Security · x402 · early usage

Audit a real response against what the OpenAPI document promises for that operation

Audit a real response against what the OpenAPI document promises for that operation. Resolves the declared status exactly, by range such as 2XX, or through default, checks declared response headers are present, and validates the body against the declared sche…

by api.zfinia.com · discovered, not yet claimed by its owner · updated 2026-10-04

30d calls1

30d payers1

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Tags: openapi · response validation · contract drift · monitoring · developer tooling · bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-04

Input example from Bazaar metadata

{
  "request": {
    "method": "GET",
    "path": "/orders/{id}"
  },
  "response": {
    "body": {
      "id": "o-1",
      "status": "cancelled",
      "total": "42.50"
    },
    "headers": {
      "Content-Type": "application/json"
    },
    "status": 200
  },
  "specification": {
    "components": {
      "schemas": {
        "Order": {
          "properties": {
            "id": {
              "type": "string"
            },
            "legacy_ref": {
              "type": "string"
            },
            "status": {
              "enum": [
                "open",
                "shipped"
              ],
              "type": "string"
            },
            "total": {
              "type": "number"
            }
          },
          "required": [
            "id",
            "total"
          ],
          "type": "object"
        }
      },
      "securitySchemes": {
        "apiKey": {
          "in": "header",
          "name": "X-Api-Key",
          "type": "apiKey"
        }
      }
    },
    "info": {
      "title": "Orders API",
      "version": "1.4.0"
    },
    "openapi": "3.1.0",
    "paths": {
      "/legacy/export": {
        "get": {
          "operationId": "legacyExport",
          "responses": {
            "200": {
              "description": "A CSV export"
            }
          },
          "summary": "Legacy export"
        }
      },
      "/orders": {
        "get": {
          "operationId": "listOrders",
          "responses": {
            "200": {
              "content": {
                "application/json": {
                  "schema": {
                    "items": {
                      "$ref": "#/components/schemas/Order"
                    },
                    "type": "array"
                  }
                }
              },
              "description": "A page of orders"
            },
            "429": {
              "description": "Rate limited"
            }
          },
          "summary": "List orders"
        },
        "parameters": [
          {
            "in": "query",
            "name": "page",
            "schema": {
              "minimum": 1,
              "type": "integer"
            }
          }
        ],
        "post": {
          "operationId": "createOrder",
          "requestBody": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Order"
                }
              }
            }
          },
          "responses": {
            "201": {
              "content": {
                "application/json": {
                  "schema": {
                    "$ref": "#/components/schemas/Order"
                  }
                }
              },
              "description": "Created"
            }
          },
          "summary": "Create an order"
        }
      },
      "/orders/{id}": {
        "get": {
          "operationId": "getOrder",
          "parameters": [
            {
              "in": "path",
              "name": "id",
              "schema": {
                "type": "string"
              }
            }
          ],
          "responses": {
            "200": {
              "content": {
                "application/json": {
                  "schema": {
                    "$ref": "#/components/schemas/Order"
                  }
                }
              },
              "description": "The order"
            },
            "404": {
              "description": "Not found"
            }
          },
          "summary": "Fetch one order"
        }
      }
    },
    "security": [
      {
        "apiKey": []
      }
    ]
  }
}

Output example

{
  "assumptions": [
    "A status may be declared exactly, as a range such as 2XX, or through default, and the most specific declaration is used.",
    "You supply the observed response, so this works against an API behind authentication or on a private network."
  ],
  "body_checked": true,
  "complete": true,
  "conformant": false,
  "finding_count": 2,
  "findings": [
    {
      "code": "TYPE_MISMATCH",
      "detail": "GET /orders/{id}: response body Expected number, found string.",
      "operation": "GET /orders/{id}",
      "pointer": "/total",
      "status": "200"
    },
    {
      "code": "NOT_IN_ENUM",
      "detail": "GET /orders/{id}: response body \"cancelled\" is not one of the 2 permitted values.",
      "operation": "GET /orders/{id}",
      "pointer": "/status",
      "status": "200"
    }
  ],
  "findings_by_code": {
    "NOT_IN_ENUM": 1,
    "TYPE_MISMATCH": 1
  },
  "limitations": [
    "Conformance of one response against the supplied specification. Whether the specification is correct is not assessed.",
    "conformant is true only when the operation and status were declared and every declared constraint was evaluated and passed."
  ],
  "limits": {
    "maxClientOperations": 200,
    "maxFindings": 500,
    "maxOperations": 500,
    "maxRequestBodyBytes": 262144
  },
  "matched_operation": "GET /orders/{id}",
  "matched_status_declaration": "200",
  "not_examined": [],
  "observed_at": "2026-10-02T00:00:00.000Z",
  "request_id": "example-request",
  "service_id": "openapi_response_conformance_audit",
  "service_version": "1.0.0",
  "status": 200
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/34028.json for the price and payment options.
Pay. Call GET https://api.zfinia.com/x402/v1/openapi-response-conformance-audit. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.14 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 1 calls · 1 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.14	0x25e8245f07d5e4873987293dad666afbe56a9608	60s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x25e8245f07d5e4873987293dad666afbe56a9608",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "140000",
    "amountUsd": 0.14,
    "maxTimeoutSeconds": 60
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {},
  "type": "string"
}

Examples

curl

curl -X POST 'https://api.zfinia.com/x402/v1/openapi-response-conformance-audit' -H 'Content-Type: application/json' --data '{"request":{"method":"GET","path":"/orders/{id}"},"response":{"body":{"id":"o-1","status":"cancelled","total":"42.50"},"headers":{"Content-Type":"application/json"},"status":200},"specification":{"components":{"schemas":{"Order":{"properties":{"id":{"type":"string"},"legacy_ref":{"type":"string"},"status":{"enum":["open","shipped"],"type":"string"},"total":{"type":"number"}},"required":["id","total"],"type":"object"}},"securitySchemes":{"apiKey":{"in":"header","name":"X-Api-Key","type":"apiKey"}}},"info":{"title":"Orders API","version":"1.4.0"},"openapi":"3.1.0","paths":{"/legacy/export":{"get":{"operationId":"legacyExport","responses":{"200":{"description":"A CSV export"}},"summary":"Legacy export"}},"/orders":{"get":{"operationId":"listOrders","responses":{"200":{"content":{"application/json":{"schema":{"items":{"$ref":"#/components/schemas/Order"},"type":"array"}}},"description":"A page of orders"},"429":{"description":"Rate limited"}},"summary":"List orders"},"parameters":[{"in":"query","name":"page","schema":{"minimum":1,"type":"integer"}}],"post":{"operationId":"createOrder","requestBody":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Order"}}}},"responses":{"201":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Order"}}},"description":"Created"}},"summary":"Create an order"}},"/orders/{id}":{"get":{"operationId":"getOrder","parameters":[{"in":"path","name":"id","schema":{"type":"string"}}],"responses":{"200":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Order"}}},"description":"The order"},"404":{"description":"Not found"}},"summary":"Fetch one order"}}},"security":[{"apiKey":[]}]}}'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://api.zfinia.com/x402/v1/openapi-response-conformance-audit", {
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "body": "{\"request\":{\"method\":\"GET\",\"path\":\"/orders/{id}\"},\"response\":{\"body\":{\"id\":\"o-1\",\"status\":\"cancelled\",\"total\":\"42.50\"},\"headers\":{\"Content-Type\":\"application/json\"},\"status\":200},\"specification\":{\"components\":{\"schemas\":{\"Order\":{\"properties\":{\"id\":{\"type\":\"string\"},\"legacy_ref\":{\"type\":\"string\"},\"status\":{\"enum\":[\"open\",\"shipped\"],\"type\":\"string\"},\"total\":{\"type\":\"number\"}},\"required\":[\"id\",\"total\"],\"type\":\"object\"}},\"securitySchemes\":{\"apiKey\":{\"in\":\"header\",\"name\":\"X-Api-Key\",\"type\":\"apiKey\"}}},\"info\":{\"title\":\"Orders API\",\"version\":\"1.4.0\"},\"openapi\":\"3.1.0\",\"paths\":{\"/legacy/export\":{\"get\":{\"operationId\":\"legacyExport\",\"responses\":{\"200\":{\"description\":\"A CSV export\"}},\"summary\":\"Legacy export\"}},\"/orders\":{\"get\":{\"operationId\":\"listOrders\",\"responses\":{\"200\":{\"content\":{\"application/json\":{\"schema\":{\"items\":{\"$ref\":\"#/components/schemas/Order\"},\"type\":\"array\"}}},\"description\":\"A page of orders\"},\"429\":{\"description\":\"Rate limited\"}},\"summary\":\"List orders\"},\"parameters\":[{\"in\":\"query\",\"name\":\"page\",\"schema\":{\"minimum\":1,\"type\":\"integer\"}}],\"post\":{\"operationId\":\"createOrder\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}}},\"responses\":{\"201\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}},\"description\":\"Created\"}},\"summary\":\"Create an order\"}},\"/orders/{id}\":{\"get\":{\"operationId\":\"getOrder\",\"parameters\":[{\"in\":\"path\",\"name\":\"id\",\"schema\":{\"type\":\"string\"}}],\"responses\":{\"200\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}},\"description\":\"The order\"},\"404\":{\"description\":\"Not found\"}},\"summary\":\"Fetch one order\"}}},\"security\":[{\"apiKey\":[]}]}}"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
import json
res = httpx.request("POST", "https://api.zfinia.com/x402/v1/openapi-response-conformance-audit", json=json.loads("{\"request\":{\"method\":\"GET\",\"path\":\"/orders/{id}\"},\"response\":{\"body\":{\"id\":\"o-1\",\"status\":\"cancelled\",\"total\":\"42.50\"},\"headers\":{\"Content-Type\":\"application/json\"},\"status\":200},\"specification\":{\"components\":{\"schemas\":{\"Order\":{\"properties\":{\"id\":{\"type\":\"string\"},\"legacy_ref\":{\"type\":\"string\"},\"status\":{\"enum\":[\"open\",\"shipped\"],\"type\":\"string\"},\"total\":{\"type\":\"number\"}},\"required\":[\"id\",\"total\"],\"type\":\"object\"}},\"securitySchemes\":{\"apiKey\":{\"in\":\"header\",\"name\":\"X-Api-Key\",\"type\":\"apiKey\"}}},\"info\":{\"title\":\"Orders API\",\"version\":\"1.4.0\"},\"openapi\":\"3.1.0\",\"paths\":{\"/legacy/export\":{\"get\":{\"operationId\":\"legacyExport\",\"responses\":{\"200\":{\"description\":\"A CSV export\"}},\"summary\":\"Legacy export\"}},\"/orders\":{\"get\":{\"operationId\":\"listOrders\",\"responses\":{\"200\":{\"content\":{\"application/json\":{\"schema\":{\"items\":{\"$ref\":\"#/components/schemas/Order\"},\"type\":\"array\"}}},\"description\":\"A page of orders\"},\"429\":{\"description\":\"Rate limited\"}},\"summary\":\"List orders\"},\"parameters\":[{\"in\":\"query\",\"name\":\"page\",\"schema\":{\"minimum\":1,\"type\":\"integer\"}}],\"post\":{\"operationId\":\"createOrder\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}}},\"responses\":{\"201\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}},\"description\":\"Created\"}},\"summary\":\"Create an order\"}},\"/orders/{id}\":{\"get\":{\"operationId\":\"getOrder\",\"parameters\":[{\"in\":\"path\",\"name\":\"id\",\"schema\":{\"type\":\"string\"}}],\"responses\":{\"200\":{\"content\":{\"application/json\":{\"schema\":{\"$ref\":\"#/components/schemas/Order\"}}},\"description\":\"The order\"},\"404\":{\"description\":\"Not found\"}},\"summary\":\"Fetch one order\"}}},\"security\":[{\"apiKey\":[]}]}}"))
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: api.zfinia.com
Endpoint: https://api.zfinia.com/x402/v1/openapi-response-conformance-audit
Machine-readable: /resources/34028.json