starknet_blockHashAndNumber - STRK

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

This method returns both the hash and the number of the most recent accepted block in a single call. It is used to pin reads to a known tip.

Parameters

• None

Request

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": "starknet_blockHashAndNumber",
    "params": [],
    "id": "getblock.io"
}'

Axios

example.js

const axios = require('axios');

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'starknet_blockHashAndNumber',
    params: [],
    id: 'getblock.io'
}, {
    headers: { 'Content-Type': 'application/json' }
});

console.log(response.data.result);

Request

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'starknet_blockHashAndNumber',
        'params': [],
        'id': 'getblock.io'
    }
)

print(response.json())

Rust

example.rs

use reqwest::Client;
use serde_json::{json, Value};

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

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "starknet_blockHashAndNumber",
            "params": [],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "block_hash": "0x041b10c45dc3f39372f7b9409261cac9d880c5d75a5bb077d028db20b1bd76c4",
        "block_number": 700000
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	object	Object with block_hash and block_number

Use Cases

• Consistent Reads: Pin a batch of queries to one block hash and number

• Reorg Detection: Compare successive hashes at the same height

• Explorer Backends: Show the latest block hash and number together

• Snapshotting: Record the tip before a multi-call read

Error Handling

Error	Message	Description
63 / UNEXPECTED_ERROR	Unexpected error	The node failed to return the latest block
403 / RBAC: access denied	Access denied	The GetBlock access token is missing or incorrect