P6 done: personas can be quoted, under the owner's default of anyone, automatically

- Our public and unlisted posts state interactionPolicy.canQuote. The policy comes from the post, then the persona
  (`source[quote_policy]`: public, followers or nobody; default public as the owner chose), and is always nobody for
  followers-only posts and DMs.
- QuoteRequests are answered with Accept{result} naming a parrot-licence at /peasants/{name}/parrot-licences/{id}
  (the route name the owner chose), or with Reject. Followers-only checks that the requester really follows.
- A licence is a QuoteAuthorization naming both posts; revoking it (POST /api/v1/statuses/:id/quotes/:quoting_id/revoke)
  marks it 410, sends Delete{licence} to the quoter and the persona's followers, and revokes our own copy of the quote.
- A quote that arrives with one of our licences is accepted only if that licence is ours, unrevoked and names exactly
  that quoting post. One persona quoting another gets a licence too.
- Mastodon API: quote_approval for our posts (automatic, followers, current_user), `quote_approval_policy` when posting,
  PUT /api/v1/statuses/:id/interaction_policy, `source.quote_policy`.

Checked live: GoToSocial still accepts our posts with the policy stated, and leaves likes, replies and boosts open.

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

PrivaPub/Api/Mastodon/Controllers/AccountsController.cs

@@ -79,6 +79,8 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				avatar.Settings.DefaultSensitive = sensitive;
 			if (Params.Has("source[language]"))
 				avatar.Settings.DefaultLanguage = Params.Get("source[language]");
+			if (Params.Get("source[quote_policy]") is { } quotePolicy && QuotePolicies.IsKnown(quotePolicy))
+				avatar.Settings.QuotePolicy = quotePolicy;
 			var fields = new Dictionary<string, string>();
 			for (var i = 0; i < 4; i++)
 			{

PrivaPub/Api/Mastodon/Controllers/StatusesController.cs

@@ -9,6 +9,9 @@ using PrivaPub.Api.Mastodon.Mappers;
 using PrivaPub.Domain.Privacy;
 using PrivaPub.Domain.Statuses;
 using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
+using PrivaPub.Federation.Rendering;
+using PrivaPub.Federation.Outbox;
 using PrivaPub.StaticServices;
 
 using PostEntity = PrivaPub.Models.Post.Post;
@@ -24,9 +27,14 @@ namespace PrivaPub.Api.Mastodon.Controllers
 		readonly MastodonMapper _mapper;
 		readonly DbEntities _dbEntities;
 		readonly IMemoryCache _cache;
+		readonly IQuoteService _quotes;
+		readonly IOutboxPublisher _outbox;
 
-		public StatusesController(IStatusService statuses, MastodonMapper mapper, DbEntities dbEntities, IMemoryCache cache)
+		public StatusesController(IStatusService statuses, MastodonMapper mapper, DbEntities dbEntities, IMemoryCache cache, IQuoteService quotes,
+			IOutboxPublisher outbox)
 		{
+			_quotes = quotes;
+			_outbox = outbox;
 			_statuses = statuses;
 			_mapper = mapper;
 			_dbEntities = dbEntities;
@@ -55,6 +63,7 @@ namespace PrivaPub.Api.Mastodon.Controllers
 				Language = Params.Get("language") ?? Me.Settings.DefaultLanguage,
 				MediaIds = Params.List("media_ids"),
 				QuotedStatusId = Params.Get("quoted_status_id"),
+				QuotePolicy = Params.Get("quote_approval_policy"),
 				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)
@@ -242,6 +251,32 @@ namespace PrivaPub.Api.Mastodon.Controllers
 			return Json(await _mapper.Statuses(visible, MyId, token));
 		}
 
+		[HttpPost("/api/v1/statuses/{id}/quotes/{quotingId}/revoke"), Scope("write:statuses")]
+		public async Task<IActionResult> RevokeQuote(string id, string quotingId, CancellationToken token)
+		{
+			var quoted = await _dbEntities.Posts.Match(p => p.ID == id && p.GroupUserId == MyId && !p.IsFederatedCopy && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			var quoting = quoted == default ? default : await _dbEntities.Posts.Match(p => p.ID == quotingId && p.QuotedPostId == quoted.ID).ExecuteFirstAsync(token);
+			if (quoting == default || !await _quotes.RevokeLicence(quoted, quoting, token))
+				return NotFoundError();
+			return Json(await _mapper.Status(await _dbEntities.Posts.MatchID(quoting.ID).ExecuteFirstAsync(token), MyId, token));
+		}
+
+		[HttpPut("/api/v1/statuses/{id}/interaction_policy"), Scope("write:statuses")]
+		public async Task<IActionResult> InteractionPolicy(string id, CancellationToken token)
+		{
+			var post = await _dbEntities.Posts.Match(p => p.ID == id && p.GroupUserId == MyId && !p.IsFederatedCopy && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			if (post == default)
+				return NotFoundError();
+			var policy = Params.Get("quote_approval_policy");
+			if (!QuotePolicies.IsKnown(policy))
+				return Error(StatusCodes.Status422UnprocessableEntity, "Validation failed: Unknown quote approval policy");
+			await DB.Default.Update<PostEntity>().MatchID(post.ID).Modify(p => p.LocalQuotePolicy, policy).ExecuteAsync(token);
+			post.LocalQuotePolicy = policy;
+			if (!post.IsLocalOnly)
+				await _outbox.Publish(Me, post, ActivityPubRenderer.UpdateOf(post, Me, $"policy-{DateTime.UtcNow.Ticks}"), token);
+			return Json(await _mapper.Status(post, MyId, token));
+		}
+
 		[HttpPost("/api/v1/statuses/{id}/bookmark"), Scope("write:bookmarks")]
 		public async Task<IActionResult> Bookmark(string id, CancellationToken token)
 		{

PrivaPub/Api/Mastodon/Entities/Entities.cs

@@ -59,6 +59,7 @@ namespace PrivaPub.Api.Mastodon.Entities
 		public List<Field> Fields { get; set; } = new();
 		public int FollowRequestsCount { get; set; }
 		public string AttributionDomains { get; set; }
+		public string QuotePolicy { get; set; } = "public";
 	}
 
 	public class PrivaPubStatus

PrivaPub/Api/Mastodon/Mappers/MastodonMapper.cs

@@ -93,6 +93,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 					Privacy = actor.Settings.DefaultVisibility ?? "public",
 					Sensitive = actor.Settings.DefaultSensitive,
 					Language = actor.Settings.DefaultLanguage,
+					QuotePolicy = actor.Settings.QuotePolicy ?? QuotePolicies.Public,
 					Note = actor.Summary ?? string.Empty,
 					Fields = actor.Fields.Select(f => new Field { Name = f.Key, Value = f.Value }).ToList(),
 					FollowRequestsCount = (int)await DB.Default.CountAsync<Follower>(f => f.LocalActorId == actor.Id && !f.IsAccepted, token)
@@ -238,6 +239,10 @@ namespace PrivaPub.Api.Mastodon.Mappers
 				return status;
 			}
 
+			var localAuthors = all.Where(p => !p.IsFederatedCopy && p.GroupUserId != default).Select(p => p.GroupUserId).Distinct().ToList();
+			var followsAuthor = viewerId == default || localAuthors.Count == 0
+				? new HashSet<string>()
+				: await FollowedLocalAuthors(viewerId, localAuthors, token);
 			var quotedIds = nested ? new List<string>() : all.Where(p => p.QuoteState == QuoteState.Accepted && p.QuotedPostId != default).Select(p => p.QuotedPostId).Distinct().ToList();
 			var quotedPosts = new List<PostEntity>();
 			foreach (var quotedPost in quotedIds.Count == 0 ? new List<PostEntity>() : await _dbEntities.Posts.Match(p => quotedIds.Contains(p.ID) && !p.DeletedAt.HasValue).ExecuteAsync(token))
@@ -250,7 +255,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			void Quote(Status status, PostEntity post)
 			{
 				status.QuotesCount = post.QuotesCount;
-				status.QuoteApproval = Approval(post, viewerId);
+				status.QuoteApproval = post.IsFederatedCopy ? Approval(post, viewerId) : LocalApproval(post, viewerId, followsAuthor.Contains(post.GroupUserId));
 				if (post.QuoteState == QuoteState.None)
 					return;
 				var state = post.QuoteState.ToString().ToLowerInvariant();
@@ -300,6 +305,27 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			return document.Body!.InnerHtml;
 		}
 
+		async Task<HashSet<string>> FollowedLocalAuthors(string viewerId, List<string> authorIds, CancellationToken token)
+		{
+			var uris = new Dictionary<string, string>();
+			foreach (var avatar in await _dbEntities.Avatars.Match(a => authorIds.Contains(a.ID)).ExecuteAsync(token))
+				uris[_localActors.FromAvatar(avatar).Uri] = avatar.ID;
+			var targets = uris.Keys.ToList();
+			return (await _dbEntities.Followings.Match(f => f.AvatarId == viewerId && targets.Contains(f.TargetActorURI) && f.State == FollowState.Accepted).ExecuteAsync(token))
+				.Select(f => uris[f.TargetActorURI]).ToHashSet();
+		}
+
+		static QuoteApprovalEntity LocalApproval(PostEntity post, string viewerId, bool viewerFollows)
+		{
+			var policy = ActivityPubRenderer.QuotableBy(post);
+			var everyone = policy switch { QuotePolicies.Public => new List<string> { "public" }, QuotePolicies.Followers => new List<string> { "followers" }, _ => new List<string>() };
+			var current = viewerId == default ? "unknown"
+				: viewerId == post.GroupUserId && post.Visibility is PostVisibility.Public or PostVisibility.Unlisted ? "automatic"
+				: policy == QuotePolicies.Public || policy == QuotePolicies.Followers && viewerFollows ? "automatic"
+				: "denied";
+			return new QuoteApprovalEntity { Automatic = everyone, CurrentUser = current };
+		}
+
 		static QuoteApprovalEntity Approval(PostEntity post, string viewerId)
 		{
 			if (!post.IsFederatedCopy || post.Visibility is not (PostVisibility.Public or PostVisibility.Unlisted))

PrivaPub/Domain/Statuses/QuoteService.cs

@@ -25,7 +25,10 @@ namespace PrivaPub.Domain.Statuses
 		Task Resolve(PostEntity post, NoteDocument note, CancellationToken token);
 		Task Revoke(string stampUri, CancellationToken token);
 		Task<bool> Verified(string stampUri, string quotingUri, PostEntity quoted, CancellationToken token);
-		QuotePermission Permission(PostEntity quoted, LocalActor author);
+		Task<QuotePermission> Permission(PostEntity quoted, LocalActor author, CancellationToken token);
+		Task<string> Grant(LocalActor author, PostEntity quoted, string quotingUri, string quoterUri, CancellationToken token);
+		Task ReceiveRequest(JsonNode request, ForeignAvatar actor, CancellationToken token);
+		Task<bool> RevokeLicence(PostEntity quoted, PostEntity quoting, CancellationToken token);
 		Task Request(LocalActor author, PostEntity post, PostEntity quoted, JsonObject note, CancellationToken token);
 		Task<bool> Answered(JsonNode answer, ForeignAvatar actor, bool accepted, CancellationToken token);
 	}
@@ -59,12 +62,115 @@ namespace PrivaPub.Domain.Statuses
 
 		const string RequestPrefix = "quote-request-";
 
-		public QuotePermission Permission(PostEntity quoted, LocalActor author)
+		const string LicencePath = "/parrot-licences/";
+
+		public static string LicenceUri(LocalActor author, string licenceId) => author.Uri + LicencePath + licenceId;
+
+		async Task<bool> MayQuote(PostEntity quoted, string quoterUri, CancellationToken token)
+		{
+			var author = await _localActors.FindById(LocalActorKind.Person, quoted.GroupUserId, token);
+			if (author == default)
+				return false;
+			if (quoterUri == author.Uri)
+				return quoted.Visibility is PostVisibility.Public or PostVisibility.Unlisted;
+			return ActivityPubRenderer.QuotableBy(quoted) switch
+			{
+				QuotePolicies.Public => true,
+				QuotePolicies.Followers => await Follows(quoterUri, author, token),
+				_ => false
+			};
+		}
+
+		async Task<bool> Follows(string followerUri, LocalActor author, CancellationToken token)
+		{
+			if (await _dbEntities.Followers.Match(f => f.LocalActorId == author.Id && f.ActorURI == followerUri && f.IsAccepted).ExecuteAnyAsync(token))
+				return true;
+			var local = await _localActors.FindByUri(followerUri, token);
+			return local != default
+				&& await _dbEntities.Followings.Match(f => f.AvatarId == local.Id && f.TargetActorURI == author.Uri && f.State == FollowState.Accepted).ExecuteAnyAsync(token);
+		}
+
+		public async Task<string> Grant(LocalActor author, PostEntity quoted, string quotingUri, string quoterUri, CancellationToken token)
+		{
+			var existing = await DB.Default.Find<QuoteLicence>().Match(l => l.PostId == quoted.ID && l.QuotingObjectURI == quotingUri && l.RevokedAt == null).ExecuteFirstAsync(token);
+			if (existing != default)
+				return LicenceUri(author, existing.ID);
+			var licence = new QuoteLicence { PostId = quoted.ID, AuthorAvatarId = author.Id, QuotingObjectURI = quotingUri, QuoterActorURI = quoterUri };
+			await DB.Default.SaveAsync(licence, token);
+			return LicenceUri(author, licence.ID);
+		}
+
+		public async Task ReceiveRequest(JsonNode request, ForeignAvatar actor, CancellationToken token)
+		{
+			var objectUri = Id(request["object"]);
+			var instrument = request["instrument"];
+			var quotingUri = Id(instrument);
+			if (objectUri == default || quotingUri == default || !Origin.Same(quotingUri, actor.ActorURI)
+				|| instrument is JsonObject embedded && Id(embedded["attributedTo"]) is { } by && by != actor.ActorURI)
+				return;
+			var quoted = await _dbEntities.Posts.Match(p => p.ObjectURI == objectUri && !p.IsFederatedCopy && !p.DeletedAt.HasValue).ExecuteFirstAsync(token);
+			var author = quoted == default ? default : await _localActors.FindById(LocalActorKind.Person, quoted.GroupUserId, token);
+			if (author == default || string.IsNullOrEmpty(actor.InboxURL))
+				return;
+			var answer = new JsonObject
+			{
+				["@context"] = ActivityPubRenderer.Context(),
+				["actor"] = author.Uri,
+				["object"] = Id(request),
+				["to"] = new JsonArray(actor.ActorURI)
+			};
+			if (await MayQuote(quoted, actor.ActorURI, token))
+			{
+				answer["type"] = "Accept";
+				answer["result"] = await Grant(author, quoted, quotingUri, actor.ActorURI, token);
+				answer["id"] = author.ActivityUri($"accept-quote-{Guid.NewGuid():N}");
+			}
+			else
+			{
+				answer["type"] = "Reject";
+				answer["id"] = author.ActivityUri($"reject-quote-{Guid.NewGuid():N}");
+			}
+			await _delivery.Enqueue(author, new[] { actor.InboxURL }, answer, token);
+		}
+
+		public async Task<bool> RevokeLicence(PostEntity quoted, PostEntity quoting, CancellationToken token)
+		{
+			var licence = await DB.Default.Find<QuoteLicence>().Match(l => l.PostId == quoted.ID && l.QuotingObjectURI == quoting.ObjectURI && l.RevokedAt == null).ExecuteFirstAsync(token);
+			var author = licence == default ? default : await _localActors.FindById(LocalActorKind.Person, quoted.GroupUserId, token);
+			if (author == default)
+				return false;
+			await DB.Default.Update<QuoteLicence>().MatchID(licence.ID).Modify(l => l.RevokedAt, DateTime.UtcNow).ExecuteAsync(token);
+			var uri = LicenceUri(author, licence.ID);
+			await Revoke(uri, token);
+			var quoter = quoting.IsFederatedCopy ? await _dbEntities.ForeignAvatars.Match(f => f.ActorURI == quoting.ActorURI).ExecuteFirstAsync(token) : default;
+			var inboxes = (await _delivery.FollowerInboxes(author, token)).Append(quoter?.InboxURL).Where(i => !string.IsNullOrEmpty(i)).Distinct().ToList();
+			if (inboxes.Count > 0)
+				await _delivery.Enqueue(author, inboxes, new JsonObject
+				{
+					["@context"] = ActivityPubRenderer.Context(),
+					["id"] = author.ActivityUri($"revoke-quote-{licence.ID}"),
+					["type"] = "Delete",
+					["actor"] = author.Uri,
+					["object"] = uri,
+					["to"] = new JsonArray(Addressing.Public)
+				}, token);
+			return true;
+		}
+
+		async Task<bool> OurLicence(string stampUri, PostEntity quoting, PostEntity quoted, CancellationToken token)
+		{
+			var marker = stampUri?.LastIndexOf(LicencePath, StringComparison.Ordinal) ?? -1;
+			if (marker < 0 || !stampUri.StartsWith(_localActors.BaseAddress + "/", StringComparison.OrdinalIgnoreCase))
+				return false;
+			var id = stampUri[(marker + LicencePath.Length)..];
+			return await DB.Default.Find<QuoteLicence>().Match(l => l.ID == id && l.PostId == quoted.ID && l.QuotingObjectURI == quoting.ObjectURI && l.RevokedAt == null)
+				.ExecuteAnyAsync(token);
+		}
+
+		public async Task<QuotePermission> Permission(PostEntity quoted, LocalActor author, CancellationToken token)
 		{
 			if (!quoted.IsFederatedCopy)
-				return quoted.GroupUserId == author.Id && quoted.Visibility is PostVisibility.Public or PostVisibility.Unlisted
-					? QuotePermission.Granted
-					: QuotePermission.Denied;
+				return await MayQuote(quoted, author.Uri, token) ? QuotePermission.Granted : QuotePermission.Denied;
 			if (quoted.Visibility is not (PostVisibility.Public or PostVisibility.Unlisted))
 				return QuotePermission.Denied;
 			if (quoted.QuotePolicy is not { } policy)
@@ -140,7 +246,9 @@ namespace PrivaPub.Domain.Statuses
 			var state = note.QuoteDeleted ? QuoteState.Deleted
 				: quoted == default ? QuoteState.Pending
 				: note.QuoteAuthorization != default
-					? !quoted.IsFederatedCopy || !await Verified(note.QuoteAuthorization, post.ObjectURI, quoted, token) ? QuoteState.Unauthorized : QuoteState.Accepted
+					? (quoted.IsFederatedCopy ? await Verified(note.QuoteAuthorization, post.ObjectURI, quoted, token) : await OurLicence(note.QuoteAuthorization, post, quoted, token))
+						? QuoteState.Accepted
+						: QuoteState.Unauthorized
 				: note.QuotesByConsent ? QuoteState.Pending
 				: quoted.Visibility is PostVisibility.Public or PostVisibility.Unlisted ? QuoteState.Accepted
 				: QuoteState.Unauthorized;

PrivaPub/Domain/Statuses/StatusService.cs

@@ -13,6 +13,7 @@ using PrivaPub.Models.Federation;
 using PrivaPub.Models.Group;
 using PrivaPub.Models.Media;
 using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
 using PrivaPub.Models.Social;
 using PrivaPub.StaticServices;
 
@@ -41,6 +42,7 @@ namespace PrivaPub.Domain.Statuses
 		public double? RangeKm { get; init; }
 		public PollDraft Poll { get; init; }
 		public string QuotedStatusId { get; init; }
+		public string QuotePolicy { get; init; }
 	}
 
 	public sealed record StatusOutcome(PostEntity Post, int Status = StatusCodes.Status200OK, string Error = default)
@@ -125,7 +127,7 @@ namespace PrivaPub.Domain.Statuses
 				quoted = await _dbEntities.Posts.Match(p => p.ID == draft.QuotedStatusId && !p.DeletedAt.HasValue && p.ReblogOfPostId == null).ExecuteFirstAsync(token);
 				if (quoted == default || !await VisibilityPolicy.CanSee(quoted, author.Id, token))
 					return StatusOutcome.Fail(StatusCodes.Status404NotFound, "Record not found");
-				quotePermission = _quotes.Permission(quoted, author);
+				quotePermission = await _quotes.Permission(quoted, author, token);
 				if (quotePermission == QuotePermission.Denied)
 					return StatusOutcome.Fail(StatusCodes.Status422UnprocessableEntity, "Validation failed: This post cannot be quoted");
 			}
@@ -190,6 +192,10 @@ namespace PrivaPub.Domain.Statuses
 			post.ID = (string)post.GenerateNewID();
 			post.ObjectURI = author.PostUri(post.ID);
 			post.Url = author.PostHtmlUrl(post.ID);
+			post.LocalQuotePolicy = QuotePolicies.IsKnown(draft.QuotePolicy) ? draft.QuotePolicy : author.Settings.QuotePolicy ?? QuotePolicies.Public;
+			if (quoted is { IsFederatedCopy: false } && post.QuoteState == QuoteState.Accepted
+				&& await _localActors.FindById(LocalActorKind.Person, quoted.GroupUserId, token) is { } quotedAuthor)
+				post.QuoteAuthorizationURI = await _quotes.Grant(quotedAuthor, quoted, post.ObjectURI, author.Uri, token);
 			if (located)
 			{
 				post.Geo = new Coordinates2D(Math.Round(draft.Longitude.Value, 2), Math.Round(draft.Latitude.Value, 2));

PrivaPub/Federation/Controllers/PeasantsController.cs

@@ -199,6 +199,33 @@ namespace PrivaPub.Federation.Controllers
 			return Activity(note);
 		}
 
+		[HttpGet, Route("{actor}/parrot-licences/{licenceId}")]
+		public async Task<IActionResult> ParrotLicence(string actor, string licenceId, CancellationToken token)
+		{
+			var author = await _localActors.FindByUserName(actor, token);
+			var licence = author == default ? default : await DB.Default.Find<QuoteLicence>().Match(l => l.ID == licenceId && l.AuthorAvatarId == author.Id).ExecuteFirstAsync(token);
+			var quoted = licence == default ? default : await _dbEntities.Posts.MatchID(licence.PostId).ExecuteFirstAsync(token);
+			if (quoted == default)
+				return NotFound();
+			var uri = Domain.Statuses.QuoteService.LicenceUri(author, licence.ID);
+			if (licence.RevokedAt.HasValue || quoted.DeletedAt.HasValue)
+				return new ContentResult
+				{
+					Content = new JsonObject { ["@context"] = ActivityPubRenderer.ActivityStreams, ["id"] = uri, ["type"] = "Tombstone", ["formerType"] = "QuoteAuthorization" }.ToJsonString(),
+					ContentType = ActivityContentType,
+					StatusCode = StatusCodes.Status410Gone
+				};
+			return Activity(new JsonObject
+			{
+				["@context"] = ActivityPubRenderer.Context(),
+				["id"] = uri,
+				["type"] = "QuoteAuthorization",
+				["attributedTo"] = author.Uri,
+				["interactingObject"] = licence.QuotingObjectURI,
+				["interactionTarget"] = quoted.ObjectURI
+			});
+		}
+
 		[HttpGet, Route("{actor}/grunts/{activityId}")]
 		public async Task<IActionResult> Grunt(string actor, string activityId, CancellationToken token)
 		{

PrivaPub/Federation/Inbox/Handlers/QuoteRequestHandler.cs

@@ -0,0 +1,21 @@
+using PrivaPub.Domain.Statuses;
+using PrivaPub.Models.User;
+
+using System.Text.Json.Nodes;
+
+namespace PrivaPub.Federation.Inbox.Handlers
+{
+	public class QuoteRequestHandler : IActivityHandler
+	{
+		readonly IQuoteService _quotes;
+
+		public QuoteRequestHandler(IQuoteService quotes)
+		{
+			_quotes = quotes;
+		}
+
+		public string Type => "QuoteRequest";
+
+		public Task Handle(JsonNode activity, ForeignAvatar actor, CancellationToken token) => _quotes.ReceiveRequest(activity, actor, token);
+	}
+}

PrivaPub/Federation/Rendering/ActivityPubRenderer.cs

@@ -43,11 +43,18 @@ namespace PrivaPub.Federation.Rendering
 				["quoteAuthorization"] = new JsonObject { ["@id"] = "https://w3id.org/fep/044f#quoteAuthorization", ["@type"] = "@id" },
 				["QuoteRequest"] = "https://w3id.org/fep/044f#QuoteRequest",
 				["QuoteAuthorization"] = "https://w3id.org/fep/044f#QuoteAuthorization",
+				["interactingObject"] = new JsonObject { ["@id"] = "gts:interactingObject", ["@type"] = "@id" },
+				["interactionTarget"] = new JsonObject { ["@id"] = "gts:interactionTarget", ["@type"] = "@id" },
 				["misskey"] = "https://misskey-hub.net/ns#",
 				["_misskey_quote"] = "misskey:_misskey_quote",
 				["fedibird"] = "http://fedibird.com/ns#",
 				["quoteUri"] = "fedibird:quoteUri",
 				["quoteUrl"] = "as:quoteUrl",
+				["gts"] = "https://gotosocial.org/ns#",
+				["interactionPolicy"] = new JsonObject { ["@id"] = "gts:interactionPolicy", ["@type"] = "@id" },
+				["canQuote"] = new JsonObject { ["@id"] = "gts:canQuote", ["@type"] = "@id" },
+				["automaticApproval"] = new JsonObject { ["@id"] = "gts:automaticApproval", ["@type"] = "@id" },
+				["manualApproval"] = new JsonObject { ["@id"] = "gts:manualApproval", ["@type"] = "@id" },
 				["litepub"] = "http://litepub.social/ns#",
 				["EmojiReact"] = "litepub:EmojiReact",
 				["focalPoint"] = new JsonObject { ["@container"] = "@list", ["@id"] = "toot:focalPoint" },
@@ -188,6 +195,9 @@ namespace PrivaPub.Federation.Rendering
 			};
 		}
 
+		public static string QuotableBy(PostEntity post) =>
+			post.Visibility is PostVisibility.Public or PostVisibility.Unlisted ? post.LocalQuotePolicy ?? Models.User.QuotePolicies.Nobody : Models.User.QuotePolicies.Nobody;
+
 		static void AddQuote(JsonObject note, PostEntity post, ref string content)
 		{
 			if (string.IsNullOrEmpty(post.QuoteURI))
@@ -262,6 +272,19 @@ namespace PrivaPub.Federation.Rendering
 					.ToArray())
 			};
 			AddQuote(note, post, ref content);
+			if (!post.IsFederatedCopy)
+				note["interactionPolicy"] = new JsonObject
+				{
+					["canQuote"] = new JsonObject
+					{
+						["automaticApproval"] = new JsonArray((JsonNode)(QuotableBy(post) switch
+						{
+							Models.User.QuotePolicies.Public => Objects.Addressing.Public,
+							Models.User.QuotePolicies.Followers => author.Followers,
+							_ => author.Uri
+						}))
+					}
+				};
 			note["content"] = content;
 			if (!string.IsNullOrEmpty(post.Language))
 				note["contentMap"] = new JsonObject { [post.Language] = content };

PrivaPub/Infrastructure/Data/Indexes.cs

@@ -116,6 +116,7 @@ namespace PrivaPub.Infrastructure.Data
 			await DB.Default.Index<Reaction>().Key(r => r.PostId, KeyType.Ascending).Key(r => r.ActorURI, KeyType.Ascending).Key(r => r.Emoji, KeyType.Ascending)
 				.Option(o => o.Unique = true).CreateAsync(token);
 			await Plain<Reaction>(token, r => r.ActivityURI);
+			await DB.Default.Index<QuoteLicence>().Key(l => l.PostId, KeyType.Ascending).Key(l => l.QuotingObjectURI, KeyType.Ascending).CreateAsync(token);
 			await Unique<Domain.Content.LinkPreview>(p => p.Url, Builders<Domain.Content.LinkPreview>.Filter.Type(p => p.Url, BsonType.String), token);
 		}
 

PrivaPub/Middleware/SocialPubConfigurations.cs

@@ -78,6 +78,7 @@ namespace PrivaPub.Middleware
 				.AddSingleton<IActivityHandler, LikeHandler>()
 				.AddSingleton<IActivityHandler, DislikeHandler>()
 				.AddSingleton<IActivityHandler, EmojiReactHandler>()
+				.AddSingleton<IActivityHandler, QuoteRequestHandler>()
 				.AddSingleton<IReactions, Reactions>()
 				.AddSingleton<LinkPreviews>()
 				.AddSingleton<ILinkPreviews>(services => services.GetRequiredService<LinkPreviews>())

PrivaPub/Models/Federation/QuoteLicence.cs

@@ -0,0 +1,14 @@
+using MongoDB.Entities;
+
+namespace PrivaPub.Models.Federation
+{
+	public class QuoteLicence : Entity
+	{
+		public string PostId { get; set; }//the quoted local post
+		public string AuthorAvatarId { get; set; }
+		public string QuotingObjectURI { get; set; }
+		public string QuoterActorURI { get; set; }
+		public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+		public DateTime? RevokedAt { get; set; }
+	}
+}

PrivaPub/Models/Post/Post.cs

@@ -60,7 +60,8 @@ namespace PrivaPub.Models.Post
 		public string QuotedPostId { get; set; }//our copy of the quoted post, once fetched
 		public QuoteState QuoteState { get; set; }
 		public string QuoteAuthorizationURI { get; set; }//FEP-044f: the quoted author's stamp
-		public bool QuoteByConsent { get; set; }//our quote of a post whose server asks for consent (FEP-044f), so `quote` is sent
+		public bool QuoteByConsent { get; set; }
+		public string LocalQuotePolicy { get; set; }//who may quote this local post: QuotePolicies.Public, Followers or Nobody//our quote of a post whose server asks for consent (FEP-044f), so `quote` is sent
 		public int QuotesCount { get; set; }
 		[BsonIgnoreIfNull]
 		public InteractionRule QuotePolicy { get; set; }//a remote post's interactionPolicy.canQuote; null when it states none

PrivaPub/Models/User/Avatar.cs

@@ -110,6 +110,16 @@ namespace PrivaPub.Models.User
 		public string DefaultVisibility { get; set; } = "public";
 		public bool DefaultSensitive { get; set; }
 		public string DefaultLanguage { get; set; }
+		public string QuotePolicy { get; set; } = QuotePolicies.Public;//owner decision: anyone may quote a public post, automatically
+	}
+
+	public static class QuotePolicies
+	{
+		public const string Public = "public";
+		public const string Followers = "followers";
+		public const string Nobody = "nobody";
+
+		public static bool IsKnown(string value) => value is Public or Followers or Nobody;
 	}
 
 	public enum AvatarServer