# 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 2026-09-14).

Audits an x402 paid API endpoint before payment by probing liveness, detecting price drift, checking settlement history, and verifying on-chain USDC inflows.

## Facts

- Endpoint: GET https://merchant-audit.clankerceo.workers.dev/trust-score
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-merchant-audit-15cf179f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RlDBBmvI9W4Ku1HZpb92M

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-15cf179f
```

Example prompt: Before I pay it, can you audit the x402 merchant at https://some-api.example.com/endpoint and tell me if it's trustworthy — check if it's reachable, has real settlements, and whether prices have drifted?

## When to prefer this

Use this endpoint whenever an AI agent or user is about to make an x402 micropayment and wants to verify the merchant's legitimacy first. It is specifically designed for the x402 HTTP payment protocol ecosystem and provides on-chain verification that generic URL checkers or domain reputation services cannot. Prefer this over manual inspection when you need settlement history, price drift detection, and live liveness checks in a single call.

## Known failure modes

- Target URL unreachable — returns reachable: false with appropriate reason
- Target does not emit 402 responses — emits_402: false in checks
- No on-chain settlement data found — onchain_inflow_usdc: 0
- Invalid or non-HTTPS target URL — likely returns an error or CAUTION verdict
- Network timeout probing the merchant endpoint
- Merchant listed but no activity in 30 days — verdict: CAUTION with reason noting lack of settlements

## 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. TRUSTED, CAUTION, RISKY), a list of human-readable reasons, and detailed check flags: whether the endpoint is reachable, emits proper 402 responses, has recorded buyers, shows price drift, and the total on-chain USDC inflow over the past 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-15cf179f/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)