# x402 Ping

> x402 Ping is a paid API for AI agents from onchaincheck.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-29).

Minimal end-to-end x402 payment health check: pays $0.001 USDC and returns server time and payment network, confirming the full sign-and-settle flow works.

## Facts

- Endpoint: GET https://onchaincheck.dev/x402/ping?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-ping-718727c1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zSt5ehWT-NA9J9RIu0_1z

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-ping-718727c1
```

Example prompt: Send a live x402 ping to onchaincheck.dev — pay the $0.001 USDC and confirm that my client can sign and settle a payment all the way through, then show me the server time and network it responded on.

## When to prefer this

Use this endpoint when you need to verify that an x402 payment client (wallet, signing library, or agent payment middleware) can successfully complete the full sign-authorize-settle cycle end-to-end. It is the cheapest possible live x402 call ($0.001 USDC) and is purpose-built as a health check, making it ideal for smoke tests, CI pipelines, integration debugging, and onboarding validation before sending larger or more complex paid API requests.

## Known failure modes

- Insufficient USDC balance — payment cannot be settled, returns 402 with payment required details
- Invalid or malformed x402 payment header — server rejects the signed payment
- Network mismatch — client signed for wrong chain ID, payment rejected
- Wallet not authorized or private key misconfigured — signing fails before request is sent
- Server temporarily unavailable — connection timeout or 5xx response

## How this service works

The smallest real x402 paid call: costs $0.001 in USDC and returns ok with the server time and payment network. Useful for checking that an x402 client can sign and settle a payment end to end.

## Output

A JSON object with: ok (boolean true on success), paid (boolean true confirming payment settled), price (string, '$0.001'), network (EIP-155 chain identifier string, e.g. 'eip155:84532'), and serverTime (ISO 8601 UTC timestamp of when the server processed the request).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true,
  "price": "$0.001",
  "network": "eip155:84532",
  "serverTime": "2026-10-22T15:49:53.808Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-ping-718727c1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchaincheck.dev](https://www.zero.xyz/host/onchaincheck.dev/llms.txt)