I'll create a website that allows users to login with their Google account and display their emails using Node.js for the backend and HTML/CSS/JS for the frontend.

First, let's set up the necessary environment variables:

Great! Now I'll create a complete solution for a website that allows users to login with their Google account and view their emails.

How to Run the Application

1. Set up Google OAuth Credentials:

   • Go to the Google Cloud Console
   • Create a new project
   • Navigate to "APIs & Services" > "Credentials"
   • Click "Create Credentials" > "OAuth client ID"
   • Set the application type to "Web application"

   • Add authorized redirect URIs:

     • For local development: http://localhost:3000/auth/google/callback
     • For production: https://your-domain.com/auth/google/callback
   • Note your Client ID and Client Secret

2. Install Dependencies:

   npm install

3. Run the Application:

   npm start

4. Access the Application:

   • Open your browser and navigate to http://localhost:3000

How It Works

1. Authentication Flow:

   • User clicks "Sign in with Google" button
   • They're redirected to Google's authentication page
   • After successful authentication, Google redirects back to our callback URL
   • The server exchanges the authorization code for access tokens
   • User is redirected to the dashboard

2. Email Retrieval:

   • The dashboard makes an API request to /api/emails
   • The server uses the stored access token to fetch emails from Gmail API
   • Emails are displayed in a clean, responsive interface

3. Security Features:

   • Session-based authentication
   • Secure token storage
   • Error handling for authentication failures

This application demonstrates a complete OAuth flow with Google and accessing the Gmail API to retrieve user emails.

Please make sure to add the following environment variable to your project: