eth_getLogs | Ethereum

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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.

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Response

• array — an array of log objects that match the specified filter or an empty array if there have been no new events since the last poll:
  • 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.

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eth_getLogs code examples

const ethers = require("ethers");

// Create a ChainstackProvider instance for Ethereum mainnet
const chainstack = new ethers.ChainstackProvider("mainnet");

const getLogs = async () => {
  const latestBlock = await chainstack.getBlockNumber();
  const filter = {
    fromBlock: latestBlock - 100,
    toBlock: "latest",
    address: "0x4d224452801ACEd8B2F0aebE155379bb5D594381",
    topics: [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
    ],
  };
  const logs = await chainstack.getLogs(filter);
  console.log(logs);
};

getLogs();

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Block range limitations

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Use case

const { Web3 } = require("web3");
const NODE_URL = "CHAINSTACK_NODE_URL";
const web3 = new Web3(NODE_URL);

async function getTokenTransferLogs(contractAddress, tokenId) {
  try {
    const tokenIdHex = web3.utils.toHex(tokenId);
    const tokenIdTopic = web3.utils.padLeft(tokenIdHex, 64);

    const filter = {
      fromBlock: 19060000n,
      toBlock: 'latest',
      address: contractAddress,
      topics: ['0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef', null, null, tokenIdTopic]
      
    };    

    const logs = await web3.eth.getPastLogs(filter);

    const transferLogs = logs.map((log) => {
      const topics = log.topics;
      const fromAddress = topics[1];
      const formattedFromAddress = `0x${fromAddress.slice(26)}`;
      
      if (!web3.utils.toChecksumAddress(formattedFromAddress)) {
        throw new Error(`${formattedFromAddress} is an invalid address`);
      }

      const blockNumber = log.blockNumber;

      // Display a summary
      console.log(`Address ${formattedFromAddress} transferred the token ${tokenId} in block ${blockNumber}.`);
      
      return {
        fromAddress: formattedFromAddress,
        tokenId: tokenId,
        blockNumber: blockNumber
      };
    });

    return transferLogs;
  } catch (error) {
    throw new Error(`Error getting transfer logs: ${error.message}`);
  }
}

async function main() {
  const contractAddress = '0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D';
  const tokenId = 6750;
  
  try {
    const transferLogs = await getTokenTransferLogs(contractAddress, tokenId);
    console.log(transferLogs);
  } catch (error) {
    console.error(error.message);
  }
}

main();