A located post reaches no home, its author's included

The fan-out put every post in its author's home, located ones too, while the Mastodon API looks past located posts
everywhere else. In the author's home a located post showed as public (the mapper has no word for it) and every action
on it answered 404: decePub's end-to-end runs, which write one from Milano for the globe, found it there. The fan-out
now gives a located post no home, no stream and no notification, and the home timeline passes over the entries left
from before. A located post is read through /clientapi/post/nearby and deleted through /clientapi/post/delete.
NearbyTests checks it has no TimelineEntry; the suite passes (881).

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

@@ -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;
@@ -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**;
@@ -195,9 +217,13 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
    when a refetch answers 404, which is why this matters.
    **Communities** are FEP-1b12 groups: `GroupDistributor` announces the whole activity (plus the object for new posts,
    for Mastodon), top-level posts are `Page`s with a `name`, posting follows `Group.PostingPolicy`.
-   Located posts (`LocalGeo`) are the only local-only posts.
+   Located posts (`LocalGeo`) are the only local-only posts. The Mastodon API looks past them everywhere, homes
+   included (the fan-out gives them no `TimelineEntry`, not even their author's): they are read through
+   `/clientapi/post/nearby` and deleted through `/clientapi/post/delete`.
 9. **A DM joins a conversation only by `DmGroup.ParticipantsKey`**, the exact set of its participants; a remote
    `context` decides nothing. DMs are `Post`s with `Visibility = Direct` and a `ConversationId` (`DmPost` is legacy).
+   `DmGroup.LastPostId` pages `/api/v1/conversations`, and `ConversationState` keeps each persona's read and removed
+   marks (`Domain/Statuses/ConversationStates.cs`; writing in a conversation reads it).
 10. **Nothing slow happens inside a request.** Deliveries and inbox processing are `Job`s (`Infrastructure/Jobs`):
     leased, retried on Mastodon's curve, at most two per host, paused per host by `RemoteInstance`. The inbox answers
     202 once it has verified and queued; a handler must be idempotent (unique `ObjectURI`, job `DedupeKey`).
@@ -216,6 +242,20 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
     fetched as context. Followers-only is detected by the author's stored `followers` URL.
 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
 
@@ -239,6 +279,11 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
 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, a remote post's own place (Pixelfed's `location`,
    never federated again), and up/down votes. Every media URL in it goes
@@ -289,7 +334,8 @@ 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.
@@ -362,7 +408,8 @@ 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
@@ -437,6 +484,10 @@ 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
@@ -459,9 +510,10 @@ 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.
@@ -469,7 +521,8 @@ 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
@@ -482,7 +535,7 @@ 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
@@ -490,7 +543,189 @@ 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.
@@ -498,6 +733,45 @@ 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

@@ -8,7 +8,14 @@ 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
 
@@ -19,7 +26,32 @@ and every run starting clean, with signed fetches required (as privapub.thepra.d
 - **Misskey 2026.10**
 - **Sharkey 2025.4.7**
 - **Akkoma 3.20.1**
-- **Lemmy 1.0.0-beta.2**
+- **Lemmy 1.0.0-beta.2**, and **Lemmy 0.19.20** (built with the platform's roots, so it trusts the pasture's CA)
+- **PeerTube 8.3.1**
+- **Pixelfed 0.14.4**
+- **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;
@@ -33,14 +65,22 @@ Checked both ways, where the peer has the feature:
 - communities and circles;
 - blocks and unfollows.
 
-`docs/INTEROP.md` has each peer's evidence and what is still expected to fail. PeerTube, PieFed, Mbin and the others are
+`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)
@@ -48,10 +88,20 @@ covered by unit tests written in their documents' shape.
 - [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 P7 and P8, and the per-platform notes in `docs/INTEROP.md`): FEP-9098 (custom
-emoji), FEP-7888 and FEP-f228 (threads), FEP-7628 (Move), FEP-8fcf (followers synchronisation), FEP-8967 (link
-attachments), FEP-521a and FEP-8b32 (keys and integrity proofs), FEP-ae0c (relays).
+emoji), FEP-7888 and FEP-f228 (threads), FEP-7628 (Move), FEP-8967 (link
+attachments), FEP-ae0c (relays).
 
 ## Actors
 
@@ -69,6 +119,8 @@ 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.
@@ -78,7 +130,12 @@ The names are the project's own and are stable; resolve actors through WebFinger
   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
 
@@ -86,7 +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.
@@ -95,9 +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
 
@@ -106,28 +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.
@@ -137,6 +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.
@@ -159,6 +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
@@ -182,6 +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).
@@ -210,10 +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
@@ -226,10 +410,16 @@ Posts with a location (shown to nearby users of this server) never leave the ser
   carry is deleted (then 410); a persona's boost id sends a browser to the boosted post. `Follow`, `Like`, `Block` and
   the `Accept`, `Reject` and `Undo` that answer them do not, because serving them would reveal who follows, likes and
   blocks whom. Neither do `Update`, `Delete`, `EmojiReact`, `QuoteRequest` and its answers, `Flag`, `Ignore` or poll
-  votes. All of them are always sent with their object embedded.
+  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.** 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.
+- **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
 
@@ -239,4 +429,15 @@ Posts with a location (shown to nearby users of this server) never leave the ser
 - Collections expose counts, not members: `/groupies` and `/stalking` give the same totals as the Mastodon API's
   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.
-- Only `rsa-sha256`-style keys are verified. RFC 9421 signatures are planned.
+- 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/Domain/NearbyTests.cs

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

PrivaPub.Tests/Federation/BackfillTests.cs

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

PrivaPub.Tests/Federation/ChatMessageSoftwareTests.cs

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

PrivaPub.Tests/Federation/CommunityEditsTests.cs

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

PrivaPub.Tests/Federation/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")
-			Assert.Equal(("dropped", "unsupported", "Like"), (liked.Outcome, liked.Reason, liked.Object));
-			Assert.Equal(("dropped", "unsupported", "Undo"), (unliked.Outcome, unliked.Reason, unliked.Object));
+			//Lemmy relays its members' votes inside the community's Announce (G-0003): a voter on the community's own server
+			//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("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/ParticipationTests.cs

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

PrivaPub.Tests/Federation/ReactionTests.cs

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

PrivaPub.Tests/Federation/RelayTests.cs

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

PrivaPub.Tests/Federation/RemoteHandleTests.cs

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

PrivaPub.Tests/Federation/ReplyRelayTests.cs

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

PrivaPub.Tests/Federation/ReusedIdTests.cs

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

PrivaPub.Tests/Federation/ServiceReportTests.cs

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

PrivaPub.Tests/Federation/SharedInboxTests.cs

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

PrivaPub.Tests/Federation/WallTests.cs

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

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

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

PrivaPub.Tests/Fixtures/pleroma/edited.json

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

PrivaPub.Tests/Http/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 = $"{Base}/peasants/privapub_reports";
+			Assert.Equal(id, actor["id"]!.GetValue<string>());
+			Assert.Equal("Service", actor["type"]!.GetValue<string>());
+			Assert.Equal("privapub_reports", actor["preferredUsername"]!.GetValue<string>());
+			Assert.Equal(id + "/mouth", actor["inbox"]!.GetValue<string>());
+			Assert.Equal(id + "/anus", actor["outbox"]!.GetValue<string>());
+			Assert.Equal(id, actor["url"]!.GetValue<string>());
+			Assert.Equal(id + "#main-key", actor["publicKey"]!["id"]!.GetValue<string>());
+			Assert.Equal(id, actor["publicKey"]!["owner"]!.GetValue<string>());
+			Assert.NotEqual(instance.Json["publicKey"]!["publicKeyPem"]!.GetValue<string>(), actor["publicKey"]!["publicKeyPem"]!.GetValue<string>());
+			Assert.False(actor["discoverable"]!.GetValue<bool>());
+			Assert.Null(actor["wall"]);
+			Assert.Null(actor["implements"]);
+			Assert.Equal(HttpStatusCode.OK, browser.Status);
+			Assert.Equal("Service", browser.Json["type"]!.GetValue<string>());
+			Assert.Equal(HttpStatusCode.OK, outbox.Status);
+			Assert.Equal(0, outbox.Json["totalItems"]!.GetValue<int>());
+		}
+
 		[Fact]
 		public async Task Users_moves_permanently_to_peasants_and_unknown_actors_are_404()
 		{
@@ -170,7 +215,7 @@ namespace PrivaPub.Tests.Http
 			var announce = items[0];
 			Assert.Equal("Announce", announce["type"]!.GetValue<string>());
 			Assert.Equal(reblog.ObjectURI, announce["id"]!.GetValue<string>());
-			Assert.Equal($"{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>());
 
@@ -436,7 +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);
@@ -451,7 +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]
@@ -492,7 +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();
@@ -518,6 +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/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 +41,8 @@ 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.Null(v2.Body["configuration"]!["urls"]!["streaming"]);//nothing streams yet, so nothing is advertised
+			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"));
@@ -69,25 +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

@@ -167,6 +167,8 @@ namespace PrivaPub.Tests.Http
 			var key = group.Text("group_key");
 
 			Assert.Equal($"grouped-favourite-{id}", key);
+			// told alone (v1, a stream), each notification names the group it belongs to
+			Assert.All((await author.Client.Get("/api/v1/notifications?types[]=favourite")).Ok().Array, n => Assert.Equal(key, n.Text("group_key")));
 			Assert.Equal(2, group.Number("notifications_count"));
 			Assert.Equal(2, group["sample_account_ids"]!.AsArray().Count);
 			Assert.Equal(id, group.Text("status_id"));
@@ -174,6 +176,11 @@ namespace PrivaPub.Tests.Http
 			Assert.True((await author.Client.Get("/api/v2/notifications/unread_count")).Ok().Body.Number("count") >= 1);
 			Assert.Equal(key, Assert.Single((await author.Client.Get($"/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);
 		}

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"));

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/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

@@ -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]
@@ -200,6 +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 RejectHandler(Db, Local, Quotes),
+				new AcceptHandler(Db, Local, Quotes, Approvals, Participations, Relays, Queue),
+				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 CreateHandler(Db, Local, Remote, Delivery, new NoBlocks(), Fanout, RemotePosts, Groups, Records, Polls, new NoPreviews(), 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, Approvals, Relays, Walls),
 				new DeleteHandler(Db, Local, Remote, Delivery, Groups, Quotes),
-				new UpdateHandler(Db, Local, Remote, Groups, Records, Quotes),
-				new FlagHandler(Db, Local)
+				new UpdateHandler(Db, Local, Remote, Groups, Records, Quotes, Delivery),
+				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);
-			Follows = new FollowService(Db, Local, Remote, Delivery, new KeyLocalizer<GenericRes>(), NullLogger<FollowService>.Instance);
+			((AnnounceHandler)Handlers.First(h => h is AnnounceHandler)).Relays = Handlers;
+			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);
-			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == dedupe).ExecuteFirstAsync();
-			if (job != default)
+			// the job this delivery queued: under its id, or apart (a forwarded copy; an id its sender reused)
+			var id = activity is JsonObject ? activity["id"]?.GetValue<string>() : 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

@@ -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}");

PrivaPub.Tests/Support/RemoteActor.cs

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

PrivaPub/Api/Mastodon/Controllers/AccountsController.cs

@@ -115,7 +115,7 @@ 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();
@@ -134,7 +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)
@@ -152,7 +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));
@@ -342,9 +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());
 
@@ -385,8 +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 domainBlocked = remote != default && await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == MyId && b.Domain == remote.Domain).ExecuteAnyAsync(token);
+			var blockedBy = local != default
+				? 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/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

@@ -40,6 +40,10 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		string Domain => new Uri(_localActors.BaseAddress).Authority;
 
+		// 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);
+
 		// 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 };
 
@@ -82,7 +86,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				description = Description,
 				email = string.Empty,
 				version = Version,
-				urls = new { },//no streaming API yet, so none is advertised
+				urls = new { streaming_api = Streaming },
 				stats = new { user_count = users, status_count = statuses, domain_count = domains },
 				thumbnail = $"{_localActors.BaseAddress}/media/missing-header.png",
 				languages = LanguageCodes(HttpContext.RequestServices),
@@ -115,7 +119,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			languages = LanguageCodes(HttpContext.RequestServices),
 			configuration = new
 			{
-				urls = new { },//no streaming API yet, so none is advertised
+				urls = new { streaming = Streaming },
 				accounts = new { max_featured_tags = 0, max_pinned_statuses = StatusesController.MaxPins },
 				statuses = Statuses,
 				media_attachments = MediaAttachments,

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),
-			preview_url = _media.Url(attachment.PreviewPath ?? attachment.FilePath),
+			url = media.Url(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/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;
@@ -55,7 +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);
@@ -72,59 +73,76 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			{
 				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)
-				results.Hashtags.Add(new { name = tag.ToLowerInvariant(), url = $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(tag.ToLowerInvariant())}", history = Array.Empty<object>() });
+			// an account's handle asks for the account, never for posts that happen to share its words
+			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>
 		{
@@ -140,23 +158,12 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		// 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/directory"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult Directory() => Json(Array.Empty<object>());
-
 		[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/tags/{name}"), Microsoft.AspNetCore.Authorization.AllowAnonymous]
-		public IActionResult Tag(string name)
-		{
-			var tag = name?.TrimStart('#').ToLowerInvariant() ?? string.Empty;
-			var baseAddress = HttpContext.RequestServices.GetRequiredService<Federation.Actors.ILocalActorService>().BaseAddress;
-			return Json(new { name = tag, url = $"{baseAddress}/tags/{Uri.EscapeDataString(tag)}", history = Array.Empty<object>(), following = false });
-		}
-
 		[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 }));
@@ -175,29 +182,5 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				+ "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>"
 		});
-
-		[HttpGet("/api/v1/notifications/policy"), Scope("read:notifications")]
-		public IActionResult NotificationPolicyV1() => Json(new
-		{
-			filter_not_following = false,
-			filter_not_followers = false,
-			filter_new_accounts = false,
-			filter_private_mentions = false,
-			summary = new { pending_requests_count = 0, pending_notifications_count = 0 }
-		});
-
-		[HttpGet("/api/v2/notifications/policy"), Scope("read:notifications")]
-		public IActionResult NotificationPolicyV2() => Json(new
-		{
-			for_not_following = "accept",
-			for_not_followers = "accept",
-			for_new_accounts = "accept",
-			for_private_mentions = "accept",
-			for_limited_accounts = "accept",
-			summary = new { pending_requests_count = 0, pending_notifications_count = 0 }
-		});
-
-		[HttpGet("/api/v1/notifications/requests"), Scope("read:notifications")]
-		public IActionResult NotificationRequests() => Json(Array.Empty<object>());
 	}
 }

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),
-				InReplyTo = Params.Get("in_reply_to_id"),
+				Visibility = Params.Get("visibility") ?? Me.Settings.DefaultVisibility,
+				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,
-						Params.Bool("poll[hide_totals]") == true)
+					? new ScheduledPoll
+					{
+						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
-		{
-			"unlisted" => PostVisibility.Unlisted,
-			"private" => PostVisibility.FollowersOnly,
-			"direct" => PostVisibility.Direct,
-			_ => PostVisibility.Public
-		};
+		static PostVisibility Visibility(string value) => ScheduledStatuses.Visibility(value);
 	}
 }

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;
@@ -30,9 +33,19 @@ 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);
+			// (located posts once reached their author's home: the entries left from then are passed over)
+			var posts = (await _dbEntities.Posts.Match(p => ids.Contains(p.ID) && p.Visibility != PostVisibility.LocalGeo).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);
 			Link("/api/v1/timelines/home", entries.LastOrDefault()?.PostId, entries.FirstOrDefault()?.PostId);
 			return Json(statuses);
@@ -61,9 +74,6 @@ 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 +88,79 @@ 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))
-				.Sort(g => g.UpdatedAt, Order.Descending).Limit(Limit()).ExecuteAsync(token);
-			var conversations = new List<Conversation>();
-			foreach (var group in groups)
-			{
-				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);
+			var groups = await Page.From(Params, Limit(20, 40)).Fetch(
+				_dbEntities.DmGroups.Match(g => !g.DeletionAt.HasValue && g.LastPostId != null && g.Members.Any(m => !m.IsForeign && m.AvatarId == MyId)),
+				g => g.LastPostId, token);
+			Link("/api/v1/conversations", groups.LastOrDefault()?.LastPostId, groups.FirstOrDefault()?.LastPostId);
+			return Json(await ConversationsOf(groups, token));
 		}
 
+		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);
-			return Json(new Conversation { Id = group.ID, LastStatus = last == default ? default : await _mapper.Status(last, MyId, token) });
+			await ConversationStates.Read(MyId, group.ID, group.LastPostId, 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 +189,10 @@ 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 +207,7 @@ 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",
@@ -182,6 +234,9 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			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)
@@ -191,6 +246,9 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			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)
 		{
@@ -201,11 +259,11 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		// 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.
-		static readonly HashSet<string> DefaultGrouped = new() { "favourite", "reblog", "follow" };
+		internal static readonly HashSet<string> DefaultGrouped = new() { "favourite", "reblog", "follow" };
 
 		HashSet<string> Grouped() => Params.List("grouped_types") is { Count: > 0 } chosen ? chosen.ToHashSet() : DefaultGrouped;
 
-		static string GroupKey(NotificationEntity n, ISet<string> grouped) =>
+		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}"
@@ -234,7 +292,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 
 		async Task<List<NotificationEntity>> Members(string key, CancellationToken token) =>
 			InGroup(key) is { } filter
-				? await _dbEntities.Notifications.Match(filter).Sort(n => n.ID, Order.Descending).Limit(80).ExecuteAsync(token)
+				? 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)
@@ -245,7 +303,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			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(InGroup(group.Key), token);
+				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,
@@ -341,34 +400,13 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		[HttpGet("/api/v1/notifications/unread_count"), Scope("read:notifications")]
 		public async Task<IActionResult> UnreadCount(CancellationToken token)
 		{
-			var unread = await DB.Default.Find<NotificationEntity>().Match(n => n.AvatarId == MyId && !n.IsRead)
+			var unread = await DB.Default.Find<NotificationEntity>().Match(n => n.AvatarId == MyId && !n.IsRead).Match(NotFiltered)
 				.Sort(n => n.ID, Order.Descending).Limit(Math.Clamp(Params.Int("limit") ?? 100, 1, 1000)).ExecuteAsync(token);
 			return Json(new { count = (await Map(unread, token)).Count });
 		}
 
-		async Task<List<Entities.Notification>> Map(List<NotificationEntity> notifications, CancellationToken token)
-		{
-			var accounts = await _mapper.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 _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

@@ -32,6 +32,7 @@
 		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 @@
 	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; }
@@ -74,6 +77,7 @@
 		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();
 	}
 
@@ -146,6 +150,7 @@
 		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
@@ -178,6 +183,48 @@
 		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; }
@@ -266,13 +313,28 @@
 		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

@@ -21,6 +21,30 @@ namespace PrivaPub.Api.Mastodon.Mappers
 
 		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)
 		{

PrivaPub/Api/Mastodon/Mappers/MastodonMapper.cs

@@ -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";
 
@@ -140,18 +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) && !f.DeletionAt.HasValue).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
@@ -163,7 +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
@@ -186,14 +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))
@@ -222,18 +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(),
-					Tags = post.Tags.Select(t => new StatusTag { Name = t, Url = ActivityPubRenderer.TagUrl(_localActors.BaseAddress, t) }).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(),
+					Filtered = filters.Of(post)
 				};
 				return status;
 			}
@@ -255,6 +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();
@@ -282,6 +334,7 @@ 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),
@@ -515,6 +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,
-					r.TargetActorURI,
-					r.PostIds,
-					r.ObjectURIs,
-					r.Category,
-					r.Comment,
-					r.Forwarded,
-					r.IsResolved,
-					r.CreatedAt,
-					r.ResolvedAt
+					TargetAccountId = r.TargetAccountId,
+					TargetActorURI = r.TargetActorURI,
+					PostIds = r.PostIds,
+					ObjectURIs = r.ObjectURIs,
+					Category = r.Category,
+					Comment = r.Comment,
+					Forwarded = r.Forwarded,
+					IsResolved = r.IsResolved,
+					CreatedAt = r.CreatedAt,
+					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/Privacy/VisibilityPolicy.cs

@@ -1,8 +1,10 @@
 using MongoDB.Entities;
 
+using PrivaPub.Models.Federation;
 using PrivaPub.Models.Group;
 using PrivaPub.Models.Post;
 using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
 
 using System.Linq.Expressions;
 
@@ -47,6 +49,31 @@ namespace PrivaPub.Domain.Privacy
 			};
 		}
 
+		// A remote account may see a post, and so like, react to, vote on or downvote it, when the post was for it: anyone for
+		// public and unlisted, an addressed account for a DM, a follower or an addressed account for followers-only (our own
+		// followers-only posts are addressed to the followers collection, never to each follower), a member for a circle.
+		// Accounts only: the instance-actor alias of SignedFetchAuthorizer.MayRead is for refetches, never for interactions.
+		public static async Task<bool> RemoteCanSee(Post post, ForeignAvatar actor, CancellationToken token)
+		{
+			if (!Shown(post) || actor == default || string.IsNullOrEmpty(actor.ActorURI))
+				return false;
+			if (IsPublicCompiled(post))
+				return true;
+			var addressed = post.To.Contains(actor.ActorURI) || post.Cc.Contains(actor.ActorURI) || post.Mentions.Any(m => m.ActorURI == actor.ActorURI);
+			return post.Visibility switch
+			{
+				PostVisibility.Direct => addressed,
+				//a remote author's followers live on other servers too; we know only who it addressed
+				PostVisibility.FollowersOnly => addressed || !post.IsFederatedCopy && !string.IsNullOrEmpty(post.GroupUserId) && await DB.Default.Find<Follower>()
+					.Match(f => f.LocalActorId == post.GroupUserId && f.LocalActorKind == LocalActorKind.Person && f.IsAccepted && f.ActorURI == actor.ActorURI)
+					.ExecuteAnyAsync(token),
+				PostVisibility.Circle => !string.IsNullOrEmpty(post.GroupId) && await DB.Default.Find<GroupEntity>()
+					.Match(g => g.ID == post.GroupId && g.Members.Any(m => m.IsForeign && m.AvatarId == actor.ActorURI))
+					.ExecuteAnyAsync(token),
+				_ => false
+			};
+		}
+
 		static async Task<bool> FollowsAuthor(string viewerAvatarId, Post post, CancellationToken token)
 		{
 			if (!string.IsNullOrEmpty(post.ActorURI))

PrivaPub/Domain/Relationships/RelationshipService.cs

@@ -7,6 +7,7 @@ using PrivaPub.Federation.Outbox;
 using PrivaPub.Federation.Rendering;
 using PrivaPub.Models.Federation;
 using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
 using PrivaPub.StaticServices;
 
 using System.Text.Json.Nodes;
@@ -141,11 +142,14 @@ namespace PrivaPub.Domain.Relationships
 			catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
 			{
 			}
-			foreach (var following in await _dbEntities.Followings.Match(f => f.AvatarId == me.Id && !f.TargetIsLocal).ExecuteAsync(token))
-				if (Hidden.HostMatches(following.TargetActorURI, domain))
+			var followings = await _dbEntities.Followings.Match(f => f.AvatarId == me.Id && !f.TargetIsLocal).ExecuteAsync(token);
+			var followers = await _dbEntities.Followers.Match(f => f.LocalActorId == me.Id).ExecuteAsync(token);
+			var handles = await Hidden.HandleDomains(followings.Select(f => f.TargetActorURI).Concat(followers.Select(f => f.ActorURI)).ToList(), token);
+			foreach (var following in followings)
+				if (Hidden.Blocks(domain, following.TargetActorURI, handles.GetValueOrDefault(following.TargetActorURI)))
 					await _follows.UnfollowAs(me, following.TargetActorURI, token);
-			foreach (var follower in await _dbEntities.Followers.Match(f => f.LocalActorId == me.Id).ExecuteAsync(token))
-				if (Hidden.HostMatches(follower.ActorURI, domain))
+			foreach (var follower in followers)
+				if (Hidden.Blocks(domain, follower.ActorURI, handles.GetValueOrDefault(follower.ActorURI)))
 					await DB.Default.DeleteAsync<Follower>(follower.ID);
 		}
 
@@ -167,8 +171,23 @@ namespace PrivaPub.Domain.Relationships
 	public static class Hidden
 	{
 		public static bool HostMatches(string actorUri, string domain) =>
-			Uri.TryCreate(actorUri, UriKind.Absolute, out var uri)
-			&& (uri.Host.Equals(domain, StringComparison.OrdinalIgnoreCase) || uri.Host.EndsWith("." + domain, StringComparison.OrdinalIgnoreCase));
+			Uri.TryCreate(actorUri, UriKind.Absolute, out var uri) && IsOn(uri.Host, domain);
+
+		static bool IsOn(string host, string domain) =>
+			host.Equals(domain, StringComparison.OrdinalIgnoreCase) || host.EndsWith("." + domain, StringComparison.OrdinalIgnoreCase);
+
+		// a server blocked by a persona hides an account whose actor is on it, or whose handle is (its domain apart from its
+		// actor's host, FEP-2c59: the servers Mastodon lists as blocked are its handles' domains)
+		public static bool Blocks(string domain, string actorUri, string handleDomain) =>
+			HostMatches(actorUri, domain) || (!string.IsNullOrEmpty(handleDomain) && IsOn(handleDomain.Split(':')[0], domain));
+
+		// the domains of these accounts' handles, for those known
+		public static async Task<Dictionary<string, string>> HandleDomains(List<string> actorUris, CancellationToken token) =>
+			actorUris.Count == 0
+				? []
+				: (await DB.Default.Find<ForeignAvatar>().Match(a => actorUris.Contains(a.ActorURI))
+					.Project(a => new ForeignAvatar { ActorURI = a.ActorURI, Domain = a.Domain }).ExecuteAsync(token))
+					.GroupBy(a => a.ActorURI).ToDictionary(g => g.Key, g => g.First().Domain);
 
 		public static async Task<HashSet<string>> AuthorsHiddenFrom(string avatarId, IEnumerable<string> actorUris, bool forNotifications, CancellationToken token)
 		{
@@ -179,12 +198,18 @@ namespace PrivaPub.Domain.Relationships
 			var now = DateTime.UtcNow;
 			foreach (var block in await DB.Default.Find<Block>().Match(b => b.AvatarId == avatarId && uris.Contains(b.TargetActorURI)).ExecuteAsync(token))
 				hidden.Add(block.TargetActorURI);
+			//an account that blocked the persona is hidden from it too, as Mastodon hides it from the blocked account's home
+			foreach (var blocker in await DB.Default.Find<BlockedBy>().Match(b => b.AvatarId == avatarId && uris.Contains(b.ActorURI)).ExecuteAsync(token))
+				hidden.Add(blocker.ActorURI);
 			foreach (var mute in await DB.Default.Find<Mute>().Match(m => m.AvatarId == avatarId && uris.Contains(m.TargetActorURI)).ExecuteAsync(token))
 				if ((mute.ExpiresAt == null || mute.ExpiresAt > now) && (!forNotifications || mute.HideNotifications))
 					hidden.Add(mute.TargetActorURI);
 			var domains = await DB.Default.Find<AccountDomainBlock>().Match(b => b.AvatarId == avatarId).ExecuteAsync(token);
+			if (domains.Count == 0)
+				return hidden;
+			var handles = await HandleDomains(uris, token);
 			foreach (var uri in uris)
-				if (domains.Any(d => HostMatches(uri, d.Domain)))
+				if (domains.Any(d => Blocks(d.Domain, uri, handles.GetValueOrDefault(uri))))
 					hidden.Add(uri);
 			return hidden;
 		}
@@ -198,11 +223,17 @@ namespace PrivaPub.Domain.Relationships
 			var now = DateTime.UtcNow;
 			foreach (var block in await DB.Default.Find<Block>().Match(b => ids.Contains(b.AvatarId) && b.TargetActorURI == actorUri).ExecuteAsync(token))
 				hiding.Add(block.AvatarId);
+			foreach (var blocked in await DB.Default.Find<BlockedBy>().Match(b => ids.Contains(b.AvatarId) && b.ActorURI == actorUri).ExecuteAsync(token))
+				hiding.Add(blocked.AvatarId);
 			foreach (var mute in await DB.Default.Find<Mute>().Match(m => ids.Contains(m.AvatarId) && m.TargetActorURI == actorUri).ExecuteAsync(token))
 				if (mute.ExpiresAt == null || mute.ExpiresAt > now)
 					hiding.Add(mute.AvatarId);
-			foreach (var block in await DB.Default.Find<AccountDomainBlock>().Match(b => ids.Contains(b.AvatarId)).ExecuteAsync(token))
-				if (HostMatches(actorUri, block.Domain))
+			var domains = await DB.Default.Find<AccountDomainBlock>().Match(b => ids.Contains(b.AvatarId)).ExecuteAsync(token);
+			if (domains.Count == 0)
+				return hiding;
+			var handle = (await HandleDomains([actorUri], token)).GetValueOrDefault(actorUri);
+			foreach (var block in domains)
+				if (Blocks(block.Domain, actorUri, handle))
 					hiding.Add(block.AvatarId);
 			return hiding;
 		}

PrivaPub/Domain/Relationships/ReportService.cs

@@ -1,6 +1,7 @@
 using MongoDB.Entities;
 
 using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Inbox;
 using PrivaPub.Federation.Outbox;
 using PrivaPub.Federation.Rendering;
 using PrivaPub.Models.Social;
@@ -50,12 +51,41 @@ namespace PrivaPub.Domain.Relationships
 				PostIds = posts.Select(p => p.ID).ToList(),
 				ObjectURIs = posts.Select(p => p.ObjectURI).ToList(),
 				Comment = comment?.Trim(),
-				Category = category is "spam" or "legal" or "violation" ? category : "other",
-				Forwarded = forward && remoteTarget != default
+				Category = category is "spam" or "legal" or "violation" ? category : "other"
 			};
 			await DB.Default.SaveAsync(report, token);
+			if (!forward || remoteTarget == default)
+				return report;
 
-			if (report.Forwarded)
+			// to the community of each post made in one on a server that takes reports only in Lemmy's shape
+			var flagged = 0;
+			var reason = string.IsNullOrEmpty(report.Comment) ? report.Category : report.Comment;
+			foreach (var post in posts)
+			{
+				var community = await Communities.Of(post, _dbEntities, token);
+				if (community == default || !await TakesServiceReports(community, token))
+					continue;
+				var group = await _dbEntities.ForeignAvatars.Match(a => a.ActorURI == community).ExecuteFirstAsync(token);
+				var inbox = string.IsNullOrEmpty(group?.SharedInboxURL) ? group?.InboxURL : group.SharedInboxURL;
+				if (string.IsNullOrEmpty(inbox))
+					continue;
+				var serviceReporter = await _localActors.GetReporterActor(token);
+				await _delivery.Enqueue(serviceReporter, new[] { inbox }, new JsonObject
+				{
+					["@context"] = ActivityPubRenderer.ActivityStreams,
+					["id"] = serviceReporter.ActivityUri($"flag-{report.ID}-{++flagged}"),
+					["type"] = "Flag",
+					["actor"] = serviceReporter.Uri,
+					["to"] = new JsonArray(community),
+					["audience"] = community,
+					["object"] = post.ObjectURI,
+					["summary"] = reason,
+					["content"] = reason
+				}, token);
+			}
+			// every other server, the author's, as before: an account alone, or posts outside such communities, go nowhere when
+			// the author's server takes reports only in Lemmy's shape
+			if (!await TakesServiceReports(targetUri, token))
 			{
 				var instance = await _localActors.GetInstanceActor(token);
 				var flag = new JsonObject
@@ -68,8 +98,30 @@ namespace PrivaPub.Domain.Relationships
 					["object"] = new JsonArray(report.ObjectURIs.Prepend(targetUri).Select(u => (JsonNode)u).ToArray())
 				};
 				await _delivery.Enqueue(instance, new[] { remoteTarget.SharedInboxURL ?? remoteTarget.InboxURL }, flag, token);
+				flagged++;
+			}
+			if (flagged > 0)
+			{
+				report.Forwarded = true;
+				await DB.Default.Update<Report>().MatchID(report.ID).Modify(r => r.Forwarded, true).ExecuteAsync(token);
 			}
 			return report;
 		}
+
+		// The second place PrivaPub decides by a server's software (owner decision 2026-10-06): Lemmy takes a report only from a
+		// person or a service, about one post or comment, addressed to its community, so a report for it leaves in that shape
+		// from the server's anonymous reporter; a server joins only once the pasture shows it stores such a report with its
+		// reason. PieFed (which drops a report from an Application) and Mbin (which reads the reason from summary alone) did on
+		// 2026-10-06. NodeInfo names them: they speak Lemmy's shapes, and nothing else tells them apart.
+		static readonly HashSet<string> ServiceReportTakers = new(StringComparer.Ordinal) { "lemmy", "piefed", "mbin" };
+
+		static async Task<bool> TakesServiceReports(string actorUri, CancellationToken token)
+		{
+			if (!Uri.TryCreate(actorUri, UriKind.Absolute, out var uri))
+				return false;
+			var host = uri.Host;
+			var instance = await DB.Default.Find<Models.Jobs.RemoteInstance>().Match(i => i.Host == host).ExecuteFirstAsync(token);
+			return instance?.Software is { } software && ServiceReportTakers.Contains(software.ToLowerInvariant());
+		}
 	}
 }

PrivaPub/Domain/Social/Filters.cs

@@ -0,0 +1,115 @@
+using System.Text.RegularExpressions;
+
+using MongoDB.Entities;
+
+using PrivaPub.Api.Mastodon.Entities;
+using PrivaPub.Models.Social;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Domain.Social
+{
+	// A viewer's active filters, matched against posts as Mastodon matches them: a keyword anywhere in the post's words
+	// (its warning, title, text, poll options and media descriptions), case-insensitive, whole words when asked (a word
+	// boundary only where the keyword starts or ends with a word character); a filtered status by its id.
+	public sealed class Filters
+	{
+		static readonly AngleSharp.Html.Parser.HtmlParser Html = new();
+
+		readonly List<(PersonaFilter Filter, FilterEntity View, List<(string Keyword, Regex Pattern)> Keywords, HashSet<string> PostIds)> _active;
+
+		Filters(List<PersonaFilter> filters)
+		{
+			var now = DateTime.UtcNow;
+			_active = filters.Where(f => f.IsActive(now))
+				.Select(f => (f, View(f), f.Keywords.Select(k => (k.Keyword, Pattern(k))).ToList(), f.Statuses.Select(s => s.PostId).ToHashSet()))
+				.ToList();
+		}
+
+		public static readonly Filters None = new(new List<PersonaFilter>());
+
+		public static async Task<Filters> Of(string viewerId, CancellationToken token) =>
+			viewerId == default ? None : new Filters(await DB.Default.Find<PersonaFilter>().Match(f => f.AvatarId == viewerId).ExecuteAsync(token));
+
+		public bool IsEmpty => _active.Count == 0;
+
+		public static Regex Pattern(FilterKeyword keyword)
+		{
+			var escaped = Regex.Escape(keyword.Keyword ?? string.Empty);
+			if (keyword.WholeWord)
+			{
+				var start = Regex.IsMatch(keyword.Keyword ?? string.Empty, @"^\w") ? @"\b" : string.Empty;
+				var end = Regex.IsMatch(keyword.Keyword ?? string.Empty, @"\w$") ? @"\b" : string.Empty;
+				escaped = start + escaped + end;
+			}
+			return new Regex(escaped, RegexOptions.IgnoreCase | RegexOptions.CultureInvariant, TimeSpan.FromMilliseconds(50));
+		}
+
+		public List<FilterResultEntity> Of(PostEntity post)
+		{
+			if (_active.Count == 0 || post == default)
+				return new List<FilterResultEntity>();
+			string words = default;
+			var results = new List<FilterResultEntity>();
+			foreach (var (filter, view, keywords, postIds) in _active)
+			{
+				var keywordMatches = new List<string>();
+				if (keywords.Count > 0)
+				{
+					words ??= Words(post);
+					foreach (var (keyword, pattern) in keywords)
+						if (Matches(pattern, words))
+							keywordMatches.Add(keyword);
+				}
+				var statusMatches = postIds.Contains(post.ID) ? new List<string> { filter.Statuses.First(s => s.PostId == post.ID).Id } : new List<string>();
+				if (keywordMatches.Count > 0 || statusMatches.Count > 0)
+					results.Add(new FilterResultEntity
+					{
+						Filter = view,
+						KeywordMatches = keywordMatches.Count > 0 ? keywordMatches : default,
+						StatusMatches = statusMatches.Count > 0 ? statusMatches : default
+					});
+			}
+			return results;
+		}
+
+		static bool Matches(Regex pattern, string words)
+		{
+			try
+			{
+				return pattern.IsMatch(words);
+			}
+			catch (RegexMatchTimeoutException)
+			{
+				return false;
+			}
+		}
+
+		static string Words(PostEntity post)
+		{
+			var text = !string.IsNullOrEmpty(post.Text) && post.IsFederatedCopy == false
+				? post.Text
+				: string.IsNullOrEmpty(post.ContentHtml) ? post.Text : Html.ParseDocument($"<body>{post.ContentHtml}</body>").Body!.TextContent;
+			return string.Join("\n", new[] { post.SpoilerText, post.Title, text }
+				.Concat(post.Poll?.Options.Select(o => o.Title) ?? Enumerable.Empty<string>())
+				.Concat(post.Media.Select(m => m.Description))
+				.Where(s => !string.IsNullOrEmpty(s)));
+		}
+
+		public static FilterEntity View(PersonaFilter filter) => new()
+		{
+			Id = filter.ID,
+			Title = filter.Title,
+			Context = filter.Context,
+			ExpiresAt = filter.ExpiresAt.HasValue ? Api.Mastodon.Infrastructure.MastodonJson.Time(filter.ExpiresAt.Value) : default,
+			FilterAction = filter.Action,
+			Keywords = filter.Keywords.Select(Keyword).ToList(),
+			Statuses = filter.Statuses.Select(Status).ToList()
+		};
+
+		public static FilterKeywordEntity Keyword(FilterKeyword keyword) =>
+			new() { Id = keyword.Id, Keyword = keyword.Keyword, WholeWord = keyword.WholeWord };
+
+		public static FilterStatusEntity Status(FilterStatus status) => new() { Id = status.Id, StatusId = status.PostId };
+	}
+}

PrivaPub/Domain/Social/FollowResender.cs

@@ -0,0 +1,27 @@
+namespace PrivaPub.Domain.Social
+{
+	// sends again, now and then, the follow requests still unanswered (FollowService.ResendPending)
+	public sealed class FollowResender(IServiceScopeFactory scopes, ILogger<FollowResender> logger) : BackgroundService
+	{
+		static readonly TimeSpan Every = TimeSpan.FromMinutes(15);
+
+		protected override async Task ExecuteAsync(CancellationToken token)
+		{
+			using var timer = new PeriodicTimer(Every);
+			while (await timer.WaitForNextTickAsync(token))
+			{
+				try
+				{
+					using var scope = scopes.CreateScope();
+					var sent = await scope.ServiceProvider.GetRequiredService<IFollowService>().ResendPending(DateTime.UtcNow, token);
+					if (sent > 0)
+						logger.LogInformation("Sent {Count} unanswered follow requests again", sent);
+				}
+				catch (Exception ex) when (ex is not OperationCanceledException)
+				{
+					logger.LogWarning(ex, "Unanswered follow requests could not be sent again");
+				}
+			}
+		}
+	}
+}

PrivaPub/Domain/Social/FollowService.cs

@@ -29,6 +29,7 @@ namespace PrivaPub.Domain.Social
 		Task<Following> FollowAs(LocalActor follower, string target, bool showReblogs, CancellationToken token);
 		Task UnfollowAs(LocalActor follower, string target, CancellationToken token);
 		Task<bool> Decide(LocalActor me, string followerAccountId, bool accept, CancellationToken token);
+		Task<int> ResendPending(DateTime now, CancellationToken token);
 	}
 
 	public class FollowService : IFollowService
@@ -95,7 +96,7 @@ namespace PrivaPub.Domain.Social
 			var (local, remote) = await ResolveTarget(target, token);
 			if (local == default && remote == default)
 				return default;
-			if (local != default && (local.Id == follower.Id || !local.IsFederated || local.IsCircle || local.Kind == LocalActorKind.Application))
+			if (local != default && (local.Id == follower.Id || !local.IsFederated || local.IsCircle || local.IsServerActor))
 				return default;
 
 			var targetUri = local?.Uri ?? remote.ActorURI;
@@ -105,6 +106,11 @@ namespace PrivaPub.Domain.Social
 				if (existing.ShowReblogs != showReblogs)
 					await DB.Default.Update<Following>().MatchID(existing.ID).Modify(f => f.ShowReblogs, showReblogs).ExecuteAsync(token);
 				existing.ShowReblogs = showReblogs;
+				// a request still unanswered is sent again, at most once an hour: a server can take a Follow (202) and
+				// drop it later, as one that cannot yet read our actor does; one that holds it already ignores the copy
+				if (existing.State == FollowState.Requested && remote != default)
+					await _delivery.Enqueue(follower, new[] { remote.InboxURL }, FollowActivity(follower, existing), token,
+						again: "again-" + DateTime.UtcNow.ToString("yyyyMMddHH", System.Globalization.CultureInfo.InvariantCulture));
 				return existing;
 			}
 
@@ -128,6 +134,8 @@ namespace PrivaPub.Domain.Social
 			{
 				return await _dbEntities.Followings.Match(f => f.AvatarId == follower.Id && f.TargetActorURI == targetUri).ExecuteFirstAsync(token);
 			}
+			//a new follow starts in no list, whatever lists the account was in before a follow that ended without passing here
+			await DB.Default.DeleteAsync<PersonaListMember>(m => m.AvatarId == follower.Id && m.AccountId == following.TargetAccountId);
 
 			if (local != default)
 				await FollowLocally(follower, local, following, token);
@@ -145,6 +153,7 @@ namespace PrivaPub.Domain.Social
 				return;
 
 			await DB.Default.DeleteAsync<Following>(following.ID);
+			await DB.Default.DeleteAsync<PersonaListMember>(m => m.AvatarId == follower.Id && m.AccountId == following.TargetAccountId);
 			if (following.TargetIsLocal)
 			{
 				await DB.Default.DeleteAsync<Follower>(f => f.LocalActorId == following.TargetAccountId && f.ActorURI == follower.Uri);
@@ -268,6 +277,45 @@ namespace PrivaPub.Domain.Social
 			return (default, actorUri == default ? default : await _remoteActors.GetActor(actorUri, refresh: false, token));
 		}
 
+		// how long after it was made, or last sent again, a request still unanswered is sent again: 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
+		// already holds the follow answers the copy again
+		public static readonly TimeSpan[] ResendAfter =
+		{
+			TimeSpan.FromMinutes(15), TimeSpan.FromHours(1), TimeSpan.FromHours(6), TimeSpan.FromDays(1), TimeSpan.FromDays(2), TimeSpan.FromDays(4)
+		};
+
+		// the requests to remote accounts due to be sent again; how many were
+		public async Task<int> ResendPending(DateTime now, CancellationToken token)
+		{
+			var sent = 0;
+			// (a request older than the count has no Resent yet: "not at least" matches it, "less than" would not)
+			var pending = await _dbEntities.Followings.Match(f => f.State == FollowState.Requested && !f.TargetIsLocal && !(f.Resent >= ResendAfter.Length))
+				.ExecuteAsync(token);
+			foreach (var following in pending.Where(f => (f.ResentAt ?? f.CreatedAt) + ResendAfter[f.Resent] <= now))
+			{
+				var follower = await _localActors.FindById(LocalActorKind.Person, following.AvatarId, token);
+				var inbox = following.TargetInboxURL ?? (await _remoteActors.GetActor(following.TargetActorURI, refresh: false, token))?.InboxURL;
+				if (follower != default && !string.IsNullOrEmpty(inbox))
+				{
+					// under a new id each time: Lemmy keeps the ids it received and never answers one again
+					var again = FollowActivity(follower, following);
+					again["id"] = AgainId(following.FollowActivityURI, following.Resent + 1);
+					await _delivery.Enqueue(follower, new[] { inbox }, again, token,
+						again: "resend-" + now.ToString("yyyyMMddHHmm", System.Globalization.CultureInfo.InvariantCulture));
+					sent++;
+				}
+				await DB.Default.Update<Following>().MatchID(following.ID).Modify(b => b.Inc(f => f.Resent, 1)).Modify(f => f.ResentAt, now)
+					.ExecuteAsync(token);
+			}
+			return sent;
+		}
+
+		// a follow sent again is the same follow under a new id, which an answer may name (AcceptHandler.FindFollowing)
+		public const string Again = "-again-";
+
+		public static string AgainId(string followActivityUri, int resend) => $"{followActivityUri}{Again}{resend}";
+
 		static JsonObject FollowActivity(LocalActor follower, Following following) => new()
 		{
 			["@context"] = ActivityPubRenderer.ActivityStreams,

PrivaPub/Domain/Social/NotificationPolicies.cs

@@ -0,0 +1,137 @@
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.Social;
+using PrivaPub.Models.User;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Domain.Social
+{
+	// A persona's notification policy (Mastodon 4.3), applied as each notification is made: accepted, filtered into a
+	// request per account, or dropped. Polls ending and edits of posts the persona answered are never filtered.
+	public static class NotificationPolicies
+	{
+		static readonly TimeSpan NewAccount = TimeSpan.FromDays(30);
+		// someone who followed the persona lately is not yet a follower for the policy: following, then writing, is how
+		// a newcomer gets past it
+		static readonly TimeSpan NewFollower = TimeSpan.FromDays(3);
+
+		public static async Task<NotificationPolicy> Of(string avatarId, CancellationToken token) =>
+			await DB.Default.Find<NotificationPolicy>().Match(p => p.AvatarId == avatarId).ExecuteFirstAsync(token)
+			?? new NotificationPolicy { AvatarId = avatarId };
+
+		public static async Task Save(NotificationPolicy policy, CancellationToken token) =>
+			await DB.Default.Update<NotificationPolicy>().Match(p => p.AvatarId == policy.AvatarId)
+				.Modify(p => p.ForNotFollowing, policy.ForNotFollowing)
+				.Modify(p => p.ForNotFollowers, policy.ForNotFollowers)
+				.Modify(p => p.ForNewAccounts, policy.ForNewAccounts)
+				.Modify(p => p.ForPrivateMentions, policy.ForPrivateMentions)
+				.Modify(p => p.ForLimitedAccounts, policy.ForLimitedAccounts)
+				.Option(o => o.IsUpsert = true)
+				.ExecuteAsync(token);
+
+		public static async Task<NotificationAction> Judge(string avatarId, NotificationType type, string fromAccountId, string fromActorUri, string postId,
+			CancellationToken token)
+		{
+			if (type is NotificationType.Poll or NotificationType.Update || string.IsNullOrEmpty(fromActorUri))
+				return NotificationAction.Accept;
+			var policy = await DB.Default.Find<NotificationPolicy>().Match(p => p.AvatarId == avatarId).ExecuteFirstAsync(token);
+			if (policy is null or { ForNotFollowing: NotificationAction.Accept, ForNotFollowers: NotificationAction.Accept, ForNewAccounts: NotificationAction.Accept,
+				ForPrivateMentions: NotificationAction.Accept, ForLimitedAccounts: NotificationAction.Accept })
+				return NotificationAction.Accept;
+			if (await DB.Default.Find<NotificationPermission>().Match(p => p.AvatarId == avatarId && p.FromActorURI == fromActorUri).ExecuteAnyAsync(token))
+				return NotificationAction.Accept;
+
+			var actions = new List<NotificationAction>();
+			var following = await DB.Default.Find<Following>()
+				.Match(f => f.AvatarId == avatarId && f.TargetActorURI == fromActorUri && f.State == FollowState.Accepted).ExecuteAnyAsync(token);
+			if (!following)
+				actions.Add(policy.ForNotFollowing);
+			if (policy.ForNotFollowers != NotificationAction.Accept)
+			{
+				var since = DateTime.UtcNow - NewFollower;
+				if (!await DB.Default.Find<Follower>()
+					.Match(f => f.LocalActorId == avatarId && f.ActorURI == fromActorUri && f.IsAccepted && f.CreationDate <= since).ExecuteAnyAsync(token))
+					actions.Add(policy.ForNotFollowers);
+			}
+			if (policy.ForNewAccounts != NotificationAction.Accept || policy.ForLimitedAccounts != NotificationAction.Accept)
+			{
+				var (since, silenced) = await Sender(fromAccountId, fromActorUri, token);
+				if (since > DateTime.UtcNow - NewAccount)
+					actions.Add(policy.ForNewAccounts);
+				if (silenced)
+					actions.Add(policy.ForLimitedAccounts);
+			}
+			// a private mention it did not ask for: from someone it does not follow, answering nothing of the persona's
+			if (policy.ForPrivateMentions != NotificationAction.Accept && type == NotificationType.Mention && !following && !string.IsNullOrEmpty(postId)
+				&& await DB.Default.Find<PostEntity>().Match(p => p.ID == postId && p.Visibility == PostVisibility.Direct && p.InReplyToAccountId != avatarId)
+					.ExecuteAnyAsync(token))
+				actions.Add(policy.ForPrivateMentions);
+			return actions.Contains(NotificationAction.Drop) ? NotificationAction.Drop
+				: actions.Contains(NotificationAction.Filter) ? NotificationAction.Filter
+				: NotificationAction.Accept;
+		}
+
+		// since when the sender has been on the fediverse (its actor's published, else when this server first met it), and
+		// whether it is silenced here, itself or its server
+		static async Task<(DateTime Since, bool Silenced)> Sender(string accountId, string actorUri, CancellationToken token)
+		{
+			var host = Uri.TryCreate(actorUri, UriKind.Absolute, out var uri) ? uri.Host : default;
+			var silencedHere = host != default && (await DB.Default.Find<DomainBlock>().Match(b => b.Severity == DomainBlockSeverity.Silence).ExecuteAsync(token))
+				.Any(b => host.Equals(b.Domain, StringComparison.OrdinalIgnoreCase) || host.EndsWith("." + b.Domain, StringComparison.OrdinalIgnoreCase));
+			if (!string.IsNullOrEmpty(accountId) && await DB.Default.Find<Avatar>().Match(a => a.ID == accountId).ExecuteFirstAsync(token) is { } local)
+				return (local.CreatedAt, local.SilencedAt.HasValue);
+			var foreign = await DB.Default.Find<ForeignAvatar>().Match(a => a.ActorURI == actorUri).ExecuteFirstAsync(token);
+			return foreign == default ? (DateTime.UtcNow, silencedHere) : (foreign.Published ?? foreign.CreatedAt, silencedHere || foreign.SilencedAt.HasValue);
+		}
+
+		// a notification filtered from an account: its request gathers it
+		public static async Task Requested(Notification notification, CancellationToken token)
+		{
+			var now = DateTime.UtcNow;
+			var update = DB.Default.Update<NotificationRequest>()
+				.Match(r => r.AvatarId == notification.AvatarId && r.FromActorURI == notification.FromActorURI)
+				.Modify(b => b.Inc(r => r.NotificationsCount, 1))
+				.Modify(r => r.FromAccountId, notification.FromAccountId)
+				.Modify(r => r.UpdatedAt, now)
+				.Modify(b => b.SetOnInsert(r => r.CreatedAt, now))
+				.Option(o => o.IsUpsert = true);
+			if (!string.IsNullOrEmpty(notification.PostId))
+				update.Modify(r => r.LastPostId, notification.PostId);
+			try
+			{
+				await update.ExecuteAsync(token);
+			}
+			catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
+			{
+				// (two filtered at once from one account: the other made the request)
+				await update.Option(o => o.IsUpsert = false).ExecuteAsync(token);
+			}
+		}
+
+		// the persona lets an account's notifications in, now and from then on
+		public static async Task Accept(NotificationRequest request, CancellationToken token)
+		{
+			try
+			{
+				await DB.Default.SaveAsync(new NotificationPermission { AvatarId = request.AvatarId, FromActorURI = request.FromActorURI }, token);
+			}
+			catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
+			{
+			}
+			await DB.Default.Update<Notification>().Match(n => n.AvatarId == request.AvatarId && n.FromActorURI == request.FromActorURI && n.Filtered)
+				.Modify(n => n.Filtered, false).ExecuteAsync(token);
+			await DB.Default.DeleteAsync<NotificationRequest>(request.ID);
+		}
+
+		// or dismisses them
+		public static async Task Dismiss(NotificationRequest request, CancellationToken token)
+		{
+			await DB.Default.DeleteAsync<Notification>(n => n.AvatarId == request.AvatarId && n.FromActorURI == request.FromActorURI && n.Filtered);
+			await DB.Default.DeleteAsync<NotificationRequest>(request.ID);
+		}
+	}
+}

PrivaPub/Domain/Social/Notifications.cs

@@ -14,9 +14,12 @@ namespace PrivaPub.Domain.Social
 				return;
 			if ((await Relationships.Hidden.AuthorsHiddenFrom(avatarId, new[] { fromActorUri }, forNotifications: true, token)).Count > 0)
 				return;
+			var action = await NotificationPolicies.Judge(avatarId, type, fromAccountId, fromActorUri, postId, token);
+			if (action == NotificationAction.Drop)
+				return;
 			try
 			{
-				await DB.Default.SaveAsync(new Notification
+				var notification = new Notification
 				{
 					AvatarId = avatarId,
 					Type = type,
@@ -25,8 +28,19 @@ namespace PrivaPub.Domain.Social
 					PostId = postId,
 					Emoji = emoji,
 					EmojiURL = emojiUrl,
-					DedupeKey = emoji == default ? $"{type}|{avatarId}|{fromActorUri}|{postId}" : $"{type}|{avatarId}|{fromActorUri}|{postId}|{emoji}"
-				}, token);
+					DedupeKey = emoji == default ? $"{type}|{avatarId}|{fromActorUri}|{postId}" : $"{type}|{avatarId}|{fromActorUri}|{postId}|{emoji}",
+					Filtered = action == NotificationAction.Filter
+				};
+				await DB.Default.SaveAsync(notification, token);
+				// filtered: in its account's request, told to no stream
+				if (notification.Filtered)
+				{
+					await NotificationPolicies.Requested(notification, token);
+					return;
+				}
+				var told = new Timelines.Streams.Event("notification", notification.ID);
+				Timelines.Streams.ToPersona(avatarId, new Timelines.Streams.Key(Timelines.Streams.User), told);
+				Timelines.Streams.ToPersona(avatarId, new Timelines.Streams.Key(Timelines.Streams.UserNotification), told);
 			}
 			catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
 			{

PrivaPub/Domain/Social/Reactions.cs

@@ -1,9 +1,9 @@
 using MongoDB.Driver;
 using MongoDB.Entities;
 
+using PrivaPub.Domain.Privacy;
 using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Inbox;
-using PrivaPub.Federation.Inbox.Handlers;
 using PrivaPub.Federation.Objects;
 using PrivaPub.Federation.Outbox;
 using PrivaPub.Federation.Rendering;
@@ -43,9 +43,10 @@ namespace PrivaPub.Domain.Social
 
 		public async Task Receive(PostEntity post, ForeignAvatar actor, string content, JsonNode tags, string activityId, CancellationToken token)
 		{
-			if (!LikeHandler.MaySee(post, actor) || Normalise(content, ObjectShapes.Emojis(tags)) is not { } emoji)
+			var visible = await VisibilityPolicy.RemoteCanSee(post, actor, token);
+			if (!visible || Normalise(content, ObjectShapes.Emojis(tags)) is not { } emoji)
 			{
-				Arrival.Drop(LikeHandler.MaySee(post, actor) ? "unparseable" : "not-visible");
+				Arrival.Drop(visible ? "unparseable" : "not-visible");
 				return;
 			}
 			try
@@ -177,6 +178,11 @@ namespace PrivaPub.Domain.Social
 					return requireKnownCustom ? default : new Picked(bare, default);
 				return new Picked(bare, emoji.URL);
 			}
+			// one emoji, one name: ❤ and ❤️ (with the emoji variation selector) were two reactions, counted apart. The selector
+			// is dropped, then put back on a symbol that shows as text without it (U+2000 to U+2BFF: ❤, ☺, ✌...)
+			text = text.Replace("\uFE0F", "");
+			if (text.Length == 1 && text[0] is >= '\u2000' and <= '\u2BFF')
+				text += "\uFE0F";
 			if (text.Any(c => c < 128 || char.IsWhiteSpace(c)) || new StringInfo(text).LengthInTextElements != 1)
 				return default;
 			return new Picked(text, default);

PrivaPub/Domain/Social/Trends.cs

@@ -0,0 +1,126 @@
+using Microsoft.Extensions.Caching.Memory;
+
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
+using PrivaPub.StaticServices;
+
+namespace PrivaPub.Domain.Social
+{
+	// What is being talked about here (owner decision 2026-10-04: trends count only public posts PrivaPub already holds,
+	// and fetch nothing). Hashtags and links rise with the number of different authors using them today against the
+	// week before; posts with their favourites, boosts and replies, halving every twelve hours. A post trends only if its
+	// author is discoverable, and nothing warned about (content warning) trends. Computed at most every ten minutes.
+	public sealed class Trends
+	{
+		public static readonly TimeSpan Fresh = TimeSpan.FromMinutes(10);
+		const int MinAuthors = 2;//one account alone never makes a trend
+		const int Kept = 40;
+
+		readonly DbEntities _dbEntities;
+		readonly IMemoryCache _cache;
+
+		public Trends(DbEntities dbEntities, IMemoryCache cache)
+		{
+			_dbEntities = dbEntities;
+			_cache = cache;
+		}
+
+		// what is computed is forgotten: the next read computes it again
+		public void Forget()
+		{
+			foreach (var key in new[] { "trends:tags", "trends:links", "trends:statuses" })
+				_cache.Remove(key);
+		}
+
+		public sealed record DayUse(DateTime Day, int Uses, int Accounts);
+
+		public sealed record Trend(string Key, List<DayUse> History, string SamplePostId);
+
+		public Task<List<Trend>> Tags(CancellationToken token) =>
+			_cache.GetOrCreateAsync("trends:tags", async entry =>
+			{
+				entry.AbsoluteExpirationRelativeToNow = Fresh;
+				var posts = await Week(p => p.Tags.Count > 0, token);
+				return Rank(posts.SelectMany(p => p.Tags.Distinct().Select(t => (Key: t, Post: p))));
+			});
+
+		public Task<List<Trend>> Links(CancellationToken token) =>
+			_cache.GetOrCreateAsync("trends:links", async entry =>
+			{
+				entry.AbsoluteExpirationRelativeToNow = Fresh;
+				var posts = await Week(p => p.Link != null, token);
+				return Rank(posts.Where(p => Uri.TryCreate(p.Link.Href, UriKind.Absolute, out var uri) && uri.Scheme is "https" or "http")
+					.Select(p => (Key: Normal(p.Link.Href), Post: p)));
+			});
+
+		// the ids of the trending posts, best first
+		public Task<List<string>> Statuses(CancellationToken token) =>
+			_cache.GetOrCreateAsync("trends:statuses", async entry =>
+			{
+				entry.AbsoluteExpirationRelativeToNow = Fresh;
+				var now = DateTime.UtcNow;
+				var since = now.AddHours(-48);
+				var posts = await _dbEntities.Posts
+					.Match(p => p.Visibility == PostVisibility.Public && !p.DeletedAt.HasValue && !p.AuthorGone && !p.HasContentWarning && !p.IsLocalOnly
+						&& p.ReblogOfPostId == null && p.InReplyToURI == null && p.AnsweringToPostId == null && p.CreationDate >= since
+						&& p.FavouritesCount + p.ReblogsCount + p.RepliesCount > 0)
+					.ExecuteAsync(token);
+				var discoverable = await Discoverable(posts.Select(p => p.AuthorAccountId ?? p.GroupUserId), token);
+				return posts.Where(p => discoverable.Contains(p.AuthorAccountId ?? p.GroupUserId))
+					.Select(p => (p.ID, Score: (p.FavouritesCount + 2.0 * p.ReblogsCount + p.RepliesCount) * Math.Pow(0.5, (now - p.CreationDate).TotalHours / 12)))
+					.OrderByDescending(p => p.Score).Take(Kept).Select(p => p.ID).ToList();
+			});
+
+		Task<List<Post>> Week(System.Linq.Expressions.Expression<Func<Post, bool>> with, CancellationToken token)
+		{
+			var since = DateTime.UtcNow.Date.AddDays(-6);
+			return _dbEntities.Posts
+				.Match(p => p.Visibility == PostVisibility.Public && !p.DeletedAt.HasValue && !p.AuthorGone && !p.HasContentWarning && !p.IsLocalOnly
+					&& p.ReblogOfPostId == null && p.CreationDate >= since)
+				.Match(with)
+				.Project(p => p.Include(x => x.ID).Include(x => x.Tags).Include(x => x.Link).Include(x => x.CreationDate)
+					.Include(x => x.AuthorAccountId).Include(x => x.GroupUserId))
+				.ExecuteAsync(token);
+		}
+
+		// rising: today's authors squared over the week's daily average before today, so a new subject beats a steady one
+		static List<Trend> Rank(IEnumerable<(string Key, Post Post)> uses)
+		{
+			var today = DateTime.UtcNow.Date;
+			return uses.GroupBy(u => u.Key)
+				.Select(g =>
+				{
+					var history = Enumerable.Range(0, 7).Select(back => today.AddDays(-back)).Select(day =>
+					{
+						var that = g.Where(u => u.Post.CreationDate >= day && u.Post.CreationDate < day.AddDays(1)).ToList();
+						return new DayUse(day, that.Count, that.Select(u => u.Post.AuthorAccountId ?? u.Post.GroupUserId).Distinct().Count());
+					}).ToList();
+					var recentAuthors = g.Where(u => u.Post.CreationDate >= today.AddDays(-1)).Select(u => u.Post.AuthorAccountId ?? u.Post.GroupUserId).Distinct().Count();
+					var before = history.Skip(1).Average(h => h.Accounts);
+					return (Trend: new Trend(g.Key, history, g.OrderByDescending(u => u.Post.CreationDate).First().Post.ID),
+						Recent: recentAuthors, Score: recentAuthors * recentAuthors / (before + 1));
+				})
+				.Where(t => t.Recent >= MinAuthors)
+				.OrderByDescending(t => t.Score).ThenByDescending(t => t.Recent).ThenBy(t => t.Trend.Key, StringComparer.Ordinal)
+				.Take(Kept).Select(t => t.Trend).ToList();
+		}
+
+		static string Normal(string href) =>
+			Uri.TryCreate(href, UriKind.Absolute, out var uri) ? uri.GetLeftPart(UriPartial.Query).TrimEnd('/') : href;
+
+		// the accounts among these whose owners let them be discovered: personas by their setting, remote accounts by theirs
+		static async Task<HashSet<string>> Discoverable(IEnumerable<string> accountIds, CancellationToken token)
+		{
+			var ids = accountIds.Where(id => !string.IsNullOrEmpty(id)).Distinct().ToList();
+			var barred = await Privacy.Counted.BarredPersonas(token);
+			var local = await DB.Default.Find<Avatar>().Match(a => ids.Contains(a.ID) && a.Settings.IsDiscoverable && !a.DeletionAt.HasValue && !barred.Contains(a.ID))
+				.Project(a => a.Include(x => x.ID)).ExecuteAsync(token);
+			var remote = await DB.Default.Find<ForeignAvatar>().Match(f => ids.Contains(f.ID) && f.IsDiscoverable && !f.DeletionAt.HasValue && !f.SuspendedAt.HasValue)
+				.Project(f => f.Include(x => x.ID)).ExecuteAsync(token);
+			return local.Select(a => a.ID).Concat(remote.Select(f => f.ID)).ToHashSet();
+		}
+	}
+}

PrivaPub/Domain/Statistics/StatisticsQueries.cs

@@ -1,5 +1,6 @@
 using MongoDB.Entities;
 
+using PrivaPub.ClientModels.Admin;
 using PrivaPub.Infrastructure.Statistics;
 using PrivaPub.Models.Jobs;
 using PrivaPub.Models.Statistics;
@@ -46,7 +47,7 @@ namespace PrivaPub.Domain.Statistics
 			return result.OrderBy(d => d.Day).ThenBy(d => d.Host, StringComparer.Ordinal).ToList();
 		}
 
-		public async Task<object> Overview(int days, CancellationToken token)
+		public async Task<ViewStatisticsOverview> Overview(int days, CancellationToken token)
 		{
 			var hostDays = await Days(days, default, token);
 			var counters = Sum(hostDays.Select(d => d.Counters));
@@ -54,21 +55,21 @@ namespace PrivaPub.Domain.Statistics
 			var server = await DB.Default.Find<ServerDay>().Match(d => d.Day >= DateTime.UtcNow.Date.AddDays(1 - Math.Clamp(days, 1, 3660))).ExecuteAsync(token);
 			var delivered = Outcomes(counters, Interactions.Out);
 			var attempts = delivered.Where(o => o.Key != Interactions.Deferred).Sum(o => o.Value);
-			return new
+			return new ViewStatisticsOverview
 			{
 				Days = days,
 				Channels = Channels.ToDictionary(c => c, c => counters.Where(k => k.Key.StartsWith(c + ":", StringComparison.Ordinal)).Sum(k => k.Value)),
 				Inbound = Outcomes(counters, Interactions.In),
 				Outbound = delivered,
 				DeliverySuccess = attempts == 0 ? (double?)null : Math.Round(delivered.GetValueOrDefault(Interactions.Ok) / (double)attempts, 4),
-				DeliveryLatencyMs = new { P50 = Percentile(latency, Interactions.Out, 0.5), P95 = Percentile(latency, Interactions.Out, 0.95) },
-				Hosts = new
+				DeliveryLatencyMs = new ViewLatency { P50 = Percentile(latency, Interactions.Out, 0.5), P95 = Percentile(latency, Interactions.Out, 0.95) },
+				Hosts = new ViewHostCounts
 				{
 					Active = hostDays.Where(d => d.Host != Interactions.Unknown && d.Counters.Count > 0).Select(d => d.Host).Distinct().Count(),
 					Known = await DB.Default.CountAsync<RemoteInstance>(cancellation: token)
 				},
 				Accounts = server.Sum(d => d.Accounts) + hostDays.Where(d => d.Live).Sum(d => d.Accounts),
-				Ledger = new
+				Ledger = new ViewLedgerCounts
 				{
 					Written = server.Sum(d => d.LedgerWritten),
 					Dropped = server.Sum(d => d.LedgerDropped),
@@ -77,7 +78,7 @@ namespace PrivaPub.Domain.Statistics
 			};
 		}
 
-		public async Task<object> Hosts(int days, string sort, string software, int page, int limit, CancellationToken token)
+		public async Task<ViewHostsPage> Hosts(int days, string sort, string software, int page, int limit, CancellationToken token)
 		{
 			var hostDays = await Days(days, default, token);
 			var instances = (await DB.Default.Find<RemoteInstance>().ExecuteAsync(token)).ToDictionary(i => i.Host, StringComparer.Ordinal);
@@ -87,10 +88,10 @@ namespace PrivaPub.Domain.Statistics
 					var counters = Sum(g.Select(d => d.Counters));
 					var outbound = Outcomes(counters, Interactions.Out);
 					var instance = instances.GetValueOrDefault(g.Key);
-					return new
+					return new ViewHostRow
 					{
 						Host = g.Key,
-						instance?.Software,
+						Software = instance?.Software,
 						Version = instance?.SoftwareVersion,
 						In = counters.Where(k => k.Key.StartsWith("in:", StringComparison.Ordinal)).Sum(k => k.Value),
 						Out = counters.Where(k => k.Key.StartsWith("out:", StringComparison.Ordinal)).Sum(k => k.Value),
@@ -98,8 +99,12 @@ namespace PrivaPub.Domain.Statistics
 						Failures = outbound.Where(o => o.Key is Interactions.Retry or Interactions.Dead or Interactions.Failed).Sum(o => o.Value),
 						LatencyP50 = Percentile(Sum(g.Select(d => d.Latency)), Interactions.Out, 0.5),
 						Accounts = g.Sum(d => d.Accounts),
-						instance?.DescribedAt,
-						Delivery = instance == default ? default : new { instance.ConsecutiveFailures, instance.UnavailableUntil, instance.LastSuccessAt, instance.LastFailureAt }
+						DescribedAt = instance?.DescribedAt,
+						Delivery = instance == default ? default : new ViewHostDelivery
+						{
+							ConsecutiveFailures = instance.ConsecutiveFailures, UnavailableUntil = instance.UnavailableUntil, LastSuccessAt = instance.LastSuccessAt,
+							LastFailureAt = instance.LastFailureAt
+						}
 					};
 				})
 				.Where(r => software == default || string.Equals(r.Software, software, StringComparison.OrdinalIgnoreCase));
@@ -112,7 +117,7 @@ namespace PrivaPub.Domain.Statistics
 			};
 			var list = rows.ToList();
 			limit = Math.Clamp(limit, 1, 200);
-			return new { Total = list.Count, Page = Math.Max(page, 1), Hosts = list.Skip((Math.Max(page, 1) - 1) * limit).Take(limit), Attribution };
+			return new ViewHostsPage { Total = list.Count, Page = Math.Max(page, 1), Hosts = list.Skip((Math.Max(page, 1) - 1) * limit).Take(limit).ToList(), Attribution = Attribution };
 		}
 
 		public async Task<object> Host(string host, int days, CancellationToken token)
@@ -147,7 +152,7 @@ namespace PrivaPub.Domain.Statistics
 				.ExecuteAsync(token);
 		}
 
-		public async Task<object> Crawler(bool enabled, int revisitDays, CancellationToken token)
+		public async Task<ViewCrawler> Crawler(bool enabled, int revisitDays, CancellationToken token)
 		{
 			var due = DateTime.UtcNow.AddDays(-Math.Max(revisitDays, 1));
 			var recent = await DB.Default.Find<RemoteInstance>()
@@ -155,14 +160,18 @@ namespace PrivaPub.Domain.Statistics
 				.Sort(i => i.LastCrawledAt, Order.Descending)
 				.Limit(20)
 				.ExecuteAsync(token);
-			return new
+			return new ViewCrawler
 			{
 				Enabled = enabled,
 				Touched = await DB.Default.CountAsync<RemoteInstance>(i => i.Seen == "touched", token),
 				Crawled = await DB.Default.CountAsync<RemoteInstance>(i => i.Seen == "crawled", token),
 				Due = await DB.Default.CountAsync<RemoteInstance>(i => i.LastCrawledAt == null || i.LastCrawledAt < due, token),
 				RobotsDisallowed = await DB.Default.CountAsync<RemoteInstance>(i => i.RobotsDisallowed == true, token),
-				Recent = recent.Select(i => new { i.Host, i.Seen, i.LastCrawledAt, i.PeersCount, i.RobotsDisallowed, i.CrawlError, i.Software })
+				Recent = recent.Select(i => new ViewCrawledHost
+				{
+					Host = i.Host, Seen = i.Seen, LastCrawledAt = i.LastCrawledAt, PeersCount = i.PeersCount, RobotsDisallowed = i.RobotsDisallowed,
+					CrawlError = i.CrawlError, Software = i.Software
+				}).ToList()
 			};
 		}
 

PrivaPub/Domain/Statuses/ConversationStates.cs

@@ -0,0 +1,59 @@
+using MongoDB.Driver;
+using MongoDB.Entities;
+
+using PrivaPub.Models.Group;
+using PrivaPub.Models.Social;
+
+namespace PrivaPub.Domain.Statuses
+{
+	// A direct conversation's newest post (DmGroup.LastPostId, which pages the conversations list) and each persona's
+	// read and removed marks on it (ConversationState). A conversation is unread for a persona when its newest post is
+	// someone else's and newer than what the persona read; writing in it reads it.
+	public static class ConversationStates
+	{
+		public static async Task Posted(string conversationId, string postId, string authorAvatarId, CancellationToken token)
+		{
+			await DB.Default.Update<DmGroup>().MatchID(conversationId)
+				.Modify(g => g.UpdatedAt, DateTime.UtcNow)
+				.Modify(g => g.LastPostId, postId)
+				.ExecuteAsync(token);
+			if (authorAvatarId != default)
+				await Read(authorAvatarId, conversationId, postId, token);
+		}
+
+		public static Task Read(string avatarId, string conversationId, string postId, CancellationToken token) =>
+			Mark(avatarId, conversationId, s => s.LastReadPostId, postId, token);
+
+		public static Task Hide(string avatarId, string conversationId, string postId, CancellationToken token) =>
+			Mark(avatarId, conversationId, s => s.HiddenUpTo, postId, token);
+
+		public static bool IsUnread(ConversationState state, string lastPostId, string lastAuthorId, string avatarId) =>
+			lastPostId != default && lastAuthorId != avatarId && string.CompareOrdinal(lastPostId, state?.LastReadPostId) > 0;
+
+		public static bool IsHidden(ConversationState state, string lastPostId) =>
+			state?.HiddenUpTo != default && string.CompareOrdinal(lastPostId, state.HiddenUpTo) <= 0;
+
+		// the mark only moves forward; the first mark makes the state (two at once: the unique index keeps one, and the
+		// loser marks again)
+		static async Task Mark(string avatarId, string conversationId, System.Linq.Expressions.Expression<Func<ConversationState, string>> field,
+			string postId, CancellationToken token)
+		{
+			if (postId == default)
+				return;
+			Task Write() => DB.Default.Update<ConversationState>()
+				.Match(s => s.AvatarId == avatarId && s.ConversationId == conversationId)
+				.Modify(b => b.Max(field, postId))
+				.Modify(s => s.UpdatedAt, DateTime.UtcNow)
+				.Option(o => o.IsUpsert = true)
+				.ExecuteAsync(token);
+			try
+			{
+				await Write();
+			}
+			catch (MongoWriteException ex) when (ex.WriteError?.Category == ServerErrorCategory.DuplicateKey)
+			{
+				await Write();
+			}
+		}
+	}
+}