llm_chain_unresolvable
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): no link in the agent's LLM routing chain is reachable from this deployment, so the session would connect to a pipeline with no model. A deployment fault, not the caller's.
§9.9 · Non-customer surfaces
No link in the agent's LLM routing chain is reachable from this deployment.
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/llm_chain_unresolvable",
"title": "…",
"status": 503,
"detail": "…",
"instance": "/v1/…"
}