API · x402

JSON parse error diagnosis for AI agents: Diagnose JSON parse errors, malformed JSON sy…

JSON parse error diagnosis for AI agents: Diagnose JSON parse errors, malformed JSON syntax, duplicate object keys, unexpected trailing commas and schema inference problems in a sanitized sample (max 4096 UTF-8 bytes). Returns syntax location, bounded trailin…

by NAIF Gravity · verified provider · updated 2026-11-03

What it does

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/74773.json for the price and payment options.
Pay. Call GET https://naifgravity.com/api/x402/json-validity-check. 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: $1 / 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	$1	0xEE39dAa7E6b20Fc772E9FDCA9762B69816738E25	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xEE39dAa7E6b20Fc772E9FDCA9762B69816738E25",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000000",
    "amountUsd": 1,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "additionalProperties": true,
  "description": "One-sample JSON result. INVALID is a diagnosis, not a successful repair.",
  "properties": {
    "correctedJson": {
      "description": "Canonical JSON; null for invalid input.",
      "type": [
        "string",
        "null"
      ]
    },
    "heavyWork": {
      "const": false
    },
    "inferredSchema": {
      "description": "Schema inferred from this sample, not the full external contract.",
      "type": [
        "object",
        "null"
      ]
    },
    "kind": {
      "const": "json_actionable_artifact"
    },
    "parseError": {
      "type": "string"
    },
    "productId": {
      "const": "json-validity-check"
    },
    "rawInputStored": {
      "const": false
    },
    "remainingScope": {
      "items": {
        "type": "string"
      },
      "type": "array"
    },
    "repairApplied": {
      "enum": [
        "none",
        "trailing_comma_removed"
      ],
      "type": "string"
    },
    "schemaNote": {
      "type": "string"
    },
    "status": {
      "enum": [
        "VALID",
        "REPAIRED_SAFE_PATTERN",
        "INVALID"
      ],
      "type": "string"
    },
    "validExample": {},
    "validationTest": {
      "properties": {
        "code": {
          "type": "string"
        },
        "expected": {
          "const": "PASS"
        },
        "kind": {
          "const": "deterministic_round_trip"
        },
        "roundTripEqual": {
          "type": "boolean"
        },
        "runtime": {
          "const": "javascript"
        },
        "sha256": {
          "pattern": "^[0-9a-f]{64}$",
          "type": "string"
        },
        "topLevelType": {
          "enum": [
            "object",
            "array",
            "string",
            "integer",
            "number",
            "boolean",
            "null"
          ]
        }
      },
      "type": [
        "object",
        "null"
      ]
    }
  },
  "required": [
    "productId",
    "kind",
    "status",
    "correctedJson",
    "inferredSchema",
    "validExample",
    "validationTest",
    "rawInputStored",
    "heavyWork"
  ],
  "type": "object"
}

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

{
  "correctedJson": "string",
  "heavyWork": null,
  "inferredSchema": {},
  "kind": null,
  "parseError": "string",
  "productId": null,
  "rawInputStored": null,
  "remainingScope": [
    "string"
  ],
  "repairApplied": "none",
  "schemaNote": "string",
  "status": "VALID",
  "validExample": null,
  "validationTest": {
    "code": "string",
    "expected": null,
    "kind": null,
    "roundTripEqual": true,
    "runtime": null,
    "sha256": "string",
    "topLevelType": "object"
  }
}

Examples

curl

curl "https://naifgravity.com/api/x402/json-validity-check"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://naifgravity.com/api/x402/json-validity-check");
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://naifgravity.com/api/x402/json-validity-check")
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: NAIF Gravity
Endpoint: https://naifgravity.com/api/x402/json-validity-check
Machine-readable: /resources/74773.json