Webhooks

Mittis POSTs JSON events to your endpoint. Each request has an x-mittis-signature header in the form t=<unix>,v1=<hex>. The signature is an HMAC-SHA256 of {t}.{rawBody} using your endpoint secret. Reject anything older than five minutes.

Node · verify a signature

import { createHmac, timingSafeEqual } from 'node:crypto';

export function verify(secret, header, rawBody) {
  const { t, v1 } = Object.fromEntries(header.split(',').map(p => p.split('=')));
  if (Math.abs(Date.now() / 1000 - Number(t)) > 300) return false;
  const expected = createHmac('sha256', secret).update(`${t}.${rawBody}`).digest('hex');
  return timingSafeEqual(Buffer.from(expected), Buffer.from(v1));
}

Event types

SMSmessage.receivedA customer replied

SMSmessage.statusDelivery state changed

CALLcall.ringingInbound call started ringing

CALLcall.completedAnswered call ended

CALLcall.missedNobody answered

CALLcall.transcriptFinal transcript is ready

EMAILemail.deliveredAccepted by the recipient's server

EMAILemail.openedRecipient opened it

EMAILemail.bouncedHard or soft bounce

Build with Mittis.

Webhooks

Event types

Send your first message
in five minutes.

Build with Mittis.

Webhooks

Event types

Send your first messagein five minutes.

Send your first message
in five minutes.