Adding OAuth Providers (Google, GitHub) in Lovable Auth Flow

 
Step One: Configuring OAuth Credentials
 

• In your Lovable Auth project, create a new file named oauthConfig.js inside your authentication folder. This file will store your OAuth credentials for different providers.
• Copy and paste the following code into oauthConfig.js. Replace placeholder text with your actual OAuth credentials:

  
  const oauthProviders = {
      google: {
          clientId: 'YOUR_GOOGLE_CLIENT\_ID',
          clientSecret: 'YOUR_GOOGLE_CLIENT\_SECRET',
          redirectUri: 'https://yourapp.com/auth/google/callback'
      },
      facebook: {
          clientId: 'YOUR_FACEBOOK_CLIENT\_ID',
          clientSecret: 'YOUR_FACEBOOK_CLIENT\_SECRET',
          redirectUri: 'https://yourapp.com/auth/facebook/callback'
      }
  };
  
  module.exports = oauthProviders;
      

  
  

 
Step Two: Adding OAuth Routes
 

• Open your existing authentication routes file (for example, authRoutes.js) in your authentication folder. If this file does not exist, create it.
• Add the following code to define routes that handle OAuth initiation and callbacks:

  
  const express = require('express');
  const router = express.Router();
  const oauthConfig = require('./oauthConfig');
  const { initiateOAuth, handleOAuthCallback } = require('./oauthHandlers');
  
  // Route to initiate Google OAuth flow
  router.get('/auth/google', (req, res) => {
      initiateOAuth('google', req, res);
  });
  // Route to handle Google OAuth callback
  router.get('/auth/google/callback', (req, res) => {
      handleOAuthCallback('google', req, res);
  });
  // Similarly, add routes for Facebook if needed
  router.get('/auth/facebook', (req, res) => {
      initiateOAuth('facebook', req, res);
  });
  router.get('/auth/facebook/callback', (req, res) => {
      handleOAuthCallback('facebook', req, res);
  });
  module.exports = router;
      

  
  

 
Step Three: Creating OAuth Handler Functions
 

• Create a new file named oauthHandlers.js in your authentication folder. This file will contain functions that actually process OAuth requests and responses.
• Paste in the following code. This uses the simple-oauth2 library. In Lovable, since there is no terminal access, you include dependencies by requiring them in your code. (Lovable will automatically load these if they are specified in your project configuration.)

  
  const simpleOauth2 = require('simple-oauth2');
  const oauthConfig = require('./oauthConfig');
  
  const oauthClients = {};
  // Setup the OAuth client for a specific provider
  function getClient(provider) {
      if (!oauthClients[provider]) {
          const config = oauthConfig[provider];
          oauthClients[provider] = simpleOauth2.create({
              client: {
                  id: config.clientId,
                  secret: config.clientSecret
              },
              auth: {
                  tokenHost: 'https://provider.com', // Replace with the provider's token host URL
                  authorizePath: '/oauth/authorize',
                  tokenPath: '/oauth/token'
              }
          });
      }
      return oauthClients[provider];
  }
  function initiateOAuth(provider, req, res) {
      const client = getClient(provider);
      const redirectUri = oauthConfig[provider].redirectUri;
      const authorizationUri = client.authorizationCode.authorizeURL({
          redirect_uri: redirectUri,
          scope: 'profile email',
          state: Math.random().toString(36).substring(7)
      });
      res.redirect(authorizationUri);
  }
  async function handleOAuthCallback(provider, req, res) {
      const client = getClient(provider);
      const code = req.query.code;
      const options = {
          code: code,
          redirect_uri: oauthConfig[provider].redirectUri
      };
  try {
      const result = await client.authorizationCode.getToken(options);
      const token = client.accessToken.create(result);
      // Here, create a user session or handle token storage as needed
      res.send('Authentication successful!');
  } catch (error) {
      console.error('Access Token Error', error.message);
      res.status(500).json('Authentication failed');
  }
  
  }
  module.exports = {
      initiateOAuth,
      handleOAuthCallback
  };
      

  
  

 
Step Four: Integrating OAuth Options in the Frontend
 

• If you have a login page (for example, login.html), open it. Otherwise, create a new file named login.html in your public or views folder.
• Add the following code to present both traditional and OAuth login options:

  
  
  
  
      
  
  
      
  Login Options
      
      
  
          
          
          Login
      
      
      
          Login with Google
      
      
          Login with Facebook
      
  
  
      

 
Step Five: Connecting OAuth Routes in Your Main Application File
 

• Locate your main application file (commonly app.js or index.js).
• Ensure that your authentication routes are connected to your Express app by adding the following snippet:

  
  const express = require('express');
  const app = express();
  
  // Other middleware and configurations
  const authRoutes = require('./authRoutes');
  app.use(authRoutes);
  // Start the server on port 8080
  app.listen(8080, () => {
      console.log('Server is running on port 8080');
  });
      

  
  

 
Understanding OAuth in Lovable Authentication Flows
 

• OAuth allows your application to securely sign in users via a trusted provider (like Google, Facebook, etc.). The main idea is that your app never directly handles the user's password. Instead, it exchanges a temporary code for access tokens and refresh tokens.
• The best practices include keeping your client secret private; always using a secure connection (HTTPS); validating the state value to prevent CSRF attacks; and ensuring proper error handling.

 
Creating Your OAuth Configuration File
 

• In the Lovable code editor, create a new file and name it oauth\_config.js. This file holds your OAuth credentials and endpoints.
• Add the following code inside oauth\_config.js. Replace the placeholder text with the actual information provided by your OAuth provider.

  
  const oauthConfig = {
    clientId: "YOUR_CLIENT_ID",            // Your unique client ID from the OAuth provider
    clientSecret: "YOUR_CLIENT_SECRET",    // Keep this secret safe; do not expose it publicly
    authorizationEndpoint: "https://provider.com/oauth2/authorize",
    tokenEndpoint: "https://provider.com/oauth2/token",
    redirectUri: "https://your-app.com/callback"  // Make sure this URL is registered with your provider
  };
  
  module.exports = oauthConfig;
      

  
  

 
Setting Up the Authentication Routes
 

• Create a new file named authentication.js. This file will handle the paths that start the OAuth login process and process the callback with the authorization code.
• Insert the following code in authentication.js. It creates two routes: one for starting the login process, and one for handling the callback after the user grants permission.

  
  const express = require('express');
  const axios = require('axios');
  const oauthConfig = require('./oauth\_config');
  const router = express.Router();
  
  // Route to start OAuth login process
  router.get('/login', (req, res) => {
    // Create a random state parameter to help protect against CSRF attacks
    const state = Math.random().toString(36).substring(7);
    // Store the state in session storage if available (ensure you have session handling configured)
    // Build the authorization URL with necessary query parameters
    const authUrl = ${oauthConfig.authorizationEndpoint}?client_id=${oauthConfig.clientId}&redirect_uri=${encodeURIComponent(oauthConfig.redirectUri)}&response_type=code&scope=profile email&state=${state};
    res.redirect(authUrl);
  });
  // Callback route to handle OAuth response
  router.get('/callback', async (req, res) => {
    // Extract code and state parameters from query string
    const { code, state } = req.query;
    // Validate the state parameter with what you stored (implement this check for security)
    try {
      // Exchange the authorization code for access and refresh tokens
      const response = await axios.post(oauthConfig.tokenEndpoint, {
        code: code,
        client_id: oauthConfig.clientId,
        client_secret: oauthConfig.clientSecret,
        redirect_uri: oauthConfig.redirectUri,
        grant_type: 'authorization_code'
      });
  // Extract tokens from the response
  const { access_token, refresh_token } = response.data;
  
  // Store tokens securely (consider encryption or built-in secure storage on Lovable)
  res.send('You are logged in successfully!');
  
    } catch (error) {
      // Best practice is to log errors and provide user-friendly messages.
      console.error("Error during token exchange: ", error);
      res.status(500).send('There was an error during authentication.');
    }
  });
  module.exports = router;
      

  
  

 
Integrating the Authentication Routes Into Your App
 

• Locate your main application file (for example, app.js). Insert the following snippet to set up your server and mount the authentication routes. This code ensures that when users visit the /login or /callback endpoints, your application will handle the requests correctly.

  
  const express = require('express');
  const app = express();
  
  // Import your authentication routes
  const authRoutes = require('./authentication');
  // Mount the authentication routes at the root path
  app.use('/', authRoutes);
  // Default route to test if server is running
  app.get('/', (req, res) => {
    res.send('Welcome to your secure Lovable app!');
  });
  // Ensure your app listens on the specified port
  const port = process.env.PORT || 8080;
  app.listen(port, () => {
    console.log(Server running on port ${port});
  });
      

  
  

 
Handling Dependencies Without a Terminal
 

• Since Lovable does not have a terminal, dependencies are managed via code rather than command-line installation. Create a file named package.json in your project’s root directory and add the following to include required modules like Express and Axios.

  
  {
    "name": "lovable-oauth-app",
    "version": "1.0.0",
    "main": "app.js",
    "dependencies": {
      "express": "^4.17.1",
      "axios": "^0.21.1"
    },
    "scripts": {
      "start": "node app.js"
    }
  }
      

• This file tells Lovable which libraries your application uses. When the application starts, these dependencies will be loaded automatically.

 
Troubleshooting and Best Practices for Error Handling
 

• Always validate the incoming parameters, such as the code and state, to ensure they match what you expect.
• Log detailed errors on the server-side (without exposing them to the user) to help troubleshoot any issues during the OAuth flow.
• Make sure your OAuth provider is reachable and the credentials are accurate. Double-check that the redirect URI in your code matches the one registered with your OAuth provider.
• Configure proper error messages for token exchange failures or invalid states. This makes it easier to identify where in the process an error occurs without revealing sensitive information.