Webhooks Setup

import express from 'express';
import crypto from 'crypto';

const app = express();
app.use(express.json());

const WEBHOOK_SECRET = process.env.FINALTX_WEBHOOK_SECRET;

app.post('/webhooks/finaltx', (req, res) => {
  // Handle verification challenge
  if (req.body.type === 'finaltx.webhook.verify') {
    return res.json({ challenge: req.body.challenge });
  }

  // Verify signature (recommended)
  const signature = req.headers['x-finaltx-signature'];
  const timestamp = req.headers['x-finaltx-timestamp'];
  const payload = `${timestamp}.${JSON.stringify(req.body)}`;
  const expected = crypto
    .createHmac('sha256', WEBHOOK_SECRET)
    .update(payload)
    .digest('hex');
  
  if (signature !== expected) {
    return res.status(401).json({ error: 'Invalid signature' });
  }

  // Process event
  const event = req.body;
  switch (event.type) {
    case 'contract.funded':
      console.log('Contract funded:', event.data.contract_id);
      break;
    case 'contract.released':
      console.log('Payment released to seller');
      break;
    // ... handle other events
  }

  res.json({ received: true });
});