Agent Contract Proof

{
  "protocolVersion": "1.0",
  "name": "Agent Contract Proof",
  "description": "Verify that a public agent or API endpoint matches its advertised payment and schema contract.",
  "url": "https://agent-contract-proof.mattskowronis.workers.dev/a2a",
  "preferredTransport": "JSONRPC",
  "additionalInterfaces": [
    {
      "url": "https://agent-contract-proof.mattskowronis.workers.dev/a2a",
      "transport": "JSONRPC"
    }
  ],
  "supportedInterfaces": [
    {
      "url": "https://agent-contract-proof.mattskowronis.workers.dev/a2a",
      "protocolBinding": "JSONRPC",
      "protocolVersion": "1.0"
    }
  ],
  "capabilities": {
    "streaming": false,
    "pushNotifications": false,
    "stateTransitionHistory": false
  },
  "provider": {
    "organization": "Skowron Works",
    "url": "https://skowronworks.com/agent-tools/agent-contract-proof/"
  },
  "version": "1.0.0",
  "documentationUrl": "https://skowronworks.com/agent-tools/agent-contract-proof/",
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "skills": [
    {
      "id": "verify_agent_contract",
      "name": "Verify Agent Contract",
      "description": "Compare an agent's advertised contract with its live x402 challenge and return deterministic proof.",
      "tags": [
        "x402",
        "agent-contract",
        "payment-proof",
        "schema-verification",
        "dependency-monitoring"
      ],
      "examples": [
        "Check whether this agent still charges one cent to the advertised wallet.",
        "Compare the current contract hash with the hash saved on the last successful run.",
        "Verify the advertised route, method, price, network, wallet, asset, and schemas before paying."
      ]
    }
  ],
  "securitySchemes": {
    "x402": {
      "type": "apiKey",
      "in": "header",
      "name": "PAYMENT-SIGNATURE",
      "description": "x402 exact scheme, $0.01 USDC on eip155:8453"
    }
  },
  "security": [
    {
      "x402": []
    }
  ],
  "protocol": "x402",
  "x402Version": 2,
  "environment": "production",
  "payment": {
    "method": "POST",
    "path": "/v1/verify",
    "scheme": "exact",
    "price": "$0.01",
    "network": "eip155:8453",
    "asset": "USDC",
    "payTo": "0x3a438B911B8E2995a9C855578F95B2889752498F"
  },
  "input_schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "url"
    ],
    "properties": {
      "url": {
        "type": "string",
        "maxLength": 2048,
        "description": "Public HTTP or HTTPS agent/API URL. An origin URL may be resolved through discovery metadata."
      },
      "method": {
        "type": "string",
        "enum": [
          "GET",
          "POST",
          "PUT",
          "PATCH",
          "DELETE"
        ],
        "description": "Optional method to probe. If omitted, the advertised method is used, then GET as a fallback."
      },
      "expected_hash": {
        "type": "string",
        "pattern": "^[a-fA-F0-9]{64}$",
        "description": "Optional previous contract_hash. A mismatch proves the public contract changed."
      }
    }
  },
  "output_schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "verdict",
      "target_url",
      "target_method",
      "target_status",
      "declared",
      "observed",
      "checks",
      "mismatches",
      "evidence_urls",
      "checked_at",
      "contract_hash",
      "service_version"
    ],
    "properties": {
      "verdict": {
        "type": "string",
        "enum": [
          "conforms",
          "mismatch",
          "unreachable",
          "insufficient_evidence"
        ]
      },
      "target_url": {
        "type": "string"
      },
      "target_method": {
        "type": "string",
        "enum": [
          "GET",
          "POST",
          "PUT",
          "PATCH",
          "DELETE"
        ]
      },
      "target_status": {
        "type": "string",
        "enum": [
          "verified",
          "unreachable",
          "blocked",
          "unsupported",
          "insufficient_evidence"
        ]
      },
      "declared": {
        "type": "object",
        "description": "Normalized public Agent Card or OpenAPI declaration."
      },
      "observed": {
        "type": "object",
        "description": "Normalized live HTTP/x402 challenge."
      },
      "checks": {
        "type": "array",
        "items": {
          "type": "object"
        }
      },
      "mismatches": {
        "type": "array",
        "items": {
          "type": "string"
        }
      },
      "evidence_urls": {
        "type": "array",
        "items": {
          "type": "string"
        }
      },
      "checked_at": {
        "type": "string"
      },
      "contract_hash": {
        "type": "string",
        "pattern": "^[a-f0-9]{64}$"
      },
      "service_version": {
        "type": "string"
      }
    }
  },
  "input_example": {
    "url": "https://source-claim-proof.mattskowronis.workers.dev"
  },
  "network": "eip155:8453",
  "listed_price": "$0.01"
}