diff --git a/test/activitypub/inbox.js b/test/activitypub/inbox.js
new file mode 100644
index 0000000000..91b0c76e46
--- /dev/null
+++ b/test/activitypub/inbox.js
@@ -0,0 +1,479 @@
+'use strict';
+
+const assert = require('assert');
+const nconf = require('nconf');
+
+const db = require('../mocks/databasemock');
+const meta = require('../../src/meta');
+const install = require('../../src/install');
+const user = require('../../src/user');
+const categories = require('../../src/categories');
+const topics = require('../../src/topics');
+const posts = require('../../src/posts');
+const activitypub = require('../../src/activitypub');
+const utils = require('../../src/utils');
+
+const helpers = require('./helpers');
+
+describe('Inbox', () => {
+	before(async () => {
+		meta.config.activitypubEnabled = 1;
+		await install.giveWorldPrivileges();
+	});
+
+	describe('Inbox handling', () => {
+		describe('helper self-check', () => {
+			it('should generate a Like activity', () => {
+				const object = utils.generateUUID();
+				const { id: actor } = helpers.mocks.person();
+				const { activity } = helpers.mocks.like({
+					object,
+					actor,
+				});
+
+				assert.deepStrictEqual(activity, {
+					'@context': 'https://www.w3.org/ns/activitystreams',
+					id: `${helpers.mocks._baseUrl}/like/${encodeURIComponent(object)}`,
+					type: 'Like',
+					actor,
+					object,
+				});
+			});
+
+			it('should generate an Announce activity wrapping a Like activity', () => {
+				const object = utils.generateUUID();
+				const { id: actor } = helpers.mocks.person();
+				const { activity: like } = helpers.mocks.like({
+					object,
+					actor,
+				});
+				const { id: gActor } = helpers.mocks.group();
+				const { activity } = helpers.mocks.announce({
+					actor: gActor,
+					object: like,
+				});
+
+				assert.deepStrictEqual(activity, {
+					'@context': 'https://www.w3.org/ns/activitystreams',
+					id: `${helpers.mocks._baseUrl}/announce/${encodeURIComponent(like.id)}`,
+					type: 'Announce',
+					to: [ 'https://www.w3.org/ns/activitystreams#Public' ],
+					cc: [
+						`${gActor}/followers`,
+					],
+					actor: gActor,
+					object: like,
+				});
+			});
+		});
+
+		describe('from a banned account', () => {
+			before(async function () {
+				const { id: bannedUid } = helpers.mocks.person();
+				this.bannedUid = bannedUid;
+
+				const { note } = helpers.mocks.note({
+					attributedTo: bannedUid,
+				});
+
+				const uid = await user.create({ username: utils.generateUUID() });
+				const { id: boosterUid } = helpers.mocks.person();
+				await db.sortedSetAdd(`followersRemote:${boosterUid}`, Date.now(), uid);
+				const { activity } = helpers.mocks.announce({
+					actor: boosterUid,
+					object: note,
+				});
+				this.activity = activity;
+				this.pid = note.id;
+
+				await user.bans.ban(bannedUid, 0, 'testing');
+			});
+
+			it('should list the remote user as banned, when queried', async function () {
+				const isBanned = await user.bans.isBanned(this.bannedUid);
+				assert.strictEqual(isBanned, true);
+			});
+
+			// Can't actually test the middleware because I can't sign a request for a test
+
+			it('should not assert a note if authored by a banned user (boosted by third-party)', async function () {
+				await activitypub.inbox.announce({
+					body: this.activity,
+				});
+
+				const exists = await posts.exists(this.pid);
+				assert.strictEqual(exists, false);
+			});
+		});
+
+		describe('Create', () => {
+			let uid;
+			let cid;
+
+			before(async () => {
+				uid = await user.create({ username: utils.generateUUID() });
+			});
+
+			describe('(Note)', () => {
+				it('should create a new topic in cid -1', async () => {
+					const { note, id } = helpers.mocks.note();
+					const { activity } = helpers.mocks.create(note);
+
+					await db.sortedSetAdd(`followersRemote:${note.attributedTo}`, Date.now(), uid);
+					await activitypub.inbox.create({ body: activity });
+
+					assert(await posts.exists(id));
+
+					const cid = await posts.getCidByPid(id);
+					assert.strictEqual(cid, -1);
+				});
+
+				it('should not append to the tids_read sorted set', async () => {
+					const { note, id } = helpers.mocks.note();
+					const { activity } = helpers.mocks.create(note);
+
+					await db.sortedSetAdd(`followersRemote:${note.attributedTo}`, Date.now(), uid);
+					await activitypub.inbox.create({ body: activity });
+
+					const exists = await db.exists(`uid:${note.attributedTo}:tids_read`);
+					assert(!exists);
+				});
+
+				it('should create a new topic in a remote category if addressed (category same-origin)', async () => {
+					const { id: remoteCid } = helpers.mocks.group();
+					const { note, id } = helpers.mocks.note({
+						audience: [remoteCid],
+					});
+					const { activity } = helpers.mocks.create(note);
+
+					await activitypub.inbox.create({ body: activity });
+
+					assert(await posts.exists(id));
+
+					const cid = await posts.getCidByPid(id);
+					assert.strictEqual(cid, remoteCid);
+				});
+
+				it('should create a new topic in cid -1 if a non-same origin remote category is addressed', async function () {
+					const { id: remoteCid } = helpers.mocks.group({
+						id: `https://example.com/${utils.generateUUID()}`,
+					});
+					const { note, id } = helpers.mocks.note({
+						audience: [remoteCid],
+					});
+					const { activity } = helpers.mocks.create(note);
+					try {
+						await activitypub.inbox.create({ body: activity });
+					} catch (err) {
+						assert(false);
+					}
+
+					assert(await posts.exists(id));
+					const cid = await posts.getCidByPid(id);
+					assert.strictEqual(cid, -1);
+				});
+			});
+
+			describe('(Like)', () => {
+				let pid;
+				let voterUid;
+
+				before(async () => {
+					({ cid } = await categories.create({ name: utils.generateUUID() }));
+					const { postData } = await topics.post({
+						uid,
+						cid,
+						title: utils.generateUUID(),
+						content: utils.generateUUID(),
+					});
+					pid = postData.pid;
+					const object = await activitypub.mocks.notes.public(postData);
+					const { activity } = helpers.mocks.like({ object });
+					voterUid = activity.actor;
+					await activitypub.inbox.like({ body: activity });
+				});
+
+				it('should increment a like for the post', async () => {
+					const voted = await posts.hasVoted(pid, voterUid);
+					const count = await posts.getPostField(pid, 'upvotes');
+					assert(voted);
+					assert.strictEqual(count, 1);
+				});
+
+				it('should not append to the uid upvotes zset', async () => {
+					const exists = await db.exists(`uid:${voterUid}:upvote`);
+					assert(!exists);
+				});
+			});
+		});
+
+		describe('Announce', () => {
+			let cid;
+
+			before(async () => {
+				({ cid } = await categories.create({ name: utils.generateUUID() }));
+			});
+
+			describe('(Create)', () => {
+				it('should create a new topic in a remote category if addressed', async () => {
+					const { id: remoteCid } = helpers.mocks.group();
+					const { id, note } = helpers.mocks.note({
+						audience: [remoteCid],
+					});
+					let { activity } = helpers.mocks.create(note);
+					({ activity } = helpers.mocks.announce({ actor: remoteCid, object: activity }));
+
+					await activitypub.inbox.announce({ body: activity });
+
+					assert(await posts.exists(id));
+
+					const cid = await posts.getCidByPid(id);
+					assert.strictEqual(cid, remoteCid);
+				});
+			});
+
+			describe('(Create) or (Note) referencing local post', () => {
+				let uid;
+				let topicData;
+				let postData;
+				let localNote;
+				let announces = 0;
+
+				before(async () => {
+					uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+					({ topicData, postData } = await topics.post({
+						cid,
+						uid,
+						title: utils.generateUUID(),
+						content: utils.generateUUID(),
+					}));
+					localNote = await activitypub.mocks.notes.public(postData);
+				});
+
+				it('should increment announces counter when a remote user shares', async () => {
+					const { id } = helpers.mocks.person();
+					const { activity } = helpers.mocks.announce({
+						actor: id,
+						object: localNote,
+						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
+					});
+
+					await activitypub.inbox.announce({ body: activity });
+					announces += 1;
+
+					const count = await posts.getPostField(topicData.mainPid, 'announces');
+					assert.strictEqual(count, announces);
+				});
+
+				it('should contain the remote user announcer id in the post announces zset', async () => {
+					const { id } = helpers.mocks.person();
+					const { activity } = helpers.mocks.announce({
+						actor: id,
+						object: localNote,
+						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
+					});
+
+					await activitypub.inbox.announce({ body: activity });
+					announces += 1;
+
+					const exists = await db.isSortedSetMember(`pid:${topicData.mainPid}:announces`, id);
+					assert(exists);
+				});
+
+				it('should NOT increment announces counter when a remote category shares', async () => {
+					const { id } = helpers.mocks.group();
+					const { activity } = helpers.mocks.announce({
+						actor: id,
+						object: localNote,
+						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
+					});
+
+					await activitypub.inbox.announce({ body: activity });
+
+					const count = await posts.getPostField(topicData.mainPid, 'announces');
+					assert.strictEqual(count, announces);
+				});
+
+				it('should NOT contain the remote category announcer id in the post announces zset', async () => {
+					const { id } = helpers.mocks.group();
+					const { activity } = helpers.mocks.announce({
+						actor: id,
+						object: localNote,
+						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
+					});
+
+					await activitypub.inbox.announce({ body: activity });
+
+					const exists = await db.isSortedSetMember(`pid:${topicData.mainPid}:announces`, id);
+					assert(!exists);
+				});
+			});
+
+			describe('(Note)', () => {
+				it('should create a new topic in cid -1 if category not addressed', async () => {
+					const { note } = helpers.mocks.note();
+					await activitypub.actors.assert([note.attributedTo]);
+					const { activity } = helpers.mocks.announce({
+						object: note,
+					});
+					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+					await db.sortedSetAdd(`followersRemote:${activity.actor}`, Date.now(), uid);
+
+					const beforeCount = await db.sortedSetCard(`cid:-1:tids`);
+					await activitypub.inbox.announce({ body: activity });
+					const count = await db.sortedSetCard(`cid:-1:tids`);
+
+					assert.strictEqual(count, beforeCount + 1);
+				});
+
+				it('should create a new topic in local category', async () => {
+					const { note } = helpers.mocks.note({
+						cc: [`${nconf.get('url')}/category/${cid}`],
+					});
+					await activitypub.actors.assert([note.attributedTo]);
+					const { activity } = helpers.mocks.announce({
+						object: note,
+					});
+					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+					await db.sortedSetAdd(`followersRemote:${activity.actor}`, Date.now(), uid);
+
+					const beforeCount = await db.sortedSetCard(`cid:${cid}:tids`);
+					await activitypub.inbox.announce({ body: activity });
+					const count = await db.sortedSetCard(`cid:${cid}:tids`);
+
+					assert.strictEqual(count, beforeCount + 1);
+				});
+			});
+
+			describe('(Like)', () => {
+				it('should upvote a local post', async () => {
+					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+					const { postData } = await topics.post({
+						cid,
+						uid,
+						title: utils.generateUUID(),
+						content: utils.generateUUID(),
+					});
+
+					const { activity: like } = helpers.mocks.like({
+						object: `${nconf.get('url')}/post/${postData.pid}`,
+					});
+					const { activity } = helpers.mocks.announce({
+						object: like,
+					});
+
+					let { upvotes } = await posts.getPostFields(postData.pid, 'upvotes');
+					assert.strictEqual(upvotes, 0);
+
+					await activitypub.inbox.announce({ body: activity });
+					({ upvotes } = await posts.getPostFields(postData.pid, 'upvotes'));
+					assert.strictEqual(upvotes, 1);
+				});
+
+				it('should upvote an asserted remote post', async () => {
+					const { id } = helpers.mocks.note();
+					await activitypub.notes.assert(0, id, { skipChecks: true });
+					const { activity: like } = helpers.mocks.like({
+						object: id,
+					});
+					const { activity } = helpers.mocks.announce({
+						object: like,
+					});
+
+					let { upvotes } = await posts.getPostFields(id, 'upvotes');
+					assert.strictEqual(upvotes, 0);
+
+					await activitypub.inbox.announce({ body: activity });
+
+					({ upvotes } = await posts.getPostFields(id, 'upvotes'));
+					assert.strictEqual(upvotes, 1);
+				});
+			});
+
+			describe('(Update)', () => {
+				it('should update a note\'s content', async () => {
+					const { id: actor } = helpers.mocks.person();
+					const { id, note } = helpers.mocks.note({ attributedTo: actor });
+					await activitypub.notes.assert(0, id, { skipChecks: true });
+					note.content = utils.generateUUID();
+					const { activity: update } = helpers.mocks.update({ object: note });
+					const { activity } = helpers.mocks.announce({ object: update });
+
+					await activitypub.inbox.announce({ body: activity });
+
+					const content = await posts.getPostField(id, 'content');
+					assert.strictEqual(content, note.content);
+				});
+			});
+		});
+	});
+
+	describe('Inbox Synchronization', () => {
+		let cid;
+		let uid;
+		let topicData;
+
+		before(async () => {
+			({ cid } = await categories.create({ name: utils.generateUUID().slice(0, 8) }));
+		});
+
+		beforeEach(async () => {
+			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+			({ topicData } = await topics.post({
+				cid,
+				uid,
+				title: utils.generateUUID(),
+				content: utils.generateUUID(),
+			}));
+		});
+
+		it('should add a topic to a user\'s inbox if user is a recipient in OP', async () => {
+			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+
+		it('should add a topic to a user\'s inbox if a user is a recipient in a reply', async () => {
+			const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
+			const { pid } = await topics.reply({
+				tid: topicData.tid,
+				uid,
+				content: utils.generateUUID(),
+			});
+			await db.setAdd(`post:${pid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+
+		it('should maintain a list of recipients at the topic level', async () => {
+			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const [isRecipient, count] = await Promise.all([
+				db.isSetMember(`tid:${topicData.tid}:recipients`, uid),
+				db.setCount(`tid:${topicData.tid}:recipients`),
+			]);
+
+			assert(isRecipient);
+			assert.strictEqual(count, 1);
+		});
+
+		it('should add topic to a user\'s inbox if it is explicitly passed in as an argument', async () => {
+			await activitypub.notes.syncUserInboxes(topicData.tid, uid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, true);
+		});
+
+		it('should remove a topic from a user\'s inbox if that user is no longer a recipient in any contained posts', async () => {
+			await activitypub.notes.syncUserInboxes(topicData.tid, uid);
+			await activitypub.notes.syncUserInboxes(topicData.tid);
+			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
+
+			assert.strictEqual(inboxed, false);
+		});
+	});
+});
diff --git a/test/activitypub/notes.js b/test/activitypub/notes.js
index 470c7c821c..bded9c322f 100644
--- a/test/activitypub/notes.js
+++ b/test/activitypub/notes.js
@@ -384,462 +384,6 @@ describe('Notes', () => {
 		});
 	});
 
-	describe('Inbox handling', () => {
-		describe('helper self-check', () => {
-			it('should generate a Like activity', () => {
-				const object = utils.generateUUID();
-				const { id: actor } = helpers.mocks.person();
-				const { activity } = helpers.mocks.like({
-					object,
-					actor,
-				});
-
-				assert.deepStrictEqual(activity, {
-					'@context': 'https://www.w3.org/ns/activitystreams',
-					id: `${helpers.mocks._baseUrl}/like/${encodeURIComponent(object)}`,
-					type: 'Like',
-					actor,
-					object,
-				});
-			});
-
-			it('should generate an Announce activity wrapping a Like activity', () => {
-				const object = utils.generateUUID();
-				const { id: actor } = helpers.mocks.person();
-				const { activity: like } = helpers.mocks.like({
-					object,
-					actor,
-				});
-				const { id: gActor } = helpers.mocks.group();
-				const { activity } = helpers.mocks.announce({
-					actor: gActor,
-					object: like,
-				});
-
-				assert.deepStrictEqual(activity, {
-					'@context': 'https://www.w3.org/ns/activitystreams',
-					id: `${helpers.mocks._baseUrl}/announce/${encodeURIComponent(like.id)}`,
-					type: 'Announce',
-					to: [ 'https://www.w3.org/ns/activitystreams#Public' ],
-					cc: [
-						`${gActor}/followers`,
-					],
-					actor: gActor,
-					object: like,
-				});
-			});
-		});
-
-		describe('from a banned account', () => {
-			before(async function () {
-				const { id: bannedUid } = helpers.mocks.person();
-				this.bannedUid = bannedUid;
-
-				const { note } = helpers.mocks.note({
-					attributedTo: bannedUid,
-				});
-
-				const uid = await user.create({ username: utils.generateUUID() });
-				const { id: boosterUid } = helpers.mocks.person();
-				await db.sortedSetAdd(`followersRemote:${boosterUid}`, Date.now(), uid);
-				const { activity } = helpers.mocks.announce({
-					actor: boosterUid,
-					object: note,
-				});
-				this.activity = activity;
-				this.pid = note.id;
-
-				await user.bans.ban(bannedUid, 0, 'testing');
-			});
-
-			it('should list the remote user as banned, when queried', async function () {
-				const isBanned = await user.bans.isBanned(this.bannedUid);
-				assert.strictEqual(isBanned, true);
-			});
-
-			// Can't actually test the middleware because I can't sign a request for a test
-
-			it('should not assert a note if authored by a banned user (boosted by third-party)', async function () {
-				await activitypub.inbox.announce({
-					body: this.activity,
-				});
-
-				const exists = await posts.exists(this.pid);
-				assert.strictEqual(exists, false);
-			});
-		});
-
-		describe('Create', () => {
-			let uid;
-			let cid;
-
-			before(async () => {
-				uid = await user.create({ username: utils.generateUUID() });
-			});
-
-			describe('(Note)', () => {
-				it('should create a new topic in cid -1', async () => {
-					const { note, id } = helpers.mocks.note();
-					const { activity } = helpers.mocks.create(note);
-
-					await db.sortedSetAdd(`followersRemote:${note.attributedTo}`, Date.now(), uid);
-					await activitypub.inbox.create({ body: activity });
-
-					assert(await posts.exists(id));
-
-					const cid = await posts.getCidByPid(id);
-					assert.strictEqual(cid, -1);
-				});
-
-				it('should not append to the tids_read sorted set', async () => {
-					const { note, id } = helpers.mocks.note();
-					const { activity } = helpers.mocks.create(note);
-
-					await db.sortedSetAdd(`followersRemote:${note.attributedTo}`, Date.now(), uid);
-					await activitypub.inbox.create({ body: activity });
-
-					const exists = await db.exists(`uid:${note.attributedTo}:tids_read`);
-					assert(!exists);
-				});
-
-				it('should create a new topic in a remote category if addressed (category same-origin)', async () => {
-					const { id: remoteCid } = helpers.mocks.group();
-					const { note, id } = helpers.mocks.note({
-						audience: [remoteCid],
-					});
-					const { activity } = helpers.mocks.create(note);
-
-					await activitypub.inbox.create({ body: activity });
-
-					assert(await posts.exists(id));
-
-					const cid = await posts.getCidByPid(id);
-					assert.strictEqual(cid, remoteCid);
-				});
-
-				it('should create a new topic in cid -1 if a non-same origin remote category is addressed', async function () {
-					const { id: remoteCid } = helpers.mocks.group({
-						id: `https://example.com/${utils.generateUUID()}`,
-					});
-					const { note, id } = helpers.mocks.note({
-						audience: [remoteCid],
-					});
-					const { activity } = helpers.mocks.create(note);
-					try {
-						await activitypub.inbox.create({ body: activity });
-					} catch (err) {
-						assert(false);
-					}
-
-					assert(await posts.exists(id));
-					const cid = await posts.getCidByPid(id);
-					assert.strictEqual(cid, -1);
-				});
-			});
-
-			describe('(Like)', () => {
-				let pid;
-				let voterUid;
-
-				before(async () => {
-					({ cid } = await categories.create({ name: utils.generateUUID() }));
-					const { postData } = await topics.post({
-						uid,
-						cid,
-						title: utils.generateUUID(),
-						content: utils.generateUUID(),
-					});
-					pid = postData.pid;
-					const object = await activitypub.mocks.notes.public(postData);
-					const { activity } = helpers.mocks.like({ object });
-					voterUid = activity.actor;
-					await activitypub.inbox.like({ body: activity });
-				});
-
-				it('should increment a like for the post', async () => {
-					const voted = await posts.hasVoted(pid, voterUid);
-					const count = await posts.getPostField(pid, 'upvotes');
-					assert(voted);
-					assert.strictEqual(count, 1);
-				});
-
-				it('should not append to the uid upvotes zset', async () => {
-					const exists = await db.exists(`uid:${voterUid}:upvote`);
-					assert(!exists);
-				});
-			});
-		});
-
-		describe('Announce', () => {
-			let cid;
-
-			before(async () => {
-				({ cid } = await categories.create({ name: utils.generateUUID() }));
-			});
-
-			describe('(Create)', () => {
-				it('should create a new topic in a remote category if addressed', async () => {
-					const { id: remoteCid } = helpers.mocks.group();
-					const { id, note } = helpers.mocks.note({
-						audience: [remoteCid],
-					});
-					let { activity } = helpers.mocks.create(note);
-					({ activity } = helpers.mocks.announce({ actor: remoteCid, object: activity }));
-
-					await activitypub.inbox.announce({ body: activity });
-
-					assert(await posts.exists(id));
-
-					const cid = await posts.getCidByPid(id);
-					assert.strictEqual(cid, remoteCid);
-				});
-			});
-
-			describe('(Create) or (Note) referencing local post', () => {
-				let uid;
-				let topicData;
-				let postData;
-				let localNote;
-				let announces = 0;
-
-				before(async () => {
-					uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-					({ topicData, postData } = await topics.post({
-						cid,
-						uid,
-						title: utils.generateUUID(),
-						content: utils.generateUUID(),
-					}));
-					localNote = await activitypub.mocks.notes.public(postData);
-				});
-
-				it('should increment announces counter when a remote user shares', async () => {
-					const { id } = helpers.mocks.person();
-					const { activity } = helpers.mocks.announce({
-						actor: id,
-						object: localNote,
-						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
-					});
-
-					await activitypub.inbox.announce({ body: activity });
-					announces += 1;
-
-					const count = await posts.getPostField(topicData.mainPid, 'announces');
-					assert.strictEqual(count, announces);
-				});
-
-				it('should contain the remote user announcer id in the post announces zset', async () => {
-					const { id } = helpers.mocks.person();
-					const { activity } = helpers.mocks.announce({
-						actor: id,
-						object: localNote,
-						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
-					});
-
-					await activitypub.inbox.announce({ body: activity });
-					announces += 1;
-
-					const exists = await db.isSortedSetMember(`pid:${topicData.mainPid}:announces`, id);
-					assert(exists);
-				});
-
-				it('should NOT increment announces counter when a remote category shares', async () => {
-					const { id } = helpers.mocks.group();
-					const { activity } = helpers.mocks.announce({
-						actor: id,
-						object: localNote,
-						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
-					});
-
-					await activitypub.inbox.announce({ body: activity });
-
-					const count = await posts.getPostField(topicData.mainPid, 'announces');
-					assert.strictEqual(count, announces);
-				});
-
-				it('should NOT contain the remote category announcer id in the post announces zset', async () => {
-					const { id } = helpers.mocks.group();
-					const { activity } = helpers.mocks.announce({
-						actor: id,
-						object: localNote,
-						cc: [`${nconf.get('url')}/uid/${topicData.uid}`],
-					});
-
-					await activitypub.inbox.announce({ body: activity });
-
-					const exists = await db.isSortedSetMember(`pid:${topicData.mainPid}:announces`, id);
-					assert(!exists);
-				});
-			});
-
-			describe('(Note)', () => {
-				it('should create a new topic in cid -1 if category not addressed', async () => {
-					const { note } = helpers.mocks.note();
-					await activitypub.actors.assert([note.attributedTo]);
-					const { activity } = helpers.mocks.announce({
-						object: note,
-					});
-					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-					await db.sortedSetAdd(`followersRemote:${activity.actor}`, Date.now(), uid);
-
-					const beforeCount = await db.sortedSetCard(`cid:-1:tids`);
-					await activitypub.inbox.announce({ body: activity });
-					const count = await db.sortedSetCard(`cid:-1:tids`);
-
-					assert.strictEqual(count, beforeCount + 1);
-				});
-
-				it('should create a new topic in local category', async () => {
-					const { note } = helpers.mocks.note({
-						cc: [`${nconf.get('url')}/category/${cid}`],
-					});
-					await activitypub.actors.assert([note.attributedTo]);
-					const { activity } = helpers.mocks.announce({
-						object: note,
-					});
-					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-					await db.sortedSetAdd(`followersRemote:${activity.actor}`, Date.now(), uid);
-
-					const beforeCount = await db.sortedSetCard(`cid:${cid}:tids`);
-					await activitypub.inbox.announce({ body: activity });
-					const count = await db.sortedSetCard(`cid:${cid}:tids`);
-
-					assert.strictEqual(count, beforeCount + 1);
-				});
-			});
-
-			describe('(Like)', () => {
-				it('should upvote a local post', async () => {
-					const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-					const { postData } = await topics.post({
-						cid,
-						uid,
-						title: utils.generateUUID(),
-						content: utils.generateUUID(),
-					});
-
-					const { activity: like } = helpers.mocks.like({
-						object: `${nconf.get('url')}/post/${postData.pid}`,
-					});
-					const { activity } = helpers.mocks.announce({
-						object: like,
-					});
-
-					let { upvotes } = await posts.getPostFields(postData.pid, 'upvotes');
-					assert.strictEqual(upvotes, 0);
-
-					await activitypub.inbox.announce({ body: activity });
-					({ upvotes } = await posts.getPostFields(postData.pid, 'upvotes'));
-					assert.strictEqual(upvotes, 1);
-				});
-
-				it('should upvote an asserted remote post', async () => {
-					const { id } = helpers.mocks.note();
-					await activitypub.notes.assert(0, id, { skipChecks: true });
-					const { activity: like } = helpers.mocks.like({
-						object: id,
-					});
-					const { activity } = helpers.mocks.announce({
-						object: like,
-					});
-
-					let { upvotes } = await posts.getPostFields(id, 'upvotes');
-					assert.strictEqual(upvotes, 0);
-
-					await activitypub.inbox.announce({ body: activity });
-
-					({ upvotes } = await posts.getPostFields(id, 'upvotes'));
-					assert.strictEqual(upvotes, 1);
-				});
-			});
-
-			describe('(Update)', () => {
-				it('should update a note\'s content', async () => {
-					const { id: actor } = helpers.mocks.person();
-					const { id, note } = helpers.mocks.note({ attributedTo: actor });
-					await activitypub.notes.assert(0, id, { skipChecks: true });
-					note.content = utils.generateUUID();
-					const { activity: update } = helpers.mocks.update({ object: note });
-					const { activity } = helpers.mocks.announce({ object: update });
-
-					await activitypub.inbox.announce({ body: activity });
-
-					const content = await posts.getPostField(id, 'content');
-					assert.strictEqual(content, note.content);
-				});
-			});
-		});
-	});
-
-	describe('Inbox Synchronization', () => {
-		let cid;
-		let uid;
-		let topicData;
-
-		before(async () => {
-			({ cid } = await categories.create({ name: utils.generateUUID().slice(0, 8) }));
-		});
-
-		beforeEach(async () => {
-			uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-			({ topicData } = await topics.post({
-				cid,
-				uid,
-				title: utils.generateUUID(),
-				content: utils.generateUUID(),
-			}));
-		});
-
-		it('should add a topic to a user\'s inbox if user is a recipient in OP', async () => {
-			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
-			await activitypub.notes.syncUserInboxes(topicData.tid);
-			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
-
-			assert.strictEqual(inboxed, true);
-		});
-
-		it('should add a topic to a user\'s inbox if a user is a recipient in a reply', async () => {
-			const uid = await user.create({ username: utils.generateUUID().slice(0, 10) });
-			const { pid } = await topics.reply({
-				tid: topicData.tid,
-				uid,
-				content: utils.generateUUID(),
-			});
-			await db.setAdd(`post:${pid}:recipients`, [uid]);
-			await activitypub.notes.syncUserInboxes(topicData.tid);
-			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
-
-			assert.strictEqual(inboxed, true);
-		});
-
-		it('should maintain a list of recipients at the topic level', async () => {
-			await db.setAdd(`post:${topicData.mainPid}:recipients`, [uid]);
-			await activitypub.notes.syncUserInboxes(topicData.tid);
-			const [isRecipient, count] = await Promise.all([
-				db.isSetMember(`tid:${topicData.tid}:recipients`, uid),
-				db.setCount(`tid:${topicData.tid}:recipients`),
-			]);
-
-			assert(isRecipient);
-			assert.strictEqual(count, 1);
-		});
-
-		it('should add topic to a user\'s inbox if it is explicitly passed in as an argument', async () => {
-			await activitypub.notes.syncUserInboxes(topicData.tid, uid);
-			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
-
-			assert.strictEqual(inboxed, true);
-		});
-
-		it('should remove a topic from a user\'s inbox if that user is no longer a recipient in any contained posts', async () => {
-			await activitypub.notes.syncUserInboxes(topicData.tid, uid);
-			await activitypub.notes.syncUserInboxes(topicData.tid);
-			const inboxed = await db.isSortedSetMember(`uid:${uid}:inbox`, topicData.tid);
-
-			assert.strictEqual(inboxed, false);
-		});
-	});
-
 	describe('Deletion', () => {
 		let cid;
 		let uid;