# x-402.online x402 Endpoint Inspector

> x-402.online x402 Endpoint Inspector is a paid API for AI agents from api.x-402.online, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Probes an x402-enabled HTTP endpoint to verify it returns a valid payment challenge and extracts its pricing and payment metadata.

## Facts

- Endpoint: GET https://api.x-402.online/v1/x402/inspect?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x-402-online-x402-endpoint-inspector-32f5f8ed
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CsJLRCO9mg4MvQJxkq2S9

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 x-402-online-x402-endpoint-inspector-32f5f8ed
```

Example prompt: Can you probe the x402 endpoint at https://api.example.com/data and tell me whether it's returning a valid payment challenge, what network and asset it uses, who the payment goes to, and how much it costs in USDC?

## When to prefer this

Use this endpoint when you need to non-destructively inspect an x402-protected API to verify its payment challenge is valid and read its pricing metadata without actually making a payment. It is ideal for health checks, auditing, onboarding verification, and monitoring x402 endpoints over time. Prefer it over manually constructing HTTP requests when you need structured, parsed output of challenge fields like payTo, asset, amount, and network.

## Known failure modes

- Target endpoint is unreachable or times out — returns an error indicating the URL could not be probed
- Target endpoint does not return a 402 status — challenge validity fails
- Malformed or missing payment challenge headers — reported as invalid challenge
- Unsupported x402 scheme or version — may not parse correctly
- Invalid URL input — returns a validation error

## How this service works

Check that an x402 endpoint still returns a valid payment challenge, and read its price and recipient. Probe an x402 endpoint and report whether it still returns a valid payment challenge: HTTP status, challenge source (v2 header or legacy body), scheme, network, asset, payTo, amount in atomic units and in USDC, and a…

## Output

Returns the HTTP status code of the probed endpoint, the challenge source (v2 header or legacy body), payment scheme, network, asset type, payTo wallet address, amount in atomic units, amount in human-readable USDC, and an overall validity assessment of the payment challenge.

## 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": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x-402-online-x402-endpoint-inspector-32f5f8ed/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x-402.online](https://www.zero.xyz/host/api.x-402.online/llms.txt)