eth_getFilterChanges - Optimism

Example code for the eth_getFilterChanges json-rpc method. Сomplete guide on how to use eth_getFilterChanges json-rpc in GetBlock.io Web3 documentation.

This method retrieves changes for a filter created by eth_newFilter, eth_newBlockFilter, or eth_newPendingTransactionFilter. The type of data returned depends on the filter type: logs for log filters, block hashes for block filters, or transaction hashes for pending transaction filters.

Parameters

Parameter	Type	Description	Required
filterId	QUANTITY	The filter ID returned by filter creation methods.	Yes

Request Sample

cURL

curl --location 'https://go.getblock.us/<ACCESS_TOKEN>' \
--header 'Content-Type: application/json' \
--data '{
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x6c8b2705baa8223048745077aa6202d0"],
    "id": "getblock.io"
}'

Axios

const axios = require('axios');

const url = "https://go.getblock.io/<ACCESS-TOKEN>/";
const headers = { "Content-Type": "application/json" };

const payload = {
    jsonrpc: "2.0",
    method: "eth_getFilterChanges",
    params: ["0x6c8b2705baa8223048745077aa6202d0"],
    id: "getblock.io"
};

axios.post(url, payload, { headers })
    .then(response => {
        if (response.status === 200) {
            console.log("eth_getFilterChanges result:", response.data.result);
        } else {
            console.error("Error:", response.status, response.statusText);
        }
    })
    .catch(error => {
        console.error("Error:", error.response ? error.response.data : error.message);
    });

Request

import requests
import json

url = "https://go.getblock.io/<ACCESS-TOKEN>/"
headers = {
    "Content-Type": "application/json"
}
payload = {
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x6c8b2705baa8223048745077aa6202d0"],
    "id": "getblock.io"
}

response = requests.post(url, headers=headers, data=json.dumps(payload))

if response.status_code == 200:
    result = response.json().get("result")
    print("eth_getFilterChanges result:", result)
else:
    print("Error:", response.status_code, response.text)

Rust

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

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("Content-Type", "application/json".parse()?);

    let data = r#"{
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x6c8b2705baa8223048745077aa6202d0"],
    "id": "getblock.io"
}"#;

    let json: serde_json::Value = serde_json::from_str(&data)?;

    let request = client.request(reqwest::Method::POST, "https://go.getblock.us/<ACCESS_TOKEN>")
        .headers(headers)
        .json(&json);

    let response = request.send().await?;
    let body = response.text().await?;

    println!("{}", body);

    Ok(())
}

Response

A successful response returns the following:

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": [
        {
            "address": "0x4200000000000000000000000000000000000006",
            "topics": [
                "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
                "0x000000000000000000000000478946bcd4a5a22b316470f5486fafb928c0ba25",
                "0x0000000000000000000000009e3ed65340a913b96ba7b86d5d5876dde623946e"
            ],
            "data": "0x00000000000000000000000000000000000000000000000051d1a85fe050a203",
            "blockNumber": "0x9084924",
            "transactionHash": "0xb2adcd1e6d459f23c716c938c8e909f5b622dad31d213637eeccf9dac7d114bc",
            "transactionIndex": "0x3",
            "blockHash": "0x1dd45b1d28600add983fa7b999246f10898329781d3338841fdf721a3a542510",
            "blockTimestamp": "0x6a046c01",
            "logIndex": "0x22",
            "removed": false
        },
]
}

Response Parameters

• id: A unique request identifier, matching the id sent in the request body.

• jsonrpc: Specifies the use of JSON-RPC version 2.0.

• result: An array of log objects, block hashes, or transaction hashes, depending on filter type.

Use Case

The eth_getFilterChanges method is commonly used for:

• Event polling

• Real-time updates

• Filter-based monitoring

Error handling

Status Code	Error Message	Cause
404	Not Found	Missing or invalid ACCESS_TOKEN.
-32000	Invalid argument	The Address not 20 bytes or missing prefix block hash isn't accurate or incomplete keyword missing

Integration with Web3

Ethers.js

import { ethers } from "ethers";
const RPC_URL = "https://go.getblock.us/<ACCESS_TOKEN>";
const provider = new ethers.JsonRpcProvider(RPC_URL);
async function Call() {
  try {
     const result = await provider.send("eth_getFilterChanges",
     ["0x6c8b2705baa8223048745077aa6202d0"],);    
console.log("The result:", result);
    return result;
  } catch (error) {
    console.error("The error:", error);
    throw error;
  }
}

Viem

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

// Create Viem client with GetBlock
const client = createPublicClient({
  chain: optimism,
  transport: http('https://go.getblock.us/<ACCESS_TOKEN>'),
});

// Using the method through Viem
async function Call() {
    try {
        // Method-specific Viem implementation
        const result = await client.request({
          "method": "eth_getFilterChanges",
    "params": ["0x6c8b2705baa8223048745077aa6202d0"]
        });
        console.log('Result:', result);
        return result;
    } catch (error) {
        console.error('Viem Error:', error);
        throw error;
    }
}