eth_syncing - Ethereum

Example code for the eth_syncing JSON RPC method. Сomplete guide on how to use eth_syncing JSON RPC in GetBlock Web3 documentation.

This method returns an object with sync status data when the node is catching up to the chain tip, or false when the node is fully synced. Managed RPC endpoints typically return false unless a specific backend node is currently mid-sync.

Parameters

This method takes no parameters.

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": "eth_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: 'eth_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': 'eth_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": "eth_syncing",
            "params": [],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;
    
    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": false
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	boolean or object	false if fully synced, or an object with startingBlock, currentBlock, highestBlock (hex) if catching up

Use Cases

• Node Freshness Verification: Confirm a node is at chain tip before treating its reads as canonical

• Sync Progress Monitoring: Track a self-hosted node's catch-up progress via the currentBlock / highestBlock fields

• Failover Decisioning: Skip a syncing backend and route to a fully-synced one at the load balancer level

Error Handling

Error Code	Message	Description
-32603	Internal error	Node failed to determine its sync state

Web3 Integration

Ethers.js

ethers-example.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const syncStatus = await provider.send('eth_syncing', []);
if (syncStatus === false) {
    console.log('Node is fully synced');
} else {
    console.log('Syncing:', syncStatus);
}

Viem

viem-example.js

import { createPublicClient, http } from 'viem';
import { mainnet } from 'viem/chains';

const client = createPublicClient({
    chain: mainnet,
    transport: http('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/'),
});

const syncStatus = await client.request({ method: 'eth_syncing' });
if (syncStatus === false) {
    console.log('Node is fully synced');
} else {
    console.log('Syncing:', syncStatus);
}