Creating a Simple Webhook Listener Endpoint in Node.js Express

const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors'); // Required if your frontend is on a different origin

const app = express();
const PORT = process.env.PORT || 3000;

// Middleware
app.use(cors()); // Enable CORS for all routes (adjust as needed for security)
app.use(bodyParser.json()); // To parse JSON bodies
app.use(bodyParser.urlencoded({ extended: true })); // To parse URL-encoded bodies

// Webhook endpoint
app.post('/webhook/data', (req, res) => {
  console.log('Webhook received data!');
  console.log('Headers:', req.headers);
  console.log('Body:', req.body);

  // Example: Process the incoming data
  if (req.body && req.body.event === 'order.created') {
    console.log(`New order created: ${req.body.orderId} for customer ${req.body.customerEmail}`);
    // Here you would typically save to a database,
    // trigger other services, send notifications, etc.
  } else if (req.body) {
    console.log('Received generic webhook event:', req.body.event || 'unknown event');
  } else {
    console.log('Received webhook with no body.');
  }

  // Respond to the webhook sender to acknowledge receipt
  // A 200 OK status indicates successful receipt and processing.
  res.status(200).send('Webhook received successfully!');
});

// Optional: A simple GET route for health check or testing
app.get('/', (req, res) => {
  res.status(200).send('Webhook listener is running!');
});

// Start the server
app.listen(PORT, () => {
  console.log(`Webhook listener server running on http://localhost:${PORT}`);
  console.log('Listen for POST requests at /webhook/data');
});

// How to test (e.g., using curl):
// curl -X POST -H "Content-Type: application/json" \
//      -d '{"event": "order.created", "orderId": "12345", "customerEmail": "[email protected]", "items": [{"id": 1, "name": "itemA"}]}' \
//      http://localhost:3000/webhook/data