Google releases open-source Sign in with Google plugin for Unity

• The plugin supports Unity 6.5 and Google account sign-in on Android and iOS.
• The Android version uses Credential Manager while the iOS version uses Google's GIDSignIn SDK.
• Developers can configure their sign-in details directly within the Unity Editor.
• The plugin supports backend services including Firebase Authentication, Supabase and Auth0.

Google has released an open-source Sign in with Google plugin for Unity, allowing developers to add Google account authentication to mobile games on Android and iOS.

Available on GitHub, the plugin supports Unity 6.5 and replaces an older implementation that faced compatibility issues with modern Android development tools.

The new plugin uses native authentication tools on both platforms. On Android, it connects to Credential Manager through Kotlin, while the iOS version uses Google's GIDSignIn SDK through Objective-C++.

Backend support 

The plugin also includes configuration options within the Unity Editor, allowing developers to enter their Web Client ID and iOS Reversed Client ID without manually changing platform files.

Google has designed the integration to work with different backend services. It retrieves a signed Google ID token that developers can access through Unity C# scripts and use with services such as Firebase Authentication, Supabase and Auth0, or their own backend systems.

This means studios can add Google account sign-in without replacing their existing player account systems. However, the plugin primarily retrieves Google ID tokens rather than providing a complete player account management service.

Google said the new implementation is designed to reduce integration work and address compatibility problems found in older versions.