How to build a public Stripe integration: Building the Auth Flow

Jul 19, 2024 • 6 minute read

Hey there, fellow JavaScript enthusiasts! Ready to dive into the world of Stripe Connect and build an awesome authorization flow? Let's get cracking!

Introduction

Stripe Connect is a powerhouse for marketplace and platform businesses. It allows you to connect your users' Stripe accounts to your platform, opening up a world of possibilities for seamless payments. Today, we're focusing on the crucial part of this integration: the authorization flow. Buckle up!

Prerequisites

Before we jump in, make sure you've got:

A Stripe account (duh!)
Node.js and Express.js set up
A basic grasp of OAuth 2.0 (don't worry, we'll refresh your memory)

Setting up the project

Let's start with the basics:

npm init -y
npm install express stripe dotenv

Create an index.js file, and let's rock and roll!

Configuring Stripe Connect

Head over to the Stripe Dashboard and register your platform. You'll get a client_id - keep it safe, we'll need it soon!

Building the Authorization Flow

This is where the magic happens. We're going to create a smooth authorization process that'll make your users go "Wow!"

Create the authorization URL

First, let's construct that authorization URL:

const authorizationUrl = `https://connect.stripe.com/oauth/authorize?response_type=code&client_id=${process.env.STRIPE_CLIENT_ID}&scope=read_write&redirect_uri=${encodeURIComponent(process.env.REDIRECT_URI)}`;

Pro tip: Add optional parameters like stripe_user[email] or stripe_user[country] to customize the experience.

Implement the authorization request endpoint

Now, let's send our users to Stripe:

app.get('/connect-with-stripe', (req, res) => {
  res.redirect(authorizationUrl);
});

Set up the redirect URI endpoint

This is where Stripe sends the user back with the authorization code:

app.get('/stripe/callback', async (req, res) => {
  const { code } = req.query;
  
  try {
    const response = await stripe.oauth.token({
      grant_type: 'authorization_code',
      code,
    });
    
    // Store the access_token securely
    // You might want to associate it with a user in your database
    
    res.send('Authorization successful!');
  } catch (err) {
    console.error('Error exchanging code for token:', err);
    res.status(500).send('Authorization failed');
  }
});

Handling errors and edge cases

Always be prepared! Here are some scenarios to handle:

Invalid state parameter: Compare the state you sent with what you received
User denies authorization: Stripe will send an error parameter
Token exchange fails: Catch and log the error, then inform the user

Testing the integration

Time to put on your tester hat! Use Stripe's test mode to simulate both successful and failed authorizations. It's like a dress rehearsal before the big show!

Best practices and security considerations

Remember, with great power comes great responsibility:

Store access tokens securely (please, no plain text in your database!)
Implement a token refresh mechanism
Always use HTTPS. Always.

Conclusion

And there you have it! You've just built a rock-solid authorization flow for your Stripe Connect integration. Pat yourself on the back – you've earned it!

Next steps? Start building out the rest of your integration. The sky's the limit!

Additional resources

Want to dive deeper? Check out:

Now go forth and create something awesome! Remember, every great platform started with a single line of code. Happy coding!