starknet_syncing - STRK

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

This method returns an object describing sync progress while the node is catching up, or false once it is fully synced. It is used to confirm an endpoint is at the chain tip before relying on its data.

Parameters

This method does not require any parameters. Send the request with an empty params array.

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_syncing",
    "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_syncing',
    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_syncing',
        '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_syncing",
            "params": [],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

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

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "starting_block_hash": "0x041b10c45dc3f39372f7b9409261cac9d880c5d75a5bb077d028db20b1bd76c4",
        "starting_block_num": "0xa2c2a",
        "current_block_hash": "0x041b10c45dc3f39372f7b9409261cac9d880c5d75a5bb077d028db20b1bd76c4",
        "current_block_num": "0xab8a0",
        "highest_block_hash": "0x041b10c45dc3f39372f7b9409261cac9d880c5d75a5bb077d028db20b1bd76c4",
        "highest_block_num": "0xab8a0"
    }
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	boolean | object	false when synced, or a sync-status object (see fields below)

Result Object

Field	Type	Description
starting_block_num	string	Block the sync started from (felt)
current_block_num	string	Block currently processed (felt)
highest_block_num	string	Best known block on the network (felt)

Use Cases

• Readiness Gates: Hold traffic until the node reports it is fully synced

• Data Trust: Avoid serving stale reads from a node still catching up

• Monitoring: Alert when a node falls behind the network tip

• Failover Logic: Route away from nodes reporting an incomplete sync

Error Handling

Error	Message	Description
63 / UNEXPECTED_ERROR	Unexpected error	The node failed to report sync status
403 / RBAC: access denied	Access denied	The GetBlock access token is missing or incorrect