Errors and routing evidence

Errors

OpenAI-compatible failures include an error object and Problem Details fields such as type, title, status, and detail. A correlated request can include trace.request_id. Anthropic request validation returns an Anthropic-style error object.

Common statuses include 400 for invalid input, 401 for a missing or invalid key, 402 for payment requirements, 403 for forbidden access, 429 for rate limits, and 5xx for temporary service or upstream failures. Server-side details are deliberately masked. Retry only transient 429, 502, 503, and 504 responses, using bounded exponential backoff.

Routing evidence

Completion responses can expose:

• x-strix-lane — selected lane.
• x-strix-reason and x-strix-reasons — routing rationale summaries.
• x-strix-tier — selected service tier.
• x-strix-client — detected client when available.
• x-strix-request-id — request correlation ID.
• x-strix-filter, x-strix-providers, and x-strix-saved-* — filtering and savings evidence when available.
• x-strix-tokens-spent and x-strix-tokens-balance — token accounting when available.

Treat headers as optional evidence: log only the fields you need and never log authorization headers. Capture x-strix-request-id when reporting a failed request.