Accept fast. Send async. Tell the truth about what happened.

import { MailHaap } from "@mailhaap/node";

const mh = new MailHaap(process.env.MAILHAAP_API_KEY);

const { id } = await mh.emails.send({
  from: "Kadıköy Property <[email protected]>",
  to: "[email protected]",
  subject: "Order A-1043 confirmed",
  html: "<p>Hello {{ first_name }}</p>",
  tags: [{ name: "category", value: "order_confirmation" }],
});

console.log(id); // msg_01J8XQ7M2K9PQRSTUV

import { verifyWebhook } from "@mailhaap/node";

app.post("/hooks/mailhaap", async (req, res) => {
  // Throws when the signature is wrong or |now - t| > 300s.
  const event = verifyWebhook({
    payload: req.rawBody,
    signature: req.headers["mailhaap-signature"],
    secret: process.env.MAILHAAP_WEBHOOK_SECRET,
  });

  // Event ids are stable across retries — consumers must be idempotent.
  if (await alreadyHandled(event.id)) return res.sendStatus(200);

  switch (event.type) {
    case "email.bounced":
      await suppress(event.data.to, event.data.bounce.class);
      break;
    case "email.complained":
      await unsubscribe(event.data.to);
      break;
  }

  res.sendStatus(200);
});