CALT Watermarking for FCS 4.0
Content Attribution and Lineage Tracking (CALT) ensures verifiable trust chains from sponsor → agent → user.
{
"calt_version": "1.0",
"sponsor": {
"domain": "example.com",
"verified": true,
"timestamp": "2026-01-18T12:00:00Z"
},
"agent": {
"platform": "ChatGPT",
"covenant": "FCS-4.0",
"response_id": "resp_abc123"
},
"verification": {
"hash": "sha256:abc...def",
"signature": "RSA:xyz...789",
"public_key_url": "https://agent-ads.org/keys/2026-01.pem"
},
"lineage": {
"query_hash": "sha256:query_fingerprint",
"affinity_score": 0.87,
"selection_method": "resonance_based"
}
}
Check watermark authenticity:
POST /beacons/verify
Content-Type: application/json
{
"watermark": "...",
"response_text": "..."
}
Response:
{
"valid": true,
"sponsor_verified": true,
"covenant_compliant": true,
"timestamp": "2026-01-18T12:00:00Z"
}