Trust → Integrity → Verify

Re-hash any snapshot.

Every snapshot Fonteum publishes ships with a SHA-256 attestation. Look up any attested snapshot by its numeric id and you'll get the full envelope: the upstream archive URL, the published content hash, the attested-at timestamp, and (when available) the cached mirror URL on Fonteum's 90-day rolling S3 cache. Re-hash the bytes yourself; the result MUST equal the published hash.

How the re-hash flow works

Look up the snapshot — GET /verify/<snapshot_id> returns the attestation envelope: content_hash,source_archive_url, cache_url (if mirrored), attested_at, and methodology_version.
Download the bytes — fetch source_archive_url from the upstream agency, OR cache_url from the Fonteum 90-day mirror if the upstream URL has rotated.
Re-hash — shasum -a 256 archive.csv. The result MUST equal content_hash. If it doesn't, the bytes were altered (or the source agency rotated their archive without publishing a new snapshot id) — the discrepancy is reportable to corrections@fonteum.com.

Methodology · Corrections log · Editorial policy

Trust → Integrity → Verify

Re-hash any snapshot.

How the re-hash flow works

Look up the snapshot — GET /verify/<snapshot_id> returns the attestation envelope: content_hash,source_archive_url, cache_url (if mirrored), attested_at, and methodology_version.
Download the bytes — fetch source_archive_url from the upstream agency, OR cache_url from the Fonteum 90-day mirror if the upstream URL has rotated.
Re-hash — shasum -a 256 archive.csv. The result MUST equal content_hash. If it doesn't, the bytes were altered (or the source agency rotated their archive without publishing a new snapshot id) — the discrepancy is reportable to corrections@fonteum.com.

Methodology · Corrections log · Editorial policy

Re-hash any snapshot.

How the re-hash flow works

Compliance posture

Re-hash any snapshot.

How the re-hash flow works

Compliance posture