Webhook-Driven Email Automation: Events, Decoupling, and Reliable Delivery

Webhook-Driven Email Automation: Events, Decoupling, and Reliable Delivery

Hardcoding send-email logic inside business code is one of the most common forms of technical debt. A webhook plus queue architecture lets you separate "what the business did" from "what email to send."

The architecture

Business system fires an event → message queue or direct POST → email service decides what to send based on event type → delivered to user.

User completes payment
  └─ POST /webhooks/payment  { event: "payment.completed", orderId: "123" }
       └─ Email service looks up template, sends order confirmation

Receiving Rovela webhooks

Rovela itself fires webhooks when an email is delivered, opened, clicked, or bounced. This lets you build automated follow-ups:

// User clicked a link in an email
app.post('/webhooks/rovela', (req, res) => {
  const { event, data } = req.body;
  if (event === 'email.clicked') {
    salesQueue.add('follow-up', { userId: data.metadata.userId });
  }
  res.sendStatus(200);
});

Verifying the signature

Rovela webhook requests include an HMAC signature header. Always verify it:

const crypto = require('crypto');
function verifySignature(payload, signature, secret) {
  const expected = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expected)
  );
}

Idempotency

Webhooks can fire more than once. Deduplicate with the event ID:

const exists = await redis.set(
  `webhook:${event.id}`, '1', 'NX', 'EX', 86400
);
if (!exists) return res.sendStatus(200); // already processed

Rovela Automations

If you'd rather not write this code, Rovela Automations lets you configure trigger conditions and email sequences in the dashboard — useful for marketing workflows. Transactional emails (order confirmation, password reset) usually belong in the API for more control.