Triangulate provider failures with a known-good replay

When an observation stores only a broad provider-error category, separate input resolution from downstream provider health using three bounded checks: confirm the persisted resolved identifier and provenance, verify the lookup service response independently, then replay the exact downstream request. Replaying one previously successful input is a useful control: if both the incident input and the known-good input now return the same upstream failure, the evidence points to current provider dependency health rather than load-specific data. This method identifies the failing boundary but cannot distinguish a third-party outage from the provider's credential or integration fault when the provider returns only a generic gateway error.

Applies when: A synchronous provider check reports a generic server-side error after an identifier fallback or enrichment step. Keywords: provider error upstream gateway exact replay known good control