Expo Unimodule for interfacing with Firebase Authentication

Usage no npm install needed!

<script type="module">
  import expoFirebaseAuth from 'https://cdn.skypack.dev/expo-firebase-auth';



expo-firebase is still in RC and therefore subject to breaking changings. Be sure to run yarn upgrade and cd ios; pod install when upgrading.

expo-firebase-auth provides a comprehensive set of tools for authenticating users.

Full documentation


Now, you need to install the package from npm registry.

npm install expo-firebase-auth or yarn add expo-firebase-auth



If you're using Cocoapods, add the dependency to your Podfile:

pod 'EXFirebaseAuth', path: '../node_modules/expo-firebase-auth/ios'

and run pod install.


  1. Append the following lines to android/settings.gradle:

    include ':expo-firebase-auth'
    project(':expo-firebase-auth').projectDir = new File(rootProject.projectDir, '../node_modules/expo-firebase-auth/android')

    and if not already included

    include ':expo-core'
    project(':expo-core').projectDir = new File(rootProject.projectDir, '../node_modules/expo-core/android')
    include ':expo-firebase-app'
    project(':expo-firebase-app').projectDir = new File(rootProject.projectDir, '../node_modules/expo-firebase-app/android')
  2. Insert the following lines inside the dependencies block in android/app/build.gradle:

    api project(':expo-firebase-auth')

    and if not already included

    api project(':expo-core')
    api project(':expo-firebase-app')
  3. Include the module in your expo packages: ./android/app/src/main/java/host/exp/exponent/MainActivity.java

    * At the top of the file.
    * This is automatically imported with Android Studio, but if you are in any other editor you will need to manually import the module.
    import expo.modules.firebase.app.FirebaseAppPackage; // This should be here for all Expo Firebase features.
    import expo.modules.firebase.auth.FirebaseAuthPackage;
    // Later in the file...
    public List<Package> expoPackages() {
      // Here you can add your own packages.
      return Arrays.<Package>asList(
        new FirebaseAppPackage(), // This should be here for all Expo Firebase features.
        new FirebaseAuthPackage() // Include this.


import React from 'react';
import { Text, View } from 'react-native';
import firebase from 'expo-firebase-app';
import { Facebook } from 'expo';

// API can be accessed with: firebase.auth();

// IMPORTANT: Remember to enable the facebook auth in the firebase console!

export default class DemoView extends React.Component {
  state = { user: null };

  componentDidMount() {
    // List to the authentication state
    this._unsubscribe = firebase.auth().onAuthStateChanged(this.onAuthStateChanged);

  componentWillUnmount() {
    // Clean up: remove the listener

  onAuthStateChanged = user => {
    // if the user logs in or out, this will be called and the state will update.
    // This value can also be accessed via: firebase.auth().currentUser
    this.setState({ user });

  async facebookLogin() {
    // Get an API Key from https://developers.facebook.com/ (it's pretty easy)
    const authData = await Facebook.logInWithReadPermissionsAsync(FacebookApiKey);
    if (!authData) return;
    const { type, token } = authData;
    if (type === 'success') {
      return token;
    } else {
      // Maybe the user cancelled...

  loginAsync = async () => {
    // First we login to facebook and get an "Auth Token" then we use that token to create an account or login. This concept can be applied to github, twitter, google, ect...
    const token = await this.facebookLogin();
    if (!token) return;
    // Use the facebook token to authenticate our user in firebase.
    const credential = firebase.auth.FacebookAuthProvider.credential(token);
    try {
      // login with credential
      await firebase.auth().signInAndRetrieveDataWithCredential(credential);
    } catch ({ message }) {

  async logoutAsync() {
    try {
      await firebase.auth().signOut();
    } catch ({ message }) {

  toggleAuth = () => {
    if (!!this.state.user) {
    } else {

  render() {
    const { user } = this.state;
    const message = !!user ? 'Logout' : 'Login';
    return (
      <View style={{ flex: 1 }}>
        <Text onPress={this.toggleAuth}>{message}</Text>

Trouble Shooting

If your app crashes instantly on Android in a detached project: java.lang.RuntimeException: Unable to get provider com.google.firebase.provider.FirebaseInitProvider: java.lang.IllegalArgumentException: Given String is empty or null Check to make sure your native android/app/google-services.json has a "current_key": "YOUR_KEY" and not a blank string.