internal_error
An exception no handler claimed. Answered by the outermost layer, so the CORS allow-list headers are added by hand for an admitted browser origin (without them the portal reports a transport failure, not the 500) together with X-Request-Id; the traceback is logged under that id.
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/internal_error",
"title": "…",
"status": 500,
"detail": "…",
"instance": "/v1/…"
}