Paddle Mailchimp Integration

paddleMailChimp.js

// We use this for the Mailchimp API calls
const https = require('https');

// Input a Mailchimp API Key here; we just use Basic Auth for Server to Server communication
// https://mailchimp.com/help/about-api-keys/
const mailchimpApiKey = process.env.MAILCHIMP_API_KEY;

// Input your Mailchimp domain controller here 
// When logged into Mailchimp, first part of URL in your browser, eg us20.admin.mailchimp.com is us20
const domainController = process.env.MAILCHIMP_DC;

// This maps the purchased Paddle Product IDs to Mailchimp audiences/lists
// https://mailchimp.com/help/find-audience-id/
const productToListMapping = {
    540922: '0f8ffd1063', // Paddle product ID 540922 mapped to the Mailchimp List/Audience ID
    540923: '0f8ffd1063' // Paddle product ID 540923 mapped to the Mailchimp List/Audience ID
};

// This code is written as an AWS Node Lambda, so that the webhook is sent to AWS API Gateway and "ingested" by this Lambda script,
// extracting the webhook data and then calling the Mailchimp API
exports.handler = async (event) => {
    // The data sent from Paddle; Paddle sends it as content type application/x-www-form-urlencoded
    // This is for an AWS Lambda, but getting this data from the HTTP POST will differ based on environment
    const webhookBody = event.data;

    return new Promise((resolve, reject) => {
        // See if we have a Mailchimp audience/list for that product
        let listId = productToListMapping[webhookBody.product_id];

        if (!listId) {
            reject('Product ID not supported');
        }

        // Now we can perform different actions based on certain Paddle alerts
        // For now, just add a Mailchimp contact for a payment success
        switch (webhookBody.alert_name) {
            case 'payment_succeeded':
                processMailchimp(webhookBody, listId).then(data => {
                    console.log(data);
                    resolve(JSON.parse(data));
                }, function(error) {
                    reject(JSON.parse(error.message))
                });
                break;
            default:
                reject('Webhook type not supported');
                break;
        }
    });
};

function processMailchimp(webhookBody, listId) {
    return new Promise((resolve, reject) => {
        const options = {
            host: domainController + '.api.mailchimp.com',
            port: 443,
            path: '/3.0/lists/' + listId + '/members',
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Basic ' + new Buffer.from('anystring:' + mailchimpApiKey).toString('base64')
            }
        };

        const req = https.request(options, (res) => {
            res.setEncoding('utf8');
            let returnBody = '';

            res.on('data', function (chunk) {
                returnBody += chunk;
            });

            res.on('end', function() {
                resolve(returnBody);
            });
        });

        req.on('error', (e) => {
            reject(e.message);
        });

        let data = JSON.stringify({"email_address": webhookBody.email, "status": "subscribed"});
        req.write(data);
        req.end();
    });
}