blockchainBlockHeader

Overview

The blockchain.block.header method retrieves the block header at a specified height within the Bitcoin Cash blockchain via Rostrum Electrum. Optionally, it can also provide a merkle proof of the header's inclusion in the blockchain up to a specified checkpoint height (cp_height).

Parameters

Name	Type	Required	Description
height	integer	Yes	The height of the block.
cp_height	integer	No	Checkpoint height for the merkle proof, defaults to 0 (disabled).

Returns

Depending on the value of cp_height, the method returns either the raw block header as a hexadecimal string or a dictionary providing a merkle proof:

Field	Description
branch	An array of hashes in the merkle branch leading up to the checkpoint root.
header	The raw block header as a hexadecimal string.
root	The merkle root of all blockchain headers up to and including `cp_height`.

Example Result

If cp_height is 0:

{
  "header": "00000020a....61723"
}

## Request Example

```json cURL
curl --location 'https://api.tatum.io/v3/blockchain/node/rostrum-mainnet/' \
--header 'Content-Type: application/json' \
--header 'x-api-key: {API_KEY}' \
--data '{
    "method": "blockchain.block.header",
    "params": [5, 0],
    "id": 1,
    "jsonrpc": "2.0"
}'

// yarn add @tatumio/tatum

import { TatumSDK, Rostrum, Network } from "@tatumio/tatum";

const rostrum = await TatumSDK.init<Rostrum>({ network: Network.ROSTRUM_MAINNET });

const headerInfo = await tatum.rpc.getBlockHeader({
  height: 5,
  cp_height: 0
});

console.log(headerInfo);

await rostrum.destroy(); // Destroy Tatum SDK - needed for stopping background jobs