# x402 Merchant Audit

> x402 Merchant Audit is a paid API for AI agents from merchant-audit.clankerceo.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Audits an x402 paid API endpoint for reachability, price integrity, settlement history, and on-chain payment verification before you pay it.

## Facts

- Endpoint: GET https://merchant-audit.clankerceo.workers.dev/merchant-audit
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-merchant-audit-839dd6e2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vnI1D0Crqtmgj4X3TMomX

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 x402-merchant-audit-839dd6e2
```

Example prompt: Before I pay it, audit the x402 merchant at https://some-paid-api.com/data-endpoint — check if it's reachable, actually emits 402, has real settlement history, and whether the price has drifted.

## When to prefer this

Use this endpoint when an AI agent or user is about to make an x402 micropayment and needs to verify the target merchant's legitimacy, activity, and pricing integrity before spending USDC. It is the right choice when you need a pre-payment due-diligence check specific to the x402 protocol, combining live probing, on-chain data, and settlement history in a single call.

## Known failure modes

- Target URL is unreachable — reachable flag returns false
- Target does not emit HTTP 402 — emits_402 returns false, verdict likely CAUTION or UNSAFE
- No on-chain settlement history found — onchain_inflow_usdc is 0 and has_buyers is false
- Price drift detected — price_drift flag is true, indicating inconsistent pricing
- Invalid or malformed target URL — request may fail or return an error
- Endpoint itself is unavailable (Cloudflare Worker downtime)

## How this service works

Audit any x402 merchant before you pay it. Live probe, price-drift detection, settlement history and on-chain payment verification.

## Output

Returns a JSON object with: a verdict (e.g. CAUTION, OK, UNSAFE), individual check results (reachable, emits_402, has_buyers, price_drift, onchain_inflow_usdc), the audited target URL, and a list of human-readable reasons explaining the verdict.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "enum": [
      "http"
     ],
     "type": "string"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "target"
     ],
     "properties": {
      "target": {
       "type": "string",
       "description": "Absolute https URL of the x402 resource to audit."
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "enum": [
      "json"
     ],
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "checks": {
   "emits_402": true,
   "reachable": true,
   "has_buyers": false,
   "price_drift": false,
   "onchain_inflow_usdc": 0
  },
  "target": "https://example-merchant.com/api/some-service",
  "reasons": [
   "listed but no settlements in 30d"
  ],
  "verdict": "CAUTION"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-merchant-audit-839dd6e2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from merchant-audit.clankerceo.workers.dev](https://www.zero.xyz/host/merchant-audit.clankerceo.workers.dev/llms.txt)