# x402 Payment Requirements Probe

> x402 Payment Requirements Probe is a paid API for AI agents from well-012-x402-probe.mmelnyk2000.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-20).

Probes a public HTTPS URL to detect x402 payment requirements without paying, returning status, latency, parsed payment info, networks, and minimum price.

## Facts

- Endpoint: POST https://well-012-x402-probe.mmelnyk2000.workers.dev/api/x402-probe?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-payment-requirements-probe-ddca7e59
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Akfg_skBxvuXwS6sCUPza

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-payment-requirements-probe-ddca7e59 -d '<json body>'
```

Example prompt: Can you probe https://api.example.com/resource to check whether it requires x402 payment — without actually paying — and tell me the minimum price, supported networks, and whether the payment schema parses correctly?

## When to prefer this

Use this endpoint when you need to discover whether a public HTTPS URL implements x402 payment gating before committing any funds. Ideal for agents that need to inspect payment requirements, compare prices across x402 services, validate that a 402 response is well-formed, or build dashboards of x402-enabled APIs — without incurring the cost or side effects of actually paying. Not suitable for non-HTTPS targets or for endpoints behind private networks.

## Known failure modes

- Non-HTTPS URLs (http, file, data, localhost, private IPs) are rejected with an error
- Requests that exceed ~12 seconds timeout are capped
- Responses larger than ~200KB are truncated or rejected
- More than 5 redirects causes the probe to abort
- If the remote server returns no x402 headers, payment fields will be absent or null
- Malformed payment-requirements headers may cause schema parse flag to be false

## How this service works

Unpaid probe of a public https URL for x402 payment requirements ($0.005 USDC). Never pays. Returns HTTP status, latency, whether 402/payment-requirements parse, networks, min price, schema flag. https only; caps ~12s, 200KB, 5 redirects. Factual only; as is, no guarantee. Not a rating or certification. Provided as is, with no warranty or guarantee of accuracy or fitness. Nothing is stored.

## Output

Returns an object with HTTP status code, response latency, a boolean indicating whether a 402/payment-requirements response was detected, parsed payment networks, minimum price, a schema validity flag, and any redirect information — without ever sending payment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "description": "https URL of an x402 resource or MCP origin to probe unpaid. http/file/data/localhost/private IPs rejected."
  },
  "method": {
   "type": "string",
   "description": "Optional HTTP method: GET (default) or POST (empty JSON body)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-payment-requirements-probe-ddca7e59/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from well-012-x402-probe.mmelnyk2000.workers.dev](https://www.zero.xyz/host/well-012-x402-probe.mmelnyk2000.workers.dev/llms.txt)