# Postandshare Multi-Chain Block Number Lookup

> Postandshare Multi-Chain Block Number Lookup is a paid API for AI agents from api.postandshare.net, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-28).

Returns the current (latest) block number for a specified EVM-compatible blockchain network (Base, Ethereum, Arbitrum, or Polygon)

## Facts

- Endpoint: GET https://api.postandshare.net/v1/chain/block-number?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/postandshare-multi-chain-block-number-lookup-52fa2ab2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tWT8MGAgZMCHNkHybhpId

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 postandshare-multi-chain-block-number-lookup-52fa2ab2
```

Example prompt: What's the current block number on Base right now?

## When to prefer this

Choose this endpoint when you need a quick, cheap ($0.001 USDC) on-chain block number read across Base, Ethereum, Arbitrum, or Polygon without running your own node. Ideal for agents that need to confirm chain liveness, benchmark sync status, or anchor timestamps to block heights. Prefer this over running a full RPC node when you just need a lightweight, pay-per-call lookup.

## Known failure modes

- Invalid or unsupported network name returns an error — only 'base', 'ethereum', 'arbitrum', 'polygon' are accepted
- Network RPC node temporarily unavailable returns a 5xx error
- Payment failure (x402 USDC payment not accepted) blocks the request
- Rate limiting or quota exceeded if too many calls made rapidly

## How this service works

x402 pay-per-call data endpoints for AI agents: multi-chain reads (Base, Ethereum, Arbitrum, Polygon) and Nigerian reference data. Format/reference validation only — no personal data, no identity-database lookup.

## Output

Returns the latest block number (an integer representing the current chain height) for the requested EVM network. This tells you how many blocks have been confirmed on the chain up to this moment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "network": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "polygon"
   ],
   "type": "string",
   "description": "Chain to read: base (default), ethereum, arbitrum, polygon"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/postandshare-multi-chain-block-number-lookup-52fa2ab2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.postandshare.net](https://www.zero.xyz/host/api.postandshare.net/llms.txt)