수수료 위임 구현하기

import { ethers } from "ethers";

const SENDER_PRIVATE_KEY = process.env.SENDER_PRIVATE_KEY!;
const FEE_PAYER_PRIVATE_KEY = process.env.FEE_PAYER_PRIVATE_KEY!;

const provider = new ethers.JsonRpcProvider("https://api.test.stablenet.network");
const senderWallet = new ethers.Wallet(SENDER_PRIVATE_KEY, provider);
const feePayerWallet = new ethers.Wallet(FEE_PAYER_PRIVATE_KEY, provider);

// 1. 미서명 트랜잭션 빌드 (타입 0x16)
const unsignedTx = {
  type: 0x16,
  chainId: 8283,
  nonce: await provider.getTransactionCount(senderWallet.address),
  to: "0xRecipientAddress",
  value: ethers.parseEther("1.0"),
  gas: 30400n,
  maxFeePerGas: ethers.parseUnits("80000", "gwei"),
  maxPriorityFeePerGas: ethers.parseUnits("27600", "gwei"),
  feePayer: feePayerWallet.address,
  input: "0x",
  accessList: [],
};

// 2. 발신자 서명
const senderSig = await senderWallet.signTransaction(unsignedTx);

// 3. 수수료 지불자 확인 및 서명
const decoded = ethers.Transaction.from(senderSig);

// 서명 전 트랜잭션 확인 — 수수료 지불자는 가스 납부를 승인하는 것입니다
console.log("to:", decoded.to);
console.log("value:", ethers.formatEther(decoded.value), "WKRC");

const feePayerSig = await feePayerWallet.signTransaction(decoded);

// 4. 완전히 서명된 트랜잭션 브로드캐스트
const txResponse = await provider.broadcastTransaction(feePayerSig);
console.log("tx hash:", txResponse.hash);

const receipt = await txResponse.wait();
console.log("Confirmed in block", receipt.blockNumber);
console.log("Gas used:", receipt.gasUsed.toString());

tx hash: 0xabc...
Confirmed in block 1234567
Gas used: 21000

const feePayerBalance = await provider.getBalance(feePayerWallet.address);
console.log("Fee payer balance:", ethers.formatEther(feePayerBalance), "WKRC");