voicemail_message_uncomposable
The agent carries a voicemail_config that composes no message (ADR-0023). A drop is a regulated artificial-voice call and is composed from the AI-disclosure opener, the configured body, and a platform opt-out closing; errors[] names the element that refuses. Also raised at campaign launch when the pinned agent version composes nothing.
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/voicemail_message_uncomposable",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}