# PennyRail Block Number Lookup

> PennyRail Block Number Lookup is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the latest block number from the Nano blockchain via a paid settlement endpoint

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/chain.block-number--latest-block
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-block-number-lookup-de4ec22b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZSHuAvGG5b8g8ZFCuNgFv

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 pennyrail-block-number-lookup-de4ec22b -d '<json body>'
```

Example prompt: What is the current latest block number on the Nano blockchain right now?

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call lookup of the current Nano blockchain block height without running your own node. It is ideal for agents or applications that need occasional chain state checks without maintaining infrastructure, and are comfortable with x402 micropayment settlement at $0.001 USDC per call.

## Known failure modes

- Payment not included or invalid x402 payment header — 402 Payment Required
- Nano node unavailable or network error — 503 or timeout response
- Malformed input object — 400 Bad Request
- Rate limiting if payment insufficient — 429 Too Many Requests

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the latest (most recent) block number or block height on the Nano blockchain, representing the current chain tip.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-block-number-lookup-de4ec22b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)