PieFed and Mbin take reports from the reporter too

Both speak Lemmy's shapes and joined the servers that get reports in that shape only once the pasture showed each keeps
one with its reason. By their source, PieFed dropped the instance actor's report (it makes a user only of a Person or a
Service) and Mbin kept it without the persona's words (it reads the reason from `summary` alone). With them in
`ServiceReportTakers`, each keeps the reports of a thread and of a comment from "Reports from privapub.test" with
alice's words, and none names her (piefed.sh and mbin.sh, 65 checks with the full sweep's 876). A report of a PieFed
account alone, which PieFed would take from the reporter, is not sent yet; INTEROP says so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

.gitignore

@@ -402,6 +402,8 @@ FodyWeavers.xsd
 PrivaPub/media-store/
 PrivaPub/media-store-proxy/
 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 +21,9 @@ 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. Both 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 +32,8 @@ 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 +86,14 @@ 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 +103,9 @@ 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 +168,28 @@ 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**;
@@ -198,22 +220,51 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
    Located posts (`LocalGeo`) are the only local-only posts.
 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`).
-11. **Every "may anyone see this" goes through `VisibilityPolicy.IsPublic`;** a persona-specific read uses `CanSee`, and
+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 +274,17 @@ 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), and up/down votes. 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.
 
@@ -256,8 +315,8 @@ 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 +332,8 @@ 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 +364,19 @@ 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 +406,8 @@ 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
@@ -409,6 +482,10 @@ 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 +508,10 @@ 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 +519,8 @@ 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 +533,7 @@ 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 +541,189 @@ 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 +731,45 @@ 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.**

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 +119,23 @@ 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.
 
 ## Groups
 
@@ -68,7 +143,8 @@ 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 +153,21 @@ 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`.
 
 ## Activities
 
@@ -88,28 +176,87 @@ 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) |
+| `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`, `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`.
 
 - **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 +266,8 @@ 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 +290,28 @@ 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 +335,19 @@ 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 +376,28 @@ 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 `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.
 - **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` and the reporter
+  `/peasants/privapub_reports`) 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 +406,38 @@ 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/ViewReport.cs

@@ -0,0 +1,20 @@
+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; }
+	}
+}

PrivaPub.ClientModels/Admin/ViewStatistics.cs

@@ -0,0 +1,89 @@
+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 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.Tests/Domain/ContentRendererTests.cs

@@ -68,7 +68,9 @@ 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<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/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/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/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()
 		{

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 +366,159 @@ 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);
+		}
+
+		// 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 +111,138 @@ 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_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;
@@ -469,7 +601,7 @@ 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 +611,7 @@ 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 +665,42 @@ 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 +1,250 @@
+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" };
+
+		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 Payload, JsonObject Body)>> Queued() =>
+			(await DB.Default.Find<Job>().Match(j => j.Kind == JobKind.Deliver && j.CreatedAt >= DateTime.UtcNow.AddMinutes(-5)).ExecuteAsync(Token))
+				.Select(j => JsonSerializer.Deserialize<DeliveryPayload>(j.Payload))
+				.Select(p => (p, JsonNode.Parse(p.Body)!.AsObject()))
+				.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.Payload.Inbox != community.SharedInbox && q.Body.ToJsonString().Contains(post.ObjectURI));
+			Assert.DoesNotContain(alice.UserName, flag.ToJsonString());
+			Assert.DoesNotContain(alice.Id, flag.ToJsonString());
+			var queued = Assert.Single(await Queued(), q => q.Body["actor"]!.GetValue<string>() == reporter.Uri && q.Body["object"]!.GetValue<string>() == post.ObjectURI);
+			Assert.Equal(LocalActorKind.Reporter, queued.Payload.SignerKind);
+		}
+
+		[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/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/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 +41,10 @@ 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>()));
 			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 +70,16 @@ 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/MastodonScheduledStatusesTests.cs

@@ -0,0 +1,103 @@
+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);
+		}
+	}
+}

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($"/api/v1/statuses/{post.ID}")).Ok().Body;
+
+			Assert.Equal(post.ID, status.Text("id"));
+		}
+
+		// a reader who deletes the @name decePub prefills still answers its author: GoToSocial dropped such a reply, addressed
+		// to nobody there (found by decePub's e2e tests on the town)
+		[Fact]
+		public async Task A_reply_without_the_authors_name_still_names_the_author_in_cc()
+		{
+			var since = DateTime.UtcNow.AddSeconds(-1);
+			var alice = await _host.Mastodon("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			_peer.WebFinger(bob);
+			var parent = await _host.PublicPostFrom(bob, alice);
+
+			var reply = await alice.Status("no name in this one", ("in_reply_to_id", parent.ID));
+
+			Assert.Empty(reply["mentions"]!.AsArray());
+			var create = Assert.Single(await bob.Delivered(since), d => d.Type() == "Create");
+			Assert.Contains(bob.Id, Strings(create["object"]!["cc"]));
+		}
+
 		[Fact]
 		public async Task A_poll_is_created_validated_and_federated_as_a_question()
 		{
@@ -303,6 +388,59 @@ namespace PrivaPub.Tests.Http
 			Assert.True((await alice.Client.Post($"/api/v1/statuses/{quiet.Text("id")}/favourite")).Ok().Body.Flag("favourited"));
 		}
 
+		[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 +1,68 @@
+using PrivaPub.Tests.Support;
+using PrivaPub.Tests.Support.Host;
+
+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")));
+		}
+
+		// 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/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/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/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/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 +44,54 @@ 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 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 +118,15 @@ 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 +154,12 @@ 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 +23,8 @@ 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) };
 		static PrivaPubHost _shared;
 
 		readonly string _mediaRoot = Path.Combine(Path.GetTempPath(), $"privapub-tests-{Guid.NewGuid():N}");
@@ -75,6 +76,7 @@ namespace PrivaPub.Tests.Support.Host
 			["Federation:FetchLinkPreviews"] = "false",
 			["Registrations:Mode"] = "Open",
 			["Statistics:Geo:AutoUpdate"] = "false",
+			["Statistics:Cdn:AutoUpdate"] = "false",
 			["Media:Root"] = _mediaRoot,
 			["Logging:LogLevel:Default"] = "Warning",
 			["Serilog:MinimumLevel:Default"] = Environment.GetEnvironmentVariable("PRIVAPUB_TEST_LOGS") == "1" ? "Information" : "Fatal"

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());
 		}
 
@@ -28,14 +38,26 @@ 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)
+		{
+			activity["proof"] = PrivaPub.Federation.Signing.IntegrityProofs.Create(activity, Id + "#ed25519-key", _ed25519, DateTime.UtcNow);
+			return activity;
+		}
+
+		public JsonObject Document()
+		{
+			var document = new JsonObject
 			{
 				["id"] = Id,
 				["type"] = Type,
 				["preferredUsername"] = Name,
 				["inbox"] = Id + "/inbox",
 				["followers"] = Id + "/followers",
+				["outbox"] = Id + "/outbox",
+				["featured"] = Id + "/featured",
 				["publicKey"] = new JsonObject
 				{
 					["id"] = KeyId,
@@ -43,6 +65,18 @@ namespace PrivaPub.Tests.Support
 					["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

@@ -71,8 +71,7 @@ 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)
@@ -116,11 +115,11 @@ 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 +134,9 @@ 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 +154,12 @@ 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));
@@ -197,8 +203,9 @@ 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));
 		}
 
@@ -208,8 +215,9 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			var (local, _) = await Find(id, 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());
 		}
@@ -341,9 +349,6 @@ 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());
 
@@ -384,8 +389,11 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			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,

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
+				{
+					supported_mime_types = PrivaPub.Domain.Media.MediaService.SupportedTypes,
+					image_size_limit = media.MaxImageBytes,
+					image_matrix_limit = media.MaxImageSide * media.MaxImageSide,
+					video_size_limit = media.MaxVideoBytes,
 					video_frame_rate_limit = 60,
 					video_matrix_limit = 2_304_000
 				};
+			}
+		}
 
-		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));
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/MediaController.cs

@@ -101,12 +101,14 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return new EmptyResult();
 		}
 
-		object View(MediaAttachment attachment) => new
+		object View(MediaAttachment attachment) => View(_media, attachment);
+
+		internal static object View(IMediaService media, MediaAttachment attachment) => new
 		{
 			id = attachment.ID,
 			type = attachment.Kind,
-			url = _media.Url(attachment.FilePath),
+			url = media.Url(attachment.FilePath),
-			preview_url = _media.Url(attachment.PreviewPath ?? attachment.FilePath),
+			preview_url = media.Url(attachment.PreviewPath ?? attachment.FilePath),
 			remote_url = default(string),
 			text_url = default(string),
 			meta = new

PrivaPub/Api/Mastodon/Controllers/NotificationRequestsController.cs

@@ -0,0 +1,178 @@
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Domain.Social;
+using PrivaPub.Models.Social;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Mastodon's notification policy and requests (4.3): what the persona's notifications from strangers, new accounts,
+	// unasked private mentions and silenced accounts become, and the requests that gather the filtered ones, one per
+	// account, let in or dismissed
+	public class NotificationRequestsController : MastodonController
+	{
+		readonly MastodonMapper _mapper;
+		readonly DbEntities _dbEntities;
+
+		public NotificationRequestsController(MastodonMapper mapper, DbEntities dbEntities)
+		{
+			_mapper = mapper;
+			_dbEntities = dbEntities;
+		}
+
+		static string Name(NotificationAction action) => action switch
+		{
+			NotificationAction.Filter => "filter",
+			NotificationAction.Drop => "drop",
+			_ => "accept"
+		};
+
+		static NotificationAction? Parse(string value) => value?.ToLowerInvariant() switch
+		{
+			"accept" => NotificationAction.Accept,
+			"filter" => NotificationAction.Filter,
+			"drop" => NotificationAction.Drop,
+			_ => null
+		};
+
+		async Task<object> Summary(CancellationToken token) => new
+		{
+			pending_requests_count = await DB.Default.CountAsync<NotificationRequest>(r => r.AvatarId == MyId, token),
+			pending_notifications_count = await DB.Default.CountAsync<Notification>(n => n.AvatarId == MyId && n.Filtered, token)
+		};
+
+		async Task<object> V2(NotificationPolicy policy, CancellationToken token) => new
+		{
+			for_not_following = Name(policy.ForNotFollowing),
+			for_not_followers = Name(policy.ForNotFollowers),
+			for_new_accounts = Name(policy.ForNewAccounts),
+			for_private_mentions = Name(policy.ForPrivateMentions),
+			for_limited_accounts = Name(policy.ForLimitedAccounts),
+			summary = await Summary(token)
+		};
+
+		// the first version spoke of filtering only: dropped is filtered for it
+		async Task<object> V1(NotificationPolicy policy, CancellationToken token) => new
+		{
+			filter_not_following = policy.ForNotFollowing != NotificationAction.Accept,
+			filter_not_followers = policy.ForNotFollowers != NotificationAction.Accept,
+			filter_new_accounts = policy.ForNewAccounts != NotificationAction.Accept,
+			filter_private_mentions = policy.ForPrivateMentions != NotificationAction.Accept,
+			summary = await Summary(token)
+		};
+
+		[HttpGet("/api/v2/notifications/policy"), Scope("read:notifications")]
+		public async Task<IActionResult> Policy(CancellationToken token) => Json(await V2(await NotificationPolicies.Of(MyId, token), token));
+
+		[HttpPatch("/api/v2/notifications/policy"), Scope("write:notifications")]
+		public async Task<IActionResult> SetPolicy(CancellationToken token)
+		{
+			var policy = await NotificationPolicies.Of(MyId, token);
+			policy.ForNotFollowing = Parse(Params.Get("for_not_following")) ?? policy.ForNotFollowing;
+			policy.ForNotFollowers = Parse(Params.Get("for_not_followers")) ?? policy.ForNotFollowers;
+			policy.ForNewAccounts = Parse(Params.Get("for_new_accounts")) ?? policy.ForNewAccounts;
+			policy.ForPrivateMentions = Parse(Params.Get("for_private_mentions")) ?? policy.ForPrivateMentions;
+			policy.ForLimitedAccounts = Parse(Params.Get("for_limited_accounts")) ?? policy.ForLimitedAccounts;
+			await NotificationPolicies.Save(policy, token);
+			return Json(await V2(policy, token));
+		}
+
+		[HttpGet("/api/v1/notifications/policy"), Scope("read:notifications")]
+		public async Task<IActionResult> PolicyV1(CancellationToken token) => Json(await V1(await NotificationPolicies.Of(MyId, token), token));
+
+		[HttpPut("/api/v1/notifications/policy"), HttpPatch("/api/v1/notifications/policy"), Scope("write:notifications")]
+		public async Task<IActionResult> SetPolicyV1(CancellationToken token)
+		{
+			var policy = await NotificationPolicies.Of(MyId, token);
+			static NotificationAction Filter(bool? filter, NotificationAction current) =>
+				filter switch { true => current == NotificationAction.Drop ? NotificationAction.Drop : NotificationAction.Filter, false => NotificationAction.Accept, _ => current };
+			policy.ForNotFollowing = Filter(Params.Bool("filter_not_following"), policy.ForNotFollowing);
+			policy.ForNotFollowers = Filter(Params.Bool("filter_not_followers"), policy.ForNotFollowers);
+			policy.ForNewAccounts = Filter(Params.Bool("filter_new_accounts"), policy.ForNewAccounts);
+			policy.ForPrivateMentions = Filter(Params.Bool("filter_private_mentions"), policy.ForPrivateMentions);
+			await NotificationPolicies.Save(policy, token);
+			return Json(await V1(policy, token));
+		}
+
+		async Task<object> Map(NotificationRequest request, CancellationToken token)
+		{
+			var account = await _mapper.Account(request.FromAccountId, token);
+			if (account == default)
+				return default;
+			var post = string.IsNullOrEmpty(request.LastPostId) ? default
+				: await _dbEntities.Posts.Match(p => p.ID == request.LastPostId && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			return new
+			{
+				id = request.ID,
+				created_at = MastodonJson.Time(request.CreatedAt),
+				updated_at = MastodonJson.Time(request.UpdatedAt),
+				notifications_count = request.NotificationsCount.ToString(System.Globalization.CultureInfo.InvariantCulture),
+				account,
+				last_status = post == default ? default : await _mapper.Status(post, MyId, token)
+			};
+		}
+
+		[HttpGet("/api/v1/notifications/requests"), Scope("read:notifications")]
+		public async Task<IActionResult> Requests(CancellationToken token)
+		{
+			var requests = await Page.From(Params, Limit(40, 80)).Fetch(DB.Default.Find<NotificationRequest>().Match(r => r.AvatarId == MyId), r => r.ID, token);
+			Link("/api/v1/notifications/requests", requests.LastOrDefault()?.ID, requests.FirstOrDefault()?.ID);
+			var mapped = new List<object>();
+			foreach (var request in requests)
+				if (await Map(request, token) is { } one)
+					mapped.Add(one);
+			return Json(mapped);
+		}
+
+		Task<NotificationRequest> Mine(string id, CancellationToken token) =>
+			DB.Default.Find<NotificationRequest>().Match(r => r.ID == id && r.AvatarId == MyId).ExecuteFirstAsync(token);
+
+		[HttpGet("/api/v1/notifications/requests/merged"), Scope("read:notifications")]
+		public IActionResult Merged() => Json(new { merged = true });
+
+		[HttpGet("/api/v1/notifications/requests/{id}"), Scope("read:notifications")]
+		public async Task<IActionResult> Request(string id, CancellationToken token) =>
+			await Mine(id, token) is { } request && await Map(request, token) is { } mapped ? Json(mapped) : NotFoundError();
+
+		[HttpPost("/api/v1/notifications/requests/{id}/accept"), Scope("write:notifications")]
+		public async Task<IActionResult> Accept(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } request)
+				return NotFoundError();
+			await NotificationPolicies.Accept(request, token);
+			return Json(new { });
+		}
+
+		[HttpPost("/api/v1/notifications/requests/{id}/dismiss"), Scope("write:notifications")]
+		public async Task<IActionResult> Dismiss(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } request)
+				return NotFoundError();
+			await NotificationPolicies.Dismiss(request, token);
+			return Json(new { });
+		}
+
+		[HttpPost("/api/v1/notifications/requests/accept"), Scope("write:notifications")]
+		public async Task<IActionResult> AcceptMany(CancellationToken token)
+		{
+			foreach (var id in Params.List("id").Take(100))
+				if (await Mine(id, token) is { } request)
+					await NotificationPolicies.Accept(request, token);
+			return Json(new { });
+		}
+
+		[HttpPost("/api/v1/notifications/requests/dismiss"), Scope("write:notifications")]
+		public async Task<IActionResult> DismissMany(CancellationToken token)
+		{
+			foreach (var id in Params.List("id").Take(100))
+				if (await Mine(id, token) is { } request)
+					await NotificationPolicies.Dismiss(request, token);
+			return Json(new { });
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/ProvenanceController.cs

@@ -1,11 +1,16 @@
-using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
 
 using MongoDB.Entities;
 
 using PrivaPub.Api.Mastodon.Infrastructure;
 using PrivaPub.Domain.Privacy;
+using PrivaPub.Domain.Statistics;
+using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Objects;
+using PrivaPub.Infrastructure;
+using PrivaPub.Infrastructure.Geo;
 using PrivaPub.Models.Federation;
 using PrivaPub.Models.Jobs;
 using PrivaPub.Models.Post;
@@ -19,9 +24,25 @@ namespace PrivaPub.Api.Mastodon.Controllers
 {
 	public class ProvenanceController : MastodonController
 	{
-		readonly DbEntities _dbEntities;
+		const int MaxHosts = 40;
 
-		public ProvenanceController(DbEntities dbEntities) => _dbEntities = dbEntities;
+		readonly DbEntities _dbEntities;
+		const int MaxWeeks = 260;
+
+		readonly ISelfLocation _self;
+		readonly IServerPlaces _places;
+		readonly ILocalActorService _localActors;
+		readonly IOptionsMonitor<RegistrationOptions> _registrations;
+
+		public ProvenanceController(DbEntities dbEntities, ISelfLocation self, IServerPlaces places, ILocalActorService localActors,
+			IOptionsMonitor<RegistrationOptions> registrations)
+		{
+			_dbEntities = dbEntities;
+			_self = self;
+			_places = places;
+			_localActors = localActors;
+			_registrations = registrations;
+		}
 
 		[HttpGet("/api/privapub/v1/statuses/{id}/provenance"), Scope("read:statuses", requiresUser: false), AllowAnonymous]
 		public async Task<IActionResult> Status(string id, CancellationToken token)
@@ -38,18 +59,104 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				?? await DB.Default.Find<ObjectRecord>().Match(r => r.ObjectURI == post.ObjectURI).ExecuteFirstAsync(token);
 			var host = record?.Host ?? (Uri.TryCreate(post.ObjectURI, UriKind.Absolute, out var uri) ? uri.Host.ToLowerInvariant() : default);
 			var instance = host == default ? default : await DB.Default.Find<RemoteInstance>().Match(i => i.Host == host).ExecuteFirstAsync(token);
-			return Json(Describe(post, record, instance));
+			var beforeCdn = instance?.Geo?.Cdn == default ? default : (await _places.BeforeCdn(new[] { instance.Host }, token)).GetValueOrDefault(instance.Host);
+			return Json(Describe(post, record, instance, beforeCdn));
 		}
 
 		[HttpGet("/api/privapub/v1/instances/{host}"), Scope("read", requiresUser: false), AllowAnonymous]
 		public async Task<IActionResult> Instance(string host, CancellationToken token)
 		{
-			host = host?.Trim().ToLowerInvariant();
+			var described = await Describe(new[] { host }, token);
-			var instance = await DB.Default.Find<RemoteInstance>().Match(i => i.Host == host).ExecuteFirstAsync(token);
+			return described.Count == 0 ? NotFoundError() : Json(described[0]);
-			return instance == default ? NotFoundError() : Json(Describe(instance));
 		}
 
-		static Provenance Describe(PostEntity post, ObjectRecord record, RemoteInstance instance)
+		//up to MaxHosts at once (host[]=...), in the order asked; hosts this server does not know are left out
+		[HttpGet("/api/privapub/v1/instances"), Scope("read", requiresUser: false), AllowAnonymous]
+		public async Task<IActionResult> Instances(CancellationToken token) => Json(await Describe(Params.List("host"), token));
+
+		//the server's weekly snapshots, newest first (weeks=, at most MaxWeeks): its place as shown publicly, its CDN, its size
+		[HttpGet("/api/privapub/v1/instances/{host}/history"), Scope("read", requiresUser: false), AllowAnonymous]
+		public async Task<IActionResult> History(string host, CancellationToken token)
+		{
+			host = host?.Trim().ToLowerInvariant();
+			if (string.IsNullOrEmpty(host) || host.Length > 253 || !await DB.Default.Find<RemoteInstance>().Match(i => i.Host == host).ExecuteAnyAsync(token))
+				return NotFoundError();
+			var weeks = Math.Clamp(Params.Int("weeks") ?? 52, 1, MaxWeeks);
+			return Json((await _places.History(host, weeks, token)).Select(s => new InstanceWeek
+			{
+				Week = s.Week,
+				TakenAt = MastodonJson.Time(s.TakenAt),
+				Reachable = s.Reachable,
+				Software = s.Software,
+				Version = s.SoftwareVersion,
+				UsersTotal = s.UsersTotal,
+				UsersActiveMonth = s.UsersActiveMonth,
+				LocalPosts = s.LocalPosts,
+				OpenRegistrations = s.OpenRegistrations,
+				Geo = Located(PublicGeo.Project(new InstanceGeo
+				{
+					Country = s.Country, City = s.City, Latitude = s.Latitude, Longitude = s.Longitude, Asn = s.Asn,
+					Cdn = s.Cdn, CdnDomain = s.CdnDomain, CdnSource = s.CdnSource, Ipv6 = s.Ipv6
+				}), new InstanceGeo { Cdn = s.Cdn, CdnDomain = s.CdnDomain ?? CdnCatalog.ByKey(s.Cdn)?.Key, CdnSource = s.CdnSource })
+			}).ToList());
+		}
+
+		async Task<List<InstanceDescription>> Describe(IEnumerable<string> hosts, CancellationToken token)
+		{
+			var wanted = hosts.Select(h => h?.Trim().ToLowerInvariant()).Where(h => !string.IsNullOrEmpty(h) && h.Length <= 253)
+				.Distinct().Take(MaxHosts).ToList();
+			var selfHost = Uri.TryCreate(_localActors.BaseAddress, UriKind.Absolute, out var self) ? self.Host.ToLowerInvariant() : default;
+			var remote = await DB.Default.Find<RemoteInstance>().Match(i => wanted.Contains(i.Host)).ExecuteAsync(token);
+			var beforeCdn = await _places.BeforeCdn(remote.Where(i => i.Geo?.Cdn != default).Select(i => i.Host), token);
+			var described = new List<InstanceDescription>();
+			foreach (var host in wanted)
+			{
+				if (host == selfHost)
+					described.Add(await DescribeSelf(host, token));
+				else if (remote.FirstOrDefault(i => i.Host == host) is { } instance)
+					described.Add(Describe(instance, beforeCdn.GetValueOrDefault(host)));
+			}
+			return described;
+		}
+
+		async Task<InstanceDescription> DescribeSelf(string host, CancellationToken token)
+		{
+			var geo = await _self.Get(token);
+			return new InstanceDescription
+			{
+				Host = host,
+				Software = "privapub",
+				Version = BuildInfo.Ref,
+				NodeName = "PrivaPub",
+				Protocols = new() { "activitypub" },
+				OpenRegistrations = _registrations.CurrentValue.IsOpen,
+				DescribedAt = MastodonJson.Time(DateTime.UtcNow),
+				Geo = Located(PublicGeo.Project(geo), geo)
+			};
+		}
+
+		//the public projection of a server's place (PublicGeo); for a CDN-fronted one, the CDN's domain, how it was found and
+		//where the server was before it
+		static InstanceLocation Located(PublicLocation location, InstanceGeo geo, PlaceBeforeCdn beforeCdn = default) => location == default ? default : new InstanceLocation
+		{
+			Precision = location.Cdn != default ? "cdn" : location.Latitude != default ? "city" : "country",
+			Country = location.Country,
+			City = location.City,
+			Latitude = location.Latitude,
+			Longitude = location.Longitude,
+			Network = location.Network,
+			Cdn = location.Cdn,
+			CdnDomain = location.Cdn != default ? ServerPlaces.KeyOf(geo) : default,
+			CdnSource = location.Cdn != default ? geo?.CdnSource : default,
+			BeforeCdn = location.Cdn == default || beforeCdn == default ? default : new InstancePlace
+			{
+				Week = beforeCdn.Week, Country = beforeCdn.Country, City = beforeCdn.City, Latitude = beforeCdn.Latitude, Longitude = beforeCdn.Longitude
+			},
+			Source = geo?.Source,
+			LocatedAt = geo?.LocatedAt is { } at ? MastodonJson.Time(at) : default
+		};
+
+		Provenance Describe(PostEntity post, ObjectRecord record, RemoteInstance instance, PlaceBeforeCdn beforeCdn)
 		{
 			var raw = record?.Raw == default ? default : JsonNode.Parse(record.Raw) as JsonObject;
 			return new Provenance
@@ -86,11 +193,11 @@ namespace PrivaPub.Api.Mastodon.Controllers
 					RawHash = r.RawHash,
 					Raw = r.Raw == default ? default : JsonNode.Parse(r.Raw)
 				}).ToList() ?? new(),
-				Instance = instance == default ? default : Describe(instance)
+				Instance = instance == default ? default : Describe(instance, beforeCdn)
 			};
 		}
 
-		static InstanceDescription Describe(RemoteInstance instance) => new()
+		static InstanceDescription Describe(RemoteInstance instance, PlaceBeforeCdn beforeCdn) => new()
 		{
 			Host = instance.Host,
 			Software = instance.Software,
@@ -107,7 +214,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				UnavailableUntil = instance.UnavailableUntil is { } until ? MastodonJson.Time(until) : default,
 				LastSuccessAt = instance.LastSuccessAt is { } success ? MastodonJson.Time(success) : default,
 				LastFailureAt = instance.LastFailureAt is { } failure ? MastodonJson.Time(failure) : default
-			}
+			},
+			Geo = Located(PublicGeo.Project(instance.Geo), instance.Geo, beforeCdn)
 		};
 
 		public class Provenance
@@ -170,6 +278,48 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			public string DescriptionError { get; set; }
 			public JsonNode NodeInfo { get; set; }
 			public InstanceDelivery Delivery { get; set; }
+			public InstanceLocation Geo { get; set; }
+		}
+
+		//precision: "city" (coordinates to 0.1°, city and network), "country" (located only to a country) or "cdn" (the
+		//CDN's name only)
+		public class InstanceLocation
+		{
+			public string Precision { get; set; }
+			public string Country { get; set; }
+			public string City { get; set; }
+			public double? Latitude { get; set; }
+			public double? Longitude { get; set; }
+			public string Network { get; set; }
+			public string Cdn { get; set; }
+			public string CdnDomain { get; set; }
+			public string CdnSource { get; set; }//"ranges", "headers" or "asn"
+			public InstancePlace BeforeCdn { get; set; }//where a CDN-fronted server was located before the CDN, by its snapshots
+			public string Source { get; set; }
+			public string LocatedAt { get; set; }
+		}
+
+		public class InstancePlace
+		{
+			public string Week { get; set; }
+			public string Country { get; set; }
+			public string City { get; set; }
+			public double? Latitude { get; set; }
+			public double? Longitude { get; set; }
+		}
+
+		public class InstanceWeek
+		{
+			public string Week { get; set; }
+			public string TakenAt { get; set; }
+			public bool Reachable { get; set; }
+			public string Software { get; set; }
+			public string Version { get; set; }
+			public long? UsersTotal { get; set; }
+			public long? UsersActiveMonth { get; set; }
+			public long? LocalPosts { get; set; }
+			public bool? OpenRegistrations { get; set; }
+			public InstanceLocation Geo { get; set; }
 		}
 
 		public class InstanceDelivery

PrivaPub/Api/Mastodon/Controllers/ScheduledStatusesController.cs

@@ -0,0 +1,103 @@
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Domain.Media;
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Infrastructure.Jobs;
+using PrivaPub.Models.Media;
+using PrivaPub.Models.Social;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Mastodon's scheduled statuses (owner decision 2026-10-04, back from the cut list): the persona's posts waiting for
+	// their time, moved to another time or dropped. POST /api/v1/statuses with scheduled_at makes them.
+	public class ScheduledStatusesController : MastodonController
+	{
+		readonly IMediaService _media;
+		readonly IJobQueue _jobs;
+
+		public ScheduledStatusesController(IMediaService media, IJobQueue jobs)
+		{
+			_media = media;
+			_jobs = jobs;
+		}
+
+		public static async Task<object> View(ScheduledStatus scheduled, IMediaService media, CancellationToken token)
+		{
+			var p = scheduled.Params;
+			var ids = p.MediaIds;
+			var attachments = ids.Count == 0
+				? new List<MediaAttachment>()
+				: await DB.Default.Find<MediaAttachment>().Match(m => ids.Contains(m.ID)).ExecuteAsync(token);
+			return new
+			{
+				id = scheduled.ID,
+				scheduled_at = MastodonJson.Time(scheduled.ScheduledAt),
+				@params = new
+				{
+					text = p.Text,
+					poll = p.Poll == default ? default : new { options = p.Poll.Options, expires_in = p.Poll.ExpiresIn, multiple = p.Poll.Multiple, hide_totals = p.Poll.HideTotals },
+					media_ids = ids.Count == 0 ? default : ids,
+					sensitive = p.Sensitive,
+					spoiler_text = p.SpoilerText,
+					visibility = p.Visibility,
+					in_reply_to_id = p.InReplyToId,
+					language = p.Language,
+					application_id = default(string),
+					scheduled_at = default(string),
+					idempotency = p.Idempotency,
+					with_rate_limit = false,
+					quoted_status_id = p.QuotedStatusId
+				},
+				media_attachments = ids.Select(id => attachments.FirstOrDefault(m => m.ID == id)).Where(m => m != default)
+					.Select(m => MediaController.View(media, m)).ToList()
+			};
+		}
+
+		Task<ScheduledStatus> Mine(string id, CancellationToken token) =>
+			DB.Default.Find<ScheduledStatus>().Match(s => s.ID == id && s.AvatarId == MyId).ExecuteFirstAsync(token);
+
+		[HttpGet("/api/v1/scheduled_statuses"), Scope("read:statuses")]
+		public async Task<IActionResult> All(CancellationToken token)
+		{
+			var page = await Page.From(Params, Limit(20, 40)).Fetch(DB.Default.Find<ScheduledStatus>().Match(s => s.AvatarId == MyId), s => s.ID, token);
+			Link("/api/v1/scheduled_statuses", page.LastOrDefault()?.ID, page.FirstOrDefault()?.ID);
+			var views = new List<object>();
+			foreach (var scheduled in page)
+				views.Add(await View(scheduled, _media, token));
+			return Json(views);
+		}
+
+		[HttpGet("/api/v1/scheduled_statuses/{id}"), Scope("read:statuses")]
+		public async Task<IActionResult> One(string id, CancellationToken token) =>
+			await Mine(id, token) is { } scheduled ? Json(await View(scheduled, _media, token)) : NotFoundError();
+
+		[HttpPut("/api/v1/scheduled_statuses/{id}"), Scope("write:statuses")]
+		public async Task<IActionResult> Move(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } scheduled)
+				return NotFoundError();
+			if (!DateTime.TryParse(Params.Get("scheduled_at"), System.Globalization.CultureInfo.InvariantCulture,
+					System.Globalization.DateTimeStyles.AdjustToUniversal | System.Globalization.DateTimeStyles.AssumeUniversal, out var at))
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Scheduled at is invalid");
+			if (await ScheduledStatuses.Refusal(MyId, at, scheduled.ID, token) is { } refusal)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: " + refusal);
+			scheduled.ScheduledAt = at;
+			await DB.Default.Update<ScheduledStatus>().MatchID(scheduled.ID).Modify(s => s.ScheduledAt, at).ExecuteAsync(token);
+			await _jobs.EnqueueMany(new[] { ScheduledStatuses.JobFor(scheduled, new Uri(Me.BaseAddress).Host) }, token);
+			return Json(await View(scheduled, _media, token));
+		}
+
+		[HttpDelete("/api/v1/scheduled_statuses/{id}"), Scope("write:statuses")]
+		public async Task<IActionResult> Drop(string id, CancellationToken token)
+		{
+			if (await Mine(id, token) is not { } scheduled)
+				return NotFoundError();
+			await DB.Default.DeleteAsync<ScheduledStatus>(scheduled.ID);
+			await ScheduledStatuses.Release(scheduled.ID, token);
+			return Json(new { });
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/SearchController.cs

@@ -15,7 +15,7 @@ using PostEntity = PrivaPub.Models.Post.Post;
 
 namespace PrivaPub.Api.Mastodon.Controllers
 {
-	public class SearchController : MastodonController
+	public partial class SearchController : MastodonController
 	{
 		readonly MastodonMapper _mapper;
 		readonly DbEntities _dbEntities;
@@ -35,11 +35,15 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			_search = search;
 		}
 
-		[HttpGet("/api/v2/search"), Scope("read:search", requiresUser: false)]
+		// Anyone may search, as on Mastodon; only resolving (which fetches from other servers) and paging need a sign-in.
+		[HttpGet("/api/v2/search"), Scope("read:search", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Search(CancellationToken token)
 		{
 			var q = Params.Get("q")?.Trim();
 			var type = Params.Get("type");
+			var offset = Params.Int("offset") ?? 0;
+			if (MyId == default && (Params.Bool("resolve") == true || offset > 0))
+				return Error(StatusCodes.Status401Unauthorized, "Search queries that resolve uris or use offset require the read:search scope");
 			var resolve = Params.Bool("resolve") == true && MyId != default;
 			var results = new SearchResults();
 			if (string.IsNullOrEmpty(q))
@@ -51,7 +55,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				if (post == default && resolve && type is null or "statuses")
 					post = await _remotePosts.StoreContext(q, 0, token);
 				if (post != default && type is null or "statuses" && await VisibilityPolicy.CanSee(post, MyId, token))
-					results.Statuses.Add(await _mapper.Status(post, MyId, token));
+					if (await _mapper.Status(post, MyId, token) is { } status)
+						results.Statuses.Add(status);
 				if (results.Statuses.Count == 0 && type is null or "accounts")
 				{
 					var local = await _localActors.FindByUri(q, token);
@@ -66,61 +71,78 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 			if (type is null or "accounts")
 			{
-				results.Accounts = await _search.Find(q, resolve, Limit(), token);
+				results.Accounts = await _search.Find(q, resolve, Limit(), Math.Max(0, offset), token);
 			}
-			if (type is null or "hashtags" && q.TrimStart('#') is { Length: > 0 } tag)
+			// an account's handle asks for the account, never for posts that happen to share its words
-				results.Hashtags.Add(new { name = tag.ToLowerInvariant(), url = $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(tag.ToLowerInvariant())}", history = Array.Empty<object>() });
+			if (type is null or "statuses" && MyId != default && !q.StartsWith('#') && !Handle().IsMatch(q))
+				results.Statuses = await Words(q, Math.Max(0, offset), Limit(), token);
+			if (type is null or "hashtags" && TagsController.Normalise(q) is var tag && TagsController.IsHashtag(tag))
+				results.Hashtags.Add(new { name = tag, url = $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(tag)}", history = Array.Empty<object>() });
 			return Json(results);
 		}
 	}
 
+	public partial class SearchController
+	{
+		const int WordCandidates = 400;
+
+		[System.Text.RegularExpressions.GeneratedRegex(@"^@?[^\s@]+@[^\s@]+$|^@[^\s@]+$")]
+		private static partial System.Text.RegularExpressions.Regex Handle();
+
+		// Posts by their words, as Mastodon searches them: those the persona wrote, boosted, favourited, bookmarked or was
+		// named in, and public posts of authors who let themselves be indexed; newest first, what the persona may see only
+		async Task<List<Status>> Words(string q, int offset, int limit, CancellationToken token)
+		{
+			var candidates = await _dbEntities.Posts.Match(f => f.Text(q)).Match(p => !p.DeletedAt.HasValue && p.ReblogOfPostId == null && !p.AuthorGone)
+				.Sort(p => p.ID, MongoDB.Entities.Order.Descending).Limit(WordCandidates).ExecuteAsync(token);
+			if (candidates.Count == 0)
+				return new List<Status>();
+			var ids = candidates.Select(p => p.ID).ToList();
+			var mine = new HashSet<string>();
+			mine.UnionWith((await _dbEntities.Favourites.Match(f => f.AccountId == MyId && ids.Contains(f.PostId)).ExecuteAsync(token)).Select(f => f.PostId));
+			mine.UnionWith((await MongoDB.Entities.DB.Default.Find<Models.Social.Bookmark>().Match(b => b.AvatarId == MyId && ids.Contains(b.PostId)).ExecuteAsync(token))
+				.Select(b => b.PostId));
+			mine.UnionWith((await _dbEntities.Posts.Match(p => p.AuthorAccountId == MyId && ids.Contains(p.ReblogOfPostId) && !p.DeletedAt.HasValue).ExecuteAsync(token))
+				.Select(p => p.ReblogOfPostId));
+			var authors = candidates.Select(p => p.AuthorAccountId ?? p.GroupUserId).Where(a => a != default).Distinct().ToList();
+			var indexable = (await _dbEntities.Avatars.Match(a => authors.Contains(a.ID) && a.Settings.IsIndexable).ExecuteAsync(token)).Select(a => a.ID)
+				.Concat((await _dbEntities.ForeignAvatars.Match(f => authors.Contains(f.ID) && f.IsIndexable).ExecuteAsync(token)).Select(f => f.ID))
+				.ToHashSet();
+			var found = new List<PostEntity>();
+			foreach (var post in candidates)
+			{
+				var author = post.AuthorAccountId ?? post.GroupUserId;
+				var reachable = author == MyId && !post.IsFederatedCopy || mine.Contains(post.ID) || post.Mentions.Any(m => m.AccountId == MyId)
+					|| post.Visibility == PostVisibility.Public && indexable.Contains(author);
+				if (reachable && await VisibilityPolicy.CanSee(post, MyId, token))
+					found.Add(post);
+				if (found.Count >= offset + limit)
+					break;
+			}
+			return await _mapper.Statuses(found.Skip(offset).Take(limit).ToList(), MyId, token);
+		}
+	}
+
 	public class StubsController : MastodonController
 	{
 		[HttpGet("/api/v1/custom_emojis"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public IActionResult CustomEmojis() => Json(Array.Empty<object>());
 
-		[HttpGet("/api/v1/filters"), Scope("read:filters")]
-		public IActionResult FiltersV1() => Json(Array.Empty<object>());
-
-		[HttpGet("/api/v2/filters"), Scope("read:filters")]
-		public IActionResult FiltersV2() => Json(Array.Empty<object>());
-
-		[HttpGet("/api/v1/lists"), Scope("read:lists")]
-		public IActionResult Lists() => Json(Array.Empty<object>());
-
 		[HttpGet("/api/v1/announcements"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public IActionResult Announcements() => Json(Array.Empty<object>());
 
-		[HttpGet("/api/v1/trends"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult Trends() => Json(Array.Empty<object>());
-
-		[HttpGet("/api/v1/trends/tags"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult TrendTags() => Json(Array.Empty<object>());
-
-		[HttpGet("/api/v1/trends/statuses"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult TrendStatuses() => Json(Array.Empty<object>());
-
-		[HttpGet("/api/v1/trends/links"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult TrendLinks() => Json(Array.Empty<object>());
-
 		[HttpGet("/api/v1/suggestions"), Scope("read")]
 		public IActionResult SuggestionsV1() => Json(Array.Empty<object>());
 
 		[HttpGet("/api/v2/suggestions"), Scope("read")]
 		public IActionResult SuggestionsV2() => Json(Array.Empty<object>());
 
-		[HttpGet("/api/v1/followed_tags"), Scope("read:follows")]
-		public IActionResult FollowedTags() => Json(Array.Empty<object>());
-
 		[HttpGet("/api/v1/endorsements"), Scope("read:accounts")]
 		public IActionResult Endorsements() => Json(Array.Empty<object>());
 
 		[HttpGet("/api/v1/featured_tags"), Scope("read:accounts")]
 		public IActionResult FeaturedTags() => Json(Array.Empty<object>());
 
-		[HttpGet("/api/v1/scheduled_statuses"), Scope("read:statuses")]
-		public IActionResult ScheduledStatuses() => Json(Array.Empty<object>());
-
 		[HttpGet("/api/v1/preferences"), Scope("read:accounts")]
 		public IActionResult Preferences() => Json(new Dictionary<string, object>
 		{
@@ -133,5 +155,32 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		[HttpGet("/api/v1/push/subscription"), Scope("push")]
 		public IActionResult PushSubscription() => Error(StatusCodes.Status404NotFound, "Record not found");
+
+		// Routes Mastodon answers that we have nothing behind: an empty or default answer lets clients degrade, where a
+		// 404 breaks some of them (Mastodon invariant 5)
+		[HttpGet("/api/v1/timelines/link"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult LinkTimeline() => Json(Array.Empty<object>());
+
+		[HttpGet("/api/v1/accounts/{id}/identity_proofs"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult IdentityProofs(string id) => Json(Array.Empty<object>());
+
+		[HttpGet("/api/v1/instance/languages"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult Languages() => Json(InstanceController.LanguageCodes(HttpContext.RequestServices)
+			.Select(code => new { code, name = System.Globalization.CultureInfo.GetCultureInfo(code).EnglishName }));
+
+		[HttpGet("/api/v1/instance/translation_languages"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult TranslationLanguages() => Json(new { });
+
+		[HttpGet("/api/v1/instance/domain_blocks"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult InstanceDomainBlocks() => Json(Array.Empty<object>());
+
+		[HttpGet("/api/v1/instance/privacy_policy"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult PrivacyPolicy() => Json(new
+		{
+			updated_at = "2026-10-04T00:00:00.000Z",
+			content = "<p>One private login owns several public personas, and nobody but this server's admin can tell they belong "
+				+ "together. What a persona posts is shared as its visibility says; a located post never leaves this server. "
+				+ "Uploads lose their metadata. Statistics name servers, never people: see /stargazing.</p>"
+		});
 	}
 }

PrivaPub/Api/Mastodon/Controllers/StatusesController.cs

@@ -9,6 +9,7 @@ using PrivaPub.Api.Mastodon.Mappers;
 using PrivaPub.Domain.Privacy;
 using PrivaPub.Domain.Statuses;
 using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
 using PrivaPub.Models.User;
 using PrivaPub.Federation.Rendering;
 using PrivaPub.Federation.Outbox;
@@ -29,10 +30,20 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		readonly IMemoryCache _cache;
 		readonly IQuoteService _quotes;
 		readonly IOutboxPublisher _outbox;
+		readonly PrivaPub.Infrastructure.Jobs.IJobQueue _jobs;
+		readonly Domain.Media.IMediaService _media;
+
+		readonly IParticipations _participations;
+		readonly Federation.Actors.IWalls _walls;
 
 		public StatusesController(IStatusService statuses, MastodonMapper mapper, DbEntities dbEntities, IMemoryCache cache, IQuoteService quotes,
-			IOutboxPublisher outbox)
+			IOutboxPublisher outbox, PrivaPub.Infrastructure.Jobs.IJobQueue jobs, Domain.Media.IMediaService media, IParticipations participations = default,
+			Federation.Actors.IWalls walls = default)
 		{
+			_walls = walls;
+			_participations = participations;
+			_jobs = jobs;
+			_media = media;
 			_quotes = quotes;
 			_outbox = outbox;
 			_statuses = statuses;
@@ -52,23 +63,31 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				if (existing != default)
 					return Json(await _mapper.Status(existing, MyId, token));
 			}
-			var outcome = await _statuses.Publish(Me, new StatusDraft
+			var asked = new ScheduledParams
 			{
 				Text = Params.Get("status"),
-				PlainText = true,
 				SpoilerText = Params.Get("spoiler_text"),
 				Sensitive = Params.Bool("sensitive") ?? Me.Settings.DefaultSensitive,
-				Visibility = Visibility(Params.Get("visibility") ?? Me.Settings.DefaultVisibility),
+				Visibility = Params.Get("visibility") ?? Me.Settings.DefaultVisibility,
-				InReplyTo = Params.Get("in_reply_to_id"),
+				InReplyToId = Params.Get("in_reply_to_id"),
 				Language = Params.Get("language") ?? Me.Settings.DefaultLanguage,
-				MediaIds = Params.List("media_ids"),
+				MediaIds = Params.List("media_ids").ToList(),
 				QuotedStatusId = Params.Get("quoted_status_id"),
 				QuotePolicy = Params.Get("quote_approval_policy"),
+				Idempotency = string.IsNullOrEmpty(idempotency) ? default : idempotency,
 				Poll = Params.Has("poll[options]")
-					? new PollDraft(Params.List("poll[options]"), Params.Int("poll[expires_in]") ?? 0, Params.Bool("poll[multiple]") == true,
+					? new ScheduledPoll
-						Params.Bool("poll[hide_totals]") == true)
+					{
+						Options = Params.List("poll[options]").ToList(),
+						ExpiresIn = Params.Int("poll[expires_in]") ?? 0,
+						Multiple = Params.Bool("poll[multiple]") == true,
+						HideTotals = Params.Bool("poll[hide_totals]") == true
+					}
 					: default
-			}, token);
+			};
+			if (Params.Get("scheduled_at") is { Length: > 0 } scheduledAt)
+				return await Schedule(asked, scheduledAt, cacheKey, token);
+			var outcome = await _statuses.Publish(Me, ScheduledStatuses.Draft(asked), token);
 			if (!outcome.Ok)
 				return Error(outcome.Status, outcome.Error);
 			if (cacheKey != default)
@@ -76,6 +95,35 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return Json(await _mapper.Status(outcome.Post, MyId, token));
 		}
 
+		// scheduled_at: the post waits, as asked, for a PublishScheduled job at that time; what it would need then (words,
+		// media of the persona's own, not yet posted) is checked now
+		async Task<IActionResult> Schedule(ScheduledParams asked, string scheduledAt, string cacheKey, CancellationToken token)
+		{
+			if (cacheKey != default && _cache.TryGetValue(cacheKey + ":scheduled", out string earlier)
+				&& await DB.Default.Find<ScheduledStatus>().MatchID(earlier).ExecuteFirstAsync(token) is { } waiting)
+				return Json(await ScheduledStatusesController.View(waiting, _media, token));
+			if (!DateTime.TryParse(scheduledAt, System.Globalization.CultureInfo.InvariantCulture,
+					System.Globalization.DateTimeStyles.AdjustToUniversal | System.Globalization.DateTimeStyles.AssumeUniversal, out var at))
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Scheduled at is invalid");
+			if (await ScheduledStatuses.Refusal(MyId, at, default, token) is { } refusal)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: " + refusal);
+			if (string.IsNullOrWhiteSpace(asked.Text) && asked.MediaIds.Count == 0 && asked.Poll == default)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Text can't be blank");
+			var mediaIds = asked.MediaIds.Distinct().ToList();
+			if (mediaIds.Count > 4 || mediaIds.Count > 0 && await DB.Default.CountAsync<Models.Media.MediaAttachment>(
+					m => mediaIds.Contains(m.ID) && m.OwnerAvatarId == MyId && m.PostId == null && m.ScheduledStatusId == null, token) != mediaIds.Count)
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Media attachments are not yours, already posted or too many");
+
+			var scheduled = new ScheduledStatus { AvatarId = MyId, ScheduledAt = at, Params = asked };
+			await DB.Default.SaveAsync(scheduled, token);
+			if (mediaIds.Count > 0)
+				await DB.Default.Update<Models.Media.MediaAttachment>().Match(m => mediaIds.Contains(m.ID)).Modify(m => m.ScheduledStatusId, scheduled.ID).ExecuteAsync(token);
+			await _jobs.EnqueueMany(new[] { ScheduledStatuses.JobFor(scheduled, new Uri(Me.BaseAddress).Host) }, token);
+			if (cacheKey != default)
+				_cache.Set(cacheKey + ":scheduled", scheduled.ID, TimeSpan.FromHours(1));
+			return Json(await ScheduledStatusesController.View(scheduled, _media, token));
+		}
+
 		[HttpGet("/api/v1/statuses"), Scope("read:statuses", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Many(CancellationToken token)
 		{
@@ -92,7 +140,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		public async Task<IActionResult> Get(string id, CancellationToken token)
 		{
 			var post = await Visible(id, token);
-			return post == default ? NotFoundError() : Json(await _mapper.Status(post, MyId, token));
+			var status = post == default ? default : await _mapper.Status(post, MyId, token);
+			return status == default ? NotFoundError() : Json(status);
 		}
 
 		[HttpPut("/api/v1/statuses/{id}"), Scope("write:statuses")]
@@ -115,7 +164,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		{
 			var before = await _dbEntities.Posts.Match(p => p.ID == id && p.GroupUserId == MyId && !p.IsFederatedCopy && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
 			if (before == default)
-				return NotFoundError();
+				return await OffWall(id, token);
 			var status = await _mapper.Status(before, MyId, token);
 			var outcome = await _statuses.Remove(Me, id, token);
 			if (!outcome.Ok)
@@ -128,6 +177,20 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return Json(status);
 		}
 
+		// someone's post on the persona's wall (FEP-400e), taken off it: as on Smithereen, the owner of a wall deletes what is on it
+		async Task<IActionResult> OffWall(string id, CancellationToken token)
+		{
+			var walled = _walls == default
+				? default
+				: await _dbEntities.Posts.Match(p => p.ID == id && p.WallOwnerAccountId == MyId && p.IsFederatedCopy && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			if (walled == default)
+				return NotFoundError();
+			var status = await _mapper.Status(walled, MyId, token);
+			if (!await _walls.Remove(Me, walled, token))
+				return NotFoundError();
+			return Json(status);
+		}
+
 		[HttpGet("/api/v1/statuses/{id}/context"), Scope("read:statuses", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
 		public async Task<IActionResult> Context(string id, CancellationToken token)
 		{
@@ -160,6 +223,11 @@ namespace PrivaPub.Api.Mastodon.Controllers
 						frontier.Add(child.ID);
 					}
 			}
+			// a persona opening a public remote thread has its replies read from their servers, for the next look (once an hour)
+			if (MyId != default)
+				await _jobs.EnqueueMany(new[] { post, ancestors.FirstOrDefault() }
+					.Where(p => p is { IsFederatedCopy: true, Visibility: PostVisibility.Public or PostVisibility.Unlisted }).DistinctBy(p => p.ID)
+					.Select(p => Federation.Inbox.RepliesJobHandler.For(p, 1)), token);
 			return Json(new Context
 			{
 				Ancestors = await _mapper.Statuses(ancestors, MyId, token),
@@ -200,6 +268,22 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return post == default ? NotFoundError() : Json(new StatusSource { Id = post.ID, Text = post.Text ?? string.Empty, SpoilerText = post.SpoilerText ?? string.Empty });
 		}
 
+		// a persona joins or leaves a remote event (owner decision 2026-10-05); the status says how it stands
+		// (privapub.event.participation)
+		[HttpPost("/api/privapub/v1/statuses/{id}/join"), Scope("write:statuses")]
+		public async Task<IActionResult> Join(string id, CancellationToken token)
+		{
+			var outcome = await _participations.Join(Me, id, token);
+			return outcome.Ok ? Json(await _mapper.Status(outcome.Post, MyId, token)) : Error(outcome.Status, outcome.Error);
+		}
+
+		[HttpPost("/api/privapub/v1/statuses/{id}/leave"), Scope("write:statuses")]
+		public async Task<IActionResult> Leave(string id, CancellationToken token)
+		{
+			var outcome = await _participations.Leave(Me, id, token);
+			return outcome.Ok ? Json(await _mapper.Status(outcome.Post, MyId, token)) : Error(outcome.Status, outcome.Error);
+		}
+
 		[HttpPost("/api/v1/statuses/{id}/favourite"), Scope("write:favourites")]
 		public Task<IActionResult> Favourite(string id, CancellationToken token) => Toggle(_statuses.Favourite(Me, id, true, token), id, token);
 
@@ -338,6 +422,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			try
 			{
 				await DB.Default.SaveAsync(new Models.Social.Pin { AvatarId = MyId, PostId = post.ID }, token);
+				await _outbox.PublishFeatured(MyId, post, featured: true, token);
 			}
 			catch (MongoDB.Driver.MongoWriteException ex) when (ex.WriteError?.Category == MongoDB.Driver.ServerErrorCategory.DuplicateKey)
 			{
@@ -348,7 +433,9 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		[HttpPost("/api/v1/statuses/{id}/unpin"), Scope("write:accounts")]
 		public async Task<IActionResult> Unpin(string id, CancellationToken token)
 		{
-			await DB.Default.DeleteAsync<Models.Social.Pin>(p => p.AvatarId == MyId && p.PostId == id);
+			var unpinned = await DB.Default.DeleteAsync<Models.Social.Pin>(p => p.AvatarId == MyId && p.PostId == id);
+			if (unpinned is { IsAcknowledged: true, DeletedCount: > 0 } && await _dbEntities.Posts.MatchID(id).ExecuteFirstAsync(token) is { } post)
+				await _outbox.PublishFeatured(MyId, post, featured: false, token);
 			return await Unchanged(id, token);
 		}
 
@@ -364,7 +451,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		async Task<IActionResult> Unchanged(string id, CancellationToken token)
 		{
 			var post = await Visible(id, token);
-			return post == default ? NotFoundError() : Json(await _mapper.Status(post, MyId, token));
+			var status = post == default ? default : await _mapper.Status(post, MyId, token);
+			return status == default ? NotFoundError() : Json(status);
 		}
 
 		async Task<PostEntity> Visible(string id, CancellationToken token)
@@ -373,12 +461,6 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return post != default && post.Visibility != PostVisibility.LocalGeo && await VisibilityPolicy.CanSee(post, MyId, token) ? post : default;
 		}
 
-		static PostVisibility Visibility(string value) => value?.ToLowerInvariant() switch
+		static PostVisibility Visibility(string value) => ScheduledStatuses.Visibility(value);
-		{
-			"unlisted" => PostVisibility.Unlisted,
-			"private" => PostVisibility.FollowersOnly,
-			"direct" => PostVisibility.Direct,
-			_ => PostVisibility.Public
-		};
 	}
 }

PrivaPub/Api/Mastodon/Controllers/StreamingController.cs

@@ -0,0 +1,223 @@
+using System.Net.WebSockets;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Domain.Privacy;
+using PrivaPub.Domain.Timelines;
+using PrivaPub.Models.Social;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Mastodon's streaming API: one WebSocket on /api/v1/streaming that subscribes to streams by message, or one stream
+	// per request as server-sent events on /api/v1/streaming/{stream}. Every stream needs a signed-in persona (the token
+	// comes as access_token, in the Authorization header, or as the WebSocket's protocol). What a stream tells is mapped
+	// for that persona as it is sent: a post it may not see, or whose author it blocked or muted, is never sent.
+	public class StreamingController : MastodonController
+	{
+		static readonly TimeSpan KeepAlive = TimeSpan.FromSeconds(15);
+
+		readonly MastodonMapper _mapper;
+		readonly DbEntities _dbEntities;
+
+		public StreamingController(MastodonMapper mapper, DbEntities dbEntities)
+		{
+			_mapper = mapper;
+			_dbEntities = dbEntities;
+		}
+
+		[HttpGet("/api/v1/streaming/health"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public IActionResult Health() => Content("OK", "text/plain");
+
+		// the stream a name and its parameter make, or why not: a hashtag needs its tag, a list must be the persona's own
+		async Task<(Streams.Key Key, string Error)> Resolve(string name, string tag, string list, CancellationToken token)
+		{
+			switch (name)
+			{
+				case Streams.User or Streams.UserNotification or Streams.Public or Streams.PublicLocal or Streams.PublicRemote:
+					return (new Streams.Key(name), default);
+				case Streams.Hashtag or Streams.HashtagLocal:
+					var normal = TagsController.Normalise(tag);
+					return normal.Length == 0 ? (default, "Missing tag name parameter") : (new Streams.Key(name, normal), default);
+				case Streams.List:
+					return !string.IsNullOrEmpty(list) && await DB.Default.Find<PersonaList>().Match(l => l.ID == list && l.AvatarId == MyId).ExecuteAnyAsync(token)
+						? (new Streams.Key(name, list), default)
+						: (default, "Unknown list");
+				default:
+					return (default, "Unknown stream type");
+			}
+		}
+
+		// what the event says, for this persona: a status or a notification as JSON, a deleted id as itself; null when it
+		// is not the persona's to see
+		async Task<string> Payload(Streams.Event e, CancellationToken token)
+		{
+			if (e.Name == "delete")
+				return e.Id;
+			if (e.Name == "notification")
+			{
+				var notification = await _dbEntities.Notifications.Match(n => n.ID == e.Id && n.AvatarId == MyId).ExecuteFirstAsync(token);
+				var mapped = notification == default ? default : (await _mapper.Notifications(new List<Notification> { notification }, MyId, token)).FirstOrDefault();
+				return mapped == default ? default : JsonSerializer.Serialize(mapped, MastodonJson.Options);
+			}
+			var post = await _dbEntities.Posts.MatchID(e.Id).ExecuteFirstAsync(token);
+			if (post == default || !await VisibilityPolicy.CanSee(post, MyId, token))
+				return default;
+			var status = (await _mapper.Statuses(new[] { post }, MyId, token)).FirstOrDefault();
+			return status == default ? default : JsonSerializer.Serialize(status, MastodonJson.Options);
+		}
+
+		[HttpGet("/api/v1/streaming"), Scope("read")]
+		public async Task<IActionResult> Socket(CancellationToken token)
+		{
+			if (!HttpContext.WebSockets.IsWebSocketRequest)
+				return Error(StatusCodes.Status400BadRequest, "This is a WebSocket endpoint; server-sent events are at /api/v1/streaming/{stream}");
+			var protocol = HttpContext.WebSockets.WebSocketRequestedProtocols.FirstOrDefault();
+			using var socket = await HttpContext.WebSockets.AcceptWebSocketAsync(protocol);
+			var listener = Streams.Open(MyId);
+			var sending = new SemaphoreSlim(1, 1);
+			async Task Send(JsonObject message)
+			{
+				var bytes = Encoding.UTF8.GetBytes(message.ToJsonString());
+				await sending.WaitAsync(token);
+				try
+				{
+					await socket.SendAsync(bytes, WebSocketMessageType.Text, true, token);
+				}
+				finally
+				{
+					sending.Release();
+				}
+			}
+			async Task Subscribe(string type, string name, string tag, string list)
+			{
+				var (key, error) = await Resolve(name, tag, list, token);
+				if (error != default)
+				{
+					await Send(new JsonObject { ["error"] = error, ["status"] = 400 });
+					return;
+				}
+				if (type == "unsubscribe")
+					listener.Stop(key);
+				else
+					listener.Listen(key);
+			}
+			try
+			{
+				if (Params.Get("stream") is { Length: > 0 } first)
+					await Subscribe("subscribe", first, Params.Get("tag"), Params.Get("list"));
+				using var done = CancellationTokenSource.CreateLinkedTokenSource(token);
+				var reading = Task.Run(async () =>
+				{
+					var buffer = new byte[4096];
+					while (socket.State == WebSocketState.Open && !done.IsCancellationRequested)
+					{
+						var text = new StringBuilder();
+						WebSocketReceiveResult received;
+						do
+						{
+							received = await socket.ReceiveAsync(buffer, done.Token);
+							if (received.MessageType == WebSocketMessageType.Close)
+							{
+								done.Cancel();
+								return;
+							}
+							text.Append(Encoding.UTF8.GetString(buffer, 0, received.Count));
+						}
+						while (!received.EndOfMessage && text.Length < 16384);
+						JsonNode message;
+						try
+						{
+							message = JsonNode.Parse(text.ToString());
+						}
+						catch (JsonException)
+						{
+							continue;
+						}
+						if (message?["type"]?.GetValue<string>() is "subscribe" or "unsubscribe" && message["stream"]?.GetValue<string>() is { } stream)
+							await Subscribe(message["type"]!.GetValue<string>(), stream, message["tag"]?.GetValue<string>(), message["list"]?.GetValue<string>());
+					}
+				}, done.Token);
+				await foreach (var (key, e) in listener.Queue.Reader.ReadAllAsync(done.Token))
+				{
+					if (!listener.Hears(key) || await Payload(e, done.Token) is not { } payload)
+						continue;
+					await Send(new JsonObject { ["stream"] = new JsonArray(key.Wire.Select(w => (JsonNode)w).ToArray()), ["event"] = e.Name, ["payload"] = payload });
+				}
+				await reading;
+			}
+			catch (Exception ex) when (ex is OperationCanceledException or WebSocketException)
+			{
+			}
+			finally
+			{
+				Streams.Close(listener);
+				if (socket.State == WebSocketState.Open)
+					await socket.CloseAsync(WebSocketCloseStatus.NormalClosure, default, CancellationToken.None);
+			}
+			return new EmptyResult();
+		}
+
+		[HttpGet("/api/v1/streaming/{*stream}"), Scope("read")]
+		public async Task<IActionResult> Events(string stream, CancellationToken token)
+		{
+			var name = stream.Replace('/', ':');
+			var (key, error) = await Resolve(name, Params.Get("tag"), Params.Get("list"), token);
+			if (error != default)
+				return Error(StatusCodes.Status400BadRequest, error);
+			Response.ContentType = "text/event-stream";
+			Response.Headers.CacheControl = "no-cache";
+			Response.Headers["X-Accel-Buffering"] = "no";
+			var listener = Streams.Open(MyId);
+			listener.Listen(key);
+			var writing = new SemaphoreSlim(1, 1);
+			async Task Write(string text)
+			{
+				await writing.WaitAsync(token);
+				try
+				{
+					await Response.WriteAsync(text, token);
+					await Response.Body.FlushAsync(token);
+				}
+				finally
+				{
+					writing.Release();
+				}
+			}
+			try
+			{
+				await Write(":)\n\n");
+				var beating = Task.Run(async () =>
+				{
+					while (!token.IsCancellationRequested)
+					{
+						await Task.Delay(KeepAlive, token);
+						await Write(":thump\n\n");
+					}
+				}, token);
+				await foreach (var (_, e) in listener.Queue.Reader.ReadAllAsync(token))
+				{
+					if (await Payload(e, token) is not { } payload)
+						continue;
+					await Write($"event: {e.Name}\ndata: {payload}\n\n");
+				}
+				await beating;
+			}
+			catch (OperationCanceledException)
+			{
+			}
+			finally
+			{
+				Streams.Close(listener);
+			}
+			return new EmptyResult();
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/TagsController.cs

@@ -0,0 +1,116 @@
+using System.Text;
+
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Federation.Actors;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Hashtags as Mastodon shows them (owner decision 2026-10-04, followed tags back from the cut list): a tag with the
+	// last week of its use in public posts PrivaPub holds, and whether the persona follows it; following one brings its
+	// public posts to the persona's home as they arrive (Fanout).
+	public class TagsController : MastodonController
+	{
+		const int MaxFollowed = 500;
+
+		readonly DbEntities _dbEntities;
+		readonly ILocalActorService _localActors;
+
+		public TagsController(DbEntities dbEntities, ILocalActorService localActors)
+		{
+			_dbEntities = dbEntities;
+			_localActors = localActors;
+		}
+
+		public static string Normalise(string name) => name?.Trim().TrimStart('#').Normalize(NormalizationForm.FormKC).ToLowerInvariant() ?? string.Empty;
+
+		// what a hashtag can be, as Mastodon has it: letters, marks, digits and underscores, with a letter or underscore
+		public static bool IsHashtag(string normal) =>
+			normal.Length is > 0 and <= 100 && normal.All(c => char.IsLetterOrDigit(c) || c == '_' || char.GetUnicodeCategory(c) is
+				System.Globalization.UnicodeCategory.NonSpacingMark or System.Globalization.UnicodeCategory.SpacingCombiningMark)
+			&& normal.Any(c => char.IsLetter(c) || c == '_');
+
+		// a day's uses and authors, newest first, for the last week, as Mastodon gives them (strings, days as unix time)
+		public static async Task<List<object>> History(DbEntities dbEntities, string tag, CancellationToken token)
+		{
+			var today = DateTime.UtcNow.Date;
+			var since = today.AddDays(-6);
+			var posts = await dbEntities.Posts
+				.Match(p => p.Tags.Contains(tag) && p.Visibility == PostVisibility.Public && !p.DeletedAt.HasValue && p.CreationDate >= since)
+				.Project(p => p.Include(x => x.CreationDate).Include(x => x.AuthorAccountId).Include(x => x.GroupUserId))
+				.ExecuteAsync(token);
+			return Enumerable.Range(0, 7).Select(back => today.AddDays(-back)).Select(day =>
+			{
+				var that = posts.Where(p => p.CreationDate >= day && p.CreationDate < day.AddDays(1)).ToList();
+				return (object)new
+				{
+					day = new DateTimeOffset(day, TimeSpan.Zero).ToUnixTimeSeconds().ToString(),
+					uses = that.Count.ToString(),
+					accounts = that.Select(p => p.AuthorAccountId ?? p.GroupUserId).Distinct().Count().ToString()
+				};
+			}).ToList();
+		}
+
+		async Task<object> View(string tag, bool? following, CancellationToken token) => new
+		{
+			name = tag,
+			url = $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(tag)}",
+			history = await History(_dbEntities, tag, token),
+			following = following ?? (MyId != default && await DB.Default.Find<FollowedTag>().Match(t => t.AvatarId == MyId && t.Name == tag).ExecuteAnyAsync(token))
+		};
+
+		[HttpGet("/api/v1/tags/{name}"), Scope("read", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public async Task<IActionResult> Tag(string name, CancellationToken token)
+		{
+			var tag = Normalise(name);
+			return tag.Length == 0 ? NotFoundError() : Json(await View(tag, default, token));
+		}
+
+		[HttpPost("/api/v1/tags/{name}/follow"), Scope("write:follows")]
+		public async Task<IActionResult> Follow(string name, CancellationToken token)
+		{
+			var tag = Normalise(name);
+			if (tag.Length == 0 || tag.Length > 100)
+				return NotFoundError();
+			if (!await DB.Default.Find<FollowedTag>().Match(t => t.AvatarId == MyId && t.Name == tag).ExecuteAnyAsync(token))
+			{
+				if (await DB.Default.CountAsync<FollowedTag>(t => t.AvatarId == MyId, token) >= MaxFollowed)
+					return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Too many followed hashtags");
+				try
+				{
+					await DB.Default.SaveAsync(new FollowedTag { AvatarId = MyId, Name = tag }, token);
+				}
+				catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
+				{
+				}
+			}
+			return Json(await View(tag, true, token));
+		}
+
+		[HttpPost("/api/v1/tags/{name}/unfollow"), Scope("write:follows")]
+		public async Task<IActionResult> Unfollow(string name, CancellationToken token)
+		{
+			var tag = Normalise(name);
+			await DB.Default.DeleteAsync<FollowedTag>(t => t.AvatarId == MyId && t.Name == tag);
+			return Json(await View(tag, false, token));
+		}
+
+		[HttpGet("/api/v1/followed_tags"), Scope("read:follows")]
+		public async Task<IActionResult> Followed(CancellationToken token)
+		{
+			var page = await Page.From(Params, Limit(100, 200)).Fetch(DB.Default.Find<FollowedTag>().Match(t => t.AvatarId == MyId), t => t.ID, token);
+			Link("/api/v1/followed_tags", page.LastOrDefault()?.ID, page.FirstOrDefault()?.ID);
+			var views = new List<object>();
+			foreach (var followed in page)
+				views.Add(await View(followed.Name, true, token));
+			return Json(views);
+		}
+	}
+}

PrivaPub/Api/Mastodon/Controllers/TimelinesController.cs

@@ -1,11 +1,14 @@
 using Microsoft.AspNetCore.Mvc;
 
+using MongoDB.Driver;
 using MongoDB.Entities;
 
 using PrivaPub.Api.Mastodon.Entities;
 using PrivaPub.Api.Mastodon.Infrastructure;
 using PrivaPub.Api.Mastodon.Mappers;
 using PrivaPub.Domain.Privacy;
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Models.Group;
 using PrivaPub.Models.Post;
 using PrivaPub.Models.Social;
 using PrivaPub.StaticServices;
@@ -30,7 +33,15 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		[HttpGet("/api/v1/timelines/home"), Scope("read:statuses")]
 		public async Task<IActionResult> Home(CancellationToken token)
 		{
-			var entries = await Page.From(Params, Limit()).Fetch(_dbEntities.TimelineEntries.Match(e => e.AvatarId == MyId), e => e.PostId, token);
+			//an exclusive list's members are read in that list, not at home
+			var exclusive = (await DB.Default.Find<PersonaList>().Match(l => l.AvatarId == MyId && l.Exclusive).ExecuteAsync(token)).Select(l => l.ID).ToList();
+			var apart = exclusive.Count == 0
+				? new List<string>()
+				: (await DB.Default.Find<PersonaListMember>().Match(m => exclusive.Contains(m.ListId)).ExecuteAsync(token)).Select(m => m.AccountId).Distinct().ToList();
+			var home = _dbEntities.TimelineEntries.Match(e => e.AvatarId == MyId);
+			if (apart.Count > 0)
+				home.Match(e => !apart.Contains(e.AuthorAccountId));
+			var entries = await Page.From(Params, Limit()).Fetch(home, 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 statuses = await _mapper.Statuses(ids.Where(posts.ContainsKey).Select(id => posts[id]).ToList(), MyId, token);
@@ -61,9 +72,6 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return await Respond(query, $"/api/v1/timelines/tag/{hashtag}", token);
 		}
 
-		[HttpGet("/api/v1/timelines/list/{id}"), Scope("read:lists")]
-		public IActionResult List(string id) => Json(Array.Empty<Status>());
-
 		[HttpGet("/api/v1/favourites"), Scope("read:favourites")]
 		public async Task<IActionResult> Favourites(CancellationToken token)
 		{
@@ -78,41 +86,79 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return Json(await _mapper.Statuses(visible, MyId, token));
 		}
 
+		// the persona's direct conversations, by their newest post (paged like Mastodon's by that post's id), each with its
+		// other members and whether its newest post, someone else's, is newer than what the persona read; the ones it took
+		// off its list stay off until a newer message
 		[HttpGet("/api/v1/conversations"), Scope("read:statuses")]
 		public async Task<IActionResult> Conversations(CancellationToken token)
 		{
-			var groups = await _dbEntities.DmGroups.Match(g => !g.DeletionAt.HasValue && g.Members.Any(m => !m.IsForeign && m.AvatarId == MyId))
+			var groups = await Page.From(Params, Limit(20, 40)).Fetch(
-				.Sort(g => g.UpdatedAt, Order.Descending).Limit(Limit()).ExecuteAsync(token);
+				_dbEntities.DmGroups.Match(g => !g.DeletionAt.HasValue && g.LastPostId != null && g.Members.Any(m => !m.IsForeign && m.AvatarId == MyId)),
-			var conversations = new List<Conversation>();
+				g => g.LastPostId, token);
-			foreach (var group in groups)
+			Link("/api/v1/conversations", groups.LastOrDefault()?.LastPostId, groups.FirstOrDefault()?.LastPostId);
-			{
+			return Json(await ConversationsOf(groups, token));
-				var last = await _dbEntities.Posts.Match(p => p.ConversationId == group.ID).Match(VisibilityPolicy.IsShown).Sort(p => p.ID, Order.Descending).ExecuteFirstAsync(token);
-				if (last == default)
-					continue;
-				var others = new List<string>();
-				foreach (var member in group.Members.Where(m => !(m.AvatarId == MyId && !m.IsForeign)))
-					others.Add(member.IsForeign
-						? (await _dbEntities.ForeignAvatars.Match(f => f.ActorURI == member.AvatarId).ExecuteFirstAsync(token))?.ID
-						: member.AvatarId);
-				var accounts = await _mapper.Accounts(others, token);
-				conversations.Add(new Conversation
-				{
-					Id = group.ID,
-					Accounts = accounts.Values.ToList(),
-					LastStatus = await _mapper.Status(last, MyId, token)
-				});
 		}
-			return Json(conversations);
+
+		async Task<List<Conversation>> ConversationsOf(List<DmGroup> groups, CancellationToken token)
+		{
+			var ids = groups.Select(g => g.ID).ToList();
+			var states = (await DB.Default.Find<ConversationState>().Match(s => s.AvatarId == MyId && ids.Contains(s.ConversationId)).ExecuteAsync(token))
+				.ToDictionary(s => s.ConversationId);
+			groups = groups.Where(g => !ConversationStates.IsHidden(states.GetValueOrDefault(g.ID), g.LastPostId)).ToList();
+
+			// the newest post each conversation still shows: usually its LastPostId, else (deleted) the one before
+			var newestIds = groups.Select(g => g.LastPostId).ToList();
+			var newest = (await _dbEntities.Posts.Match(p => newestIds.Contains(p.ID)).Match(VisibilityPolicy.IsShown).ExecuteAsync(token))
+				.ToDictionary(p => p.ConversationId);
+			foreach (var group in groups.Where(g => !newest.ContainsKey(g.ID)))
+				if (await _dbEntities.Posts.Match(p => p.ConversationId == group.ID).Match(VisibilityPolicy.IsShown).Sort(p => p.ID, Order.Descending)
+					.ExecuteFirstAsync(token) is { } shown)
+					newest[group.ID] = shown;
+
+			var foreignUris = groups.SelectMany(g => g.Members).Where(m => m.IsForeign).Select(m => m.AvatarId).Distinct().ToList();
+			var foreignIds = (await _dbEntities.ForeignAvatars.Match(f => foreignUris.Contains(f.ActorURI)).ExecuteAsync(token))
+				.GroupBy(f => f.ActorURI).ToDictionary(g => g.Key, g => g.First().ID);
+			List<string> Others(DmGroup group) => group.Members.Where(m => !(m.AvatarId == MyId && !m.IsForeign))
+				.Select(m => m.IsForeign ? foreignIds.GetValueOrDefault(m.AvatarId) : m.AvatarId).Where(id => id != default).ToList();
+			var accounts = await _mapper.Accounts(groups.SelectMany(Others).Distinct(), token);
+			var statuses = (await _mapper.Statuses(newest.Values.ToList(), MyId, token)).ToDictionary(s => s.Id);
+
+			return groups.Where(g => newest.ContainsKey(g.ID) && statuses.ContainsKey(newest[g.ID].ID))
+				.Select(g => new Conversation
+				{
+					Id = g.ID,
+					Unread = ConversationStates.IsUnread(states.GetValueOrDefault(g.ID), newest[g.ID].ID, newest[g.ID].AuthorAccountId, MyId),
+					Accounts = Others(g).Select(id => accounts.GetValueOrDefault(id)).Where(a => a != default).ToList(),
+					LastStatus = statuses[newest[g.ID].ID]
+				})
+				.ToList();
 		}
 
+		async Task<DmGroup> MyConversation(string id, CancellationToken token) =>
+			await _dbEntities.DmGroups.Match(g => g.ID == id && !g.DeletionAt.HasValue && g.Members.Any(m => !m.IsForeign && m.AvatarId == MyId))
+				.ExecuteFirstAsync(token);
+
 		[HttpPost("/api/v1/conversations/{id}/read"), Scope("write:conversations")]
 		public async Task<IActionResult> ReadConversation(string id, CancellationToken token)
 		{
-			var group = await _dbEntities.DmGroups.Match(g => g.ID == id && g.Members.Any(m => !m.IsForeign && m.AvatarId == MyId)).ExecuteFirstAsync(token);
+			var group = await MyConversation(id, token);
 			if (group == default)
 				return NotFoundError();
-			var last = await _dbEntities.Posts.Match(p => p.ConversationId == group.ID).Match(VisibilityPolicy.IsShown).Sort(p => p.ID, Order.Descending).ExecuteFirstAsync(token);
+			await ConversationStates.Read(MyId, group.ID, group.LastPostId, token);
-			return Json(new Conversation { Id = group.ID, LastStatus = last == default ? default : await _mapper.Status(last, MyId, token) });
+			var conversation = (await ConversationsOf(new List<DmGroup> { group }, token)).FirstOrDefault();
+			return Json(conversation ?? new Conversation { Id = group.ID });
+		}
+
+		// off the persona's list until a newer message; the messages themselves stay
+		[HttpDelete("/api/v1/conversations/{id}"), Scope("write:conversations")]
+		public async Task<IActionResult> RemoveConversation(string id, CancellationToken token)
+		{
+			var group = await MyConversation(id, token);
+			if (group == default)
+				return NotFoundError();
+			await ConversationStates.Hide(MyId, group.ID, group.LastPostId, token);
+			await ConversationStates.Read(MyId, group.ID, group.LastPostId, token);
+			return Json(new { });
 		}
 
 		[HttpGet("/api/v1/markers"), Scope("read:statuses")]
@@ -141,6 +187,10 @@ namespace PrivaPub.Api.Mastodon.Controllers
 					.Option(o => o.IsUpsert = true)
 					.ExecuteAsync(token);
 				result[timeline] = new Entities.Marker { LastReadId = marker.LastReadId, Version = marker.Version, UpdatedAt = MastodonJson.Time(marker.UpdatedAt) };
+				// what the marker passes is read: the unread count (v1 and v2) counts only what is newer
+				if (timeline == "notifications")
+					await DB.Default.Update<NotificationEntity>().Match(n => n.AvatarId == MyId && !n.IsRead)
+						.Match(f => f.Lte(n => n.ID, lastRead)).Modify(n => n.IsRead, true).ExecuteAsync(token);
 			}
 			return Json(result);
 		}
@@ -155,7 +205,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 	public class NotificationsController : MastodonController
 	{
-		static readonly Dictionary<NotificationType, string> Names = new()
+		internal static readonly Dictionary<NotificationType, string> Names = new()
 		{
 			[NotificationType.Mention] = "mention",
 			[NotificationType.Follow] = "follow",
@@ -177,23 +227,150 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			_dbEntities = dbEntities;
 		}
 
-		[HttpGet("/api/v1/notifications"), Scope("read:notifications")]
+		Find<NotificationEntity, NotificationEntity> Filtered()
-		public async Task<IActionResult> List(CancellationToken token)
 		{
 			var types = Params.List("types").Select(Parse).Where(t => t.HasValue).Select(t => t.Value).ToList();
 			var excluded = Params.List("exclude_types").Select(Parse).Where(t => t.HasValue).Select(t => t.Value).ToList();
 			var query = _dbEntities.Notifications.Match(n => n.AvatarId == MyId);
+			// what the persona's notification policy filtered stays in its requests, unless asked for (a request's own page)
+			if (Params.Bool("include_filtered") != true)
+				query.Match(NotFiltered);
 			if (types.Count > 0)
 				query.Match(n => types.Contains(n.Type));
 			if (excluded.Count > 0)
 				query.Match(n => !excluded.Contains(n.Type));
 			if (Params.Get("account_id") is { } accountId)
 				query.Match(n => n.FromAccountId == accountId);
-			var notifications = await Page.From(Params, Limit(15, 30)).Fetch(query, n => n.ID, token);
+			return query;
+		}
+
+		// (notifications made before the policy have no Filtered at all)
+		static readonly FilterDefinition<NotificationEntity> NotFiltered = Builders<NotificationEntity>.Filter.Ne(n => n.Filtered, true);
+
+		[HttpGet("/api/v1/notifications"), Scope("read:notifications")]
+		public async Task<IActionResult> List(CancellationToken token)
+		{
+			var notifications = await Page.From(Params, Limit(15, 30)).Fetch(Filtered(), n => n.ID, token);
 			Link("/api/v1/notifications", notifications.LastOrDefault()?.ID, notifications.FirstOrDefault()?.ID);
 			return Json(await Map(notifications, token));
 		}
 
+		// Grouped notifications (Mastodon 4.3): api_versions.mastodon says we speak that API, so clients call it. Likes and
+		// boosts of one post group together, as do follows within an hour; everything else stands alone.
+		internal static readonly HashSet<string> DefaultGrouped = new() { "favourite", "reblog", "follow" };
+
+		HashSet<string> Grouped() => Params.List("grouped_types") is { Count: > 0 } chosen ? chosen.ToHashSet() : DefaultGrouped;
+
+		internal static string GroupKey(NotificationEntity n, ISet<string> grouped) =>
+			!grouped.Contains(Names[n.Type]) ? $"ungrouped-{n.ID}"
+			: n.Type == NotificationType.Follow ? $"grouped-follow-{n.CreatedAt:yyyyMMddHH}"
+			: string.IsNullOrEmpty(n.PostId) ? $"ungrouped-{n.ID}"
+			: $"grouped-{Names[n.Type]}-{n.PostId}";
+
+		// the notifications a group key stands for
+		System.Linq.Expressions.Expression<Func<NotificationEntity, bool>> InGroup(string key)
+		{
+			var me = MyId;
+			if (key.StartsWith("ungrouped-", StringComparison.Ordinal))
+			{
+				var id = key["ungrouped-".Length..];
+				return n => n.AvatarId == me && n.ID == id;
+			}
+			if (key.StartsWith("grouped-follow-", StringComparison.Ordinal)
+				&& DateTime.TryParseExact(key["grouped-follow-".Length..], "yyyyMMddHH", System.Globalization.CultureInfo.InvariantCulture,
+					System.Globalization.DateTimeStyles.AdjustToUniversal | System.Globalization.DateTimeStyles.AssumeUniversal, out var hour))
+			{
+				var end = hour.AddHours(1);
+				return n => n.AvatarId == me && n.Type == NotificationType.Follow && n.CreatedAt >= hour && n.CreatedAt < end;
+			}
+			if (key.Split('-') is ["grouped", var name, var postId] && Parse(name) is { } type)
+				return n => n.AvatarId == me && n.Type == type && n.PostId == postId;
+			return default;
+		}
+
+		async Task<List<NotificationEntity>> Members(string key, CancellationToken token) =>
+			InGroup(key) is { } filter
+				? await _dbEntities.Notifications.Match(filter).Match(NotFiltered).Sort(n => n.ID, Order.Descending).Limit(80).ExecuteAsync(token)
+				: new List<NotificationEntity>();
+
+		async Task<object> Groups(List<NotificationEntity> page, ISet<string> grouped, CancellationToken token)
+		{
+			var mapped = (await Map(page, token)).ToDictionary(n => n.Id);
+			var shown = page.Where(n => mapped.ContainsKey(n.ID)).ToList();
+			var groups = new List<object>();
+			foreach (var group in shown.GroupBy(n => GroupKey(n, grouped)))
+			{
+				var newest = mapped[group.First().ID];
+				var total = group.Key.StartsWith("ungrouped-", StringComparison.Ordinal) ? 1
+					: await DB.Default.CountAsync(Builders<NotificationEntity>.Filter.And(Builders<NotificationEntity>.Filter.Where(InGroup(group.Key)), NotFiltered), token);
+				groups.Add(new
+				{
+					group_key = group.Key,
+					notifications_count = Math.Max(total, group.Count()),
+					type = newest.Type,
+					most_recent_notification_id = newest.Id,
+					page_min_id = group.Last().ID,
+					page_max_id = group.First().ID,
+					latest_page_notification_at = newest.CreatedAt,
+					sample_account_ids = group.Select(n => mapped[n.ID].Account.Id).Distinct().Take(8).ToList(),
+					status_id = newest.Status?.Id,
+					emoji = newest.Emoji,
+					emoji_url = newest.EmojiUrl
+				});
+			}
+			return new
+			{
+				accounts = mapped.Values.Select(n => n.Account).DistinctBy(a => a.Id).ToList(),
+				statuses = mapped.Values.Where(n => n.Status != default).Select(n => n.Status).DistinctBy(s => s.Id).ToList(),
+				notification_groups = groups
+			};
+		}
+
+		[HttpGet("/api/v2/notifications"), Scope("read:notifications")]
+		public async Task<IActionResult> GroupedList(CancellationToken token)
+		{
+			var notifications = await Page.From(Params, Limit(40, 80)).Fetch(Filtered(), n => n.ID, token);
+			Link("/api/v2/notifications", notifications.LastOrDefault()?.ID, notifications.FirstOrDefault()?.ID);
+			return Json(await Groups(notifications, Grouped(), token));
+		}
+
+		[HttpGet("/api/v2/notifications/unread_count"), Scope("read:notifications")]
+		public async Task<IActionResult> GroupedUnreadCount(CancellationToken token)
+		{
+			var unread = await Filtered().Match(n => !n.IsRead).Sort(n => n.ID, Order.Descending)
+				.Limit(Math.Clamp(Params.Int("limit") ?? 100, 1, 1000)).ExecuteAsync(token);
+			var shown = (await Map(unread, token)).Select(n => n.Id).ToHashSet();
+			var grouped = Grouped();
+			return Json(new { count = unread.Where(n => shown.Contains(n.ID)).Select(n => GroupKey(n, grouped)).Distinct().Count() });
+		}
+
+		[HttpGet("/api/v2/notifications/{groupKey}"), Scope("read:notifications")]
+		public async Task<IActionResult> Group(string groupKey, CancellationToken token)
+		{
+			var members = await Members(groupKey, token);
+			if (members.Count == 0)
+				return NotFoundError();
+			return Json(await Groups(members, new HashSet<string>(DefaultGrouped.Append(Names[members[0].Type])), token));
+		}
+
+		[HttpGet("/api/v2/notifications/{groupKey}/accounts"), Scope("read:notifications")]
+		public async Task<IActionResult> GroupAccounts(string groupKey, CancellationToken token)
+		{
+			var members = await Members(groupKey, token);
+			if (members.Count == 0)
+				return NotFoundError();
+			return Json((await Map(members, token)).Select(n => n.Account).DistinctBy(a => a.Id).ToList());
+		}
+
+		[HttpPost("/api/v2/notifications/{groupKey}/dismiss"), Scope("write:notifications")]
+		public async Task<IActionResult> DismissGroup(string groupKey, CancellationToken token)
+		{
+			if (InGroup(groupKey) is not { } filter)
+				return NotFoundError();
+			await DB.Default.DeleteAsync(filter);
+			return Json(new { });
+		}
+
 		[HttpGet("/api/v1/notifications/{id}"), Scope("read:notifications")]
 		public async Task<IActionResult> Get(string id, CancellationToken token)
 		{
@@ -216,34 +393,19 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return Json(new { });
 		}
 
+		// counts what the list would show (Map drops notifications from gone accounts and about hidden posts), at most
+		// `limit` of them, as Mastodon does
 		[HttpGet("/api/v1/notifications/unread_count"), Scope("read:notifications")]
-		public async Task<IActionResult> UnreadCount(CancellationToken token) =>
+		public async Task<IActionResult> UnreadCount(CancellationToken token)
-			Json(new { count = await DB.Default.CountAsync<NotificationEntity>(n => n.AvatarId == MyId && !n.IsRead, token) });
-
-		async Task<List<Entities.Notification>> Map(List<NotificationEntity> notifications, CancellationToken token)
 		{
-			var accounts = await _mapper.Accounts(notifications.Select(n => n.FromAccountId), token);
+			var unread = await DB.Default.Find<NotificationEntity>().Match(n => n.AvatarId == MyId && !n.IsRead).Match(NotFiltered)
-			var postIds = notifications.Where(n => n.PostId != default).Select(n => n.PostId).Distinct().ToList();
+				.Sort(n => n.ID, Order.Descending).Limit(Math.Clamp(Params.Int("limit") ?? 100, 1, 1000)).ExecuteAsync(token);
-			var posts = postIds.Count == 0
+			return Json(new { count = (await Map(unread, token)).Count });
-				? new List<PostEntity>()
-				: await _dbEntities.Posts.Match(p => postIds.Contains(p.ID)).Match(VisibilityPolicy.IsShown).ExecuteAsync(token);
-			var statuses = (await _mapper.Statuses(posts, MyId, token)).ToDictionary(s => s.Id);
-			return notifications
-				.Where(n => accounts.ContainsKey(n.FromAccountId ?? string.Empty) && (n.PostId == default || statuses.ContainsKey(n.PostId)))
-				.Select(n => new Entities.Notification
-				{
-					Id = n.ID,
-					Type = Names[n.Type],
-					CreatedAt = MastodonJson.Time(n.CreatedAt),
-					GroupKey = $"ungrouped-{n.ID}",
-					Account = accounts[n.FromAccountId],
-					Status = n.PostId == default ? default : statuses[n.PostId],
-					Emoji = n.Emoji == default ? default : n.EmojiURL == default ? n.Emoji : $":{n.Emoji}:",
-					EmojiUrl = _mapper.ProxiedUrl(n.EmojiURL)
-				})
-				.ToList();
 		}
 
+		Task<List<Entities.Notification>> Map(List<NotificationEntity> notifications, CancellationToken token) =>
+			_mapper.Notifications(notifications, MyId, token);
+
 		static NotificationType? Parse(string name) => Names.FirstOrDefault(n => n.Value == name) is { Value: not null } pair ? pair.Key : (NotificationType?)null;
 	}
 }

PrivaPub/Api/Mastodon/Controllers/TrendsController.cs

@@ -0,0 +1,160 @@
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Infrastructure;
+using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Domain.Privacy;
+using PrivaPub.Domain.Social;
+using PrivaPub.Federation.Actors;
+using PrivaPub.Models.User;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Api.Mastodon.Controllers
+{
+	// Trends and the directory (owner decision 2026-10-04, back from the cut list), from what PrivaPub already holds
+	// (Trends). The directory lists only accounts that let themselves be discovered.
+	public class TrendsController : MastodonController
+	{
+		readonly Trends _trends;
+		readonly MastodonMapper _mapper;
+		readonly DbEntities _dbEntities;
+		readonly ILocalActorService _localActors;
+
+		public TrendsController(Trends trends, MastodonMapper mapper, DbEntities dbEntities, ILocalActorService localActors)
+		{
+			_trends = trends;
+			_mapper = mapper;
+			_dbEntities = dbEntities;
+			_localActors = localActors;
+		}
+
+		static List<object> History(Trends.Trend trend) => trend.History.Select(h => (object)new
+		{
+			day = new DateTimeOffset(h.Day, TimeSpan.Zero).ToUnixTimeSeconds().ToString(),
+			uses = h.Uses.ToString(),
+			accounts = h.Accounts.ToString()
+		}).ToList();
+
+		IEnumerable<T> Window<T>(IEnumerable<T> items, int fallback, int max) =>
+			items.Skip(Math.Max(0, Params.Int("offset") ?? 0)).Take(Limit(fallback, max));
+
+		[HttpGet("/api/v1/trends"), HttpGet("/api/v1/trends/tags"), Scope("read", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public async Task<IActionResult> Tags(CancellationToken token)
+		{
+			var followed = MyId == default
+				? new HashSet<string>()
+				: (await DB.Default.Find<Models.Social.FollowedTag>().Match(t => t.AvatarId == MyId).ExecuteAsync(token)).Select(t => t.Name).ToHashSet();
+			return Json(Window(await _trends.Tags(token), 10, 20).Select(t => new
+			{
+				name = t.Key,
+				url = $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(t.Key)}",
+				history = History(t),
+				following = MyId == default ? default(bool?) : followed.Contains(t.Key)
+			}).ToList());
+		}
+
+		[HttpGet("/api/v1/trends/statuses"), Scope("read", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public async Task<IActionResult> Statuses(CancellationToken token)
+		{
+			var ids = Window(await _trends.Statuses(token), 20, 40).ToList();
+			var posts = (await _dbEntities.Posts.Match(p => ids.Contains(p.ID)).Match(VisibilityPolicy.IsShown).ExecuteAsync(token)).ToDictionary(p => p.ID);
+			return Json(await _mapper.Statuses(ids.Where(posts.ContainsKey).Select(id => posts[id]).ToList(), MyId, token));
+		}
+
+		[HttpGet("/api/v1/trends/links"), Scope("read", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public async Task<IActionResult> Links(CancellationToken token)
+		{
+			var trends = Window(await _trends.Links(token), 10, 20).ToList();
+			var sampleIds = trends.Select(t => t.SamplePostId).ToList();
+			var samples = (await _dbEntities.Posts.Match(p => sampleIds.Contains(p.ID)).ExecuteAsync(token)).ToDictionary(p => p.ID);
+			return Json(trends.Where(t => samples.ContainsKey(t.SamplePostId)).Select(t =>
+			{
+				var link = samples[t.SamplePostId].Link;
+				var card = _mapper.LinkCard(t.Key, link.Title, link.Description, link.ImageURL);
+				return card == default ? default : (object)new
+				{
+					card.Url, card.Title, card.Description, card.Type, card.AuthorName, card.AuthorUrl, card.ProviderName, card.ProviderUrl,
+					card.Html, card.Width, card.Height, card.Image, card.ImageDescription, card.EmbedUrl, card.Blurhash, card.Language,
+					card.PublishedAt, card.Authors, History = History(t)
+				};
+			}).Where(c => c != default).ToList());
+		}
+
+		// order=active: by their latest public post PrivaPub holds; order=new: by when they say they joined, which for a
+		// persona is its published day (never its creation, so personas made together are not told apart by their order)
+		[HttpGet("/api/v1/directory"), Scope("read", requiresUser: false), Microsoft.AspNetCore.Authorization.AllowAnonymous]
+		public async Task<IActionResult> Directory(CancellationToken token)
+		{
+			var offset = Math.Max(0, Params.Int("offset") ?? 0);
+			var limit = Limit(40, 80);
+			var localOnly = Params.Bool("local") == true;
+			var barred = await Counted.BarredPersonas(token);
+			var wanted = offset + limit;
+			var ordered = new List<string>();
+			if (Params.Get("order") == "new")
+			{
+				// many share a day: the first `wanted` are read with every other of the last one's day, so each page is cut the same way
+				var personas = await _dbEntities.Avatars.Match(a => a.Settings.IsDiscoverable && !a.DeletionAt.HasValue && !barred.Contains(a.ID))
+					.Sort(a => a.PublishedOn, Order.Descending).Limit(wanted).ExecuteAsync(token);
+				if (personas.Count == wanted)
+				{
+					var edge = personas[^1].PublishedOn;
+					var known = personas.Select(a => a.ID).ToList();
+					personas.AddRange(await _dbEntities.Avatars.Match(a => a.Settings.IsDiscoverable && !a.DeletionAt.HasValue && !barred.Contains(a.ID)
+						&& a.PublishedOn == edge && !known.Contains(a.ID)).ExecuteAsync(token));
+				}
+				var remote = localOnly
+					? new List<ForeignAvatar>()
+					: await _dbEntities.ForeignAvatars.Match(f => f.IsDiscoverable && !f.DeletionAt.HasValue && !f.SuspendedAt.HasValue && f.Published != null)
+						.Sort(f => f.Published, Order.Descending).Limit(wanted).ExecuteAsync(token);
+				if (remote.Count == wanted)
+				{
+					var edge = remote[^1].Published;
+					var known = remote.Select(f => f.ID).ToList();
+					remote.AddRange(await _dbEntities.ForeignAvatars.Match(f => f.IsDiscoverable && !f.DeletionAt.HasValue && !f.SuspendedAt.HasValue
+						&& f.Published == edge && !known.Contains(f.ID)).ExecuteAsync(token));
+				}
+				ordered = personas.Select(a => (a.ID, Joined: a.PublishedOn, Tie: Tie(a.UserName)))
+					.Concat(remote.Select(f => (f.ID, Joined: f.Published.Value, Tie: Tie(f.ActorURI))))
+					.OrderByDescending(a => a.Joined).ThenBy(a => a.Tie, StringComparer.Ordinal)
+					.Select(a => a.ID).Skip(offset).Take(limit).ToList();
+			}
+			else
+			{
+				var discoverableLocal = (await _dbEntities.Avatars.Match(a => a.Settings.IsDiscoverable && !a.DeletionAt.HasValue && !barred.Contains(a.ID))
+					.Project(a => a.Include(x => x.ID)).ExecuteAsync(token)).Select(a => a.ID).ToHashSet();
+				var seen = new HashSet<string>();
+				var maxId = default(string);
+				for (var round = 0; round < 20 && ordered.Count < wanted; round++)
+				{
+					var page = _dbEntities.Posts.Match(p => p.Visibility == Models.Post.PostVisibility.Public && !p.DeletedAt.HasValue && p.ReblogOfPostId == null);
+					if (maxId != default)
+						page.Match(f => f.Lt(p => p.ID, maxId));
+					if (localOnly)
+						page.Match(p => !p.IsFederatedCopy);
+					var batch = await page.Sort(p => p.ID, Order.Descending).Limit(500)
+						.Project(p => p.Include(x => x.ID).Include(x => x.AuthorAccountId).Include(x => x.GroupUserId).Include(x => x.IsFederatedCopy))
+						.ExecuteAsync(token);
+					if (batch.Count == 0)
+						break;
+					maxId = batch[^1].ID;
+					var fresh = batch.Select(p => (Id: p.AuthorAccountId ?? p.GroupUserId, p.IsFederatedCopy)).Where(a => a.Id != default && seen.Add(a.Id)).ToList();
+					var remoteIds = fresh.Where(a => a.IsFederatedCopy).Select(a => a.Id).ToList();
+					var discoverableRemote = remoteIds.Count == 0
+						? new HashSet<string>()
+						: (await _dbEntities.ForeignAvatars.Match(f => remoteIds.Contains(f.ID) && f.IsDiscoverable && !f.DeletionAt.HasValue && !f.SuspendedAt.HasValue)
+							.Project(f => f.Include(x => x.ID)).ExecuteAsync(token)).Select(f => f.ID).ToHashSet();
+					ordered.AddRange(fresh.Where(a => a.IsFederatedCopy ? discoverableRemote.Contains(a.Id) : discoverableLocal.Contains(a.Id)).Select(a => a.Id));
+				}
+				ordered = ordered.Skip(offset).Take(limit).ToList();
+			}
+			var accounts = await _mapper.Accounts(ordered, token);
+			return Json(ordered.Where(accounts.ContainsKey).Select(id => accounts[id]).ToList());
+		}
+
+		static string Tie(string name) =>
+			Convert.ToHexString(System.Security.Cryptography.SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(name ?? string.Empty)));
+	}
+}

PrivaPub/Api/Mastodon/Entities/Entities.cs

@@ -1,4 +1,4 @@
-namespace PrivaPub.Api.Mastodon.Entities
+namespace PrivaPub.Api.Mastodon.Entities
 {
 	public class Account
 	{
@@ -32,6 +32,7 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public string HeaderDescription { get; set; } = string.Empty;
 		public List<Field> Fields { get; set; } = new();
 		public Source Source { get; set; }
+		public Account Moved { get; set; }//the account it moved to, when that account names it among its aliases
 	}
 
 	public class CustomEmojiEntity
@@ -65,6 +66,8 @@ namespace PrivaPub.Api.Mastodon.Entities
 	public class PrivaPubStatus
 	{
 		public string ObjectType { get; set; }
+		public bool Locked { get; set; }//its community's moderators locked it: a reply is refused
+		public string Approval { get; set; }//our reply or boost its target's author must approve: "pending", "rejected"
 		public string Title { get; set; }
 		public string Excerpt { get; set; }
 		public string Cover { get; set; }
@@ -73,6 +76,8 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public PrivaPubVideo Video { get; set; }
 		public PrivaPubAudio Audio { get; set; }
 		public PrivaPubEvent Event { get; set; }
+		public PrivaPubPlace Place { get; set; }//a remote post's own place (Pixelfed), shown only
+		public Account Wall { get; set; }//whose wall it was written on (FEP-400e), when not its author's
 		public PrivaPubVotes Votes { get; set; } = new();
 	}
 
@@ -145,12 +150,14 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public int? Capacity { get; set; }
 		public string Status { get; set; }
 		public string Category { get; set; }
+		public string Participation { get; set; }//the viewer's: "pending", "accepted" or "rejected"
 	}
 
 	public class PrivaPubPlace
 	{
 		public string Name { get; set; }
 		public string Address { get; set; }
+		public string Country { get; set; }//a post's own place only
 		public double? Latitude { get; set; }
 		public double? Longitude { get; set; }
 		public string Url { get; set; }
@@ -176,6 +183,48 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public string CurrentUser { get; set; } = "denied";
 	}
 
+	public class FilterEntity
+	{
+		public string Id { get; set; }
+		public string Title { get; set; }
+		public List<string> Context { get; set; } = new();
+		public string ExpiresAt { get; set; }
+		public string FilterAction { get; set; }
+		public List<FilterKeywordEntity> Keywords { get; set; } = new();
+		public List<FilterStatusEntity> Statuses { get; set; } = new();
+	}
+
+	public class FilterKeywordEntity
+	{
+		public string Id { get; set; }
+		public string Keyword { get; set; }
+		public bool WholeWord { get; set; }
+	}
+
+	public class FilterStatusEntity
+	{
+		public string Id { get; set; }
+		public string StatusId { get; set; }
+	}
+
+	public class FilterResultEntity
+	{
+		public FilterEntity Filter { get; set; }
+		public List<string> KeywordMatches { get; set; }
+		public List<string> StatusMatches { get; set; }
+	}
+
+	// the v1 filter, which is one keyword of a v2 filter
+	public class FilterV1Entity
+	{
+		public string Id { get; set; }
+		public string Phrase { get; set; }
+		public List<string> Context { get; set; } = new();
+		public bool WholeWord { get; set; }
+		public string ExpiresAt { get; set; }
+		public bool Irreversible { get; set; }
+	}
+
 	public class EmojiReactionEntity
 	{
 		public string Name { get; set; }
@@ -264,13 +313,28 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public Application Application { get; set; }
 		public string Language { get; set; }
 		public string Text { get; set; }
-		public List<object> Filtered { get; set; } = new();
+		public List<FilterResultEntity> Filtered { get; set; } = new();
 		public PrivaPubStatus Privapub { get; set; }
 		public List<EmojiReactionEntity> EmojiReactions { get; set; } = new();
 		public PleromaStatus Pleroma { get; set; }
 		public QuoteEntity Quote { get; set; }
 		public int QuotesCount { get; set; }
 		public QuoteApprovalEntity QuoteApproval { get; set; }
+		public InteractionPolicyEntity InteractionPolicy { get; set; }//GoToSocial's: who may like, reply to and boost a remote post
+	}
+
+	// GoToSocial's interaction_policy: "public", "followers", "following", "author", "me", or an account's URI
+	public class InteractionPolicyEntity
+	{
+		public InteractionRuleEntity CanFavourite { get; set; }
+		public InteractionRuleEntity CanReply { get; set; }
+		public InteractionRuleEntity CanReblog { get; set; }
+	}
+
+	public class InteractionRuleEntity
+	{
+		public List<string> AutomaticApproval { get; set; } = new();
+		public List<string> ManualApproval { get; set; } = new();
 	}
 
 	public class MediaAttachment

PrivaPub/Api/Mastodon/Infrastructure/MastodonParams.cs

@@ -8,14 +8,19 @@ namespace PrivaPub.Api.Mastodon.Infrastructure
 	{
 		readonly Dictionary<string, List<string>> _values;
 
-		MastodonParams(Dictionary<string, List<string>> values)
+		MastodonParams(Dictionary<string, List<string>> values, JsonElement? json = default)
 		{
 			_values = values;
+			Json = json;
 		}
 
+		// a JSON body as it came, for what flattening loses: which fields belong to the same object of an array
+		public JsonElement? Json { get; }
+
 		public static async Task<MastodonParams> Read(HttpRequest request, CancellationToken token)
 		{
 			var values = new Dictionary<string, List<string>>(StringComparer.Ordinal);
+			JsonElement? json = default;
 			foreach (var pair in request.Query)
 				foreach (var value in pair.Value)
 					Add(values, pair.Key, value);
@@ -33,12 +38,13 @@ namespace PrivaPub.Api.Mastodon.Infrastructure
 				{
 					using var document = await JsonDocument.ParseAsync(request.Body, cancellationToken: token);
 					Flatten(values, default, document.RootElement);
+					json = document.RootElement.Clone();
 				}
 				catch (JsonException)
 				{
 				}
 			}
-			return new MastodonParams(values);
+			return new MastodonParams(values, json);
 		}
 
 		public static MastodonParams From(IEnumerable<KeyValuePair<string, string>> pairs)
@@ -51,6 +57,8 @@ namespace PrivaPub.Api.Mastodon.Infrastructure
 
 		public bool Has(string name) => _values.ContainsKey(name);
 
+		public IEnumerable<string> Names => _values.Keys;
+
 		public string Get(string name) => _values.TryGetValue(name, out var list) && list.Count > 0 ? list[^1] : default;
 
 		public IReadOnlyList<string> List(string name) => _values.TryGetValue(name, out var list) ? list : (IReadOnlyList<string>)Array.Empty<string>();

PrivaPub/Api/Mastodon/Mappers/AccountSearch.cs

@@ -19,7 +19,34 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			_remoteActors = remoteActors;
 		}
 
-		public async Task<List<Account>> Find(string q, bool resolve, int limit, CancellationToken token)
+		public async Task<List<Account>> Find(string q, bool resolve, int limit, CancellationToken token) => await Find(q, resolve, limit, 0, token);
+
+		// following=true: only accounts the persona follows, matched by the start of their name, display name or server
+		// (what a client offers when adding to a list), read from what PrivaPub holds and never resolved
+		public async Task<List<Account>> Followed(string viewerId, string q, int limit, CancellationToken token)
+		{
+			q = q?.Trim().TrimStart('@') ?? string.Empty;
+			var ids = (await _dbEntities.Followings.Match(f => f.AvatarId == viewerId && f.State == Models.Social.FollowState.Accepted).ExecuteAsync(token))
+				.Select(f => f.TargetAccountId).Where(id => !string.IsNullOrEmpty(id)).ToList();
+			if (ids.Count == 0)
+				return new List<Account>();
+			var parts = q.Split('@');
+			var localDomain = new Uri(_localActors.BaseAddress).Authority;
+			bool Matches(string userName, string name, string domain) =>
+				userName?.StartsWith(parts[0], StringComparison.OrdinalIgnoreCase) == true
+					&& (parts.Length < 2 || domain?.StartsWith(parts[1], StringComparison.OrdinalIgnoreCase) == true)
+				|| parts.Length == 1 && name?.Contains(q, StringComparison.OrdinalIgnoreCase) == true;
+			var found = (await _dbEntities.Avatars.Match(a => ids.Contains(a.ID) && !a.DeletionAt.HasValue).ExecuteAsync(token))
+				.Where(a => Matches(a.UserName, a.Name, localDomain)).Select(a => (a.UserName, a.ID))
+				.Concat((await _dbEntities.ForeignAvatars.Match(f => ids.Contains(f.ID) && !f.DeletionAt.HasValue).ExecuteAsync(token))
+					.Where(f => Matches(f.UserName, f.Name, f.Domain)).Select(f => (f.UserName, f.ID)))
+				.OrderBy(a => a.UserName, StringComparer.OrdinalIgnoreCase).Take(limit).Select(a => a.ID).ToList();
+			var accounts = await _mapper.Accounts(found, token);
+			return found.Where(accounts.ContainsKey).Select(id => accounts[id]).ToList();
+		}
+
+		// gone accounts (remote ones that deleted themselves, personas of banned or deleted roots) are never found
+		public async Task<List<Account>> Find(string q, bool resolve, int limit, int offset, CancellationToken token)
 		{
 			q = q?.Trim().TrimStart('@');
 			if (string.IsNullOrEmpty(q))
@@ -31,23 +58,30 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			{
 				var userName = parts[0];
 				var domain = parts[1].ToLowerInvariant();
-				var known = await _dbEntities.ForeignAvatars.Match(f => f.UserName == userName && f.Domain == domain).ExecuteFirstAsync(token);
+				var known = await _dbEntities.ForeignAvatars.Match(f => f.UserName == userName && f.Domain == domain && !f.DeletionAt.HasValue).ExecuteFirstAsync(token);
 				if (known == default && resolve)
 				{
 					var actorUri = await _remoteActors.ResolveHandle(q, token);
 					known = actorUri == default ? default : await _remoteActors.GetActor(actorUri, refresh: false, token);
 				}
-				if (known != default)
+				if (known is { DeletionAt: null } && offset == 0)
 					results.Add(_mapper.Foreign(known));
 				return results;
 			}
 
 			var prefix = parts[0].ToLowerInvariant();
-			foreach (var avatar in await _dbEntities.Avatars.Match(a => a.UserName.StartsWith(prefix) && !a.DeletionAt.HasValue && a.Settings.IsDiscoverable != false)
+			var barred = await Domain.Privacy.Counted.BarredPersonas(token);
-				.Limit(limit).ExecuteAsync(token))
+			var locals = await _dbEntities.Avatars
+				.Match(a => a.UserName.StartsWith(prefix) && !a.DeletionAt.HasValue && a.Settings.IsDiscoverable != false && !barred.Contains(a.ID))
+				.Sort(a => a.UserName, MongoDB.Entities.Order.Ascending)
+				.Limit(offset + limit).ExecuteAsync(token);
+			foreach (var avatar in locals.Skip(offset))
 				results.Add(await _mapper.Local(_localActors.FromAvatar(avatar), false, token));
-			foreach (var foreign in await _dbEntities.ForeignAvatars.Match(f => f.UserName.StartsWith(parts[0]) && f.IsDiscoverable)
+			var skipRemote = Math.Max(0, offset - locals.Count);
-				.Limit(Math.Max(0, limit - results.Count)).ExecuteAsync(token))
+			if (results.Count < limit)
+				foreach (var foreign in await _dbEntities.ForeignAvatars.Match(f => f.UserName.StartsWith(parts[0]) && f.IsDiscoverable && !f.DeletionAt.HasValue)
+					.Sort(f => f.UserName, MongoDB.Entities.Order.Ascending)
+					.Skip(skipRemote).Limit(limit - results.Count).ExecuteAsync(token))
 					results.Add(_mapper.Foreign(foreign));
 			return results;
 		}

PrivaPub/Api/Mastodon/Mappers/MastodonMapper.cs

@@ -1,4 +1,4 @@
-using MongoDB.Entities;
+using MongoDB.Entities;
 
 using PrivaPub.Api.Mastodon.Entities;
 using PrivaPub.Api.Mastodon.Infrastructure;
@@ -40,6 +40,32 @@ namespace PrivaPub.Api.Mastodon.Mappers
 
 		public string ProxiedUrl(string url) => Proxied(url);
 
+		// notifications as the persona sees them: one whose account or post it can no longer see is left out
+		public async Task<List<Entities.Notification>> Notifications(List<Models.Social.Notification> notifications, string viewerId, CancellationToken token)
+		{
+			var accounts = await Accounts(notifications.Select(n => n.FromAccountId), token);
+			var postIds = notifications.Where(n => n.PostId != default).Select(n => n.PostId).Distinct().ToList();
+			var posts = postIds.Count == 0
+				? new List<PostEntity>()
+				: await _dbEntities.Posts.Match(p => postIds.Contains(p.ID)).Match(VisibilityPolicy.IsShown).ExecuteAsync(token);
+			var statuses = (await Statuses(posts, viewerId, token)).ToDictionary(s => s.Id);
+			return notifications
+				.Where(n => accounts.ContainsKey(n.FromAccountId ?? string.Empty) && (n.PostId == default || statuses.ContainsKey(n.PostId)))
+				.Select(n => new Entities.Notification
+				{
+					Id = n.ID,
+					Type = Controllers.NotificationsController.Names[n.Type],
+					CreatedAt = MastodonJson.Time(n.CreatedAt),
+					//the group it belongs to by default, so a notification told alone (v1, a stream) joins its group in a client
+					GroupKey = Controllers.NotificationsController.GroupKey(n, Controllers.NotificationsController.DefaultGrouped),
+					Account = accounts[n.FromAccountId],
+					Status = n.PostId == default ? default : statuses[n.PostId],
+					Emoji = n.Emoji == default ? default : n.EmojiURL == default ? n.Emoji : $":{n.Emoji}:",
+					EmojiUrl = Proxied(n.EmojiURL)
+				})
+				.ToList();
+		}
+
 		string MissingAvatar => $"{_localActors.BaseAddress}/media/missing-avatar.png";
 		string MissingHeader => $"{_localActors.BaseAddress}/media/missing-header.png";
 
@@ -50,15 +76,11 @@ namespace PrivaPub.Api.Mastodon.Mappers
 				? await DB.Default.CountAsync<Following>(f => f.AvatarId == actor.Id && f.State == FollowState.Accepted, token)
 				: 0;
 			var latest = await _dbEntities.Posts
-				.Match(p => (actor.Kind == LocalActorKind.Group ? p.GroupId == actor.Id : p.GroupUserId == actor.Id) && !p.IsFederatedCopy
+				.Match(Counted.By(actor))
-					&& !p.DeletedAt.HasValue && p.Visibility != PostVisibility.Direct && p.ReblogOfPostId == null)
 				.Sort(p => p.ID, Order.Descending)
 				.Limit(1)
 				.ExecuteFirstAsync(token);
-			var statuses = latest == default
+			var statuses = latest == default ? 0 : await Counted.PostsBy(actor, token);
-				? 0
-				: await DB.Default.CountAsync<PostEntity>(p => (actor.Kind == LocalActorKind.Group ? p.GroupId == actor.Id : p.GroupUserId == actor.Id)
-					&& !p.IsFederatedCopy && !p.DeletedAt.HasValue && p.Visibility != PostVisibility.Direct && p.ReblogOfPostId == null, token);
 
 			var account = new Account
 			{
@@ -71,7 +93,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 				Discoverable = actor.Discoverable,
 				Indexable = actor.Indexable,
 				Noindex = !actor.Indexable,
-				HideCollections = actor.Settings.HideCollections,
+				HideCollections = true,//follower and following lists are never shown to others, only their counts
 				Group = actor.Kind == LocalActorKind.Group,
 				CreatedAt = MastodonJson.Day(actor.Published),
 				Note = ActivityPubRenderer.Html(actor.Summary),
@@ -124,7 +146,10 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			Avatar = Proxied(foreign.PictureURL) ?? MissingAvatar,
 			AvatarStatic = Proxied(foreign.PictureURL) ?? MissingAvatar,
 			Header = Proxied(foreign.ThumbnailURL) ?? MissingHeader,
-			HeaderStatic = Proxied(foreign.ThumbnailURL) ?? MissingHeader
+			HeaderStatic = Proxied(foreign.ThumbnailURL) ?? MissingHeader,
+			FollowersCount = foreign.FollowersCount ?? 0,//as its server publishes them (AccountCountsJob); 0 while unknown
+			FollowingCount = foreign.FollowingCount ?? 0,
+			StatusesCount = foreign.StatusesCount ?? 0
 		};
 
 		public async Task<Account> Account(string id, CancellationToken token) =>
@@ -141,18 +166,32 @@ namespace PrivaPub.Api.Mastodon.Mappers
 				accounts[avatar.ID] = await Local(_localActors.FromAvatar(avatar), false, token);
 			foreach (var group in await _dbEntities.Groups.Match(g => wanted.Contains(g.ID) && !g.DeletionAt.HasValue && g.Kind == GroupKind.Community).ExecuteAsync(token))
 				accounts[group.ID] = await Local(_localActors.FromGroup(group), false, token);
-			foreach (var foreign in await _dbEntities.ForeignAvatars.Match(f => wanted.Contains(f.ID)).ExecuteAsync(token))
+			var foreigns = await _dbEntities.ForeignAvatars.Match(f => wanted.Contains(f.ID) && !f.DeletionAt.HasValue).ExecuteAsync(token);
+			foreach (var foreign in foreigns)
 				accounts[foreign.ID] = Foreign(foreign);
+			// an account that moved shows where to, once the new account names it as one of its own (as a Move is believed)
+			var movedTo = foreigns.Where(f => !string.IsNullOrEmpty(f.MovedToURL)).Select(f => f.MovedToURL).Distinct().ToList();
+			if (movedTo.Count > 0)
+			{
+				var targets = (await _dbEntities.ForeignAvatars.Match(f => movedTo.Contains(f.ActorURI) && !f.DeletionAt.HasValue).ExecuteAsync(token))
+					.ToDictionary(f => f.ActorURI);
+				foreach (var foreign in foreigns)
+					if (foreign.MovedToURL != default && targets.TryGetValue(foreign.MovedToURL, out var target) && target.AlsoKnownAs.Contains(foreign.ActorURI))
+						accounts[foreign.ID].Moved = Foreign(target);
+			}
 			return accounts;
 		}
 
 		public async Task<Status> Status(PostEntity post, string viewerId, CancellationToken token) =>
-			(await Statuses(new[] { post }, viewerId, token)).FirstOrDefault();
+			(await Statuses(new[] { post }, viewerId, nested: false, token, hideFromViewer: false)).FirstOrDefault();
 
 		public Task<List<Status>> Statuses(IReadOnlyCollection<PostEntity> posts, string viewerId, CancellationToken token) =>
 			Statuses(posts, viewerId, nested: false, token);
 
-		async Task<List<Status>> Statuses(IReadOnlyCollection<PostEntity> posts, string viewerId, bool nested, CancellationToken token)
+		// Lists leave out what the viewer blocked or muted; a status asked for by its id is still shown, as Mastodon shows it
+		// (only its author's block of the viewer hides it, and that is decided before mapping)
+		async Task<List<Status>> Statuses(IReadOnlyCollection<PostEntity> posts, string viewerId, bool nested, CancellationToken token,
+			bool hideFromViewer = true)
 		{
 			var originalIds = posts.Where(p => p.ReblogOfPostId != default).Select(p => p.ReblogOfPostId).Distinct().ToList();
 			var originals = originalIds.Count == 0
@@ -164,7 +203,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			var mentionAccounts = mentionUris.Count == 0
 				? new Dictionary<string, ForeignAvatar>()
 				: (await _dbEntities.ForeignAvatars.Match(f => mentionUris.Contains(f.ActorURI)).ExecuteAsync(token)).ToDictionary(f => f.ActorURI);
-			var accounts = await Accounts(all.Select(AuthorOf), token);
+			var accounts = await Accounts(all.Select(AuthorOf).Concat(all.Select(p => p.WallOwnerAccountId).Where(w => w != default)), token);
 
 			var ids = all.Select(p => p.ID).ToList();
 			var favourited = viewerId == default
@@ -187,14 +226,20 @@ namespace PrivaPub.Api.Mastodon.Mappers
 					})
 					.OrderByDescending(e => e.Count)
 					.ToList());
+			var eventIds = all.Where(p => p.Event != default && p.IsFederatedCopy).Select(p => p.ID).ToList();
+			var participations = viewerId == default || eventIds.Count == 0
+				? new Dictionary<string, Models.Social.ParticipationState>()
+				: (await DB.Default.Find<Models.Social.Participation>().Match(p => p.AvatarId == viewerId && eventIds.Contains(p.PostId)).ExecuteAsync(token))
+					.ToDictionary(p => p.PostId, p => p.State);
 			var pollIds = all.Where(p => p.Poll != default).Select(p => p.ID).ToList();
 			var ownVotes = viewerId == default || pollIds.Count == 0
 				? new Dictionary<string, List<int>>()
 				: (await DB.Default.Find<PollVote>().Match(v => pollIds.Contains(v.PostId) && v.VoterAccountId == viewerId && v.IsLocalVoter).ExecuteAsync(token))
 					.GroupBy(v => v.PostId).ToDictionary(g => g.Key, g => g.Select(v => v.Choice).ToList());
-			var hidden = viewerId == default
+			var hidden = viewerId == default || !hideFromViewer
 				? new HashSet<string>()
 				: await Domain.Relationships.Hidden.AuthorsHiddenFrom(viewerId, all.Select(p => p.ActorURI), forNotifications: false, token);
+			var filters = await Domain.Social.Filters.Of(viewerId, token);
 			var reblogged = viewerId == default
 				? new HashSet<string>()
 				: (await _dbEntities.Posts.Match(p => p.AuthorAccountId == viewerId && ids.Contains(p.ReblogOfPostId) && !p.DeletedAt.HasValue).ExecuteAsync(token))
@@ -223,18 +268,21 @@ namespace PrivaPub.Api.Mastodon.Mappers
 					Bookmarked = bookmarked.Contains(post.ID),
 					Pinned = pinned.Contains(post.ID),
 					Sensitive = post.HasContentWarning,
-					SpoilerText = post.SpoilerText ?? (post.HasContentWarning ? post.Title ?? ActivityPubRenderer.ContentWarning : string.Empty),
+					//a remote post keeps its own summary: sensitive with none (Akkoma's sensitive media, Lemmy's NSFW) hides the
+					//media, never the words behind an invented warning; a local post warned without words gets the default one
+					SpoilerText = post.SpoilerText ?? (post.HasContentWarning && !post.IsFederatedCopy ? post.Title ?? ActivityPubRenderer.ContentWarning : string.Empty),
 					Visibility = Visibility(post.Visibility),
 					Language = post.Language,
 					MediaAttachments = post.Media.Count > 0 ? post.Media.Select(Media).ToList() : Playable(post),
 					Card = Card(post),
 					Poll = Poll(post, viewerId, ownVotes.GetValueOrDefault(post.ID)),
 					Emojis = Emojis(post.Emojis),
-					Privapub = Extension(post),
+					Privapub = Extension(post, accounts),
 					EmojiReactions = reactions.GetValueOrDefault(post.ID) ?? new(),
 					Pleroma = new PleromaStatus { EmojiReactions = reactions.GetValueOrDefault(post.ID) ?? new() },
-					Mentions = post.Mentions.Select(m => Mention(m, mentionAccounts)).Where(m => m != default).ToList(),
+					Mentions = post.Mentions.Where(m => !m.Silent).Select(m => Mention(m, mentionAccounts)).Where(m => m != default).ToList(),
-					Tags = post.Tags.Select(t => new StatusTag { Name = t, Url = ActivityPubRenderer.TagUrl(_localActors.BaseAddress, t) }).ToList()
+					Tags = post.Tags.Select(t => new StatusTag { Name = t, Url = ActivityPubRenderer.TagUrl(_localActors.BaseAddress, t) }).ToList(),
+					Filtered = filters.Of(post)
 				};
 				return status;
 			}
@@ -256,6 +304,9 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			{
 				status.QuotesCount = post.QuotesCount;
 				status.QuoteApproval = post.IsFederatedCopy ? Approval(post, viewerId) : LocalApproval(post, viewerId, followsAuthor.Contains(post.GroupUserId));
+				status.InteractionPolicy = Policies(post);
+				if (status.Privapub?.Event != default && participations.TryGetValue(post.ID, out var participation))
+					status.Privapub.Event.Participation = participation.ToString().ToLowerInvariant();
 				if (post.QuoteState == QuoteState.None)
 					return;
 				var state = post.QuoteState.ToString().ToLowerInvariant();
@@ -283,6 +334,8 @@ namespace PrivaPub.Api.Mastodon.Mappers
 						continue;
 					Quote(inner, original);
 					status.Reblog = inner;
+					status.Filtered = inner.Filtered;//a boost is filtered as what it boosts
+					status.Url = inner.Url;//a boost has no page of its own; /grunts would answer JSON to a browser
 					status.Content = string.Empty;
 					status.Reblogged = reblogged.Contains(original.ID);
 				}
@@ -326,6 +379,23 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			return new QuoteApprovalEntity { Automatic = everyone, CurrentUser = current };
 		}
 
+		// a remote post's canLike, canReply and canAnnounce, in GoToSocial's client terms; null when it states none
+		static InteractionPolicyEntity Policies(PostEntity post)
+		{
+			if (!post.IsFederatedCopy || post.LikePolicy == default && post.ReplyPolicy == default && post.AnnouncePolicy == default)
+				return default;
+			var collections = post.ActorURI?.TrimEnd('/');
+			string Named(string who) => Addressing.IsPublic(who) ? "public"
+				: who == post.ActorURI ? "author"
+				: who.EndsWith("/followers", StringComparison.Ordinal) && who.StartsWith(collections, StringComparison.Ordinal) ? "followers"
+				: who.EndsWith("/following", StringComparison.Ordinal) && who.StartsWith(collections, StringComparison.Ordinal) ? "following"
+				: who;
+			InteractionRuleEntity Rule(InteractionRule rule) => rule == default
+				? new InteractionRuleEntity { AutomaticApproval = new List<string> { "public" } }
+				: new InteractionRuleEntity { AutomaticApproval = rule.Automatic.Select(Named).Distinct().ToList(), ManualApproval = rule.Manual.Select(Named).Distinct().ToList() };
+			return new InteractionPolicyEntity { CanFavourite = Rule(post.LikePolicy), CanReply = Rule(post.ReplyPolicy), CanReblog = Rule(post.AnnouncePolicy) };
+		}
+
 		static QuoteApprovalEntity Approval(PostEntity post, string viewerId)
 		{
 			if (!post.IsFederatedCopy || post.Visibility is not (PostVisibility.Public or PostVisibility.Unlisted))
@@ -410,9 +480,12 @@ namespace PrivaPub.Api.Mastodon.Mappers
 		List<CustomEmojiEntity> Emojis(IEnumerable<CustomEmoji> emojis) =>
 			emojis?.Select(e => new CustomEmojiEntity { Shortcode = e.Shortcode, Url = Proxied(e.URL), StaticUrl = Proxied(e.URL) }).ToList() ?? new();
 
-		PrivaPubStatus Extension(PostEntity post) => new()
+		PrivaPubStatus Extension(PostEntity post, Dictionary<string, Account> accounts) => new()
 		{
+			Wall = post.WallOwnerAccountId == default || post.WallOwnerAccountId == AuthorOf(post) ? default : accounts.GetValueOrDefault(post.WallOwnerAccountId),
 			ObjectType = post.ObjectType,
+			Locked = post.LockedAt.HasValue,
+			Approval = post.Approval is ApprovalState.Pending or ApprovalState.Rejected ? post.Approval.ToString().ToLowerInvariant() : default,
 			Title = post.IsFederatedCopy ? post.Title : default,
 			Excerpt = post.Excerpt,
 			Cover = Proxied(post.CoverURL),
@@ -457,6 +530,10 @@ namespace PrivaPub.Api.Mastodon.Mappers
 				Status = post.Event.Status,
 				Category = post.Event.Category
 			},
+			Place = post.Place == default ? default : new PrivaPubPlace
+			{
+				Name = post.Place.Name, Latitude = post.Place.Latitude, Longitude = post.Place.Longitude, Country = post.Place.Country
+			},
 			Votes = new PrivaPubVotes { Up = post.FavouritesCount, Down = post.DownvotesCount }
 		};
 
@@ -511,6 +588,8 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			return default;
 		}
 
+		public PreviewCard LinkCard(string url, string title, string description, string image) => Card(url, title, description, image);
+
 		PreviewCard Card(string url, string title, string description, string image)
 		{
 			if (!Uri.TryCreate(url, UriKind.Absolute, out var uri))

PrivaPub/Controllers/ClientToServer/GroupController.cs

@@ -48,6 +48,18 @@ namespace PrivaPub.Controllers.ClientToServer
 		public async Task<IActionResult> Approve(GroupMembershipForm form, CancellationToken token) =>
 			!ModelState.IsValid ? Invalid() : Answer(await _groupUsersService.ApproveMember(User.GetUserId(), form, token));
 
+		[HttpGet, Route("/clientapi/group/members")]
+		public async Task<IActionResult> Members([FromQuery] string avatarId, [FromQuery] string groupId, CancellationToken token) =>
+			Answer(await _groupUsersService.GetMembers(User.GetUserId(), avatarId, groupId, token));
+
+		[HttpPost, Route("/clientapi/group/reject")]
+		public async Task<IActionResult> Reject(GroupMembershipForm form, CancellationToken token) =>
+			!ModelState.IsValid ? Invalid() : Answer(await _groupUsersService.RejectMember(User.GetUserId(), form, token));
+
+		[HttpPost, Route("/clientapi/group/remove")]
+		public async Task<IActionResult> Remove(GroupMembershipForm form, CancellationToken token) =>
+			!ModelState.IsValid ? Invalid() : Answer(await _groupUsersService.RemoveMember(User.GetUserId(), form, token));
+
 		IActionResult Invalid() => BadRequest(new WebResult().Invalidate(_localizer["Invalid model."]));
 
 		IActionResult Answer(WebResult result) => result.IsValid ? Ok(result.Data) : StatusCode(result.StatusCode, result);

PrivaPub/Controllers/ClientToServer/ModeratorController.cs

@@ -4,6 +4,7 @@ using Microsoft.AspNetCore.Mvc;
 using MongoDB.Entities;
 
 using PrivaPub.ClientModels;
+using PrivaPub.ClientModels.Admin;
 using PrivaPub.Extensions;
 using PrivaPub.Models.Social;
 
@@ -17,20 +18,20 @@ namespace PrivaPub.Controllers.ClientToServer
 		[HttpGet, Route("/clientapi/moderator/reports")]
 		public async Task<IActionResult> Reports([FromQuery] bool resolved, CancellationToken token) =>
 			Ok((await DB.Default.Find<Report>().Match(r => r.IsResolved == resolved).Sort(r => r.ID, Order.Descending).Limit(100).ExecuteAsync(token))
-				.Select(r => new
+				.Select(r => new ViewReport
 				{
-					r.ID,
+					ID = r.ID,
 					Reporter = r.ReporterAvatarId != default ? "local" : r.ReporterActorURI,
-					r.TargetAccountId,
+					TargetAccountId = r.TargetAccountId,
-					r.TargetActorURI,
+					TargetActorURI = r.TargetActorURI,
-					r.PostIds,
+					PostIds = r.PostIds,
-					r.ObjectURIs,
+					ObjectURIs = r.ObjectURIs,
-					r.Category,
+					Category = r.Category,
-					r.Comment,
+					Comment = r.Comment,
-					r.Forwarded,
+					Forwarded = r.Forwarded,
-					r.IsResolved,
+					IsResolved = r.IsResolved,
-					r.CreatedAt,
+					CreatedAt = r.CreatedAt,
-					r.ResolvedAt
+					ResolvedAt = r.ResolvedAt
 				}));
 
 		[HttpPost, Route("/clientapi/moderator/reports/{id}/resolve")]

PrivaPub/Controllers/ClientToServer/RootUserController.cs

@@ -227,7 +227,7 @@ namespace PrivaPub.Controllers.ClientToServer
 			if (string.Equals(avatarUserName, rootUserName?.Trim(), StringComparison.OrdinalIgnoreCase))
 				return Localizer["Your persona's username must differ from your login."];
 			if (await LocalActors.IsUserNameTaken(avatarUserName, token))
-				return Localizer["The username '{0}' is already take.", avatarUserName];
+				return Localizer["The username '{0}' is already taken.", avatarUserName];
 			return default;
 		}
 

PrivaPub/Domain/Content/ContentRenderer.cs

@@ -122,7 +122,7 @@ namespace PrivaPub.Domain.Content
 			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 }
+				return local is { IsFederated: true, IsCircle: false, IsServerActor: false }
 					? new ResolvedMention(local.Uri, local.UserName, local.Domain, local.Uri, true, local.Id, local.Inbox)
 					: default;
 			}

PrivaPub/Domain/Media/MediaProxy.cs

@@ -157,11 +157,11 @@ namespace PrivaPub.Domain.Media
 			}
 		}
 
-		//one pass: uploads left unattached for a day go, then the proxy cache is trimmed to its size, oldest first
+		//one pass: uploads left unattached for a day go (unless a scheduled post waits for them), then the proxy cache is trimmed to its size, oldest first
 		public async Task Sweep(CancellationToken token)
 		{
 			var cutoff = DateTime.UtcNow - UnattachedLifetime;
-			foreach (var stale in await DB.Default.Find<MediaAttachment>().Match(m => m.PostId == null && m.CreatedAt < cutoff).Limit(500).ExecuteAsync(token))
+			foreach (var stale in await DB.Default.Find<MediaAttachment>().Match(m => m.PostId == null && m.ScheduledStatusId == null && m.CreatedAt < cutoff).Limit(500).ExecuteAsync(token))
 				await _media.Delete(stale);
 			TrimProxyCache();
 		}

PrivaPub/Domain/Media/MediaService.cs

@@ -42,6 +42,9 @@ namespace PrivaPub.Domain.Media
 			["audio/mp4"] = "m4a", ["audio/x-m4a"] = "m4a", ["audio/flac"] = "flac", ["audio/webm"] = "webm"
 		};
 
+		// what an upload may be, as the instance API advertises it
+		public static IReadOnlyList<string> SupportedTypes => ImageTypes.Concat(AvTypes.Keys).ToList();
+
 		readonly IOptionsMonitor<MediaOptions> _options;
 		readonly ILocalActorService _localActors;
 		readonly IWebHostEnvironment _environment;