Authenticate with Firebase Anonymously using Unity

You can use Firebase Authentication to create and use temporary anonymous accounts to authenticate with Firebase. These temporary anonymous accounts can be used to allow users who haven't yet signed up to your app to work with data protected by security rules. If an anonymous user decides to sign up to your app, you can link their sign-in credentials to the anonymous account so that they can continue to work with their protected data in future sessions.

Before you begin

    Before you can use the Firebase Authentication, you will need to create a Firebase project, and add the Firebase Unity SDK packages to your Unity project.

    Setup:

    Prerequisites

    Android

    iOS

    • Unity 5.0 or later
    • Xcode 7.0 or later

    If you don't have a Unity project already, you can download one of our quickstart samples and experiment with a specific Firebase feature. If you're using a quickstart, remember to get the bundle identifier from the project settings; you need it for the next step.

    Set up your app in the Firebase console

    To add Firebase to your app, you need a Firebase project and a Firebase configuration file for your app.

    Create a Firebase project in the Firebase console if you don't already have one. If you already have an existing Google project associated with your mobile app, click Import Google Project. Otherwise, click Add project.

    Android

    1. Click Add Firebase to your Android app and follow the setup steps. If you're importing an existing Google project, this may happen automatically and you can just download the config file.
    2. When prompted, enter your app's package name. It's important to enter the package name your app is using; this can only be set when you add an app to your Firebase project.
    3. Download a google-services.json file when instructed. You can redownload this file again at any time.
    4. Copy this file to anywhere inside your project's assets folder.

    IOs

    1. Click Add Firebase to your iOS app and follow the setup steps. If you're importing an existing Google project, this may happen automatically and you can just download the config file.
    2. When prompted, enter your app's bundle ID. It's important to enter the bundle ID your app is using; this can only be set when you add an app to your Firebase project.
    3. Download a GoogleService-Info.plist file when instructed. You can redownload this file again at any time.
    4. Add the GoogleService-Info.plist file to the project.

    5. Drag the GoogleService-Info.plist downloaded from the Firebase console into any folder in the Unity project.

    Add the Firebase Unity SDK to your app

    1. Download the Firebase Unity SDK.
    2. Select the Assets > Import Package > Custom Package menu item.
    3. Import the FirebaseAuth.unitypackage package from the Firebase Unity SDK, downloaded previously.
    4. When the Import Unity Package window appears, click the Import button.

    Build your app

    Android

    1. Select the File > Build Settings menu option.
    2. Select Android in the Platform list.
    3. Click Switch Platform to select Android as the target platform.
    4. Wait for the spinner (compiling) icon in the bottom right corner of the Unity status bar to stop.
    5. Click Build and Run.

    iOS

    1. Select the File > Build Settings menu option.
    2. Select iOS in the Platform list.
    3. Click Switch Platform to select iOS as the target platform.
    4. Wait for the spinner (compiling) icon in the bottom right corner of the Unity status bar to stop.
    5. Click Build and Run.

  1. If you haven't yet connected your app to your Firebase project, do so from the Firebase console.
  2. Enable anonymous auth:
    1. In the Firebase console, open the Auth section.
    2. On the Sign-in Methods page, enable the Anonymous sign-in method.

Authenticate with Firebase anonymously

When a signed-out user uses an app feature that requires authentication with Firebase, sign in the user anonymously by completing the following steps:

The FirebaseAuth class is the gateway for all API calls. It is accessable through FirebaseAuth.DefaultInstance.
Firebase.Auth.FirebaseAuth auth = Firebase.Auth.FirebaseAuth.DefaultInstance;
1. Call Firebase.Auth.FirebaseAuth.SignInAnonymouslyAsync.
auth.SignInAnonymouslyAsync().ContinueWith(task => {
  if (task.IsCanceled) {
    Debug.LogError("SignInAnonymouslyAsync was canceled.");
    return;
  }
  if (task.IsFaulted) {
    Debug.LogError("SignInAnonymouslyAsync encountered an error: " + task.Exception);
    return;
  }

  Firebase.Auth.FirebaseUser newUser = task.Result;
  Debug.LogFormat("User signed in successfully: {0} ({1})",
      newUser.DisplayName, newUser.UserId);
});

Convert an anonymous account to a permanent account

When an anonymous user signs up to your app, you might want to allow them to continue their work with their new account—for example, you might want to make the items the user added to their shopping cart before they signed up available in their new account's shopping cart. To do so, complete the following steps:

  1. When the user signs up, complete the sign-in flow for the user's authentication provider up to, but not including, calling one of the methods. For example, get the user's Google ID token, Facebook access token, or email address and password.
  2. Get an for the new authentication provider:

  3. Pass the object to the sign-in user's method:

If the call to succeeds, the user's new account can access the anonymous account's Firebase data.

Next steps

Now that users can authenticate with Firebase, you can control their access to data in your Firebase database using Firebase rules.

Send feedback about...

Need help? Visit our support page.