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POST
/
35848e183f3e3303c8cfeacbea831cab
eth_newBlockFilter
curl --request POST \
  --url https://bsc-mainnet.core.chainstack.com/35848e183f3e3303c8cfeacbea831cab \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "eth_newBlockFilter",
  "params": [],
  "id": 1
}
'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": [
    "<string>"
  ]
}
BNB API method that creates a filter that watches for new blocks on the blockchain. It returns a filter ID, which can be used to retrieve the results using the eth_getFilterChanges method. The eth_newBlockFilter method is useful for developers who must be notified of new blocks on the blockchain in real-time.
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Parameters

  • none

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Response

  • result — a hexadecimal string representing the ID of the newly created filter.
The filters created are stored on the blockchain client instance. The filter fill is automatically deleted if not polled within a certain time (5 minutes by default). Use the following methods with the filter ID:

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eth_newBlockFilter code examples

web3.eth.filterdeprecationNote 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);

const createFilter = async () => {
  try {
    const filterId = await provider.send('eth_newBlockFilter', []);
    console.log(filterId); // the filter ID returned by eth_newFilter
    return filterId
  } catch (error) {
    console.log(error);
  }
};

createFilter();

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Use case

One use case for eth_newBlockFilter in a simple DApp is to listen for new blocks and update the user interface with the latest block information. When the DApp starts, it creates a new filter using eth_newBlockFilter to listen for new blocks. When a new block is added to the blockchain, the filter is triggered, and the DApp retrieves the latest block information using a Web3 library.

Body

application/json
​
jsonrpc
string
default:2.0
​
method
string
default:eth_newBlockFilter
​
params
array
​
id
integer
default:1

Response

200 - application/json

The new filter ID.

​
jsonrpc
string
​
id
integer
​
result
string[]