AI Inference · x402 · early usage

Payload Check: data-quality filter for agents

by seenly-payload-check.vercel.app · discovered, not yet claimed by its owner · updated 2026-10-09

30d calls1

30d payers1

MethodGET

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

Payload Check: data-quality filter for agents. Send any payload (tool/API output, scraped page, LLM answer, generated code, JSON, CSV) and get a 0-100 quality score, pass/warn/fail, tags and concrete issues: invalid or truncated JSON (with auto-repair), JSON Schema mismatches, syntax errors, bot-challenge/captcha/404 scrapes, LLM refusals, placeholders, repetition loops, mojibake. Deterministic, no LLM, payload not stored.

Tags: data-quality · validation · json-repair · scrape-check · guardrails · bazaar

Call contract

Method: GET
Input: json
Output: json
Last paid call: 2026-10-09

Input example from Bazaar metadata

{
  "content": "```json\n{\"name\": \"Acme Widget\", \"price\": 12.5, \"tags\": [\"tools\", \"home\",], \"sku\": \"N/A\"}\n```",
  "expect": "auto"
}

Output example

{
  "action": "Use repaired.content (auto-fixed JSON) or retry the source.",
  "check_version": "dq-0.1.0",
  "detected_type": "json",
  "issues": [
    {
      "code": "json_invalid",
      "message": "Not valid JSON: Unexpected token '`', \"```json\n{\"\"... is not valid JSON",
      "severity": "critical"
    },
    {
      "code": "placeholder_values",
      "message": "Placeholder-looking values (N/A, TODO, lorem ipsum, \"string\"...) at: sku",
      "severity": "minor"
    }
  ],
  "quality_score": 32,
  "repaired": {
    "content": "{\"name\": \"Acme Widget\", \"price\": 12.5, \"tags\": [\"tools\", \"home\"], \"sku\": \"N/A\"}",
    "note": "Mechanical repair only; check the steps (a closed truncation means data is missing).",
    "steps": [
      "removed markdown code fence",
      "removed trailing commas"
    ]
  },
  "tags": [
    "invalid_json",
    "repairable",
    "placeholder"
  ],
  "usable": false,
  "verdict": "fail"
}

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/42673.json for the price and payment options.
Pay. Call GET https://seenly-payload-check.vercel.app/api/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: $0.01 / 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	$0.01	0xeE6239F3E17bEBe5e89F21F29D74D68CAa0d78CE	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xeE6239F3E17bEBe5e89F21F29D74D68CAa0d78CE",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "properties": {
        "action": {
          "type": "string"
        },
        "detected_type": {
          "enum": [
            "json",
            "code",
            "text",
            "html",
            "csv"
          ],
          "type": "string"
        },
        "issues": {
          "items": {
            "properties": {
              "code": {
                "type": "string"
              },
              "location": {
                "type": "string"
              },
              "message": {
                "type": "string"
              },
              "severity": {
                "enum": [
                  "critical",
                  "major",
                  "minor",
                  "info"
                ],
                "type": "string"
              }
            },
            "type": "object"
          },
          "type": "array"
        },
        "quality_score": {
          "description": "100 = clean. Critical issue -60, major -25, minor -8.",
          "maximum": 100,
          "minimum": 0,
          "type": "integer"
        },
        "repaired": {
          "description": "Only for broken-but-fixable JSON: content (fixed JSON string), steps[].",
          "type": "object"
        },
        "stats": {
          "type": "object"
        },
        "tags": {
          "description": "e.g. invalid_json, truncated, schema_mismatch, scrape_failure, bot_challenge, llm_refusal, placeholder, repetitive, syntax_error, empty, clean",
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "usable": {
          "type": "boolean"
        },
        "verdict": {
          "enum": [
            "pass",
            "warn",
            "fail"
          ],
          "type": "string"
        }
      },
      "required": [
        "quality_score",
        "verdict",
        "usable",
        "tags",
        "issues"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

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

{
  "example": {
    "action": "string",
    "detected_type": "json",
    "issues": [
      {
        "code": "string",
        "location": "string",
        "message": "string",
        "severity": "critical"
      }
    ],
    "quality_score": 0,
    "repaired": {},
    "stats": {},
    "tags": [
      "string"
    ],
    "usable": true,
    "verdict": "pass"
  },
  "type": "string"
}

Examples

curl

curl "https://seenly-payload-check.vercel.app/api/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://seenly-payload-check.vercel.app/api/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://seenly-payload-check.vercel.app/api/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: seenly-payload-check.vercel.app
Endpoint: https://seenly-payload-check.vercel.app/api/check
Machine-readable: /resources/42673.json