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

Aug 14, 2024 • 5 minute read

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

Prerequisites

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

Your Drip API credentials (you rockstar, you)
A Node.js and Express.js setup (I know you've got this)
A basic understanding of OAuth 2.0 (don't worry, we'll refresh your memory)

Setting up the project

Let's kick things off by initializing our project:

npm init -y
npm install express axios dotenv

Configuring Drip API credentials

First things first, let's keep those credentials safe:

// .env
DRIP_CLIENT_ID=your_client_id
DRIP_CLIENT_SECRET=your_client_secret
REDIRECT_URI=http://localhost:3000/callback

Implementing the authorization flow

Initiating the OAuth process

Time to get this party started:

const express = require('express');
const app = express();

app.get('/auth', (req, res) => {
  const authUrl = `https://www.getdrip.com/oauth/authorize?client_id=${process.env.DRIP_CLIENT_ID}&response_type=code&redirect_uri=${encodeURIComponent(process.env.REDIRECT_URI)}`;
  res.redirect(authUrl);
});

Handling the callback

Let's catch that callback like a pro:

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  // We'll use this code in the next step
});

Exchanging the code for access token

Now for the good stuff - let's get that token:

const axios = require('axios');

// Inside your callback route
const tokenResponse = await axios.post('https://www.getdrip.com/oauth/token', {
  client_id: process.env.DRIP_CLIENT_ID,
  client_secret: process.env.DRIP_CLIENT_SECRET,
  code,
  grant_type: 'authorization_code',
  redirect_uri: process.env.REDIRECT_URI
});

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

Refreshing the access token

Keep it fresh, keep it secure:

async function refreshToken(refresh_token) {
  const response = await axios.post('https://www.getdrip.com/oauth/token', {
    client_id: process.env.DRIP_CLIENT_ID,
    client_secret: process.env.DRIP_CLIENT_SECRET,
    grant_type: 'refresh_token',
    refresh_token
  });
  
  return response.data;
}

Securing the integration

Security is sexy, so let's add some PKCE to spice things up:

const crypto = require('crypto');

function generateCodeVerifier() {
  return crypto.randomBytes(32).toString('hex');
}

function generateCodeChallenge(verifier) {
  return crypto.createHash('sha256').update(verifier).digest('base64')
    .replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '');
}

Use these functions when initiating the OAuth process and exchanging the code.

Testing the authorization flow

Fire up your server and navigate to /auth. You should be redirected to Drip, then back to your callback URL with a shiny new access token. Feels good, doesn't it?

Error handling and edge cases

Always be prepared:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send('Something broke! But we're on it.');
});

Conclusion

And there you have it! You've just built a rock-solid authorization flow for your Drip integration. Pat yourself on the back – you've earned it. Remember, this is just the beginning. Now that you've got the auth flow down, the sky's the limit for what you can build with Drip's API.

Additional resources

Now go forth and integrate! Your users are going to love what you build. Happy coding!