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

Hey there, fellow developer! Ready to dive into the world of Coda integrations? Today, we're going to focus on one of the most crucial aspects of building a public integration: the authorization flow. Don't worry, it's not as daunting as it sounds. Let's break it down step by step.

Introduction

Coda integrations are a fantastic way to extend the functionality of your docs and make them even more powerful. But before we can start making cool API calls, we need to set up a robust auth flow. This is what allows users to securely connect their Coda account to your integration. It's like the bouncer at an exclusive club – it makes sure only the right people get in.

Prerequisites

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

• A Coda developer account (if you don't have one, go grab it – it's free!)
• A basic understanding of OAuth 2.0 (don't sweat it if you're rusty, we'll cover the essentials)
• Node.js and Express.js set up on your machine

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

Setting up the Coda Integration

First things first, head over to Coda's developer portal and create a new integration. It's pretty straightforward:

1. Log in to the Coda developer portal
2. Click on "Create New Integration"
3. Fill in the basic details

Once you've done that, you'll get a client ID and client secret. These are like your integration's username and password, so keep them safe!

Implementing the Authorization Flow

Now for the fun part – let's build this auth flow!

Initiating the auth request

We'll start by constructing the authorization URL. It'll look something like this:

const authUrl = `https://coda.io/oauth2/authorize?client_id=${clientId}&redirect_uri=${redirectUri}&scope=${scope}&response_type=code`;

When a user wants to connect their Coda account, you'll redirect them to this URL. Coda will handle the heavy lifting of authenticating the user.

Handling the callback

After the user grants permission, Coda will redirect them back to your specified redirect URI with an authorization code. You'll need to set up a route to handle this:

app.get('/callback', async (req, res) => {
  const code = req.query.code;
  // Exchange this code for an access token
});

Exchanging the code for an access token

Now we've got the code, let's swap it for an access token:

const response = await axios.post('https://coda.io/oauth2/token', {
  grant_type: 'authorization_code',
  client_id: clientId,
  client_secret: clientSecret,
  code: code,
  redirect_uri: redirectUri
});

const accessToken = response.data.access_token;

Make sure to store this access token securely – you'll need it for making API calls.

Refreshing the Access Token

Access tokens don't last forever, so we need to implement a refresh mechanism:

const refreshToken = async () => {
  const response = await axios.post('https://coda.io/oauth2/token', {
    grant_type: 'refresh_token',
    client_id: clientId,
    client_secret: clientSecret,
    refresh_token: storedRefreshToken
  });

  return response.data.access_token;
};

Making Authenticated Requests

Now you're ready to make API calls! Just include the access token in your requests:

const response = await axios.get('https://coda.io/apis/v1/docs', {
  headers: {
    Authorization: `Bearer ${accessToken}`
  }
});

Security Considerations

Security is crucial, so keep these points in mind:

• Always use HTTPS
• Store tokens securely (consider using environment variables)
• Implement PKCE (Proof Key for Code Exchange) for added security

Testing the Auth Flow

Before you release your integration into the wild, make sure to test it thoroughly. Try different scenarios:

• Happy path (everything works as expected)
• Token expiration and refresh
• Invalid tokens
• Revoked permissions

Conclusion

And there you have it! You've just built a secure auth flow for your Coda integration. Pretty cool, right? From here, you can start adding all sorts of awesome features to your integration.

Remember, the auth flow is the foundation of your integration. Get this right, and you're well on your way to creating something amazing.

Additional Resources

Want to dive deeper? Check out:

• Coda API documentation
• OAuth 2.0 best practices

Happy coding, and have fun building your Coda integration!