Inspect an x402 endpoint without paying

$0.003 per call · failed calls are never charged · no account or API key needed

Decode any public x402 endpoint's 402 payment requirements without paying (v1 body or v2 header): USD price for native USDC, network, asset, recipient, scheme and timeout, plus a listing-quality score for https resource URL, atomic amount, facilitator minimum, description, Bazaar metadata and output schema. Never signs. Use before buying from an unfamiliar seller or to debug your own listing.

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

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/x402/check?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/x402/check?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",
  "status": 402,
  "paywalled": true,
  "x402Version": 2,
  "resource": {
    "url": "https://agent-data-tools.revmesh2074.workers.dev/btc-fees",
    "description": "Current Bitcoin network fee rates… Use before sending a Bitcoin transaction…",
    "mimeType": "application/json"
  },
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:8453",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "payTo": "0x…",
      "amountAtomic": "2000",
      "priceUsd": 0.002,
      "assetIsNativeUsdc": true,
      "maxTimeoutSeconds": 300
    }
  ],
  "checks": [
    {
      "check": "x402 payment requirements present",
      "pass": true
    }
  ],
  "score": 1
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is x402_check, and the first 25 successful calls are free:

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

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