A settlement rail that pays for off-chain AI compute only when two independent proofs, of two different kinds, agree inside a single transaction: that the buyer really paid, and that the answer really came from the code they agreed to.
Live on Creditcoin CC3 testnet and Ethereum Sepolia. Source and full write-up on GitHub · Deck (PDF)
The buyer we built it for is someone like Amara, who runs risk at a small lender. Two thirds of her loan applicants have no credit file, so the only way to price them is to run a model over their transaction history. She has no GPUs, and she cannot hand borrower data to a company that might keep a copy. So today she does not do it, and the loans do not get made.
Her software locks payment on Ethereum and, in the same transaction, states which enclave build she is willing to accept. The requirement travels inside the payment.
The provider runs the model inside a sealed compartment on their server, which can prove which code is inside it and which not even the machine's owner can see into. It signs the result.
A contract on Creditcoin releases the money only if both proofs check out. If the answer came from different code than she named, it refuses and she keeps her money.
Amara would never see this page. She would use a client, or her own back-office software, calling the same contracts. This page is the audit tool, and it exists so that somebody who was not involved, her auditor, her regulator, a competitor, or you, can check any settlement afterwards without asking permission from anyone, including us.
Everything below is read live from Creditcoin in your browser, plus one signature checked against Google's published keys. There is no backend and no API key. The fields are prefilled with a real settlement; change them and check a different one.
It happened on Ethereum, which Creditcoin cannot see. The Attestcoin Protocol proves it, and the settlement contract records the proof as spent so the same payment cannot be settled twice.
The registry binds an enclave build to the key it signs with. The contract enforces the build the buyer named, not a list of its own, so changing what the buyer asked for changes the settlement rule with no redeploy and no admin key.
The chain cannot check a hardware certificate; it would cost more gas than any settlement is worth. So this page fetches the enclave's attestation and Google's live signing keys and checks the signature here, then confirms the image inside it is the build bound on chain.
Accepted pays the provider, rejected returns the buyer's claim, partial splits it. Whatever the verdict, the parts equal the amount locked on Ethereum and nothing is created that was not paid for.
The registry does not verify hardware attestation on chain, because no contract can afford to. It records the binding, a hash of the attestation and where to fetch it, and enforces the binding. The checking happens here, in your browser, where anyone can repeat it and disagree in public.
The rail is one-directional today. Attestcoin carries attested data into Creditcoin; carrying a settlement receipt back out needs writability, which is out of scope this season, so the buyer's refund is gated on elapsed time rather than on a receipt. That is the last trusted component and it is named rather than hidden.