# EVM Chain Latest Block Query

> EVM Chain Latest Block Query is a paid API for AI agents from chain.cyberwarex.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns the latest block details (number, timestamp, age, base fee, gas used/limit) for any major EVM chain

## Facts

- Endpoint: GET https://chain.cyberwarex.com/block
- 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/evm-chain-latest-block-query-fb929b5b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2WKxgfGgzpQXdxvNiRp-h

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 evm-chain-latest-block-query-fb929b5b
```

Example prompt: What's the latest block on Base right now — give me the block number, timestamp, base fee, and how old it is in seconds?

## When to prefer this

Use this endpoint when you need the cheapest and simplest way to confirm an EVM chain is live, get the current block number or timestamp, or read the current base fee without needing full transaction or wallet data. Prefer this over wallet or transaction endpoints when you only need chain-level liveness or timing information.

## Known failure modes

- Unsupported chain name returns a validation error — only base, ethereum, arbitrum, optimism, polygon are accepted
- Network or RPC timeout if the underlying node is unreachable
- Payment required error (402) if the x402 payment header is missing or insufficient
- Stale data if the node is behind the chain tip, possibly inflating age_seconds

## How this service works

Latest block on any major EVM chain: block number, timestamp, age in seconds, base fee and gas used/limit. The cheapest possible liveness and chain-tip check for an agent: confirm a chain is progressing, timestamp an observation, or pick a block for a query.

## Output

Returns a JSON object containing the block hash, block number, chain name, chain ID, gas used, transaction count, gas limit, Unix timestamp, age in seconds since that block was mined, and base fee in gwei for the requested EVM chain.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "arbitrum",
        "optimism",
        "polygon"
       ],
       "type": "string",
       "default": "base",
       "description": "EVM chain to query."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "hash": {
       "type": "string"
      },
      "chain": {
       "type": "string"
      },
      "number": {
       "type": "integer"
      },
      "chain_id": {
       "type": "integer"
      },
      "gas_used": {
       "type": "integer"
      },
      "tx_count": {
       "type": "integer"
      },
      "gas_limit": {
       "type": "integer"
      },
      "timestamp": {
       "type": "integer"
      },
      "age_seconds": {
       "type": "integer"
      },
      "base_fee_gwei": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-chain-latest-block-query-fb929b5b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chain.cyberwarex.com](https://www.zero.xyz/host/chain.cyberwarex.com/llms.txt)