Outbound documents speak Mastodon's dialect under PrivaPub's route names

Local text (Domain/Content/ContentRenderer): Markdig with raw HTML off and
autolinks, or plain text for API clients; then @user and @user@host are
resolved (locally or through WebFinger) into Mastodon's h-card markup and
#tags into hashtag links, skipping code, links and e-mail addresses. A
post stores the result, its mentions and its tags, and is delivered to
the mentioned actors and the parent's author as well as to followers.

Renderer:
- Mastodon's @context (toot, schema PropertyValue, discoverable,
  indexable, blurhash, focalPoint, featured, alsoKnownAs, movedTo) and
  FEP-2c59's webfinger;
- an actor's url is its HTML page, its fields are PropertyValue
  attachments, published is cut to the day and indexable is false;
- a note's content is the stored rendering; a title becomes name and a
  bold first line, a content warning without its own text is summarised
  by the title or "Content warning"; Mention and Hashtag tags, contentMap,
  updated, and to/cc by visibility.

Routes take the agreed names: /groupies, /stalking, /scribbles/{id},
/grunts/{id} (a Create resolves), /whispers/{id} for a DM's context. The
outbox is a collection with a first page, paged by max_id. A browser
asking for an actor or a note is redirected to /@user, and WebFinger's
profile-page points there.

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

PrivaPub.Tests/Domain/ContentRendererTests.cs

@@ -0,0 +1,91 @@
+using PrivaPub.Domain.Content;
+using PrivaPub.Federation.Actors;
+using PrivaPub.Infrastructure.Http;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.User;
+
+using GroupEntity = PrivaPub.Models.Group.Group;
+
+namespace PrivaPub.Tests.Domain
+{
+	public class ContentRendererTests
+	{
+		const string Base = "https://privapub.test";
+		readonly ContentRenderer _renderer = new(new StubLocalActors(), new StubRemoteActors());
+
+		[Fact]
+		public async Task Decorates_local_and_remote_mentions_and_hashtags()
+		{
+			var rendered = await _renderer.Markdown("hello @alice and @bob@m.example about #Fedi **now** <script>x</script>", TestContext.Current.CancellationToken);
+
+			Assert.Contains("<span class=\"h-card\" translate=\"no\"><a href=\"https://privapub.test/peasants/alice\" class=\"u-url mention\"", rendered.Html);
+			Assert.Contains("href=\"https://m.example/@bob\"", rendered.Html);
+			Assert.Contains("href=\"https://privapub.test/tags/fedi\" class=\"mention hashtag\"", rendered.Html);
+			Assert.Contains("<strong>now</strong>", rendered.Html);
+			Assert.DoesNotContain("<script>", rendered.Html);
+			Assert.Equal(new[] { "https://m.example/users/bob", "https://privapub.test/peasants/alice" }, rendered.Mentions.Select(m => m.ActorUri).Order(StringComparer.Ordinal));
+			Assert.Equal("fedi", Assert.Single(rendered.Tags));
+		}
+
+		[Theory]
+		[InlineData("`@alice` in code")]
+		[InlineData("mail me@alice.example")]
+		[InlineData("@nobody is unknown")]
+		[InlineData("see https://x.example/page#alice")]
+		public async Task Leaves_what_is_not_a_mention_alone(string text)
+		{
+			var rendered = await _renderer.Markdown(text, TestContext.Current.CancellationToken);
+
+			Assert.Empty(rendered.Mentions);
+			Assert.DoesNotContain("h-card", rendered.Html);
+		}
+
+		[Theory]
+		[InlineData("issue #123")]
+		[InlineData("it&#39;s fine")]
+		[InlineData("[link](https://x.example/#tag)")]
+		public async Task Leaves_what_is_not_a_hashtag_alone(string text) =>
+			Assert.Empty((await _renderer.Markdown(text, TestContext.Current.CancellationToken)).Tags);
+
+		[Fact]
+		public async Task Renders_plain_text_like_mastodon()
+		{
+			var rendered = await _renderer.PlainText("line one\nline <two>\n\nsee https://x.example/a?b=1. #Tag", TestContext.Current.CancellationToken);
+
+			Assert.Equal("<p>line one<br>line &lt;two&gt;</p><p>see <a href=\"https://x.example/a?b=1\" rel=\"nofollow noopener noreferrer\" target=\"_blank\">https://x.example/a?b=1</a>. "
+				+ "<a href=\"https://privapub.test/tags/tag\" class=\"mention hashtag\" rel=\"nofollow noopener noreferrer\" target=\"_blank\">#<span>Tag</span></a></p>", rendered.Html);
+		}
+
+		sealed class StubLocalActors : ILocalActorService
+		{
+			public string BaseAddress => Base;
+
+			public Task<LocalActor> FindByUserName(string userName, CancellationToken token) =>
+				Task.FromResult(userName.Equals("alice", StringComparison.OrdinalIgnoreCase)
+					? new LocalActor { Id = "a1", UserName = "alice", BaseAddress = Base, Kind = LocalActorKind.Person }
+					: default);
+
+			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> GetInstanceActor(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();
+			public LocalActor FromGroup(GroupEntity group) => throw new NotSupportedException();
+		}
+
+		sealed class StubRemoteActors : IRemoteActorService
+		{
+			public Task<string> ResolveHandle(string handle, CancellationToken token) =>
+				Task.FromResult(handle == "bob@m.example" ? "https://m.example/users/bob" : default);
+
+			public Task<ForeignAvatar> GetActor(string actorUri, bool refresh, CancellationToken token) =>
+				Task.FromResult(actorUri == "https://m.example/users/bob"
+					? new ForeignAvatar { ID = "f1", ActorURI = actorUri, UserName = "bob", Url = "https://m.example/@bob", InboxURL = actorUri + "/inbox" }
+					: default);
+
+			public Task<FetchedJson> FetchObject(string uri, CancellationToken token) => throw new NotSupportedException();
+			public Task<ForeignAvatar> GetActorByKeyId(string keyId, bool refresh, CancellationToken token) => throw new NotSupportedException();
+		}
+	}
+}

PrivaPub.Tests/Federation/RendererTests.cs

@@ -0,0 +1,103 @@
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Rendering;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Tests.Federation
+{
+	public class RendererTests
+	{
+		static readonly LocalActor Alice = new()
+		{
+			Id = "a1",
+			Kind = LocalActorKind.Person,
+			UserName = "alice",
+			Name = "Alice",
+			Summary = "I **like** <b>cats</b>",
+			PublicKeyPem = Keys.NewKeyPair().PublicKeyPem,
+			Published = new DateTime(2026, 9, 30, 17, 45, 12, DateTimeKind.Utc),
+			Fields = new Dictionary<string, string> { ["site"] = "https://alice.example", ["mood"] = "<i>ok</i>" },
+			BaseAddress = "https://privapub.test"
+		};
+
+		[Fact]
+		public void An_actor_looks_like_a_mastodon_actor_with_our_route_names()
+		{
+			var actor = ActivityPubRenderer.Actor(Alice);
+
+			Assert.Equal("https://privapub.test/peasants/alice", actor["id"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/@alice", actor["url"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/peasants/alice/mouth", actor["inbox"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/peasants/alice/anus", actor["outbox"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/peasants/alice/groupies", actor["followers"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/peasants/alice/stalking", actor["following"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/human-centipede", actor["endpoints"]!["sharedInbox"]!.GetValue<string>());
+			Assert.Equal("2026-09-30T00:00:00Z", actor["published"]!.GetValue<string>());
+			Assert.Equal("alice@privapub.test", actor["webfinger"]!.GetValue<string>());
+			Assert.False(actor["indexable"]!.GetValue<bool>());
+			Assert.Equal("<p>I <strong>like</strong> &lt;b&gt;cats&lt;/b&gt;</p>", actor["summary"]!.GetValue<string>());
+			var fields = actor["attachment"]!.AsArray();
+			Assert.Contains("rel=\"nofollow noopener noreferrer me\"", fields[0]!["value"]!.GetValue<string>());
+			Assert.Equal("&lt;i&gt;ok&lt;/i&gt;", fields[1]!["value"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/peasants/alice#main-key", actor["publicKey"]!["id"]!.GetValue<string>());
+			Assert.Equal(actor["id"]!.GetValue<string>(), actor["publicKey"]!["owner"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public void A_titled_post_with_a_warning_keeps_the_title_visible_on_mastodon()
+		{
+			var post = new Post
+			{
+				ID = "p1",
+				Title = "On <cats>",
+				ContentHtml = "<p>body</p>",
+				HasContentWarning = true,
+				Language = "en",
+				Mentions = new() { new PostMention { ActorURI = "https://m.example/users/bob", Handle = "@bob@m.example" } },
+				Tags = new() { "cats" },
+				CreationDate = new DateTime(2026, 9, 30, 17, 45, 12, DateTimeKind.Utc)
+			};
+
+			var note = ActivityPubRenderer.Note(post, Alice, default, "https://m.example/users/bob/statuses/1");
+
+			Assert.Equal("https://privapub.test/peasants/alice/scribbles/p1", note["id"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/@alice/p1", note["url"]!.GetValue<string>());
+			Assert.Equal("<p><strong>On &lt;cats&gt;</strong></p><p>body</p>", note["content"]!.GetValue<string>());
+			Assert.Equal("On <cats>", note["summary"]!.GetValue<string>());
+			Assert.True(note["sensitive"]!.GetValue<bool>());
+			Assert.Equal("2026-09-30T17:45:12Z", note["published"]!.GetValue<string>());
+			Assert.Equal(new[] { ActivityPubRenderer.Public }, note["to"]!.AsArray().Select(n => n!.GetValue<string>()));
+			Assert.Equal(new[] { Alice.Followers, "https://m.example/users/bob" }, note["cc"]!.AsArray().Select(n => n!.GetValue<string>()));
+			var tags = note["tag"]!.AsArray();
+			Assert.Equal("@bob@m.example", tags[0]!["name"]!.GetValue<string>());
+			Assert.Equal("https://privapub.test/tags/cats", tags[1]!["href"]!.GetValue<string>());
+			Assert.Equal("https://m.example/users/bob/statuses/1", note["inReplyTo"]!.GetValue<string>());
+			Assert.NotNull(note["contentMap"]!["en"]);
+		}
+
+		[Fact]
+		public void A_warning_without_a_title_or_spoiler_gets_a_generic_summary()
+		{
+			var note = ActivityPubRenderer.Note(new Post { ID = "p2", ContentHtml = "<p>x</p>", HasContentWarning = true }, Alice, default, default);
+
+			Assert.Equal(ActivityPubRenderer.ContentWarning, note["summary"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public void A_direct_note_is_addressed_to_its_recipients_only()
+		{
+			var post = new Post { ID = "p3", ContentHtml = "<p>psst</p>", Visibility = PostVisibility.Direct };
+
+			var note = ActivityPubRenderer.DirectNote(post, Alice, new[] { ("https://m.example/users/bob", "bob@m.example") },
+				Alice.ConversationUri("c1"));
+
+			Assert.Equal(new[] { "https://m.example/users/bob" }, note["to"]!.AsArray().Select(n => n!.GetValue<string>()));
+			Assert.Empty(note["cc"]!.AsArray());
+			Assert.Equal("https://privapub.test/peasants/alice/whispers/c1", note["context"]!.GetValue<string>());
+			Assert.StartsWith("<p><span class=\"h-card\"", note["content"]!.GetValue<string>());
+			Assert.Equal("Mention", note["tag"]![0]!["type"]!.GetValue<string>());
+		}
+	}
+}

PrivaPub/Domain/Content/ContentRenderer.cs

@@ -0,0 +1,150 @@
+using AngleSharp.Dom;
+using AngleSharp.Html.Parser;
+
+using Markdig;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Objects;
+using PrivaPub.Models.Federation;
+
+using System.Net;
+using System.Text.RegularExpressions;
+
+namespace PrivaPub.Domain.Content
+{
+	public sealed record ResolvedMention(string ActorUri, string UserName, string Domain, string ProfileUrl, bool IsLocal, string AccountId, string Inbox)
+	{
+		public string Handle => $"{UserName}@{Domain}";
+	}
+
+	public sealed record RenderedContent(string Html, IReadOnlyList<ResolvedMention> Mentions, IReadOnlyList<string> Tags);
+
+	public interface IContentRenderer
+	{
+		Task<RenderedContent> Markdown(string text, CancellationToken token);
+		Task<RenderedContent> PlainText(string text, CancellationToken token);
+		string TagUrl(string tag);
+	}
+
+	public partial class ContentRenderer : IContentRenderer
+	{
+		const int MaxMentions = 20;
+		static readonly MarkdownPipeline Pipeline = new MarkdownPipelineBuilder().DisableHtml().UseAutoLinks().UseEmphasisExtras().Build();
+		static readonly HtmlParser Parser = new();
+
+		readonly ILocalActorService _localActors;
+		readonly IRemoteActorService _remoteActors;
+
+		public ContentRenderer(ILocalActorService localActors, IRemoteActorService remoteActors)
+		{
+			_localActors = localActors;
+			_remoteActors = remoteActors;
+		}
+
+		public string TagUrl(string tag) => $"{_localActors.BaseAddress}/tags/{Uri.EscapeDataString(tag)}";
+
+		public Task<RenderedContent> Markdown(string text, CancellationToken token) =>
+			Decorate(string.IsNullOrWhiteSpace(text) ? string.Empty : Markdig.Markdown.ToHtml(text, Pipeline), token);
+
+		public Task<RenderedContent> PlainText(string text, CancellationToken token)
+		{
+			if (string.IsNullOrWhiteSpace(text))
+				return Decorate(string.Empty, token);
+			var paragraphs = Regex.Split(text.Replace("\r\n", "\n").Trim(), "\n{2,}")
+				.Select(p => "<p>" + Linkify(WebUtility.HtmlEncode(p)).Replace("\n", "<br>") + "</p>");
+			return Decorate(string.Concat(paragraphs), token);
+		}
+
+		async Task<RenderedContent> Decorate(string html, CancellationToken token)
+		{
+			var document = Parser.ParseDocument($"<body>{html}</body>");
+			var textNodes = document.Body.Descendants<IText>()
+				.Where(node => !node.Ancestors<IElement>().Any(e => e.LocalName is "a" or "code" or "pre"))
+				.ToList();
+
+			var handles = textNodes.SelectMany(node => MentionPattern().Matches(node.Data).Select(m => m.Value))
+				.Distinct(StringComparer.OrdinalIgnoreCase)
+				.Take(MaxMentions)
+				.ToList();
+			var mentions = new Dictionary<string, ResolvedMention>(StringComparer.OrdinalIgnoreCase);
+			foreach (var handle in handles)
+			{
+				var resolved = await Resolve(handle, token);
+				if (resolved != default)
+					mentions[handle] = resolved;
+			}
+
+			var tags = new List<string>();
+			foreach (var node in textNodes)
+			{
+				var replaced = Replace(node.Data, mentions, tags);
+				if (replaced == default)
+					continue;
+				var fragment = Parser.ParseFragment(replaced, node.ParentElement);
+				foreach (var child in fragment.ToList())
+					node.Parent.InsertBefore(child, node);
+				node.Parent.RemoveChild(node);
+			}
+
+			return new RenderedContent(
+				ContentSanitizer.Html(document.Body.InnerHtml),
+				mentions.Values.DistinctBy(m => m.ActorUri).ToList(),
+				tags.Distinct().ToList());
+		}
+
+		string Replace(string text, IReadOnlyDictionary<string, ResolvedMention> mentions, List<string> tags)
+		{
+			var changed = false;
+			var encoded = WebUtility.HtmlEncode(text);
+			encoded = MentionPattern().Replace(encoded, match =>
+			{
+				if (!mentions.TryGetValue(WebUtility.HtmlDecode(match.Value), out var mention))
+					return match.Value;
+				changed = true;
+				return $"<span class=\"h-card\" translate=\"no\"><a href=\"{WebUtility.HtmlEncode(mention.ProfileUrl)}\" class=\"u-url mention\">@<span>{WebUtility.HtmlEncode(mention.UserName)}</span></a></span>";
+			});
+			encoded = HashtagPattern().Replace(encoded, match =>
+			{
+				var tag = match.Groups["tag"].Value;
+				if (tag.All(char.IsDigit))
+					return match.Value;
+				changed = true;
+				tags.Add(tag.ToLowerInvariant());
+				return $"{match.Groups["lead"].Value}<a href=\"{WebUtility.HtmlEncode(TagUrl(tag.ToLowerInvariant()))}\" class=\"mention hashtag\" rel=\"tag\">#<span>{tag}</span></a>";
+			});
+			return changed ? encoded : default;
+		}
+
+		async Task<ResolvedMention> Resolve(string handle, CancellationToken token)
+		{
+			var parts = handle.TrimStart('@').Split('@');
+			var localDomain = new Uri(_localActors.BaseAddress).Authority;
+			if (parts.Length == 1 || parts[1].Equals(localDomain, StringComparison.OrdinalIgnoreCase))
+			{
+				var local = await _localActors.FindByUserName(parts[0], token);
+				return local is { IsFederated: true, Kind: not LocalActorKind.Application }
+					? new ResolvedMention(local.Uri, local.UserName, local.Domain, local.Uri, true, local.Id, local.Inbox)
+					: default;
+			}
+
+			var actorUri = await _remoteActors.ResolveHandle($"{parts[0]}@{parts[1]}", token);
+			var actor = actorUri == default ? default : await _remoteActors.GetActor(actorUri, refresh: false, token);
+			return actor == default
+				? default
+				: new ResolvedMention(actor.ActorURI, actor.UserName ?? parts[0], parts[1].ToLowerInvariant(), actor.Url ?? actor.ActorURI, false, actor.ID,
+					actor.InboxURL);
+		}
+
+		static string Linkify(string encoded) =>
+			UrlPattern().Replace(encoded, match => $"<a href=\"{match.Value}\">{match.Value}</a>");
+
+		[GeneratedRegex(@"(?<![\w@/.])@[a-zA-Z0-9_]+(?:@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)+(?::\d+)?)?(?![\w@])")]
+		private static partial Regex MentionPattern();
+
+		[GeneratedRegex(@"(?<lead>^|[^\w&#/])#(?<tag>[\p{L}\p{N}_]{1,100})(?![\p{L}\p{N}_])")]
+		private static partial Regex HashtagPattern();
+
+		[GeneratedRegex(@"https?://[^\s<]+[^\s<.,;:!?)\]'""]")]
+		private static partial Regex UrlPattern();
+	}
+}

PrivaPub/Federation/Actors/LocalActorService.cs

@@ -31,18 +31,22 @@ namespace PrivaPub.Federation.Actors
 		public bool IsFederated { get; init; } = true;
 		public DateTime Published { get; init; }
 		public string BaseAddress { get; init; }
+		public IReadOnlyDictionary<string, string> Fields { get; init; } = new Dictionary<string, string>();
 
 		public string Uri => $"{BaseAddress}/peasants/{UserName}";
 		public string KeyId => $"{Uri}#main-key";
 		public string Inbox => $"{Uri}/mouth";
 		public string Outbox => $"{Uri}/anus";
-		public string Followers => $"{Uri}/followers";
-		public string Following => $"{Uri}/following";
+		public string Followers => $"{Uri}/groupies";
+		public string Following => $"{Uri}/stalking";
 		public string SharedInbox => $"{BaseAddress}/human-centipede";
 		public string Domain => new Uri(BaseAddress).Authority;
 		public string Handle => $"{UserName}@{Domain}";
-		public string PostUri(string postId) => $"{Uri}/posts/{postId}";
-		public string ActivityUri(string activityId) => $"{Uri}/activities/{activityId}";
+		public string HtmlUrl => $"{BaseAddress}/@{UserName}";
+		public string PostUri(string postId) => $"{Uri}/scribbles/{postId}";
+		public string PostHtmlUrl(string postId) => $"{HtmlUrl}/{postId}";
+		public string ActivityUri(string activityId) => $"{Uri}/grunts/{activityId}";
+		public string ConversationUri(string conversationId) => $"{Uri}/whispers/{conversationId}";
 	}
 
 	public interface ILocalActorService
@@ -190,6 +194,7 @@ namespace PrivaPub.Federation.Actors
 			PrivateKeyPem = avatar.PrivateKey,
 			PublicKeyPem = avatar.PublicKey,
 			Published = avatar.CreatedAt,
+			Fields = avatar.Fields ?? new Dictionary<string, string>(),
 			BaseAddress = BaseAddress
 		};
 

PrivaPub/Federation/Controllers/PeasantsController.cs

@@ -41,26 +41,39 @@ namespace PrivaPub.Federation.Controllers
 		public async Task<IActionResult> GetActor(string actor, CancellationToken token)
 		{
 			var local = await _localActors.FindByUserName(actor, token);
-			return local is not { IsFederated: true } ? NotFound() : Activity(ActivityPubRenderer.Actor(local));
+			if (local is not { IsFederated: true })
+				return NotFound();
+			if (WantsHtml() && local.Kind != LocalActorKind.Application)
+				return Redirect(local.HtmlUrl);
+			return Activity(ActivityPubRenderer.Actor(local));
 		}
 
 		[HttpGet, Route("{actor}/anus")]
-		public async Task<IActionResult> Outbox(string actor, CancellationToken token)
+		public async Task<IActionResult> Outbox(string actor, [FromQuery] bool page, [FromQuery(Name = "max_id")] string maxId,
+			CancellationToken token)
 		{
 			var local = await _localActors.FindByUserName(actor, token);
 			if (local is not { IsFederated: true })
 				return NotFound();
 
+			if (!page)
+			{
 				var total = local.Kind == LocalActorKind.Group
-				? await DB.Default.CountAsync<PostEntity>(p => p.GroupId == local.Id && (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted), token)
-				: await DB.Default.CountAsync<PostEntity>(p => p.GroupUserId == local.Id && !p.IsFederatedCopy && (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted), token);
+					? await DB.Default.CountAsync<PostEntity>(p => p.GroupId == local.Id && !p.DeletedAt.HasValue
+						&& (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted), token)
+					: await DB.Default.CountAsync<PostEntity>(p => p.GroupUserId == local.Id && !p.IsFederatedCopy && !p.DeletedAt.HasValue
+						&& (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted), token);
+				return Activity(ActivityPubRenderer.OrderedCollection(local.Outbox, (int)total, default, $"{local.Outbox}?page=true"));
+			}
 
-			var latest = await (local.Kind == LocalActorKind.Group
-					? _dbEntities.Posts.Match(p => p.GroupId == local.Id && (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted))
-					: _dbEntities.Posts.Match(p => p.GroupUserId == local.Id && !p.IsFederatedCopy && (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted)))
-				.Sort(p => p.CreationDate, Order.Descending)
-				.Limit(OutboxSize)
-				.ExecuteAsync(token);
+			var query = local.Kind == LocalActorKind.Group
+				? _dbEntities.Posts.Match(p => p.GroupId == local.Id && !p.DeletedAt.HasValue
+					&& (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted))
+				: _dbEntities.Posts.Match(p => p.GroupUserId == local.Id && !p.IsFederatedCopy && !p.DeletedAt.HasValue
+					&& (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted));
+			if (!string.IsNullOrEmpty(maxId))
+				query.Match(f => f.Lt(p => p.ID, maxId));
+			var latest = await query.Sort(p => p.ID, Order.Descending).Limit(OutboxSize).ExecuteAsync(token);
 
 			var items = new List<JsonNode>();
 			foreach (var post in latest)
@@ -70,15 +83,15 @@ namespace PrivaPub.Federation.Controllers
 					items.Add(ActivityPubRenderer.Announce(local, post.ObjectURI, $"announce-{post.ID}"));
 					continue;
 				}
-				var group = string.IsNullOrEmpty(post.GroupId) ? default : await _localActors.FindById(LocalActorKind.Group, post.GroupId, token);
-				var note = ActivityPubRenderer.Note(post, local, group, post.InReplyToURI);
-				items.Add(ActivityPubRenderer.Create(local, note, $"create-{post.ID}"));
+				items.Add(await CreateFor(post, local, token));
 			}
 
-			return Activity(ActivityPubRenderer.OrderedCollection(local.Outbox, (int)total, items));
+			var pageId = string.IsNullOrEmpty(maxId) ? $"{local.Outbox}?page=true" : $"{local.Outbox}?page=true&max_id={maxId}";
+			var next = latest.Count == OutboxSize ? $"{local.Outbox}?page=true&max_id={latest[^1].ID}" : default;
+			return Activity(ActivityPubRenderer.OrderedCollectionPage(pageId, local.Outbox, items, next, default));
 		}
 
-		[HttpGet, Route("{actor}/followers")]
+		[HttpGet, Route("{actor}/groupies")]
 		public async Task<IActionResult> Followers(string actor, CancellationToken token)
 		{
 			var local = await _localActors.FindByUserName(actor, token);
@@ -89,32 +102,37 @@ namespace PrivaPub.Federation.Controllers
 			return Activity(ActivityPubRenderer.OrderedCollection(local.Followers, (int)count, default));
 		}
 
-		[HttpGet, Route("{actor}/following")]
+		[HttpGet, Route("{actor}/stalking")]
 		public async Task<IActionResult> Following(string actor, CancellationToken token)
 		{
 			var local = await _localActors.FindByUserName(actor, token);
-			return local is not { IsFederated: true } ? NotFound() : Activity(ActivityPubRenderer.OrderedCollection(local.Following, 0, Enumerable.Empty<JsonNode>()));
+			return local is not { IsFederated: true } ? NotFound() : Activity(ActivityPubRenderer.OrderedCollection(local.Following, 0, default));
 		}
 
-		[HttpGet, Route("{actor}/posts/{postId}")]
+		[HttpGet, Route("{actor}/scribbles/{postId}")]
 		public async Task<IActionResult> Post(string actor, string postId, CancellationToken token)
 		{
-			var local = await _localActors.FindByUserName(actor, token);
-			if (local == default || local.Kind != LocalActorKind.Person)
-				return NotFound();
-
-			var post = await _dbEntities.Posts
-				.Match(p => p.ID == postId && p.GroupUserId == local.Id && !p.IsFederatedCopy && (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted))
-				.ExecuteFirstAsync(token);
+			var (local, post) = await PublicPost(actor, postId, token);
 			if (post == default)
 				return NotFound();
+			if (WantsHtml())
+				return Redirect(local.PostHtmlUrl(post.ID));
 
 			var group = string.IsNullOrEmpty(post.GroupId) ? default : await _localActors.FindById(LocalActorKind.Group, post.GroupId, token);
 			var note = ActivityPubRenderer.Note(post, local, group, post.InReplyToURI);
-			note["@context"] = ActivityPubRenderer.ActivityStreams;
+			note["@context"] = ActivityPubRenderer.Context();
 			return Activity(note);
 		}
 
+		[HttpGet, Route("{actor}/grunts/{activityId}")]
+		public async Task<IActionResult> Grunt(string actor, string activityId, CancellationToken token)
+		{
+			if (!activityId.StartsWith("create-", StringComparison.Ordinal))
+				return NotFound();
+			var (local, post) = await PublicPost(actor, activityId["create-".Length..], token);
+			return post == default ? NotFound() : Activity(await CreateFor(post, local, token));
+		}
+
 		[HttpPost, Route("{actor}/mouth"), EnableRateLimiting(RateLimiting.Inbox)]
 		public async Task<IActionResult> Inbox(string actor, CancellationToken token)
 		{
@@ -132,6 +150,33 @@ namespace PrivaPub.Federation.Controllers
 		public async Task<IActionResult> SharedInbox(CancellationToken token) =>
 			Answer(await _inbox.Receive(Request, default, token));
 
+		async Task<(LocalActor Actor, PostEntity Post)> PublicPost(string actor, string postId, CancellationToken token)
+		{
+			var local = await _localActors.FindByUserName(actor, token);
+			if (local is not { IsFederated: true, Kind: LocalActorKind.Person })
+				return default;
+			var post = await _dbEntities.Posts
+				.Match(p => p.ID == postId && p.GroupUserId == local.Id && !p.IsFederatedCopy && !p.DeletedAt.HasValue
+					&& (p.Visibility == PostVisibility.Public || p.Visibility == PostVisibility.Unlisted))
+				.ExecuteFirstAsync(token);
+			return (local, post);
+		}
+
+		async Task<JsonObject> CreateFor(PostEntity post, LocalActor author, CancellationToken token)
+		{
+			var group = string.IsNullOrEmpty(post.GroupId) ? default : await _localActors.FindById(LocalActorKind.Group, post.GroupId, token);
+			var note = ActivityPubRenderer.Note(post, author, group, post.InReplyToURI);
+			return ActivityPubRenderer.Create(author, note, $"create-{post.ID}");
+		}
+
+		bool WantsHtml()
+		{
+			var accept = Request.Headers.Accept.ToString();
+			return accept.Contains("text/html", StringComparison.OrdinalIgnoreCase)
+				&& !accept.Contains("activity+json", StringComparison.OrdinalIgnoreCase)
+				&& !accept.Contains("ld+json", StringComparison.OrdinalIgnoreCase);
+		}
+
 		IActionResult Answer(InboxResult result)
 		{
 			if (result.Error != default)

PrivaPub/Federation/Controllers/WellKnownController.cs

@@ -49,10 +49,12 @@ namespace PrivaPub.Federation.Controllers
 			var document = new JsonObject
 			{
 				["subject"] = $"acct:{actor.Handle}",
-				["aliases"] = new JsonArray(actor.Uri),
-				["links"] = new JsonArray(
-					new JsonObject { ["rel"] = "self", ["type"] = "application/activity+json", ["href"] = actor.Uri },
-					new JsonObject { ["rel"] = "http://webfinger.net/rel/profile-page", ["type"] = "text/html", ["href"] = actor.Uri })
+				["aliases"] = actor.Kind == LocalActorKind.Application ? new JsonArray(actor.Uri) : new JsonArray(actor.HtmlUrl, actor.Uri),
+				["links"] = actor.Kind == LocalActorKind.Application
+					? new JsonArray(new JsonObject { ["rel"] = "self", ["type"] = "application/activity+json", ["href"] = actor.Uri })
+					: new JsonArray(
+						new JsonObject { ["rel"] = "http://webfinger.net/rel/profile-page", ["type"] = "text/html", ["href"] = actor.HtmlUrl },
+						new JsonObject { ["rel"] = "self", ["type"] = "application/activity+json", ["href"] = actor.Uri })
 			};
 			return Content(document.ToJsonString(), "application/jrd+json; charset=utf-8");
 		}

PrivaPub/Federation/Rendering/ActivityPubRenderer.cs

@@ -1,33 +1,65 @@
 using Markdig;
 
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Objects;
 using PrivaPub.Models.Federation;
+using PrivaPub.Models.Post;
 
 using System.Globalization;
+using System.Net;
 using System.Text.Json.Nodes;
 
 using PostEntity = PrivaPub.Models.Post.Post;
-using PrivaPub.Federation.Actors;
 
 namespace PrivaPub.Federation.Rendering
 {
 	public static class ActivityPubRenderer
 	{
 		public const string ActivityStreams = "https://www.w3.org/ns/activitystreams";
-		public const string Public = "https://www.w3.org/ns/activitystreams#Public";
+		public const string Public = Addressing.Public;
+		public const string ContentWarning = "Content warning";
 
 		static readonly MarkdownPipeline Pipeline = new MarkdownPipelineBuilder().DisableHtml().Build();
 
+		public static JsonArray Context() => new(
+			ActivityStreams,
+			"https://w3id.org/security/v1",
+			new JsonObject
+			{
+				["manuallyApprovesFollowers"] = "as:manuallyApprovesFollowers",
+				["sensitive"] = "as:sensitive",
+				["Hashtag"] = "as:Hashtag",
+				["alsoKnownAs"] = new JsonObject { ["@id"] = "as:alsoKnownAs", ["@type"] = "@id" },
+				["movedTo"] = new JsonObject { ["@id"] = "as:movedTo", ["@type"] = "@id" },
+				["toot"] = "http://joinmastodon.org/ns#",
+				["featured"] = new JsonObject { ["@id"] = "toot:featured", ["@type"] = "@id" },
+				["featuredTags"] = new JsonObject { ["@id"] = "toot:featuredTags", ["@type"] = "@id" },
+				["discoverable"] = "toot:discoverable",
+				["indexable"] = "toot:indexable",
+				["blurhash"] = "toot:blurhash",
+				["focalPoint"] = new JsonObject { ["@container"] = "@list", ["@id"] = "toot:focalPoint" },
+				["schema"] = "http://schema.org#",
+				["PropertyValue"] = "schema:PropertyValue",
+				["value"] = "schema:value",
+				["webfinger"] = "https://purl.archive.org/socialweb/webfinger#webfinger"
+			});
+
 		public static string Html(string markdown) =>
 			string.IsNullOrEmpty(markdown) ? string.Empty : Markdown.ToHtml(markdown, Pipeline).Trim();
 
 		public static string Timestamp(DateTime value) =>
 			DateTime.SpecifyKind(value, DateTimeKind.Utc).ToString("yyyy-MM-ddTHH:mm:ssZ", CultureInfo.InvariantCulture);
 
+		public static string Day(DateTime value) =>
+			DateTime.SpecifyKind(value, DateTimeKind.Utc).Date.ToString("yyyy-MM-ddT00:00:00Z", CultureInfo.InvariantCulture);
+
+		public static string TagUrl(string baseAddress, string tag) => $"{baseAddress}/tags/{Uri.EscapeDataString(tag)}";
+
 		public static JsonObject Actor(LocalActor actor)
 		{
 			var document = new JsonObject
 			{
-				["@context"] = new JsonArray(ActivityStreams, "https://w3id.org/security/v1"),
+				["@context"] = Context(),
 				["id"] = actor.Uri,
 				["type"] = actor.Kind switch
 				{
@@ -38,21 +70,29 @@ namespace PrivaPub.Federation.Rendering
 				["preferredUsername"] = actor.UserName,
 				["name"] = actor.Name,
 				["summary"] = Html(actor.Summary),
-				["url"] = actor.Uri,
+				["url"] = actor.Kind == LocalActorKind.Application ? actor.Uri : actor.HtmlUrl,
 				["inbox"] = actor.Inbox,
 				["outbox"] = actor.Outbox,
 				["followers"] = actor.Followers,
 				["following"] = actor.Following,
-				["published"] = Timestamp(actor.Published),
+				["published"] = Day(actor.Published),
 				["manuallyApprovesFollowers"] = actor.ManuallyApprovesFollowers,
 				["discoverable"] = actor.Discoverable,
+				["indexable"] = false,
+				["webfinger"] = actor.Handle,
 				["endpoints"] = new JsonObject { ["sharedInbox"] = actor.SharedInbox },
 				["publicKey"] = new JsonObject
 				{
 					["id"] = actor.KeyId,
 					["owner"] = actor.Uri,
 					["publicKeyPem"] = Keys.ToSubjectPublicKeyInfoPem(actor.PublicKeyPem)
-				}
+				},
+				["attachment"] = new JsonArray(actor.Fields.Select(field => (JsonNode)new JsonObject
+				{
+					["type"] = "PropertyValue",
+					["name"] = field.Key,
+					["value"] = FieldValue(field.Value)
+				}).ToArray())
 			};
 			if (!string.IsNullOrEmpty(actor.PictureURL))
 				document["icon"] = new JsonObject { ["type"] = "Image", ["url"] = actor.PictureURL };
@@ -63,13 +103,18 @@ namespace PrivaPub.Federation.Rendering
 
 		public static JsonObject Note(PostEntity post, LocalActor author, LocalActor group, string inReplyTo)
 		{
-			var to = new JsonArray(Public);
-			var cc = new JsonArray(author.Followers);
+			var mentions = post.Mentions.Select(m => (JsonNode)m.ActorURI).ToArray();
+			var (to, cc) = post.Visibility switch
+			{
+				PostVisibility.Unlisted => (new JsonArray(author.Followers), new JsonArray(mentions.Prepend(Public).ToArray())),
+				PostVisibility.FollowersOnly => (new JsonArray(author.Followers), new JsonArray(mentions)),
+				PostVisibility.Direct => (new JsonArray(mentions), new JsonArray()),
+				_ => (new JsonArray(Public), new JsonArray(mentions.Prepend(author.Followers).ToArray()))
+			};
 			if (group != default)
 				cc.Add(group.Uri);
 
-			var note = NoteBody(author.PostUri(post.ID), author, post.Title, post.Text, post.HasContentWarning,
-				post.CreationDate, to, cc, inReplyTo);
+			var note = NoteBody(post, author, to, cc, inReplyTo);
 			if (group != default)
 				note["audience"] = group.Uri;
 			return note;
@@ -78,48 +123,84 @@ namespace PrivaPub.Federation.Rendering
 		public static JsonObject DirectNote(PostEntity post, LocalActor author, IReadOnlyList<(string Uri, string Handle)> recipients,
 			string context)
 		{
-			var note = NoteBody(author.PostUri(post.ID), author, post.Title, post.Text, post.HasContentWarning,
-				post.CreationDate, new JsonArray(recipients.Select(r => (JsonNode)r.Uri).ToArray()), new JsonArray(), default);
-			note["tag"] = new JsonArray(recipients.Select(r => (JsonNode)new JsonObject
-			{
-				["type"] = "Mention",
-				["href"] = r.Uri,
-				["name"] = "@" + r.Handle
-			}).ToArray());
-			note["content"] = string.Join(" ", recipients.Select(r => $"<span class=\"h-card\"><a href=\"{r.Uri}\" class=\"u-url mention\">@{r.Handle}</a></span>"))
-				+ " " + note["content"]!.GetValue<string>();
+			var note = NoteBody(post, author, new JsonArray(recipients.Select(r => (JsonNode)r.Uri).ToArray()), new JsonArray(), post.InReplyToURI);
+			var named = post.Mentions.Select(m => m.ActorURI).ToHashSet();
+			var tags = note["tag"]!.AsArray();
+			foreach (var recipient in recipients.Where(r => !named.Contains(r.Uri)))
+				tags.Add(new JsonObject { ["type"] = "Mention", ["href"] = recipient.Uri, ["name"] = "@" + recipient.Handle });
+			var unmentioned = recipients.Where(r => !named.Contains(r.Uri)).ToList();
+			if (unmentioned.Count > 0)
+				note["content"] = "<p>" + string.Join(" ", unmentioned.Select(r =>
+						$"<span class=\"h-card\" translate=\"no\"><a href=\"{WebUtility.HtmlEncode(r.Uri)}\" class=\"u-url mention\">@<span>{WebUtility.HtmlEncode(r.Handle.Split('@')[0])}</span></a></span>"))
+					+ "</p>" + note["content"]!.GetValue<string>();
 			if (!string.IsNullOrEmpty(context))
 				note["context"] = context;
 			return note;
 		}
 
-		static JsonObject NoteBody(string id, LocalActor author, string title, string text, bool sensitive,
-			DateTime published, JsonArray to, JsonArray cc, string inReplyTo)
+		static JsonObject NoteBody(PostEntity post, LocalActor author, JsonArray to, JsonArray cc, string inReplyTo)
 		{
+			var content = post.ContentHtml ?? Html(post.Text);
+			if (!string.IsNullOrEmpty(post.Title))
+				content = $"<p><strong>{WebUtility.HtmlEncode(post.Title)}</strong></p>{content}";
+
 			var note = new JsonObject
 			{
-				["id"] = id,
+				["id"] = author.PostUri(post.ID),
 				["type"] = "Note",
 				["attributedTo"] = author.Uri,
-				["content"] = Html(text),
-				["published"] = Timestamp(published),
-				["url"] = id,
+				["content"] = content,
+				["published"] = Timestamp(post.CreationDate),
+				["url"] = author.PostHtmlUrl(post.ID),
 				["to"] = to,
 				["cc"] = cc,
-				["sensitive"] = sensitive
+				["sensitive"] = post.HasContentWarning,
+				["tag"] = new JsonArray(post.Mentions
+					.Select(m => (JsonNode)new JsonObject { ["type"] = "Mention", ["href"] = m.ActorURI, ["name"] = MentionName(m) })
+					.Concat(post.Tags.Select(t => (JsonNode)new JsonObject
+					{
+						["type"] = "Hashtag",
+						["href"] = TagUrl(author.BaseAddress, t),
+						["name"] = "#" + t
+					}))
+					.ToArray())
 			};
-			if (sensitive && !string.IsNullOrEmpty(title))
-				note["summary"] = title;
-			else if (!string.IsNullOrEmpty(title))
-				note["name"] = title;
+			if (!string.IsNullOrEmpty(post.Language))
+				note["contentMap"] = new JsonObject { [post.Language] = content };
+			if (!string.IsNullOrEmpty(post.Title))
+				note["name"] = post.Title;
+			var summary = post.SpoilerText ?? (post.HasContentWarning ? post.Title ?? ContentWarning : default);
+			if (!string.IsNullOrEmpty(summary))
+			{
+				note["summary"] = summary;
+				note["sensitive"] = true;
+			}
 			if (!string.IsNullOrEmpty(inReplyTo))
 				note["inReplyTo"] = inReplyTo;
+			if (post.EditedAt.HasValue)
+				note["updated"] = Timestamp(post.EditedAt.Value);
 			return note;
 		}
 
+		static string MentionName(PostMention mention)
+		{
+			var handle = mention.Handle?.TrimStart('@');
+			if (string.IsNullOrEmpty(handle))
+				return "@" + mention.ActorURI;
+			return "@" + (handle.Contains('@') ? handle : $"{handle}@{new Uri(mention.ActorURI).Authority}");
+		}
+
+		static string FieldValue(string value)
+		{
+			var encoded = WebUtility.HtmlEncode(value ?? string.Empty);
+			return Uri.TryCreate(value, UriKind.Absolute, out var link) && link.Scheme is "https" or "http"
+				? $"<a href=\"{encoded}\" target=\"_blank\" rel=\"nofollow noopener noreferrer me\" translate=\"no\">{encoded}</a>"
+				: encoded;
+		}
+
 		public static JsonObject Create(LocalActor actor, JsonObject note, string activityId) => new()
 		{
-			["@context"] = ActivityStreams,
+			["@context"] = Context(),
 			["id"] = actor.ActivityUri(activityId),
 			["type"] = "Create",
 			["actor"] = actor.Uri,
@@ -161,7 +242,7 @@ namespace PrivaPub.Federation.Rendering
 			["object"] = follow.DeepClone()
 		};
 
-		public static JsonObject OrderedCollection(string id, int totalItems, IEnumerable<JsonNode> items)
+		public static JsonObject OrderedCollection(string id, int totalItems, IEnumerable<JsonNode> items, string first = default)
 		{
 			var collection = new JsonObject
 			{
@@ -170,9 +251,28 @@ namespace PrivaPub.Federation.Rendering
 				["type"] = "OrderedCollection",
 				["totalItems"] = totalItems
 			};
+			if (first != default)
+				collection["first"] = first;
 			if (items != default)
 				collection["orderedItems"] = new JsonArray(items.ToArray());
 			return collection;
 		}
+
+		public static JsonObject OrderedCollectionPage(string id, string partOf, IEnumerable<JsonNode> items, string next, string prev)
+		{
+			var page = new JsonObject
+			{
+				["@context"] = Context(),
+				["id"] = id,
+				["type"] = "OrderedCollectionPage",
+				["partOf"] = partOf,
+				["orderedItems"] = new JsonArray(items.ToArray())
+			};
+			if (next != default)
+				page["next"] = next;
+			if (prev != default)
+				page["prev"] = prev;
+			return page;
+		}
 	}
 }

PrivaPub/Middleware/SocialPubConfigurations.cs

@@ -15,6 +15,7 @@ using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Outbox;
 using PrivaPub.Federation.Inbox;
 using PrivaPub.Federation.Inbox.Handlers;
+using PrivaPub.Domain.Content;
 using PrivaPub.Infrastructure.Http;
 using PrivaPub.Infrastructure.Jobs;
 using Microsoft.Extensions.Options;
@@ -49,6 +50,7 @@ namespace PrivaPub.Middleware
 					SafeHttpHandlerFactory.Create(provider.GetRequiredService<IOptions<FederationOptions>>().Value));
 			return service
 				.AddSingleton<IFederationHttp, FederationHttp>()
+				.AddSingleton<IContentRenderer, ContentRenderer>()
 				.AddSingleton<ILocalActorService, LocalActorService>()
 				.AddSingleton<IRemoteActorService, RemoteActorService>()
 				.AddSingleton<IDeliveryService, DeliveryService>()

PrivaPub/Services/PostsService.cs

@@ -13,6 +13,7 @@ using PrivaPub.StaticServices;
 using System.Text.Json.Nodes;
 
 using PostEntity = PrivaPub.Models.Post.Post;
+using PrivaPub.Domain.Content;
 using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Rendering;
 using PrivaPub.Federation.Outbox;
@@ -36,6 +37,7 @@ namespace PrivaPub.Services
 		readonly ILocalActorService _localActors;
 		readonly IRemoteActorService _remoteActors;
 		readonly IDeliveryService _delivery;
+		readonly IContentRenderer _content;
 		readonly IStringLocalizer<GenericRes> _localizer;
 		readonly ILogger<PostsService> _logger;
 
@@ -43,6 +45,7 @@ namespace PrivaPub.Services
 			ILocalActorService localActors,
 			IRemoteActorService remoteActors,
 			IDeliveryService delivery,
+			IContentRenderer content,
 			IStringLocalizer<GenericRes> localizer,
 			ILogger<PostsService> logger)
 		{
@@ -50,6 +53,7 @@ namespace PrivaPub.Services
 			_localActors = localActors;
 			_remoteActors = remoteActors;
 			_delivery = delivery;
+			_content = content;
 			_localizer = localizer;
 			_logger = logger;
 		}
@@ -76,6 +80,7 @@ namespace PrivaPub.Services
 				}
 
 				var parent = await Parent(form.AnsweringToPostId, token);
+				var rendered = await _content.Markdown(form.Text, token);
 				var post = new PostEntity
 				{
 					GroupUserId = author.Id,
@@ -84,8 +89,10 @@ namespace PrivaPub.Services
 					Visibility = isLocalOnly ? PostVisibility.Circle : PostVisibility.Public,
 					Title = form.Title,
 					Text = form.Text,
-					ContentHtml = ActivityPubRenderer.Html(form.Text),
+					ContentHtml = rendered.Html,
 					ContentFormat = ContentFormat.Markdown,
+					Mentions = rendered.Mentions.Select(ToMention).ToList(),
+					Tags = rendered.Tags.ToList(),
 					HasContentWarning = form.HasContentWarning,
 					AnsweringToPostId = parent?.ID,
 					InReplyToURI = parent?.ObjectURI ?? RemoteUri(form.AnsweringToPostId),
@@ -95,7 +102,7 @@ namespace PrivaPub.Services
 				};
 				post.ID = (string)post.GenerateNewID();
 				post.ObjectURI = author.PostUri(post.ID);
-				post.Url = post.ObjectURI;
+				post.Url = author.PostHtmlUrl(post.ID);
 
 				if (isLocalOnly)
 				{
@@ -113,7 +120,10 @@ namespace PrivaPub.Services
 				if (parent != default)
 					await DB.Default.Update<PostEntity>().MatchID(parent.ID).Modify(b => b.Inc(p => p.RepliesCount, 1)).ExecuteAsync(token);
 
-				await _delivery.EnqueueToFollowers(author, create, token);
+				var addressedInboxes = rendered.Mentions.Where(m => !m.IsLocal).Select(m => m.Inbox).ToList();
+				if (parent is { IsFederatedCopy: true } && !string.IsNullOrEmpty(parent.AuthorAccountId))
+					addressedInboxes.Add((await _dbEntities.ForeignAvatars.MatchID(parent.AuthorAccountId).ExecuteFirstAsync(token))?.InboxURL);
+				await _delivery.EnqueueToFollowers(author, create, token, addressedInboxes);
 				if (group != default)
 					await _delivery.EnqueueToFollowers(group, ActivityPubRenderer.Announce(group, post.ObjectURI, $"announce-{post.ID}"), token);
 
@@ -248,7 +258,7 @@ namespace PrivaPub.Services
 					{
 						dmGroup = new DmGroup { Members = members, ParticipantsKey = key };
 						dmGroup.ID = (string)dmGroup.GenerateNewID();
-						dmGroup.ConversationURI = $"{author.Uri}/conversations/{dmGroup.ID}";
+						dmGroup.ConversationURI = author.ConversationUri(dmGroup.ID);
 						await DB.Default.SaveAsync(dmGroup, token);
 					}
 				}
@@ -261,14 +271,14 @@ namespace PrivaPub.Services
 					Visibility = PostVisibility.Direct,
 					ContextURI = dmGroup.ConversationURI,
 					Text = form.Text,
-					ContentHtml = ActivityPubRenderer.Html(form.Text),
+					ContentHtml = (await _content.Markdown(form.Text, token)).Html,
 					ContentFormat = ContentFormat.Markdown,
 					HasContentWarning = form.HasContentWarning,
 					ActorURI = author.Uri
 				};
 				dm.ID = (string)dm.GenerateNewID();
 				dm.ObjectURI = author.PostUri(dm.ID);
-				dm.Url = dm.ObjectURI;
+				dm.Url = author.PostHtmlUrl(dm.ID);
 
 				var remote = new List<(string Uri, string Handle)>();
 				var inboxes = new List<string>();
@@ -377,6 +387,14 @@ namespace PrivaPub.Services
 				: await _dbEntities.Posts.MatchID(answeringTo).ExecuteFirstAsync(token);
 		}
 
+		static PostMention ToMention(ResolvedMention mention) => new()
+		{
+			ActorURI = mention.ActorUri,
+			Handle = "@" + mention.Handle,
+			IsLocal = mention.IsLocal,
+			AccountId = mention.AccountId
+		};
+
 		static string RemoteUri(string answeringTo) =>
 			answeringTo != default && answeringTo.StartsWith("https://", StringComparison.OrdinalIgnoreCase) ? answeringTo : default;