Webhook Setup

import express from 'express';
import { createHash } from 'node:crypto';

const app = express();

app.use(express.json());

app.post('/webhooks/killb', async (req, res) => {
  try {
    // 1. Verify signature
    const signature = req.headers['x-signature-sha256'];
    
    const expectedSignature = createHash('sha256')
      .update(`${JSON.stringify(req.body)}_${process.env.WEBHOOK_SECRET}`)
      .digest('hex');
    
    if (signature !== expectedSignature) {
      console.error('Invalid signature');
      return res.status(401).json({ error: 'Invalid signature' });
    }
    
    // 2. Acknowledge immediately
    res.status(200).json({ received: true });
    
    // 3. Process asynchronously
    processWebhookAsync(req.body).catch(console.error);
    
  } catch (error) {
    console.error('Webhook error:', error);
    res.status(500).json({ error: 'Processing failed' });
  }
});

const processWebhookAsync = async (event) => {
  console.log('Processing event:', event.event);
  
  switch(event.event) {
    case 'ramp.completed':
      await handleRampCompleted(event.data);
      break;
    case 'ramp.failed':
      await handleRampFailed(event.data);
      break;
    case 'user.kyc_approved':
      await handleKYCApproved(event.data);
      break;
  }
};

app.listen(3000);