diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index b86f3516fe..f99b32d8c9 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -81,17 +81,11 @@ Mocks.post = async (objects) => {
 
 		const {
 			id: pid,
-			published,
-			updated,
 			attributedTo: uid,
-			// conversation,
-			name,
-			content,
-			sourceContent,
 			inReplyTo: toPid,
-			to,
-			cc,
-			attachment,
+			published, updated, name, content, sourceContent,
+			to, cc, attachment, tag,
+			// conversation, // mastodon-specific, ignored.
 		} = object;
 
 		const timestamp = new Date(published).getTime();
@@ -110,7 +104,7 @@ Mocks.post = async (objects) => {
 
 			edited,
 			editor: edited ? uid : undefined,
-			_activitypub: { to, cc, attachment },
+			_activitypub: { to, cc, attachment, tag },
 		};
 
 		return payload;
diff --git a/src/activitypub/notes.js b/src/activitypub/notes.js
index f3cf0220d3..c2beef2055 100644
--- a/src/activitypub/notes.js
+++ b/src/activitypub/notes.js
@@ -10,8 +10,6 @@ const user = require('../user');
 const topics = require('../topics');
 const posts = require('../posts');
 const utils = require('../utils');
-// const pubsub = require('../pubsub');
-const slugify = require('../slugify');
 
 const activitypub = module.parent.exports;
 const Notes = module.exports;
@@ -204,20 +202,22 @@ Notes.assertTopic = async (uid, id) => {
 		return null;
 	}
 
-	let { pid: mainPid, tid, uid: authorId, timestamp, name, content } = chain[chain.length - 1];
+	const mainPost = chain[chain.length - 1];
+	let { pid: mainPid, tid, uid: authorId, timestamp, name, content } = mainPost;
 	const hasTid = !!tid;
 
-	const members = await db.isSortedSetMembers(`tid:${tid}:posts`, chain.map(p => p.pid));
+	const members = await db.isSortedSetMembers(`tid:${tid}:posts`, chain.slice(0, -1).map(p => p.pid));
+	members.push(await posts.exists(mainPid));
 	if (tid && members.every(Boolean)) {
 		// All cached, return early.
-		winston.info('[notes/assertTopic] No new notes to process.');
+		winston.verbose('[notes/assertTopic] No new notes to process.');
 		return tid;
 	}
 
 	let cid;
 	let title;
 	if (hasTid) {
-		({ cid, title, mainPid } = await topics.getTopicFields(tid, ['cid', 'title', 'mainPid']));
+		({ cid, title, mainPid } = await topics.getTopicFields(tid, ['tid', 'cid', 'title', 'mainPid']));
 	} else {
 		// mainPid ok to leave as-is
 		cid = -1;
@@ -236,9 +236,10 @@ Notes.assertTopic = async (uid, id) => {
 	}
 
 	tid = tid || utils.generateUUID();
+	mainPost.tid = tid;
 
 	const unprocessed = chain.filter((p, idx) => !members[idx]);
-	winston.info(`[notes/assertTopic] ${unprocessed.length} new note(s) found.`);
+	winston.verbose(`[notes/assertTopic] ${unprocessed.length} new note(s) found.`);
 
 	const [ids, timestamps] = [
 		unprocessed.map(n => (utils.isNumber(n.pid) ? parseInt(n.pid, 10) : n.pid)),
@@ -252,16 +253,24 @@ Notes.assertTopic = async (uid, id) => {
 		timestamps.splice(idx, 1);
 	}
 
-	await Promise.all([
-		!hasTid ? db.setObject(`topic:${tid}`, {
+	let tags;
+	if (!hasTid) {
+		tags = (mainPost._activitypub.tag || []).map(o => o.name.slice(1));
+		tags = await topics.filterTags(tags, cid);
+
+		await topics.create({
 			tid,
 			uid: authorId,
-			cid: cid,
+			cid,
 			mainPid,
 			title,
-			slug: `${tid}/${slugify(title)}`,
 			timestamp,
-		}) : null,
+			tags,
+		});
+		topics.onNewPostMade(mainPost);
+	}
+
+	await Promise.all([
 		db.sortedSetAdd(`tid:${tid}:posts`, timestamps, ids),
 		Notes.assert(uid, unprocessed),
 	]);
diff --git a/src/topics/create.js b/src/topics/create.js
index e292e4ba11..0dea1e3133 100644
--- a/src/topics/create.js
+++ b/src/topics/create.js
@@ -20,7 +20,7 @@ module.exports = function (Topics) {
 		// This is an internal method, consider using Topics.post instead
 		const timestamp = data.timestamp || Date.now();
 
-		const tid = await db.incrObjectField('global', 'nextTid');
+		const tid = data.tid || await db.incrObjectField('global', 'nextTid');
 
 		let topicData = {
 			tid: tid,