Tool detail

verify

Probes a live agent/API URL and compares it against its advertised x402 contract, returning deterministic proof of match or drift.

Categories: API testing

Use when

verify a public API's live behavior still matches its advertised contract
prove a contract changed since a previously recorded hash

Not for

not a general uptime or liveness check (contract-comparison only)

Inputs

POST JSON body: url (string, required); method (enum GET|POST|PUT|PATCH|DELETE, optional); expected_hash (64-char hex, optional)

Admitted input schema

{
  "type": "object",
  "properties": {
    "expected_hash": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "pattern": "^[a-fA-F0-9]{64}$",
      "description": "Optional previous contract_hash. A mismatch proves the public contract changed."
    },
    "method": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "enum": [
        "GET",
        "POST",
        "PUT",
        "PATCH",
        "DELETE"
      ],
      "description": "Optional method to probe. If omitted, the advertised method is used, then GET as a fallback."
    },
    "url": {
      "type": "string",
      "minLength": 0,
      "maxLength": 2048,
      "description": "Public HTTP or HTTPS agent/API URL. An origin URL may be resolved through discovery metadata."
    }
  },
  "required": [
    "url"
  ],
  "additionalProperties": false
}

Endpoint

Method: POST
URL: https://agent-contract-proof.mattskowronis.workers.dev/v1/verify

Payment

Protocol: x402
Listed price: 0.01 USDC per call on Base
Payment method: exact
Network: eip155:8453
Asset: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Listed terms are catalog metadata. The caller supplies inputs and calls the tool outside Onelayer. If payment is required, the caller uses a compatible wallet to pay.

Source

Directory: Coinbase x402 Bazaar
Record: POST https://agent-contract-proof.mattskowronis.workers.dev/v1/verify
Retrieved: 2026-09-30T20:37:07.382Z
Catalog file SHA-256: 6837ccddf886f0007cf3727ea9d27faaa5047b51b4f425345c554ce1c271a524
Catalog built: 2026-09-30T22:31:58.034Z