inbound_voice_callbacks_unavailable
The signed inbound-Voice callback plane is not fully composed: it needs the credential vault, stable public base URL, session-token signing plane, LLM catalog, and Media Streams URL before a customer can copy a webhook URL.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/inbound_voice_callbacks_unavailable",
"title": "…",
"status": 503,
"detail": "…",
"instance": "/v1/…"
}