# Toolbelt402 x402-Check — x402 Compliance Scorer

> Toolbelt402 x402-Check — x402 Compliance Scorer is a paid API for AI agents from toolbelt402.catalystdesk.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-10).

Scores how well a given URL/endpoint complies with the x402 pay-per-call protocol and suggests specific fixes to improve compliance.

## Facts

- Endpoint: GET https://toolbelt402.catalystdesk.workers.dev/v1/x402-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/toolbelt402-x402-check-x402-compliance-scorer-92152c51
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uK5Bk_j2_W18NdfvMhMkI

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 toolbelt402-x402-check-x402-compliance-scorer-92152c51
```

Example prompt: Can you check how x402-compliant my endpoint at https://myapi.example.com/chat is and tell me what I need to fix to get it discoverable on the bazaar?

## When to prefer this

Use this endpoint when you need to programmatically audit an HTTP endpoint for x402 protocol compliance and get structured, actionable improvement suggestions. Prefer this over manual inspection when you want a numeric score and specific fix list in JSON form. Best suited for developers building or iterating on x402-enabled APIs who want automated feedback.

## Known failure modes

- Missing or invalid 'url' query parameter — endpoint may return an error or score of 0
- Target URL is unreachable or times out — checker cannot probe the endpoint
- Target endpoint does not respond with HTTP headers expected by x402 — score will be low with generic suggestions
- Payment not made via x402/USDC on Base — request returns 402 without result

## How this service works

Pay-per-call utility API for AI agents — x402, USDC on Base, no API key.

## Output

Returns a JSON object with a numeric compliance score (0–100) and an array of actionable fix suggestions (e.g. 'Add the bazaar discovery extension') that the developer should implement to improve x402 compliance and discoverability.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "url": {
       "type": "string"
      }
     }
    }
   }
  },
  "output": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "fixes": [
   "Add the bazaar discovery extension"
  ],
  "score": 82
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/toolbelt402-x402-check-x402-compliance-scorer-92152c51/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toolbelt402.catalystdesk.workers.dev](https://www.zero.xyz/host/toolbelt402.catalystdesk.workers.dev/llms.txt)