# x402 Seller Doctor – x402 Endpoint Auditor

> x402 Seller Doctor – x402 Endpoint Auditor is a paid API for AI agents from eu-tender-x402-v3-production.up.railway.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).

Audits a public x402-enabled API endpoint to verify it is correctly configured, returns a compliance score, and lists any failed checks.

## Facts

- Endpoint: POST https://eu-tender-x402-v3-production.up.railway.app/api/x402-seller-doctor?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-seller-doctor-x402-endpoint-auditor-fff0a847
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_43yt9sSv4bzMMIpL-4pnL

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-seller-doctor-x402-endpoint-auditor-fff0a847 -d '<json body>'
```

Example prompt: Run the x402 Seller Doctor on https://api.example.com/paid using a GET request and tell me the compliance score, verdict, and any failing checks.

## When to prefer this

Use this endpoint when you need to programmatically verify that an x402-enabled API endpoint is correctly configured before publishing it, integrating it into an agent workflow, or listing it on a marketplace. It is specifically designed for the x402 protocol and returns structured pass/fail findings that generic HTTP testers do not provide.

## Known failure modes

- Target URL is unreachable — network error or timeout with no score returned
- Target URL does not return a 402 status — audit fails with critical findings
- Malformed URL input — validation error before probe is attempted
- Target requires authentication the auditor cannot provide — incomplete audit results
- x402 version mismatch — observed version not matching expected spec

## How this service works

Pay-per-call B2B sales lead and procurement intelligence plus Base wallet data for agents. Search EU tenders/RFPs or inspect a Base wallet. Payments use x402 USDC on Base.

## Output

Returns a JSON object with an integer compliance score (0–100), a verdict string (e.g. 'ready'), a summary of checks run (total, passed, failed, critical failed), a list of specific findings for any failures, and observed HTTP metadata (status code, x402 version, accepts count) from probing the target URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "Public x402 endpoint to audit"
  },
  "body": {
   "description": "Optional JSON body for non-GET probes"
  },
  "method": {
   "type": "string",
   "default": "GET",
   "description": "HTTP method"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "score": 100,
  "method": "GET",
  "product": "x402 Seller Doctor",
  "summary": {
   "checks": 10,
   "failed": 0,
   "passed": 10,
   "critical_failed": 0
  },
  "verdict": "ready",
  "findings": [],
  "observed": {
   "http_status": 402,
   "x402_version": 2,
   "accepts_count": 1
  },
  "audited_url": "https://api.example.com/paid"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-seller-doctor-x402-endpoint-auditor-fff0a847/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from eu-tender-x402-v3-production.up.railway.app](https://www.zero.xyz/host/eu-tender-x402-v3-production.up.railway.app/llms.txt)