Everything on, phase 4a: one answer everywhere for counts, search, collections and the instance API

Owner decision 2026-10-04: fix the mismatches and every other mismatch of the same kind.

- One counting rule (Domain/Privacy/Counted), Mastodon's. It is used for a persona's statuses_count, its outbox
  totalItems, NodeInfo localPosts and the instance status_count, which used to count four different things. It
  counts every post that is neither deleted nor a DM, boosts included, and circle and located posts too (owner
  decision). A group's count includes its remote members' posts.
- Users. Personas of banned or deleted roots no longer count, and are not found in search. NodeInfo now gives
  activeMonth and activeHalfyear, and the v2 instance gives active_month instead of a constant 0.
- replies_count counts only public and unlisted replies, so it no longer tells anyone that a private reply exists.
  Migration _012 recounts it.
- A remote account that deletes itself takes everything out of every count (GoneActors): its likes, downvotes,
  reactions and poll votes go and their counters come back, as do its boosts', replies' and quotes' counts, and its
  notifications. Lookups, account lists, search and favourited_by no longer show it. Migration _012 applies this to
  accounts already gone.
- Deleting a post also deletes its pins and the local boosts of it.
- /stalking gives the same total as following_count. Members are still never listed, and hide_collections is now
  always true, since the setting never did anything.
- Joining a community by invitation is following it, so /flock and /groupies agree; leaving unfollows.
- Search. Anyone may search, as on Mastodon; resolve and offset need a sign-in, offset pages, and deleted accounts
  are never found.
- notifications/unread_count counts what the list shows, and the owner's follower and following lists page with
  Link.
- The instance API advertises what is enforced:
  - max_characters, now enforced with a 422;
  - max_pinned_statuses = MaxPins;
  - the media types and limits MediaService and MediaOptions accept;
  - PollService's limits;
  - the configured languages;
  - no streaming URL until streaming exists.

  domain_count counts the servers we have exchanged with; which ones stays unpublished (peers is empty).
- Routes Mastodon answers now answer instead of 404:
  - directory, tags/{name}, timelines/link and identity_proofs;
  - instance/languages, translation_languages, domain_blocks and privacy_policy;
  - the v1 and v2 notification policy, and notification requests.

Also, from phase 3: a recovered password ends /clientapi sessions through a per-root SessionStamp claim instead of
comparing the JWT's whole-second nbf with the change time. That comparison let a token issued in the same second
survive, which made a test flaky.

671 tests pass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ELjqpznMFMNrJoJUj6K5p2

PrivaPub/Domain/Media/MediaService.cs

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

PrivaPub/Domain/Privacy/Counted.cs

@@ -0,0 +1,73 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
+
+using System.Linq.Expressions;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Domain.Privacy
+{
+	// What the numbers count, in one place, so a persona's statuses_count, its outbox's totalItems, NodeInfo and the
+	// instance API agree (they used to count four different things).
+	public static class Counted
+	{
+		// Mastodon's statuses_count: every post that is neither deleted nor a direct message, reblogs included. Circle and
+		// located posts count too (owner decision 2026-10-04: "a good balance for the fediverse to work").
+		public static readonly Expression<Func<PostEntity, bool>> Post = p => !p.DeletedAt.HasValue && p.Visibility != PostVisibility.Direct;
+
+		// a persona's own posts, or every post in a group, its remote members' included
+		public static Expression<Func<PostEntity, bool>> By(LocalActor actor)
+		{
+			var id = actor.Id;
+			return actor.Kind == LocalActorKind.Group
+				? p => p.GroupId == id && !p.DeletedAt.HasValue && p.Visibility != PostVisibility.Direct
+				: p => p.GroupUserId == id && !p.IsFederatedCopy && !p.DeletedAt.HasValue && p.Visibility != PostVisibility.Direct;
+		}
+
+		// replies_count counts only public and unlisted replies, as Mastodon does: a count must not tell anyone that a
+		// followers-only, direct or circle reply exists
+		public static bool Reply(PostEntity reply) => reply.Visibility is PostVisibility.Public or PostVisibility.Unlisted;
+
+		public static async Task<long> PostsBy(LocalActor actor, CancellationToken token) =>
+			await DB.Default.CountAsync(By(actor), token);
+
+		// Personas that do not count as this server's users, and are not found in search: those of a banned or deleted root.
+		public static async Task<List<string>> BarredPersonas(CancellationToken token)
+		{
+			var roots = (await DB.Default.Find<RootUser>().Match(u => u.IsBanned || u.DeletedAt != null).Project(u => u.Include(x => x.ID)).ExecuteAsync(token))
+				.Select(u => u.ID).ToList();
+			return roots.Count == 0
+				? new List<string>()
+				: (await DB.Default.Find<RootToAvatar>().Match(ra => roots.Contains(ra.RootId)).ExecuteAsync(token)).Select(ra => ra.AvatarId).ToList();
+		}
+
+		public static async Task<long> Users(CancellationToken token)
+		{
+			var barred = await BarredPersonas(token);
+			return await DB.Default.CountAsync<Avatar>(a => !a.DeletionAt.HasValue && !barred.Contains(a.ID), token);
+		}
+
+		// users who posted within the last days, as NodeInfo's activeMonth and activeHalfyear and the instance API mean it
+		public static async Task<long> ActiveUsers(int days, CancellationToken token)
+		{
+			var barred = await BarredPersonas(token);
+			var since = DateTime.UtcNow.AddDays(-days);
+			var authors = await DB.Default.Find<PostEntity, string>()
+				.Match(p => !p.IsFederatedCopy && p.CreationDate >= since && !barred.Contains(p.GroupUserId))
+				.Project(p => p.GroupUserId)
+				.ExecuteAsync(token);
+			var distinct = authors.Where(a => !string.IsNullOrEmpty(a)).Distinct().ToList();
+			return distinct.Count == 0 ? 0 : await DB.Default.CountAsync<Avatar>(a => distinct.Contains(a.ID) && !a.DeletionAt.HasValue, token);
+		}
+
+		public static async Task<long> LocalPosts(CancellationToken token)
+		{
+			var barred = await BarredPersonas(token);
+			return await DB.Default.CountAsync<PostEntity>(f => f.Where(p => !p.IsFederatedCopy && !barred.Contains(p.GroupUserId)) & f.Where(Post), token);
+		}
+	}
+}

PrivaPub/Domain/Statuses/StatusService.cs

@@ -95,8 +95,17 @@ namespace PrivaPub.Domain.Statuses
 			_fanout = fanout;
 		}
 
+		public const int MaxCharacters = 5000;//what the instance API advertises as max_characters, and enforced here
+
+		static StatusOutcome TooLong(StatusDraft draft) =>
+			(draft.Text?.Length ?? 0) > MaxCharacters
+				? StatusOutcome.Fail(StatusCodes.Status422UnprocessableEntity, $"Validation failed: Text character limit of {MaxCharacters} exceeded")
+				: default;
+
 		public async Task<StatusOutcome> Publish(LocalActor author, StatusDraft draft, CancellationToken token)
 		{
+			if (TooLong(draft) is { } tooLong)
+				return tooLong;
 			var media = await Media(author, draft.MediaIds, default, token);
 			if (media == default)
 				return StatusOutcome.Fail(StatusCodes.Status422UnprocessableEntity, "Validation failed: Media attachments are invalid");
@@ -239,7 +248,7 @@ namespace PrivaPub.Domain.Statuses
 
 			await DB.Default.SaveAsync(post, token);
 			await Attach(media, post.ID, token);
-			if (parent != default)
+			if (parent != default && Counted.Reply(post))
 				await DB.Default.Update<PostEntity>().MatchID(parent.ID).Modify(b => b.Inc(p => p.RepliesCount, 1)).ExecuteAsync(token);
 			await _fanout.Distribute(post, token);
 			await _polls.Scheduled(post, token);
@@ -260,6 +269,8 @@ namespace PrivaPub.Domain.Statuses
 			var post = await Own(author, postId, token);
 			if (post == default)
 				return StatusOutcome.Fail(StatusCodes.Status404NotFound, "Record not found");
+			if (TooLong(draft) is { } tooLong)
+				return tooLong;
 			var media = draft.MediaIds == default ? default : await Media(author, draft.MediaIds, post.ID, token);
 			if (draft.MediaIds != default && media == default)
 				return StatusOutcome.Fail(StatusCodes.Status422UnprocessableEntity, "Validation failed: Media attachments are invalid");
@@ -342,8 +353,12 @@ namespace PrivaPub.Domain.Statuses
 				.Modify(p => p.Revisions, new List<PostRevision>())
 				.ExecuteAsync(token);
 			await DB.Default.DeleteAsync<TimelineEntry>(e => e.PostId == post.ID || e.ReblogOfPostId == post.ID);
-			if (!string.IsNullOrEmpty(post.AnsweringToPostId))
+			// boosts of it end with it, as on Mastodon, so no count keeps them
+			await DB.Default.Update<PostEntity>().Match(p => p.ReblogOfPostId == post.ID && !p.DeletedAt.HasValue)
+				.Modify(p => p.DeletedAt, DateTime.UtcNow).ExecuteAsync(token);
+			if (!string.IsNullOrEmpty(post.AnsweringToPostId) && Counted.Reply(post))
 				await DB.Default.Update<PostEntity>().MatchID(post.AnsweringToPostId).Modify(b => b.Inc(p => p.RepliesCount, -1)).ExecuteAsync(token);
+			await DB.Default.DeleteAsync<Models.Social.Pin>(p => p.PostId == post.ID);//a deleted post no longer takes a pin
 			if (audience.Count > 0)
 			{
 				var delete = ActivityPubRenderer.Delete(author, post.ObjectURI, $"delete-{post.ID}",