Reading and Writing Data Using the ConvertKit API

Hey there, fellow JavaScript devs! Ready to dive into the world of ConvertKit API integration? Let's get our hands dirty with some code and learn how to sync data for a user-facing integration. Buckle up!

Authentication: Your Key to the Kingdom

First things first, you'll need an API key. Head over to your ConvertKit account settings and grab that key. It's your golden ticket to the API wonderland.

Here's how you'll use it in your requests:

const apiKey = 'your_api_key_here';
const headers = {
  'Authorization': `Bearer ${apiKey}`,
  'Content-Type': 'application/json'
};

Reading Data: What's in the Box?

Now that we're in, let's see what goodies ConvertKit has for us. We'll fetch subscribers, tags, and custom fields.

async function getSubscribers() {
  const response = await fetch('https://api.convertkit.com/v3/subscribers', { headers });
  return response.json();
}

async function getTags() {
  const response = await fetch('https://api.convertkit.com/v3/tags', { headers });
  return response.json();
}

Writing Data: Time to Make Our Mark

Got some data to push? Let's create subscribers, add tags, and update custom fields.

async function createSubscriber(email, firstName) {
  const body = JSON.stringify({ email, first_name: firstName });
  const response = await fetch('https://api.convertkit.com/v3/subscribers', {
    method: 'POST',
    headers,
    body
  });
  return response.json();
}

async function addTag(subscriberId, tagId) {
  const response = await fetch(`https://api.convertkit.com/v3/subscribers/${subscriberId}/tags/${tagId}`, {
    method: 'POST',
    headers
  });
  return response.json();
}

Syncing Data: Keeping Everything in Harmony

Now for the main event: syncing data. We'll implement a strategy that respects rate limits and handles errors like a champ.

async function syncSubscribers(localSubscribers) {
  for (const subscriber of localSubscribers) {
    try {
      await createSubscriber(subscriber.email, subscriber.firstName);
      console.log(`Synced ${subscriber.email}`);
      await new Promise(resolve => setTimeout(resolve, 1000)); // Respect rate limits
    } catch (error) {
      console.error(`Failed to sync ${subscriber.email}:`, error);
      // Implement retry logic here
    }
  }
}

Webhooks: Real-time Magic

Want to stay up-to-date in real-time? Webhooks are your friend. Set them up in your ConvertKit account, then handle the incoming data like this:

app.post('/webhook', (req, res) => {
  const { event, data } = req.body;
  switch (event) {
    case 'subscriber.created':
      // Handle new subscriber
      break;
    case 'subscriber.tagged':
      // Handle tag addition
      break;
    // Add more cases as needed
  }
  res.sendStatus(200);
});

Best Practices: Work Smarter, Not Harder

1. Cache frequently accessed data to reduce API calls.
2. Use batch operations when possible for better performance.
3. Implement exponential backoff for retries on failed requests.
4. Keep your local data model in sync with ConvertKit's structure.

Wrapping Up

And there you have it! You're now equipped to read and write data like a pro using the ConvertKit API. Remember, practice makes perfect, so don't be afraid to experiment and push the boundaries of what you can do.

Happy coding, and may your integrations be ever smooth and your data always in sync!