# Hearth x402 Seller Audit

> Hearth x402 Seller Audit is a paid API for AI agents from 138-197-15-135.sslip.io, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-31).

Audits an x402 payment-gated API endpoint for buyer safety, protocol compliance, and best practices, returning a grade, score, and actionable fixes.

## Facts

- Endpoint: GET https://138-197-15-135.sslip.io/v1/x402/seller-audit?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hearth-x402-seller-audit-65d76ca4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VlNnRM4NiMGWsHpeINh4r

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability hearth-x402-seller-audit-65d76ca4
```

Example prompt: Can you run a Hearth seller audit on my x402 endpoint at https://myapi.example.com/v1/data to check if it's safe and compliant for buyers to call?

## When to prefer this

Use this endpoint when you are an x402 API seller or developer who wants to validate, debug, or improve a payment-gated endpoint before or after listing it. It is specifically designed for the x402 protocol (USDC micropayments on Base) and checks buyer safety, protocol correctness, and metadata quality in one call — unlike generic API linters or health checkers that have no knowledge of x402 semantics.

## Known failure modes

- Endpoint URL is unreachable or returns unexpected non-402 status — audit may still complete with failed checks noted
- Invalid or malformed URL returns a validation error
- Endpoint is too slow to respond within timeout — partial results or timeout error returned
- Network errors to the target endpoint cause check failures rather than audit failures
- Method parameter ignored if the endpoint doesn't support it

## How this service works

x402 pay-safety precheck, ranked x402 API discovery, onchain (Base/EVM/Solana) data and web-to-Markdown for AI agents. Pay per call with x402 (USDC on Base).

## Output

Returns a JSON object with the endpoint URL, an A–F letter grade, a numeric score (0–100), an array of individual check results (each with an id, pass/fail status, detail, and weight), counts of passed and failed checks, an array of top recommended fixes (each with title, why, and how), and a buyerSafety object with a sub-score and a plain-language verdict (e.g. 'caution' or 'safe').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "queryParams"
   ],
   "properties": {
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Your x402 endpoint URL"
      },
      "method": {
       "type": "string",
       "description": "GET or POST (default: try GET then POST)"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [],
     "properties": {
      "url": {
       "type": [
        "string",
        "null"
       ]
      },
      "grade": {
       "type": [
        "string",
        "null"
       ]
      },
      "score": {
       "type": [
        "integer",
        "null"
       ]
      },
      "checks": {
       "type": [
        "array",
        "null"
       ]
      },
      "failed": {
       "type": [
        "integer",
        "null"
       ]
      },
      "passed": {
       "type": [
        "integer",
        "null"
       ]
      },
      "schema": {
       "type": [
        "string",
        "null"
       ]
      },
      "topFixes": {
       "type": [
        "array",
        "null"
       ]
      },
      "buyerSafety": {
       "type": [
        "object",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://seller.example/api/x",
  "grade": "C",
  "score": 72,
  "checks": [
   {
    "id": "status_402",
    "ok": true,
    "detail": "unpaid GET returned HTTP 402",
    "weight": 15
   }
  ],
  "failed": 6,
  "passed": 17,
  "schema": "hearth.seller-audit.v1",
  "topFixes": [
   {
    "how": "…",
    "why": "…",
    "title": "Add an input schema"
   }
  ],
  "buyerSafety": {
   "score": 60,
   "verdict": "caution"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hearth-x402-seller-audit-65d76ca4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 138-197-15-135.sslip.io](https://www.zero.xyz/host/138-197-15-135.sslip.io/llms.txt)