# trust402 x402 Endpoint Prober

> trust402 x402 Endpoint Prober is a paid API for AI agents from trust402.vercel.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Runs a live probe against an x402-protected endpoint to assess its 402 challenge and payment-flow readiness without actually paying.

## Facts

- Endpoint: POST https://trust402.vercel.app/api/trust/check-x402
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/trust402-x402-endpoint-prober-445729bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sJZ-Wn_zSJhXU7cmbfvLv

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 trust402-x402-endpoint-prober-445729bd -d '<json body>'
```

Example prompt: Can you probe https://api.example.com/premium-data with a GET request to check if its x402 challenge flow is properly set up and confirm the price doesn't exceed $0.10 USD?

## When to prefer this

Use this endpoint when you need to verify that an x402-protected API is correctly configured and live before integrating or routing payments through it. Ideal for pre-flight checks, integration testing, or auditing x402 endpoints for price compliance — especially when you want to inspect the 402 challenge structure without committing to a payment.

## Known failure modes

- Target endpoint is unreachable or times out — probe returns connectivity error
- Endpoint does not return a 402 response — flagged as not x402-compliant
- Price exceeds expectedPriceUsd — flagged as price mismatch
- Invalid or malformed URI provided — validation error before probe
- Endpoint returns 402 but with malformed payment challenge — partial compliance result

## How this service works

Run a fast live probe for one x402 endpoint and summarize challenge/payment-flow readiness.

## Output

A summary of the x402 endpoint's challenge and payment-flow readiness, including whether the endpoint returns a valid 402 response, details of the payment challenge, and whether the price falls within the expected maximum USD threshold — all without actually completing a payment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "method": {
   "enum": [
    "GET",
    "POST",
    "PUT",
    "PATCH",
    "DELETE",
    "HEAD"
   ],
   "type": "string",
   "default": "GET"
  },
  "endpoint": {
   "type": "string",
   "format": "uri",
   "description": "x402 endpoint to probe without paying."
  },
  "expectedPriceUsd": {
   "type": "number",
   "description": "Expected maximum price in USD."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/trust402-x402-endpoint-prober-445729bd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from trust402.vercel.app](https://www.zero.xyz/host/trust402.vercel.app/llms.txt)