---
title: "Initiate outbound call"
method: POST
path: "/v1/whatsapp/calls"
tags: ["WhatsApp Calling"]
---

# Initiate outbound call

`POST /v1/whatsapp/calls`

Initiates an outbound Business-Initiated Call. The Telnyx-side SIP
leg is originated server-side (Option B: SIP-first). Telnyx INVITEs
Meta directly over TLS:5061 with the SIP digest credentials we
captured at calling-enablement time). No client-side SDP is
required; pass only `accountId` and `to`.

To send the consumer the call-consent prompt instead of placing a
call, pass `action: "send_call_permission_request"` (+ optional
`bodyText`). The consumer must tap Allow in WhatsApp before
`start_call` is permitted; Meta limits the prompt to 1 per consumer
per 24h (2 per 7 days) and requires an open 24h service window.

**Idempotency:** send an `Idempotency-Key` header to make retries
safe; same key + same body replays the original response instead of
dialing (and billing) a second call.

## Headers

- `Idempotency-Key` string

## Request body

- object
  - `accountId` string, required
  - `to` string, required — Consumer wa_id (E.164, leading + optional)
  - `action` 'send_call_permission_request' — Omit to place a call. Set to send the consent prompt instead.
  - `bodyText` string — Body text shown with the consent prompt (send_call_permission_request only).
  - `forwardTo` string — Per-call destination override. Same accepted shape as the number's stored forwardTo (tel:+E164, sip:..., wss://...).
  - `recordOverride` boolean
  - `biz_opaque_callback_data` string — Accepted for forward compatibility. Not currently echoed back in webhook payloads (SIP-first flow does not pass through Meta's Graph API where Meta would echo this).

## Response `200`

Call originated; lifecycle continues asynchronously via webhooks.

- object
  - `success` boolean
  - `callId` string — Internal Call doc ID
  - `telnyxCallControlId` string — Telnyx call_control_id of the outbound leg
  - `status` 'dialing'
  - `direction` 'outbound'
  - `to` string
  - `forwardTo` string, nullable
  - `recordingEnabled` boolean

## Other responses

- `401` — Unauthorized
- `409` — No active call permission — send a permission request first.
- `422` — Calling not enabled, BIC country blocked, or missing Meta SIP credentials
- `502` — Telnyx-side originate failed; the Call doc has been marked failed.

---

[API](https://skmtc.net/zernio/apis/zernio-api.md) · [All operations](https://skmtc.net/zernio/apis/zernio-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/zernio/zernio-api/revisions/15e893e69e8c/schema)