Card snapshot

This is a frozen copy of the agent's agent-card.json as we observed it at the timestamp above. We capture a new snapshot every time the card's content hash changes. Useful for: forensic drift analysis, verifying downstream callers see the right version, reproducing routing decisions made historically.

{
  "protocolVersion": "1.0",
  "name": "Live Listing Proof",
  "description": "Verify a public product, classified, marketplace or auction listing immediately before an agent relies on or recommends it. Returns source-supported listing facts when retrievable, and explicit removed, blocked, unreachable, unsupported or insufficient-evidence states instead of inventing facts.",
  "url": "https://live-listing-proof.mattskowronis.workers.dev/a2a",
  "preferredTransport": "JSONRPC",
  "additionalInterfaces": [
    {
      "url": "https://live-listing-proof.mattskowronis.workers.dev/a2a",
      "transport": "JSONRPC"
    },
    {
      "url": "https://live-listing-proof.mattskowronis.workers.dev/v1/verify",
      "transport": "HTTP+JSON"
    }
  ],
  "supportedInterfaces": [
    {
      "url": "https://live-listing-proof.mattskowronis.workers.dev/a2a",
      "protocolBinding": "JSONRPC",
      "protocolVersion": "1.0"
    },
    {
      "url": "https://live-listing-proof.mattskowronis.workers.dev/v1/verify",
      "protocolBinding": "HTTP+JSON",
      "protocolVersion": "1.0"
    }
  ],
  "provider": {
    "organization": "Matthew Skowron",
    "url": "https://live-listing-proof.mattskowronis.workers.dev"
  },
  "version": "1.3.0",
  "documentationUrl": "https://live-listing-proof.mattskowronis.workers.dev/openapi.json",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false,
    "extendedAgentCard": false
  },
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "skills": [
    {
      "id": "verify_public_listing",
      "name": "Verify Public Listing",
      "description": "Verify a public product, classified, marketplace or auction listing and return supported listing facts plus machine-readable source/listing state.",
      "tags": [
        "listing-verification",
        "marketplace",
        "classifieds",
        "auction",
        "price-check",
        "listing-freshness"
      ],
      "examples": [
        "Verify this marketplace listing is still available before recommending it.",
        "Confirm the advertised price on this classified ad.",
        "Check whether this auction listing was removed.",
        "Validate listing facts before citing the source."
      ],
      "inputModes": [
        "application/json"
      ],
      "outputModes": [
        "application/json"
      ]
    }
  ],
  "securitySchemes": {
    "x402": {
      "type": "apiKey",
      "in": "header",
      "name": "PAYMENT-SIGNATURE",
      "description": "x402 exact scheme, $0.02 USDC on eip155:8453"
    }
  },
  "security": [
    {
      "x402": []
    }
  ],
  "protocol": "x402",
  "x402Version": 2,
  "environment": "production",
  "payment": {
    "method": "POST",
    "path": "/v1/verify",
    "scheme": "exact",
    "price": "$0.02",
    "network": "eip155:8453",
    "asset": "USDC",
    "payTo": "0x22B3D4485C8Dcd8FC4840a7570664747c9055530"
  },
  "input_schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "url",
      "claim"
    ],
    "properties": {
      "url": {
        "type": "string",
        "maxLength": 2048,
        "description": "Public HTTP or HTTPS listing page URL to inspect."
      },
      "claim": {
        "type": "string",
        "minLength": 3,
        "maxLength": 2000,
        "description": "Natural-language claim about current availability, price, and/or location."
      }
    }
  },
  "output_schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "verdict",
      "claim_supported",
      "final_url",
      "title",
      "price",
      "location",
      "evidence",
      "checked_at",
      "content_hash",
      "confidence",
      "source_status",
      "retrieval_method"
    ],
    "properties": {
      "verdict": {
        "type": "string",
        "enum": [
          "active",
          "sold",
          "expired",
          "removed",
          "blocked",
          "uncertain"
        ]
      },
      "claim_supported": {
        "type": "boolean"
      },
      "final_url": {
        "type": "string"
      },
      "title": {
        "type": [
          "string",
          "null"
        ]
      },
      "price": {
        "anyOf": [
          {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "amount",
              "currency",
              "text"
            ],
            "properties": {
              "amount": {
                "type": "number",
                "description": "Numeric amount in major units."
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 currency code."
              },
              "text": {
                "type": "string",
                "description": "Price as printed on the page."
              }
            }
          },
          {
            "type": "null"
          }
        ]
      },
      "location": {
        "type": [
          "string",
          "null"
        ]
      },
      "evidence": {
        "type": "array",
        "maxItems": 3,
        "items": {
          "type": "string",
          "maxLength": 240
        }
      },
      "checked_at": {
        "type": "string"
      },
      "content_hash": {
        "type": "string",
        "description": "SHA-256 hex of rendered HTML."
      },
      "confidence": {
        "type": "number",
        "minimum": 0,
        "maximum": 1
      },
      "source_status": {
        "type": "string",
        "enum": [
          "verified",
          "removed",
          "blocked",
          "unreachable",
          "unsupported",
          "insufficient_evidence"
        ]
      },
      "retrieval_method": {
        "type": "string",
        "enum": [
          "direct_http",
          "browser_run",
          "official_api",
          "unsupported"
        ]
      }
    }
  },
  "input_example": {
    "url": "https://example.com/listing/123",
    "claim": "This item is still available for under $30,000 in Maine."
  },
  "output_example": {
    "verdict": "active",
    "claim_supported": true,
    "final_url": "https://example.com/listing/123",
    "title": "2018 Cabin Cruiser",
    "price": {
      "amount": 27500,
      "currency": "USD",
      "text": "$27,500"
    },
    "location": "Portland, Maine",
    "evidence": [
      "Listed at $27,500",
      "Location: Portland, Maine",
      "Status: Available"
    ],
    "checked_at": "2026-08-17T13:53:08.000Z",
    "content_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "confidence": 0.96,
    "source_status": "verified",
    "retrieval_method": "direct_http"
  }
}