# x402 Endpoint Health & Payment Parameter Vetter

> x402 Endpoint Health & Payment Parameter Vetter is a paid API for AI agents from api.fadeandco.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Probes a public HTTPS endpoint for x402 payment challenge details (networks, asset, price, pay-to address, CORS) without making a payment

## Facts

- Endpoint: GET https://api.fadeandco.workers.dev/api/agent-intel/x402-endpoint-health-vetting?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-endpoint-health-payment-parameter-vetter-3cbc4b56
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Tp8l5uSTPjftlGbbdB8nC

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-endpoint-health-payment-parameter-vetter-3cbc4b56
```

Example prompt: Before I pay anything, can you check what payment networks, asset, price, and pay-to address format that x402 endpoint at https://api.example.com/premium-data requires, and whether its CORS header is set correctly?

## When to prefer this

Use this endpoint when you need to inspect an x402-gated URL's payment parameters before committing funds — specifically to see which blockchain networks and assets are accepted, the price, the pay-to address format, and CORS configuration. Prefer it over manually reading 402 headers when you want a structured, parsed summary. Not suitable for verifying seller reputation, testing endpoint uptime, or actually executing a payment.

## Known failure modes

- Non-HTTPS or unreachable URLs return an error or null first-response
- Endpoints that don't return 402 at all yield a non-x402 verdict
- Endpoints with a 402 but no valid x402 accepts list yield '402_WITHOUT_X402_ACCEPTS' verdict
- Network timeouts may produce null response fields
- No payment is attempted so paywalled response bodies are not validated

## How this service works

Checks an x402 (HTTP 402 payment) endpoint before you pay: one unpaid GET, then the HTTP status, whether a 402 challenge with an accepts list is present, the payment networks, asset, price and pay-to address format, CORS header and response time. Does not pay, does not verify the seller's identity or reputation, and gives one sample, not uptime.

## Output

Returns a JSON object with: the URL checked, HTTP status code, a verdict string (e.g. '402_WITHOUT_X402_ACCEPTS' or valid x402), list of accepted payment networks, asset, price, pay-to address format, CORS allow-origin header value, response time in milliseconds, number of accepts, and a timestamp. Explicitly notes this is one unpaid sample and says nothing about uptime or seller identity.

## 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",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Public https:// endpoint address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://httpbin.org/status/402",
  "note": "One unpaid request. Says nothing about uptime, seller identity or reputation.",
  "first": null,
  "source": "https://httpbin.org/status/402",
  "verdict": "402_WITHOUT_X402_ACCEPTS",
  "networks": [],
  "checkedAt": "2026-10-23T09:35:20.497Z",
  "httpStatus": 402,
  "responseMs": 816,
  "acceptsCount": 0,
  "corsAllowOrigin": "*"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-endpoint-health-payment-parameter-vetter-3cbc4b56/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fadeandco.workers.dev](https://www.zero.xyz/host/api.fadeandco.workers.dev/llms.txt)