Flutter, Firebase, and Google Sign In 7.1.0

Oct 15, 2025

In typical Google fashion, the google_sign_in package was updated recently and if you missed the migration guide, your apps are broken. In this post, I’ll walk you through using version 7.1.0 of the google_sign_in package with Firebase and Flutter.

Setup

To get started, add the newest google_sign_in version to your pubspec.yaml:

google_sign_in: ^7.1.0

If you don’t have one already, create a new Firebase project in the Firebase console and then navigate to the authentication tab. Under “Sign-in method”, select “Add new provider” and choose “Google”.

Create a Web Client ID

You can create a web client ID a few ways.

Use Flutterfire Configure

Use the Google Cloud Console

Once you have the client ID, add it to your environment variables file. I typically create a config.json file in my assets folder and load my variables from that using String.fromEnvironment:

{
  "SERVER_CLIENT_ID": "YOUR_CLIENT_ID"
}

await GoogleSignIn.instance.initialize(
        serverClientId: const String.fromEnvironment("SERVER_CLIENT_ID"));

Setup iOS

You will need an iOS client ID to sign in with Google on iOS. To get one of these:

Log into your Google Cloud Console
Navigate to APIs & Services
Select “Create credentials”
Select OAuth Client ID
Choose iOS from the application type dropdown
Fill in each of the fields and click save

Once you have the client ID, copy it and add it to your Info.plist file.

https://firebase.google.com/docs/auth/flutter/federated-auth

Errors

Developer console is not set up correctly.

GoogleSignInException(code GoogleSignInExceptionCode.unknownError, [28444] Developer console is not set up correctly., null)

As pointed out in the docs, “[clientId] is the identifier for your client application, as provided by the Google Sign In server configuration”. In other words, you need to set the serverClientId to a web client ID on Android, not an android client ID.

serverClientID must be provided

Failed to sign in with Google: GoogleSignInException(code GoogleSignInExceptionCode.clientConfigurationError, serverClientId must be provided on Android, null)

Ensure that you are initializing the GoogleSignIn instance before calling any other methods.

await GoogleSignIn.instance
        .initialize(serverClientId: const String.fromEnvironment("ANDROID_CLIENT_ID"));

Execution failed for task ‘:app:checkDebugDuplicateClasses’.

Execution failed for task ‘:app:checkDebugDuplicateClasses’. Querying the mapped value of provider(java.util.Set) before task ‘:app:processDebugGoogleServices’ has completed is not supported

Update the Kotlin version in android/gradle/wrapper/gradle-wrapper.properties and android/settings.gradle to the latest Kotlin version (ex. 8.10):

distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-8.10-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists

plugins {
    id "dev.flutter.flutter-plugin-loader" version "1.0.0" // apply true
    id "com.android.application" version "8.3.0" apply false
    // START: FlutterFire Configuration
    id "com.google.gms.google-services" version "4.3.14" apply false
    id "com.google.firebase.crashlytics" version "2.8.1" apply false
    // END: FlutterFire Configuration
    id "org.jetbrains.kotlin.android" version "1.8.10" apply false
}