How do I integrate Google sign in with my app?

To integrate Google Sign-In with your app, the exact steps depend on your platform, but the overall flow is usually:

1. Create a Google Cloud project
2. Configure OAuth consent screen
3. Create OAuth credentials
4. Add the Google Sign-In SDK / library
5. Implement the sign-in flow in your app
6. Verify the user on your backend if you have one

General setup

1) Create a project in Google Cloud

• Go to the Google Cloud Console
• Create a new project or select an existing one

2) Configure the OAuth consent screen

• In Google Cloud Console, open APIs & Services → OAuth consent screen
• Choose External if users outside your org will sign in
• Fill in app name, support email, and authorized domains
• Add test users if your app is still in testing

3) Create OAuth client credentials

Under APIs & Services → Credentials:

• Create an OAuth client ID
• Choose the app type:
  • Web application
  • Android
  • iOS
• Add the correct redirect URIs / package names / bundle IDs

4) Add the Google sign-in library

Web

Use Google Identity Services:

<script src="https://accounts.google.com/gsi/client" async defer></script>

Android

Use Google Identity Services / Google Sign-In via Play services depending on your setup:

• Add the Google auth dependency
• Configure your google-services.json

iOS

• Add the Google Sign-In SDK via Swift Package Manager, CocoaPods, or manual integration

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Example: Web sign-in

A basic button flow using Google Identity Services:

<div id="g_id_onload"
     data-client_id="YOUR_GOOGLE_CLIENT_ID"
     data-callback="handleCredentialResponse">
</div>

<div class="g_id_signin" data-type="standard"></div>

<script>
  function handleCredentialResponse(response) {
    console.log("ID token:", response.credential);
    // Send token to your server for verification
  }
</script>

Then on your backend, verify the ID token with Google before creating a session.

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Example: Backend token verification

If your app has a backend, don’t trust the client alone. Verify the token server-side.

Node.js example

import { OAuth2Client } from 'google-auth-library';

const client = new OAuth2Client('YOUR_GOOGLE_CLIENT_ID');

async function verifyGoogleToken(idToken) {
  const ticket = await client.verifyIdToken({
    idToken,
    audience: 'YOUR_GOOGLE_CLIENT_ID',
  });
  return ticket.getPayload();
}

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Important notes

• Use the correct client ID for your platform
• Make sure redirect URIs match exactly
• If you request sensitive scopes, Google may require verification
• If your app uses backend auth, exchange or verify the Google token and then create your own app session/JWT

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If you want, I can give you a step-by-step integration guide for:

• React web
• Android
• iOS / Swift
• Flutter
• React Native
• Node.js backend

Tell me your platform and I’ll provide the exact code.