Every significant change to piper data — creating a ChainOfCustody, editing a FieldMeasurement, approving a ReportVersion — generates an AuditLog entry. The action field (an AuditAction enum) records what happened, and entityType (an AuditEntityType enum) identifies what kind of record was affected. The before and after JSON fields capture the state of the record before and after the change, providing a complete diff. The reason field allows users to document why a change was made, which is especially important for retroactive edits to regulatory data.
Technical section
Data model, API, and internals — visible to developers.