Webhooks e Callbacks

const response = await fetch('https://api.axon.com/v1/webhooks', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${process.env.AXON_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    url: 'https://your-app.com/webhooks/axon',
    events: [
      'payment.completed',
      'payment.failed',
      'token.created',
      'token.expired',
    ],
    description: 'Webhook principal de producao',
  }),
});

const webhook = await response.json();
// Guarde o webhook.secret para verificar assinaturas

const crypto = require('crypto');

function verifyWebhookSignature(payload, signature, secret) {
  const expectedSignature = crypto
    .createHmac('sha256', secret)
    .update(typeof payload === 'string' ? payload : JSON.stringify(payload))
    .digest('hex');

  return crypto.timingSafeEqual(
    Buffer.from(signature, 'hex'),
    Buffer.from(expectedSignature, 'hex')
  );
}

// No seu endpoint
app.post('/webhooks/axon', express.raw({ type: 'application/json' }), (req, res) => {
  const signature = req.headers['x-axon-signature'];
  const timestamp = req.headers['x-axon-timestamp'];

  // Verificar timestamp para prevenir replay attacks
  const now = Math.floor(Date.now() / 1000);
  if (Math.abs(now - parseInt(timestamp)) > 300) {
    return res.status(401).json({ error: 'Timestamp expired' });
  }

  // Verificar assinatura
  const signedPayload = `${timestamp}.${req.body}`;
  if (!verifyWebhookSignature(signedPayload, signature, process.env.WEBHOOK_SECRET)) {
    return res.status(401).json({ error: 'Invalid signature' });
  }

  const event = JSON.parse(req.body);
  // Processar evento...

  res.status(200).json({ received: true });
});

{
  "id": "evt_abc123def456",
  "type": "payment.completed",
  "created_at": "2024-01-15T10:30:00Z",
  "api_version": "2024-01-01",
  "data": {
    "object": {
      "id": "pay_xyz789",
      "amount": 150.00,
      "currency": "BRL",
      "status": "completed",
      "metadata": {
        "order_id": "order_123"
      }
    },
    "previous_attributes": {
      "status": "processing"
    }
  }
}