Your agent asks.
Pays $0.001.
Gets a verdict.

Rate card

Every endpoint answers unpaid requests with a 402 quote. Agents pay per call and get JSON back. Verdicts come stamped HOLD CAUTION AVOID — each one carrying an _evidence object with the checks performed, data sources, freshness, confidence and limitations. Read the full methodology before you pay for anything.

Every answer carries its evidence

A verdict that sounds certain is dangerous without its limits attached, and a stale "clean" result is worse than no result at all. So the evidence is part of the response — inside the signature, so it can't be stripped or edited in transit.

{
  "verdict": "caution",
  "_evidence": {
    "checksPerformed": ["Ownership and mint authority", "Proxy upgradeability",
                        "Holder concentration", "Transfer-restriction patterns"],
    "dataSources":     [{ "name": "Base mainnet RPC", "refresh": "per-request" }],
    "freshness":       { "basis": "live-chain", "maxUsefulAgeSeconds": 60,
                         "staleDataRisk": "A proxy can change its implementation
                                           after this check was performed." },
    "assurance":       { "level": "heuristic", "basis": "static analysis of contract
                                            state and holder distribution" },
    "semantics":       { "assuranceIsNotAProbability": "...NOT a calibrated probability...",
                         "signatureProvesIntegrityNotTruth": "...integrity is not truth..." },
    "humanApprovalRecommended": "unless_verdict_is_hold",
    "limitations": [
      "'caution' means a configured signal fired. It is NOT a finding of fraud,
       and 'hold' is NOT an endorsement or a recommendation to transact.",
      "Heuristic static analysis, not a security audit. A proxy contract can
       change its implementation after this check.",
      "Informational risk signal only; not regulated financial, legal or
       compliance advice."
    ]
  }
}

Deliberately not a score. Assurance is an ordinal label — deterministic, observed, exact-list-match, structural, heuristic — describing how the answer was produced. It is not a number, because a number would imply a calibration ChainVerdict has not performed. An IBAN checksum is deterministic because the arithmetic is certain; that still proves nothing about whether the account exists.

And a signature proves integrity, not truth. It shows this response came from ChainVerdict unaltered. A signed wrong answer is still wrong — and still signed. Both statements ship on every response and are documented at /v1/methodology, free to read so a buyer can audit how a verdict is produced before paying for one.

Call it in 30 seconds

Any x402 client works. With x402-fetch and a funded Base wallet:

import { wrapFetchWithPayment } from "x402-fetch";
const payFetch = wrapFetchWithPayment(fetch, account);
const res = await payFetch(
  "https://chainverdict.xyz/v1/token/verdict/0x4200000000000000000000000000000000000006"
);
console.log(await res.json()); // → verdict, score, reasons

Three services, one operator

ChainVerdict is one of three. All are payable per call over x402 with no account, all sign their responses, and all publish what their answers do not establish. Machine-readable manifest ↗

TradeRails — every endpoint trade.chainverdict.xyz

x402pulse — every endpoint pulse.chainverdict.xyz

33 paid endpoints across the three services (34 counting /v1/gs1/decode twice, once per method). Every one of them is published in the Coinbase x402 Bazaar discovery catalogue, and every price on this page is the price the live 402 quote returns — a test fails the build if those two ever disagree.

The archive

x402pulse has been probing third-party endpoints every ten minutes since 7 August 2026. Each day is reduced to a Merkle root, chained to the previous day, and timestamped into Bitcoin via OpenTimestamps.

Anyone can rebuild this software and start observing tomorrow. Nobody can produce a timestamp dated earlier than they created it. That is the difference between an archive and a claim — and it means the observation record can be checked without trusting the operator.

Check a receipt yourself

Paste any signed response into the verifier ↗. It checks the Ed25519 signature in your own browser against the published key and renders the evidence record. Nothing is sent anywhere — a verification tool you have to trust the server for is not a verification tool.

A valid signature proves a response came from the service unaltered. It does not prove the answer is correct. A signed wrong answer is still wrong, and still signed. That sentence ships inside every response and is meant literally.