initializeApp static method

Future<FirebaseApp> initializeApp({
  1. String? name,
  2. FirebaseOptions? options,
  3. String? demoProjectId,

Initializes a new FirebaseApp instance by name and options and returns the created app. This method should be called before any usage of FlutterFire plugins.

The default app instance can be initialized here simply by passing no "name" as an argument in both Dart & manual initialization flows. If you have a google-services.json file in your android project or a GoogleService-Info.plist file in your iOS+ project, it will automatically create a default (named "DEFAULT") app instance on the native platform. However, you will still need to call this method before using any FlutterFire plugins.


static Future<FirebaseApp> initializeApp({
  String? name,
  FirebaseOptions? options,
  String? demoProjectId,
}) async {
  if (demoProjectId != null) {
    late final String platformString;
    if (defaultTargetPlatform == {
      platformString = 'android';
    } else if (defaultTargetPlatform == TargetPlatform.iOS ||
        defaultTargetPlatform == TargetPlatform.macOS) {
      platformString = 'ios';
    } else {
      // We use 'web' as the default platform for unknown platforms.
      platformString = 'web';
    FirebaseAppPlatform app = await _delegate.initializeApp(
      options: FirebaseOptions(
        apiKey: '',
        appId: '1:1:$platformString:1',
        messagingSenderId: '',
        projectId: demoProjectId,

    return FirebaseApp._(app);
  FirebaseAppPlatform app = await _delegate.initializeApp(
    name: name,
    options: options,

  return FirebaseApp._(app);