App Store Requirement: If you implement Google Sign-In for iOS, Apple requires that you must also implement Apple Sign-In to pass the App Store review process. This is a mandatory requirement from Apple, not optional.

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Prerequisites

Before setting up Google Sign-In, make sure you have:

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Step 1: Set Up a Google Cloud Project

If you’ve already set up Push Notifications for Android, you likely have a Google Cloud project. You can use the same project for Google Sign-In.
1

Enable the Google Sign-In API

  • Select your Google Cloud project
  • Click on APIs & Services in the left menu
  • Click ”+ ENABLE APIS AND SERVICES” at the top
  • Search for “Google Identity” and select “Google Identity Services API”
  • Click Enable
2

Configure the consent screen

  • Pick the OAuth Consent Screen option in the left menu
  • Click “Get started”
3

Complete the consent screen configuration

  • App Information: Fill it out the form with App Name and User support email
  • Audience: pick “External”
  • Contact Information: These email addresses are for Google to notify you about any changes to your project
  • Finish: Agree to the Google API Services: User Data Policy
  • Press “Create”

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Step 2: Create Web OAuth Client ID

You need to create a Web OAuth Client ID for Supabase authentication to work properly. This client is required regardless of which platform (iOS/Android) you’re targeting.
1

Access the Google Cloud Console

In the Google Cloud console, navigate to Menu > Google Auth platform > Clients
2

Create OAuth Client

  1. Click the Create Client button
  2. For Application type, select Web application
  3. In the Name field, enter a descriptive name for your credential (e.g., “Supabase Web Client”)
3

Configure Authorized URIs

Set up the appropriate URIs for your application:
  1. Under Authorized JavaScript origins, click Add URI
    • Enter your Supabase project URL from .env (e.g. https://yourprojectref.supabase.co)
  2. Under Authorized redirect URIs, click Add URI
    • Enter your Supabase project URL from .env + /auth/v1/callback (e.g. https://yourprojectref.supabase.co/auth/v1/callback)
4

Generate and Save Credentials

  1. Click Create to generate your OAuth client ID
  2. Your new credentials will appear after they are created:
  3. Save your Client ID and Client Secret - you’ll need these to configure Supabase
This web client is required for Supabase authentication integration. You’ll use these credentials in the Supabase dashboard to enable Google authentication.

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Step 3: Configure Supabase Google Provider

1

Access Supabase Authentication Settings

  1. Go to your Supabase Dashboard
  2. Select your project
  3. Navigate to Authentication in the left sidebar
  4. Select Sign In / Providers tab
2

Configure Google Provider

  1. Find and click on the Google provider
  2. Toggle the switch to Enable the Google provider
  3. Client ID: Enter your Client ID (e.g. your-web-client-id)
  4. Client Secret: Enter your Client Secret
  5. Callback URL (for OAuth): Verify that the Callback URL matches the Redirect URI you set up in the Google Cloud Console (e.g. https://yourprojectref.supabase.co/auth/v1/callback)
  6. Click Save to apply your changes

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Step 4: Create Platform-Specific OAuth Clients

After setting up the web client for Supabase, you need to create platform-specific OAuth clients for each platform you want to support.
1

Get SHA-1 Certificate Fingerprint from Expo Dashboard

  1. Go to the Expo Dashboard Project Credentials page
  2. Click on your Application Identifier (e.g., com.buildwithai.travelapp)
  3. Under the Android upload keystore section, find and copy the SHA-1 Fingerprint
  4. Save this value for the next step.
2

Create Android OAuth Client ID

  1. In the Google Cloud console, navigate to Menu > Google Auth platform > Clients
  2. Click the Create Client button
  3. Select Android as the application type
3

Configure Android Client Settings

  1. Enter a descriptive Name for your Android application
  2. Enter your app’s Package name in the Package name field
    • This should match the package name in your app.json (e.g., com.buildwithai.travelapp)
  3. Enter the SHA-1 certificate fingerprint you copied earlier
  4. Click the Create button
  5. Save your Android Client ID - you’ll need it for your app configuration

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Step 5: Enable Google Sign-In in Your App

Now that you’ve set up all the necessary OAuth clients, you need to configure your app to use Google Sign-In:
1

Implementation

Follow the implementation instructions in the integrations/google-auth/README.md file included in your boilerplate codebase. This file contains all necessary steps for setting up Google Sign-In in your application, including:
  • File activation
  • Package installation
  • Environment variables configuration
  • Platform-specific setup for iOS and Android
  • Code enablement
Once you’ve completed the implementation steps, the Google Sign-In button will appear in the authentication screens and be fully functional on both iOS and Android.

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Testing Your Configuration

  1. Rebuild development build and open it on your device
  2. Navigate to the sign-in screen
  3. Tap the “Sign in with Google” button
  4. Complete the Google authentication flow
  5. Verify that you are successfully signed in to your app

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Additional Resources