POST
/
35848e183f3e3303c8cfeacbea831cab
eth_getFilterChanges
curl --request POST \
  --url https://bsc-mainnet.core.chainstack.com/35848e183f3e3303c8cfeacbea831cab \
  --header 'Content-Type: application/json' \
  --data '{
  "jsonrpc": "2.0",
  "method": "eth_getFilterChanges",
  "params": [
    "0xbdc5b4b99ca699e1d734fc4202afee79"
  ],
  "id": 1
}'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": [
    "<string>"
  ]
}
BNB API polling method used to retrieve updates from a filter. A filter is an object used to track changes to the state of the blockchain.
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Filters can be created using one of the following methods: After creating a filter using one of the available methods, the resulting filter ID can be used to fetch changes by calling the eth_getFilterChanges method.
DisclaimerNote that the default interactive example in this page will not work as the filter will be expired.To test eth_getFilterChanges in this page, first create a new filter using one of the following:Then use the fresh filter ID as the parameter for eth_getFilterChanges.

​
Parameters

  • string — the filter ID of the filter for which you want to retrieve the changes

​
Response

  • array — an array that represents the changes that have occurred on the blockchain since the last time the filter was polled:
    • For filters created with eth_newBlockFilter:
      • blockHash — the hashes of the new blocks since the last time the filter was polled.
    • For filters created with eth_newPendingTransactionFilter:
      • transactionHash — the hashes identifying new pending transactions since the last time the filter was polled.
    • For filters created with eth_newFilter, the following event logs:
      • address — the contract address from which the event originated.
      • topics — an array of 32-byte data fields containing indexed event parameters.
      • data — the non-indexed data that was emitted along with the event.
      • blocknumber — the block number in which the event was included. null if it is pending.
      • transactionhash — the hash of the transaction that triggered the event. null if pending.
      • transactionindex — the integer index of the transaction within the block’s list of transactions. null if it is pending.
      • blockhash — the hash of the block in which the event was included. null if it is pending.
      • logindex — the integer identifying the index of the event within the block’s list of events. null if pending.
      • removed — the boolean value indicating if the event was removed from the blockchain due to a chain reorganization. True if the log was removed. False if it is a valid log.

​
eth_getFilterChanges code examples

Note that the web3.eth.filter methods have been deprecated and replaced with the web3.eth.subscribe in web3.js. See web3.js subscriptions.
const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);

async function getFilterChanges(filter) {
  try {
    const changes = await provider.send('eth_getFilterChanges', [filter]);
    console.log(changes); // Log the with the new data
  } catch (err) {
    console.error(err); // Handle errors that may occur
  }
}

const filterId =  '0x4e7ef166cd43f188b0f8f9e218966a8f' //'YOUR_FILTER_iD'
getFilterChanges(filterId)

​
Use case

The eth_getFilterChanges method can poll a filter to periodically retrieve new data. You can, for example, create a blocks filter using eth_newBlockFilter and periodically poll it to get new blocks.

Body

application/json

Response

200 - application/json

The filter changes.

The response is of type object.