chain_getBlock

Description#

Returns complete block information, including the header and SCALE-encoded extrinsics. Supplying a block hash lets you fetch historical blocks deterministically; omitting the parameter yields the latest block known to the node.

Parameters#

Parameter	Type	Required	Description
`blockHash`	string	No	Hex-encoded block hash. If omitted, the latest block is returned

Returns#

Field	Type	Description
`block.header`	object	Block header (parent hash, number, state root, extrinsics root, digest)
`block.extrinsics`	array	Array of SCALE-encoded extrinsic payloads
`justifications`	array \| null	Finality justifications, if present

Request Example#

{
  "jsonrpc": "2.0",
  "method": "chain_getBlock",
  "params": [
    "0x262e1b2ad728475fd6fe88e62d34c200abe6fd693931ddad144059b1eb884e5b"
  ],
  "id": 1
}

Response Example#

{
  "jsonrpc": "2.0",
  "result": {
    "block": {
      "header": {
        "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "number": "0x0",
        "stateRoot": "0x2a9c5fae68d226bfef7830398114196416ca1799ebb0099fdfa8b7b7ef19adf4",
        "extrinsicsRoot": "0x03170a2e7597b7b7e3d84c05391d139a62b157e78786d8c082f29dcf4c111314",
        "digest": {
          "logs": []
        }
      },
      "extrinsics": []
    },
    "justifications": null
  },
  "id": 1
}

The example above shows the Bifrost genesis block (#0), which contains no extrinsics.

Code Examples#

cURL
JavaScript

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

const request = async (hash) => {
  const params = hash ? [hash] : [];
  const response = await fetch('https://api-bifrost-polkadot.n.dwellir.com/YOUR_API_KEY', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'chain_getBlock',
      params,
      id: 1
    })
  });
  return (await response.json()).result;
};

const block = await request('0xd4b3a0e3b88b7c25215926bbf7c733f5c31e69c0c8c4b4a86d6ec3f3f086e95d');
console.log('Extrinsics count:', block.block.extrinsics.length);

Rust (subxt)#

use subxt::{config::substrate::SubstrateConfig, OnlineClient};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let api = OnlineClient::<SubstrateConfig>::from_url(
        "wss://api-bifrost-polkadot.n.dwellir.com/YOUR_API_KEY"
    ).await?;

    let hash = api.rpc().block_hash(None).await?.expect("best hash");
    let block = api.rpc().block(Some(hash)).await?.expect("block");
    println!("Block #{} has {} extrinsics", block.block.header.number, block.block.extrinsics.len());
    Ok(())
}

Usage Notes#

For production monitoring, pair chain_getBlock with chain_getFinalizedHead to avoid processing non-finalized blocks.
Extrinsics are returned as SCALE-encoded bytes. Decode them with the Bifrost metadata to extract calls such as timestamp.set, parachainsystem.set_validation_data, or SALP pallet operations.