A Flutter plugin to use the Firebase Authentication API.

For Flutter plugins for other Firebase products, see FlutterFire.md.

Note: This plugin is still under development, and some APIs might not be available yet. Feedback and Pull Requests are most welcome!

The Google Sign-in plugin is required to use the firebase_auth plugin. Follow the Google sign-in plugin installation instructions.

To use the firebase_auth plugin, follow the plugin installation instructions.

Enable the Google services by configuring the Gradle scripts as such.

1. Add the classpath to the [project]/android/build.gradle file.

dependencies {
  // Example existing classpath
  classpath 'com.android.tools.build:gradle:3.0.1'
  // Add the google services classpath
  classpath 'com.google.gms:google-services:3.1.2'
}

2. Add the apply plugin to the [project]/android/app/build.gradle file.

// ADD THIS AT THE BOTTOM
apply plugin: 'com.google.gms.google-services'

Note: If this section is not completed you will get an error like this:

java.lang.IllegalStateException:
Default FirebaseApp is not initialized in this process [package name].
Make sure to call FirebaseApp.initializeApp(Context) first.

Note: When you are debugging on android, use a device or AVD with Google Play services. Otherwise you will not be able to authenticate.

Add the following imports to your Dart code:

import 'package:firebase_auth/firebase_auth.dart';

Initialize FirebaseAuth:

final FirebaseAuth _auth = FirebaseAuth.instance;

You can now use the Firebase _auth to authenticate in your Dart code, e.g.

Future<FirebaseUser> _handleSignIn() async {
  GoogleSignInAccount googleUser = await _googleSignIn.signIn();
  GoogleSignInAuthentication googleAuth = await googleUser.authentication;
  FirebaseUser user = await _auth.signInWithGoogle(
    accessToken: googleAuth.accessToken,
    idToken: googleAuth.idToken,
  );
  print("signed in " + user.displayName);
  return user;
}

Then from the sign in button onPress, call the _handleSignIn method using a future callback for both the FirebaseUser and possible exception.

_handleSignIn()
    .then((FirebaseUser user) => print(user))
    .catchError((e) => print(e));

See the example application source for a complete sample app using the Firebase authentication.

Please file issues to send feedback or report a bug. Thank you!