Gateway Nanopayments Primer
Circle Developer Notes / 0.002400 USDCreceipt evidence
0xc6513e63...7c358d
accrued -> claimable on-chain
Circle Developer Notes
This receipt binds a source payment to the answer that used it; FeeRouter-routed receipts accrue into creator-claimable balances. The previous hash links it into the append-only attribution ledger.
answer context
How does SHA-256 evidence hashing ensure citation integrity in AI systems?
SHA-256 evidence hashing in AI citation systems ensures integrity by creating cryptographic proofs of content and payment authenticity. In the CitePay Markets implementation on Arc, every PAY decision generates an on-chain receipt with a SHA-256 evidence hash that binds the cited content to the payment transaction. This hash serves as immutable proof that: (1) the specific source content was used in the answer, (2) the creator received payment via Circle Gateway x402 settlement, and (3) the transaction is verifiable on-chain without requiring a trusted database. The evidence hash makes citation integrity enforceable—any modification to the source or payment record would invalidate the hash, creating a tamper-evident audit trail. Combined with on-chain settlement on Arc Testnet, this approach ensures creators can verify they were paid for their work and users can cryptographically confirm the sources backing an AI answer.
Open answer evidence