eth_getFilterChanges

Polling method for a filter, which returns an array of events that have occurred since the last poll on the Unichain network.

Parameters

• id (string, required): The filter ID returned from eth_newFilter, eth_newBlockFilter, or eth_newPendingTransactionFilter

Returns

An array containing different data types depending on the filter type:

For log filters (eth_newFilter):

Array of log objects with:

• address (string): Address from which this log originated
• topics (array of strings): Array of 0 to 4 32-byte DATA topics
• data (string): Contains non-indexed arguments of the log
• blockNumber (string): Block number where this log was included
• blockHash (string): Hash of the block where this log was included
• transactionHash (string): Hash of the transaction that created this log
• transactionIndex (string): Transaction index position in the block
• logIndex (string): Integer of the log index position in the block
• removed (boolean): true when the log was removed due to a chain reorganization

For block filters (eth_newBlockFilter):

Array of 32-byte block hashes for blocks that were newly created

For pending transaction filters (eth_newPendingTransactionFilter):

Array of 32-byte transaction hashes for transactions that entered the pending state

Implementation Example

cURL

curl -X POST https://api-unichain-mainnet.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x16"],
    "id": 1
  }'

JavaScript

const response = await fetch('https://api-unichain-mainnet.n.dwellir.com/YOUR_API_KEY', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'eth_getFilterChanges',
    params: ['0x16'],
    id: 1
  })
});

const data = await response.json();
console.log(data.result);

Python

import requests
import json

url = 'https://api-unichain-mainnet.n.dwellir.com/YOUR_API_KEY'
headers = {'Content-Type': 'application/json'}
payload = {
    "jsonrpc": "2.0",
    "method": "eth_getFilterChanges",
    "params": ["0x16"],
    "id": 1
}

response = requests.post(url, headers=headers, data=json.dumps(payload))
data = response.json()
print(data['result'])

Response Example

For log filters:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "address": "0x1234567890abcdef1234567890abcdef12345678",
      "topics": [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
      ],
      "data": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
      "blockNumber": "0x1b4",
      "blockHash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
      "transactionHash": "0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321",
      "transactionIndex": "0x1",
      "logIndex": "0x0",
      "removed": false
    }
  ]
}

For block filters:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
    "0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321"
  ]
}

Notes

• This method only returns changes that occurred since the last poll
• Filters timeout if not accessed within a certain time period (typically 5 minutes)
• The first call to eth_getFilterChanges returns all events since filter creation
• Subsequent calls return only new events since the previous call
• Use eth_getFilterLogs to retrieve all accumulated logs regardless of polling

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Need help? Contact our support team or check the Unichain documentation.