Error Reference

Status	Typical meaning
400	Invalid JSON, bounds, generation options, alert payload, workspace, proposal input, or missing confirmation.
401	Missing or incorrect API key or alert-source credential.
404	Unknown model, Run, alert source, incident, event, job, or consumed/expired/missing pending change.
409	Stale workspace, appeared create target, or apply conflict.
502	Upstream generation or validated simulation failure.
503	Generation slot, alert persistence, or an optional persisted endpoint is unavailable.

Native endpoints return {"error":{"message":"..."}}. OpenAI-compatible endpoints return an OpenAI-shaped error with message, type, param, and code. Treat error text as diagnostic data, not a stable programmatic contract; use HTTP status and documented codes.