voice_profile_missing
This code is registered on two surfaces. The two entries are the same rule enforced in two places, so the meaning below is quoted per surface.
§9.6 · Calls, analytics, billing, and exports
Promoted from §9.9 (2026-08-11): the pinned agent version carries no voice, so there is nothing to speak with. Raised by POST /v1/agents/{id}/voice-session before any socket opens; §9.9 keeps the identical code for the runtime's own bootstrap. Answering it in HTTP is the point - the alternative is a WSS 1008 with no body, which tells the operator only that "it didn't work".
§9.9 · Non-customer surfaces
The pinned agent version carries no voice.
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/voice_profile_missing",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}