Getting Started with Firebase Authentication in Unity

I was looking for a third-party account SDK for an app aimed at international users. After comparing the options, I chose Firebase.

Integration was initially rough. I tried exporting an AAR from Android Studio into Unity, then exporting an Android Studio project from Unity. Neither attempt worked. I had not yet tried iOS.

The real problem was that I had not read the official documentation carefully. Google supplied a Unity package: importing it and doing a little configuration in the Firebase console was much simpler.

Official Firebase Authentication Unity guide

Register the app in Firebase#

Registering the app in the Firebase console

Make sure the registered package name matches the app’s final package name.

Add the SHA certificate fingerprint#

Add the fingerprint in the app settings:

Adding a SHA certificate fingerprint

Download google-services.json#

In the project described in this November 2022 note, I placed the file in Asset/StreamingAssets in the Unity project.

Enable an authentication provider#

Enabling an authentication provider

Import FirebaseAuth.unitypackage#

Import the authentication package into Unity.

Add test code#

The following code tests account creation with an email address and password:

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auth.CreateUserWithEmailAndPasswordAsync(email, password)
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            .ContinueWith(task =>
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            {
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                if (task.IsCanceled)
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                {
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                    Debug.LogError("CreateUserWithEmailAndPasswordAsync was canceled.");
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                    return;
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                }
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                if (task.IsFaulted)
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                {
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                    Debug.LogError(
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                        "CreateUserWithEmailAndPasswordAsync encountered an error: "
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                            + task.Exception
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                    );
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                    return;
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                }
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                // Firebase user has been created.
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                FirebaseUser newUser = task.Result;
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                Debug.LogFormat(
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                    "Firebase user created successfully: {0} ({1})",
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                    newUser.DisplayName,
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                    newUser.UserId
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                );
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            });