Step 1: Set Up Your Supabase Project

• Go to Supabase and sign up for an account if you haven't already.
• Create a new project by providing a name and selecting the region.
• Once your project is up and running, take note of the Project URL and Anon Key from the API settings in the Supabase dashboard. You'll need these later.

Step 2: Configure Google Authentication

• Go to the Google Developers Console and create a new project.
• Navigate to the OAuth consent screen and configure it (make sure to add your Supabase URL to the authorized domains).
• Go to Credentials, create an OAuth 2.0 Client ID, and get your Client ID and Client Secret.
• Back in the Supabase dashboard, navigate to Authentication > Providers and enable Google login.
• Input the Client ID and Client Secret from the previous step and save the settings.

Step 3: Configure Facebook Authentication

• Go to the Facebook Developers site and create a new app.
• Set up Facebook Login and make sure to include your Supabase URL in the Valid OAuth Redirect URIs.
• Get your App ID and App Secret from the dashboard.
• In the Supabase dashboard, navigate to Authentication > Providers and enable Facebook login.
• Input the App ID and App Secret and save the settings.

Step 4: Configure Apple Authentication

• Go to the Apple Developer Console and log in or create an account.
• Under Identifiers, create a new Identifier and select App IDs. Enable Sign In with Apple.
• Create a new Service ID and enable Sign In with Apple. Configure the Redirect URI with your Supabase URL.
• Create a private key in the Apple Developer Console and download the key file (.p8).
• Get the Key ID, Team ID, and Client ID.
• Go to the Supabase dashboard, navigate to Authentication > Providers and enable Apple login.
• Input the Key ID, Team ID, Client ID, and upload the .p8 file. Save the settings.

Step 5: Implement Social Login in Your Frontend

• Install Supabase client SDK in your frontend application using npm:
  npm install @supabase/supabase-js
• Initialize the Supabase client with your Project URL and Anon Key:
  import { createClient } from '@supabase/supabase-js';
const supabase = createClient('your-project-url', 'your-anon-key');
• Create login buttons and attach event listeners that call the specific Supabase method for social login:
  Login with Google
Login with Facebook
Login with Apple

document.getElementById('google-login').onclick = async () => {
const { user, session, error } = await supabase.auth.signInWithOAuth({ provider: 'google' });
if (error) console.error('Google login error:', error);
};

document.getElementById('facebook-login').onclick = async () => {
const { user, session, error } = await supabase.auth.signInWithOAuth({ provider: 'facebook' });
if (error) console.error('Facebook login error:', error);
};

document.getElementById('apple-login').onclick = async () => {
const { user, session, error } = await supabase.auth.signInWithOAuth({ provider: 'apple' });
if (error) console.error('Apple login error:', error);
};

• Handle user session and authentication states accordingly in your frontend application.

Step 6: Test Your Implementation

• Deploy your frontend application to your preferred hosting provider.
• Ensure your OAuth credentials are correctly set in the production environment.
• Test the social login buttons to make sure they correctly authenticate users.

Conclusion

• By following these steps, you should now have a fully functional social login system integrated into your application using Supabase.
• Always make sure to keep your OAuth credentials secure and never expose them in your frontend code.