# Block Header Info — Base, Ethereum, Arbitrum, Optimism, Polygon

> Block Header Info — Base, Ethereum, Arbitrum, Optimism, Polygon is a paid API for AI agents from biosfera.46-62-215-147.sslip.io, paid per call via x402, $0.001/call, status down (last checked 2026-10-02).

Returns block header details (hash, parent hash, timestamp, transaction count, gas used/limit, base fee, miner, size) for a given block number or 'latest' on five EVM chains.

## Facts

- Endpoint: GET https://biosfera.46-62-215-147.sslip.io/o/block-info?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/block-header-info-base-ethereum-arbitrum-optimism-polygon-c16ff607
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AmlLIWQMefqhshhES3Hek

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 block-header-info-base-ethereum-arbitrum-optimism-polygon-c16ff607
```

Example prompt: Can you fetch the block header for the latest block on Ethereum — I need the hash, timestamp, base fee, gas used, and transaction count?

## When to prefer this

Choose this endpoint when you need raw EVM block header metadata (hash, miner, gas, base fee, timestamp, size) for any of the five supported chains (Base, Ethereum, Arbitrum, Optimism, Polygon) by block number or 'latest', and do not need full transaction data or receipts. Ideal for monitoring chain activity, verifying block progression, auditing gas conditions, or enriching on-chain analytics pipelines.

## Known failure modes

- Invalid or out-of-range block number returns an error or empty result
- Unsupported chain value (not one of: base, ethereum, arbitrum, optimism, polygon) returns a validation error
- Block number in the future returns not-found or error
- Network or RPC connectivity issues for a specific chain may cause timeouts
- Malformed 'block' parameter (not matching pattern ^(latest|[0-9]{1,12})$) returns a schema validation error

## How this service works

Use when you need a block header on Base, Ethereum, Arbitrum, Optimism or Polygon: pass a block number or 'latest'. Returns hash, parent, timestamp, transaction count, gas used and limit, base fee, miner and size. Read-only public data.

## Output

Returns a JSON object with the block's hash, parent hash, timestamp (Unix), transaction count, gas used, gas limit, base fee per gas, miner address, and block size for the specified chain and block number or 'latest'.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "block"
     ],
     "properties": {
      "block": {
       "type": "string",
       "pattern": "^(latest|[0-9]{1,12})$"
      },
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "arbitrum",
        "optimism",
        "polygon"
       ],
       "type": "string"
      }
     },
     "additionalProperties": false
    }
   },
   "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/block-header-info-base-ethereum-arbitrum-optimism-polygon-c16ff607/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from biosfera.46-62-215-147.sslip.io](https://www.zero.xyz/host/biosfera.46-62-215-147.sslip.io/llms.txt)