Account Update

Fee Delegation

Import the ethers and @kaiachain/viem-ext packages to add kaia features on web3

Set up sender and fee payer wallets using createWalletClient, configured with the Kairos chain, an HTTP transport, and the sender’s private key converted to an account.

Uses the ethers library to compute the compressed public key from the sender’s private key. This public key will be used to update the sender’s account key on the Kaia blockchain.

Create a transaction request for a value transfer using prepareTransactionRequest, specifying the sender’s account, recipient address, value to transfer (0 KLAY in this example), transaction type (TxType.FeeDelegatedAccountUpdate) and the key field specifies the new public key with type AccountKeyType.Public.

Signing the transaction with the wallet client’s signTransaction method, and log the transaction hash.

The fee payer signs the already-signed transaction from the sender with function signTransactionAsFeePayer, agreeing to pay the transaction fees.

Sends the fully signed, fee-delegated transaction (signed by both sender and fee payer) to the Kairos blockchain network using the kaia_sendRawTransaction method, returning the transaction hash or response from the network.

TxTypeFeeDelegatedAccountUpdate.js


import { AccountKeyType, createWalletClient, http, kairos, privateKeyToAccount, TxType } from "@kaiachain/viem-ext";
import { ethers } from "ethers";
const senderWallet = createWalletClient({
  chain: kairos,
  transport: http(),
  account: privateKeyToAccount("0x0e4ca6d38096ad99324de0dde108587e5d7c600165ae4cd6c2462c597458c2b8")
})
const feePayerWallet = createWalletClient({
  chain: kairos,
  transport: http(),
  account: privateKeyToAccount("0x9435261ed483b6efa3886d6ad9f64c12078a0e28d8d80715c773e16fc000cff4")
});
async function main() {
  const pub = ethers.SigningKey.computePublicKey("0x0e4ca6d38096ad99324de0dde108587e5d7c600165ae4cd6c2462c597458c2b8", true);
  const txRequest = await senderWallet.prepareTransactionRequest({
    account: senderWallet.account,
    to: "0x70997970c51812dc3a010c7d01b50e0d17dc79c8",
    value: 0,
    type: TxType.FeeDelegatedAccountUpdate,
    key: {
      type: AccountKeyType.Public,
      key: pub,
    },
  });
  const signedTx = await senderWallet.signTransaction(txRequest);
  console.log("signedTx", signedTx)
  const feePayerSignedTx = await feePayerWallet.signTransactionAsFeePayer(signedTx);
  const res = await feePayerWallet.request({
    method: "kaia_sendRawTransaction",
    params: [feePayerSignedTx],
  });
  console.log("fee delegated acount update tx", res);
};
main();

output


❯ js TxTypeFeeDelegatedAccountUpdate.js
signedTx 0x21f88e82095785066720b30082cd1494a2a8854b1802d8cd5de631e690817c253d6a9153a302a103dc9dccbd788c00fa98f7f4082f2f714e799bc0c29d63f04d48b54fe6250453cdf847f8458207f5a0d3251e52a53fae1891b0fdc8e0b5ecf2a7f2841d9f8fa8cf68d8bc037dd1e44fa06ab24023150e38fb03e431efbd5328a3f2f69ce7f2f98eb13c0846fb8ff8b0f1   
fee delegated acount update tx 0x59147c1dbbea0aab51fd4d46484d516a50eeca9266dd417281e18f3b686c0fd9