get_block_template - Monero

Example code for the get_block_template JSON-RPC method. Complete guide on how to use get_block_template JSON-RPC in GetBlock Web3 documentation.

This method returns a block blob and accompanying data that miners use to construct and submit a new block. The block reward is paid to the supplied wallet address.

Parameters

Parameter	Type	Required	Description
wallet_address	string	Yes	Address of the wallet that will receive the coinbase reward if the block is mined
reserve_size	unsigned int	Yes	Reserve size for extra bytes in the coinbase (often used by pools for nonce space)

Request Example

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "get_block_template",
    "params": {
        "wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns",
        "reserve_size": 60
    },
    "id": "getblock.io"
}'

JavaScript (Axios)

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "get_block_template",
    "params": {
        "wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns",
        "reserve_size": 60
    },
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));

Python (Requests)

import requests
import json

url = "https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "get_block_template",
    "params": {
        "wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns",
        "reserve_size": 60
    },
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)

Rust (Reqwest)

use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "get_block_template",
        "params": {
                "wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns",
                "reserve_size": 60
        },
        "id": "getblock.io"
});

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}

Response Example

{
    "id": "getblock.io",
    "jsonrpc": "2.0",
    "result": {
        "blockhashing_blob": "0e0eb6cdacf405fa7bdb281e0153d84cd55a3fcaa57c3e570f4a49f935850b5e3000000000aac4...",
        "blocktemplate_blob": "0e0eb6cdacf405fa7bdb281e0153d84cd55a3fcaa57c3e570f4a49f935850b5e3000000000aac4...",
        "difficulty": 294558564173,
        "expected_reward": 600000000000,
        "height": 912345,
        "prev_hash": "37155cae7d3aa8ca7dc8b9e69e0d1f64b5e3a8b1c2d9e4f5a6b7c8d9e0f1a2b3",
        "reserved_offset": 130,
        "status": "OK",
        "untrusted": false
    }
}

Response Parameters

Field	Type	Description
result.blockhashing_blob	string	Hex blob to feed into the proof-of-work hash function
result.blocktemplate_blob	string	Hex blob of the full block template
result.difficulty	unsigned int	Current network difficulty
result.expected_reward	unsigned int	Expected coinbase reward in atomic units
result.height	unsigned int	Height the block would be added at
result.prev_hash	string	Hash of the previous block
result.reserved_offset	unsigned int	Byte offset within the block where the reserve bytes are placed

Use Cases

• Mining pool block construction

• Solo mining client integration

• Testing mining software end-to-end

Error Handling

Status Code	Error Message	Cause
404	Not Found	Missing or invalid <ACCESS-TOKEN>
-32602	Invalid params	Request parameters are missing or malformed
429	Too Many Requests	Rate limit exceeded for your plan

SDK Integration

monero-javascript

import monerojs from 'monero-javascript';

const daemon = await monerojs.connectToDaemonRpc('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

// Most methods are exposed directly on the daemon client. For raw access:
const result = await daemon.getDaemonConnection().sendJsonRequest('get_block_template', {"wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns", "reserve_size": 60});
console.log(result);

monero-python

from monero.backends.jsonrpc import JSONRPCDaemon
from monero.daemon import Daemon

backend = JSONRPCDaemon(host='shared.eu-central-1.getblock.io', port=443, path='/<ACCESS-TOKEN>/', protocol='https')
daemon = Daemon(backend)

# For methods covered by the typed API, use the daemon attribute directly.
# For raw RPC access:
result = backend.raw_request('get_block_template', {"wallet_address": "44GBHzv6ZyQdJkjqZje6KLZ3xSyN1hBSFAnLP6EAqJtCRVzMzZmeXTC2AHKDS9aEDTRKmo6a6o9r9j86pYfhCWDkKjbtcns", "reserve_size": 60})
print(result)