# EVM Block Header by Number with Age and Gas Utilisation

> EVM Block Header by Number with Age and Gas Utilisation is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Returns a parsed EVM block header for a given block number and chain, including computed block age and gas utilisation percentage.

## Facts

- Endpoint: POST https://twin.unykorn.org/evm-block?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-block-header-by-number-with-age-and-gas-utilisation-cf6ee46c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Vt0pD8E-Cf7ur4umPu2fG

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-by-number-with-age-and-gas-utilisation-cf6ee46c -d '<json body>'
```

Example prompt: Can you fetch the block header for block 21000000 on Ethereum and tell me how old it is and what the gas utilisation was?

## When to prefer this

Use this endpoint when you need structured, pre-computed block metadata — specifically block age and gas utilisation — without having to manually calculate these from raw RPC data. It supports 10 major EVM chains in a single unified API, making it preferable over direct RPC calls when you need normalised output across chains or when you lack direct RPC access. Prefer this over raw eth_getBlockByNumber calls when gas utilisation and block age computations are needed out of the box.

## Known failure modes

- Invalid or non-existent block number returns an error response
- Unsupported chain name outside the allowed enum returns a validation error
- Payment failure via x402 protocol results in 402 response with no data
- Network timeout if the target EVM RPC is slow or unavailable
- Block number in the future returns an error or empty result

## How this service works

Block header by number, with age and gas utilisation worked out — Genesis402 / UnyKorn Operator Network

## Output

A JSON object containing the block header fields for the requested block on the specified EVM chain, including computed block age (how long ago it was mined) and gas utilisation (gas used divided by gas limit as a percentage), along with a payment receipt containing transaction hash, amount paid in USD, and a receipt ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "block": {
     "type": "string"
    },
    "chain": {
     "enum": [
      "ethereum",
      "base",
      "polygon",
      "arbitrum",
      "optimism",
      "bsc",
      "avalanche",
      "gnosis",
      "linea",
      "scroll"
     ],
     "type": "string"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "evm-block",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.003,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-block-header-by-number-with-age-and-gas-utilisation-cf6ee46c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)