live_call_session_conflict
This code is raised on a non-customer surface (the /internal voice-runtime audience or telephony provider callbacks). It is excluded from the customer OpenAPI document and is registered here so an operator reading a log line has one place to look.
The token redeemed, but its pre-minted call identity could not be bound one-to-one to tenant-owned live-session state. The runtime refuses rather than start a conversation that a future carrier executor could attach ambiguously.
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/live_call_session_conflict",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}