v2
latestOpenAPI 3.1.02026-08-075421692.0 MBInitiate outbound call
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
Optional client-generated unique key (e.g. a UUID) that makes retries safe. Same key + same body replays the original response; same key + different body → 422; key still processing → 409.
Request body
Response
Call originated; lifecycle continues asynchronously via webhooks.