# 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 before payment by live-probing it, detecting price drift, checking settlement history, and verifying on-chain USDC inflows.

## Facts

- Endpoint: GET https://merchant-audit.clankerceo.workers.dev/due-diligence
- 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-9702a414
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sgCAQPEVHDUovmrI0MVCp

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-9702a414
```

Example prompt: Before I pay it, can you audit the x402 endpoint at https://some-merchant.com/api/data and tell me whether it's reachable, has real settlement history, and whether the price has drifted — I want a PASS, CAUTION, or FAIL verdict.

## When to prefer this

Use this endpoint whenever an AI agent is about to make a payment to an unknown or semi-trusted x402 merchant and needs pre-payment due diligence. Prefer this over manual inspection when you need live reachability probing, on-chain settlement verification, and price drift detection in a single call. Especially valuable for new merchant integrations, recurring payment workflows, or any scenario where financial risk from a fraudulent or broken x402 endpoint is a concern.

## Known failure modes

- Target URL is unreachable — reachable: false returned with appropriate reason
- Target does not emit 402 — emits_402: false, verdict likely FAIL
- No on-chain settlement data found — onchain_inflow_usdc: 0, verdict likely CAUTION
- Price drift detected — price_drift: true included in reasons
- Invalid or missing target query parameter — likely 400 error or malformed response
- Endpoint listed but no settlements in 30 days — verdict CAUTION with explanatory reason

## 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 (PASS, CAUTION, or FAIL), an array of human-readable reasons, and a checks object containing: whether the endpoint is reachable, whether it emits HTTP 402, whether it has real buyers, whether price drift was detected, and the total on-chain USDC inflow over 30 days.

## 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-9702a414/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)