# EVM Block Header Lookup

> EVM Block Header Lookup is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-29).

Retrieve block header data (hash, parent, timestamp, producer, gas metrics, base fee, transaction count) by block number, hex, or tag across 12 EVM chains

## Facts

- Endpoint: POST https://api.vextorium.com/evm-bloque-pago?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-block-header-lookup-4309ca36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_C5PAotWsIjqXDLY6DKsnI

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-block-header-lookup-4309ca36 -d '<json body>'
```

Example prompt: What are the block header details for the latest block on Base — give me the hash, producer, gas used, base fee, and transaction count.

## When to prefer this

Use this endpoint when you need structured block header metadata across any of 12 major EVM chains without running your own node. Especially useful for agents monitoring chain activity, validating block finality, auditing gas conditions at a specific block, or building blockchain analytics without direct RPC access. Supports convenient block tags (latest, safe, finalized) in addition to numeric or hex block references.

## Known failure modes

- Invalid block number or hex returns null or error response
- Unsupported chain value returns validation error
- Block tag not yet available (e.g. 'finalized' on a chain that doesn't support it) may return null
- Network timeout or RPC failure on the target chain returns an error
- Malformed request body returns schema validation error

## How this service works

Block header by number, hex or tag (latest, safe, finalized): hash, parent, time, producer, gas used and limit, base fee, transaction count and optionally the tx hashes. Works on Base, Ethereum, Arbitrum, Optimism, Polygon, BNB Chain, Avalanche, Gnosis, Linea, Scroll, Sonic and Unichain.

## Output

Returns a JSON object with: chain name (red), block hash, ISO-8601 timestamp (fecha), parent block hash (padre), block number (numero), gas used, block producer address, gas limit, gas usage percentage, block size in bytes, base fee in gwei, and transaction count. Optionally includes transaction hashes if incluir_tx is true.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "red": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon",
    "bnb",
    "avalanche",
    "gnosis",
    "linea",
    "scroll",
    "sonic",
    "unichain"
   ],
   "type": "string",
   "description": "Chain (default base)"
  },
  "numero": {
   "type": "string"
  },
  "incluir_tx": {
   "type": "boolean"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "red": "base",
  "hash": "0xb6ef30f50b707c8ba2bfff9b57a94ae64540545506de1ac20db38d0216ad80be",
  "fecha": "2026-10-02T20:04:57+00:00",
  "padre": "0x29759d0a3f90560c64e85952a84b1eef7d97f3d039e553cfeb9ceba69378e9a5",
  "numero": 52091075,
  "gas_usado": 41906338,
  "productor": "0x4200000000000000000000000000000000000011",
  "gas_limite": 400000000,
  "uso_gas_pct": 10.48,
  "tamano_bytes": 189493,
  "base_fee_gwei": 0.005,
  "transacciones": 156
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-block-header-lookup-4309ca36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)