Platform authentication for Android games

In order to access Google Play Games Services functionality, your game needs to provide the authenticated player's account. This documentation describes how to implement a seamless authentication experience in your game.

The Play Games Services v2 SDK brings a number of improvements that increase the number of users authenticated into your game, and make development easier:

Improvements for users:
- After selecting a default account, users are authenticated without needing to interact with a prompt.
- Users no longer need to download the Play Games App to authenticate with Play Games Services or create a new account.
- Users can now manage their Play Games Services accounts for multiple games from a single page.
Improvements for developers:
Client code no longer needs to handle the authentication or sign-out flow, as login is automatically triggered when the game starts, and account management is handled in the OS settings.

New client integration

This section shows how to do a new client integration with Play Games Services Sign In v2.

Add the dependency

Add the Play Game Services SDK dependency to your app's root-level build.gradle file. If you are using Gradle, you can add or update the dependency as follows:

dependencies {
 implementation "com.google.android.gms:play-services-games-v2:+"
}

Define the project ID

To add the Play Games Services SDK project ID to your app, complete the following steps:

In your app's AndroidManifest.xml file, add the following <meta-data> element and attributes to the <application> element:
```
<manifest>
  <application>
    <meta-data android:name="com.google.android.gms.games.APP_ID"
               android:value="@string/game_services_project_id"/>
  </application>
</manifest>
```
Define the String resource reference @string/game_services_project_id using your games' Game services project id as the value. Your Games services project id can be found under your game name in the Configuration page on the Google Play Console.

In your res/values/strings.xml file, add a string resource reference and set your project ID as the value. In Google Play Console, you can find your project ID under your game name in the Configuration page. For example:

<!-- res/values/strings.xml -->
<resources>
  <!-- Replace 0000000000 with your game's project id. Example value shown above.  -->
  <string translatable="false"  name="game_services_project_id"> 0000000000 </string>
</resources>

Initialize the SDK

Initialize Play Games SDK in the onCreate(..) callback of your Application class.

import com.google.android.gms.games.PlayGamesSdk;

...

@Override
public void onCreate(){
  super.onCreate();
  PlayGamesSdk.initialize(this);
}

Get the authentication result

When your game launches, it will always attempt to authenticate the user. To authenticate the user, you must verify that the user successfully authenticated, and then get their Player ID.

To verify the authentication attempt, call GamesSignInClient.isAuthenticated() and use addOnCompleteListener to retrieve the results. For example:

GamesSignInClient gamesSignInClient = PlayGames.getGamesSignInClient(getActivity());

gamesSignInClient.isAuthenticated().addOnCompleteListener(isAuthenticatedTask -> {
  boolean isAuthenticated =
    (isAuthenticatedTask.isSuccessful() &&
     isAuthenticatedTask.getResult().isAuthenticated());

  if (isAuthenticated) {
    // Continue with Play Games Services
  } else {
    // Show a sign-in button to ask players to authenticate. Clicking it should
    // call GamesSignInClient.signIn().
  }
});

Prevent auto-triggered profile creation

You can disable auto-triggered profile creation prompts through the manifest file. This allows users without a Play Games Services profile to continue to load the game without being prompted to create a Play Games Services profile. For more information, see Profile creation options.

To use this feature, ensure that the following conditions are met:

No Play Games Services profile exists on any of the Google Accounts signed in on the device.
Your game is integrated with the Play Games Services SDK com.google.android.gms:play-services-games-v2:21.0.0 or higher.

To prevent the automatically triggered profile creation prompts, complete the following steps:

In the AndroidManifest.xml file, add the com.google.android.gms.games.SUPPRESS_GAME_PROFILE_CREATION tag in the <meta-data> element and attributes to the <application> element:
```
<application>
    ...
    <meta-data
        android:name="com.google.android.gms.games.SUPPRESS_GAME_PROFILE_CREATION"
        android:value="true" />
    ...
</application>
```
Setting this flag to true informs Play Games Services that your game will handle the profile creation process. Consequently, the Play Games Services won't automatically display the profile creation user interface for users on the device who don't have an existing Play Games Services profile.

When you call any Play Games Services API, the GamesClientStatusCodes.SIGN_IN_REQUIRED status code indicates that the call failed because the user couldn't be automatically authenticated due to the absence of a Play Games Services profile.

This allows users without a Play Games Services profile to proceed with your implemented authentication methods without immediately being prompted to create a Play Games Services profile. Profile creation can be initiated by calling GamesSignInService.signin().

import com.google.android.gms.games.PlayGames;
...

// Get the achievements client using Play Games services.
AchievementsClient achievementsClient = PlayGames.getAchievementsClient(getActivity());
achievementsClient.getAchievementsIntent()
    .addOnFailureListener(
        new OnFailureListener() {
          @Override
          public void onFailure(@NonNull Exception exception) {
            int statusCode = ((ApiException) exception).getStatusCode();
            if (statusCode == GamesClientStatusCodes.SIGN_IN_REQUIRED) {
              // SIGN_IN_REQUIRED: The user needs to sign in with Play Games Services.
              // Call GamesSignInService.signin() to prompt for
              // authentication at a suitable time which will trigger the
              // profile creation UI.
              // (e.g., after a tutorial). Use GamesSignInService.isAuthenticated() to check auth status.
            }
          }
        });

After you add the suppression tag, use the logcat window to verify the addition. The logcat output contains a message similar to the following: "Game opted out of automatic profile creation prompt (using manifest)".