diff --git a/src/activitypub/index.js b/src/activitypub/index.js
index f21e7cf10c..57227a2e20 100644
--- a/src/activitypub/index.js
+++ b/src/activitypub/index.js
@@ -7,6 +7,7 @@ const { createHash, createSign, createVerify } = require('crypto');
 const request = require('../request');
 const db = require('../database');
 const user = require('../user');
+const utils = require('../utils');
 const ttl = require('../cache/ttl');
 
 const requestCache = ttl({ ttl: 1000 * 60 * 5 }); // 5 minutes
@@ -103,12 +104,18 @@ ActivityPub.fetchPublicKey = async (uri) => {
 };
 
 ActivityPub.sign = async (uid, url, payload) => {
+	// Sanity checking
+	if (!utils.isNumber(uid) || parseInt(uid, 10) < 0) {
+		throw new Error('[[error:invalid-uid]]');
+	}
+	uid = parseInt(uid, 10);
+
 	// Returns string for use in 'Signature' header
 	const { host, pathname } = new URL(url);
 	const date = new Date().toUTCString();
 	const key = await ActivityPub.getPrivateKey(uid);
 	const userslug = await user.getUserField(uid, 'userslug');
-	const keyId = `${nconf.get('url')}/user/${userslug}#key`;
+	const keyId = `${nconf.get('url')}${uid > 0 ? `/user/${userslug}` : ''}#key`;
 	let digest = null;
 
 	let headers = '(request-target) host date';
@@ -183,7 +190,7 @@ ActivityPub.get = async (uid, uri) => {
 		return requestCache.get(cacheKey);
 	}
 
-	const headers = uid > 0 ? await ActivityPub.sign(uid, uri) : {};
+	const headers = uid >= 0 ? await ActivityPub.sign(uid, uri) : {};
 	winston.verbose(`[activitypub/get] ${uri}`);
 	const { response, body } = await request.get(uri, {
 		headers: {
diff --git a/src/controllers/activitypub/actors.js b/src/controllers/activitypub/actors.js
new file mode 100644
index 0000000000..342b59c367
--- /dev/null
+++ b/src/controllers/activitypub/actors.js
@@ -0,0 +1,68 @@
+'use strict';
+
+const nconf = require('nconf');
+
+const user = require('../../user');
+const meta = require('../../meta');
+const activitypub = require('../../activitypub');
+
+const Actors = module.exports;
+
+Actors.application = async function (req, res) {
+	const publicKey = await activitypub.getPublicKey(0);
+	const name = meta.config.title || 'NodeBB';
+
+	res.status(200).json({
+		'@context': [
+			'https://www.w3.org/ns/activitystreams',
+			'https://w3id.org/security/v1',
+		],
+		id: `${nconf.get('url')}`,
+		url: `${nconf.get('url')}`,
+		inbox: `${nconf.get('url')}/inbox`,
+		outbox: `${nconf.get('url')}/outbox`,
+
+		type: 'Application',
+		name,
+
+		publicKey: {
+			id: `${nconf.get('url')}#key`,
+			owner: nconf.get('url'),
+			publicKeyPem: publicKey,
+		},
+	});
+};
+
+Actors.user = async function (req, res) {
+	// todo: view:users priv gate
+	const { userslug } = req.params;
+	const { uid } = res.locals;
+	const { username, displayname: name, aboutme, picture, 'cover:url': cover } = await user.getUserData(uid);
+	const publicKey = await activitypub.getPublicKey(uid);
+
+	res.status(200).json({
+		'@context': [
+			'https://www.w3.org/ns/activitystreams',
+			'https://w3id.org/security/v1',
+		],
+		id: `${nconf.get('url')}/user/${userslug}`,
+		url: `${nconf.get('url')}/user/${userslug}`,
+		followers: `${nconf.get('url')}/user/${userslug}/followers`,
+		following: `${nconf.get('url')}/user/${userslug}/following`,
+		inbox: `${nconf.get('url')}/user/${userslug}/inbox`,
+		outbox: `${nconf.get('url')}/user/${userslug}/outbox`,
+
+		type: 'Person',
+		name,
+		preferredUsername: username,
+		summary: aboutme,
+		icon: picture ? `${nconf.get('url')}${picture}` : null,
+		image: cover ? `${nconf.get('url')}${cover}` : null,
+
+		publicKey: {
+			id: `${nconf.get('url')}/user/${userslug}#key`,
+			owner: `${nconf.get('url')}/user/${userslug}`,
+			publicKeyPem: publicKey,
+		},
+	});
+};
diff --git a/src/controllers/activitypub/index.js b/src/controllers/activitypub/index.js
index 9c516f7d01..ae13e3e25e 100644
--- a/src/controllers/activitypub/index.js
+++ b/src/controllers/activitypub/index.js
@@ -9,43 +9,10 @@ const helpers = require('../helpers');
 
 const Controller = module.exports;
 
+Controller.actors = require('./actors');
 Controller.profiles = require('./profiles');
 Controller.topics = require('./topics');
 
-Controller.getActor = async (req, res) => {
-	// todo: view:users priv gate
-	const { userslug } = req.params;
-	const { uid } = res.locals;
-	const { username, displayname: name, aboutme, picture, 'cover:url': cover } = await user.getUserData(uid);
-	const publicKey = await activitypub.getPublicKey(uid);
-
-	res.status(200).json({
-		'@context': [
-			'https://www.w3.org/ns/activitystreams',
-			'https://w3id.org/security/v1',
-		],
-		id: `${nconf.get('url')}/user/${userslug}`,
-		url: `${nconf.get('url')}/user/${userslug}`,
-		followers: `${nconf.get('url')}/user/${userslug}/followers`,
-		following: `${nconf.get('url')}/user/${userslug}/following`,
-		inbox: `${nconf.get('url')}/user/${userslug}/inbox`,
-		outbox: `${nconf.get('url')}/user/${userslug}/outbox`,
-
-		type: 'Person',
-		name,
-		preferredUsername: username,
-		summary: aboutme,
-		icon: picture ? `${nconf.get('url')}${picture}` : null,
-		image: cover ? `${nconf.get('url')}${cover}` : null,
-
-		publicKey: {
-			id: `${nconf.get('url')}/user/${userslug}#key`,
-			owner: `${nconf.get('url')}/user/${userslug}`,
-			publicKeyPem: publicKey,
-		},
-	});
-};
-
 Controller.getFollowing = async (req, res) => {
 	const { followingCount: totalItems } = await user.getUserFields(res.locals.uid, ['followingCount']);
 
diff --git a/src/routes/activitypub.js b/src/routes/activitypub.js
index 8bd686308f..b96e57f83d 100644
--- a/src/routes/activitypub.js
+++ b/src/routes/activitypub.js
@@ -14,7 +14,8 @@ module.exports = function (app, middleware, controllers) {
 
 	const middlewares = [middleware.activitypub.enabled, middleware.activitypub.assertS2S, middleware.exposeUid];
 
-	app.get('/user/:userslug', middlewares, controllers.activitypub.getActor);
+	app.get('/', middlewares, controllers.activitypub.actors.application);
+	app.get('/user/:userslug', middlewares, controllers.activitypub.actors.user);
 
 	app.get('/user/:userslug/inbox', middlewares, controllers.activitypub.getInbox);
 	app.post('/user/:userslug/inbox', [...middlewares, middleware.activitypub.validate], controllers.activitypub.postInbox);
diff --git a/src/routes/index.js b/src/routes/index.js
index 451d68a9fe..ed9ad8eb5f 100644
--- a/src/routes/index.js
+++ b/src/routes/index.js
@@ -137,17 +137,17 @@ module.exports = async function (app, middleware) {
 
 	app.use(middleware.stripLeadingSlashes);
 
+	await plugins.reloadRoutes({ router: router });
+	await authRoutes.reloadRoutes({ router: router });
+	await writeRoutes.reload({ router: router });
+	addCoreRoutes(app, router, middleware, mounts);
+
 	// handle custom homepage routes
 	router.use('/', controllers.home.rewrite);
 
 	// homepage handled by `action:homepage.get:[route]`
 	setupPageRoute(router, '/', [], controllers.home.pluginHook);
 
-	await plugins.reloadRoutes({ router: router });
-	await authRoutes.reloadRoutes({ router: router });
-	await writeRoutes.reload({ router: router });
-	addCoreRoutes(app, router, middleware, mounts);
-
 	winston.info('[router] Routes added');
 };
 
diff --git a/test/activitypub.js b/test/activitypub.js
index 770a287c6a..da1a4b8992 100644
--- a/test/activitypub.js
+++ b/test/activitypub.js
@@ -174,7 +174,7 @@ describe('ActivityPub integration', () => {
 		});
 	});
 
-	describe('Actor endpoint', () => {
+	describe('User Actor endpoint', () => {
 		let uid;
 		let slug;
 
@@ -216,6 +216,43 @@ describe('ActivityPub integration', () => {
 		});
 	});
 
+	describe('Instance Actor endpoint', () => {
+		let response;
+		let body;
+
+		before(async () => {
+			({ response, body } = await request.get(nconf.get('url'), {
+				headers: {
+					Accept: 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
+				},
+			}));
+		});
+
+		it('should respond properly', async () => {
+			assert(response);
+			assert.strictEqual(response.statusCode, 200);
+		});
+
+		it('should return a valid ActivityPub Actor JSON-LD payload', async () => {
+			console.log(body);
+			assert(body.hasOwnProperty('@context'));
+			assert(body['@context'].includes('https://www.w3.org/ns/activitystreams'));
+
+			['id', 'url', 'inbox', 'outbox'].forEach((prop) => {
+				assert(body.hasOwnProperty(prop));
+				assert(body[prop]);
+			});
+
+			assert.strictEqual(body.id, body.url);
+			assert.strictEqual(body.type, 'Application');
+		});
+
+		it('should contain a `publicKey` property with a public key', async () => {
+			assert(body.hasOwnProperty('publicKey'));
+			assert(['id', 'owner', 'publicKeyPem'].every(prop => body.publicKey.hasOwnProperty(prop)));
+		});
+	});
+
 	describe('http signature signing and verification', () => {
 		describe('.sign()', () => {
 			let uid;
@@ -256,6 +293,33 @@ describe('ActivityPub integration', () => {
 				assert(digest);
 				assert.strictEqual(digest, `sha-256=${checksum}`);
 			});
+
+			it('should create a key for NodeBB itself if a uid of 0 is passed in', async () => {
+				const endpoint = `${nconf.get('url')}/user/${username}/inbox`;
+				await activitypub.sign(0, endpoint);
+				const { publicKey, privateKey } = await db.getObject(`uid:0:keys`);
+
+				assert(publicKey);
+				assert(privateKey);
+			});
+
+			it('should return headers with an appropriate key id uri', async () => {
+				const endpoint = `${nconf.get('url')}/user/${username}/inbox`;
+				const { signature } = await activitypub.sign(uid, endpoint);
+				const [keyId] = signature.split(',');
+
+				assert(signature);
+				assert.strictEqual(keyId, `keyId="${nconf.get('url')}/user/${username}#key"`);
+			});
+
+			it('should return the instance key id when uid is 0', async () => {
+				const endpoint = `${nconf.get('url')}/user/${username}/inbox`;
+				const { signature } = await activitypub.sign(0, endpoint);
+				const [keyId] = signature.split(',');
+
+				assert(signature);
+				assert.strictEqual(keyId, `keyId="${nconf.get('url')}#key"`);
+			});
 		});
 
 		describe('.verify()', () => {