How to Fix Firebase Auth Session Persistence Issues

1import { getAuth, setPersistence, browserLocalPersistence, browserSessionPersistence, inMemoryPersistence } from 'firebase/auth';
2
3const auth = getAuth();
4
5// Default — survives browser close
6await setPersistence(auth, browserLocalPersistence);
7
8// Session only — clears when tab closes
9await setPersistence(auth, browserSessionPersistence);
10
11// In-memory only — clears on page refresh
12await setPersistence(auth, inMemoryPersistence);

1import { getAuth, onAuthStateChanged } from 'firebase/auth';
2
3const auth = getAuth();
4
5// WRONG: May be null during session restoration
6console.log(auth.currentUser); // null!
7
8// CORRECT: Wait for auth state to be determined
9onAuthStateChanged(auth, (user) => {
10  if (user) {
11    console.log('Session restored:', user.uid);
12    // Render authenticated UI
13  } else {
14    console.log('No session found');
15    // Redirect to login
16  }
17});

1import { getAuth, onAuthStateChanged, User } from 'firebase/auth';
2import { useEffect, useState } from 'react';
3
4// This hook safely handles SSR — only runs auth logic in the browser
5export function useFirebaseAuth() {
6  const [user, setUser] = useState<User | null>(null);
7  const [loading, setLoading] = useState(true);
8
9  useEffect(() => {
10    // useEffect only runs in the browser, never on the server
11    const auth = getAuth();
12    const unsubscribe = onAuthStateChanged(auth, (firebaseUser) => {
13      setUser(firebaseUser);
14      setLoading(false);
15    });
16    return unsubscribe;
17  }, []);
18
19  return { user, loading };
20}

1import { getAuth, setPersistence, browserLocalPersistence, inMemoryPersistence, signInWithEmailAndPassword } from 'firebase/auth';
2
3const auth = getAuth();
4
5async function signIn(email: string, password: string) {
6  try {
7    // Try local persistence first
8    await setPersistence(auth, browserLocalPersistence);
9  } catch (error) {
10    // IndexedDB blocked (private browsing) — fall back
11    console.warn('Local persistence unavailable, using in-memory');
12    await setPersistence(auth, inMemoryPersistence);
13  }
14
15  return signInWithEmailAndPassword(auth, email, password);
16}

1// Diagnostic: check what persistence mode is active
2import { getAuth } from 'firebase/auth';
3
4const auth = getAuth();
5
6// Log the current auth state for debugging
7console.log('Auth config:', {
8  currentUser: auth.currentUser?.uid || 'null',
9  tenantId: auth.tenantId,
10  name: auth.name
11});
12
13// After sign-in, verify the session is persisted
14onAuthStateChanged(auth, (user) => {
15  if (user) {
16    console.log('Session persisted. UID:', user.uid);
17    console.log('Token expiry:', user.metadata.lastSignInTime);
18  }
19});