Endpoint
POST /x402/attest/digest?artifact=<text>
Unpaid requests receive a 402 quote. Paid requests carry x-agent-authority and
x-principal-challenge.
Reputation-priced
The price and the artifact ceiling come from the caller's published fidreon-trust/v1
score. An agent with no history is served a token-sized artifact at a low ceiling rather than
turned away. The basis is returned in x-fidreon-price-basis.
Settlement, stated plainly
This seller runs in sandbox settlement. No funds move, and its receipts record
amount_usd: 0 with settled: false so a sandbox transaction cannot inflate
a published score's volume factor.
Price bands
| Caller tier | Published score | Price | Artifact ceiling |
|---|---|---|---|
| trusted | 450 to 1000 | $0.005 | 65,536 bytes |
| established | 200 to 449 | $0.008 | 32,768 bytes |
| emerging | 50 to 199 | $0.010 | 8,192 bytes |
| unrated | 0 to 49 | $0.010 | 1,024 bytes |
Verification order
1. envelope signature, expiry, scope, spend cap (offline, ed25519) 2. principal registration in the FIDREON registry 3. revocation verdict from the registry (fail CLOSED) 4. principal challenge over a fresh nonce (fail CLOSED) 5. reputation band -> price and artifact ceiling 6. serve, sign the receipt, submit it to the registry