typescript - 如何创建由一个账户签名但使用另一个账户支付的 Hedera 交易

Question

我正在尝试使用 Hedera JavaScript SDK 复制以下场景

• Bob 希望向 Hedera 网络发送一笔交易，但他没有 HBAR 来支付交易费用
• Alice 可以通过在 Hedera 网络上发送/执行 Bob 的交易来向 Bob 提供该服务，并支付相关的交易费用

此场景涉及以下步骤:

1. Bob 创建交易对象(例如 TokenCreateTransaction)
2. Bob 卡住并签署交易
3. Alice 收到 Bob 签名的交易并添加她的签名
4. Alice 执行交易并支付交易费用

您可以在下面看到实现:

import {
  AccountId,
  TokenCreateTransaction,
  TokenType,
  PrivateKey,
  Client,
} from "@hashgraph/sdk";

//  --- BOB (SIGNER account) ---
const BOB_ACCOUNTID = "0.0.5782085";
const BOB_PRIVATE_KEY = "";

// --- ALICE (PAYER account) ---
const ALICE_ACCOUNTID = "0.0.1079726";
const ALICE_PRIVATE_KEY = "";

async function main() {
  //  --- BOB (SIGNER account) ---
  const bobPrivateKey = PrivateKey.fromStringED25519(BOB_PRIVATE_KEY);
  const bobAccountId = AccountId.fromString(BOB_ACCOUNTID);
  const bobClient = Client.forTestnet().setOperator(
    bobAccountId,
    bobPrivateKey
  );

  // --- ALICE (PAYER account) ---
  const alicePrivateKey = PrivateKey.fromStringED25519(ALICE_PRIVATE_KEY);
  const aliceAccountId = AccountId.fromString(ALICE_ACCOUNTID);
  const aliceClient = Client.forTestnet().setOperator(
    aliceAccountId,
    alicePrivateKey
  );

  // 1. Bob creates the transaction object (e.g. a `TokenCreateTransaction`)
  const transaction = new TokenCreateTransaction()
    .setTokenName("New Token 123")
    .setTokenSymbol("NT123")
    .setTokenType(TokenType.FungibleCommon)
    .setInitialSupply(2000)
    .setTreasuryAccountId(bobAccountId);

  // 2. Bob freezes and signs the transaction
  const frozenTx = await transaction.freezeWith(bobClient);
  const signedTx = await frozenTx.sign(bobPrivateKey);

  // 3. Alice receives the signed transaction from Bob and adds her signature
  const aliceSignedTx = await signedTx.sign(alicePrivateKey);

  // 4. Alice executes the transaction and pays for the transaction fees
  const txResponse = await aliceSignedTx.execute(aliceClient);
  const receipt = await txResponse.getReceipt(aliceClient);
  console.log("TransactionId: " + txResponse.transactionId);
  console.log("Transaction status: " + receipt.status.toString());
  console.log("Created tokenId: " + receipt.tokenId);

  process.exit();
}

main();

当 Bob 卡住交易时就会出现问题，因为某些交易属性会被 SDK 自动修改。具体来说，transactionId 和 operatorAccountId 属性是根据卡住帐户设置的，因此将 Bob 指定为交易的付款人。

因此，即使 Alice 在流程结束时执行了交易，付款人帐户实际上是 Bob。

您可以在此处看到结果，其中 Bob (AccountId 0.0.5782085) 是付款人帐户:https://hashscan.io/testnet/transaction/1698410500.114199003

我们如何确保 Alice 是支付交易费用的人，特别是当 Bob 是第一个卡住交易费用的人时？任何想法将不胜感激。

Answer 1

经过多次尝试，我找到了解决问题的方法。

Bob创建交易时，需要设置transactionId使用setTransactionId()方法如下图:

const transaction = new TokenCreateTransaction()
  .setTransactionId(transactionId)

transactionId参数在此过程中至关重要。 Bob 必须使用 Alice 的 AccountId 创建它，以指定 Alice 作为交易的付款人。为了生成它，Bob 可以利用 generate()方法来自 TransactionId class 。确保在代码开头导入该类:

import { TransactionId } from "@hashgraph/sdk";

const transactionId = TransactionId.generate(aliceAccountId)

这样，我们可以确保Bob发起、卡住和签署交易，同时指定Alice作为支付交易费用的付款账户。

Important: this flow requires that Bob knows Alice's AccountId before creating the transaction.

这里是所有更新的代码(只添加了2行，注释为:<--- New Line):

import {
  AccountId,
  TokenCreateTransaction,
  TokenType,
  PrivateKey,
  Client,
  TransactionId, // <--- New Line
} from "@hashgraph/sdk";

//  --- BOB Account (SIGNER) ---
const BOB_ACCOUNTID = "0.0.5782085";
const BOB_PRIVATE_KEY = "";

// --- ALICE Account (PAYER) ---
const ALICE_ACCOUNTID = "0.0.1079726";
const ALICE_PRIVATE_KEY = "";

async function main() {
  //  --- BOB (SIGNER account) ---
  const bobPrivateKey = PrivateKey.fromStringED25519(BOB_PRIVATE_KEY);
  const bobAccountId = AccountId.fromString(BOB_ACCOUNTID);
  const bobClient = Client.forTestnet().setOperator(
    bobAccountId,
    bobPrivateKey
  );

  // --- ALICE (PAYER account) ---
  const alicePrivateKey = PrivateKey.fromStringED25519(ALICE_PRIVATE_KEY);
  const aliceAccountId = AccountId.fromString(ALICE_ACCOUNTID);
  const aliceClient = Client.forTestnet().setOperator(
    aliceAccountId,
    alicePrivateKey
  );

  // 1. Bob creates the transaction object (e.g. a `TokenCreateTransaction`) 
  // and sets a specific transactionId to designate Alice as the payer account 
  const transaction = new TokenCreateTransaction()
    .setTokenName("New Token 123")
    .setTokenSymbol("NT123")
    .setTokenType(TokenType.FungibleCommon)
    .setInitialSupply(2000)
    .setTreasuryAccountId(bobAccountId)
    .setTransactionId(TransactionId.generate(aliceAccountId)); // <--- New Line

  // 2. Bob freezes and signs the transaction
  const frozenTx = await transaction.freezeWith(bobClient);
  const signedTx = await frozenTx.sign(bobPrivateKey);

  // 3. Alice receives the signed transaction from Bob and adds her signature
  const doubleSignedTx = await signedTx.sign(alicePrivateKey);

  // 4. Alice executes the transaction and pays for the transaction fees
  const txResponse = await doubleSignedTx.execute(aliceClient);
  const receipt = await txResponse.getReceipt(aliceClient);
  console.log("TransactionId: " + txResponse.transactionId);
  console.log("Transaction status: " + receipt.status.toString());
  console.log("Created tokenId: " + receipt.tokenId);

  process.exit();
}

main();

您可以在此处看到结果，其中 Alice (AccountId 0.0.1079726 ) 是付款人帐户:https://hashscan.io/testnet/transaction/1698423106.148047003

希望对大家有帮助!