Audit trail and verification

Every decision, by the agent or by a person overriding it, becomes a decision record: a JSON document with the submission, the contributor, the round, the flags, the model's output, the rule that decided and the amount.

How a record is sealedCopy Anchor Link

1. The record is serialized as canonical JSON: keys sorted at every level, no whitespace, amounts as decimal strings of USDC base units (6 decimals).
2. Its decisionHash is keccak256 of those UTF-8 bytes.
3. The agent's wallet signs the hash (EIP-191 over the raw 32 bytes). The agent is a Circle smart-contract wallet, so the signature is checked with ERC-1271 isValidSignature on Arc.
4. Each payout on-chain carries a decisionHash of its own: keccak256 of the sorted hashes of the records it pays, concatenated. The PayoutExecuted event records it next to the amount and the recipient.

Verify in the browserCopy Anchor Link

Open a program's public audit page (/p/program-name) and choose Verify next to any decision. The page checks the hash, that the record was published, the signature, the payout it belongs to, and the PayoutExecuted event on Arc.

Verify it yourselfCopy Anchor Link

The public API returns the exact bytes that were hashed, with the signature and signer as headers:

curl -i https://<app>/api/public/decisions/<decisionHash>
# X-Decision-Signature: 0x…
# X-Decision-Signer: 0x74a6…78a1

Then, with viem:

import { createPublicClient, http, keccak256, toBytes, concat, parseEventLogs, parseAbi } from "viem";

const res = await fetch(`https://<app>/api/public/decisions/${hash}`);
const body = await res.text();

// 1. The record hashes to the decision hash.
console.log(keccak256(toBytes(body)) === hash);

// 2. The agent signed it. verifyMessage handles both EOAs and ERC-1271 smart-contract wallets.
const client = createPublicClient({ transport: http("https://rpc.testnet.arc.io") });
console.log(
  await client.verifyMessage({
    address: res.headers.get("x-decision-signer") as `0x${string}`,
    message: { raw: hash },
    signature: res.headers.get("x-decision-signature") as `0x${string}`,
  }),
);

// 3. The payout commits to it. `recordHashes` are the decision hashes listed for that payout on the audit page.
const payoutHash = keccak256(concat([...recordHashes].map((h) => h.toLowerCase() as `0x${string}`).sort()));

// 4. And the payout happened on Arc with that hash.
const receipt = await client.getTransactionReceipt({ hash: txHash });
const [event] = parseEventLogs({
  abi: parseAbi([
    "event PayoutExecuted(bytes32 indexed roundId, bytes32 indexed payoutId, address indexed to, uint256 amount, bytes32 decisionHash)",
  ]),
  logs: receipt.logs,
}).filter((l) => l.args.decisionHash === payoutHash);
console.log(event?.args.to, event?.args.amount);

What's in the audit logCopy Anchor Link

The owner's Audit log lists every event in the program: submissions, decisions, overrides, vault deposits and limit changes, round proposals, approvals and payouts, with transactions linked to the explorer. It can be exported as CSV. The table is append-only at the database level: updates and deletes are blocked by triggers.