diff --git a/backend/src/activitypub/actors/index.ts b/backend/src/activitypub/actors/index.ts
index 08d311b..2ec74ef 100644
--- a/backend/src/activitypub/actors/index.ts
+++ b/backend/src/activitypub/actors/index.ts
@@ -34,6 +34,8 @@ export interface Actor extends APObject {
 	following: URL
 	followers: URL
 
+	alsoKnownAs?: string
+
 	[emailSymbol]: string
 }
 
@@ -200,6 +202,16 @@ export async function updateActorProperty(db: D1Database, actorId: URL, key: str
 	}
 }
 
+export async function setActorAlias(db: D1Database, actorId: URL, alias: URL) {
+	const { success, error } = await db
+		.prepare(`UPDATE actors SET properties=json_set(properties, '$.alsoKnownAs', json_array(?)) WHERE id=?`)
+		.bind(alias.toString(), actorId.toString())
+		.run()
+	if (!success) {
+		throw new Error('SQL error: ' + error)
+	}
+}
+
 export async function getActorById(db: D1Database, id: URL): Promise<Actor | null> {
 	const stmt = db.prepare('SELECT * FROM actors WHERE id=?').bind(id.toString())
 	const { results } = await stmt.all()
diff --git a/backend/test/wildebeest/settings.spec.ts b/backend/test/wildebeest/settings.spec.ts
new file mode 100644
index 0000000..3dc923a
--- /dev/null
+++ b/backend/test/wildebeest/settings.spec.ts
@@ -0,0 +1,58 @@
+import { makeDB } from '../utils'
+import { strict as assert } from 'node:assert/strict'
+import { createPerson, getActorById } from 'wildebeest/backend/src/activitypub/actors'
+import * as account_alias from 'wildebeest/functions/api/wb/settings/account/alias'
+
+const domain = 'cloudflare.com'
+const userKEK = 'test_kek22'
+
+describe('Wildebeest', () => {
+	describe('Settings', () => {
+		test('add account alias', async () => {
+			const db = await makeDB()
+			const actor = await createPerson(domain, db, userKEK, 'sven@cloudflare.com')
+
+			globalThis.fetch = async (input: RequestInfo) => {
+				if (input.toString() === 'https://example.com/.well-known/webfinger?resource=acct%3Atest%40example.com') {
+					return new Response(
+						JSON.stringify({
+							links: [
+								{
+									rel: 'self',
+									type: 'application/activity+json',
+									href: 'https://social.com/someone',
+								},
+							],
+						})
+					)
+				}
+
+				if (input.toString() === 'https://social.com/someone') {
+					return new Response(
+						JSON.stringify({
+							id: 'https://social.com/someone',
+						})
+					)
+				}
+
+				throw new Error('unexpected request to ' + input)
+			}
+
+			const alias = 'test@example.com'
+
+			const req = new Request('https://example.com', {
+				method: 'POST',
+				body: JSON.stringify({ alias }),
+			})
+			const res = await account_alias.handleRequestPost(db, req, actor)
+			assert.equal(res.status, 201)
+
+			// Ensure the actor has the alias set
+			const newActor = await getActorById(db, actor.id)
+			assert(newActor)
+			assert(newActor.alsoKnownAs)
+			assert.equal(newActor.alsoKnownAs.length, 1)
+			assert.equal(newActor.alsoKnownAs[0], 'https://social.com/someone')
+		})
+	})
+})
diff --git a/functions/ap/users/[id].ts b/functions/ap/users/[id].ts
index 9aa4ed5..7eaf06f 100644
--- a/functions/ap/users/[id].ts
+++ b/functions/ap/users/[id].ts
@@ -35,6 +35,10 @@ export async function handleRequest(domain: string, db: D1Database, id: string):
 			{
 				toot: 'http://joinmastodon.org/ns#',
 				discoverable: 'toot:discoverable',
+				alsoKnownAs: {
+					'@id': 'as:alsoKnownAs',
+					'@type': '@id',
+				},
 			},
 		],
 
diff --git a/functions/api/wb/settings/account/alias.ts b/functions/api/wb/settings/account/alias.ts
new file mode 100644
index 0000000..8edbb2e
--- /dev/null
+++ b/functions/api/wb/settings/account/alias.ts
@@ -0,0 +1,34 @@
+import type { Env } from 'wildebeest/backend/src/types/env'
+import { setActorAlias } from 'wildebeest/backend/src/activitypub/actors'
+import type { ContextData } from 'wildebeest/backend/src/types/context'
+import type { Actor } from 'wildebeest/backend/src/activitypub/actors'
+import { parseHandle } from 'wildebeest/backend/src/utils/parse'
+import { queryAcct } from 'wildebeest/backend/src/webfinger'
+import * as errors from 'wildebeest/backend/src/errors'
+
+export const onRequestPost: PagesFunction<Env, any, ContextData> = async ({ env, request, data }) => {
+	return handleRequestPost(env.DATABASE, request, data.connectedActor)
+}
+
+type AddAliasRequest = {
+	alias: string
+}
+
+export async function handleRequestPost(db: D1Database, request: Request, connectedActor: Actor): Promise<Response> {
+	const body = await request.json<AddAliasRequest>()
+
+	const handle = parseHandle(body.alias)
+	const acct = `${handle.localPart}@${handle.domain}`
+	if (handle.domain === null) {
+		console.warn("account migration within an instance isn't supported")
+		return new Response('', { status: 400 })
+	}
+	const actor = await queryAcct(handle.domain, acct)
+	if (actor === null) {
+		return errors.resourceNotFound('actor', acct)
+	}
+
+	await setActorAlias(db, connectedActor.id, actor.id)
+
+	return new Response('', { status: 201 })
+}