How to set the transaction fee in function "sendTransaction"

[klcwong]

Hello guys.

I am trying to create ETH transaction by using ethers.js.

I can create the transaction by using the below code:

const getEthAddress = async (mnemonic, node) => {
  const network = "goerli";
  const provider = new ethers.getDefaultProvider(network, {
    etherscan: ETHERSCAN_API_KEY,
  });
  const address = "0x0ce58fe12D080daB4B9995259E3b06a81654694b";

  // const wallet = ethers.Wallet.fromMnemonic(mnemonic, `m/44'/60'/0'/0/${node}`); // for live
  const wallet = ethers.Wallet.fromMnemonic(mnemonic, `m/44'/1'/0'/0/${node}`); // for testnet
  // 0xA85EA4a812577fe2Cf9D4B27bB32faF3Ee7a6c14

  const walletSigner = wallet.connect(provider);

  const gasPrice = await provider.getGasPrice();
  const gasPriceNum = ethers.utils.formatUnits(gasPrice);

  const tx = await walletSigner.sendTransaction({
    to: address,
    value: ethers.utils.parseEther("0.001"),
    gasPrice: gasPrice,
  });

  return tx;
};

This is the transaction:
https://goerli.etherscan.io/tx/0x371129df043df098bd63e569f3f012b9f666a6dd928163bc6adb34cdeeef3889

However, I cannot control the transaction fee (0.000031499999916 Ether) (not GAS). How can I set the transaction fee in function sendTransaction? Thank you!

[ricmoo]

Keep in mind gasPrice is deprecated and should not be used. You are seeing legacy behaviour since you are passing the gasPrice property.

You should use the maxFeePerGas and maxPriorityFeePerGas properties.

The number is multiplied by the gasLimit and that is the maximum transaction fee.

However, once the block is mined, the fee will likely be lower; the EIP-1559 protocol determines the effective fee per gas, and the actual gas used will be multiplied by that, which is the actual transaction fee.

[klcwong]

Keep in mind gasPrice is deprecated and should not be used. You are seeing legacy behaviour since you are passing the gasPrice property.

You should use the maxFeePerGas and maxPriorityFeePerGas properties.

The number is multiplied by the gasLimit and that is the maximum transaction fee.

However, once the block is mined, the fee will likely be lower; the EIP-1559 protocol determines the effective fee per gas, and the actual gas used will be multiplied by that, which is the actual transaction fee.

Sorry for late reply.
Thank you!

Could I create a transaction and it contains more than 1 sender address? Like bitcoin

[ricmoo]

No, Bitcoin uses UTXOs, which requires multiple senders to send fragments of a UTXO back as change.

In Ethereum, accounts are used so the amount sent is explicit without the need for change.