# Listing Doctor — x402 Endpoint Diagnostics

> Listing Doctor — x402 Endpoint Diagnostics is a paid API for AI agents from listing-doctor.node01.org, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-27).

Diagnoses x402 paid endpoint listings by checking the 402 challenge, payment headers, resource URL, Bazaar extension, price/asset/network/payTo fields, and discovery catalog inclusion, then returns a concrete verdict with failing checks and fixes.

## Facts

- Endpoint: GET https://listing-doctor.node01.org/api/listing-doctor?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/listing-doctor-x402-endpoint-diagnostics-afb8bae3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__mcKA_TEyD5LhK2CUyYtu

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 listing-doctor-x402-endpoint-diagnostics-afb8bae3
```

Example prompt: Can you run a full x402 listing diagnosis on my endpoint at https://myapi.example.com/api/pay and tell me exactly what's misconfigured — the payment headers, price fields, payTo address, and whether it's showing up in the discovery catalog?

## When to prefer this

Use this endpoint when you need to debug why an x402-compliant paid API endpoint is not discoverable, not paying out correctly, or failing validation checks. It is the go-to diagnostic tool specifically for x402 protocol compliance and Bazaar/x402scan catalog discovery issues, rather than general HTTP debugging or non-x402 payment systems.

## Known failure modes

- Target URL is unreachable or times out — diagnosis cannot be completed
- Target URL does not return a 402 status — is_402 check fails
- Malformed or missing input URL parameter — returns validation error
- Target endpoint blocks the diagnostic probe — partial results returned
- Catalog indexer not yet updated — in_payai_catalog may show false even for valid endpoints

## How this service works

Send your endpoint URL. It checks the unpaid 402 challenge, the PAYMENT-REQUIRED header, the declared resource URL, the Bazaar extension, the price/asset/network/payTo fields and the discovery catalog, then returns a concrete diagnosis with the failing checks and the fix.

## Output

A JSON object containing a map of individual check results (e.g. is_402, reachable, in_payai_catalog), the target URL that was diagnosed, a human-readable verdict string describing the overall status (e.g. 'PAYABLE-NOT-INDEXED'), and a timestamp of when the diagnosis was performed. Failing checks are highlighted so the developer knows exactly what to fix.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "URL of the x402 endpoint to diagnose"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "checks": {
   "is_402": true,
   "reachable": true,
   "in_payai_catalog": false
  },
  "target": "https://example.com/api/pay",
  "verdict": "PAYABLE-NOT-INDEXED (pay, then wait for indexer)",
  "diagnosed_at": "2026-10-08T02:10:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/listing-doctor-x402-endpoint-diagnostics-afb8bae3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from listing-doctor.node01.org](https://www.zero.xyz/host/listing-doctor.node01.org/llms.txt)