eth_getFilterChanges | Tempo

Tempo API method that returns an array of logs or block/transaction hashes that occurred since the last poll. Tempo via Chainstack.

POST /

eth_getFilterChanges

cURL

curl --request POST \
  --url https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/ \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "eth_getFilterChanges",
  "params": [
    "0x..."
  ],
  "id": 1
}
'

import requests

url = "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/"

payload = {
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x..."],
    "id": 1
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({jsonrpc: '2.0', method: 'eth_getFilterChanges', params: ['0x...'], id: 1})
};

fetch('https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'jsonrpc' => '2.0',
    'method' => 'eth_getFilterChanges',
    'params' => [
        '0x...'
    ],
    'id' => 1
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_getFilterChanges\",\n  \"params\": [\n    \"0x...\"\n  ],\n  \"id\": 1\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_getFilterChanges\",\n  \"params\": [\n    \"0x...\"\n  ],\n  \"id\": 1\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_getFilterChanges\",\n  \"params\": [\n    \"0x...\"\n  ],\n  \"id\": 1\n}"

response = http.request(request)
puts response.read_body

200

{
  "jsonrpc": "<string>",
  "id": 123,
  "result": [
    "<unknown>"
  ]
}

Tempo API method that returns an array of logs or block/transaction hashes that occurred since the last poll. Used with filters created by eth_newFilter, eth_newBlockFilter, or eth_newPendingTransactionFilter.

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Parameters

• filterId — the filter ID returned from a filter creation method

Response

• result — array of changes since last poll:
  • For log filters: array of log objects
  • For block filters: array of block hashes
  • For pending transaction filters: array of transaction hashes

eth_getFilterChanges code examples

ethers.js

const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);

// pathUSD token address
const PATHUSD = "0x20c0000000000000000000000000000000000000";
const TRANSFER_TOPIC = ethers.id("Transfer(address,address,uint256)");

const pollFilter = async () => {
    // Create a log filter for Transfer events
    const filterId = await provider.send("eth_newFilter", [{
      address: PATHUSD,
      topics: [TRANSFER_TOPIC]
    }]);
    console.log(`Created filter: ${filterId}`);

    // Poll for changes every 2 seconds
    const interval = setInterval(async () => {
      const changes = await provider.send("eth_getFilterChanges", [filterId]);

      if (changes.length > 0) {
        console.log(`\nFound ${changes.length} new Transfer events:`);
        for (const log of changes) {
          console.log(`  Block ${parseInt(log.blockNumber, 16)}: ${log.transactionHash}`);
        }
      } else {
        console.log("No new changes...");
      }
    }, 2000);

    // Stop after 20 seconds
    setTimeout(async () => {
      clearInterval(interval);
      await provider.send("eth_uninstallFilter", [filterId]);
      console.log("\nFilter uninstalled");
    }, 20000);
  };

pollFilter();

from web3 import Web3
import time

node_url = "CHAINSTACK_NODE_URL"
web3 = Web3(Web3.HTTPProvider(node_url))

# pathUSD token address
PATHUSD = "0x20c0000000000000000000000000000000000000"
TRANSFER_TOPIC = web3.keccak(text="Transfer(address,address,uint256)").hex()

# Create a log filter
filter_result = web3.provider.make_request("eth_newFilter", [{
    "address": PATHUSD,
    "topics": [TRANSFER_TOPIC]
}])
filter_id = filter_result['result']
print(f"Created filter: {filter_id}")

# Poll for changes
try:
    for _ in range(10):
        changes_result = web3.provider.make_request("eth_getFilterChanges", [filter_id])
        changes = changes_result['result']

        if changes:
            print(f"\nFound {len(changes)} new Transfer events:")
            for log in changes:
                print(f"  Block {int(log['blockNumber'], 16)}: {log['transactionHash']}")
        else:
            print("No new changes...")

        time.sleep(2)
finally:
    web3.provider.make_request("eth_uninstallFilter", [filter_id])
    print("\nFilter uninstalled")

# First create a filter
curl -X POST "CHAINSTACK_NODE_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_newFilter",
    "params": [{"address": "0x20c0000000000000000000000000000000000000"}],
    "id": 1
  }'

# Then poll for changes using the returned filter ID
curl -X POST "CHAINSTACK_NODE_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x1"],
    "id": 1
  }'

Body

application/json

jsonrpc · string · default: 2.0

method · string · default: eth_getFilterChanges

params · any[]

Filter ID

id · integer · default: 1

Response

200 - application/json

Filter changes

jsonrpc · string

id · integer

result · any[]

Array of log objects or block hashes depending on filter type