Outcome LedgerBi-Temporal Notarization & Zero-Hallucination Methodology
Every OL-YYYY-NNNNNN record in Outcome Ledger is ingested exclusively from official statutory endpoints, cryptographically hashed before parsing, and scheduled for longitudinal T+90, T+180, T+365, and T+1095 follow-up audits.
1. Statutory Public-Record Allowlist & Zero-PII Law
Only official government, regulatory, and municipal open endpoints (.gov, .mil, .edu, Legistar municipal APIs) are ingested. Unstructured strings pass through a deterministic PII redaction gate before persistence; no private natural-person records are collected.
2. SHA-256 Payload Hashing & Verbatim Substring Gate
Raw upstream bytes are hashed with SHA-256 at capture time and sealed into daily Zstandard (.tar.zst) cold-vault archives. Every record's verbatim_excerpt is verified byte-for-byte against the captured primary document.
3. Bi-Temporal Revisions & Link-Rot Detection
Upstream government servers frequently overwrite records in place or remove expired notices (HTTP 404). Our append-only revision ledger records both valid_from (statutory event date) and tx_recorded_at (ledger observation timestamp), preserving an unforkable audit trail when upstream URLs rot or silently change.