POST
/
6df1a1b3061097e66349993a96b8e535
curl --request POST \
  --url https://aurora-mainnet.core.chainstack.com/6df1a1b3061097e66349993a96b8e535 \
  --header 'Content-Type: application/json' \
  --data '{
  "method": "eth_newFilter",
  "params": [
    {
      "fromBlock": "latest",
      "address": "0xC9BdeEd33CD01541e1eeD10f90519d2C06Fe3feB",
      "topics": [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
      ]
    }
  ],
  "id": 1,
  "jsonrpc": "2.0"
}'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": "<string>"
}

Aurora API method that generates a filter object based on the filter parameters. It returns a filter ID, which can be used to retrieve the filter results using the eth_getFilterChanges method. By creating a filter for specific events, developers can receive notifications when those events occur and use them to trigger actions in their applications.

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​
Parameters

  • object — the filter parameters:
    • fromBlock — (optional, default: latest) integer that specifies the starting block number from which the logs should be fetched.
    • toBlock — (optional, default: latest) integer that specifies the ending block number until which the logs should be fetched.
    • address — (optional) the contract address from which the logs should be fetched. It can be a single address or an array of addresses.
    • topics — (optional) an array of DATA topics. The event topics for which the logs should be fetched. It can be a single topic or an array of topics.
    • blockhash — (optional) the hash of the specific block. Limits logs to a specific block with a 32-byte hash value. It takes precedence over fromBlock and toBlock.

Possible tags forfromBlockandtoBlock

  • latest — the most recent block in the blockchain and the current state of the blockchain at the most recent block.
  • safe — the block that received justification from the beacon chain. Although this block could be involved in a chain reorganization, it would necessitate either a coordinated attack by the majority of validators or an instance of severe propagation latency.
  • finalized — the block accepted as canonical by more than 2/3 of the validators. A chain reorganization is extremely unlikely, and it would require at least 1/3 of the staked ETH to be burned.
  • earliest — the earliest available or genesis block.
  • pending — the pending state and transactions block. The current state of transactions that have been broadcast to the network but have not yet been included in a block.

See the default block parameter and How The Merge Impacts Ethereum’s Application Layer.

​
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 is automatically deleted if not polled within a certain time (5 minutes by default).

Use the following methods with the filter ID:

​
eth_newFilter 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);



const filter = {

  toBlock: 'latest',

  address: '0xC9BdeEd33CD01541e1eeD10f90519d2C06Fe3feB',

  topics: ['0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef']

};



const createFilter = async () => {

  try {

    const filterId = await provider.send('eth_newFilter', [filter]);

    console.log(filterId); // the filter ID returned by eth_newFilter

    return filterId

  } catch (error) {

    console.log(error);

  }

};



createFilter();

​
Use case

You can use eth_newFilter to create a filter for a specific action on a smart contract, for example, to monitor the transfer transactions from the Wrapped ETH token.

The idea is to create a filter using the eth_newFilter method to monitor an ERC-20 smart contract, WCRO in this case.

Body

application/json
​
method
string
default:eth_newFilter
​
params
object[]
​
id
integer
default:1
​
jsonrpc
string
default:2.0

Response

200 - application/json
The filter ID.
​
jsonrpc
string
​
id
integer
​
result
string