounts/update_credentials")
+			{
+				Content = MastodonHelpers.Multipart(("avatar", MastodonHelpers.JpegWithMetadata(200, 200), "image/jpeg", "me.jpg"))
+			})).Ok().Body.Text("avatar");
+
+			Assert.True(await _host.Get<IRootRemoval>().Remove(gone.Persona.Root.Id, Token));
+
+			Assert.Equal(HttpStatusCode.NotFound, await Served(url));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(avatar));
+			Assert.False(await DB.Default.Find<MediaAttachment>().Match(m => m.OwnerAvatarId == gone.Persona.Id && m.TrashedAt == null).ExecuteAnyAsync(Token));
+			Assert.False(await DB.Default.Find<Models.Social.ScheduledStatus>().Match(s => s.AvatarId == gone.Persona.Id).ExecuteAnyAsync(Token));
+		}
+
+		// what a login's media take: every persona's uploads and pictures, trashed ones no longer
+		[Fact]
+		public async Task A_logins_storage_counts_what_its_personas_keep()
+		{
+			var alice = await _host.Mastodon($"store{Guid.NewGuid():N}"[..12]);
+			using var root = _host.As(alice.Persona.Root.Jwt);
+			async Task<System.Text.Json.Nodes.JsonObject> Storage() => await (await root.GetAsync("/clientapi/user/storage", Token)).JsonBody();
+			Assert.Equal(0, Storage().Result["mediaBytes"]!.GetValue<long>());
+
+			var id = await Upload(alice, "a.jpg");
+			var stored = await Storage();
+			Assert.True(stored["mediaBytes"]!.GetValue<long>() > 0);
+			Assert.Equal(1, stored["mediaFiles"]!.GetValue<long>());
+			Assert.Null(stored["quotaBytes"]);
+
+			await _host.Get<IMediaService>().Trash(m => m.ID == id, "test", Token);
+			Assert.Equal(0, (await Storage())["mediaFiles"]!.GetValue<long>());
+		}
+
+		[Fact]
+		public async Task The_audit_adopts_todays_pictures_and_trashes_what_nothing_holds()
+		{
+			var media = _host.Get<IMediaService>();
+			var bob = await _host.Mastodon($"bob{Guid.NewGuid():N}"[..12]);
+			// a picture shown from before pictures had rows, and a leftover nothing holds
+			var picture = $"2020/01/{Guid.NewGuid():N}.jpg";
+			var leftover = $"2020/01/{Guid.NewGuid():N}.jpg";
+			foreach (var relative in new[] { picture, leftover })
+			{
+				Directory.CreateDirectory(Path.GetDirectoryName(Path.Combine(media.Root, relative))!);
+				await File.WriteAllBytesAsync(Path.Combine(media.Root, relative), new byte[] { 1, 2, 3 }, Token);
+			}
+			await DB.Default.Update<Models.User.Avatar>().MatchID(bob.Persona.Id).Modify(a => a.PictureURL, media.Url(picture)).ExecuteAsync(Token);
+
+			var looked = await MediaAudit.Run(media, fix: false, Token);
+			Assert.True(looked.Adopted >= 1);
+			Assert.True(looked.Unheld >= 1);
+			Assert.True(File.Exists(Path.Combine(media.Root, leftover)));
+
+			await MediaAudit.Run(media, fix: true, Token);
+
+			Assert.True(await DB.Default.Find<MediaAttachment>().Match(m => m.ProfileOfAvatarId == bob.Persona.Id && m.FilePath == picture && m.TrashedAt == null).ExecuteAnyAsync(Token));
+			Assert.Equal(HttpStatusCode.OK, await Served(media.Url(picture)));
+			Assert.Equal(HttpStatusCode.NotFound, await Served(media.Url(leftover)));
+			Assert.True(File.Exists(Path.Combine(media.TrashRoot, leftover)));
+			Assert.True(await DB.Default.Find<MediaAttachment>().Match(m => m.FilePath == leftover && m.TrashedAt != null).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Http/MessageSignatureTests.cs

@@ -0,0 +1,103 @@
+using MongoDB.Entities;
+
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Features;
+
+using PrivaPub.Federation.Signing;
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// RFC 9421 message signatures, as WordPress's ActivityPub plugin, Ghost and Fedify send them first: a delivery so signed
+	// is taken in one request, and refused when its body or its target is not what was signed
+	[Trait("Category", "Integration")]
+	public sealed class MessageSignatureTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		Peer _peer;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task A_delivery_signed_as_rfc9421_is_taken_and_one_whose_body_or_target_differs_is_refused()
+		{
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var create = bob.Create("<p>signed the new way</p>", new[] { alice.Uri });
+			var noteId = create["object"]!["id"]!.GetValue<string>();
+			using var client = _host.Client();
+
+			var tampered = bob.MessageSignedPost(alice.Mouth, create);
+			tampered.Content = new ByteArrayContent(Encoding.UTF8.GetBytes(create.ToJsonString().Replace("new way", "other way")));
+			tampered.Content.Headers.TryAddWithoutValidation("Content-Type", "application/activity+json");
+			tampered.Content.Headers.TryAddWithoutValidation("Content-Digest", bob.MessageSignedPost(alice.Mouth, create).Content!.Headers.GetValues("Content-Digest").First());
+			Assert.Equal(HttpStatusCode.Unauthorized, (await client.SendAsync(tampered, Token)).StatusCode);
+			var elsewhere = bob.MessageSignedPost(alice.Mouth, create, signedFor: "/human-centipede");
+			Assert.Equal(HttpStatusCode.Unauthorized, (await client.SendAsync(elsewhere, Token)).StatusCode);
+
+			Assert.Equal(HttpStatusCode.Accepted, (await client.SendAsync(bob.MessageSignedPost(alice.Mouth, create), Token)).StatusCode);
+			Assert.Equal(1, await _host.RunInbox(Id(create), Token));
+			Assert.Contains("signed the new way", (await DB.Default.Find<Post>().Match(p => p.ObjectURI == noteId).ExecuteSingleAsync(Token)).ContentHtml);
+		}
+
+		static string Id(JsonObject activity) => activity["id"]!.GetValue<string>();
+
+		// a signed fetch (a GET, no body) verifies the same way, and so does RSA-PSS with SHA-512
+		[Fact]
+		public void A_signed_fetch_and_an_rsa_pss_signature_verify()
+		{
+			using var key = RSA.Create(2048);
+			var message = new HttpRequestMessage(HttpMethod.Get, "https://privapub.test/peasants/alice/scribbles/1");
+			MessageSignatures.Sign(message, "https://peer.example/users/bob#main-key", key.ExportPkcs8PrivateKeyPem(), body: null);
+			var request = Request(message);
+			var signature = RequestSignature.Of(request);
+			Assert.Equal("rfc9421:rsa-v1_5-sha256", signature.Scheme);
+			Assert.Null(signature.Problem(request, body: null));
+			Assert.True(signature.VerifiedBy(key.ExportSubjectPublicKeyInfoPem(), signature.Signed(request, "https://privapub.test")));
+			Assert.False(signature.VerifiedBy(key.ExportSubjectPublicKeyInfoPem(), signature.Signed(request, "https://elsewhere.example")));
+
+			var created = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+			var parameters = $"(\"@method\" \"@target-uri\");created={created};keyid=\"bob\";alg=\"rsa-pss-sha512\"";
+			var signatureBase = $"\"@method\": GET\n\"@target-uri\": https://privapub.test/peasants/alice/scribbles/1\n\"@signature-params\": {parameters}";
+			var signed = key.SignData(Encoding.UTF8.GetBytes(signatureBase), HashAlgorithmName.SHA512, RSASignaturePadding.Pss);
+			var pss = new HttpRequestMessage(HttpMethod.Get, "https://privapub.test/peasants/alice/scribbles/1");
+			pss.Headers.TryAddWithoutValidation("Signature-Input", $"pss={parameters}");
+			pss.Headers.TryAddWithoutValidation("Signature", $"pss=:{Convert.ToBase64String(signed)}:");
+			var pssRequest = Request(pss);
+			var pssSignature = RequestSignature.Of(pssRequest);
+			Assert.True(pssSignature.VerifiedBy(key.ExportSubjectPublicKeyInfoPem(), pssSignature.Signed(pssRequest, "https://privapub.test")));
+		}
+
+		static HttpRequest Request(HttpRequestMessage message)
+		{
+			var context = new DefaultHttpContext();
+			context.Request.Method = message.Method.Method;
+			context.Request.Host = new HostString(message.RequestUri!.Host);
+			context.Request.Path = message.RequestUri.AbsolutePath;
+			context.Features.Get<IHttpRequestFeature>()!.RawTarget = message.RequestUri.PathAndQuery;
+			foreach (var (name, values) in message.Headers)
+				context.Request.Headers[name] = values.ToArray();
+			return context.Request;
+		}
+	}
+}

PrivaPub.Tests/Http/NotificationPolicyTests.cs

@@ -0,0 +1,119 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Http
+{
+	// Mastodon's notification policy and requests (4.3): accepted by default; a policy filters what strangers, new accounts
+	// or unasked private mentions send into a request per account, which the persona lets in (and that account from then
+	// on) or dismisses; or drops it
+	[Trait("Category", "Integration")]
+	public sealed class NotificationPolicyTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static async Task<IEnumerable<string>> Notifiers(Mastodon persona, string query = "") =>
+			(await persona.Client.Get("/api/v1/notifications" + query)).Ok().Array.Select(n => n!["account"].Text("id"));
+
+		[Fact]
+		public async Task Everything_is_accepted_until_the_persona_chooses()
+		{
+			var alice = await _host.Mastodon("alice");
+			var stranger = await _host.Mastodon("stranger");
+			var post = (await alice.Status("like me")).Text("id");
+
+			var policy = (await alice.Client.Get("/api/v2/notifications/policy")).Ok().Body;
+			(await stranger.Client.Post($"/api/v1/statuses/{post}/favourite")).Ok();
+
+			Assert.Equal(["accept"], new[] { "for_not_following", "for_not_followers", "for_new_accounts", "for_private_mentions", "for_limited_accounts" }
+				.Select(key => policy.Text(key)).Distinct());
+			Assert.Contains(stranger.Id, await Notifiers(alice));
+			Assert.Empty((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+		}
+
+		[Fact]
+		public async Task A_strangers_notifications_wait_in_a_request_which_lets_them_and_the_stranger_in()
+		{
+			var alice = await _host.Mastodon("alice");
+			var friend = await _host.Mastodon("friend");
+			var stranger = await _host.Mastodon("stranger");
+			(await alice.Client.Post($"/api/v1/accounts/{friend.Id}/follow")).Ok();
+			var post = (await alice.Status("like me")).Text("id");
+			var policy = (await alice.Client.Patch("/api/v2/notifications/policy", ("for_not_following", "filter"))).Ok().Body;
+			Assert.Equal("filter", policy.Text("for_not_following"));
+
+			(await friend.Client.Post($"/api/v1/statuses/{post}/favourite")).Ok();
+			(await stranger.Client.Post($"/api/v1/statuses/{post}/favourite")).Ok();
+
+			Assert.Equal([friend.Id], await Notifiers(alice));
+			Assert.Equal(1, (await alice.Client.Get("/api/v1/notifications/unread_count")).Ok().Body["count"]!.GetValue<int>());
+			Assert.DoesNotContain(stranger.Id, (await alice.Client.Get("/api/v2/notifications")).Ok().Body["accounts"]!.AsArray().Select(a => a.Text("id")));
+			var request = Assert.Single((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array)!;
+			Assert.Equal((stranger.Id, "1", post), (request["account"].Text("id"), request.Text("notifications_count"), request["last_status"].Text("id")));
+			var summary = (await alice.Client.Get("/api/v2/notifications/policy")).Ok().Body["summary"]!;
+			Assert.Equal((1, 1), (summary["pending_requests_count"]!.GetValue<int>(), summary["pending_notifications_count"]!.GetValue<int>()));
+			Assert.Equal([stranger.Id], await Notifiers(alice, $"?account_id={stranger.Id}&include_filtered=true"));
+
+			(await alice.Client.Post($"/api/v1/notifications/requests/{request.Text("id")}/accept")).Ok();
+
+			Assert.Contains(stranger.Id, await Notifiers(alice));
+			Assert.Empty((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+			var again = (await alice.Status("like me again")).Text("id");
+			(await stranger.Client.Post($"/api/v1/statuses/{again}/favourite")).Ok();
+			Assert.Equal(2, (await Notifiers(alice, "?types[]=favourite")).Count(id => id == stranger.Id));
+		}
+
+		[Fact]
+		public async Task A_dismissed_request_takes_its_notifications_with_it_and_a_dropped_one_is_never_kept()
+		{
+			var alice = await _host.Mastodon("alice");
+			var stranger = await _host.Mastodon("stranger");
+			var newcomer = await _host.Mastodon("newcomer");
+			var post = (await alice.Status("like me")).Text("id");
+			// (v1 speaks of filtering only)
+			Assert.True((await alice.Client.Put("/api/v1/notifications/policy", ("filter_not_following", "true"))).Ok().Body.Flag("filter_not_following"));
+			(await stranger.Client.Post($"/api/v1/statuses/{post}/favourite")).Ok();
+			var request = Assert.Single((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array)!;
+
+			(await alice.Client.Post($"/api/v1/notifications/requests/{request.Text("id")}/dismiss")).Ok();
+
+			Assert.Empty((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+			Assert.Empty(await Notifiers(alice, $"?account_id={stranger.Id}&include_filtered=true"));
+			Assert.Equal(HttpStatusCode.NotFound, (await alice.Client.Get($"/api/v1/notifications/requests/{request.Text("id")}")).Status);
+
+			(await alice.Client.Patch("/api/v2/notifications/policy", ("for_new_accounts", "drop"))).Ok();
+			(await newcomer.Client.Post($"/api/v1/statuses/{post}/favourite")).Ok();
+			Assert.Empty(await Notifiers(alice, $"?account_id={newcomer.Id}&include_filtered=true"));
+			Assert.Empty((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+		}
+
+		[Fact]
+		public async Task An_unasked_private_mention_is_filtered_and_one_answering_the_persona_is_not()
+		{
+			var alice = await _host.Mastodon("alice");
+			var stranger = await _host.Mastodon("stranger");
+			(await alice.Client.Patch("/api/v2/notifications/policy", ("for_private_mentions", "filter"))).Ok();
+			var asked = (await alice.Status($"@{stranger.UserName} write to me", ("visibility", "direct"))).Text("id");
+
+			await stranger.Status($"@{alice.UserName} hello out of nowhere", ("visibility", "direct"));
+			await stranger.Status($"@{alice.UserName} as you asked", ("visibility", "direct"), ("in_reply_to_id", asked));
+
+			var mentions = (await alice.Client.Get("/api/v1/notifications?types[]=mention")).Ok().Array.Select(n => n!["status"].Text("content")).ToList();
+			Assert.Contains(mentions, c => c.Contains("as you asked"));
+			Assert.DoesNotContain(mentions, c => c.Contains("out of nowhere"));
+			Assert.Single((await alice.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+		}
+	}
+}

PrivaPub.Tests/Http/OneAnswerTests.cs

@@ -0,0 +1,270 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Tests.Support.Host.FederationHelpers;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Tests.Http
+{
+	// Two views of the same fact give one answer (owner decision 2026-10-04: fix the mismatches).
+	[Trait("Category", "Integration")]
+	public sealed class OneAnswerTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		HttpClient _client;
+		Peer _peer;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_client = _host.Client();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			_client?.Dispose();
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		[Fact]
+		public async Task Anyone_may_search_and_only_a_signed_in_reader_resolves_or_pages()
+		{
+			var reader = await _host.Mastodon("searcher");
+
+			Assert.Equal(HttpStatusCode.OK, (await _client.Get("/api/v2/search?q=somebody")).Status);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _client.Get("/api/v2/search?q=somebody&resolve=true")).Status);
+			Assert.Equal(HttpStatusCode.Unauthorized, (await _client.Get("/api/v2/search?q=somebody&offset=5")).Status);
+			Assert.Equal(HttpStatusCode.OK, (await reader.Client.Get("/api/v2/search?q=somebody&offset=5")).Status);
+		}
+
+		[Fact]
+		public async Task A_remote_account_that_deletes_itself_leaves_nothing_in_the_counts()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var author = await _host.Mastodon("liked");
+			var post = await author.Status("like me");
+			var fan = new RemoteActor(_peer, "fickle");
+			var like = new JsonObject
+			{
+				["id"] = $"{fan.Id}#likes/{Guid.NewGuid():N}",
+				["type"] = "Like",
+				["actor"] = fan.Id,
+				["object"] = post.Text("uri")
+			};
+			Assert.Equal(HttpStatusCode.Accepted, (await _client.SendAsync(fan.SignedPost("/human-centipede", like), token)).StatusCode);
+			await _host.RunInbox(like["id"]!.GetValue<string>(), token);
+			Assert.Equal(1, (await author.Client.Get($"/api/v1/statuses/{post.Text("id")}")).Ok().Body.Number("favourites_count"));
+
+			var delete = new JsonObject
+			{
+				["id"] = $"{fan.Id}#delete",
+				["type"] = "Delete",
+				["actor"] = fan.Id,
+				["object"] = fan.Id,
+				["to"] = new JsonArray("https://www.w3.org/ns/activitystreams#Public")
+			};
+			Assert.Equal(HttpStatusCode.Accepted, (await _client.SendAsync(fan.SignedPost("/human-centipede", delete), token)).StatusCode);
+			await _host.RunInbox(delete["id"]!.GetValue<string>(), token);
+
+			Assert.Equal(0, (await author.Client.Get($"/api/v1/statuses/{post.Text("id")}")).Ok().Body.Number("favourites_count"));
+			Assert.Empty((await author.Client.Get($"/api/v1/statuses/{post.Text("id")}/favourited_by")).Ok().Array);
+			Assert.False(await DB.Default.Find<Favourite>().Match(f => f.ActorURI == fan.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Notification>().Match(n => n.FromActorURI == fan.Id).ExecuteAnyAsync(token));
+			Assert.Equal(0, (await author.Client.Get("/api/v1/notifications/unread_count")).Ok().Body.Number("count"));
+		}
+
+		[Fact]
+		public async Task Only_public_and_unlisted_replies_are_counted()
+		{
+			var author = await _host.Mastodon("threadstart");
+			var replier = await _host.Mastodon("replier");
+			var root = await author.Status("say something");
+			var id = root.Text("id");
+
+			await replier.Status("in public", ("in_reply_to_id", id));
+			await replier.Status("quietly", ("in_reply_to_id", id), ("visibility", "unlisted"));
+			await replier.Status("for my followers", ("in_reply_to_id", id), ("visibility", "private"));
+			await replier.Status($"@{author.UserName} just you", ("in_reply_to_id", id), ("visibility", "direct"));
+
+			Assert.Equal(2, (await author.Client.Get($"/api/v1/statuses/{id}")).Ok().Body.Number("replies_count"));
+		}
+
+		[Fact]
+		public async Task A_status_longer_than_advertised_is_refused()
+		{
+			var author = await _host.Mastodon("wordy");
+			var limit = (await _client.Get("/api/v2/instance")).Ok().Body["configuration"]!["statuses"].Number("max_characters");
+
+			var refused = await author.Client.Post("/api/v1/statuses", ("status", new string('a', limit + 1)));
+			var accepted = await author.Client.Post("/api/v1/statuses", ("status", new string('a', limit)));
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, refused.Status);
+			Assert.Equal(HttpStatusCode.OK, accepted.Status);
+		}
+
+		[Fact]
+		public async Task Joining_a_community_by_invitation_is_following_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var owner = await _host.Persona(await _host.SignUp(), "commowner");
+			var joinerRoot = await _host.SignUp("joiner");
+			var joiner = await _host.Persona(joinerRoot, "joiner");
+			var group = await _host.Group(owner, community: true);
+			var groupName = group["userName"]!.GetValue<string>();
+			using var client = _host.As(joinerRoot.Jwt);
+
+			var joined = await client.PostJson("/clientapi/group/join", new { avatarId = joiner.Id, invitationCode = group["invitationCode"]!.GetValue<string>() });
+
+			Assert.Equal(HttpStatusCode.OK, joined.StatusCode);
+			Assert.Equal(1, (await _client.Fetch($"/peasants/{groupName}/groupies")).Json["totalItems"]!.GetValue<int>());
+			Assert.True(await DB.Default.Find<Following>().Match(f => f.AvatarId == joiner.Id && f.State == FollowState.Accepted).ExecuteAnyAsync(token));
+		}
+
+		public static TheoryData<string> AnsweredRoutes() => new()
+		{
+			"/api/v1/directory",
+			"/api/v1/tags/cats",
+			"/api/v1/instance/languages",
+			"/api/v1/instance/translation_languages",
+			"/api/v1/instance/domain_blocks",
+			"/api/v1/instance/privacy_policy",
+			"/api/v1/timelines/link?url=https%3A%2F%2Fexample.org%2F",
+			"/api/v1/accounts/000000000000000000000000/identity_proofs"
+		};
+
+		[Theory]
+		[MemberData(nameof(AnsweredRoutes))]
+		public async Task Mastodon_routes_we_have_nothing_behind_answer_instead_of_404(string path)
+		{
+			Assert.Equal(HttpStatusCode.OK, (await _client.Get(path)).Status);
+		}
+
+		[Fact]
+		public async Task Likes_of_one_post_come_as_one_group_of_notifications()
+		{
+			var author = await _host.Mastodon("grouped");
+			var first = await _host.Mastodon("fanone");
+			var second = await _host.Mastodon("fantwo");
+			var post = await author.Status("like me twice");
+			var id = post.Text("id");
+			await first.Client.Post($"/api/v1/statuses/{id}/favourite");
+			await second.Client.Post($"/api/v1/statuses/{id}/favourite");
+
+			var list = (await author.Client.Get("/api/v2/notifications")).Ok().Body;
+			var group = Assert.Single(list["notification_groups"]!.AsArray(), g => g!.Text("type") == "favourite")!;
+			var key = group.Text("group_key");
+
+			Assert.Equal($"grouped-favourite-{id}", key);
+			// told alone (v1, a stream), each notification names the group it belongs to
+			Assert.All((await author.Client.Get("/api/v1/notifications?types[]=favourite")).Ok().Array, n => Assert.Equal(key, n.Text("group_key")));
+			Assert.Equal(2, group.Number("notifications_count"));
+			Assert.Equal(2, group["sample_account_ids"]!.AsArray().Count);
+			Assert.Equal(id, group.Text("status_id"));
+			Assert.Contains(list["statuses"]!.AsArray(), s => s!.Text("id") == id);
+			Assert.True((await author.Client.Get("/api/v2/notifications/unread_count")).Ok().Body.Number("count") >= 1);
+			Assert.Equal(key, Assert.Single((await author.Client.Get($"/api/v2/notifications/{key}")).Ok().Body["notification_groups"]!.AsArray())!.Text("group_key"));
+			Assert.Equal(2, (await author.Client.Get($"/api/v2/notifications/{key}/accounts")).Ok().Array.Count);
+			// a notifications marker past them reads them
+			var newest = (await author.Client.Get("/api/v1/notifications")).Ok().Ids.First();
+			(await author.Client.Post("/api/v1/markers", ("notifications[last_read_id]", newest))).Ok();
+			Assert.Equal(0, (await author.Client.Get("/api/v2/notifications/unread_count")).Ok().Body.Number("count"));
+			Assert.Equal(0, (await author.Client.Get("/api/v1/notifications/unread_count")).Ok().Body.Number("count"));
+			Assert.Equal(HttpStatusCode.OK, (await author.Client.Post($"/api/v2/notifications/{key}/dismiss")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await author.Client.Get($"/api/v2/notifications/{key}")).Status);
+		}
+
+		[Fact]
+		public async Task A_hashtag_link_opens_a_page_of_public_posts_with_that_tag()
+		{
+			var author = await _host.Mastodon("tagger");
+			var tag = $"tag{Guid.NewGuid():N}"[..16];
+			await author.Status($"about #{tag}");
+			await author.Status($"quietly about #{tag}", ("visibility", "private"));
+
+			var page = await _client.Fetch($"/tags/{tag}", Browser);
+
+			Assert.Equal(HttpStatusCode.OK, page.Status);
+			Assert.Contains("about", page.Text);
+			Assert.DoesNotContain("quietly", page.Text);
+			Assert.Contains("default-src 'none'", page.Response.Headers.GetValues("Content-Security-Policy").Single());
+		}
+
+		[Fact]
+		public async Task A_communitys_announces_resolve_while_the_post_is_shown()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var owner = await _host.Persona(await _host.SignUp(), "announcer");
+			var community = await _host.FederatedGroup(owner, community: true);
+			var post = await _host.Publish(owner, new PrivaPub.Domain.Statuses.StatusDraft { Text = "into the community", PlainText = true, GroupId = community.Id });
+			var kept = await DB.Default.Find<GroupAnnouncement>().Match(a => a.GroupId == community.Id && a.ObjectURI == post.ObjectURI).ExecuteAsync(token);
+			Assert.Equal(2, kept.Count);//the activity, and the object for Mastodon
+
+			foreach (var announcement in kept)
+			{
+				var fetched = await _client.Fetch(PathOf(announcement.ActivityURI));
+				Assert.Equal(HttpStatusCode.OK, fetched.Status);
+				Assert.Equal("Announce", fetched.Json["type"]!.GetValue<string>());
+				Assert.Equal(announcement.ActivityURI, fetched.Json["id"]!.GetValue<string>());
+			}
+			var listed = await _client.Fetch($"/peasants/{community.UserName}/grunts/announce-{post.ID}");
+			Assert.Equal(HttpStatusCode.OK, listed.Status);
+
+			await _host.Remove(owner, post);
+			Assert.Equal(HttpStatusCode.Gone, (await _client.Fetch(PathOf(kept[0].ActivityURI))).Status);
+		}
+
+		[Fact]
+		public async Task A_boost_points_at_the_boosted_posts_page()
+		{
+			var author = await _host.Mastodon("boosted");
+			var booster = await _host.Mastodon("booster");
+			var post = await author.Status("boost me");
+
+			var boost = (await booster.Client.Post($"/api/v1/statuses/{post.Text("id")}/reblog")).Ok().Body;
+
+			Assert.Equal(post.Text("url"), boost.Text("url"));
+			var browser = await _client.Fetch(PathOf(boost.Text("uri")), Browser);
+			Assert.Equal(HttpStatusCode.Redirect, browser.Status);
+		}
+
+		[Fact]
+		public async Task A_remote_accounts_counts_are_what_its_server_publishes()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var reader = await _host.Mastodon("counter");
+			var popular = new RemoteActor(_peer, "popular");
+			_peer.Serve(new Uri(popular.Id).AbsolutePath + "/followers",
+				$$"""{"@context":"https://www.w3.org/ns/activitystreams","id":"{{popular.Id}}/followers","type":"OrderedCollection","totalItems":42}""");
+			var remote = _host.Get<PrivaPub.Federation.Actors.IRemoteActorService>();
+			var account = await remote.GetActor(popular.Id, refresh: true, token);
+
+			await _host.Run(j => j.Kind == PrivaPub.Models.Jobs.JobKind.CountAccount && j.Payload == popular.Id, token);
+
+			var shown = (await reader.Client.Get($"/api/v1/accounts/{account.ID}")).Ok().Body;
+			Assert.Equal(42, shown.Number("followers_count"));
+			Assert.Equal(0, shown.Number("following_count"));
+		}
+
+		[Fact]
+		public async Task Notification_policy_and_requests_answer_a_signed_in_reader()
+		{
+			var reader = await _host.Mastodon("policy");
+
+			Assert.Equal(HttpStatusCode.OK, (await reader.Client.Get("/api/v1/notifications/policy")).Status);
+			Assert.Equal("accept", (await reader.Client.Get("/api/v2/notifications/policy")).Ok().Body.Text("for_not_following"));
+			Assert.Empty((await reader.Client.Get("/api/v1/notifications/requests")).Ok().Array);
+		}
+	}
+}

PrivaPub.Tests/Http/PersonaArchiveTests.cs

@@ -0,0 +1,346 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Jobs;
+using PrivaPub.Models.Media;
+using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.IO.Compression;
+using System.Net;
+using System.Net.Http.Json;
+using System.Text;
+using System.Text.Json.Nodes;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Tests.Http
+{
+	// A persona's archive (owner decision 2026-10-07): exported in Mastodon's layout with nothing of its root, its siblings
+	// or its keys; imported back home without bringing anything back, or into another persona as posts nobody is told of,
+	// once; Mastodon's own archives read too; and hostile ones refused.
+	[Trait("Category", "Integration")]
+	public sealed class PersonaArchiveTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static string Base(Persona persona) => $"/clientapi/persona/{persona.Id}/archive";
+
+		async Task<JsonObject> Status(Persona persona)
+		{
+			using var client = _host.As(persona.Root.Jwt);
+			return (await client.GetFromJsonAsync<JsonObject>(Base(persona), Token))!;
+		}
+
+		async Task<byte[]> Exported(Persona persona)
+		{
+			using var client = _host.As(persona.Root.Jwt);
+			Assert.Equal(HttpStatusCode.Accepted, (await client.PostAsync(Base(persona), null, Token)).StatusCode);
+			await _host.Run(j => j.Kind == JobKind.ExportArchive && j.Payload == persona.Id, Token);
+			Assert.Equal("ready", (await Status(persona))["exportState"]!.GetValue<string>());
+			var ticket = (await (await client.PostAsync(Base(persona) + "/ticket", null, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!;
+			using var anonymous = _host.Client();
+			var response = await anonymous.GetAsync(ticket["url"]!.GetValue<string>(), Token);
+			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+			return await response.Content.ReadAsByteArrayAsync(Token);
+		}
+
+		// uploaded in two pieces, then imported with the parts asked for, the job run: the import's state
+		async Task<(HttpStatusCode Status, JsonObject State)> Imported(Persona persona, byte[] archive, params string[] parts)
+		{
+			using var client = _host.As(persona.Root.Jwt);
+			var upload = (await (await client.PostAsync("/clientapi/persona/archive/uploads", null, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!["id"]!.GetValue<string>();
+			var half = archive.Length / 2;
+			Assert.Equal(HttpStatusCode.OK, (await client.PutAsync($"/clientapi/persona/archive/uploads/{upload}?offset=0", new ByteArrayContent(archive[..half]), Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.OK, (await client.PutAsync($"/clientapi/persona/archive/uploads/{upload}?offset={half}", new ByteArrayContent(archive[half..]), Token)).StatusCode);
+			var asked = await client.PostAsJsonAsync(Base(persona) + "/import", new { uploadId = upload, parts }, Token);
+			if (asked.StatusCode != HttpStatusCode.Accepted)
+				return (asked.StatusCode, default);
+			await _host.Run(j => j.Kind == JobKind.ImportArchive && j.Payload == persona.Id, Token);
+			return (asked.StatusCode, await Status(persona));
+		}
+
+		static int Count(JsonObject state, string what) => state["importCounts"]?[what]?.GetValue<int>() ?? 0;
+
+		static Dictionary<string, string> Texts(byte[] zip)
+		{
+			using var archive = new ZipArchive(new MemoryStream(zip));
+			return archive.Entries.Where(e => e.Name.EndsWith(".json") || e.Name.EndsWith(".csv"))
+				.ToDictionary(e => e.FullName, e => new StreamReader(e.Open()).ReadToEnd());
+		}
+
+		[Fact]
+		public async Task An_archive_holds_the_persona_and_nothing_of_its_root_its_siblings_or_its_keys()
+		{
+			var alice = await _host.Mastodon("alice");
+			var sibling = await _host.Persona(alice.Persona.Root, "sibling");
+			var bob = await _host.Mastodon("bob");
+			var picture = (await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media")
+			{
+				Content = MastodonHelpers.Multipart(("file", MastodonHelpers.JpegWithMetadata(64, 48), "image/jpeg", "dot.jpg"))
+			})).Ok().Body.Text("id");
+			var first = await alice.Status("a public post with a picture #archives", ("media_ids[]", picture));
+			await alice.Status("for my followers only", ("visibility", "private"));
+			await alice.Status("a reply to myself", ("in_reply_to_id", first.Text("id")));
+			await alice.Client.Post($"/api/v1/statuses/{first.Text("id")}/bookmark");
+			await alice.Client.Post($"/api/v1/statuses/{first.Text("id")}/pin");
+			await alice.Client.Post($"/api/v1/accounts/{bob.Persona.Id}/block");
+			await alice.Client.Post("/api/v1/domain_blocks", ("domain", "spam.example"));
+			await alice.Client.Post("/api/v1/tags/archives/follow");
+
+			var zip = await Exported(alice.Persona);
+			var texts = Texts(zip);
+
+			foreach (var file in new[] { "actor.json", "outbox.json", "likes.json", "bookmarks.json", "following_accounts.csv", "blocked_accounts.csv",
+				"muted_accounts.csv", "blocked_domains.csv", "lists.csv", "bookmarks.csv", "privapub/archive.json", "privapub/pins.json",
+				"privapub/followed_tags.json", "privapub/filters.json", "privapub/notification_policy.json" })
+				Assert.True(texts.ContainsKey(file), $"{file} is missing");
+			using (var archive = new ZipArchive(new MemoryStream(zip)))
+				Assert.Contains(archive.Entries, e => e.FullName.StartsWith("media_attachments/files/", StringComparison.Ordinal));
+			var outbox = JsonNode.Parse(texts["outbox.json"])!["orderedItems"]!.AsArray();
+			Assert.Equal(3, outbox.Count);
+			Assert.Contains(outbox, i => i!["object"]!["attachment"]?[0]?["url"]?.GetValue<string>().StartsWith("/media_attachments/files/") == true);
+			Assert.Contains(bob.Persona.UserName, texts["blocked_accounts.csv"]);
+			Assert.Contains("spam.example", texts["blocked_domains.csv"]);
+			Assert.Contains(first.Text("uri"), texts["privapub/pins.json"]);
+
+			var avatar = await DB.Default.Find<Avatar>().MatchID(alice.Persona.Id).ExecuteFirstAsync(Token);
+			var root = await DB.Default.Find<RootUser>().MatchID(alice.Persona.Root.Id).ExecuteFirstAsync(Token);
+			var all = string.Concat(texts.Values);
+			Assert.DoesNotContain(avatar.PrivateKey.Split('\n')[1], all);
+			Assert.DoesNotContain(avatar.SigningKey, all);
+			Assert.DoesNotContain(root.UserName, all);
+			Assert.DoesNotContain(root.HashedPassword, all);
+			Assert.DoesNotContain(sibling.UserName, all);
+			Assert.DoesNotContain(alice.Token, all);
+		}
+
+		[Fact]
+		public async Task Back_home_an_archive_brings_nothing_back()
+		{
+			var alice = await _host.Mastodon("alice");
+			await alice.Status("kept");
+			var regretted = await alice.Status("regretted");
+			var zip = await Exported(alice.Persona);
+			await alice.Client.Delete($"/api/v1/statuses/{regretted.Text("id")}");
+			var before = await DB.Default.CountAsync<PostEntity>(p => p.GroupUserId == alice.Persona.Id, Token);
+
+			var (status, state) = await Imported(alice.Persona, zip, "posts", "pins");
+
+			Assert.Equal(HttpStatusCode.Accepted, status);
+			Assert.Equal("done", state["importState"]!.GetValue<string>());
+			Assert.True(state["importSameActor"]!.GetValue<bool>());
+			Assert.Equal((0, 1, 1), (Count(state, "posts"), Count(state, "posts already here"), Count(state, "posts deleted here")));
+			Assert.Equal(before, await DB.Default.CountAsync<PostEntity>(p => p.GroupUserId == alice.Persona.Id, Token));
+			Assert.NotNull((await DB.Default.Find<PostEntity>().MatchID(regretted.Text("id")).ExecuteFirstAsync(Token)).DeletedAt);
+		}
+
+		[Fact]
+		public async Task Into_another_persona_posts_arrive_once_and_nobody_is_told()
+		{
+			var alice = await _host.Mastodon("alice");
+			var follower = await _host.Mastodon("follower");
+			var picture = (await alice.Client.Exchange(new HttpRequestMessage(HttpMethod.Post, "/api/v2/media")
+			{
+				Content = MastodonHelpers.Multipart(("file", MastodonHelpers.JpegWithMetadata(64, 48), "image/jpeg", "dot.jpg"))
+			})).Ok().Body.Text("id");
+			var first = await alice.Status("the first words #moving", ("media_ids[]", picture));
+			await alice.Status("and a reply to them", ("in_reply_to_id", first.Text("id")));
+			await _host.Located(alice, "here and nowhere else");
+			var zip = await Exported(alice.Persona);
+
+			var carol = await _host.Mastodon("carol");
+			await follower.Client.Post($"/api/v1/accounts/{carol.Persona.Id}/follow");
+			var actor = $"/peasants/{carol.Persona.UserName}";
+			var jobs = await DB.Default.CountAsync<Job>(j => j.Kind == JobKind.Deliver && j.Payload.Contains(actor), Token);
+			var (_, state) = await Imported(carol.Persona, zip, "posts", "pins", "tags", "located");
+
+			Assert.Equal("done", state["importState"]!.GetValue<string>());
+			Assert.False(state["importSameActor"]!.GetValue<bool>());
+			Assert.Equal(2, Count(state, "posts"));
+			Assert.Equal(1, Count(state, "media"));
+			Assert.Equal(1, Count(state, "located posts"));
+			var copies = await DB.Default.Find<PostEntity>().Match(p => p.GroupUserId == carol.Persona.Id && p.Visibility != Models.Post.PostVisibility.LocalGeo).ExecuteAsync(Token);
+			Assert.Equal(2, copies.Count);
+			var copy = copies.Single(p => p.ImportedFromURI == first.Text("uri"));
+			Assert.StartsWith($"{PrivaPubHost.Base}/peasants/{carol.Persona.UserName}/scribbles/", copy.ObjectURI);
+			Assert.Equal(["moving"], copy.Tags);
+			Assert.Single(copy.Media);
+			Assert.Equal(carol.Persona.Id, (await DB.Default.Find<MediaAttachment>().MatchID(copy.Media[0].AttachmentId).ExecuteFirstAsync(Token)).OwnerAvatarId);
+			var reply = copies.Single(p => p.ID != copy.ID);
+			Assert.Equal(copy.ID, reply.AnsweringToPostId);
+			Assert.Equal(copy.ObjectURI + "/context", reply.ContextURI);
+
+			// nobody told: no delivery, no home, no notification; on the profile all the same
+			Assert.Equal(jobs, await DB.Default.CountAsync<Job>(j => j.Kind == JobKind.Deliver && j.Payload.Contains(actor), Token));
+			var ids = copies.Select(p => p.ID).ToList();
+			Assert.False(await DB.Default.Find<TimelineEntry>().Match(e => ids.Contains(e.PostId)).ExecuteAnyAsync(Token));
+			Assert.Contains((await carol.Client.Get($"/api/v1/accounts/{carol.Persona.Id}/statuses")).Ok().Body!.AsArray(), s => s!.Text("id") == copy.ID);
+
+			// twice changes nothing
+			var (_, again) = await Imported(carol.Persona, zip, "posts", "located");
+			Assert.Equal((0, 2, 1), (Count(again, "posts"), Count(again, "posts already here"), Count(again, "located posts already here")));
+			Assert.Equal(3, await DB.Default.CountAsync<PostEntity>(p => p.GroupUserId == carol.Persona.Id, Token));
+		}
+
+		// Mastodon's own archive: its posts, not its boosts nor its direct messages
+		[Fact]
+		public async Task A_mastodon_archive_is_read()
+		{
+			var dave = await _host.Mastodon("dave");
+			const string actor = "https://mastodon.example/users/dave";
+			const string Public = "https://www.w3.org/ns/activitystreams#Public";
+			var outbox = new JsonObject
+			{
+				["@context"] = "https://www.w3.org/ns/activitystreams",
+				["id"] = "outbox.json",
+				["type"] = "OrderedCollection",
+				["orderedItems"] = new JsonArray(
+					Create(actor, "1", "<p>hello from <b>Mastodon</b><script>alert(1)</script></p>", [Public], [actor + "/followers"], "2023-04-01T10:00:00Z"),
+					Create(actor, "2", "<p>only for one</p>", ["https://elsewhere.example/users/x"], [], "2023-04-02T10:00:00Z"),
+					new JsonObject { ["type"] = "Announce", ["actor"] = actor, ["object"] = "https://elsewhere.example/notes/9" })
+			};
+			var zip = Zip(("actor.json", new JsonObject { ["id"] = actor, ["type"] = "Person", ["followers"] = actor + "/followers" }.ToJsonString()),
+				("outbox.json", outbox.ToJsonString()));
+
+			var (_, state) = await Imported(dave.Persona, zip, "posts");
+
+			Assert.Equal("done", state["importState"]!.GetValue<string>());
+			Assert.Equal((1, 1, 1), (Count(state, "posts"), Count(state, "boosts skipped"), Count(state, "direct or circle posts skipped")));
+			var post = await DB.Default.Find<PostEntity>().Match(p => p.GroupUserId == dave.Persona.Id).ExecuteFirstAsync(Token);
+			Assert.Equal(actor + "/statuses/1", post.ImportedFromURI);
+			Assert.Equal(new DateTime(2023, 4, 1, 10, 0, 0, DateTimeKind.Utc), post.CreationDate);
+			Assert.DoesNotContain("<script", post.ContentHtml);
+			Assert.Contains("Mastodon", post.ContentHtml);
+		}
+
+		static JsonObject Create(string actor, string id, string content, string[] to, string[] cc, string published) => new()
+		{
+			["type"] = "Create",
+			["actor"] = actor,
+			["object"] = new JsonObject
+			{
+				["id"] = $"{actor}/statuses/{id}",
+				["type"] = "Note",
+				["attributedTo"] = actor,
+				["content"] = content,
+				["published"] = published,
+				["to"] = new JsonArray(to.Select(t => (JsonNode)t).ToArray()),
+				["cc"] = new JsonArray(cc.Select(c => (JsonNode)c).ToArray())
+			}
+		};
+
+		static byte[] Zip(params (string Name, string Text)[] files)
+		{
+			var stream = new MemoryStream();
+			using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, leaveOpen: true))
+				foreach (var (name, text) in files)
+				{
+					using var entry = archive.CreateEntry(name).Open();
+					entry.Write(Encoding.UTF8.GetBytes(text));
+				}
+			return stream.ToArray();
+		}
+
+		[Theory]
+		[InlineData("escape")]
+		[InlineData("twice")]
+		[InlineData("bomb")]
+		[InlineData("link")]
+		[InlineData("junk")]
+		public async Task A_hostile_archive_is_refused(string how)
+		{
+			var erin = await _host.Mastodon("erin");
+			var actorJson = new JsonObject { ["id"] = "https://elsewhere.example/users/erin" }.ToJsonString();
+			var zip = how switch
+			{
+				"escape" => Zip(("actor.json", actorJson), ("../escape.txt", "x")),
+				"twice" => Zip(("actor.json", actorJson), ("outbox.json", "{}"), ("outbox.json", "{}")),
+				"bomb" => Zip(("actor.json", actorJson), ("outbox.json", new string(' ', 30 * 1024 * 1024))),
+				"link" => Link(actorJson),
+				_ => "not a zip at all"u8.ToArray()
+			};
+
+			var (status, _) = await Imported(erin.Persona, zip, "posts");
+
+			Assert.Equal(HttpStatusCode.UnprocessableEntity, status);
+			Assert.False(await DB.Default.Find<PostEntity>().Match(p => p.GroupUserId == erin.Persona.Id).ExecuteAnyAsync(Token));
+		}
+
+		// a symbolic link, as zip on Unix stores one
+		static byte[] Link(string actorJson)
+		{
+			var stream = new MemoryStream();
+			using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, leaveOpen: true))
+			{
+				using (var actor = archive.CreateEntry("actor.json").Open())
+					actor.Write(Encoding.UTF8.GetBytes(actorJson));
+				var link = archive.CreateEntry("media_attachments/files/passwd");
+				link.ExternalAttributes = unchecked((int)(0xA1FFu << 16));
+				using var target = link.Open();
+				target.Write("/etc/passwd"u8);
+			}
+			return stream.ToArray();
+		}
+
+		[Fact]
+		public async Task An_outbox_item_too_large_stops_the_import()
+		{
+			var frank = await _host.Mastodon("frank");
+			const string actor = "https://elsewhere.example/users/frank";
+			// (random, so it is no compression bomb: that is refused before the import starts)
+			var words = Convert.ToBase64String(System.Security.Cryptography.RandomNumberGenerator.GetBytes(1536 * 1024));
+			var huge = Create(actor, "1", words, ["https://www.w3.org/ns/activitystreams#Public"], [], "2024-01-01T00:00:00Z");
+			var zip = Zip(("actor.json", new JsonObject { ["id"] = actor }.ToJsonString()),
+				("outbox.json", new JsonObject { ["orderedItems"] = new JsonArray(huge) }.ToJsonString()));
+
+			var (_, state) = await Imported(frank.Persona, zip, "posts");
+
+			Assert.Equal("failed", state["importState"]!.GetValue<string>());
+			Assert.Contains("larger than", state["importError"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task Only_the_personas_own_root_and_never_a_banned_one()
+		{
+			var grace = await _host.Mastodon("grace");
+			var stranger = await _host.SignUp("stranger");
+			using (var other = _host.As(stranger.Jwt))
+				Assert.Equal(HttpStatusCode.NotFound, (await other.GetAsync(Base(grace.Persona), Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.OK, (await _host.As(grace.Persona.Root.Jwt).GetAsync(Base(grace.Persona), Token)).StatusCode);
+			await DB.Default.Update<RootUser>().MatchID(grace.Persona.Root.Id).Modify(u => u.IsBanned, true).ExecuteAsync(Token);
+			Assert.NotEqual(HttpStatusCode.OK, (await _host.As(grace.Persona.Root.Jwt).GetAsync(Base(grace.Persona), Token)).StatusCode);
+		}
+
+		[Fact]
+		public async Task An_import_asked_to_stop_stops()
+		{
+			var henry = await _host.Mastodon("henry");
+			const string actor = "https://elsewhere.example/users/henry";
+			var zip = Zip(("actor.json", new JsonObject { ["id"] = actor }.ToJsonString()),
+				("outbox.json", new JsonObject { ["orderedItems"] = new JsonArray(Create(actor, "1", "one", ["https://www.w3.org/ns/activitystreams#Public"], [], "2024-01-01T00:00:00Z")) }.ToJsonString()));
+			using var client = _host.As(henry.Persona.Root.Jwt);
+			var upload = (await (await client.PostAsync("/clientapi/persona/archive/uploads", null, Token)).Content.ReadFromJsonAsync<JsonObject>(Token))!["id"]!.GetValue<string>();
+			await client.PutAsync($"/clientapi/persona/archive/uploads/{upload}?offset=0", new ByteArrayContent(zip), Token);
+			Assert.Equal(HttpStatusCode.Accepted, (await client.PostAsJsonAsync(Base(henry.Persona) + "/import", new { uploadId = upload, parts = new[] { "posts" } }, Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.Conflict, (await client.PostAsJsonAsync(Base(henry.Persona) + "/import", new { uploadId = upload, parts = new[] { "posts" } }, Token)).StatusCode);
+			Assert.Equal(HttpStatusCode.OK, (await client.PostAsync(Base(henry.Persona) + "/import/stop", null, Token)).StatusCode);
+
+			await _host.Run(j => j.Kind == JobKind.ImportArchive && j.Payload == henry.Persona.Id, Token);
+
+			Assert.Equal("stopped", (await Status(henry.Persona))["importState"]!.GetValue<string>());
+			Assert.False(await DB.Default.Find<PostEntity>().Match(p => p.GroupUserId == henry.Persona.Id).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Http/PersonaExchangeTests.cs

@@ -0,0 +1,218 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.IdentityModel.JsonWebTokens;
+using Microsoft.IdentityModel.Tokens;
+
+using PrivaPub.Api.Mastodon.Auth;
+using PrivaPub.Services;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Security.Claims;
+using System.Text;
+
+namespace PrivaPub.Tests.Http
+{
+	// The first-party client's one sign-in: the /clientapi JWT exchanged for one persona's Mastodon token (PersonaExchange).
+	[Trait("Category", "Integration")]
+	public sealed class PersonaExchangeTests : IAsyncLifetime
+	{
+		const string Grant = "urn:ietf:params:oauth:grant-type:token-exchange";
+		const string FirstParty = "decepub";
+
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		async Task<HttpResponseMessage> Exchange(string jwt, string avatarId, string clientId = FirstParty, string clientSecret = default,
+			string subjectTokenType = PersonaExchange.SubjectTokenType)
+		{
+			var fields = new List<(string, string)>
+			{
+				("grant_type", Grant),
+				("client_id", clientId),
+				("subject_token", jwt),
+				("subject_token_type", subjectTokenType),
+				(PersonaExchange.AvatarParameter, avatarId),
+				("scope", "read write follow")
+			};
+			if (clientSecret != default)
+				fields.Add(("client_secret", clientSecret));
+			using var client = _host.Client();
+			return await client.Form("/oauth/token", fields.Where(f => f.Item2 != default).ToArray());
+		}
+
+		async Task<string> Token(Persona persona)
+		{
+			var response = await Exchange(persona.Root.Jwt, persona.Id);
+			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+			return (await response.JsonBody())["access_token"]!.GetValue<string>();
+		}
+
+		static async Task AssertRefused(HttpResponseMessage response, string error = "invalid_grant")
+		{
+			Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+			Assert.Equal(error, (await response.JsonBody())["error"]?.GetValue<string>());
+		}
+
+		async Task<HttpStatusCode> Me(string token)
+		{
+			using var api = _host.As(token);
+			return (await api.GetAsync("/api/v1/accounts/verify_credentials", TestContext.Current.CancellationToken)).StatusCode;
+		}
+
+		static string Jwt(string rootId, string key, DateTime expires) => new JsonWebTokenHandler().CreateToken(new SecurityTokenDescriptor
+		{
+			Issuer = PrivaPubHost.Base,
+			Audience = PrivaPubHost.Base,
+			Subject = new ClaimsIdentity(new[] { new Claim(ClaimTypes.UserData, rootId) }),
+			NotBefore = expires.AddHours(-2),
+			IssuedAt = expires.AddHours(-2),
+			Expires = expires,
+			SigningCredentials = new(new SymmetricSecurityKey(Encoding.UTF8.GetBytes(key)), SecurityAlgorithms.HmacSha512)
+		});
+
+		[Fact]
+		public async Task The_root_jwt_becomes_one_personas_token_that_never_names_the_root()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "exchange");
+			var root = persona.Root;
+
+			var response = await Exchange(root.Jwt, persona.Id);
+			var body = await response.Content.ReadAsStringAsync(TestContext.Current.CancellationToken);
+
+			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+			Assert.DoesNotContain(root.Id, body);
+			Assert.DoesNotContain(root.UserName, body);
+			var token = (await response.JsonBody())["access_token"]!.GetValue<string>();
+			using var api = _host.As(token);
+			var account = await api.GetStringAsync("/api/v1/accounts/verify_credentials", TestContext.Current.CancellationToken);
+			Assert.Contains($"\"id\":\"{persona.Id}\"", account);
+			Assert.DoesNotContain(root.Id, account);
+			foreach (var entry in await ClientApi.StoredTokens(FirstParty))
+			{
+				var payload = entry.Contains("payload") && entry["payload"].IsString ? ClientApi.JwtPayload(entry["payload"].AsString) : string.Empty;
+				Assert.DoesNotContain(root.Id, entry.ToString() + payload);
+				Assert.DoesNotContain(root.UserName, entry.ToString() + payload);
+			}
+		}
+
+		[Fact]
+		public async Task Each_persona_of_the_root_gets_its_own_token()
+		{
+			var root = await _host.SignUp();
+			var first = await _host.Persona(root, "first");
+			var second = await _host.Persona(root, "second");
+
+			using var firstApi = _host.As(await Token(first));
+			using var secondApi = _host.As(await Token(second));
+
+			Assert.Contains($"\"id\":\"{first.Id}\"", await firstApi.GetStringAsync("/api/v1/accounts/verify_credentials", TestContext.Current.CancellationToken));
+			Assert.Contains($"\"id\":\"{second.Id}\"", await secondApi.GetStringAsync("/api/v1/accounts/verify_credentials", TestContext.Current.CancellationToken));
+		}
+
+		[Fact]
+		public async Task Another_roots_persona_is_refused()
+		{
+			var mine = await _host.SignUp();
+			var theirs = await _host.Persona(await _host.SignUp(), "theirs");
+
+			await AssertRefused(await Exchange(mine.Jwt, theirs.Id));
+			await AssertRefused(await Exchange(mine.Jwt, "000000000000000000000000"));
+			await AssertRefused(await Exchange(mine.Jwt, "not an id"));
+		}
+
+		[Fact]
+		public async Task A_token_that_is_not_a_valid_root_jwt_is_refused()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "forged");
+			var key = _host.Services.GetRequiredService<IConfiguration>()["AppConfiguration:Jwt:Key"]!;
+
+			await AssertRefused(await Exchange("garbage", persona.Id));
+			await AssertRefused(await Exchange(Jwt(persona.Root.Id, key, DateTime.UtcNow.AddMinutes(-10)), persona.Id));
+			await AssertRefused(await Exchange(Jwt(persona.Root.Id, new string('k', 64), DateTime.UtcNow.AddHours(1)), persona.Id));
+		}
+
+		[Fact]
+		public async Task Ended_sessions_refuse_the_jwt_and_revoke_the_exchanged_tokens()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "ended");
+			var token = await Token(persona);
+			Assert.Equal(HttpStatusCode.OK, await Me(token));
+
+			using (var scope = _host.Services.CreateScope())
+				await scope.ServiceProvider.GetRequiredService<IRootSessions>().Revoke(persona.Root.Id, TestContext.Current.CancellationToken);
+
+			await AssertRefused(await Exchange(persona.Root.Jwt, persona.Id));
+			Assert.Equal(HttpStatusCode.Unauthorized, await Me(token));
+		}
+
+		[Fact]
+		public async Task A_banned_root_is_refused()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "banned");
+			await ClientApi.Ban(persona.Root.Id);
+			try
+			{
+				await AssertRefused(await Exchange(persona.Root.Jwt, persona.Id));
+			}
+			finally
+			{
+				await ClientApi.Ban(persona.Root.Id, banned: false);
+			}
+		}
+
+		[Fact]
+		public async Task A_revoked_token_no_longer_works()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "revoked");
+			var token = await Token(persona);
+
+			using var client = _host.Client();
+			var revoked = await client.Form("/oauth/revoke", ("token", token), ("client_id", FirstParty));
+
+			Assert.Equal(HttpStatusCode.OK, revoked.StatusCode);
+			Assert.Equal(HttpStatusCode.Unauthorized, await Me(token));
+		}
+
+		[Fact]
+		public async Task Only_the_first_party_client_may_exchange()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "thirdparty");
+			using var client = _host.Client();
+			var app = await client.RegisterApp();
+
+			var response = await Exchange(persona.Root.Jwt, persona.Id, app.ClientId, app.ClientSecret);
+
+			Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+			Assert.Equal("unauthorized_client", (await response.JsonBody())["error"]?.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task A_mastodon_token_is_not_a_subject_token()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "mastodon");
+			var token = await Token(persona);
+
+			await AssertRefused(await Exchange(token, persona.Id, subjectTokenType: "urn:ietf:params:oauth:token-type:access_token"), "invalid_request");
+			await AssertRefused(await Exchange(token, persona.Id));
+		}
+
+		[Fact]
+		public async Task Missing_parameters_are_a_client_error()
+		{
+			var persona = await _host.Persona(await _host.SignUp(), "missing");
+
+			await AssertRefused(await Exchange(persona.Root.Jwt, default));
+			await AssertRefused(await Exchange(default, persona.Id), "invalid_request");
+			await AssertRefused(await Exchange(persona.Root.Jwt, persona.Id, subjectTokenType: default), "invalid_request");
+		}
+	}
+}

PrivaPub.Tests/Http/PostPlaceTests.cs

@@ -0,0 +1,106 @@
+using MongoDB.Entities;
+
+using PrivaPub.Models.Post;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// A Pixelfed post's own place: stored from `location`, shown as `privapub.place`, changed by an edit.
+	[Trait("Category", "Integration")]
+	public sealed class PostPlaceTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+		Peer _peer;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+			_peer = await Peer.Start();
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		static JsonObject Location(string name, string latitude, string longitude) => new()
+		{
+			["type"] = "Place", ["name"] = name, ["latitude"] = latitude, ["longitude"] = longitude, ["country"] = "Italy"
+		};
+
+		[Fact]
+		public async Task A_pixelfed_place_is_shown_and_follows_the_authors_edits()
+		{
+			var alice = await _host.Mastodon("alice");
+			var ann = new RemoteActor(_peer, "ann");
+			var post = await _host.PublicPostFrom(ann, alice, "<p>the duomo</p>", note => note["location"] = Location("Milan", "45.4642", "9.19"));
+
+			var place = (await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body["privapub"]!["place"];
+
+			Assert.Equal(("Milan", "Italy"), (place.Text("name"), place.Text("country")));
+			Assert.Equal(45.4642, place["latitude"]!.GetValue<double>());
+			Assert.Equal(9.19, place["longitude"]!.GetValue<double>());
+
+			await Edit(ann, alice, post, note => note["location"] = Location("Turin", "45.0703", "7.6869"));
+			Assert.Equal("Turin", (await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body["privapub"]!["place"].Text("name"));
+
+			await Edit(ann, alice, post, _ => { });
+			Assert.Null((await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body["privapub"]!["place"]);
+			Assert.Null((await DB.Default.Find<Post>().MatchID(post.ID).ExecuteFirstAsync(Token)).Place);
+		}
+
+		[Fact]
+		public async Task A_post_without_a_place_has_none()
+		{
+			var alice = await _host.Mastodon("alice");
+			var post = await _host.PublicPostFrom(new RemoteActor(_peer, "plain"), alice);
+
+			Assert.Null((await alice.Client.Get($"/api/v1/statuses/{post.ID}")).Ok().Body["privapub"]!["place"]);
+		}
+
+		[Fact]
+		public async Task A_local_post_never_carries_a_location()
+		{
+			var alice = await _host.Mastodon("alice");
+			var status = await alice.Status("made here");
+
+			using var client = _host.Client();
+			client.DefaultRequestHeaders.Accept.ParseAdd("application/activity+json");
+			var note = JsonNode.Parse(await client.GetStringAsync(status.Text("uri"), Token))!;
+
+			Assert.Null(note["location"]);
+		}
+
+		async Task Edit(RemoteActor author, Mastodon mentioned, Post post, Action<JsonObject> shape)
+		{
+			var note = new JsonObject
+			{
+				["id"] = post.ObjectURI,
+				["type"] = "Note",
+				["attributedTo"] = author.Id,
+				["to"] = new JsonArray(MastodonHelpers.Public),
+				["cc"] = new JsonArray(mentioned.Uri),
+				["content"] = "<p>the duomo, again</p>",
+				["published"] = post.CreationDate.ToString("O"),
+				["updated"] = DateTime.UtcNow.ToString("O"),
+				["tag"] = new JsonArray(new JsonObject { ["type"] = "Mention", ["href"] = mentioned.Uri, ["name"] = "@" + mentioned.UserName })
+			};
+			shape(note);
+			await _host.Deliver(author, mentioned.Mouth, new JsonObject
+			{
+				["id"] = $"{post.ObjectURI}/updates/{Guid.NewGuid():N}",
+				["type"] = "Update",
+				["actor"] = author.Id,
+				["to"] = new JsonArray(MastodonHelpers.Public),
+				["object"] = note
+			});
+		}
+	}
+}

PrivaPub.Tests/Http/ThreadCollectionsTests.cs

@@ -0,0 +1,63 @@
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.Net;
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Http
+{
+	// a public thread names its replies and its conversation (owner decision 2026-10-06), and they list only what is public
+	// or unlisted; a followers-only post names neither
+	[Trait("Category", "Integration")]
+	public sealed class ThreadCollectionsTests : IAsyncLifetime
+	{
+		PrivaPubHost _host;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_host = await PrivaPubHost.Shared();
+		}
+
+		public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+
+		static string PathOf(JsonObject status) => new Uri(status.Text("uri")).AbsolutePath;
+
+		static string[] Items(JsonNode collection) => collection["orderedItems"]!.AsArray().Select(i => i!.GetValue<string>()).ToArray();
+
+		[Fact]
+		public async Task A_public_post_names_its_replies_and_context_which_list_only_public_answers()
+		{
+			var alice = await _host.Mastodon("alice");
+			var carol = await _host.Mastodon("carol");
+			var root = await alice.Status("a public question");
+			var answer = await carol.Status("a public answer", ("in_reply_to_id", root.Text("id")));
+			var hidden = await carol.Status("for my followers", ("in_reply_to_id", root.Text("id")), ("visibility", "private"));
+			var deeper = await alice.Status("and a deeper one", ("in_reply_to_id", answer.Text("id")), ("visibility", "unlisted"));
+
+			var note = (await _host.ActivityPub(PathOf(root))).Ok().Object;
+			Assert.Equal(root.Text("uri") + "/replies", note.Text("replies"));
+			Assert.Equal(root.Text("uri") + "/context", note.Text("context"));
+			var answerNote = (await _host.ActivityPub(PathOf(deeper))).Ok().Object;
+			Assert.Equal(root.Text("uri") + "/context", answerNote.Text("context"));
+
+			var replies = (await _host.ActivityPub(PathOf(root) + "/replies")).Ok().Object;
+			Assert.Equal(new[] { answer.Text("uri") }, Items(replies));
+
+			var context = (await _host.ActivityPub(PathOf(root) + "/context")).Ok().Object;
+			Assert.Equal(new[] { root.Text("uri"), answer.Text("uri"), deeper.Text("uri") }, Items(context));
+			Assert.Equal(alice.Uri, context.Text("attributedTo"));
+			Assert.DoesNotContain(hidden.Text("uri"), Items(context));
+		}
+
+		[Fact]
+		public async Task A_followers_only_post_names_neither_and_serves_neither()
+		{
+			var alice = await _host.Mastodon("alice");
+			var quiet = await alice.Status("for my followers", ("visibility", "private"));
+
+			Assert.Equal(HttpStatusCode.NotFound, (await _host.ActivityPub(PathOf(quiet) + "/replies")).Status);
+			Assert.Equal(HttpStatusCode.NotFound, (await _host.ActivityPub(PathOf(quiet) + "/context")).Status);
+		}
+	}
+}

PrivaPub.Tests/Http/WellKnownTests.cs

@@ -38,6 +38,31 @@ namespace PrivaPub.Tests.Http
 		static string Link(JsonObject document, string rel) =>
 			document["links"]!.AsArray().Single(l => l!["rel"]!.GetValue<string>() == rel)!["href"]!.GetValue<string>();
 
+		// FEP-d556, FEP-2677 and FEP-844e: the server's own actor is found from its origin and from NodeInfo, and says what
+		// the server reads that its documents do not show
+		[Fact]
+		public async Task The_server_actor_is_found_from_the_origin_and_nodeinfo_and_tells_what_it_implements()
+		{
+			var instance = $"{Base}/peasants/privapub";
+			foreach (var resource in new[] { Base, Base + "/" })
+			{
+				var found = await WebFinger(resource);
+				Assert.Equal(HttpStatusCode.OK, found.Status);
+				Assert.Equal(resource, found.Json["subject"]!.GetValue<string>());
+				Assert.Equal(instance, Link(found.Json, "https://www.w3.org/ns/activitystreams#Service"));
+			}
+			var nodeinfo = await _client.Fetch("/.well-known/nodeinfo", "application/json");
+			Assert.Equal(instance, Link(nodeinfo.Json, "https://www.w3.org/ns/activitystreams#Application"));
+
+			var actor = (await _client.Fetch("/peasants/privapub")).Json;
+			Assert.Contains(actor["implements"]!.AsArray(), i => i!["href"]!.GetValue<string>() == "https://datatracker.ietf.org/doc/html/rfc9421");
+			var persona = await _host.Persona(await _host.SignUp(), "generated");
+			var personaActor = (await _client.Fetch($"/peasants/{persona.UserName}")).Json;
+			Assert.Equal("Application", personaActor["generator"]!["type"]!.GetValue<string>());
+			Assert.Contains(personaActor["generator"]!["implements"]!.AsArray(), i => i!["href"]!.GetValue<string>() == "https://datatracker.ietf.org/doc/html/rfc9421");
+			Assert.StartsWith("z6Mk", personaActor["assertionMethod"]![0]!["publicKeyMultibase"]!.GetValue<string>());
+		}
+
 		[Fact]
 		public async Task WebFinger_finds_a_persona_by_acct_and_by_actor_uri()
 		{
@@ -83,7 +108,7 @@ namespace PrivaPub.Tests.Http
 		}
 
 		[Fact]
-		public async Task WebFinger_finds_the_instance_actor_and_a_community()
+		public async Task WebFinger_finds_the_servers_own_actors_and_a_community()
 		{
 			var owner = await _host.Persona(await _host.SignUp(), "fingerowner");
 			var community = await _host.FederatedGroup(owner, community: true);
@@ -95,6 +120,10 @@ namespace PrivaPub.Tests.Http
 			Assert.Equal($"acct:privapub@{Domain}", instance.Json["subject"]!.GetValue<string>());
 			Assert.Equal($"{Base}/peasants/privapub", Link(instance.Json, "self"));
 			Assert.Single(instance.Json["links"]!.AsArray());
+			var reporter = await WebFinger($"acct:privapub_reports@{Domain}");
+			Assert.Equal(HttpStatusCode.OK, reporter.Status);
+			Assert.Equal($"{Base}/peasants/privapub_reports", Link(reporter.Json, "self"));
+			Assert.Single(reporter.Json["links"]!.AsArray());
 			Assert.Equal(HttpStatusCode.OK, group.Status);
 			Assert.Equal($"acct:{community.UserName}@{Domain}", group.Json["subject"]!.GetValue<string>());
 			Assert.Equal(community.Uri, Link(group.Json, "self"));
@@ -179,8 +208,10 @@ namespace PrivaPub.Tests.Http
 			return (await client.Fetch("/nodeinfo/2.1", "application/json")).Json["usage"]!["localPosts"]!.GetValue<long>();
 		}
 
+		// localPosts is Mastodon's: the sum of statuses_count, every local post but DMs and deleted ones, boosts included,
+		// and circle and located posts too (owner decision 2026-10-04)
 		[Fact]
-		public async Task Local_posts_count_only_what_anyone_may_see()
+		public async Task Local_posts_count_as_mastodon_counts_statuses()
 		{
 			var persona = await _host.Persona(await _host.SignUp(), "usage");
 			var friend = await _host.Persona(await _host.SignUp(), "usagefriend");
@@ -197,10 +228,10 @@ namespace PrivaPub.Tests.Http
 			await _host.Reblog(friend, shown);
 			var circle = await _host.FederatedGroup(persona, community: false);
 			await _host.Publish(persona, new StatusDraft { Text = "circle only", PlainText = true, GroupId = circle.Id });
-			Assert.Equal(start + 2, await LocalPosts());
+			Assert.Equal(start + 6, await LocalPosts());//followers-only, located, the boost and the circle post; not the DM nor the copy
 
 			await _host.Remove(persona, shown);
-			Assert.Equal(start + 1, await LocalPosts());
+			Assert.Equal(start + 4, await LocalPosts());//the post and the boost of it
 		}
 	}
 }

PrivaPub.Tests/Infrastructure/BackupTests.cs

@@ -0,0 +1,287 @@
+using MongoDB.Bson;
+using MongoDB.Bson.IO;
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Backup;
+using PrivaPub.Infrastructure.Cli;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+using System.IO.Compression;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	// The server's backup: every collection as it was, byte for byte, read at one instant on a replica set, without what
+	// belongs to the moment (the statistics salt above all), with the media rows' files linked, checkable and rotated.
+	// Each test backs up a database of its own; alone, since the maintenance lock is the server's one.
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class BackupTests : IAsyncLifetime
+	{
+		readonly string _scratch = Path.Combine(Path.GetTempPath(), $"privapub-backup-tests-{Guid.NewGuid():N}");
+		IMongoDatabase _database;
+
+		string Backups => Path.Combine(_scratch, "backups");
+		string Media => Path.Combine(_scratch, "media");
+		string Trash => Path.Combine(_scratch, "media-trash");
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			await PrivaPubHost.Shared();
+			_database = DB.Default.Database().Client.GetDatabase($"PrivaPubBackup_{Guid.NewGuid():N}");
+			Directory.CreateDirectory(Media);
+			Directory.CreateDirectory(Trash);
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_database != default)
+				await _database.Client.DropDatabaseAsync(_database.DatabaseNamespace.DatabaseName);
+			if (Directory.Exists(_scratch))
+				Directory.Delete(_scratch, recursive: true);
+		}
+
+		BackupContext Context(BackupOptions options = default) => new(_database, Backups, Media, Trash, "https://privapub.test", options ?? new BackupOptions());
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		static List<BsonDocument> Read(string file)
+		{
+			using var gzip = new GZipStream(File.OpenRead(file), CompressionMode.Decompress);
+			using var reader = new StreamReader(gzip);
+			var documents = new List<BsonDocument>();
+			while (reader.ReadLine() is { } line)
+				documents.Add(BsonDocument.Parse(line));
+			return documents;
+		}
+
+		async Task<List<byte[]>> Raw(string collection) =>
+			(await (await _database.GetCollection<RawBsonDocument>(collection).FindAsync(FilterDefinition<RawBsonDocument>.Empty, cancellationToken: Token)).ToListAsync(Token))
+				.Select(d =>
+				{
+					var bytes = new byte[d.Slice.Length];
+					d.Slice.GetBytes(0, bytes, 0, bytes.Length);
+					return bytes;
+				})
+				.ToList();
+
+		[Fact]
+		public async Task Every_document_comes_back_byte_for_byte_and_the_salt_never_leaves()
+		{
+			var odd = new BsonDocument
+			{
+				{ "_id", ObjectId.GenerateNewId() },
+				{ "Guid", new BsonBinaryData(Guid.NewGuid(), GuidRepresentation.Standard) },
+				{ "OldGuid", new BsonBinaryData(new byte[16], BsonBinarySubType.UuidLegacy) },
+				{ "Money", new BsonDecimal128(Decimal128.Parse("12345.678900")) },
+				{ "Long", new BsonInt64(long.MaxValue) },
+				{ "Int", 7 },
+				{ "Double", -0.0 },
+				{ "NaN", double.NaN },
+				{ "At", new BsonDateTime(new DateTime(2026, 10, 7, 3, 30, 0, 123, DateTimeKind.Utc)) },
+				{ "Stamp", new BsonTimestamp(1, 2) },
+				{ "Null", BsonNull.Value },
+				{ "Regex", new BsonRegularExpression("^a.b$", "i") },
+				{ "Nested", new BsonDocument { { "z", 1 }, { "a", new BsonArray { 1, "two", new BsonDocument("three", 3) } } } },
+				{ "Unicode", "città 🌍 \u0000 end" }
+			};
+			// an ObjectRecord as big as a remote's long post gets
+			var big = new BsonDocument { { "_id", ObjectId.GenerateNewId() }, { "Json", new string('x', 10 * 1024 * 1024) } };
+			await _database.GetCollection<BsonDocument>("Odd").InsertOneAsync(odd, cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("ObjectRecord").InsertOneAsync(big, cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("Odd").Indexes.CreateOneAsync(
+				new CreateIndexModel<BsonDocument>(Builders<BsonDocument>.IndexKeys.Ascending("At"), new CreateIndexOptions { Name = "at", Unique = true }), cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("InteractionSalt").InsertOneAsync(new BsonDocument("Salt", "never in a backup"), cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("Job").InsertOneAsync(new BsonDocument("Kind", "Deliver"), cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("_migration_history_").InsertManyAsync([
+				new BsonDocument { { "Number", 15 }, { "Name", "older" } }, new BsonDocument { { "Number", 16 }, { "Name", "focal points are finite" } }], cancellationToken: Token);
+
+			var (backup, error) = await ServerBackup.Create(Context(), "manual", dbOnly: false, Token);
+
+			Assert.Null(error);
+			var directory = Path.Combine(Backups, backup.Id);
+			Assert.False(Directory.Exists(directory + ServerBackup.PartialSuffix));
+			Assert.Equal(await Raw("Odd"), Read(Path.Combine(directory, "db", "Odd.jsonl.gz")).Select(d => d.ToBson()).ToList());
+			Assert.Equal(await Raw("ObjectRecord"), Read(Path.Combine(directory, "db", "ObjectRecord.jsonl.gz")).Select(d => d.ToBson()).ToList());
+
+			Assert.False(File.Exists(Path.Combine(directory, "db", "InteractionSalt.jsonl.gz")));
+			Assert.False(File.Exists(Path.Combine(directory, "db", "Job.jsonl.gz")));
+			foreach (var file in Directory.EnumerateFiles(directory, "*", SearchOption.AllDirectories))
+				Assert.DoesNotContain("never in a backup", await ReadAll(file));
+			Assert.Contains(backup.Manifest.Excluded, e => e.Name == "InteractionSalt");
+
+			var odds = backup.Manifest.Collections.Single(c => c.Name == "Odd");
+			Assert.Equal(1, odds.Count);
+			Assert.Contains(odds.Indexes, i => BsonDocument.Parse(i)["name"] == "at" && BsonDocument.Parse(i)["unique"].ToBoolean());
+			Assert.Equal((16, "focal points are finite"), (backup.Manifest.MigrationNumber, backup.Manifest.NewestMigration));
+			Assert.Equal("https://privapub.test", backup.Manifest.Host);
+			Assert.Equal(MongoFixture.Connection.Contains("directConnection=true"), backup.Manifest.Consistent);
+			Assert.Empty(await ServerBackup.Verify(Backups, backup.Id, Token));
+			if (!OperatingSystem.IsWindows())
+			{
+				Assert.Equal(UnixFileMode.UserRead | UnixFileMode.UserWrite | UnixFileMode.GroupRead, File.GetUnixFileMode(Path.Combine(directory, "db", "Odd.jsonl.gz")));
+				Assert.False(File.GetUnixFileMode(directory).HasFlag(UnixFileMode.OtherRead));
+			}
+		}
+
+		static async Task<string> ReadAll(string file)
+		{
+			if (!file.EndsWith(".gz", StringComparison.Ordinal))
+				return await File.ReadAllTextAsync(file, Token);
+			await using var gzip = new GZipStream(File.OpenRead(file), CompressionMode.Decompress);
+			using var reader = new StreamReader(gzip);
+			return await reader.ReadToEndAsync(Token);
+		}
+
+		[Fact]
+		public async Task Media_rows_files_are_linked_from_the_live_directory_or_the_trash()
+		{
+			Directory.CreateDirectory(Path.Combine(Media, "2026", "10"));
+			await File.WriteAllTextAsync(Path.Combine(Media, "2026", "10", "live.jpg"), "live", Token);
+			await File.WriteAllTextAsync(Path.Combine(Media, "2026", "10", "live-preview.jpg"), "preview", Token);
+			Directory.CreateDirectory(Path.Combine(Trash, "2026", "10"));
+			await File.WriteAllTextAsync(Path.Combine(Trash, "2026", "10", "moving.jpg"), "moving", Token);
+			await File.WriteAllTextAsync(Path.Combine(Media, "2026", "10", "trashed.jpg"), "trashed", Token);
+			await _database.GetCollection<BsonDocument>("MediaAttachment").InsertManyAsync([
+				new BsonDocument { { "FilePath", "2026/10/live.jpg" }, { "PreviewPath", "2026/10/live-preview.jpg" }, { "TrashedAt", BsonNull.Value } },
+				new BsonDocument { { "FilePath", "2026/10/moving.jpg" } },//a file the janitor moved while its row was being trashed
+				new BsonDocument { { "FilePath", "2026/10/gone.jpg" } },
+				new BsonDocument { { "FilePath", "2026/10/trashed.jpg" }, { "TrashedAt", DateTime.UtcNow } },
+				new BsonDocument { { "FilePath", "../../etc/passwd" } }], cancellationToken: Token);
+
+			var (backup, _) = await ServerBackup.Create(Context(), "manual", dbOnly: false, Token);
+
+			var media = Path.Combine(Backups, backup.Id, "media");
+			Assert.Equal("live", await File.ReadAllTextAsync(Path.Combine(media, "2026", "10", "live.jpg"), Token));
+			Assert.Equal("preview", await File.ReadAllTextAsync(Path.Combine(media, "2026", "10", "live-preview.jpg"), Token));
+			Assert.Equal("moving", await File.ReadAllTextAsync(Path.Combine(media, "2026", "10", "moving.jpg"), Token));
+			Assert.False(File.Exists(Path.Combine(media, "2026", "10", "trashed.jpg")));
+			Assert.Equal(["2026/10/live-preview.jpg", "2026/10/live.jpg", "2026/10/moving.jpg"], backup.Manifest.Media.List);
+			Assert.Equal((3, 1), (backup.Manifest.Media.Files, backup.Manifest.Media.Missing));
+
+			// a link, not a copy: the live file deleted, the backup's stays
+			File.Delete(Path.Combine(Media, "2026", "10", "live.jpg"));
+			Assert.Equal("live", await File.ReadAllTextAsync(Path.Combine(media, "2026", "10", "live.jpg"), Token));
+
+			// db-only lists them and links none
+			var (listed, _) = await ServerBackup.Create(Context(), "pre-deploy", dbOnly: true, Token);
+			Assert.False(Directory.Exists(Path.Combine(Backups, listed.Id, "media")));
+			Assert.Equal(["2026/10/live-preview.jpg", "2026/10/moving.jpg"], listed.Manifest.Media.List);
+			Assert.Empty(await ServerBackup.Verify(Backups, listed.Id, Token));
+			Assert.Empty(await ServerBackup.Verify(Backups, backup.Id, Token));
+		}
+
+		[Fact]
+		public async Task Verify_finds_an_altered_or_missing_file()
+		{
+			await _database.GetCollection<BsonDocument>("Post").InsertOneAsync(new BsonDocument("Content", "hello"), cancellationToken: Token);
+			await _database.GetCollection<BsonDocument>("Avatar").InsertOneAsync(new BsonDocument("UserName", "someone"), cancellationToken: Token);
+			var (backup, _) = await ServerBackup.Create(Context(), "manual", dbOnly: false, Token);
+			var db = Path.Combine(Backups, backup.Id, "db");
+
+			await File.AppendAllTextAsync(Path.Combine(db, "Post.jsonl.gz"), "tampered", Token);
+			File.Delete(Path.Combine(db, "Avatar.jsonl.gz"));
+
+			Assert.Equal(["Avatar: missing", "Post: altered"], (await ServerBackup.Verify(Backups, backup.Id, Token)).Order());
+			Assert.Equal(["no such backup, or no manifest"], await ServerBackup.Verify(Backups, "../" + backup.Id, Token));
+		}
+
+		[Fact]
+		public async Task One_backup_at_a_time()
+		{
+			await using (var held = await MaintenanceLock.Take("restore", Token))
+			{
+				Assert.NotNull(held);
+				var (backup, error) = await ServerBackup.Create(Context(), "manual", dbOnly: true, Token);
+				Assert.Null(backup);
+				Assert.Contains("already running", error);
+				Assert.Equal("restore", (await MaintenanceLock.Current(Token)).What);
+			}
+			Assert.Null(await MaintenanceLock.Current(Token));
+			Assert.NotNull((await ServerBackup.Create(Context(), "manual", dbOnly: true, Token)).Backup);
+		}
+
+		[Fact]
+		public async Task A_holder_that_died_is_taken_over()
+		{
+			await using var dead = await MaintenanceLock.Take("backup", Token);
+			await DB.Default.Update<MaintenanceLock>().Match(l => l.ID == MaintenanceLock.Name)
+				.Modify(l => l.Heartbeat, DateTime.UtcNow.AddMinutes(-3)).ExecuteAsync(Token);
+
+			Assert.Null(await MaintenanceLock.Current(Token));
+			await using var alive = await MaintenanceLock.Take("restore", Token);
+			Assert.NotNull(alive);
+			Assert.Equal("restore", (await MaintenanceLock.Current(Token)).What);
+		}
+
+		// the newest 7 nightly, the newest of each of the 4 weeks before, the newest 3 pre-deploy; manual ones kept
+		[Fact]
+		public void Rotation_keeps_days_weeks_and_the_last_deploys()
+		{
+			var today = new DateTime(2026, 10, 7, 3, 30, 0, DateTimeKind.Utc);
+			for (var day = 0; day < 60; day++)
+				Fake("nightly", today.AddDays(-day));
+			for (var deploy = 0; deploy < 5; deploy++)
+				Fake("pre-deploy", today.AddDays(-deploy).AddHours(5));
+			Fake("manual", today.AddYears(-1));
+			Directory.CreateDirectory(Path.Combine(Backups, "20260901-000000-nightly" + ServerBackup.PartialSuffix));
+			Directory.SetLastWriteTimeUtc(Path.Combine(Backups, "20260901-000000-nightly" + ServerBackup.PartialSuffix), today.AddDays(-30));
+
+			ServerBackup.Retain(Backups, new BackupOptions());
+
+			var kept = ServerBackup.List(Backups);
+			var nightly = kept.Where(b => b.Kind == "nightly").Select(b => b.CreatedAt).ToList();
+			Assert.Equal(11, nightly.Count);
+			Assert.Equal(Enumerable.Range(0, 7).Select(d => today.AddDays(-d)), nightly.Take(7));
+			Assert.Equal(4, nightly.Skip(7).Select(d => System.Globalization.ISOWeek.GetWeekOfYear(d)).Distinct().Count());
+			Assert.Equal(3, kept.Count(b => b.Kind == "pre-deploy"));
+			Assert.Single(kept, b => b.Kind == "manual");
+			Assert.Empty(Directory.EnumerateDirectories(Backups, "*" + ServerBackup.PartialSuffix));
+		}
+
+		void Fake(string kind, DateTime at)
+		{
+			var directory = Path.Combine(Backups, $"{at:yyyyMMdd-HHmmss}-{kind}");
+			Directory.CreateDirectory(Path.Combine(directory, "db"));
+			new ArchiveManifest { Kind = kind, CreatedAt = at }.Write(directory);
+		}
+
+		[Theory]
+		[InlineData("2026-10-07T03:29:00", "2026-10-06T03:31:00", false)]//yesterday's is the last one due
+		[InlineData("2026-10-07T03:31:00", "2026-10-06T03:31:00", true)]
+		[InlineData("2026-10-07T03:31:00", "2026-10-07T03:30:30", false)]
+		[InlineData("2026-10-07T01:00:00", "2026-10-05T03:31:00", true)]//missed last night: at once
+		public void A_nightly_backup_is_due_once_a_night(string now, string last, bool due) =>
+			Assert.Equal(due, BackupScheduler.IsDue(DateTime.Parse(now, null, System.Globalization.DateTimeStyles.AdjustToUniversal),
+				new TimeOnly(3, 30), [DateTime.Parse(last, null, System.Globalization.DateTimeStyles.AdjustToUniversal)]));
+
+		// the deploy's: the server's own database, through the configuration, without media links
+		[Fact]
+		public async Task The_deploy_backs_up_from_the_command_line()
+		{
+			var host = await PrivaPubHost.Shared();
+			var output = new StringWriter();
+
+			Assert.Equal(0, await AdminCommands.Run(["backup", "--kind", "pre-deploy", "--db-only"], host.Services, output: output));
+			var id = output.ToString().Split(':')[0];
+			Assert.EndsWith("-pre-deploy", id);
+			Assert.Equal(2, await AdminCommands.Run(["backup", "--kind", "nightly"], host.Services, output: TextWriter.Null));
+
+			output = new StringWriter();
+			Assert.Equal(0, await AdminCommands.Run(["backups"], host.Services, output: output));
+			Assert.StartsWith(id + "\tpre-deploy", output.ToString());
+			output = new StringWriter();
+			Assert.Equal(0, await AdminCommands.Run(["backup", "verify", id], host.Services, output: output));
+			Assert.Contains("whole", output.ToString());
+
+			var backups = host.Get<Backups>();
+			var manifest = backups.Find(id).Manifest;
+			Assert.Contains(manifest.Collections, c => c.Name == "Avatar");
+			Assert.DoesNotContain(manifest.Collections, c => c.Name is "InteractionSalt" or "Job" or "MaintenanceLock" or "openiddict.tokens" or "AppConfiguration");
+			Assert.Equal(ServerBackup.CodeMigration(), manifest.MigrationNumber);
+			Assert.True(backups.Delete(id));
+		}
+	}
+}

PrivaPub.Tests/Infrastructure/CdnCatalogTests.cs

@@ -0,0 +1,111 @@
+using PrivaPub.Infrastructure.Geo;
+using PrivaPub.Infrastructure.Http;
+using PrivaPub.Models.Jobs;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	public class CdnCatalogTests
+	{
+		static HttpResponseMessage Response(params (string Name, string Value)[] headers)
+		{
+			var response = new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent("{}") };
+			foreach (var (name, value) in headers)
+				response.Headers.TryAddWithoutValidation(name, value);
+			return response;
+		}
+
+		[Theory]
+		[InlineData("cf-ray", "8c1f0e2b4d5a1234-FRA", "cloudflare.com")]
+		[InlineData("server", "cloudflare", "cloudflare.com")]
+		[InlineData("x-amz-cf-id", "abc==", "cloudfront.net")]
+		[InlineData("via", "1.1 5a1b.cloudfront.net (CloudFront)", "cloudfront.net")]
+		[InlineData("x-served-by", "cache-fra-eddf8230045-FRA", "fastly.com")]
+		[InlineData("server", "BunnyCDN-DE1-1078", "bunny.net")]
+		[InlineData("akamai-grn", "0.1234", "akamai.com")]
+		[InlineData("x-azure-ref", "20261004T101010Z-abc", "azure.microsoft.com")]
+		[InlineData("x-vercel-id", "fra1::abc", "vercel.com")]
+		[InlineData("x-iinfo", "1-2-3", "imperva.com")]
+		public void A_cdn_is_recognised_by_its_fingerprint(string header, string value, string domain)
+		{
+			Assert.Equal(domain, CdnCatalog.FromResponse(Response((header, value)))?.Domain);
+		}
+
+		[Fact]
+		public void A_plain_server_has_no_cdn_and_an_unknown_cdn_names_itself()
+		{
+			Assert.Null(CdnCatalog.FromResponse(Response(("server", "nginx"), ("via", "1.1 varnish"))));
+			var named = CdnCatalog.FromResponse(Response(("x-cdn", "EdgeOne")));
+			Assert.Equal(("EdgeOne", null, "edgeone"), (named.Name, named.Domain, named.Key));
+			Assert.Null(CdnCatalog.FromResponse(Response(("x-cdn", "<script>"))));
+		}
+
+		[Fact]
+		public void Only_networks_that_carry_nothing_but_a_cdn_name_it()
+		{
+			Assert.Equal("Cloudflare", CdnCatalog.OfAsn(13335)?.Name);
+			Assert.Equal("Akamai", CdnCatalog.OfAsn(20940)?.Name);
+			Assert.Null(CdnCatalog.OfAsn(16509));//AWS: CloudFront only by its ranges or its headers
+			Assert.Null(CdnCatalog.OfAsn(60068));//DataPacket also rents servers
+		}
+
+		[Fact]
+		public void Every_published_list_format_is_read()
+		{
+			Assert.Equal(new[] { "173.245.48.0/20", "2400:cb00::/32" },
+				CdnCatalog.Parse(CdnListFormat.Lines, "173.245.48.0/20\n# comment\n\n2400:cb00::/32\n").Select(n => n.ToString()));
+			Assert.Equal(new[] { "89.187.188.227/32", "2400:52e0:1500::714:1/128" },
+				CdnCatalog.Parse(CdnListFormat.StringArray, """["89.187.188.227","2400:52e0:1500::714:1"]""").Select(n => n.ToString()));
+			Assert.Equal(new[] { "23.235.32.0/20", "2a04:4e40::/32" },
+				CdnCatalog.Parse(CdnListFormat.AddressesJson, """{"addresses":["23.235.32.0/20"],"ipv6_addresses":["2a04:4e40::/32"]}""").Select(n => n.ToString()));
+			Assert.Equal(new[] { "92.223.124.12/32", "2a03:90c0::/32" },
+				CdnCatalog.Parse(CdnListFormat.AddressesJson, """{"addresses":["92.223.124.12/32"],"addresses_v6":["2a03:90c0::/32"]}""").Select(n => n.ToString()));
+			Assert.Equal(new[] { "199.83.128.0/21", "2a02:e980::/29" },
+				CdnCatalog.Parse(CdnListFormat.ImpervaJson, """{"ipRanges":["199.83.128.0/21"],"ipv6Ranges":["2a02:e980::/29"],"res":0}""").Select(n => n.ToString()));
+			Assert.Equal(new[] { "13.32.0.0/15", "2600:9000::/28" },
+				CdnCatalog.Parse(CdnListFormat.AwsCloudFront, """
+					{"prefixes":[{"ip_prefix":"3.4.12.4/32","service":"AMAZON"},{"ip_prefix":"13.32.0.0/15","service":"CLOUDFRONT"}],
+					 "ipv6_prefixes":[{"ipv6_prefix":"2600:9000::/28","service":"CLOUDFRONT"},{"ipv6_prefix":"2406:daba::/40","service":"EC2"}]}
+					""").Select(n => n.ToString()));
+			Assert.Throws<FormatException>(() => CdnCatalog.Parse(CdnListFormat.Lines, "173.245.48.0/20\nnot an address"));
+		}
+
+		[Fact]
+		public void The_published_ranges_name_the_cdn_of_an_address()
+		{
+			var ranges = new CdnRanges();
+			ranges.Replace(new CdnRangeSet { Key = "cloudflare.com", Name = "Cloudflare", Ranges = new() { "104.16.0.0/13", "2606:4700::/32" }, FetchedAt = DateTime.UtcNow });
+
+			Assert.Equal("Cloudflare", ranges.Of(IPAddress.Parse("104.18.2.3"))?.Name);
+			Assert.Equal("Cloudflare", ranges.Of(IPAddress.Parse("::ffff:104.18.2.3"))?.Name);
+			Assert.Equal("Cloudflare", ranges.Of(IPAddress.Parse("2606:4700::1"))?.Name);
+			Assert.Null(ranges.Of(IPAddress.Parse("203.0.113.7")));
+			Assert.Equal(2, ranges.Status["cloudflare.com"].Ranges);
+		}
+
+		[Fact]
+		public async Task Responses_leave_a_cdn_hint_for_their_host_until_one_comes_without()
+		{
+			var hints = new EdgeHints();
+			var answers = new Queue<HttpResponseMessage>(new[] { Response(("cf-ray", "1-FRA")), Response(("server", "nginx")) });
+			using var client = new HttpClient(new EdgeHintsHandler(hints) { InnerHandler = new Answering(answers) });
+
+			await client.GetAsync("https://social.example/.well-known/nodeinfo", TestContext.Current.CancellationToken);
+			Assert.Equal("Cloudflare", hints.Of("social.example")?.Name);
+
+			await client.GetAsync("https://social.example/nodeinfo/2.1", TestContext.Current.CancellationToken);
+			Assert.Null(hints.Of("social.example"));
+		}
+
+		sealed class Answering : HttpMessageHandler
+		{
+			readonly Queue<HttpResponseMessage> _answers;
+
+			public Answering(Queue<HttpResponseMessage> answers) => _answers = answers;
+
+			protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) =>
+				Task.FromResult(_answers.Dequeue());
+		}
+	}
+}

PrivaPub.Tests/Infrastructure/CdnUpdaterTests.cs

@@ -0,0 +1,105 @@
+using Microsoft.Extensions.Logging.Abstractions;
+
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Geo;
+using PrivaPub.Infrastructure.Statistics;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Tests.Support;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	[Trait("Category", "Integration")]
+	public sealed class CdnUpdaterTests : IAsyncLifetime
+	{
+		Peer _peer;
+		CdnRanges _ranges;
+		CdnUpdater _updater;
+		string _key;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_peer = await Peer.Start();
+			_ranges = new CdnRanges();
+			_updater = new CdnUpdater(new Clients(), new StaticOptions<StatisticsOptions>(new StatisticsOptions()), _ranges, NullLogger<CdnUpdater>.Instance);
+			_key = $"edge{Guid.NewGuid():N}.example";
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		sealed class Clients : IHttpClientFactory
+		{
+			public HttpClient CreateClient(string name) => new();
+		}
+
+		CdnProvider Provider() => new("Test Edge", _key, Array.Empty<int>(), new[]
+		{
+			new CdnList($"{_peer.A}/edge/v4", CdnListFormat.Lines),
+			new CdnList($"{_peer.A}/edge/v6", CdnListFormat.StringArray)
+		}, _ => false);
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		[Fact]
+		public async Task The_published_ranges_are_downloaded_stored_and_used()
+		{
+			_peer.ServeText("/edge/v4", "198.51.100.0/24\n", "text/plain");
+			_peer.ServeText("/edge/v6", """["2001:db8::/32","192.0.2.9"]""", "application/json");
+
+			Assert.Equal(1, await _updater.Update(new[] { Provider() }, Token));
+
+			var stored = await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteSingleAsync(Token);
+			Assert.Equal(new[] { "198.51.100.0/24", "2001:db8::/32", "192.0.2.9/32" }, stored.Ranges);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("198.51.100.20"))?.Name);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("192.0.2.9"))?.Name);
+
+			var restarted = new CdnRanges();
+			await restarted.Load(Token);
+			Assert.Equal("Test Edge", restarted.Of(IPAddress.Parse("2001:db8::7"))?.Name);
+		}
+
+		[Theory]
+		[InlineData("not a network")]
+		[InlineData("")]
+		public async Task A_broken_or_empty_list_keeps_the_stored_ranges(string broken)
+		{
+			_peer.ServeText("/edge/v4", "198.51.100.0/24", "text/plain");
+			_peer.ServeText("/edge/v6", "[]", "application/json");
+			Assert.Equal(1, await _updater.Update(new[] { Provider() }, Token));
+
+			_peer.ServeText("/edge/v4", broken, "text/plain");
+			Assert.Equal(0, await _updater.Update(new[] { Provider() }, Token));
+
+			Assert.Equal(new[] { "198.51.100.0/24" }, (await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteSingleAsync(Token)).Ranges);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("198.51.100.1"))?.Name);
+		}
+
+		// The real lists, from the CDNs themselves: set PRIVAPUB_TEST_CDN_LIVE=1 to check that every format still parses.
+		[Fact]
+		public async Task Every_cdns_real_list_still_parses()
+		{
+			Assert.SkipUnless(Environment.GetEnvironmentVariable("PRIVAPUB_TEST_CDN_LIVE") == "1", "set PRIVAPUB_TEST_CDN_LIVE=1 to download the real lists");
+			var listed = CdnCatalog.All.Where(p => p.Lists.Length > 0).ToList();
+
+			Assert.Equal(listed.Count, await _updater.Update(listed, Token));
+
+			Assert.Equal("Cloudflare", _ranges.Of(IPAddress.Parse("104.16.0.1"))?.Name);
+			foreach (var provider in listed)
+				Assert.True(_ranges.Status[provider.Key].Ranges > 0, provider.Name);
+		}
+
+		[Fact]
+		public async Task An_unreachable_list_changes_nothing()
+		{
+			Assert.Equal(0, await _updater.Update(new[] { Provider() }, Token));
+			Assert.False(await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteAnyAsync(Token));
+		}
+	}
+}

PrivaPub.Tests/Infrastructure/FederationHttpTests.cs

@@ -27,6 +27,12 @@ namespace PrivaPub.Tests.Infrastructure
 			_peer.MapGet("/big", () => Results.Text("{\"a\":\"" + new string('a', FederationHttp.MaxResponseBytes) + "\"}", "application/activity+json"));
 			_peer.MapGet("/hop/{n:int}", (int n) => Results.Redirect(n == 0 ? "/actor" : $"/hop/{n - 1}"));
 			_peer.MapGet("/gone", () => Results.StatusCode(410));
+			// Mobilizon's NodeInfo: a profile URL left unquoted, which .NET cannot parse as a media type
+			_peer.MapGet("/nodeinfo", (HttpContext context) =>
+			{
+				context.Response.Headers.ContentType = "application/json; profile=http://nodeinfo.diaspora.software/ns/schema/2.1#; charset=utf-8";
+				return context.Response.WriteAsync("{\"software\":{\"name\":\"Mobilizon\"}}");
+			});
 			await _peer.StartAsync();
 			_base = _peer.Urls.First();
 		}
@@ -64,6 +70,13 @@ namespace PrivaPub.Tests.Infrastructure
 		public async Task Refuses_a_fourth_redirect() =>
 			Assert.Null(await Client().GetJson($"{_base}/hop/3", "application/activity+json", default, TestContext.Current.CancellationToken));
 
+		[Fact]
+		public async Task Reads_json_under_a_content_type_dotnet_cannot_parse()
+		{
+			using var fetched = await Client().GetJson($"{_base}/nodeinfo", "application/json", default, TestContext.Current.CancellationToken);
+			Assert.Equal("Mobilizon", fetched.Root.GetProperty("software").GetProperty("name").GetString());
+		}
+
 		[Fact]
 		public async Task Refuses_html() =>
 			Assert.Null(await Client().GetJson($"{_base}/html", "application/activity+json", default, TestContext.Current.CancellationToken));

PrivaPub.Tests/Infrastructure/GeoLocatorTests.cs

@@ -1,4 +1,4 @@
-using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Logging.Abstractions;
 
 using PrivaPub.Infrastructure.Geo;
 using PrivaPub.Infrastructure.Http;
@@ -45,7 +45,7 @@ namespace PrivaPub.Tests.Infrastructure
 			Assert.NotNull(fix);
 			Assert.Equal(2, fix.Country.Length);
 			Assert.Equal(13335, fix.Asn);
-			Assert.Equal("Cloudflare", CdnNetworks.Of(fix.Asn));
+			Assert.Equal("Cloudflare", CdnCatalog.OfAsn(fix.Asn)?.Name);
 			Assert.NotNull(fix.AsnOrg);
 			Assert.NotNull(fix.Latitude);
 			Assert.Equal(Math.Round(fix.Latitude.Value, 1), fix.Latitude);
@@ -61,9 +61,9 @@ namespace PrivaPub.Tests.Infrastructure
 
 			Assert.Equal(IPAddress.Parse("203.0.113.7"), connected.Of("social.example"));
 			Assert.Null(connected.Of("other.example"));
-			Assert.Equal("Fastly", CdnNetworks.Of(54113));
+			Assert.Equal("Fastly", CdnCatalog.OfAsn(54113)?.Name);
-			Assert.Null(CdnNetworks.Of(64496));
+			Assert.Null(CdnCatalog.OfAsn(64496));
-			Assert.Null(CdnNetworks.Of(default));
+			Assert.Null(CdnCatalog.OfAsn(default));
 		}
 	}
 }

PrivaPub.Tests/Infrastructure/IndexTests.cs

@@ -59,6 +59,8 @@ namespace PrivaPub.Tests.Infrastructure
 			Assert.True(await local.IsUserNameTaken(name, token));
 			Assert.False(await local.TryReserveUserName("admin", LocalActorKind.Person, "c", token));
 			Assert.False(await local.TryReserveUserName(LocalActorService.InstanceUserName, LocalActorKind.Person, "c", token));
+			Assert.False(await local.TryReserveUserName(LocalActorService.ReporterUserName, LocalActorKind.Group, "c", token));
+			Assert.True(await local.IsUserNameTaken("PrivaPub_Reports", token));
 		}
 	}
 }

PrivaPub.Tests/Infrastructure/JobQueueTests.cs

@@ -1,3 +1,5 @@
+using Microsoft.Extensions.Logging.Abstractions;
+
 using MongoDB.Entities;
 
 using PrivaPub.Infrastructure.Jobs;
@@ -74,6 +76,8 @@ namespace PrivaPub.Tests.Infrastructure
 			Assert.Equal(JobState.Pending, after.State);
 			Assert.True(after.RunAt > DateTime.UtcNow.AddSeconds(10));
 
+			// leased again for its third attempt (a finish only counts for the lease it was given)
+			await DB.Default.Update<Job>().MatchID(leased.ID).Modify(j => j.State, JobState.Running).Modify(j => j.LeaseOwner, leased.LeaseOwner).ExecuteAsync(token);
 			leased.Attempts = 3;
 			await queue.Finish(leased, JobOutcome.Retry("boom"), maxAttempts: 3, token);
 			Assert.Equal(JobState.Dead, (await DB.Default.Find<Job>().OneAsync(leased.ID, token)).State);
@@ -90,5 +94,100 @@ namespace PrivaPub.Tests.Infrastructure
 
 			Assert.Equal(JobState.Pending, (await DB.Default.Find<Job>().OneAsync(job.ID, token)).State);
 		}
+
+		// a handler running three times its lease keeps it: the reaper finds nothing to take back and it runs once
+		[Fact]
+		public async Task A_long_job_keeps_its_lease_and_runs_once()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var kind = (JobKind)(2000 + Random.Shared.Next(100000));
+			var queue = new JobQueue(TimeSpan.FromSeconds(1.5), j => j.Kind == kind);
+			var handler = new SlowHandler(kind, TimeSpan.FromSeconds(4.5));
+			await queue.Enqueue(kind, "{}", default, default, token);
+
+			using var worker = new JobWorker(queue, new IJobHandler[] { handler }, NullLogger<JobWorker>.Instance);
+			await worker.StartAsync(token);
+			try
+			{
+				var deadline = DateTime.UtcNow.AddSeconds(20);
+				while (!await DB.Default.Find<Job>().Match(j => j.Kind == kind && j.State == JobState.Done).ExecuteAnyAsync(token))
+				{
+					Assert.True(DateTime.UtcNow < deadline, "the job never finished");
+					Assert.Equal(0, await queue.Reap(token));
+					await Task.Delay(250, token);
+				}
+			}
+			finally
+			{
+				await worker.StopAsync(CancellationToken.None);
+			}
+
+			Assert.Equal(1, handler.Started);
+		}
+
+		// a lease taken by another worker (reaped, then leased again) stops the handler, and its outcome is not recorded
+		[Fact]
+		public async Task A_lost_lease_stops_the_handler_and_drops_its_outcome()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var kind = (JobKind)(2000 + Random.Shared.Next(100000));
+			var queue = new JobQueue(TimeSpan.FromSeconds(1.5), j => j.Kind == kind);
+			var handler = new SlowHandler(kind, TimeSpan.FromSeconds(30));
+			await queue.Enqueue(kind, "{}", default, default, token);
+
+			using var worker = new JobWorker(queue, new IJobHandler[] { handler }, NullLogger<JobWorker>.Instance);
+			await worker.StartAsync(token);
+			try
+			{
+				var deadline = DateTime.UtcNow.AddSeconds(20);
+				while (handler.Started == 0)
+				{
+					Assert.True(DateTime.UtcNow < deadline, "the job never started");
+					await Task.Delay(100, token);
+				}
+				await DB.Default.Update<Job>().Match(j => j.Kind == kind).Modify(j => j.LeaseOwner, "another worker").ExecuteAsync(token);
+				while (!handler.Cancelled)
+				{
+					Assert.True(DateTime.UtcNow < deadline, "the handler was never stopped");
+					await Task.Delay(100, token);
+				}
+				await Task.Delay(300, token);
+			}
+			finally
+			{
+				await worker.StopAsync(CancellationToken.None);
+			}
+
+			var job = await DB.Default.Find<Job>().Match(j => j.Kind == kind).ExecuteFirstAsync(token);
+			Assert.Equal(JobState.Running, job.State);
+			Assert.Equal("another worker", job.LeaseOwner);
+		}
+
+		sealed class SlowHandler(JobKind kind, TimeSpan takes) : IJobHandler
+		{
+			int _started;
+
+			public int Started => _started;
+			public bool Cancelled { get; private set; }
+			public JobKind Kind => kind;
+			public int Concurrency => 1;
+			public int MaxAttempts => 3;
+			public int PerHostLimit => 1;
+
+			public async Task<JobOutcome> Handle(Job job, CancellationToken token)
+			{
+				Interlocked.Increment(ref _started);
+				try
+				{
+					await Task.Delay(takes, token);
+				}
+				catch (OperationCanceledException)
+				{
+					Cancelled = true;
+					throw;
+				}
+				return JobOutcome.Done;
+			}
+		}
 	}
 }

PrivaPub.Tests/Infrastructure/MigrationTests.cs

@@ -1,3 +1,4 @@
+using PrivaPub.Models.Media;
 using MongoDB.Bson;
 using MongoDB.Driver;
 using MongoDB.Entities;
@@ -22,6 +23,31 @@ namespace PrivaPub.Tests.Infrastructure
 	[Trait("Category", "Integration")]
 	public class MigrationTests
 	{
+		[Fact]
+		public async Task A_focal_point_that_is_not_a_number_is_removed()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			var token = TestContext.Current.CancellationToken;
+			var broken = new MediaAttachment { OwnerAvatarId = "a1", Focus = [float.NaN, 0f] };
+			var sound = new MediaAttachment { OwnerAvatarId = "a1", Focus = [0.5f, -0.5f] };
+			var post = new Post
+			{
+				ObjectURI = $"https://privapub.test/{Guid.NewGuid():N}",
+				Media = [new PostMedia { URL = "https://privapub.test/media/files/a.jpg", Focus = [float.PositiveInfinity, 0f] }, new PostMedia { URL = "https://privapub.test/media/files/b.jpg", Focus = [0.1f, 0.2f] }]
+			};
+			await DB.Default.SaveAsync(broken, token);
+			await DB.Default.SaveAsync(sound, token);
+			await DB.Default.SaveAsync(post, token);
+
+			await new _016_focal_points_are_finite().UpgradeAsync();
+
+			Assert.Null((await DB.Default.Find<MediaAttachment>().OneAsync(broken.ID, token)).Focus);
+			Assert.Equal(new[] { 0.5f, -0.5f }, (await DB.Default.Find<MediaAttachment>().OneAsync(sound.ID, token)).Focus);
+			var migrated = await DB.Default.Find<Post>().OneAsync(post.ID, token);
+			Assert.Null(migrated.Media[0].Focus);
+			Assert.Equal(new[] { 0.1f, 0.2f }, migrated.Media[1].Focus);
+		}
+
 		[Fact]
 		public async Task Stored_remote_content_is_sanitized_and_local_content_rendered()
 		{

PrivaPub.Tests/Infrastructure/RestoreTests.cs

@@ -0,0 +1,316 @@
+using Microsoft.Extensions.Logging.Abstractions;
+
+using MongoDB.Bson;
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Backup;
+using PrivaPub.Infrastructure.Cli;
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	// A backup restored at boot: what was made since is lost, what protects is not (owner decision 2026-10-07). A server
+	// in a database of its own is backed up, changed, and restored; alone, since the maintenance lock is the server's one.
+	[Trait("Category", "Integration")]
+	[Xunit.Collection(nameof(Exclusive))]
+	public sealed class RestoreTests : IAsyncLifetime
+	{
+		const string Host = "https://privapub.test";
+
+		readonly string _scratch = Path.Combine(Path.GetTempPath(), $"privapub-restore-tests-{Guid.NewGuid():N}");
+		IMongoDatabase _database;
+
+		string Backups => Path.Combine(_scratch, "backups");
+		string Media => Path.Combine(_scratch, "media");
+		string Trash => Path.Combine(_scratch, "media-trash");
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			await PrivaPubHost.Shared();
+			_database = DB.Default.Database().Client.GetDatabase($"PrivaPubRestore_{Guid.NewGuid():N}");
+			Directory.CreateDirectory(Media);
+			Directory.CreateDirectory(Trash);
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_database != default)
+				await _database.Client.DropDatabaseAsync(_database.DatabaseNamespace.DatabaseName);
+			if (Directory.Exists(_scratch))
+				Directory.Delete(_scratch, recursive: true);
+		}
+
+		BackupContext Context(string host = Host) => new(_database, Backups, Media, Trash, host, new BackupOptions());
+
+		IMongoCollection<BsonDocument> C(string name) => _database.GetCollection<BsonDocument>(name);
+
+		async Task<BsonDocument> One(string collection, BsonDocument filter) =>
+			await (await C(collection).FindAsync(filter, cancellationToken: Token)).FirstOrDefaultAsync(Token);
+
+		async Task<List<BsonDocument>> All(string collection) =>
+			await (await C(collection).FindAsync(FilterDefinition<BsonDocument>.Empty, cancellationToken: Token)).ToListAsync(Token);
+
+		static BsonDocument Id(ObjectId id) => new("_id", id);
+
+		static Task Set(IMongoCollection<BsonDocument> collection, ObjectId id, BsonDocument fields) =>
+			collection.UpdateOneAsync(Id(id), new BsonDocument("$set", fields), cancellationToken: Token);
+
+		// the ids of the town this test builds
+		readonly ObjectId _alice = ObjectId.GenerateNewId(), _alicePersona = ObjectId.GenerateNewId();
+		readonly ObjectId _deletedPost = ObjectId.GenerateNewId(), _editedPost = ObjectId.GenerateNewId(), _laterPost = ObjectId.GenerateNewId();
+		readonly ObjectId _deletedMedia = ObjectId.GenerateNewId(), _laterMedia = ObjectId.GenerateNewId();
+		readonly ObjectId _bob = ObjectId.GenerateNewId(), _bobPersona = ObjectId.GenerateNewId();
+
+		static string Uri(ObjectId post) => $"{Host}/peasants/alice/posts/{post}";
+
+		async Task<BackupInfo> TownBackedUp()
+		{
+			await File.WriteAllTextAsync(Path.Combine(Media, "deleted.jpg"), "deleted", Token);
+			await C("RootUser").InsertOneAsync(new BsonDocument { { "_id", _alice }, { "UserName", "alice" }, { "HashedPassword", "old" }, { "SessionStamp", "s1" }, { "Policies", new BsonArray { "IsUser" } }, { "DeletedAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("Avatar").InsertOneAsync(new BsonDocument { { "_id", _alicePersona }, { "UserName", "alice" }, { "SuspendedAt", BsonNull.Value }, { "DeletionAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("RootToAvatar").InsertOneAsync(new BsonDocument { { "RootId", _alice.ToString() }, { "AvatarId", _alicePersona.ToString() } }, cancellationToken: Token);
+			await C("ReservedName").InsertOneAsync(new BsonDocument("Name", "alice"), cancellationToken: Token);
+			await C("Post").InsertManyAsync([
+				new BsonDocument { { "_id", _deletedPost }, { "GroupUserId", _alicePersona.ToString() }, { "IsFederatedCopy", false }, { "ObjectURI", Uri(_deletedPost) }, { "Text", "regret" },
+					{ "Media", new BsonArray { new BsonDocument("AttachmentId", _deletedMedia.ToString()) } }, { "DeletedAt", BsonNull.Value } },
+				new BsonDocument { { "_id", _editedPost }, { "GroupUserId", _alicePersona.ToString() }, { "IsFederatedCopy", false }, { "ObjectURI", Uri(_editedPost) }, { "Text", "first words" }, { "DeletedAt", BsonNull.Value } }
+			], cancellationToken: Token);
+			await C("TimelineEntry").InsertOneAsync(new BsonDocument { { "PostId", _deletedPost.ToString() }, { "ReblogOfPostId", BsonNull.Value } }, cancellationToken: Token);
+			await C("MediaAttachment").InsertOneAsync(new BsonDocument { { "_id", _deletedMedia }, { "PostId", _deletedPost.ToString() }, { "FilePath", "deleted.jpg" }, { "TrashedAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("Follower").InsertOneAsync(new BsonDocument { { "LocalActorId", _alicePersona.ToString() }, { "ActorURI", "https://elsewhere.example/users/left" } }, cancellationToken: Token);
+			await C("RemoteInstance").InsertOneAsync(new BsonDocument { { "Host", "down.example" }, { "ConsecutiveFailures", 9 }, { "UnavailableUntil", DateTime.UtcNow.AddDays(1) } }, cancellationToken: Token);
+			await C("_migration_history_").InsertOneAsync(new BsonDocument { { "Number", 16 }, { "Name", "focal points are finite" } }, cancellationToken: Token);
+			await C("InteractionSalt").InsertOneAsync(new BsonDocument("Salt", "the backup's day"), cancellationToken: Token);
+
+			var (backup, error) = await ServerBackup.Create(Context(), "manual", dbOnly: false, Token);
+			Assert.Null(error);
+			return backup;
+		}
+
+		// what happens after the backup: protective acts, and things merely made or changed
+		async Task LifeGoesOn()
+		{
+			// alice regrets a post: deleted, its media trashed and moved out of what is served
+			await Set(C("Post"), _deletedPost, new BsonDocument { { "DeletedAt", DateTime.UtcNow }, { "Text", BsonNull.Value }, { "Media", new BsonArray() } });
+			await Set(C("MediaAttachment"), _deletedMedia, new BsonDocument { { "TrashedAt", DateTime.UtcNow }, { "TrashReason", "deleted" } });
+			File.Move(Path.Combine(Media, "deleted.jpg"), Path.Combine(Trash, "deleted.jpg"));
+			await C("TimelineEntry").DeleteManyAsync(new BsonDocument("PostId", _deletedPost.ToString()), Token);
+			// an edit, a new post with a picture: not protective
+			await Set(C("Post"), _editedPost, new BsonDocument("Text", "second words"));
+			await File.WriteAllTextAsync(Path.Combine(Media, "later.jpg"), "later", Token);
+			await C("Post").InsertOneAsync(new BsonDocument { { "_id", _laterPost }, { "GroupUserId", _alicePersona.ToString() }, { "IsFederatedCopy", false }, { "ObjectURI", Uri(_laterPost) }, { "Text", "later" }, { "DeletedAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("MediaAttachment").InsertOneAsync(new BsonDocument { { "_id", _laterMedia }, { "PostId", _laterPost.ToString() }, { "FilePath", "later.jpg" }, { "TrashedAt", BsonNull.Value } }, cancellationToken: Token);
+			// a follower leaves, another comes
+			await C("Follower").DeleteManyAsync(FilterDefinition<BsonDocument>.Empty, Token);
+			await C("Follower").InsertOneAsync(new BsonDocument { { "LocalActorId", _alicePersona.ToString() }, { "ActorURI", "https://elsewhere.example/users/came" } }, cancellationToken: Token);
+			// alice blocks someone, the admin blocks a server, someone is reported, alice's persona is suspended, she changes
+			// her password
+			await C("Block").InsertOneAsync(new BsonDocument { { "AvatarId", _alicePersona.ToString() }, { "TargetActorURI", "https://elsewhere.example/users/troll" } }, cancellationToken: Token);
+			await C("DomainBlock").InsertOneAsync(new BsonDocument { { "Domain", "evil.example" }, { "Severity", "Suspend" } }, cancellationToken: Token);
+			await C("Report").InsertOneAsync(new BsonDocument("Comment", "harassment"), cancellationToken: Token);
+			await Set(C("Avatar"), _alicePersona, new BsonDocument("SuspendedAt", DateTime.UtcNow));
+			await Set(C("RootUser"), _alice, new BsonDocument("HashedPassword", "new"));
+			// bob arrives
+			await C("RootUser").InsertOneAsync(new BsonDocument { { "_id", _bob }, { "UserName", "bob" }, { "HashedPassword", "bob's" }, { "Policies", new BsonArray { "IsUser" } }, { "DeletedAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("Avatar").InsertOneAsync(new BsonDocument { { "_id", _bobPersona }, { "UserName", "bob" }, { "DeletionAt", BsonNull.Value } }, cancellationToken: Token);
+			await C("RootToAvatar").InsertOneAsync(new BsonDocument { { "RootId", _bob.ToString() }, { "AvatarId", _bobPersona.ToString() } }, cancellationToken: Token);
+			await C("ReservedName").InsertOneAsync(new BsonDocument("Name", "bob"), cancellationToken: Token);
+			// sessions, a list made, today's salt, work queued
+			await C("openiddict.tokens").InsertOneAsync(new BsonDocument("subject", "alice"), cancellationToken: Token);
+			await C("PersonaList").InsertOneAsync(new BsonDocument { { "AvatarId", _alicePersona.ToString() }, { "Title", "friends" } }, cancellationToken: Token);
+			await C("InteractionSalt").DeleteManyAsync(FilterDefinition<BsonDocument>.Empty, Token);
+			await C("InteractionSalt").InsertOneAsync(new BsonDocument("Salt", "today's"), cancellationToken: Token);
+			await C("Job").InsertOneAsync(new BsonDocument("Kind", "Deliver"), cancellationToken: Token);
+		}
+
+		async Task AssertRestoredAndProtected(BackupInfo backup)
+		{
+			// lost: what was merely made or changed since
+			Assert.Equal("first words", (await One("Post", Id(_editedPost)))["Text"].AsString);
+			var later = await One("Post", Id(_laterPost));
+			Assert.False(later["DeletedAt"].IsBsonNull);
+			Assert.True(later["Text"].IsBsonNull);
+			Assert.Empty(await All("PersonaList"));
+			Assert.Equal(16, (await One("_migration_history_", new BsonDocument()))["Number"].ToInt32());
+
+			// kept: every protective act
+			var deleted = await One("Post", Id(_deletedPost));
+			Assert.False(deleted["DeletedAt"].IsBsonNull);
+			Assert.True(deleted["Text"].IsBsonNull);
+			Assert.Null(await One("TimelineEntry", new BsonDocument("PostId", _deletedPost.ToString())));
+			Assert.False((await One("MediaAttachment", Id(_deletedMedia)))["TrashedAt"].IsBsonNull);
+			Assert.Equal("restore: made after the backup", (await One("MediaAttachment", Id(_laterMedia)))["TrashReason"].AsString);
+			Assert.Equal(["https://elsewhere.example/users/came"], (await All("Follower")).Select(f => f["ActorURI"].AsString));
+			Assert.NotNull(await One("Block", new BsonDocument("TargetActorURI", "https://elsewhere.example/users/troll")));
+			Assert.NotNull(await One("DomainBlock", new BsonDocument("Domain", "evil.example")));
+			Assert.NotNull(await One("Report", new BsonDocument("Comment", "harassment")));
+			Assert.False((await One("Avatar", Id(_alicePersona)))["SuspendedAt"].IsBsonNull);
+			var alice = await One("RootUser", Id(_alice));
+			Assert.Equal("new", alice["HashedPassword"].AsString);
+			Assert.NotEqual("s1", alice["SessionStamp"].AsString);
+
+			// bob, made since: deleted, his name kept
+			var bob = await One("RootUser", Id(_bob));
+			Assert.Equal($"deleted-{_bob}", bob["UserName"].AsString);
+			Assert.True(bob["HashedPassword"].IsBsonNull);
+			Assert.False(bob["DeletedAt"].IsBsonNull);
+			Assert.False((await One("Avatar", Id(_bobPersona)))["DeletionAt"].IsBsonNull);
+			Assert.NotNull(await One("ReservedName", new BsonDocument("Name", "bob")));
+
+			// what a backup never holds is as it was; sessions end; circuits close
+			Assert.Equal("today's", (await One("InteractionSalt", new BsonDocument()))["Salt"].AsString);
+			Assert.Single(await All("Job"));
+			Assert.Empty(await All("openiddict.tokens"));
+			Assert.Equal(0, (await One("RemoteInstance", new BsonDocument("Host", "down.example")))["ConsecutiveFailures"].ToInt32());
+
+			// the picture of the deleted post came back from the backup, to be trashed again by the janitor
+			Assert.True(File.Exists(Path.Combine(Media, "deleted.jpg")));
+			Assert.Null(RestoreMarker.Read(Backups));
+			var record = await (await _database.GetCollection<RestoreRecord>(nameof(RestoreRecord)).FindAsync(r => r.Backup == backup.Id, cancellationToken: Token)).FirstAsync(Token);
+			Assert.Equal(["bob"], record.Report.RootsTombstoned);
+			Assert.Equal(["bob"], record.Report.PersonasTombstoned);
+			Assert.Equal(1, record.Report.PostsGone);
+			Assert.Equal(1, record.Report.PostsDeleted);
+		}
+
+		[Fact]
+		public async Task A_restore_loses_what_was_made_since_but_never_a_protective_act()
+		{
+			var backup = await TownBackedUp();
+			await LifeGoesOn();
+
+			Assert.Null(await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+			Assert.Contains("already pending", await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+			Assert.Equal(RestoreOutcome.Restored, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+
+			await AssertRestoredAndProtected(backup);
+			var before = ServerBackup.List(Backups).Single(b => b.Kind == "pre-restore");
+			Assert.Equal(before.Id, (await (await _database.GetCollection<RestoreRecord>(nameof(RestoreRecord)).FindAsync(FilterDefinition<RestoreRecord>.Empty, cancellationToken: Token)).FirstAsync(Token)).PreRestore);
+		}
+
+		// an attempt that died midway: the next one starts again from the backup, with the same pre-restore backup, never
+		// one of the half-restored database
+		[Fact]
+		public async Task A_restore_that_died_midway_converges_on_the_next_boot()
+		{
+			var backup = await TownBackedUp();
+			await LifeGoesOn();
+			Assert.Null(await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+			Assert.Equal(RestoreOutcome.Restored, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+			var before = ServerBackup.List(Backups).Single(b => b.Kind == "pre-restore");
+
+			// as if the boot died after importing a collection, with the marker saying so
+			await C("Post").DeleteManyAsync(FilterDefinition<BsonDocument>.Empty, Token);
+			await C("Block").DeleteManyAsync(FilterDefinition<BsonDocument>.Empty, Token);
+			new RestoreMarker { Backup = backup.Id, PreRestore = before.Id, State = "running", Attempts = 1, RequestedBy = "admin" }.Write(Backups);
+
+			Assert.Equal(RestoreOutcome.Restored, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+			Assert.Single(ServerBackup.List(Backups), b => b.Kind == "pre-restore");
+			await AssertRestoredAndProtected(backup);
+		}
+
+		[Fact]
+		public async Task A_backup_from_elsewhere_from_a_newer_build_or_altered_is_refused()
+		{
+			var backup = await TownBackedUp();
+
+			Assert.Contains("not https://other.test", await ServerRestore.Request(Context("https://other.test"), backup.Id, "admin", Token));
+			Assert.Contains("no such backup", await ServerRestore.Request(Context(), "../" + backup.Id, "admin", Token));
+
+			var manifest = ArchiveManifest.Read(Path.Combine(Backups, backup.Id));
+			manifest.MigrationNumber = ServerBackup.CodeMigration() + 1;
+			manifest.Write(Path.Combine(Backups, backup.Id));
+			Assert.Contains("newer build", await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+
+			manifest.MigrationNumber = 16;
+			manifest.Write(Path.Combine(Backups, backup.Id));
+			await File.AppendAllTextAsync(Path.Combine(Backups, backup.Id, "db", "Post.jsonl.gz"), "x", Token);
+			Assert.Contains("Post: altered", await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+			Assert.Null(RestoreMarker.Read(Backups));
+		}
+
+		// refused at boot before anything changed (the backup went meanwhile): recorded, and the server boots as it was
+		[Fact]
+		public async Task A_restore_that_cannot_start_is_abandoned_and_changes_nothing()
+		{
+			var backup = await TownBackedUp();
+			await LifeGoesOn();
+			Assert.Null(await ServerRestore.Request(Context(), backup.Id, "admin", Token));
+			ServerBackup.Delete(Backups, backup.Id);
+
+			Assert.Equal(RestoreOutcome.Abandoned, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+
+			Assert.Equal("second words", (await One("Post", Id(_editedPost)))["Text"].AsString);
+			Assert.Null(RestoreMarker.Read(Backups));
+			Assert.DoesNotContain(ServerBackup.List(Backups), b => b.Kind == "pre-restore");
+			var record = await (await _database.GetCollection<RestoreRecord>(nameof(RestoreRecord)).FindAsync(FilterDefinition<RestoreRecord>.Empty, cancellationToken: Token)).FirstAsync(Token);
+			Assert.True(record.Abandoned);
+			Assert.Contains("no such backup", record.Error);
+		}
+
+		[Fact]
+		public async Task After_three_failures_it_waits_for_someone_to_look()
+		{
+			var backup = await TownBackedUp();
+			await LifeGoesOn();
+			new RestoreMarker { Backup = backup.Id, PreRestore = "gone", State = "running", Attempts = RestoreMarker.MaxAttempts, Error = "disk full" }.Write(Backups);
+
+			Assert.Equal(RestoreOutcome.GaveUp, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+			Assert.Equal("second words", (await One("Post", Id(_editedPost)))["Text"].AsString);
+			Assert.NotNull(RestoreMarker.Read(Backups));
+
+			await File.WriteAllTextAsync(RestoreMarker.PathIn(Backups), "{ not json", Token);
+			Assert.Equal(RestoreOutcome.GaveUp, await ServerRestore.ApplyPending(Context(), NullLogger.Instance, Token));
+		}
+
+		// a command waits while a restore does; asking how it goes doesn't
+		[Fact]
+		public async Task Commands_wait_for_a_restore_asked_for()
+		{
+			var host = await PrivaPubHost.Shared();
+			var backups = host.Get<Backups>();
+			new RestoreMarker { Backup = "20260101-000000-manual", RequestedBy = "cli" }.Write(backups.Root);
+			try
+			{
+				Assert.Equal(MaintenanceGate.TryLater, await MaintenanceGate.Enter(host.Services, ["promote", "someone"], Token));
+				Assert.Null(await MaintenanceGate.Enter(host.Services, ["restore", "--status"], Token));
+				var output = new StringWriter();
+				Assert.Equal(0, await AdminCommands.Run(["restore", "--status"], host.Services, output: output));
+				Assert.Contains("waiting: 20260101-000000-manual, pending", output.ToString());
+				Assert.Equal(1, await AdminCommands.Run(["restore", "20260101-000000-manual"], host.Services, output: TextWriter.Null));
+			}
+			finally
+			{
+				RestoreMarker.Clear(backups.Root);
+			}
+		}
+
+		// FEP-8fcf: for two weeks after a restore, no digests, and no follow undone for them
+		[Fact]
+		public async Task Followers_digests_rest_for_two_weeks_after_a_restore()
+		{
+			RestoreRecord.Forget();
+			Assert.False(await RestoreRecord.InFollowersGrace(Token));
+			var record = new RestoreRecord { Backup = "test", RestoredAt = DateTime.UtcNow.AddDays(-13) };
+			await DB.Default.SaveAsync(record, Token);
+			try
+			{
+				RestoreRecord.Forget();
+				Assert.True(await RestoreRecord.InFollowersGrace(Token));
+				await DB.Default.Update<RestoreRecord>().MatchID(record.ID).Modify(r => r.RestoredAt, DateTime.UtcNow.AddDays(-15)).ExecuteAsync(Token);
+				RestoreRecord.Forget();
+				Assert.False(await RestoreRecord.InFollowersGrace(Token));
+			}
+			finally
+			{
+				await DB.Default.DeleteAsync<RestoreRecord>(record.ID);
+				RestoreRecord.Forget();
+			}
+		}
+	}
+}

PrivaPub.Tests/Infrastructure/TopologyTests.cs

@@ -0,0 +1,21 @@
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Data;
+using PrivaPub.Tests.Support;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	[Trait("Category", "Integration")]
+	public sealed class TopologyTests
+	{
+		// tools/ci/with-test-mongod.sh starts a one-member replica set, as production's mongod is: the backup's snapshot reads
+		// are what the tests exercise
+		[Fact]
+		public async Task The_test_mongod_is_a_replica_set_like_productions()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			Assert.SkipUnless(MongoFixture.Connection.Contains("directConnection=true"), "a mongod not started by tools/ci/with-test-mongod.sh");
+			Assert.True(await MongoTopology.IsReplicaSet(DB.Default.Database(), TestContext.Current.CancellationToken));
+		}
+	}
+}

PrivaPub.Tests/Statistics/DescribeTests.cs

@@ -1,4 +1,4 @@
-using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Logging.Abstractions;
 
 using MongoDB.Entities;
 
@@ -44,6 +44,23 @@ namespace PrivaPub.Tests.Statistics
 			Assert.Equal(7, facts.LocalComments);
 			Assert.Equal(new[] { "en", "de" }, facts.Languages);
 			Assert.Null(InstanceDocuments.NodeInfo(Json("{}"), "2.0").UsersTotal);
+			// NodeInfo wants the name in lower case, which Mobilizon does not keep
+			Assert.Equal("mobilizon", InstanceDocuments.NodeInfo(Json("""{"software":{"name":"Mobilizon"}}"""), "2.1").Software);
+		}
+
+		// Castopod publishes NodeInfo2 only
+		[Fact]
+		public void NodeInfo2_gives_the_server_and_its_usage()
+		{
+			var facts = InstanceDocuments.NodeInfo2(Json("""
+				{"version":"1.0","server":{"baseUrl":"https://castopod.test/","name":"Castopod","software":"Castopod","version":"1.15.5"},
+				 "protocols":["activitypub"],"openRegistrations":false,"usage":{"users":{"total":1,"activeMonth":1,"activeHalfyear":1},"localPosts":3}}
+				"""));
+
+			Assert.Equal(("castopod", "1.15.5", "Castopod", "nodeinfo2-1.0"), (facts.Software, facts.SoftwareVersion, facts.NodeName, facts.Version));
+			Assert.Equal(new[] { "activitypub" }, facts.Protocols);
+			Assert.Equal((1L, 3L), (facts.UsersTotal.Value, facts.LocalPosts.Value));
+			Assert.Null(InstanceDocuments.NodeInfo2(Json("""{"version":"1.0","server":{}}""")));
 		}
 
 		[Fact]
@@ -57,6 +74,10 @@ namespace PrivaPub.Tests.Statistics
 
 			Assert.Equal(("https://a.example/2.2", "2.2"), InstanceDocuments.NodeInfoLink(links));
 			Assert.Equal(default, InstanceDocuments.NodeInfoLink(Json("[]")));
+			// Funkwhale 2.0 links its NodeInfo under its swagger schema's URL
+			Assert.Equal(("https://f.example/api/v2/instance/nodeinfo/2.1", "2.1"), InstanceDocuments.NodeInfoLink(Json("""
+				{"links":[{"rel":"https://docs.funkwhale.audio/swagger/schema.yml","href":"https://f.example/api/v2/instance/nodeinfo/2.1"}]}
+				""")));
 		}
 
 		[Fact]
@@ -78,16 +99,16 @@ namespace PrivaPub.Tests.Statistics
 		}
 
 		[Fact]
-		public void The_public_location_depends_on_size_and_on_a_cdn()
+		public void The_public_location_is_where_the_server_was_located_unless_a_cdn_hides_it()
 		{
 			var geo = new InstanceGeo { Country = "DE", City = "Berlin", Latitude = 52.5, Longitude = 13.4, AsnOrg = "Hetzner", Asn = 24940 };
 
-			Assert.Equal(new PublicLocation("DE", "Berlin", 52.5, 13.4, "Hetzner", null), PublicGeo.Project(new RemoteInstance { Geo = geo, UsersTotal = 10 }, 10));
+			Assert.Equal(new PublicLocation("DE", "Berlin", 52.5, 13.4, "Hetzner", null), PublicGeo.Project(geo));
-			Assert.Equal(new PublicLocation("DE", null, null, null, null, null), PublicGeo.Project(new RemoteInstance { Geo = geo, UsersTotal = 1 }, 10));
+			Assert.Equal(new PublicLocation("DE", null, null, null, null, null), PublicGeo.Project(new InstanceGeo { Country = "DE" }));
-			Assert.Equal(new PublicLocation("DE", null, null, null, null, null), PublicGeo.Project(new RemoteInstance { Geo = geo }, 10));
 			Assert.Equal(new PublicLocation(null, null, null, null, null, "Cloudflare"),
-				PublicGeo.Project(new RemoteInstance { Geo = new InstanceGeo { Country = "US", City = "SF", Cdn = "Cloudflare" }, UsersTotal = 5000 }, 10));
+				PublicGeo.Project(new InstanceGeo { Country = "US", City = "SF", Latitude = 37.8, Longitude = -122.4, Cdn = "Cloudflare" }));
-			Assert.Null(PublicGeo.Project(new RemoteInstance(), 10));
+			Assert.Null(PublicGeo.Project(new InstanceGeo()));
+			Assert.Null(PublicGeo.Project(null));
 		}
 	}
 
@@ -112,7 +133,8 @@ namespace PrivaPub.Tests.Statistics
 		{
 			readonly string _peer;
 
-			public PeerDescriber(IFederationHttp http, IGeoLocator geo, IConnectedAddresses addresses, string peer) : base(http, geo, addresses) => _peer = peer;
+			public PeerDescriber(IFederationHttp http, IGeoLocator geo, IConnectedAddresses addresses, string peer, ICdnRanges ranges = default,
+				IEdgeHints edges = default) : base(http, geo, addresses, ranges, edges) => _peer = peer;
 
 			protected override string Address(string url) => _peer + new Uri(url).PathAndQuery;
 		}
@@ -155,6 +177,31 @@ namespace PrivaPub.Tests.Statistics
 			Assert.Equal(InstanceDescriber.Week(DateTime.UtcNow), snapshot.Week);
 		}
 
+		[Fact]
+		public async Task A_cdn_is_found_by_its_published_ranges_first_then_by_its_headers()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var listed = $"listed{Guid.NewGuid():N}.example";
+			var hinted = $"hinted{Guid.NewGuid():N}.example";
+			ServeServer("/" + listed, "mastodon");
+			ServeServer("/" + hinted, "mastodon");
+			var addresses = new ConnectedAddresses();
+			var ranges = new CdnRanges();
+			ranges.Replace(new CdnRangeSet { Key = "cloudflare.com", Name = "Cloudflare", Ranges = new() { "127.0.0.0/8" }, FetchedAt = DateTime.UtcNow });
+			var edges = new EdgeHints();
+			edges.Remember("127.0.0.1", CdnCatalog.ByKey("fastly.com"));
+
+			await new PeerDescriber(Peer.Http(connected: addresses), new FixedGeo(), addresses, _peer.A + "/" + listed, ranges, edges).Describe(listed, crawled: false, default, token);
+			await new PeerDescriber(Peer.Http(connected: addresses), new FixedGeo(), addresses, _peer.A + "/" + hinted, new CdnRanges(), edges).Describe(hinted, crawled: false, default, token);
+
+			var listedOne = await DB.Default.Find<RemoteInstance>().Match(i => i.Host == listed).ExecuteSingleAsync(token);
+			Assert.Equal(("Cloudflare", "cloudflare.com", "ranges"), (listedOne.Geo.Cdn, listedOne.Geo.CdnDomain, listedOne.Geo.CdnSource));
+			var hintedOne = await DB.Default.Find<RemoteInstance>().Match(i => i.Host == hinted).ExecuteSingleAsync(token);
+			Assert.Equal(("Fastly", "fastly.com", "headers"), (hintedOne.Geo.Cdn, hintedOne.Geo.CdnDomain, hintedOne.Geo.CdnSource));
+			var snapshot = await DB.Default.Find<RemoteInstanceSnapshot>().Match(s => s.Host == listed).ExecuteSingleAsync(token);
+			Assert.Equal(("Cloudflare", "cloudflare.com", "ranges", "Amsterdam", 52.4), (snapshot.Cdn, snapshot.CdnDomain, snapshot.CdnSource, snapshot.City, snapshot.Latitude!.Value));
+		}
+
 		[Fact]
 		public async Task Without_api_v2_the_v1_api_is_read_and_an_unreachable_week_is_recorded_too()
 		{
@@ -174,6 +221,30 @@ namespace PrivaPub.Tests.Statistics
 			Assert.False((await DB.Default.Find<RemoteInstanceSnapshot>().Match(s => s.Host == gone).ExecuteSingleAsync(token)).Reachable);
 		}
 
+		// a server whose NodeInfo failed is asked again on its next arrival, not a week later
+		[Fact]
+		public async Task A_failed_description_frees_its_weeks_key_and_a_good_one_keeps_it()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var broken = $"broken{Guid.NewGuid():N}.example";
+			var fine = $"fine{Guid.NewGuid():N}.example";
+			ServeServer("/" + fine, "smithereen", v2: false);
+			var queue = new JobQueue();
+			async Task Run(string host)
+			{
+				var key = InstanceDescriber.DedupeKey(host, DateTime.UtcNow);
+				Assert.True(await queue.Enqueue(JobKind.DescribeInstance, host, host, key, token));
+				var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == key).ExecuteSingleAsync(token);
+				await new PeerDescriber(Peer.Http(), default, default, _peer.A + "/" + host).Handle(job, token);
+			}
+
+			await Run(broken);
+			await Run(fine);
+
+			Assert.True(await queue.Enqueue(JobKind.DescribeInstance, broken, broken, InstanceDescriber.DedupeKey(broken, DateTime.UtcNow), token));
+			Assert.False(await queue.Enqueue(JobKind.DescribeInstance, fine, fine, InstanceDescriber.DedupeKey(fine, DateTime.UtcNow), token));
+		}
+
 		[Fact]
 		public async Task A_crawled_server_never_downgrades_a_touched_one_and_robots_are_obeyed()
 		{

PrivaPub.Tests/Statistics/InteractionsTests.cs

@@ -49,6 +49,8 @@ namespace PrivaPub.Tests.Statistics
 			Assert.Equal("-", Interactions.Host("evil host/with path"));
 			Assert.Equal("-", Interactions.Host(default));
 			Assert.Equal("social.example", Interactions.HostOf("https://Social.Example:8443/users/x"));
+			// RFC 9421's algorithm names carry an underscore
+			Assert.Equal("rfc9421:rsa-v1_5-sha256", Interactions.Sanitize(new InteractionEvent { Signature = "rfc9421:rsa-v1_5-sha256" }).Signature);
 		}
 
 		[Fact]

PrivaPub.Tests/Support/Harness.cs

@@ -14,6 +14,7 @@ using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Inbox;
 using PrivaPub.Federation.Inbox.Handlers;
 using PrivaPub.Federation.Outbox;
+using PrivaPub.Federation.Relays;
 using PrivaPub.Infrastructure.Jobs;
 using PrivaPub.Models;
 using PrivaPub.Federation.Objects;
@@ -43,41 +44,56 @@ namespace PrivaPub.Tests.Support
 			Local = new LocalActorService(Db, new StaticOptions<AppConfiguration>(new AppConfiguration { BackendBaseAddress = Base }));
 			Remote = new RemoteActorService(Peer.Http(cache), Local, cache, Db);
 			Delivery = new DeliveryService(Db, Queue);
+			Relays = new Relays(Microsoft.Extensions.Options.Options.Create(RelayOptions), Remote, Local, Delivery);
 			Fanout = new Fanout(Db);
 			Groups = new GroupDistributor(Delivery);
 			Records = new ObjectRecords(Queue);
 			Polls = new PollService(Db, Local, Delivery, Queue);
 			Reactions = new Reactions(Db, Delivery);
 			RemotePosts = new RemotePosts(Db, Local, Remote, new NoBlocks(), Queue, Records, new NoPreviews());
-			Outbox = new OutboxPublisher(Db, Local, Delivery);
+			Outbox = new OutboxPublisher(Db, Local, Delivery, Relays);
 			Quotes = new QuoteService(Db, Remote, RemotePosts, Local, Delivery, Outbox);
+			Approvals = new InteractionApprovals(Db, Remote, Local, Delivery, Outbox);
+			Participations = new Participations(Db, Local, Delivery);
 			Receiver = new InboxReceiver(Local, Remote, Queue, new NoBlocks(), NullLogger<InboxReceiver>.Instance, Ledger);
+			Follows = new FollowService(Db, Local, Remote, Delivery, new KeyLocalizer<GenericRes>(), NullLogger<FollowService>.Instance);
+			Relationships = new RelationshipService(Db, Follows, Delivery);
+			Featured = new FeaturedPosts(Db, Remote, RemotePosts);
+			Walls = new Walls(Db, Local, RemotePosts, Delivery, Fanout);
 			Handlers = new IActivityHandler[]
 			{
 				new FollowHandler(Db, Local, Remote, Delivery),
-				new AcceptHandler(Db, Local, Quotes),
+				new AcceptHandler(Db, Local, Quotes, Approvals, Participations, Relays, Queue),
-				new RejectHandler(Db, Local, Quotes),
+				new RejectHandler(Db, Local, Quotes, Approvals, Participations, Relays),
+				new ReplyApprovalHandler(Approvals),
+				new ReplyRejectionHandler(Approvals),
 				new UndoHandler(Db, Local, Reactions),
 				new LikeHandler(Db, Reactions),
 				new EmojiReactHandler(Db, Reactions),
 				new QuoteRequestHandler(Quotes),
+				new WarnHandler(Db, Local, Remote),
+				new ResolveHandler(Db, Local),
 				new DislikeHandler(Db),
 				new JoinHandler(Db, Local, Delivery),
-				new AnnounceHandler(Db, Local, RemotePosts, Fanout, Remote, Records, Quotes),
+				new AnnounceHandler(Db, Local, RemotePosts, Fanout, Remote, Records, Quotes, relays: Relays),
-				new CreateHandler(Db, Local, Remote, Delivery, new NoBlocks(), Fanout, RemotePosts, Groups, Records, Polls, new NoPreviews(), Quotes),
+				new CreateHandler(Db, Local, Remote, Delivery, new NoBlocks(), Fanout, RemotePosts, Groups, Records, Polls, new NoPreviews(), Quotes, Approvals, Relays, Walls),
 				new DeleteHandler(Db, Local, Remote, Delivery, Groups, Quotes),
-				new UpdateHandler(Db, Local, Remote, Groups, Records, Quotes),
+				new UpdateHandler(Db, Local, Remote, Groups, Records, Quotes, Delivery),
-				new FlagHandler(Db, Local)
+				new FlagHandler(Db, Local),
+				new BlockHandler(Db, Local),
+				new LockHandler(Db),
+				new MoveHandler(Remote, Db, Local, Follows, Relationships),
+				new FeaturedHandler(Featured, add: true, Walls, Remote, Queue),
+				new FeaturedHandler(Featured, add: false, Walls, Remote, Queue)
 			};
-			Processor = new InboxProcessor(Remote, Handlers, NullLogger<InboxProcessor>.Instance, Ledger);
+			((AnnounceHandler)Handlers.First(h => h is AnnounceHandler)).Relays = Handlers;
-			Follows = new FollowService(Db, Local, Remote, Delivery, new KeyLocalizer<GenericRes>(), NullLogger<FollowService>.Instance);
+			Processor = new InboxProcessor(Remote, Handlers, NullLogger<InboxProcessor>.Instance, Ledger, Local);
 			Content = new ContentRenderer(Local, Remote);
 			Media = new MediaService(new StaticOptions<MediaOptions>(new MediaOptions { Root = Path.Combine(Path.GetTempPath(), $"privapub-media-{Guid.NewGuid():N}") }),
 				Local, default, NullLogger<MediaService>.Instance);
-			Statuses = new StatusService(Db, Local, Remote, Delivery, Content, Outbox, Fanout, Media, Groups, Polls, new NoPreviews(), Quotes);
+			Statuses = new StatusService(Db, Local, Remote, Delivery, Content, Outbox, Fanout, Media, Groups, Polls, new NoPreviews(), Quotes, Approvals);
 			Posts = new PostsService(Db, Local, Statuses, new KeyLocalizer<GenericRes>(), NullLogger<PostsService>.Instance);
 			Timelines = new TimelineService(Db, new KeyLocalizer<GenericRes>());
-			Relationships = new RelationshipService(Db, Follows, Delivery);
 			Reports = new ReportService(Db, Local, Delivery);
 		}
 
@@ -104,8 +120,15 @@ namespace PrivaPub.Tests.Support
 		public PollService Polls { get; }
 		public Reactions Reactions { get; }
 		public QuoteService Quotes { get; }
+		public InteractionApprovals Approvals { get; }
+		public Participations Participations { get; }
 		public TimelineService Timelines { get; }
 		public RelationshipService Relationships { get; }
+		public FeaturedPosts Featured { get; }
+		public Walls Walls { get; }
+		public Relays Relays { get; }
+		// the relays the harness's instance actor subscribes to: a test sets them before Relays.Reconcile
+		public PrivaPub.Infrastructure.Http.FederationOptions RelayOptions { get; } = new();
 		public ReportService Reports { get; }
 
 		public async Task FollowedBy(LocalActor local, RemoteActor follower) =>
@@ -133,9 +156,12 @@ namespace PrivaPub.Tests.Support
 		public async Task<InboxResult> Deliver(RemoteActor sender, string path, JsonNode activity)
 		{
 			var result = await Receiver.Receive(sender.Post(Host, path, activity), default, CancellationToken.None);
-			var dedupe = "inbox|" + (activity is JsonObject ? activity["id"]?.GetValue<string>() : default);
+			// the job this delivery queued: under its id, or apart (a forwarded copy; an id its sender reused)
-			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == dedupe).ExecuteFirstAsync();
+			var id = activity is JsonObject ? activity["id"]?.GetValue<string>() : default;
-			if (job != default)
+			var dedupe = (result.Reason == "forwarded" ? "inbox|forwarded|" : "inbox|") + id;
+			var job = await DB.Default.Find<Job>().Match(j => (j.DedupeKey == dedupe || j.DedupeKey.StartsWith(dedupe + "|")) && j.State == JobState.Pending)
+				.Sort(j => j.CreatedAt, Order.Descending).ExecuteFirstAsync();
+			if (job != default && result.Reason != "duplicate")
 				Assert.Equal(JobResult.Done, (await Processor.Handle(job, CancellationToken.None)).Result);
 			return result;
 		}

PrivaPub.Tests/Support/Host/PrivaPubHost.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
@@ -23,7 +23,9 @@ namespace PrivaPub.Tests.Support.Host
 		public const string ClientHeader = "X-Test-Client";
 
 		static readonly SemaphoreSlim Boot = new(1, 1);
-		static readonly Type[] Unwanted = { typeof(JobWorker), typeof(MediaJanitor), typeof(OAuthPruner), typeof(StatisticsSchedule) };
+		static readonly Type[] Unwanted = { typeof(JobWorker), typeof(MediaJanitor), typeof(OAuthPruner), typeof(StatisticsSchedule),
+			typeof(PrivaPub.Domain.Social.FollowResender), typeof(PrivaPub.Infrastructure.Backup.BackupScheduler),
+			typeof(PrivaPub.Infrastructure.Backup.RestoreWatcher) };
 		static PrivaPubHost _shared;
 
 		readonly string _mediaRoot = Path.Combine(Path.GetTempPath(), $"privapub-tests-{Guid.NewGuid():N}");
@@ -75,7 +77,12 @@ namespace PrivaPub.Tests.Support.Host
 			["Federation:FetchLinkPreviews"] = "false",
 			["Registrations:Mode"] = "Open",
 			["Statistics:Geo:AutoUpdate"] = "false",
+			["Statistics:Cdn:AutoUpdate"] = "false",
 			["Media:Root"] = _mediaRoot,
+			["Backups:Root"] = _mediaRoot + "-backups",
+			["Backups:Nightly"] = "false",
+			["RateLimits:UploadsBurst"] = "1000",
+			["RateLimits:ProxyBurst"] = "100000",
 			["Logging:LogLevel:Default"] = "Warning",
 			["Serilog:MinimumLevel:Default"] = Environment.GetEnvironmentVariable("PRIVAPUB_TEST_LOGS") == "1" ? "Information" : "Fatal"
 		};
@@ -113,8 +120,11 @@ namespace PrivaPub.Tests.Support.Host
 		protected override void Dispose(bool disposing)
 		{
 			base.Dispose(disposing);
-			if (disposing && Directory.Exists(_mediaRoot))
+			if (!disposing)
-				Directory.Delete(_mediaRoot, recursive: true);
+				return;
+			foreach (var directory in new[] { _mediaRoot, _mediaRoot + "-backups", _mediaRoot + "-trash", _mediaRoot + "-incoming", _mediaRoot + "-proxy" })
+				if (Directory.Exists(directory))
+					Directory.Delete(directory, recursive: true);
 		}
 
 		sealed class ClientAddressFilter : IStartupFilter

PrivaPub.Tests/Support/Peer.cs

@@ -21,6 +21,7 @@ namespace PrivaPub.Tests.Support
 		readonly ConcurrentDictionary<string, (string Text, string ContentType)> _documents = new();
 		readonly ConcurrentDictionary<string, (int Status, TimeSpan Delay)> _answers = new();
 		readonly ConcurrentDictionary<string, (byte[] Bytes, string ContentType)> _files = new();
+		readonly ConcurrentDictionary<string, string> _etags = new();
 
 		public int Port { get; }
 		public string A => $"http://127.0.0.1:{Port}";
@@ -64,6 +65,15 @@ namespace PrivaPub.Tests.Support
 					context.Response.StatusCode = StatusCodes.Status404NotFound;
 					return;
 				}
+				if (peer._etags.TryGetValue(key, out var etag))
+				{
+					if (context.Request.Headers.IfNoneMatch.ToString() == etag)
+					{
+						context.Response.StatusCode = StatusCodes.Status304NotModified;
+						return;
+					}
+					context.Response.Headers.ETag = etag;
+				}
 				context.Response.ContentType = document.ContentType;
 				await context.Response.WriteAsync(document.Text.Replace("{A}", peer.A).Replace("{B}", peer.B));
 			});
@@ -74,6 +84,13 @@ namespace PrivaPub.Tests.Support
 
 		public void Serve(string path, string json) => _documents[path] = (json, "application/activity+json");
 
+		// a document with an ETag: answered 304 to a request that names it in If-None-Match
+		public void ServeTagged(string path, string json, string etag)
+		{
+			_documents[path] = (json, "application/activity+json");
+			_etags[path] = etag;
+		}
+
 		public void ServeText(string path, string text, string contentType) => _documents[path] = (text, contentType);
 
 		public void ServeFile(string path, byte[] bytes, string contentType) => _files[path] = (bytes, contentType);

PrivaPub.Tests/Support/RemoteActor.cs

@@ -13,12 +13,22 @@ namespace PrivaPub.Tests.Support
 	public sealed class RemoteActor
 	{
 		readonly RSA _key = RSA.Create(2048);
+		readonly bool _namesSharedInbox;
+		readonly bool _hasWall;
+		readonly string _ed25519;
 
-		public RemoteActor(Peer peer, string name, string origin = default, string type = "Person")
+		// sharedInbox: whether its document names its server's shared inbox (endpoints.sharedInbox), as Mastodon's do; wall:
+		// whether it has a wall (sm:wall, Smithereen's); ed25519: whether it has an Ed25519 key (FEP-521a) to prove what it
+		// sends (FEP-8b32)
+		public RemoteActor(Peer peer, string name, string origin = default, string type = "Person", bool sharedInbox = false, bool wall = false,
+			bool ed25519 = false)
 		{
+			_ed25519 = ed25519 ? PrivaPub.Federation.Signing.IntegrityProofs.NewSeed() : default;
 			Name = $"{name}{Guid.NewGuid():N}"[..20];
 			Id = $"{origin ?? peer.A}/users/{Name}";
 			Type = type;
+			_namesSharedInbox = sharedInbox;
+			_hasWall = wall;
 			peer.Serve($"/users/{Name}", Document().ToJsonString());
 		}
 
@@ -28,21 +38,45 @@ namespace PrivaPub.Tests.Support
 		public string Id { get; }
 		public string KeyId => Id + "#main-key";
 		public string SharedInbox => Id.Split("/users/")[0] + "/inbox";
+		public string Wall => Id + "/wall";
 
-		public JsonObject Document() => new()
+		// the activity with its proof by this actor's Ed25519 key
+		public JsonObject Prove(JsonObject activity)
 		{
-			["id"] = Id,
+			activity["proof"] = PrivaPub.Federation.Signing.IntegrityProofs.Create(activity, Id + "#ed25519-key", _ed25519, DateTime.UtcNow);
-			["type"] = Type,
+			return activity;
-			["preferredUsername"] = Name,
+		}
-			["inbox"] = Id + "/inbox",
+
-			["followers"] = Id + "/followers",
+		public JsonObject Document()
-			["publicKey"] = new JsonObject
+		{
+			var document = new JsonObject
 			{
-				["id"] = KeyId,
+				["id"] = Id,
-				["owner"] = Id,
+				["type"] = Type,
-				["publicKeyPem"] = _key.ExportSubjectPublicKeyInfoPem()
+				["preferredUsername"] = Name,
-			}
+				["inbox"] = Id + "/inbox",
-		};
+				["followers"] = Id + "/followers",
+				["outbox"] = Id + "/outbox",
+				["featured"] = Id + "/featured",
+				["publicKey"] = new JsonObject
+				{
+					["id"] = KeyId,
+					["owner"] = Id,
+					["publicKeyPem"] = _key.ExportSubjectPublicKeyInfoPem()
+				}
+			};
+			if (_namesSharedInbox)
+				document["endpoints"] = new JsonObject { ["sharedInbox"] = SharedInbox };
+			if (_hasWall)
+				document["wall"] = Wall;
+			if (_ed25519 != default)
+				document["assertionMethod"] = new JsonArray(new JsonObject
+				{
+					["id"] = Id + "#ed25519-key", ["type"] = "Multikey", ["controller"] = Id,
+					["publicKeyMultibase"] = PrivaPub.Federation.Signing.IntegrityProofs.Multikey(PrivaPub.Federation.Signing.IntegrityProofs.PublicKey(_ed25519))
+				});
+			return document;
+		}
 
 		public HttpRequestMessage SignedGet(string path, string host = "privapub.test")
 		{
@@ -68,6 +102,22 @@ namespace PrivaPub.Tests.Support
 			return request;
 		}
 
+		// the same delivery signed as RFC 9421 does it (WordPress, Ghost, Fedify), for `signedFor` when it is not where the
+		// request goes
+		public HttpRequestMessage MessageSignedPost(string path, JsonNode activity, string signedFor = default, string origin = "https://privapub.test")
+		{
+			var body = Encoding.UTF8.GetBytes(activity.ToJsonString());
+			var request = new HttpRequestMessage(HttpMethod.Post, new Uri(origin + (signedFor ?? path))) { Content = new ByteArrayContent(body) };
+			request.Content.Headers.TryAddWithoutValidation("Content-Type", "application/activity+json");
+			MessageSignatures.Sign(request, KeyId, _key.ExportPkcs8PrivateKeyPem(), body);
+			request.RequestUri = new Uri(origin + path);
+			return request;
+		}
+
+		public string PrivateKeyPem => _key.ExportPkcs8PrivateKeyPem();
+
+		public string PublicKeyPem => _key.ExportSubjectPublicKeyInfoPem();
+
 		string Signature(string signingString, string headers)
 		{
 			var signature = Convert.ToBase64String(_key.SignData(Encoding.UTF8.GetBytes(signingString), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1));

PrivaPub/Api/Mastodon/Auth/OAuthSetup.cs

@@ -49,7 +49,14 @@ namespace PrivaPub.Api.Mastodon.Auth
 						.SetTokenEndpointUris("/oauth/token")
 						.SetRevocationEndpointUris("/oauth/revoke")
 						.SetConfigurationEndpointUris("/.well-known/openid-configuration", "/.well-known/oauth-authorization-server");
-					options.AllowAuthorizationCodeFlow().AllowClientCredentialsFlow();
+					options.AllowAuthorizationCodeFlow().AllowClientCredentialsFlow().AllowTokenExchangeFlow();
+					//the only subject token accepted is the root JWT, for PersonaExchange; OpenIddict's own tokens are not exchanged
+					options.Configure(server =>
+					{
+						server.SubjectTokenTypes.Clear();
+						server.SubjectTokenTypes.Add(PersonaExchange.SubjectTokenType);
+					});
+					options.AddEventHandler(RootJwtSubjectToken.Descriptor);
 					options.RegisterScopes(MastodonScopes.All);
 					options.UseReferenceAccessTokens();
 					options.SetAccessTokenLifetime(null);

PrivaPub/Api/Mastodon/Auth/PersonaExchange.cs

@@ -0,0 +1,105 @@
+using Microsoft.IdentityModel.Tokens;
+
+using OpenIddict.Abstractions;
+using OpenIddict.Server;
+
+using PrivaPub.Services;
+using PrivaPub.StaticServices;
+
+using System.Security.Claims;
+
+using static OpenIddict.Abstractions.OpenIddictConstants;
+using static OpenIddict.Server.OpenIddictServerEvents;
+
+namespace PrivaPub.Api.Mastodon.Auth
+{
+	// One sign-in for the first-party client (decePubClient): it signs in on /clientapi, then exchanges that root JWT for one
+	// persona's Mastodon token (RFC 8693, grant_type urn:ietf:params:oauth:grant-type:token-exchange, subject_token_type
+	// urn:ietf:params:oauth:token-type:jwt, avatar_id). Only the seeded first-party application holds the grant permission,
+	// and the issued token is the same kind the authorization code flow issues: subject the avatar, never the root.
+	public static class PersonaExchange
+	{
+		public const string SubjectTokenType = "urn:ietf:params:oauth:token-type:jwt";
+		public const string AvatarParameter = "avatar_id";
+		//the root the subject token belongs to; it lives on the subject token's principal only, which is never stored or issued
+		public const string RootClaim = "privapub_root";
+
+		public static string FirstPartyClientId(IConfiguration configuration) =>
+			configuration["ClientApi:FirstPartyClientId"] is { Length: > 0 } clientId ? clientId : "decepub";
+
+		//the first-party application: public (a browser keeps no secret), token exchange only, no redirect
+		public static async Task EnsureFirstPartyClient(IServiceProvider services, CancellationToken token)
+		{
+			using var scope = services.CreateScope();
+			var applications = scope.ServiceProvider.GetRequiredService<IOpenIddictApplicationManager>();
+			var clientId = FirstPartyClientId(scope.ServiceProvider.GetRequiredService<IConfiguration>());
+			var descriptor = new OpenIddictApplicationDescriptor
+			{
+				ClientId = clientId,
+				ClientType = ClientTypes.Public,
+				ConsentType = ConsentTypes.Implicit,
+				DisplayName = "decePubClient",
+				Permissions =
+				{
+					Permissions.Endpoints.Token,
+					Permissions.Endpoints.Revocation,
+					Permissions.GrantTypes.TokenExchange
+				}
+			};
+			foreach (var scopeName in new[] { "read", "write", "follow" })
+				descriptor.Permissions.Add(Permissions.Prefixes.Scope + scopeName);
+
+			var existing = await applications.FindByClientIdAsync(clientId, token);
+			if (existing == default)
+			{
+				await applications.CreateAsync(descriptor, token);
+				return;
+			}
+			await applications.PopulateAsync(existing, descriptor, token);
+			await applications.UpdateAsync(existing, token);
+		}
+	}
+
+	// Validates a root JWT given as a token exchange subject token, before OpenIddict tries it as one of its own tokens.
+	// The principal it builds names the root under PersonaExchange.RootClaim for TokenController, which signs in a fresh
+	// identity for the avatar.
+	public sealed class RootJwtSubjectToken : IOpenIddictServerHandler<ValidateTokenContext>
+	{
+		public static OpenIddictServerHandlerDescriptor Descriptor { get; } = OpenIddictServerHandlerDescriptor.CreateBuilder<ValidateTokenContext>()
+			.UseScopedHandler<RootJwtSubjectToken>()
+			.SetOrder(OpenIddictServerHandlers.Protection.ValidateIdentityModelToken.Descriptor.Order - 500)
+			.SetType(OpenIddictServerHandlerType.Custom)
+			.Build();
+
+		readonly IConfiguration _configuration;
+		readonly DbEntities _dbEntities;
+
+		public RootJwtSubjectToken(IConfiguration configuration, DbEntities dbEntities)
+		{
+			_configuration = configuration;
+			_dbEntities = dbEntities;
+		}
+
+		public async ValueTask HandleAsync(ValidateTokenContext context)
+		{
+			if (context.ValidTokenTypes.Count != 1 || !context.ValidTokenTypes.Contains(PersonaExchange.SubjectTokenType))
+				return;
+
+			var root = await RootJwt.Root(context.Token, _configuration, _dbEntities, context.Transaction.CancellationToken);
+			if (root == default)
+			{
+				context.Reject(Errors.InvalidGrant, "The session token is not valid.");
+				return;
+			}
+
+			var identity = new ClaimsIdentity(TokenValidationParameters.DefaultAuthenticationType, Claims.Name, Claims.Role);
+			identity.SetClaim(PersonaExchange.RootClaim, root.ID);
+			var principal = new ClaimsPrincipal(identity)
+				.SetTokenType(PersonaExchange.SubjectTokenType)
+				.SetCreationDate(DateTimeOffset.UtcNow);
+			if (context.ValidPresenters.Count > 0)
+				principal.SetPresenters(context.ValidPresenters);
+			context.Principal = principal;
+		}
+	}
+}

PrivaPub/Api/Mastodon/Auth/TokenController.cs

@@ -1,4 +1,4 @@
-using Microsoft.AspNetCore;
+using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.IdentityModel.Tokens;
@@ -48,9 +48,33 @@ namespace PrivaPub.Api.Mastodon.Auth
 				return SignIn(new ClaimsPrincipal(identity), OpenIddictServerAspNetCoreDefaults.AuthenticationScheme);
 			}
 
+			if (request.IsTokenExchangeGrantType())
+				return await Persona(request, token);
+
 			return Refuse(Errors.UnsupportedGrantType, "The grant type is not supported.");
 		}
 
+		//PersonaExchange: the root JWT, validated by RootJwtSubjectToken, for a token of one of the root's personas
+		async Task<IActionResult> Persona(OpenIddictRequest request, CancellationToken token)
+		{
+			var subject = (await HttpContext.AuthenticateAsync(OpenIddictServerAspNetCoreDefaults.AuthenticationScheme)).Principal;
+			var rootId = subject?.GetClaim(PersonaExchange.RootClaim);
+			var avatarId = (string)request[PersonaExchange.AvatarParameter];
+			if (string.IsNullOrEmpty(rootId) || string.IsNullOrEmpty(avatarId))
+				return Refuse(Errors.InvalidGrant, "The persona can no longer be used.");
+			var owns = await _dbEntities.RootToAvatars.Match(r => r.RootId == rootId && r.AvatarId == avatarId).ExecuteAnyAsync(token);
+			var avatar = owns ? await _dbEntities.Avatars.MatchID(avatarId).ExecuteFirstAsync(token) : default;
+			if (avatar == default || !await Usable(avatarId, token))
+				return Refuse(Errors.InvalidGrant, "The persona can no longer be used.");
+
+			var identity = new ClaimsIdentity(TokenValidationParameters.DefaultAuthenticationType, Claims.Name, Claims.Role);
+			identity.SetClaim(Claims.Subject, avatar.ID);
+			identity.SetClaim(Claims.Name, avatar.UserName);
+			identity.SetScopes(MastodonScopes.Parse(request.Scope).Intersect(new[] { "read", "write", "follow" }));
+			identity.SetDestinations(_ => new[] { Destinations.AccessToken });
+			return SignIn(new ClaimsPrincipal(identity), OpenIddictServerAspNetCoreDefaults.AuthenticationScheme);
+		}
+
 		async Task<bool> Usable(string avatarId, CancellationToken token)
 		{
 			if (string.IsNullOrEmpty(avatarId))

PrivaPub/Api/Mastodon/Controllers/AccountsController.cs

@@ -1,3 +1,4 @@
+using Microsoft.AspNetCore.RateLimiting;
 using Microsoft.AspNetCore.Mvc;
 
 using MongoDB.Entities;
@@ -16,6 +17,7 @@ using PrivaPub.Models.Post;
 using PrivaPub.Models.Social;
 using PrivaPub.Models.User;
 using PrivaPub.StaticServices;
+using PrivaPub.Infrastructure;
 
 using PostEntity = PrivaPub.Models.Post.Post;
 
@@ -30,10 +32,12 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		readonly IFollowService _follows;
 		readonly IOutboxPublisher _outbox;
 		readonly IRelationshipService _relationships;
+		readonly IFeedFollows _feeds;
 
 		public AccountsController(MastodonMapper mapper, DbEntities dbEntities, ILocalActorService localActors, IRemoteActorService remoteActors,
-			IFollowService follows, IOutboxPublisher outbox, IRelationshipService relationships)
+			IFollowService follows, IOutboxPublisher outbox, IRelationshipService relationships, IFeedFollows feeds)
 		{
+			_feeds = feeds;
 			_relationships = relationships;
 			_mapper = mapper;
 			_dbEntities = dbEntities;
@@ -46,18 +50,33 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		[HttpGet("/api/v1/accounts/verify_credentials"), Scope("read:accounts")]
 		public async Task<IActionResult> VerifyCredentials(CancellationToken token) => Json(await _mapper.Local(Me, withSource: true, token));
 
-		[HttpPatch("/api/v1/accounts/update_credentials"), Scope("write:accounts"), RequestSizeLimit(20 * 1024 * 1024),
+		[HttpPatch("/api/v1/accounts/update_credentials"), Scope("write:accounts"), EnableRateLimiting(RateLimiting.Uploads), RequestSizeLimit(20 * 1024 * 1024),
 			RequestFormLimits(MultipartBodyLengthLimit = 20 * 1024 * 1024)]
 		public async Task<IActionResult> UpdateCredentials([FromServices] IMediaService media, CancellationToken token)
 		{
 			var avatar = await _dbEntities.Avatars.MatchID(Me.Id).ExecuteFirstAsync(token);
+			// a new picture is a row of its own; the one it replaces goes to the trash once the profile is saved
+			var replaced = new List<Models.Media.MediaAttachment>();
 			if (Request.HasFormContentType)
 			{
 				var form = await Request.ReadFormAsync(token);
-				if (form.Files["avatar"] is { } picture && await media.ProfileImage(picture, 400, 400, token) is { } pictureUrl)
+				foreach (var (field, kind, width, height) in new[] { ("avatar", "avatar", 400, 400), ("header", "header", 1500, 500) })
-					avatar.PictureURL = pictureUrl;
+				{
-				if (form.Files["header"] is { } header && await media.ProfileImage(header, 1500, 500, token) is { } headerUrl)
+					if (form.Files[field] is not { } file)
-					avatar.ThumbnailURL = headerUrl;
+						continue;
+					var outcome = await media.ProfileImage(avatar.ID, kind, file, width, height, token);
+					if (!outcome.Ok)
+					{
+						foreach (var made in replaced)
+							await media.Trash(m => m.ID == made.ID, "profile not saved", token);
+						return Error(outcome.Status, outcome.Error);
+					}
+					replaced.Add(outcome.Attachment);
+					if (kind == "avatar")
+						avatar.PictureURL = media.Url(outcome.Attachment.FilePath);
+					else
+						avatar.ThumbnailURL = media.Url(outcome.Attachment.FilePath);
+				}
 			}
 			if (Params.Has("display_name"))
 				avatar.Name = Params.Get("display_name")?.Trim();
@@ -71,8 +90,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				avatar.Settings.IsDiscoverable = discoverable;
 			if (Params.Bool("indexable") is { } indexable)
 				avatar.Settings.IsIndexable = indexable;
-			if (Params.Bool("hide_collections") is { } hide)
+			// hide_collections stays true: who follows whom is never listed here, only counted (FEDERATION.md)
-				avatar.Settings.HideCollections = hide;
 			if (Params.Get("source[privacy]") is { } privacy && privacy is "public" or "unlisted" or "private")
 				avatar.Settings.DefaultVisibility = privacy;
 			if (Params.Bool("source[sensitive]") is { } sensitive)
@@ -99,12 +117,36 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				avatar.Fields = fields;
 			avatar.UpdatedAt = DateTime.UtcNow;
 			await DB.Default.SaveAsync(avatar, token);
+			foreach (var made in replaced)
+				await media.Trash(m => m.ProfileOfAvatarId == avatar.ID && m.Kind == made.Kind && m.ID != made.ID, "replaced", token);
 
 			var actor = _localActors.FromAvatar(avatar);
 			await _outbox.PublishProfile(actor, token);
 			return Json(await _mapper.Local(actor, withSource: true, token));
 		}
 
+		// Mastodon's: the picture goes (to the trash), the profile shows the default again, and followers are told
+		[HttpDelete("/api/v1/profile/avatar"), Scope("write:accounts")]
+		public Task<IActionResult> DeleteAvatar([FromServices] IMediaService media, CancellationToken token) => DeletePicture(media, "avatar", token);
+
+		[HttpDelete("/api/v1/profile/header"), Scope("write:accounts")]
+		public Task<IActionResult> DeleteHeader([FromServices] IMediaService media, CancellationToken token) => DeletePicture(media, "header", token);
+
+		async Task<IActionResult> DeletePicture(IMediaService media, string kind, CancellationToken token)
+		{
+			var avatar = await _dbEntities.Avatars.MatchID(Me.Id).ExecuteFirstAsync(token);
+			if (kind == "avatar")
+				avatar.PictureURL = default;
+			else
+				avatar.ThumbnailURL = default;
+			avatar.UpdatedAt = DateTime.UtcNow;
+			await DB.Default.SaveAsync(avatar, token);
+			await media.Trash(m => m.ProfileOfAvatarId == avatar.ID && m.Kind == kind, "removed", token);
+			var actor = _localActors.FromAvatar(avatar);
+			await _outbox.PublishProfile(actor, token);
+			return Json(await _mapper.Local(actor, withSource: true, token));
+		}
+
 		[HttpGet("/api/v1/accounts/lookup"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Lookup(CancellationToken token)
 		{
@@ -116,11 +158,11 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			if (parts.Length == 1 || parts[1].Equals(localDomain, StringComparison.OrdinalIgnoreCase))
 			{
 				var local = await _localActors.FindByUserName(parts[0], token);
-				return local is { IsFederated: true, IsCircle: false, Kind: not LocalActorKind.Application } ? Json(await _mapper.Local(local, false, token)) : NotFoundError();
+				return local is { IsFederated: true, IsCircle: false, IsServerActor: false } ? Json(await _mapper.Local(local, false, token)) : NotFoundError();
 			}
 			var userName = parts[0];
 			var domain = parts[1].ToLowerInvariant();
-			var foreign = await _dbEntities.ForeignAvatars.Match(f => f.UserName == userName && f.Domain == domain).ExecuteFirstAsync(token);
+			var foreign = await _dbEntities.ForeignAvatars.Match(f => f.UserName == userName && f.Domain == domain && !f.DeletionAt.HasValue).ExecuteFirstAsync(token);
 			return foreign == default ? NotFoundError() : Json(_mapper.Foreign(foreign));
 		}
 
@@ -135,7 +177,9 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		[HttpGet("/api/v1/accounts/search"), Scope("read:accounts")]
 		public async Task<IActionResult> Search([FromServices] AccountSearch search, CancellationToken token) =>
-			Json(await search.Find(Params.Get("q"), Params.Bool("resolve") == true && MyId != default, Limit(), token));
+			Json(Params.Bool("following") == true && MyId != default
+				? await search.Followed(MyId, Params.Get("q"), Limit(), token)
+				: await search.Find(Params.Get("q"), Params.Bool("resolve") == true && MyId != default, Limit(), token));
 
 		[HttpGet("/api/v1/accounts/{id}"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Get(string id, CancellationToken token)
@@ -153,7 +197,12 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			if (Params.Bool("pinned") == true)
 			{
 				if (local == default)
-					return Json(Array.Empty<Status>());
+				{
+					var featured = (await DB.Default.Find<RemoteFeatured>().Match(f => f.ActorURI == remote.ActorURI).Sort(f => f.Position, Order.Ascending)
+						.Limit(Federation.Actors.FeaturedPosts.MaxFeatured).ExecuteAsync(token)).Select(f => f.PostId).ToList();
+					var featuredPosts = await _dbEntities.Posts.Match(p => featured.Contains(p.ID) && !p.DeletedAt.HasValue).Match(VisibilityPolicy.IsPublic).ExecuteAsync(token);
+					return Json(await _mapper.Statuses(featured.Select(id => featuredPosts.FirstOrDefault(p => p.ID == id)).Where(p => p != default).ToList(), MyId, token));
+				}
 				var pinIds = (await DB.Default.Find<Pin>().Match(p => p.AvatarId == local.Id).Sort(p => p.ID, Order.Descending).ExecuteAsync(token)).Select(p => p.PostId).ToList();
 				var pinnedPosts = await _dbEntities.Posts.Match(p => pinIds.Contains(p.ID)).Match(VisibilityPolicy.IsPublic).ExecuteAsync(token);
 				return Json(await _mapper.Statuses(pinIds.Select(id => pinnedPosts.FirstOrDefault(p => p.ID == id)).Where(p => p != default).ToList(), MyId, token));
@@ -197,29 +246,49 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			var (local, _) = await Find(id, token);
 			if (local == default || local.Id != MyId)
 				return Json(Array.Empty<Account>());
-			var followers = await _dbEntities.Followers.Match(f => f.LocalActorId == local.Id && f.LocalActorKind == local.Kind && f.IsAccepted)
+			var followers = await Page.From(Params, Limit(40, 80))
-				.Sort(f => f.ID, Order.Descending).Limit(Limit(40, 80)).ExecuteAsync(token);
+				.Fetch(_dbEntities.Followers.Match(f => f.LocalActorId == local.Id && f.LocalActorKind == local.Kind && f.IsAccepted), f => f.ID, token);
+			Link($"/api/v1/accounts/{id}/followers", followers.LastOrDefault()?.ID, followers.FirstOrDefault()?.ID);
 			return Json(await AccountsFor(followers.Select(f => f.ActorURI), token));
 		}
 
 		[HttpGet("/api/v1/accounts/{id}/following"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Following(string id, CancellationToken token)
 		{
-			var (local, _) = await Find(id, token);
+			var (local, remote) = await Find(id, token);
+			// a feed's following is what it is: its communities, as its server lists them
+			if (remote is { AvatarType: AvatarType.Feed })
+				return Json(await AccountsFor(remote.FeedCommunities.Take(Limit(40, 80)), token));
 			if (local == default || local.Id != MyId)
 				return Json(Array.Empty<Account>());
-			var following = await _dbEntities.Followings.Match(f => f.AvatarId == local.Id && f.State == FollowState.Accepted)
+			var following = await Page.From(Params, Limit(40, 80))
-				.Sort(f => f.ID, Order.Descending).Limit(Limit(40, 80)).ExecuteAsync(token);
+				.Fetch(_dbEntities.Followings.Match(f => f.AvatarId == local.Id && f.State == FollowState.Accepted), f => f.ID, token);
+			Link($"/api/v1/accounts/{id}/following", following.LastOrDefault()?.ID, following.FirstOrDefault()?.ID);
 			var accounts = await _mapper.Accounts(following.Select(f => f.TargetAccountId), token);
 			return Json(following.Select(f => accounts.GetValueOrDefault(f.TargetAccountId)).Where(a => a != default).ToList());
 		}
 
+		// PrivaPub's own: the feeds the persona reads (a feed's timeline is /api/v1/timelines/feed/:id)
+		[HttpGet("/api/v1/feeds"), Scope("read:follows")]
+		public async Task<IActionResult> Feeds(CancellationToken token)
+		{
+			var read = await DB.Default.Find<FeedSubscription>().Match(s => s.AvatarId == MyId).Sort(s => s.ID, MongoDB.Entities.Order.Descending).ExecuteAsync(token);
+			var accounts = await _mapper.Accounts(read.Select(s => s.FeedAccountId), token);
+			return Json(read.Select(s => accounts.GetValueOrDefault(s.FeedAccountId)).Where(a => a != default).ToList());
+		}
+
 		[HttpPost("/api/v1/accounts/{id}/follow"), Scope("write:follows")]
 		public async Task<IActionResult> Follow(string id, CancellationToken token)
 		{
 			var (local, remote) = await Find(id, token);
 			if (local == default && remote == default)
 				return NotFoundError();
+			// a feed is read through the server, whose reader follows its communities; the persona follows nothing
+			if (remote is { AvatarType: AvatarType.Feed })
+			{
+				await _feeds.Subscribe(Me, remote, true, token);
+				return Json(await Relationship(id, token));
+			}
 			var following = await _follows.FollowAs(Me, local?.Uri ?? remote.ActorURI, Params.Bool("reblogs") != false, token);
 			return following == default ? Error(StatusCodes.Status403Forbidden, "This action is not allowed") : Json(await Relationship(id, token));
 		}
@@ -230,7 +299,10 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			var (local, remote) = await Find(id, token);
 			if (local == default && remote == default)
 				return NotFoundError();
-			await _follows.UnfollowAs(Me, local?.Uri ?? remote.ActorURI, token);
+			if (remote is { AvatarType: AvatarType.Feed })
+				await _feeds.Subscribe(Me, remote, false, token);
+			else
+				await _follows.UnfollowAs(Me, local?.Uri ?? remote.ActorURI, token);
 			return Json(await Relationship(id, token));
 		}
 
@@ -341,9 +413,6 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		[HttpGet("/api/v1/accounts/{id}/featured_tags"), Scope("read:accounts", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public IActionResult FeaturedTags(string id) => Json(Array.Empty<object>());
 
-		[HttpGet("/api/v1/accounts/{id}/lists"), Scope("read:lists")]
-		public IActionResult Lists(string id) => Json(Array.Empty<object>());
-
 		[HttpGet("/api/v1/accounts/familiar_followers"), Scope("read:follows")]
 		public IActionResult FamiliarFollowers() => Json(Params.List("id").Select(id => new { id, accounts = Array.Empty<Account>() }).ToList());
 
@@ -381,11 +450,15 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			var (local, remote) = await Find(id, token);
 			var uri = local?.Uri ?? remote?.ActorURI;
 			var following = uri == default ? default : await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.TargetActorURI == uri).ExecuteFirstAsync(token);
+			var reading = remote is { AvatarType: AvatarType.Feed } && await _feeds.IsSubscribed(MyId, remote.ActorURI, token);
 			var followedBy = uri == default ? default : await _dbEntities.Followers.Match(f => f.LocalActorId == MyId && f.ActorURI == uri).ExecuteFirstAsync(token);
 			var blocking = uri != default && await DB.Default.Find<Block>().Match(b => b.AvatarId == MyId && b.TargetActorURI == uri).ExecuteAnyAsync(token);
 			var mute = uri == default ? default : await DB.Default.Find<Mute>().Match(m => m.AvatarId == MyId && m.TargetActorURI == uri).ExecuteFirstAsync(token);
-			var blockedBy = local != default && await DB.Default.Find<Block>().Match(b => b.AvatarId == local.Id && b.TargetActorURI == Me.Uri).ExecuteAnyAsync(token);
+			var blockedBy = local != default
-			var domainBlocked = remote != default && await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == MyId && b.Domain == remote.Domain).ExecuteAnyAsync(token);
+				? await DB.Default.Find<Block>().Match(b => b.AvatarId == local.Id && b.TargetActorURI == Me.Uri).ExecuteAnyAsync(token)
+				: remote != default && await DB.Default.Find<BlockedBy>().Match(b => b.AvatarId == MyId && b.ActorURI == remote.ActorURI).ExecuteAnyAsync(token);
+			var domainBlocked = remote != default && (await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == MyId).ExecuteAsync(token))
+				.Any(b => Hidden.Blocks(b.Domain, remote.ActorURI, remote.Domain));
 			return new Relationship
 			{
 				Id = id,
@@ -394,7 +467,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				Muting = mute != default && (mute.ExpiresAt == default || mute.ExpiresAt > DateTime.UtcNow),
 				MutingNotifications = mute?.HideNotifications == true,
 				DomainBlocking = domainBlocked,
-				Following = following?.State == FollowState.Accepted,
+				Following = following?.State == FollowState.Accepted || reading,
 				Requested = following?.State == FollowState.Requested,
 				ShowingReblogs = following?.ShowReblogs ?? false,
 				FollowedBy = followedBy?.IsAccepted == true,

PrivaPub/Api/Mastodon/Controllers/CdnsController.cs

@@ -0,0 +1,82 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Domain.Statistics;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// The CDNs in front of the servers this server knows, each named by its own domain (owner decision 2026-10-04): how many
+	// servers are behind it, how it is recognised, and week by week who joined and who left.
+	public class CdnsController : MastodonController
+	{
+		const int MaxWeeks = 260;
+
+		readonly IServerPlaces _places;
+
+		public CdnsController(IServerPlaces places) => _places = places;
+
+		[HttpGet("/api/privapub/v1/cdns"), Scope("read", requiresUser: false), AllowAnonymous]
+		public async Task<IActionResult> List(CancellationToken token) => Json((await _places.Cdns(token)).Select(Summary).ToList());
+
+		[HttpGet("/api/privapub/v1/cdns/{key}"), Scope("read", requiresUser: false), AllowAnonymous]
+		public async Task<IActionResult> Detail(string key, CancellationToken token)
+		{
+			var history = await _places.Cdn(key, Math.Clamp(Params.Int("weeks") ?? 52, 1, MaxWeeks), token);
+			if (history == default)
+				return NotFoundError();
+			var detail = new CdnDetail
+			{
+				Hosts = history.Hosts,
+				HostsTruncated = history.Group.Servers > history.Hosts.Count,
+				Weeks = history.Weeks.Select(w => new CdnWeekEntry { Week = w.Week, Servers = w.Servers, Joined = w.Joined, Left = w.Left }).ToList()
+			};
+			Fill(detail, history.Group);
+			return Json(detail);
+		}
+
+		static CdnSummary Summary(CdnGroup group)
+		{
+			var summary = new CdnSummary();
+			Fill(summary, group);
+			return summary;
+		}
+
+		static void Fill(CdnSummary summary, CdnGroup group)
+		{
+			summary.Key = group.Key;
+			summary.Name = group.Name;
+			summary.Domain = group.Domain;
+			summary.Servers = group.Servers;
+			summary.Ranges = group.Ranges;
+			summary.RangesUpdatedAt = group.RangesUpdatedAt is { } at ? MastodonJson.Time(at) : default;
+			summary.DetectedBy = group.DetectedBy;
+		}
+
+		public class CdnSummary
+		{
+			public string Key { get; set; }
+			public string Name { get; set; }
+			public string Domain { get; set; }
+			public int Servers { get; set; }
+			public int Ranges { get; set; }
+			public string RangesUpdatedAt { get; set; }
+			public List<string> DetectedBy { get; set; } = new();
+		}
+
+		public class CdnDetail : CdnSummary
+		{
+			public List<string> Hosts { get; set; } = new();
+			public bool HostsTruncated { get; set; }
+			public List<CdnWeekEntry> Weeks { get; set; } = new();
+		}
+
+		public class CdnWeekEntry
+		{
+			public string Week { get; set; }
+			public int Servers { get; set; }
+			public List<string> Joined { get; set; } = new();
+			public List<string> Left { get; set; } = new();
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/FiltersController.cs

@@ -0,0 +1,362 @@
+using System.Text.RegularExpressions;
+
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Bson;
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Entities;
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Domain.Social;
+using PrivaPub.Models.Social;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Mastodon's filters (owner decision 2026-10-04, back from the cut list): v2 filters with their keywords and statuses,
+	// and the v1 API, whose filter is one keyword of a v2 filter. Statuses carry what they match in `filtered`; clients
+	// apply the context and the action. Nothing here leaves the server.
+	public class FiltersController : MastodonController
+	{
+		const int MaxFilters = 100;
+		const int MaxEntries = 100;
+		const int MaxKeywordLength = 100;
+		static readonly Regex Attribute = new(@"^keywords_attributes\[(\d*)\]\[(\w+)\]$", RegexOptions.Compiled);
+
+		readonly DbEntities _dbEntities;
+
+		public FiltersController(DbEntities dbEntities)
+		{
+			_dbEntities = dbEntities;
+		}
+
+		static string NewId() => ObjectId.GenerateNewId().ToString();
+
+		Task<PersonaFilter> Mine(string id, CancellationToken token) =>
+			DB.Default.Find<PersonaFilter>().Match(f => f.ID == id && f.AvatarId == MyId).ExecuteFirstAsync(token);
+
+		Task<PersonaFilter> WithKeyword(string keywordId, CancellationToken token) =>
+			DB.Default.Find<PersonaFilter>().Match(f => f.AvatarId == MyId && f.Keywords.Any(k => k.Id == keywordId)).ExecuteFirstAsync(token);
+
+		Task<PersonaFilter> WithStatus(string statusFilterId, CancellationToken token) =>
+			DB.Default.Find<PersonaFilter>().Match(f => f.AvatarId == MyId && f.Statuses.Any(s => s.Id == statusFilterId)).ExecuteFirstAsync(token);
+
+		static JsonResult Invalid(string message) => Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: " + message);
+
+		// title, context[], filter_action, expires_in: what a create or an update sets; an error message when one is wrong
+		string Apply(PersonaFilter filter, bool creating)
+		{
+			var title = Params.Get("title")?.Trim();
+			if (title != default || creating)
+			{
+				if (string.IsNullOrEmpty(title) || title.Length > 200)
+					return "Title can't be blank";
+				filter.Title = title;
+			}
+			if (Params.Has("context") || creating)
+			{
+				var context = Params.List("context").Distinct().ToList();
+				if (context.Count == 0 || context.Any(c => !FilterContexts.IsValid(c)))
+					return "Context can't be blank";
+				filter.Context = context;
+			}
+			if (Params.Get("filter_action") is { } action)
+			{
+				if (!FilterActions.IsValid(action))
+					return "Filter action is not included in the list";
+				filter.Action = action;
+			}
+			if (Params.Has("expires_in"))
+				filter.ExpiresAt = Params.Int("expires_in") is > 0 and var seconds ? DateTime.UtcNow.AddSeconds(seconds) : default;
+			return default;
+		}
+
+		// keywords_attributes, as Rails takes them: a JSON array of objects, or form fields [][keyword], [][whole_word], [][id],
+		// [][_destroy], or numbered [0][keyword]
+		List<Dictionary<string, string>> KeywordAttributes()
+		{
+			if (Params.Json is { ValueKind: System.Text.Json.JsonValueKind.Object } body
+				&& body.TryGetProperty("keywords_attributes", out var array) && array.ValueKind == System.Text.Json.JsonValueKind.Array)
+				return array.EnumerateArray().Where(o => o.ValueKind == System.Text.Json.JsonValueKind.Object)
+					.Select(o => o.EnumerateObject().ToDictionary(p => p.Name, p => p.Value.ValueKind switch
+					{
+						System.Text.Json.JsonValueKind.String => p.Value.GetString(),
+						System.Text.Json.JsonValueKind.True => "true",
+						System.Text.Json.JsonValueKind.False => "false",
+						_ => p.Value.ToString()
+					}))
+					.ToList();
+			var numbered = new SortedDictionary<int, Dictionary<string, string>>();
+			var listed = new Dictionary<string, IReadOnlyList<string>>();
+			foreach (var name in Params.Names)
+			{
+				var match = Attribute.Match(name);
+				if (!match.Success)
+					continue;
+				if (match.Groups[1].Value.Length == 0)
+					listed[match.Groups[2].Value] = Params.List(name);
+				else
+				{
+					var index = int.Parse(match.Groups[1].Value);
+					if (!numbered.TryGetValue(index, out var item))
+						numbered[index] = item = new Dictionary<string, string>();
+					item[match.Groups[2].Value] = Params.Get(name);
+				}
+			}
+			var items = numbered.Values.ToList();
+			var count = listed.Count == 0 ? 0 : listed.Values.Max(v => v.Count);
+			for (var i = 0; i < count; i++)
+				items.Add(listed.Where(kv => i < kv.Value.Count).ToDictionary(kv => kv.Key, kv => kv.Value[i]));
+			return items;
+		}
+
+		static bool IsTrue(string value) => value?.ToLowerInvariant() is "true" or "1" or "on" or "yes";
+
+		// adds, changes or removes keywords; an error message when one is wrong
+		static string ApplyKeywords(PersonaFilter filter, List<Dictionary<string, string>> items)
+		{
+			foreach (var item in items)
+			{
+				var id = item.GetValueOrDefault("id");
+				var existing = id == default ? default : filter.Keywords.FirstOrDefault(k => k.Id == id);
+				if (existing != default && IsTrue(item.GetValueOrDefault("_destroy")))
+				{
+					filter.Keywords.Remove(existing);
+					continue;
+				}
+				var keyword = item.GetValueOrDefault("keyword")?.Trim();
+				if (existing == default && string.IsNullOrEmpty(keyword))
+					return "Keyword can't be blank";
+				if (keyword?.Length > MaxKeywordLength)
+					return "Keyword is too long";
+				var target = existing ?? new FilterKeyword { Id = NewId() };
+				if (!string.IsNullOrEmpty(keyword))
+					target.Keyword = keyword;
+				if (item.ContainsKey("whole_word"))
+					target.WholeWord = IsTrue(item["whole_word"]);
+				else if (existing == default)
+					target.WholeWord = true;
+				if (existing == default)
+					filter.Keywords.Add(target);
+			}
+			return filter.Keywords.Count > MaxEntries ? "Too many keywords" : default;
+		}
+
+		// -- v2
+
+		[HttpGet("/api/v2/filters"), Scope("read:filters")]
+		public async Task<IActionResult> All(CancellationToken token) =>
+			Json((await DB.Default.Find<PersonaFilter>().Match(f => f.AvatarId == MyId).Sort(f => f.ID, Order.Ascending).ExecuteAsync(token))
+				.Select(Filters.View).ToList());
+
+		[HttpGet("/api/v2/filters/{id}"), Scope("read:filters")]
+		public async Task<IActionResult> One(string id, CancellationToken token) =>
+			await Mine(id, token) is { } filter ? Json(Filters.View(filter)) : NotFoundError();
+
+		[HttpPost("/api/v2/filters"), Scope("write:filters")]
+		public async Task<IActionResult> Create(CancellationToken token)
+		{
+			if (await DB.Default.CountAsync<PersonaFilter>(f => f.AvatarId == MyId, token) >= MaxFilters)
+				return Invalid("Too many filters");
+			var filter = new PersonaFilter { AvatarId = MyId };
+			if ((Apply(filter, creating: true) ?? ApplyKeywords(filter, KeywordAttributes())) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(Filters.View(filter));
+		}
+
+		[HttpPut("/api/v2/filters/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> Update(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } filter)
+				return NotFoundError();
+			if ((Apply(filter, creating: false) ?? ApplyKeywords(filter, KeywordAttributes())) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(Filters.View(filter));
+		}
+
+		[HttpDelete("/api/v2/filters/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> Delete(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } filter)
+				return NotFoundError();
+			await DB.Default.DeleteAsync<PersonaFilter>(filter.ID);
+			return Json(new { });
+		}
+
+		[HttpGet("/api/v2/filters/{id}/keywords"), Scope("read:filters")]
+		public async Task<IActionResult> Keywords(string id, CancellationToken token) =>
+			await Mine(id, token) is { } filter ? Json(filter.Keywords.Select(Filters.Keyword).ToList()) : NotFoundError();
+
+		[HttpPost("/api/v2/filters/{id}/keywords"), Scope("write:filters")]
+		public async Task<IActionResult> AddKeyword(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } filter)
+				return NotFoundError();
+			var item = new Dictionary<string, string> { ["keyword"] = Params.Get("keyword") };
+			if (Params.Has("whole_word"))
+				item["whole_word"] = Params.Get("whole_word");
+			if (ApplyKeywords(filter, new List<Dictionary<string, string>> { item }) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(Filters.Keyword(filter.Keywords[^1]));
+		}
+
+		[HttpGet("/api/v2/filters/keywords/{id}"), Scope("read:filters")]
+		public async Task<IActionResult> Keyword(string id, CancellationToken token) =>
+			await WithKeyword(id, token) is { } filter ? Json(Filters.Keyword(filter.Keywords.First(k => k.Id == id))) : NotFoundError();
+
+		[HttpPut("/api/v2/filters/keywords/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> UpdateKeyword(string id, CancellationToken token)
+		{
+			if (await WithKeyword(id, token) is not { } filter)
+				return NotFoundError();
+			var item = new Dictionary<string, string> { ["id"] = id, ["keyword"] = Params.Get("keyword") };
+			if (Params.Has("whole_word"))
+				item["whole_word"] = Params.Get("whole_word");
+			if (ApplyKeywords(filter, new List<Dictionary<string, string>> { item }) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(Filters.Keyword(filter.Keywords.First(k => k.Id == id)));
+		}
+
+		[HttpDelete("/api/v2/filters/keywords/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> DeleteKeyword(string id, CancellationToken token)
+		{
+			if (await WithKeyword(id, token) is not { } filter)
+				return NotFoundError();
+			filter.Keywords.RemoveAll(k => k.Id == id);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(new { });
+		}
+
+		[HttpGet("/api/v2/filters/{id}/statuses"), Scope("read:filters")]
+		public async Task<IActionResult> Statuses(string id, CancellationToken token) =>
+			await Mine(id, token) is { } filter ? Json(filter.Statuses.Select(Filters.Status).ToList()) : NotFoundError();
+
+		// a status the persona can see, once per filter
+		[HttpPost("/api/v2/filters/{id}/statuses"), Scope("write:filters")]
+		public async Task<IActionResult> AddStatus(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } filter)
+				return NotFoundError();
+			var statusId = Params.Get("status_id");
+			var post = string.IsNullOrEmpty(statusId) ? default : await _dbEntities.Posts.Match(p => p.ID == statusId).ExecuteFirstAsync(token);
+			if (post == default || !await Domain.Privacy.VisibilityPolicy.CanSee(post, MyId, token))
+				return NotFoundError();
+			if (filter.Statuses.FirstOrDefault(s => s.PostId == statusId) is { } present)
+				return Json(Filters.Status(present));
+			if (filter.Statuses.Count >= MaxEntries)
+				return Invalid("Too many statuses");
+			var added = new FilterStatus { Id = NewId(), PostId = statusId };
+			filter.Statuses.Add(added);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(Filters.Status(added));
+		}
+
+		[HttpGet("/api/v2/filters/statuses/{id}"), Scope("read:filters")]
+		public async Task<IActionResult> Status(string id, CancellationToken token) =>
+			await WithStatus(id, token) is { } filter ? Json(Filters.Status(filter.Statuses.First(s => s.Id == id))) : NotFoundError();
+
+		[HttpDelete("/api/v2/filters/statuses/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> DeleteStatus(string id, CancellationToken token)
+		{
+			if (await WithStatus(id, token) is not { } filter)
+				return NotFoundError();
+			filter.Statuses.RemoveAll(s => s.Id == id);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(new { });
+		}
+
+		// -- v1: each keyword is a filter of its own, with its parent's context, action and expiry
+
+		static FilterV1Entity V1(PersonaFilter filter, FilterKeyword keyword) => new()
+		{
+			Id = keyword.Id,
+			Phrase = keyword.Keyword,
+			Context = filter.Context,
+			WholeWord = keyword.WholeWord,
+			ExpiresAt = filter.ExpiresAt.HasValue ? MastodonJson.Time(filter.ExpiresAt.Value) : default,
+			Irreversible = filter.Action == FilterActions.Hide
+		};
+
+		[HttpGet("/api/v1/filters"), Scope("read:filters")]
+		public async Task<IActionResult> AllV1(CancellationToken token) =>
+			Json((await DB.Default.Find<PersonaFilter>().Match(f => f.AvatarId == MyId).Sort(f => f.ID, Order.Ascending).ExecuteAsync(token))
+				.SelectMany(f => f.Keywords.Select(k => V1(f, k))).ToList());
+
+		[HttpGet("/api/v1/filters/{id}"), Scope("read:filters")]
+		public async Task<IActionResult> OneV1(string id, CancellationToken token) =>
+			await WithKeyword(id, token) is { } filter ? Json(V1(filter, filter.Keywords.First(k => k.Id == id))) : NotFoundError();
+
+		// phrase, context[], irreversible, whole_word, expires_in
+		string ApplyV1(PersonaFilter filter, FilterKeyword keyword, bool creating)
+		{
+			var phrase = Params.Get("phrase")?.Trim();
+			if (phrase != default || creating)
+			{
+				if (string.IsNullOrEmpty(phrase))
+					return "Phrase can't be blank";
+				if (phrase.Length > MaxKeywordLength)
+					return "Phrase is too long";
+				keyword.Keyword = phrase;
+				if (creating)
+					filter.Title = phrase;
+			}
+			if (Params.Has("context") || creating)
+			{
+				var context = Params.List("context").Distinct().ToList();
+				if (context.Count == 0 || context.Any(c => !FilterContexts.IsValid(c)))
+					return "Context can't be blank";
+				filter.Context = context;
+			}
+			if (Params.Bool("whole_word") is { } wholeWord)
+				keyword.WholeWord = wholeWord;
+			if (Params.Bool("irreversible") is { } irreversible)
+				filter.Action = irreversible ? FilterActions.Hide : FilterActions.Warn;
+			if (Params.Has("expires_in"))
+				filter.ExpiresAt = Params.Int("expires_in") is > 0 and var seconds ? DateTime.UtcNow.AddSeconds(seconds) : default;
+			return default;
+		}
+
+		[HttpPost("/api/v1/filters"), Scope("write:filters")]
+		public async Task<IActionResult> CreateV1(CancellationToken token)
+		{
+			if (await DB.Default.CountAsync<PersonaFilter>(f => f.AvatarId == MyId, token) >= MaxFilters)
+				return Invalid("Too many filters");
+			var keyword = new FilterKeyword { Id = NewId(), WholeWord = true };
+			var filter = new PersonaFilter { AvatarId = MyId, Keywords = new List<FilterKeyword> { keyword } };
+			if (ApplyV1(filter, keyword, creating: true) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(V1(filter, keyword));
+		}
+
+		[HttpPut("/api/v1/filters/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> UpdateV1(string id, CancellationToken token)
+		{
+			if (await WithKeyword(id, token) is not { } filter)
+				return NotFoundError();
+			var keyword = filter.Keywords.First(k => k.Id == id);
+			if (ApplyV1(filter, keyword, creating: false) is { } problem)
+				return Invalid(problem);
+			await DB.Default.SaveAsync(filter, token);
+			return Json(V1(filter, keyword));
+		}
+
+		// the keyword goes, and its filter with it when nothing else is left in it
+		[HttpDelete("/api/v1/filters/{id}"), Scope("write:filters")]
+		public async Task<IActionResult> DeleteV1(string id, CancellationToken token)
+		{
+			if (await WithKeyword(id, token) is not { } filter)
+				return NotFoundError();
+			filter.Keywords.RemoveAll(k => k.Id == id);
+			if (filter.Keywords.Count == 0 && filter.Statuses.Count == 0)
+				await DB.Default.DeleteAsync<PersonaFilter>(filter.ID);
+			else
+				await DB.Default.SaveAsync(filter, token);
+			return Json(new { });
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/InstanceController.cs

@@ -30,28 +30,54 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		bool Open => _registrations.CurrentValue.IsOpen;
 
+		// the languages this server is set up for (AppConfiguration:SupportedLanguages), "en" when none are named
+		public static IReadOnlyList<string> LanguageCodes(IServiceProvider services)
+		{
+			var configured = services.GetRequiredService<Microsoft.Extensions.Options.IOptionsMonitor<Models.AppConfiguration>>().CurrentValue.SupportedLanguages;
+			var codes = (configured ?? new List<string>()).Where(c => !string.IsNullOrWhiteSpace(c)).Select(c => c.Split('-')[0].ToLowerInvariant()).Distinct().ToList();
+			return codes.Count == 0 ? new[] { "en" } : codes;
+		}
+
 		string Domain => new Uri(_localActors.BaseAddress).Authority;
 
-		static object Statuses => new { max_characters = 5000, max_media_attachments = 4, characters_reserved_per_url = 23 };
+		// where clients open their streams (StreamingController): this server, as ws or wss
+		string Streaming => new UriBuilder(_localActors.BaseAddress) { Scheme = _localActors.BaseAddress.StartsWith("https", StringComparison.OrdinalIgnoreCase) ? "wss" : "ws" }
+			.Uri.GetLeftPart(UriPartial.Authority);
 
-		static object MediaAttachments => new
+		// every limit is what the server enforces, read from where it is enforced
+		static object Statuses => new { max_characters = PrivaPub.Domain.Statuses.StatusService.MaxCharacters, max_media_attachments = 4, characters_reserved_per_url = 23 };
+
+		object MediaAttachments
 		{
-			supported_mime_types = new[] { "image/jpeg", "image/png", "image/gif", "image/webp", "video/mp4", "video/webm", "audio/mpeg", "audio/ogg" },
+			get
-			image_size_limit = 16 * 1024 * 1024,
+			{
-			image_matrix_limit = 16_777_216,
+				var media = HttpContext.RequestServices.GetRequiredService<IOptionsMonitor<PrivaPub.Domain.Media.MediaOptions>>().CurrentValue;
-			video_size_limit = 99 * 1024 * 1024,
+				return new
-			video_frame_rate_limit = 60,
+				{
-			video_matrix_limit = 2_304_000
+					supported_mime_types = PrivaPub.Domain.Media.MediaService.SupportedTypes,
-		};
+					image_size_limit = media.MaxImageBytes,
+					image_matrix_limit = media.MaxPixels,
+					video_size_limit = media.MaxVideoBytes,
+					video_frame_rate_limit = (int)media.MaxFrameRate,
+					video_matrix_limit = media.MaxVideoPixels
+				};
+			}
+		}
 
-		static object Polls => new { max_options = 4, max_characters_per_option = 50, min_expiration = 300, max_expiration = 2_629_746 };
+		static object Polls => new
+		{
+			max_options = PrivaPub.Domain.Statuses.PollService.MaxOptions,
+			max_characters_per_option = PrivaPub.Domain.Statuses.PollService.MaxOptionLength,
+			min_expiration = PrivaPub.Domain.Statuses.PollService.MinExpiration,
+			max_expiration = PrivaPub.Domain.Statuses.PollService.MaxExpiration
+		};
 
 		[HttpGet("/api/v1/instance"), AllowAnonymous]
 		public async Task<IActionResult> V1(CancellationToken token)
 		{
-			var users = await DB.Default.CountAsync<Avatar>(a => !a.DeletionAt.HasValue, token);
+			var users = await Counted.Users(token);
-			var statuses = await DB.Default.CountAsync<PostEntity>(f => f.Where(p => !p.IsFederatedCopy) & f.Where(VisibilityPolicy.IsPublic), token);
+			var statuses = await Counted.LocalPosts(token);
-			var domains = (await DB.Default.Find<ForeignAvatar, string>().Project(a => a.Domain).ExecuteAsync(token)).Distinct().Count();
+			var domains = await KnownServers(token);
 			return Json(new
 			{
 				uri = Domain,
@@ -60,10 +86,10 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				description = Description,
 				email = string.Empty,
 				version = Version,
-				urls = new { streaming_api = $"wss://{Domain}" },
+				urls = new { streaming_api = Streaming },
 				stats = new { user_count = users, status_count = statuses, domain_count = domains },
 				thumbnail = $"{_localActors.BaseAddress}/media/missing-header.png",
-				languages = new[] { "en" },
+				languages = LanguageCodes(HttpContext.RequestServices),
 				registrations = Open,
 				approval_required = false,
 				invites_enabled = true,//a group invitation always creates an account
@@ -73,8 +99,14 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			});
 		}
 
+		// the servers we have exchanged activities with, as the statistics count them. Which ones is not published
+		// (/instance/peers stays empty, as on a Mastodon with its peers API off): on a small server it would say who its
+		// personas talk to.
+		static async Task<long> KnownServers(CancellationToken token) =>
+			await DB.Default.CountAsync<Models.Jobs.RemoteInstance>(i => i.Seen == "touched", token);
+
 		[HttpGet("/api/v2/instance"), AllowAnonymous]
-		public IActionResult V2() => Json(new
+		public async Task<IActionResult> V2(CancellationToken token) => Json(new
 		{
 			domain = Domain,
 			title = "PrivaPub",
@@ -82,13 +114,13 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			api_versions = new { mastodon = 7 },
 			source_url = "https://git.thepra.dev/thepra/SocialPub",
 			description = Description,
-			usage = new { users = new { active_month = 0 } },
+			usage = new { users = new { active_month = await Counted.ActiveUsers(30, token) } },
 			thumbnail = new { url = $"{_localActors.BaseAddress}/media/missing-header.png" },
-			languages = new[] { "en" },
+			languages = LanguageCodes(HttpContext.RequestServices),
 			configuration = new
 			{
-				urls = new { streaming = $"wss://{Domain}" },
+				urls = new { streaming = Streaming },
-				accounts = new { max_featured_tags = 0, max_pinned_statuses = 0 },
+				accounts = new { max_featured_tags = 0, max_pinned_statuses = StatusesController.MaxPins },
 				statuses = Statuses,
 				media_attachments = MediaAttachments,
 				polls = Polls,

PrivaPub/Api/Mastodon/Controllers/ListsController.cs

@@ -0,0 +1,189 @@
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Domain.Privacy;
+using PrivaPub.Models.Social;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Mastodon's lists (owner decision 2026-10-04, back from the cut list): a persona groups accounts it follows, reads them
+	// as a timeline, and may keep an exclusive list's members out of its home. Nothing here leaves the server.
+	public class ListsController : MastodonController
+	{
+		const int MaxLists = 50;
+		const int MaxMembers = 500;
+
+		readonly DbEntities _dbEntities;
+		readonly MastodonMapper _mapper;
+
+		public ListsController(DbEntities dbEntities, MastodonMapper mapper)
+		{
+			_dbEntities = dbEntities;
+			_mapper = mapper;
+		}
+
+		static object View(PersonaList list) => new { id = list.ID, title = list.Title, replies_policy = list.RepliesPolicy, exclusive = list.Exclusive };
+
+		Task<PersonaList> Mine(string id, CancellationToken token) =>
+			DB.Default.Find<PersonaList>().Match(l => l.ID == id && l.AvatarId == MyId).ExecuteFirstAsync(token);
+
+		// a list holds only accounts the persona still follows: whatever ended the follow (an unfollow, a Reject, a Block, the
+		// account's deletion), its membership goes with it, pruned here on the next read
+		async Task<List<string>> Members(PersonaList list, CancellationToken token)
+		{
+			var members = (await DB.Default.Find<PersonaListMember>().Match(m => m.ListId == list.ID).ExecuteAsync(token)).Select(m => m.AccountId).ToList();
+			if (members.Count == 0)
+				return members;
+			var followed = (await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.State == FollowState.Accepted && members.Contains(f.TargetAccountId))
+				.ExecuteAsync(token)).Select(f => f.TargetAccountId).ToHashSet();
+			var gone = members.Where(m => !followed.Contains(m)).ToList();
+			if (gone.Count > 0)
+				await DB.Default.DeleteAsync<PersonaListMember>(m => m.ListId == list.ID && gone.Contains(m.AccountId));
+			return members.Where(followed.Contains).ToList();
+		}
+
+		[HttpGet("/api/v1/lists"), Scope("read:lists")]
+		public async Task<IActionResult> All(CancellationToken token) =>
+			Json((await DB.Default.Find<PersonaList>().Match(l => l.AvatarId == MyId).Sort(l => l.Title, MongoDB.Entities.Order.Ascending)
+				.ExecuteAsync(token)).Select(View).ToList());
+
+		[HttpGet("/api/v1/lists/{id}"), Scope("read:lists")]
+		public async Task<IActionResult> One(string id, CancellationToken token) =>
+			await Mine(id, token) is { } list ? Json(View(list)) : NotFoundError();
+
+		[HttpPost("/api/v1/lists"), Scope("write:lists")]
+		public async Task<IActionResult> Create(CancellationToken token)
+		{
+			var title = Params.Get("title")?.Trim();
+			var policy = Params.Get("replies_policy") ?? ListRepliesPolicy.List;
+			if (string.IsNullOrEmpty(title) || title.Length > 200)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Title can't be blank");
+			if (!ListRepliesPolicy.IsValid(policy))
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Replies policy is not included in the list");
+			if (await DB.Default.CountAsync<PersonaList>(l => l.AvatarId == MyId, token) >= MaxLists)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Too many lists");
+			var list = new PersonaList { AvatarId = MyId, Title = title, RepliesPolicy = policy, Exclusive = Params.Bool("exclusive") == true };
+			await DB.Default.SaveAsync(list, token);
+			return Json(View(list));
+		}
+
+		[HttpPut("/api/v1/lists/{id}"), Scope("write:lists")]
+		public async Task<IActionResult> Update(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			var title = Params.Get("title")?.Trim();
+			var policy = Params.Get("replies_policy");
+			if (title != default)
+			{
+				if (title.Length == 0 || title.Length > 200)
+					return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Title can't be blank");
+				list.Title = title;
+			}
+			if (policy != default)
+			{
+				if (!ListRepliesPolicy.IsValid(policy))
+					return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Replies policy is not included in the list");
+				list.RepliesPolicy = policy;
+			}
+			if (Params.Bool("exclusive") is { } exclusive)
+				list.Exclusive = exclusive;
+			await DB.Default.SaveAsync(list, token);
+			return Json(View(list));
+		}
+
+		[HttpDelete("/api/v1/lists/{id}"), Scope("write:lists")]
+		public async Task<IActionResult> Delete(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			await DB.Default.DeleteAsync<PersonaListMember>(m => m.ListId == list.ID);
+			await DB.Default.DeleteAsync<PersonaList>(list.ID);
+			return Json(new { });
+		}
+
+		[HttpGet("/api/v1/lists/{id}/accounts"), Scope("read:lists")]
+		public async Task<IActionResult> Accounts(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			await Members(list, token);
+			var members = await Page.From(Params, Limit(40, 80)).Fetch(DB.Default.Find<PersonaListMember>().Match(m => m.ListId == list.ID), m => m.ID, token);
+			var accounts = await _mapper.Accounts(members.Select(m => m.AccountId), token);
+			Link($"/api/v1/lists/{id}/accounts", members.LastOrDefault()?.ID, members.FirstOrDefault()?.ID);
+			return Json(members.Where(m => accounts.ContainsKey(m.AccountId)).Select(m => accounts[m.AccountId]).ToList());
+		}
+
+		// only accounts the persona follows may join its list, as on Mastodon
+		[HttpPost("/api/v1/lists/{id}/accounts"), Scope("write:lists")]
+		public async Task<IActionResult> Add(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			var ids = Params.List("account_ids").Distinct().ToList();
+			if (ids.Count == 0)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Account ids can't be blank");
+			var followed = (await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.State == FollowState.Accepted && ids.Contains(f.TargetAccountId))
+				.ExecuteAsync(token)).Select(f => f.TargetAccountId).ToHashSet();
+			if (ids.Any(a => !followed.Contains(a)))
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: You must follow this account to add it to a list");
+			var present = (await DB.Default.Find<PersonaListMember>().Match(m => m.ListId == list.ID && ids.Contains(m.AccountId)).ExecuteAsync(token))
+				.Select(m => m.AccountId).ToHashSet();
+			if (await DB.Default.CountAsync<PersonaListMember>(m => m.ListId == list.ID, token) + ids.Count(a => !present.Contains(a)) > MaxMembers)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Too many accounts in the list");
+			foreach (var account in ids.Where(a => !present.Contains(a)))
+				await DB.Default.SaveAsync(new PersonaListMember { ListId = list.ID, AvatarId = MyId, AccountId = account }, token);
+			return Json(new { });
+		}
+
+		[HttpDelete("/api/v1/lists/{id}/accounts"), Scope("write:lists")]
+		public async Task<IActionResult> Remove(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			var ids = Params.List("account_ids");
+			await DB.Default.DeleteAsync<PersonaListMember>(m => m.ListId == list.ID && ids.Contains(m.AccountId));
+			return Json(new { });
+		}
+
+		[HttpGet("/api/v1/accounts/{id}/lists"), Scope("read:lists")]
+		public async Task<IActionResult> Containing(string id, CancellationToken token)
+		{
+			var listIds = (await DB.Default.Find<PersonaListMember>().Match(m => m.AvatarId == MyId && m.AccountId == id).ExecuteAsync(token))
+				.Select(m => m.ListId).ToList();
+			return Json((await DB.Default.Find<PersonaList>().Match(l => l.AvatarId == MyId && listIds.Contains(l.ID)).ExecuteAsync(token))
+				.Select(View).ToList());
+		}
+
+		// the list's timeline: the persona's home entries by its members. Replies are kept as Mastodon keeps them: a member's
+		// replies to itself and to the persona always, to others as the policy says (anyone followed, the list's members, no one)
+		[HttpGet("/api/v1/timelines/list/{id}"), Scope("read:lists")]
+		public async Task<IActionResult> Timeline(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } list)
+				return NotFoundError();
+			var members = await Members(list, token);
+			var entries = await Page.From(Params, Limit()).Fetch(
+				_dbEntities.TimelineEntries.Match(e => e.AvatarId == MyId && members.Contains(e.AuthorAccountId)), e => e.PostId, token);
+			var ids = entries.Select(e => e.PostId).ToList();
+			var posts = (await _dbEntities.Posts.Match(p => ids.Contains(p.ID)).Match(VisibilityPolicy.IsShown).ExecuteAsync(token)).ToDictionary(p => p.ID);
+			var answered = list.RepliesPolicy switch
+			{
+				ListRepliesPolicy.Followed => (await _dbEntities.Followings.Match(f => f.AvatarId == MyId && f.State == FollowState.Accepted).ExecuteAsync(token))
+					.Select(f => f.TargetAccountId).Append(MyId).ToHashSet(),
+				ListRepliesPolicy.List => members.Append(MyId).ToHashSet(),
+				_ => new HashSet<string> { MyId }
+			};
+			var shown = ids.Where(posts.ContainsKey).Select(i => posts[i])
+				.Where(p => p.ReblogOfPostId != default || string.IsNullOrEmpty(p.AnsweringToPostId) && string.IsNullOrEmpty(p.InReplyToURI)
+					|| p.InReplyToAccountId != default && (p.InReplyToAccountId == p.AuthorAccountId || answered.Contains(p.InReplyToAccountId)))
+				.ToList();
+			Link($"/api/v1/timelines/list/{id}", entries.LastOrDefault()?.PostId, entries.FirstOrDefault()?.PostId);
+			return Json(await _mapper.Statuses(shown, MyId, token));
+		}
+	}
+}