x402 seller audit API: vet terms, payTo and domain before paying

$0.01 per call · failed calls are never charged · no account or API key needed

Audit an x402 seller before an agent buys from it: decodes the endpoint's 402 terms without paying, OFAC-screens each payTo address, reads its account type and nonce on the payment network, checks the seller domain's age and trust flags, and flags non-USDC assets and high prices. One block, review or pass verdict with reasons. Never signs. Screening aid, not legal advice. Use before the first payment to an unfamiliar x402 seller.

When to use it

Run it free (25 free calls) Buy credits by card (from $5) Example result (JSON)

Try it with your own inputs

Absolute public https URL of the paid endpoint, with any query it needs

Uses one of your 25 free calls. Nothing is charged, and a call that fails is not counted.

Inputs

NameTypeDescription
url (required)stringAbsolute public https URL of the paid endpoint, with any query it needs

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://agent-data-tools.revmesh2074.workers.dev/check/x402-seller?url=https%3A%2F%2Fagent-data-tools.revmesh2074.workers.dev%2Fbtc-fees"

Or one of your 25 free calls, no key:

curl "https://agent-data-tools.revmesh2074.workers.dev/check/x402-seller?url=https%3A%2F%2Fagent-data-tools.revmesh2074.workers.dev%2Fbtc-fees&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum, Monad, World Chain or Tempo) and retries.

Example result

{
  "url": "https://agent-data-tools.revmesh2074.workers.dev/btc-fees",
  "verdict": "pass",
  "reasons": [],
  "terms": {
    "paywalled": true,
    "x402Version": 2,
    "score": 1,
    "accepts": [
      {
        "network": "eip155:8453",
        "payTo": "0x2074c40346ae2a90e0e4a391bcee6f16bf5277f5",
        "priceUsd": 0.002,
        "assetIsNativeUsdc": true
      }
    ]
  },
  "payees": [
    {
      "payTo": "0x2074c40346ae2a90e0e4a391bcee6f16bf5277f5",
      "network": "eip155:8453",
      "sanctioned": false,
      "sanctionMatches": [],
      "accountType": "eoa-delegated",
      "accountNonce": 1
    }
  ],
  "domain": {
    "name": "agent-data-tools.revmesh2074.workers.dev",
    "trust": "medium",
    "ageDays": 2812,
    "registeredAt": "2019-02-08T20:36:47.904Z",
    "flags": [
      {
        "level": "medium",
        "code": "few_nameservers",
        "message": "Fewer than two nameservers."
      }
    ]
  },
  "sanctionsListDate": "2026-10-17T20:15:00.000Z",
  "limitations": [],
  "note": "Screening aid only: confirm any sanctions match against the official OFAC record; a pass is not a guarantee the seller delivers."
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is check_x402_seller, and the first 25 successful calls are free:

https://agent-data-tools.revmesh2074.workers.dev/mcp

Questions

Does it pay or sign anything?

No. It reads the endpoint's unpaid 402 answer and public chain and registration data.

Does a pass mean the seller delivers?

No. It is a screening aid on who gets paid and on what terms, not a delivery guarantee.

How do I pay?

Each successful call costs $0.01; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $5) or per call in USDC over x402 or MPP. No account or API key is needed.

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