lumbridge-code/docs/decisions/0002-usage-provenance.md

0002: Usage data always carries provenance

Status: accepted for the architecture phase.

Provider quotas and subscription windows do not share a stable universal API. Lumbridge therefore stores observations with their source and derives forecasts without overwriting the facts.

Allowed provenance values begin as provider-reported, harness-reported, locally measured, estimated, and unavailable. The UI may simplify these labels in compact views, but the detail view and export retain them.

Lumbridge will not scrape browser cookies, copy upstream OAuth tokens, or label a local estimate as an exact remaining subscription balance.