Google Login With Supabase: A Simple Guide

Hey guys! Ever wanted to integrate Google login into your app, but felt a bit lost in the process? Fear not! This guide breaks down the steps to easily implement Google social login using Supabase. Supabase is a fantastic open-source alternative to Firebase, offering a suite of tools, including authentication, to help you build amazing applications. We'll be focusing on how to set up Google login, which allows your users to authenticate using their Google accounts. This enhances user experience and simplifies the registration process. Let's dive in and get those Google logins working!

Setting Up Your Supabase Project

First things first, you'll need a Supabase project. If you haven't already, head over to supabase.com and create one. It's super straightforward, and they have a great free tier to get you started. Once your project is created, make sure you have your project's API keys handy. You'll find these in the project settings under the 'API' section. You'll need the anon key and the service_role key. Keep these safe! Never expose your service role key in your client-side code, as it grants full access to your database. The anon key (or public key) is meant for the client-side use. Now let's explore how to configure Google login within your Supabase project. This involves setting up the necessary authentication providers and redirect URLs.

Enabling Google as an OAuth Provider

Inside your Supabase project dashboard, navigate to the 'Authentication' section. You'll find a 'Providers' tab where you can enable various social login options. Click on 'Google' to start the setup. You'll be prompted to enter your Google OAuth credentials, which we'll obtain from the Google Cloud Console. This is where the magic happens, so pay close attention! When you enable Google as a provider, you're essentially telling Supabase that you want to allow users to sign in with their Google accounts.

Configuring Your Google Cloud Console

This is where you'll create the OAuth credentials required by Supabase. Head over to the Google Cloud Console and select the project associated with your application (or create a new one). Navigate to 'APIs & Services' -> 'Credentials'. Click on 'Create Credentials' and select 'OAuth client ID'. You'll be asked to configure the consent screen first. Fill in the necessary details, such as your application name and authorized domains. Remember to include your application's privacy policy and terms of service URLs.

Now, select the application type. For most web applications, you'll choose 'Web application'. You'll need to specify authorized JavaScript origins and redirect URIs. The redirect URI is especially important; this is where Google will redirect the user after they've authenticated. In your Supabase project, you will find the redirect URL on the social login setting, it should look something like https://your-project-ref.supabase.co/auth/v1/callback. Copy and paste this into the redirect URI field in your Google Cloud Console. Once you've created your OAuth client ID, you'll get a client ID and client secret. Copy and paste these into your Supabase Google provider settings. Voila! You have finished setting up your Google Cloud Console configuration.

Implementing Google Login in Your App

Alright, now that you've got your Supabase project and Google Cloud Console set up, it's time to integrate the login into your app. This involves using the Supabase JavaScript client to initiate the Google authentication flow.

Installing the Supabase JavaScript Client

First, make sure you have the Supabase JavaScript client installed in your project. You can do this using npm or yarn:

npm install @supabase/supabase-js
# or
yarn add @supabase/supabase-js

This package provides the necessary tools to interact with your Supabase backend, including the authentication services. Once installed, import the client into your project:

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

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

Replace YOUR_SUPABASE_URL and YOUR_SUPABASE_ANON_KEY with your actual Supabase project URL and anon key, which you obtained earlier.

Initiating the Google Login Flow

Here's the core part: the code that handles the login. You'll need a button or some UI element that triggers the Google login flow. When a user clicks this button, you'll call the signInWithOAuth method provided by the Supabase client.

async function signInWithGoogle() {
  const { data, error } = await supabase.auth.signInWithOAuth({
    provider: 'google',
    options: {
      redirectTo: 'YOUR_REDIRECT_URI',
    },
  });

  if (error) {
    console.error('Error signing in with Google:', error.message);
  } else {
    console.log('Successfully initiated Google sign-in:', data);
  }
}

Make sure to replace YOUR_REDIRECT_URI with the same redirect URI you configured in your Google Cloud Console and Supabase settings. This is crucial for Google to redirect the user back to your app after authentication. The signInWithOAuth method handles the heavy lifting, redirecting the user to Google for authentication. Once the user authenticates with Google, they will be redirected back to your application at the specified redirectTo URL. Supabase will handle the rest, creating a user session in your app.

Handling the Authentication Callback

After the user authenticates with Google, they'll be redirected to your redirectTo URL. Supabase will automatically handle this callback. You typically don't need to write any specific code to handle this part unless you need to perform additional actions after the user logs in, such as updating their profile information or redirecting them to a specific page. You can retrieve the user's session information using supabase.auth.getSession() or by subscribing to auth state changes:

supabase.auth.onAuthStateChange((event, session) => {
  if (event === 'SIGNED_IN') {
    console.log('User signed in:', session);
    // Redirect or update UI
  } else if (event === 'SIGNED_OUT') {
    console.log('User signed out');
    // Redirect or update UI
  }
});

This code listens for changes in the user's authentication state. When a user successfully signs in, the SIGNED_IN event is triggered, and you can access the user's session data. When a user signs out, the SIGNED_OUT event is triggered. This allows you to update the UI or redirect the user to the appropriate page.

Advanced Customization and Best Practices

Now that you've got the basics down, let's explore some advanced customization options and best practices to enhance your implementation. This includes customizing the redirect URL, handling errors gracefully, and storing additional user information.

Customizing the Redirect URL

While the default redirect URL provided by Supabase works well, you might want to customize it to handle specific scenarios or redirect users to a particular page after they've logged in. You can achieve this by specifying the redirectTo option in the signInWithOAuth method. Ensure that the redirect URI matches the one configured in your Google Cloud Console and Supabase settings. This helps maintain a seamless user experience.

Handling Errors Gracefully

It's important to handle errors that may occur during the authentication process. The signInWithOAuth method returns an error object. Always check for errors and display informative messages to the user. This helps users understand what went wrong and how to resolve the issue.

const { data, error } = await supabase.auth.signInWithOAuth({ ... });

if (error) {
  console.error('Authentication error:', error.message);
  alert('An error occurred during sign-in. Please try again.');
}

Storing Additional User Information

Often, you'll need to store additional user information beyond what's provided by Google. You can use Supabase's database to store this data. When a user successfully signs in, you can query Google's user information and insert or update the user's profile information in your database.

supabase.auth.onAuthStateChange(async (event, session) => {
  if (event === 'SIGNED_IN') {
    const { data: { user }, error } = await supabase.auth.getUser()

    if (error) {
      console.error('Error fetching user:', error)
      return
    }

    // Store additional user data
    const { data: profileData, error: profileError } = await supabase
      .from('profiles')
      .upsert({ id: user.id, email: user.email, ... }) // upsert to update

    if (profileError) {
      console.error('Error updating profile:', profileError)
    }
  }
})

This example shows how to retrieve the user's information and store it in a profiles table in your Supabase database. You can customize the fields to store additional user data, such as their name, profile picture, or any other relevant information. This ensures that you have all the necessary information to personalize the user experience within your application.

Troubleshooting Common Issues

Running into problems? Don't worry, it's all part of the process! Here are some common issues and how to solve them. Let's make sure things are working smoothly. Make sure to double-check these common pitfalls.

Incorrect Redirect URI

One of the most common issues is an incorrect redirect URI configuration. Ensure that the redirect URI in your Google Cloud Console and Supabase settings exactly match. Any discrepancies can lead to authentication failures. This is the most frequent culprit, so carefully review your settings.

Client ID and Secret Mismatch

Double-check that the client ID and client secret you entered in your Supabase settings match those provided by Google. Even a small typo can cause authentication to fail. Always copy and paste these credentials to avoid errors.

CORS Errors

Cross-Origin Resource Sharing (CORS) errors can occur if your application is trying to access resources from a different domain. Make sure your application's domain is allowed in your Supabase project's CORS settings.

Google Account Permissions

Ensure that the Google account you're using has the necessary permissions to access the Google services required by your application. This may involve enabling certain APIs in the Google Cloud Console. Some APIs need to be explicitly enabled.

Network Issues

Sometimes, network issues can disrupt the authentication process. Verify that your application has a stable internet connection. Try clearing your browser's cache and cookies.

Conclusion: Google Login with Supabase

And there you have it, guys! You've successfully integrated Google login into your application using Supabase. This not only enhances user experience but also streamlines the authentication process. By following these steps, you can create a secure and user-friendly login system, simplifying the user onboarding process. Remember to always prioritize security and user privacy. Keep in mind that continuous learning and adaptation are essential. By keeping your code up to date and by following the best practices, you can create robust, secure, and user-friendly applications using Supabase. Happy coding!