diff --git a/common/user.ts b/common/user.ts
index f35cbdaf..0ba23010 100644
--- a/common/user.ts
+++ b/common/user.ts
@@ -1,12 +1,14 @@
 export type User = {
   id: string
-  email: string
+  createdTime: number
+
   name: string
   username: string
-  avatarUrl: string
+  avatarUrl?: string
+
   balance: number
-  createdTime: number
-  lastUpdatedTime: number
   totalPnLCached: number
   creatorVolumeCached: number
 }
+
+export const STARTING_BALANCE = 1000
diff --git a/common/util/random.ts b/common/util/random.ts
index 59ab5ba9..ce2bc54a 100644
--- a/common/util/random.ts
+++ b/common/util/random.ts
@@ -1,4 +1,7 @@
-export const randomString = () => Math.random().toString(16).substr(2, 14)
+export const randomString = (length = 12) =>
+  Math.random()
+    .toString(16)
+    .substring(2, length + 2)
 
 export function createRNG(seed: string) {
   // https://stackoverflow.com/a/47593316/1592933
diff --git a/functions/src/create-user.ts b/functions/src/create-user.ts
new file mode 100644
index 00000000..55fac600
--- /dev/null
+++ b/functions/src/create-user.ts
@@ -0,0 +1,54 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+
+import { STARTING_BALANCE, User } from '../../common/user'
+import { getUser, getUserByUsername } from './utils'
+import { slugify } from '../../common/util/slugify'
+import { randomString } from '../../common/util/random'
+
+export const createUser = functions
+  .runWith({ minInstances: 1 })
+  .https.onCall(async (_, context) => {
+    const userId = context?.auth?.uid
+    if (!userId) return { status: 'error', message: 'Not authorized' }
+
+    const preexistingUser = await getUser(userId)
+    if (preexistingUser)
+      return { status: 'error', message: 'User already created' }
+
+    const fbUser = await admin.auth().getUser(userId)
+
+    const email = fbUser.email
+    const emailName = email?.replace(/@.*$/, '')
+
+    const name = fbUser.displayName || emailName || 'User' + randomString(4)
+    let username = cleanUsername(name)
+
+    const sameNameUser = await getUserByUsername(username)
+    if (sameNameUser) {
+      username += randomString(4)
+    }
+
+    const avatarUrl = fbUser.photoURL
+
+    const user: User = {
+      id: userId,
+      name,
+      username,
+      avatarUrl,
+      balance: STARTING_BALANCE,
+      createdTime: Date.now(),
+    }
+
+    await firestore.collection('users').doc(userId).create(user)
+
+    console.log('created user', username, 'firebase id:', userId)
+
+    return { status: 'success', user }
+  })
+
+const cleanUsername = (name: string) => {
+  return slugify(name.replace(/\s+/g, ''))
+}
+
+const firestore = admin.firestore()
diff --git a/functions/src/index.ts b/functions/src/index.ts
index bc769ea2..534e72cf 100644
--- a/functions/src/index.ts
+++ b/functions/src/index.ts
@@ -9,5 +9,6 @@ export * from './resolve-market'
 export * from './stripe'
 export * from './sell-bet'
 export * from './create-contract'
+export * from './create-user'
 export * from './update-contract-metrics'
 export * from './update-user-metrics'
diff --git a/functions/src/utils.ts b/functions/src/utils.ts
index 887d602c..e6ecd7cf 100644
--- a/functions/src/utils.ts
+++ b/functions/src/utils.ts
@@ -22,6 +22,15 @@ export const getUser = (userId: string) => {
   return getValue<User>('users', userId)
 }
 
+export const getUserByUsername = async (username: string) => {
+  const snap = await firestore
+    .collection('users')
+    .where('username', '==', username)
+    .get()
+
+  return snap.empty ? undefined : (snap.docs[0].data() as User)
+}
+
 const firestore = admin.firestore()
 
 const updateUserBalance = (userId: string, delta: number) => {
diff --git a/web/lib/firebase/api-call.ts b/web/lib/firebase/api-call.ts
index 3d541291..4871259b 100644
--- a/web/lib/firebase/api-call.ts
+++ b/web/lib/firebase/api-call.ts
@@ -1,4 +1,5 @@
 import { getFunctions, httpsCallable } from 'firebase/functions'
+import { User } from '../../../common/user'
 
 const functions = getFunctions()
 
@@ -11,3 +12,8 @@ export const placeBet = cloudFunction('placeBet')
 export const resolveMarket = cloudFunction('resolveMarket')
 
 export const sellBet = cloudFunction('sellBet')
+
+export const createUser = () =>
+  cloudFunction('createUser')({}).then(
+    (r) => (r.data as any)?.user as User | undefined
+  )
diff --git a/web/lib/firebase/users.ts b/web/lib/firebase/users.ts
index e4a07406..109359fc 100644
--- a/web/lib/firebase/users.ts
+++ b/web/lib/firebase/users.ts
@@ -21,10 +21,9 @@ import {
 
 import { User } from '../../../common/user'
 import { listenForValues } from './utils'
+import { createUser } from './api-call'
 export type { User }
 
-export const STARTING_BALANCE = 1000
-
 const db = getFirestore(app)
 export const auth = getAuth(app)
 
@@ -54,31 +53,22 @@ export function listenForUser(userId: string, setUser: (user: User) => void) {
 }
 
 const CACHED_USER_KEY = 'CACHED_USER_KEY'
+
 export function listenForLogin(onUser: (user: User | null) => void) {
   const cachedUser = localStorage.getItem(CACHED_USER_KEY)
   onUser(cachedUser ? JSON.parse(cachedUser) : null)
 
+  if (!cachedUser) createUser().catch(() => {}) // warm up cloud function
+
   return onAuthStateChanged(auth, async (fbUser) => {
     if (fbUser) {
-      let user = await getUser(fbUser.uid)
+      let user: User | null = await getUser(fbUser.uid)
+
       if (!user) {
         // User just created an account; save them to our database.
-        user = {
-          id: fbUser.uid,
-          name: fbUser.displayName || 'Default Name',
-          username:
-            fbUser.displayName?.replace(/\s+/g, '') || 'DefaultUsername',
-          avatarUrl: fbUser.photoURL || '',
-          email: fbUser.email || 'default@blah.com',
-          balance: STARTING_BALANCE,
-          // TODO: use Firestore timestamp?
-          createdTime: Date.now(),
-          lastUpdatedTime: Date.now(),
-          totalPnLCached: 0,
-          creatorVolumeCached: 0,
-        }
-        await setUser(fbUser.uid, user)
+        user = (await createUser()) || null
       }
+
       onUser(user)
 
       // Persist to local storage, to reduce login blink next time.