eth_getFilterChanges - BSC

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

The eth_getFilterChanges method returns an array of logs or block hashes that have occurred since the last poll for the given filter on the BNB Smart Chain.

Parameters

Parameter	Type	Required	Description
filterId	string	Yes	Filter ID from eth_newFilter or eth_newBlockFilter

Request Example

cURL

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_getFilterChanges",
    "params": ["0x1"],
    "id": "getblock.io"
}'

JavaScript (Axios)

example.js

const axios = require('axios');

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

const payload = {
    jsonrpc: '2.0',
    method: 'eth_getFilterChanges',
    params: ['0x1'],
    id: 'getblock.io'
};

axios.post(url, payload, {
    headers: { 'Content-Type': 'application/json' }
})
.then(response => console.log(response.data))
.catch(error => console.error(error));

Python

example.py

import requests

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

payload = {
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x1"],
    "id": "getblock.io"
}

response = requests.post(url, headers={"Content-Type": "application/json"}, json=payload)
print(response.json())

Rust

main.rs

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": "eth_getFilterChanges",
        "params": ["0x1"],
        "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

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

Response Parameters

Parameter	Type	Description
result	array	Array of log objects or block hashes

Use Cases

• Poll for new events on BSC

• Monitor BEP-20 token transfers

• Track PancakeSwap swaps

• Build event-driven applications

When possible, prefer provider-native event listening (SDK event listeners or websocket subscriptions) instead of manual polling for better efficiency and lower latency.

Error Handling

Error Code	Description
-32602	Invalid filter ID
-32603	Internal error

SDK Integration

Ethers.js

const { ethers } = require('ethers');

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

// Use event listeners instead of manual polling
const usdtContract = new ethers.Contract(address, abi, provider);
usdtContract.on('Transfer', (from, to, amount) => {
    console.log('Transfer:', from, to, amount);
});

Viem

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

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

// Use watchContractEvent for real-time monitoring