A Flutter plugin for Google Sign In.

Platform integration

Android integration

To access Google Sign-In, you'll need to make sure to register your application.

You don‘t need to include the google-services.json file in your app unless you are using Google services that require it. You do need to enable the OAuth APIs that you want, using the Google Cloud Platform API manager. For example, if you want to mimic the behavior of the Google Sign-In sample app, you’ll need to enable the Google People API.

Make sure you've filled out all required fields in the console for OAuth consent screen. Otherwise, you may encounter APIException errors.

iOS integration

1. First register your application.
2. Make sure the file you download in step 1 is named GoogleService-Info.plist.
3. Move or copy GoogleService-Info.plist into the [my_project]/ios/Runner directory.
4. Open Xcode, then right-click on Runner directory and select Add Files to "Runner".
5. Select GoogleService-Info.plist from the file manager.
6. A dialog will show up and ask you to select the targets, select the Runner target.
7. If you need to authenticate to a backend server you can add a SERVER_CLIENT_ID key value pair in your GoogleService-Info.plist.

   <key>SERVER_CLIENT_ID</key>
   <string>[YOUR SERVER CLIENT ID]</string>
   

8. Then add the CFBundleURLTypes attributes below into the [my_project]/ios/Runner/Info.plist file.

<!-- Put me in the [my_project]/ios/Runner/Info.plist file -->
<!-- Google Sign-in Section -->
<key>CFBundleURLTypes</key>
<array>
	<dict>
		<key>CFBundleTypeRole</key>
		<string>Editor</string>
		<key>CFBundleURLSchemes</key>
		<array>
			<!-- TODO Replace this value: -->
			<!-- Copied from GoogleService-Info.plist key REVERSED_CLIENT_ID -->
			<string>com.googleusercontent.apps.861823949799-vc35cprkp249096uujjn0vvnmcvjppkn</string>
		</array>
	</dict>
</array>
<!-- End of the Google Sign-in Section -->

As an alternative to adding GoogleService-Info.plist to your Xcode project, you can instead configure your app in Dart code. In this case, skip steps 3 to 7 and pass clientId and serverClientId to the GoogleSignIn constructor:

GoogleSignIn _googleSignIn = GoogleSignIn(
  ...
  // The OAuth client id of your app. This is required.
  clientId: ...,
  // If you need to authenticate to a backend server, specify its OAuth client. This is optional.
  serverClientId: ...,
);

Note that step 8 is still required.

iOS additional requirement

Note that according to https://developer.apple.com/sign-in-with-apple/get-started, starting June 30, 2020, apps that use login services must also offer a “Sign in with Apple” option when submitting to the Apple App Store.

Consider also using an Apple sign in plugin from pub.dev.

The Flutter Favorite sign_in_with_apple plugin could be an option.

Web integration

For web integration details, see the google_sign_in_web package.

Usage

Import the package

To use this plugin, follow the plugin installation instructions.

Use the plugin

Add the following import to your Dart code:

import 'package:google_sign_in/google_sign_in.dart';

Initialize GoogleSignIn with the scopes you want:

GoogleSignIn _googleSignIn = GoogleSignIn(
  scopes: [
    'email',
    'https://www.googleapis.com/auth/contacts.readonly',
  ],
);

Full list of available scopes.

You can now use the GoogleSignIn class to authenticate in your Dart code, e.g.

Future<void> _handleSignIn() async {
  try {
    await _googleSignIn.signIn();
  } catch (error) {
    print(error);
  }
}

Example

Find the example wiring in the Google sign-in example application.