# PennyRail Nano Chain Block Number – Proven Block Number Lookup

> PennyRail Nano Chain Block Number – Proven 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 2026-09-14).

Returns the current block number and the latest proven block number on a nano chain via a paid settlement endpoint.

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/chain.block-number--proven-block-number
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-nano-chain-block-number-proven-block-number-lookup-2a01d361
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7as4cO-tCG4Pi45liuEuZ

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-nano-chain-block-number-proven-block-number-lookup-2a01d361 -d '<json body>'
```

Example prompt: What is the current block number and the latest proven block number on the nano chain right now?

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call lookup of the current and proven block numbers on a nano chain for settlement, finality checking, or synchronization purposes — particularly in automated agent workflows that require on-chain state without running a full node.

## Known failure modes

- Invalid or missing input object returns a 400 error
- Payment not included or insufficient USDC triggers a 402 Payment Required response
- Chain node unavailable or unreachable returns a 503 or timeout
- Malformed response if the underlying chain RPC is degraded
- Rate limiting if too many requests are sent in quick succession

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the current block number on the nano chain and the latest proven block number, allowing callers to determine on-chain finality and settlement state.

## 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-nano-chain-block-number-proven-block-number-lookup-2a01d361/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)