How to Store Additional User Data in Firebase Auth

1import { getFirestore, doc, setDoc, serverTimestamp } from 'firebase/firestore';
2import { getAuth, createUserWithEmailAndPassword } from 'firebase/auth';
3
4const db = getFirestore();
5const auth = getAuth();
6
7async function signUpAndCreateProfile(
8  email: string,
9  password: string,
10  displayName: string
11) {
12  // 1. Create the Firebase Auth account
13  const { user } = await createUserWithEmailAndPassword(auth, email, password);
14
15  // 2. Create a Firestore profile document with the same UID
16  await setDoc(doc(db, 'users', user.uid), {
17    email: user.email,
18    displayName: displayName,
19    photoURL: null,
20    role: 'member',
21    bio: '',
22    createdAt: serverTimestamp(),
23    updatedAt: serverTimestamp()
24  });
25
26  return user;
27}

1rules_version = '2';
2service cloud.firestore {
3  match /databases/{database}/documents {
4    match /users/{userId} {
5      // Users can read their own profile
6      allow read: if request.auth != null && request.auth.uid == userId;
7
8      // Users can create their own profile during sign-up
9      allow create: if request.auth != null
10        && request.auth.uid == userId
11        && request.resource.data.keys().hasAll(['email', 'displayName', 'role'])
12        && request.resource.data.role == 'member';
13
14      // Users can update their own profile (but not role or createdAt)
15      allow update: if request.auth != null
16        && request.auth.uid == userId
17        && !request.resource.data.diff(resource.data).affectedKeys().hasAny(['role', 'createdAt']);
18    }
19  }
20}

1import { getAuth, onAuthStateChanged, User } from 'firebase/auth';
2import { getFirestore, doc, getDoc } from 'firebase/firestore';
3
4interface UserProfile {
5  email: string;
6  displayName: string;
7  photoURL: string | null;
8  role: string;
9  bio: string;
10}
11
12const auth = getAuth();
13const db = getFirestore();
14
15onAuthStateChanged(auth, async (user: User | null) => {
16  if (user) {
17    // Fetch the Firestore profile
18    const profileDoc = await getDoc(doc(db, 'users', user.uid));
19
20    if (profileDoc.exists()) {
21      const profile = profileDoc.data() as UserProfile;
22      console.log('User profile:', profile);
23      // Set your app state with the combined user + profile data
24    } else {
25      console.warn('No profile found for user:', user.uid);
26    }
27  } else {
28    // User is signed out — clear profile state
29    console.log('No user signed in');
30  }
31});

1import { getFirestore, doc, updateDoc, serverTimestamp } from 'firebase/firestore';
2import { getAuth } from 'firebase/auth';
3
4const db = getFirestore();
5const auth = getAuth();
6
7async function updateProfile(updates: {
8  displayName?: string;
9  bio?: string;
10  photoURL?: string | null;
11}) {
12  const user = auth.currentUser;
13  if (!user) throw new Error('Not authenticated');
14
15  await updateDoc(doc(db, 'users', user.uid), {
16    ...updates,
17    updatedAt: serverTimestamp()
18  });
19
20  console.log('Profile updated successfully');
21}

1// Cloud Function to set custom claims (server-side)
2// functions/src/index.ts
3import { onCall, HttpsError } from 'firebase-functions/v2/https';
4import { getAuth } from 'firebase-admin/auth';
5import { initializeApp } from 'firebase-admin/app';
6
7initializeApp();
8
9export const setUserRole = onCall(async (request) => {
10  // Only admins can set roles
11  if (request.auth?.token?.role !== 'admin') {
12    throw new HttpsError('permission-denied', 'Only admins can set roles');
13  }
14
15  const { uid, role } = request.data;
16  if (!uid || !role) {
17    throw new HttpsError('invalid-argument', 'uid and role required');
18  }
19
20  await getAuth().setCustomUserClaims(uid, { role });
21  return { success: true };
22});