call.started

Fires when an inbound or outbound call is initiated and the call leg enters the platform.

2026-06-27

Status: This event will start emitting once gateway-go upstream signals land. The contract documented here is stable.

call.started fires as soon as a call leg is registered in the platform, before any ringing or answer occurs. It is routed per-number via voice_callback_url / events_url and is not subscribable as a workspace webhook; configure it on the Routing tab for the relevant number.

{
  "kind": "call.started",
  "event_id": "01900000-0000-7000-8000-000000000001",
  "workspace_id": "01900000-0000-7000-8000-000000000002",
  "occurred_at": "2026-06-27T10:00:00.000Z",
  "data": {
    "call_id": "01900000-0000-7000-8000-000000000003",
    "direction": "inbound",
    "from": "+254700000001",
    "to": "+254700000002",
    "number_id": "01900000-0000-7000-8000-000000000004",
    "status": "started"
  }
}

Every webhook delivery includes the following request headers:

Header	Description
`X-Sautikit-Signature`	HMAC-SHA256 of the raw body, hex-encoded. Verify with your subscription secret.
`X-Sautikit-Idempotency-Key`	Unique delivery ID for deduplication.
`X-Sautikit-Event`	Literal event kind: `call.started`.

At-least-once: The dispatcher may deliver the same event more than once. Deduplicate using event_id or the X-Sautikit-Idempotency-Key header.
Retry schedule: Up to 5 attempts with exponential backoff (1-2-4-8-16 seconds). After exhausting attempts the delivery row moves to dead_letter.
Timeout: Your endpoint must respond within 10 seconds. A non-2xx response or timeout counts as a failed attempt.

import { createHmac } from "node:crypto";
 
export async function POST(req) {
  const sig = req.headers["x-sautikit-signature"];
  const body = await req.text();
  const expected = createHmac("sha256", process.env.WEBHOOK_SECRET)
    .update(body)
    .digest("hex");
  if (sig !== expected) return new Response("Forbidden", { status: 403 });
 
  const event = JSON.parse(body);
  if (event.kind === "call.started") {
    const { call_id, direction, from, to } = event.data;
    console.log(`Call ${call_id} started: ${direction} ${from} -> ${to}`);
  }
  return new Response("OK", { status: 200 });
}

Configure voice_callback_url / events_url on the Numbers Routing tab.
See Webhook concepts for signature verification details.
Monitor deliveries via GET /v1/webhooks/{id}/deliveries.

{
  "kind": "call.started",
  "event_id": "01900000-0000-7000-8000-000000000001",
  "workspace_id": "01900000-0000-7000-8000-000000000002",
  "occurred_at": "2026-06-27T10:00:00.000Z",
  "data": {
    "call_id": "01900000-0000-7000-8000-000000000003",
    "direction": "inbound",
    "from": "+254700000001",
    "to": "+254700000002",
    "number_id": "01900000-0000-7000-8000-000000000004",
    "status": "started"
  }
}

Header

Description

X-Sautikit-Signature

HMAC-SHA256 of the raw body, hex-encoded. Verify with your subscription secret.

X-Sautikit-Idempotency-Key

Unique delivery ID for deduplication.

X-Sautikit-Event

Literal event kind: call.started.

At-least-once: The dispatcher may deliver the same event more than once. Deduplicate using event_id or the X-Sautikit-Idempotency-Key header.

Retry schedule: Up to 5 attempts with exponential backoff (1-2-4-8-16 seconds). After exhausting attempts the delivery row moves to dead_letter.

Timeout: Your endpoint must respond within 10 seconds. A non-2xx response or timeout counts as a failed attempt.

import { createHmac } from "node:crypto";
 
export async function POST(req) {
  const sig = req.headers["x-sautikit-signature"];
  const body = await req.text();
  const expected = createHmac("sha256", process.env.WEBHOOK_SECRET)
    .update(body)
    .digest("hex");
  if (sig !== expected) return new Response("Forbidden", { status: 403 });
 
  const event = JSON.parse(body);
  if (event.kind === "call.started") {
    const { call_id, direction, from, to } = event.data;
    console.log(`Call ${call_id} started: ${direction} ${from} -> ${to}`);
  }
  return new Response("OK", { status: 200 });
}