chain_getBlock

Retrieves complete block information from Polkadot, including the block header, extrinsics, and justifications.

Why Polkadot? Build on the heterogeneous multi-chain protocol with $300M+ DeFi TVL and JAM supercomputer upgrade incoming with shared relay chain security, XCM cross-chain messaging, JAM upgrade targeting 1M TPS, and 2.1B DOT supply cap.

Use Cases

The chain_getBlock method is essential for:

• Block explorers - Display complete block information
• Chain analysis - Analyze block production patterns
• Transaction verification - Confirm extrinsic inclusion for cross-chain DeFi, parachain deployment, XCM interoperability, and DOT staking (8-10% APY)
• Data indexing - Build historical blockchain databases

Parameters

Parameter	Type	Required	Description
blockHash	String	No	Hex-encoded block hash. If omitted, returns latest block

Request

{
  "jsonrpc": "2.0",
  "method": "chain_getBlock",
  "params": ["0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"],
  "id": 1
}

Returns

Field	Type	Description
block	Object	Complete block data
block.header	Object	Block header information
block.header.parentHash	String	Hash of the parent block
block.header.number	String	Block number (hex-encoded)
block.header.stateRoot	String	Root of the state trie
block.header.extrinsicsRoot	String	Root of the extrinsics trie
block.extrinsics	Array	Array of extrinsics in the block
justifications	Array	Block justifications (if available)

Code Examples

cURL

# Get latest block
curl https://api-polkadot.n.dwellir.com/YOUR_API_KEY \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "chain_getBlock",
    "params": [],
    "id": 1
  }'

# Get specific block
curl https://api-polkadot.n.dwellir.com/YOUR_API_KEY \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "chain_getBlock",
    "params": ["0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"],
    "id": 1
  }'

JavaScript

import { ApiPromise, WsProvider } from '@polkadot/api';

const provider = new WsProvider('wss://api-polkadot.n.dwellir.com/YOUR_API_KEY');
const api = await ApiPromise.create({ provider });

// Get latest block
const latestHash = await api.rpc.chain.getBlockHash();
const latestBlock = await api.rpc.chain.getBlock(latestHash);

console.log('Latest block:', {
  number: latestBlock.block.header.number.toNumber(),
  hash: latestHash.toHex(),
  extrinsicsCount: latestBlock.block.extrinsics.length
});

// Get specific block
const blockHash = '0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3';
const block = await api.rpc.chain.getBlock(blockHash);
console.log('Block extrinsics:', block.block.extrinsics.length);

await api.disconnect();

Python

import requests
import json

def get_block(block_hash=None):
    url = 'https://api-polkadot.n.dwellir.com/YOUR_API_KEY'
    params = [block_hash] if block_hash else []

    payload = {
        'jsonrpc': '2.0',
        'method': 'chain_getBlock',
        'params': params,
        'id': 1
    }

    response = requests.post(url, json=payload)
    data = response.json()

    if 'error' in data:
        raise Exception(f"RPC Error: {data['error']}")

    return data['result']

# Get latest block
latest_block = get_block()
block_number = int(latest_block['block']['header']['number'], 16)
print(f'Latest block number: {block_number}')

# Get specific block
specific_block = get_block('0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3')
print(f"Extrinsics count: {len(specific_block['block']['extrinsics'])}")

Related Methods

• chain_getBlockHash - Get block hash by number
• chain_getHeader - Get block header only
• chain_getFinalizedHead - Get finalized block hash