# x402 Listing Doctor

> x402 Listing Doctor is a paid API for AI agents from minty-sprout.onrender.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-11-01).

Diagnoses why a paid x402 endpoint is not attracting buyers by running preflight checks, CDP validation, and marketplace presence checks, then returning concrete actionable fixes.

## Facts

- Endpoint: POST https://minty-sprout.onrender.com/v1/x402-listing-doctor?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-listing-doctor-09c25579
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JWVW_ejAuSbQ242xYOBH8

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-listing-doctor-09c25579 -d '<json body>'
```

Example prompt: Can you run the x402 listing doctor on my endpoint at https://my-api.example.com/paid-route and tell me exactly why it's not getting any buyers and what I need to fix?

## When to prefer this

Use this endpoint when you are an x402 seller trying to understand why your paid endpoint has no buyers. It combines x402 preflight, Coinbase CDP validation, and marketplace presence checks (CDP Bazaar, 402index) into a single deterministic diagnostic report with concrete fixes — more actionable than running each check separately. Prefer this over the basic x402-preflight endpoint when you need a full seller-side audit rather than just a buyer-side readiness check.

## Known failure modes

- Target endpoint is unreachable or sleeping (slow host on free tier — flagged as an issue in output)
- Malformed URL input returns validation error
- Target endpoint returns unexpected non-402 and non-400 status codes that may confuse checks
- Rate limits or network timeouts on CDP or 402index external checks

## How this service works

x402 listing doctor for sellers: why a paid endpoint gets no buyers. Runs the x402 preflight, Coinbase's CDP validator, and presence checks in the CDP Bazaar and 402index, then returns concrete fixes: 402 before input validation, Bazaar metadata, description over 500 chars or instruction-like, slow or sleeping host, no settled sale yet. Input: endpoint URL, optionally 'POST <url>'. Deterministic, no LLM.

## Output

Returns a JSON object with a 'verdict' (block or pass), a 'fixes' array of concrete actionable issues tagged as [block] or [info], CDP validation details including which checks failed, and a 'listed' object showing presence in 402index and CDP Bazaar.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "maxLength": 8000,
   "description": "URL of your paid x402 endpoint, optionally prefixed with GET or POST"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://money-reactor.makar52nn2016.workers.dev/api/http-check",
  "fixes": [
   "[block] returned HTTP 400, not 402 Payment Required",
   "[block] CDP check returns_402: Endpoint returned HTTP 400 instead of 402",
   "[info] not in 402index: free registration at POST https://402index.io/api/v1/register"
  ],
  "listed": {
   "402index": false,
   "cdp_bazaar": false
  },
  "verdict": "block",
  "cdp_validation": {
   "valid": false,
   "outcome": "rejected",
   "failed_checks": [
    "returns_402"
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-listing-doctor-09c25579/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from minty-sprout.onrender.com](https://www.zero.xyz/host/minty-sprout.onrender.com/llms.txt)