Scan Attestations

How it works

When Sigil Bot completes a scan, it produces a signed attestation before publishing the result. The attestation chain follows two established standards, with an optional third:

Attestation predicate

The in-toto predicate contains the complete scan result. Nothing is omitted — the attestation is a tamper-evident record of exactly what Sigil found.

{
  "scanner": {
    "uri": "https://github.com/NOMARJ/sigil",
    "version": "1.3.6",
    "phases": ["install_hooks", "code_patterns", "network_exfil", ...]
  },
  "scan": {
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "ecosystem": "npm",
    "package_name": "express",
    "package_version": "4.18.2",
    "verdict": "LOW_RISK",
    "risk_score": 0,
    "findings_count": 0,
    "files_scanned": 187,
    "duration_ms": 2340
  },
  "findings": [],
  "metadata": {
    "source": "npm-watcher",
    "bot_scan": true,
    "scanned_at": "2026-03-01T12:00:00Z",
    "content_hash_algorithm": "sha256",
    "content_hash": "a1b2c3d4..."
  }
}

Signing key

Sigil Bot signs attestations with an Ed25519 key. The public key and verification metadata are published as a well-known file:

curl https://sigilsec.ai/.well-known/sigil-verify.json

Verification steps

To verify a scan attestation manually:

API endpoints

Fetch attestation

curl https://sigilsec.ai/api/v1/attestation/{scan_id}

Returns the DSSE envelope as application/vnd.in-toto+json. Responds 404 if the scan has no attestation.

Verify attestation

curl -X POST https://sigilsec.ai/api/v1/verify \
  -H 'Content-Type: application/json' \
  -d '{"scan_id": "{scan_id}"}'

Server-side verification. POST a JSON body with either scan_id or content_digest. Returns whether the attestation signature is valid, the signing key ID, and the timestamp. log_entry is null unless Rekor submission is enabled.

{
  "verified": true,
  "scan_id": "550e8400-e29b-41d4-a716-446655440000",
  "signed_at": "2026-03-01T12:00:00Z",
  "key_id": "sha256:sigil-bot-signing-key-2026",
  "log_entry": null
}

On scan reports

When a scan has a signed attestation, the report page shows a green SIGNED badge next to the scan date. If the attestation has a transparency log entry, a “(log)” link takes you to the Sigstore Rekor search page.

The attestation is also included in the page's JSON-LD structured data as a DigitalDocument schema, making it discoverable by AI agents and search engines.

See also

• •Sigil Bot — the autonomous scanner that produces signed attestations
• •API Reference — all scan API endpoints
• •Scan Database — browse signed scan results
• •in-toto.io — the attestation framework specification