Error Taxonomy

Uni-Xervo uses RuntimeError to separate config, load, API, and inference failures.

Variants

• Config(String)
• ProviderNotFound(String)
• CapabilityMismatch(String)
• Load(String)
• ApiError(String)
• InferenceError(String)
• RateLimited
• Unauthorized
• Timeout
• Unavailable

Retryability

RuntimeError::is_retryable() returns true for:

• RateLimited
• Timeout
• Unavailable

These are the only variants retried by instrumented wrappers when retry is configured.

Remote HTTP mapping

Remote providers map HTTP status to runtime errors:

• 429 -> RateLimited
• 401, 403 -> Unauthorized
• 5xx -> Unavailable
• Other non-2xx -> ApiError

Typical diagnosis workflow

1. Config: catalog/provider setup bug.
2. ProviderNotFound: provider not registered or not compiled.
3. CapabilityMismatch: requested typed handle does not match alias task/provider capability.
4. Load: provider initialization or model materialization failure.
5. ApiError/InferenceError: inspect provider response body and model input assumptions.