Introduction

Authentication is a crucial aspect of modern web applications, and offering social login options can significantly improve user experience and increase sign-up rates. Supabase provides an easy way to implement social logins, allowing users to authenticate using their preferred social media accounts. In this blog post, we'll explore how to set up and implement social logins in your Supabase project.

Why Use Social Logins?

Before diving into the implementation, let's quickly discuss the benefits of social logins:

1. Simplified user experience
2. Reduced friction during sign-up
3. Increased conversion rates
4. Access to additional user data (with user consent)
5. Enhanced security through OAuth protocols

Setting Up Social Providers in Supabase

Supabase supports various social login providers, including Google, Facebook, GitHub, and more. Let's walk through the process of setting up Google authentication as an example.

Step 1: Create a Google OAuth Client

1. Go to the Google Cloud Console
2. Create a new project or select an existing one
3. Navigate to "APIs & Services" > "Credentials"
4. Click "Create Credentials" and select "OAuth client ID"
5. Choose "Web application" as the application type
6. Add your Supabase project URL to the "Authorized JavaScript origins"
7. Add your Supabase callback URL to the "Authorized redirect URIs" (e.g., https://[YOUR_PROJECT_ID].supabase.co/auth/v1/callback)
8. Click "Create" and note down the Client ID and Client Secret

Step 2: Configure Supabase Auth Settings

1. Open your Supabase project dashboard
2. Navigate to "Authentication" > "Providers"
3. Find the Google provider and enable it
4. Enter the Client ID and Client Secret obtained from Google
5. Save the changes

Implementing Social Login in Your Application

Now that we've set up the Google provider, let's implement the social login in your application. We'll use the Supabase JavaScript client for this example.

First, install the Supabase client:

npm install @supabase/supabase-js

Then, initialize the Supabase client in your application:

import { createClient } from '@supabase/supabase-js'

const supabase = createClient('YOUR_SUPABASE_PROJECT_URL', 'YOUR_SUPABASE_ANON_KEY')

To implement the Google login, you can use the following code:

async function signInWithGoogle() {
  const { user, session, error } = await supabase.auth.signIn({
    provider: 'google',
  })

  if (error) {
    console.error('Error signing in with Google:', error.message)
  } else {
    console.log('Signed in successfully:', user)
    // Handle successful sign-in (e.g., redirect to dashboard)
  }
}

You can call this function when a user clicks on the "Sign in with Google" button:

<button onclick="signInWithGoogle()">Sign in with Google</button>

Handling the Authentication Flow

When a user clicks the sign-in button, they'll be redirected to Google's authentication page. After successful authentication, they'll be redirected back to your application. You'll need to handle this redirect and check for the authenticated user.

Add the following code to your application's entry point (e.g., App.js or index.js):

useEffect(() => {
  const { data: authListener } = supabase.auth.onAuthStateChange((event, session) => {
    if (event === 'SIGNED_IN') {
      // User has signed in, update your app state accordingly
      console.log('User signed in:', session.user)
    }
  })

  return () => {
    authListener.unsubscribe()
  }
}, [])

This code listens for authentication state changes and logs the user information when they successfully sign in.

Adding Multiple Social Login Providers

To add more social login providers, repeat the process of creating OAuth clients for each provider (e.g., Facebook, GitHub) and configure them in your Supabase project settings. Then, you can create similar sign-in functions for each provider:

async function signInWithFacebook() {
  const { user, session, error } = await supabase.auth.signIn({
    provider: 'facebook',
  })
  // Handle the result
}

async function signInWithGitHub() {
  const { user, session, error } = await supabase.auth.signIn({
    provider: 'github',
  })
  // Handle the result
}

Customizing the User Experience

To provide a seamless experience for your users, consider the following tips:

1. Use provider-specific buttons with appropriate branding
2. Offer a choice between social logins and traditional email/password authentication
3. Implement error handling and display user-friendly error messages
4. Add loading indicators during the authentication process

Security Considerations

While social logins can enhance security, it's essential to keep the following points in mind:

1. Always use HTTPS for your application
2. Implement proper session management
3. Be cautious with the scope of permissions requested from social providers
4. Regularly update your Supabase client and dependencies
5. Monitor and review authentication logs for suspicious activity

Conclusion

Implementing social logins with Supabase is a straightforward process that can significantly improve your application's user experience. By following this guide, you've learned how to set up social providers, implement the authentication flow, and handle multiple login options.