{"attestation_date":"2026-09-13","merkle_root":"9da3efb6ebb2e741482eb36b5262c476237fdbfae0a6573739bcc56d052bbfa6","total_sources":36631,"max_source_id":69050,"signature":"3554d3e011da4cb9d8a1b5cee3b66b9757eeb3dc9b3fe1f08c0e3cadeec69403","signature_algorithm":"hmac-sha256(date|root|total_sources)","external_publish_url":null,"computed_at":"2026-09-13T22:13:15.493Z","witnesses":[],"verifyHowto":{"summary":"Rebuild the Merkle tree from /source/:id/receipt.json hashes for id in [1..max_source_id] and compare to merkle_root.","leafOrder":"ascending by source.id, content_hash strings as-is (lowercase hex)","hashFunction":"sha256","interiorNodeFormula":"sha256(left_hex || right_hex)","oddLevelHandling":"duplicate the last leaf (Bitcoin convention)"}}