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

Aug 3, 2024 • 7 minute read

Hey there, fellow JavaScript aficionado! Ready to dive into the world of Figma integrations? Today, we're going to tackle one of the most crucial aspects of building a public Figma integration: the authorization flow. Buckle up, because we're about to make your integration secure and user-friendly in no time.

Introduction

Figma integrations are a game-changer, allowing us to extend Figma's functionality and create awesome tools for designers. But before we can do any of that cool stuff, we need to nail the auth flow. It's like the bouncer at an exclusive club – it keeps the riffraff out and lets the VIPs (your users) in.

Prerequisites

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

A Figma developer account (if you don't have one, go grab it!)
A basic understanding of OAuth 2.0 (don't worry, we'll refresh your memory)
Node.js and Express.js set up and ready to roll

Got all that? Great! Let's get this party started.

Setting up the Figma App

First things first, let's get your Figma app set up:

Head over to your Figma account and create a new app.
Configure the OAuth settings. This is where you'll tell Figma where to send your users after they've authorized your app.
Grab your client ID and client secret. Guard these with your life (or at least with good security practices).

Implementing the Authorization Flow

Now for the main event – let's build that auth flow!

Initiating the auth request

We'll start by constructing the authorization URL and sending your users on a field trip to Figma's auth page:

const authUrl = `https://www.figma.com/oauth?client_id=${clientId}&redirect_uri=${redirectUri}&scope=file_read&state=${state}&response_type=code`;
res.redirect(authUrl);

Handling the callback

Once Figma sends the user back to your app, you'll need to handle that callback:

app.get('/oauth/callback', async (req, res) => {
  const { code, state } = req.query;
  // Verify state to prevent CSRF attacks
  if (state !== expectedState) {
    return res.status(400).send('Invalid state parameter');
  }
  // Exchange code for access token
  // ...
});

Exchanging the code for an access token

Time to trade that code for the golden ticket – the access token:

const tokenResponse = await axios.post('https://www.figma.com/api/oauth/token', {
  client_id: clientId,
  client_secret: clientSecret,
  redirect_uri: redirectUri,
  code,
  grant_type: 'authorization_code'
});

const { access_token, refresh_token } = tokenResponse.data;
// Store these securely

Refreshing the Access Token

Access tokens don't last forever, so let's implement a refresh mechanism:

async function refreshAccessToken(refreshToken) {
  const response = await axios.post('https://www.figma.com/api/oauth/refresh', {
    client_id: clientId,
    client_secret: clientSecret,
    refresh_token: refreshToken
  });
  return response.data.access_token;
}

Using the Access Token

Now that you've got the access token, you're ready to make authenticated requests to the Figma API:

const figmaApiResponse = await axios.get('https://api.figma.com/v1/me', {
  headers: { 'Authorization': `Bearer ${accessToken}` }
});

Security Considerations

Security isn't just a buzzword – it's crucial. Here are some tips:

Always use HTTPS
Store your client secret and tokens securely (environment variables are your friend)
Implement PKCE for an extra layer of security

Testing the Auth Flow

Before you pop the champagne, make sure to thoroughly test your auth flow. Try some manual testing and consider setting up automated tests to catch any sneaky bugs.

Conclusion

And there you have it! You've just built a rock-solid auth flow for your Figma integration. Pat yourself on the back – you've laid the foundation for something awesome.

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

Additional Resources

Want to dive deeper? Check out these resources:

Now go forth and create something amazing. Happy coding!