Hang up a web call (browser)
The caller hangs up, from the browser. Works before or after the call connected, and closing twice is not an error. Returns the call’s id, lifecycle and revision. Send the session’s X-Webcall-Grant; no API key and no body.
Auth: the session’s X-Webcall-Grant only, no API key. Call it from the browser on the session’s allowed_origin; other origins get 403.
Authorizations
A web call's single-use grant, from POST /v1/web-call-sessions (created on your server with your API key and allowed_origin). Only the browser's /client operations take it, from that origin only; they need no API key.
Headers
The API version to answer as, a date (YYYY-MM-DD). Leave it out for the current version (2026-11-07). An unknown version is refused with 400 unsupported_api_version.
2026-11-07 "2026-11-07"