chain_getHeader

Description

Returns the header for the latest block or a block specified by hash. Headers expose block number, state root, extrinsics root, and digest logs.

Parameters

Position	Type	Description
0 (optional)	string	Block hash. If omitted, the best block is returned.

Request Example

{
  "jsonrpc": "2.0",
  "method": "chain_getHeader",
  "params": [],
  "id": 1
}

Response Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "parentHash": "0x3f484429ad05365b32f643a9e825794961c1e6f92cde48a2c73935d7773dd5e1",
    "number": "0x9fbc28",
    "stateRoot": "0x1b983c37356b175bcf38dc1afcc8e31fa893e561f605fcad473697a68ac92169",
    "extrinsicsRoot": "0x783e75691edc604a3f13e1b5c558dd3ca5870ac07ce799c781713219a4a56224",
    "digest": {
      "logs": [
        "0x066175726120159b7a1100000000",
        "0x0452505352902bb51614ab3779fc4f4892aa8e21582a05a3162aef145209312f48c3b37fc7909618af06",
        "0x0466726f6e88015cd52a32691b3d44a3cef762382d728668dbee8c4509c697efe25708d5e6ffd400",
        "0x05617572610101809dd98345fce7c411d130f73a50b2e37d73efe027964dd63ce064275257cc1afb3192c7885ec1813c89350463bce9cd8b4f183b6e8cd779643ff4c476795e83"
      ]
    }
  }
}

Block 0x9fbc28 equals height 10,468,392 in decimal.

Code Examples

cURL

curl https://api-astar.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "chain_getHeader",
    "params": [],
    "id": 1
  }'

JavaScript (polkadot.js)

const api = await ApiPromise.create({ provider: new WsProvider('wss://api-astar.n.dwellir.com/YOUR_API_KEY') });
const header = await api.rpc.chain.getHeader();
console.log(`#${header.number} -> ${header.hash.toHex()}`);

Python (requests)

import requests, json

payload = {"jsonrpc": "2.0", "method": "chain_getHeader", "params": [], "id": 1}
resp = requests.post(
    "https://api-astar.n.dwellir.com/YOUR_API_KEY",
    headers={"Content-Type": "application/json"},
    data=json.dumps(payload)
)
print(resp.json()["result"])