API · x402

JSON Schema validation API for AI agents, LLM structured outputs, API responses, webhoo…

Name: JSON Schema validation API for AI agents, LLM structured outputs, API responses, webhook p
Price: 0.005 USD
Availability: InStock

by json-contract-tester-api.falcon-project-ai.workers.dev · verified provider · updated 2026-11-04

What it does

JSON Schema validation API for AI agents, LLM structured outputs, API responses, webhook payloads, and backend data contracts. Validate 1–10 JSON samples in one batch against a documented JSON Schema subset; receive per-sample PASS/FAIL results and structured JSON Pointer diagnostics for contract testing and regression checks. Not full JSON Schema; the pattern keyword is unsupported. $0.005 USDC per batch on Base Mainnet via x402 v2 exact.

Tags: json-schema-validation · api-response-validation · ai-agent-output · structured-output · webhook-validation · contract-testing · regression-testing

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/74954.json for the price and payment options.
Pay. Call GET https://json-contract-tester-api.falcon-project-ai.workers.dev/v1/validate-batch. 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: $0.005 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.005	0xFEFA6Cb78Cb79bc140Cd776e038d2093F7A170a5	60s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xFEFA6Cb78Cb79bc140Cd776e038d2093F7A170a5",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "5000",
    "amountUsd": 0.005,
    "maxTimeoutSeconds": 60
  }
]

Schemas

Output schema (JSON Schema)

{
  "type": "object",
  "required": [
    "reportVersion",
    "tool",
    "valid",
    "summary",
    "results",
    "limitation"
  ],
  "properties": {
    "reportVersion": {
      "const": "1.0"
    },
    "tool": {
      "const": "JSON Contract Tester API"
    },
    "valid": {
      "type": "boolean"
    },
    "summary": {
      "type": "object",
      "required": [
        "total",
        "passed",
        "failed"
      ],
      "properties": {
        "total": {
          "type": "integer"
        },
        "passed": {
          "type": "integer"
        },
        "failed": {
          "type": "integer"
        }
      }
    },
    "results": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "id",
          "passed",
          "errors"
        ],
        "properties": {
          "id": {
            "type": "string"
          },
          "passed": {
            "type": "boolean"
          },
          "errors": {
            "type": "array",
            "items": {
              "type": "object",
              "required": [
                "instancePath",
                "schemaPath",
                "keyword",
                "message",
                "expected",
                "actual"
              ],
              "properties": {
                "instancePath": {
                  "type": "string"
                },
                "schemaPath": {
                  "type": "string"
                },
                "keyword": {
                  "type": "string"
                },
                "message": {
                  "type": "string"
                },
                "expected": {},
                "actual": {}
              }
            }
          }
        }
      }
    },
    "limitation": {
      "type": "string"
    }
  }
}

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

{
  "reportVersion": null,
  "tool": null,
  "valid": true,
  "summary": {
    "total": 0,
    "passed": 0,
    "failed": 0
  },
  "results": [
    {
      "id": "string",
      "passed": true,
      "errors": [
        {
          "instancePath": "string",
          "schemaPath": "string",
          "keyword": "string",
          "message": "string",
          "expected": null,
          "actual": null
        }
      ]
    }
  ],
  "limitation": "string"
}

Examples

curl

curl "https://json-contract-tester-api.falcon-project-ai.workers.dev/v1/validate-batch"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://json-contract-tester-api.falcon-project-ai.workers.dev/v1/validate-batch");
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
res = httpx.get("https://json-contract-tester-api.falcon-project-ai.workers.dev/v1/validate-batch")
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: json-contract-tester-api.falcon-project-ai.workers.dev
Endpoint: https://json-contract-tester-api.falcon-project-ai.workers.dev/v1/validate-batch
Machine-readable: /resources/74954.json