mobile_metrics_window_invalid
The receptionist-metrics end must be strictly after start; the window is half-open [start, end).
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_metrics_window_invalid",
"title": "…",
"status": 400,
"detail": "…",
"instance": "/v1/…"
}