# chain-block-number

> chain-block-number is a paid API for AI agents from chain.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Returns the latest confirmed block number on Base, Ethereum, Arbitrum, Optimism, Polygon, or BSC.

## Facts

- Endpoint: GET https://chain.intel.rallylive.ca/chain/block-number?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/chain-block-number-9d464432
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RvGBfOMe_qalPJ4vV8iyE

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 chain-block-number-9d464432
```

Example prompt: What's the latest block number on Ethereum right now?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.01) real-time block height lookup across any of six major EVM chains without running your own RPC node. Ideal for agents that need to synchronize state, timestamp events relative to block height, or verify chain liveness. Prefer this over heavier block detail endpoints when you only need the block number, not full block data.

## Known failure modes

- Unsupported chain identifier returns an error or empty response
- Network connectivity issues to the RPC node may cause stale or failed responses
- Rate limiting or payment failure (x402) returns a 402 Payment Required response
- Chain name typo or unrecognized value may result in a null or error response

## How this service works

Latest block number on Base, Ethereum, Arbitrum, Optimism, Polygon or BSC. $0.01 per call.

## Output

Returns the latest confirmed block number (an integer) for the requested EVM-compatible chain — Base, Ethereum, Arbitrum, Optimism, Polygon, or BSC — read live from the network at query time.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/chain-block-number-9d464432/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chain.intel.rallylive.ca](https://www.zero.xyz/host/chain.intel.rallylive.ca/llms.txt)