mobile_call_ai_held
The receptionist may not call this customer yet (E2-R11): holds[] says why in the person's words - most often ai_consent_missing (no prior express written consent for marketing on the ledger; a teammate's review never counts), the calling window, or do-not-contact - with required_basis and window_opens_at.
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/mobile_call_ai_held",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}