1. 导言
本教程将指导您使用 Kaia SDK (ethers-ext) 创建一个简单的服务器-客户端示例,以演示费用委托价值转移交易如何在 Kaia 上运行。 教程和示例代码已在 Kairos 测试网上进行了测试。
2. 如何进行费用委托
让我们简要了解一下费用委托的运作方式。
2.1 发送方签署交易
发送方 "在发送交易之前,应始终签署交易。
要签署事务,可使用 signTransaction 用给定的私钥签署事务。
const senderAddress = "SENDER_ADDRESS";
const senderPrivateKey = "SENDER_PRIVATE_KEY";
const recieverAddr = "RECEIVER_ADDRESS";
// Create a new transaction
type:TxType.FeeDelegatedValueTransfer,
value: parseKaia("0.01"),
tx = await senderWallet.populateTransaction(tx);
const senderTxHashRLP = await senderWallet.signTransaction(tx);
console.log("senderTxHashRLP", senderTxHashRLP);
如果没有错误,那么 senderTxHashRLP
将有一个已签名的事务,该事务由 senderPrivateKey
签名。
现在,您需要将 senderTxHashRLP
发送给缴费人。 实施的方法有很多种。 在本教程中,我们将提供一个简单的服务器-客户端代码,作为向缴费人发送 "senderTxHashRLP "的示例。
2.2 付款人签署交易
当 "付费方 "收到 "发送方 TxHashRLP "时,"付费方 "会再次用自己的私钥对 "发送方 TxHashRLP "进行签名,并将交易发送给 Kaia。 下面的代码片段说明了这一过程。
sendTransactionAsFeePayer 方法在发送交易前用给定的付费者私钥对交易进行签名。 运行代码前,请用实际值替换 "FEEPAYER_ADDRESS "和 "PRIVATE_KEY"。
请注意,当缴费人代表发件人向 Kaia 提交交易时,"senderTxHashRLP "类型必须是 "FeeDelegatedValueTransfer "类型的交易。
const feePayerAddress = "FEEPAYER_ADDRESS";
const feePayerPrivateKey = "FEEPAYER_PRIVATE_KEY"
const sentTx = await feePayerWallet.sendTransactionAsFeePayer(senderTxHashRLP);
console.log("sentTx", sentTx);
const rc = await sentTx.wait();
console.log("receipt", rc);
.on('transactionHash', function(hash){
.on('receipt', function(receipt){
.on('error', console.error); // 如果出错,第二个参数就是收据。
3. 收费委托的简单服务器和客户端
让我们用上述费用委托代码编写一个简单的服务器和客户端。
3.1 环境设置
我们将使用 npm init -y
设置 Node.js 项目,并安装 ethers-ext
mkdir feedelegation_server
npm install - -save @kaiachain/ethers-ext@^1.2.0 ethers@6
@kaiachain/ethers-ext@^1.2.0 建议使用节点 22 或更高版本
3.2 发件人客户端
首先,我们要编写一个sender_client.js
,如下所示。
在示例中,请用实际值替换"SENDER_ADDRESS"、
"SENDER_PRIVATEKEY "和`"RECEIVER_ADDRESS"。
const { Socket } = require("net");
const client = new Socket();
const { Wallet, TxType, parseKaia } = require("@kaiachain/ethers-ext").v6;
const ethers = require("ethers");
const senderAddress = "SENDER_ADDRESS";
const senderPrivateKey = "SENDER_PRIVATE_KEY";
const recieverAddr = "RECEIVER_ADDRESS";
const sendFeeDelegateTx = async () => {
const provider = new ethers.JsonRpcProvider("https://public-en-kairos.node.kaia.io");
const senderWallet = new Wallet(senderPrivateKey, provider);
// Create a new transaction
type:TxType.FeeDelegatedValueTransfer,
value: parseKaia("0.01"),
tx = await senderWallet.populateTransaction(tx);
const senderTxHashRLP = await senderWallet.signTransaction(tx);
console.log("senderTxHashRLP", senderTxHashRLP);
throw new Error("Failed to generate raw transaction");
} // Send signed raw transaction to fee payer.
client.connect(1337, "127.0.0.1", () => {
console.log("Connected to fee delegated service");
client.write(senderTxHashRLP);
client.on("data", (data) => {
console.log("Received data from server:", data.toString();
client.on("error", (error) => {
console.error("Connection error:", error);
client.on("close", () => {
console.log("Connection closed");
console.error("Transaction error:", error);
上述代码使用 "senderPrivateKey "对费用委托价值转移交易进行签名,并将签名后的 "senderTxHashRLP "发送至费用支付方的服务器,该服务器运行于 "127.0.0.1 "上的 "1337 "端口,即 localhost。
3.3 缴费者服务器
现在,让我们编写缴费人服务器 feepayer_server.js
,用 feePayerPrivateKey
对接收到的 senderTxHashRLP
进行签名,并将其发送到 Kairos 测试网。
在下面的示例中,请用实际值替换"FEEPAYER_ADDRESS "和
"FEEPAYER_PRIVATEKEY"。
const { createServer } = require("net");
const { Wallet, JsonRpcProvider } = require("@kaiachain/ethers-ext").v6;
const feePayerAddress = "FEEPAYER_ADDRESS";
const feePayerPrivateKey = "FEEPAYER_PRIVATE_KEY";
const provider = new JsonRpcProvider("https://public-en-kairos.node.kaia.io");
const feePayerWallet = new Wallet(feePayerPrivateKey, provider);
const feePayerSign = async (senderTxHashRLP, socket) => {
const sentTx = await feePayerWallet.sendTransactionAsFeePayer(senderTxHashRLP);
console.log("sentTx", sentTx);
const rc = await sentTx.wait();
console.log("receipt", rc);
if (rc.transactionHash) {
socket.write(`Tx hash: ${rc.transactionHash}\n`);
socket.write(`Sender Tx hash: ${rc.senderTxHash || ""}\n`);
console.error("Error in feePayerSign:", error);
socket.write(`Error: ${error.message}\n`);
} }; const server = createServer.
const server = createServer(function (socket) {
console.log("Client is connected ...");
socket.write("This is fee delegating service");
socket.write("Fee Payer is " + feePayerAddress);
socket.on("data", function (data) {
console.log("Received data from client:", data.toString());
feePayerSign(data.toString(), socket);
socket.on("error", (error) => {
console.error("Socket error:", error);
console.log("Client disconnected");
server.listen(1337, "127.0.0.1");
console.log("Fee delegate service started ...");
服务器监听端口为 1337
。
当有 "数据 "传入时,它会用 "付费者私钥 "对 "数据 "进行签名,并将其发送到 Kaia 区块链。 它假定 data
是 sender_client.js
中的 senderTxHashRLP
。
4. 运行示例
准备两个终端,一个是 sender_client.js
终端,另一个是 feepayer_server.js
终端。
4.1 运行 feepayer_server.js
运行以下命令启动缴费服务器:
Fee delegate service started ...
服务器启动并监听 1337 端口。
4.2 运行 sender_client.js
让我们运行 sender_client.js
发送一笔委托收费交易。
to:'0x3a388d3fD71A0d9722c525E17007DdCcc41e1C47',
value: 10000000000000000n,
from: '0x7D3C7202582299470F2aD3DDCB8EF2F45407F871',
senderTxHashRLP0x09f88681ca85066720b30082cd14943a388d3fd71a0d9722c525e17007ddccc41e1c47872386f26fc10000947d3c7202582299470f2ad3ddcb8ef2f45407f871f847f8458207f6a0820d11029771f2fa368ce11da01f1c9e7f4de6d48915074d149e132692f9d63ea0131c62470a6799dfc5d7e3a7ac8d0a4f3b8fb8b59110ca5dabb26a9ee409f274
从服务器接收数据:这是费用委托,服务费支付方为 0x88311cD55B656D2502b50f62E83F8279c1641e70
它将用 "发送方 "私钥签署交易,并将签署后的交易发送到费用委托服务(即费用支付方的服务器)。 然后,它将收到缴费委托服务的响应,包括 "缴费人 "地址和 "发送哈希值"。 Tx hash "是提交给 Kaia 网络的交易的哈希值。
4.3 检查 feepayer_server.js
在服务器控制台,您将看到以下输出。 它可以打印来自 Kaia 的交易收据。
$ node feepayer_server.js
从客户端接收数据:0x09f88681ca85066720b30082cd14943a388d3fd71a0d9722c525e17007ddccc41e1c47872386f26fc10000947d3c7202582299470f2ad3ddcb8ef2f45407f871f847f8458207f6a0820d11029771f2fa368ce11da01f1c9e7f4de6d48915074d149e132692f9d63ea0131c62470a6799dfc5d7e3a7ac8d0a4f3b8fb8b59110ca5dabb26a9ee409f274
sentTx TransactionResponse {
to:'0x3a388d3fD71A0d9722c525E17007DdCcc41e1C47',
from: '0x7D3C7202582299470F2aD3DDCB8EF2F45407F871',
hash:0x7cb1e8d20b4db7d9db1abc094781e1af83a9391153aab8cc935510639a548222',
blockHash: '0x50d3d7e143579e17dbc17b761c8e04331c6d4d950fe7563ac9a79d42a649de0a',
logsBloom:'0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
cumulativeGasUsed:31000n,
4.4 对卡伊阿斯坎的看法
您还可以在 Kaiascan 上找到上述交易。
它显示交易为 "TxTypeFeeDelegatedValueTransfer","Fee payer "为 "0x88311cd55b656d2502b50f62e83f8279c1641e70 "或您输入的 "feepayerAddress",而 "From "是另一个地址,应为上例中的 "senderAddress"。
