手续费抽象

每笔 Solana 交易都需要使用 SOL 支付网络手续费。但用户在使用你的支付应用时，通常希望用稳定币进行交易，而不想管理第二种代币余额。手续费抽象通过让其他人代为支付手续费，消除了这一障碍。

本指南涵盖两个层面：

手续费赞助的工作原理 — Solana 的底层机制
使用 Kora 实现大规模手续费抽象 — 可用于生产环境的手续费抽象服务

手续费赞助的工作原理

Solana 交易有一个指定的手续费支付者——即负责支付网络手续费的账户。默认情况下，这个账户是第一个签名者。但你也可以指定其他账户作为手续费支付者，从而让第三方（即“赞助者”）代表发送方支付手续费。

发送方和赞助者都必须对交易进行签名：

发送方 签名以授权其代币的转账
赞助者 签名以授权支付网络手续费

参见 Solana 支付原理了解核心支付概念。

以下步骤展示了核心流程。完整可运行代码请参见演示。

创建赞助者账户

为将要支付交易手续费的赞助者生成一个独立的 keypair。赞助者需要持有用于支付手续费的 SOL，但无需持有被转账的代币。

Sponsor Transaction Fee

const sponsor = await generateKeyPairSigner();

创建转账指令

创建以发送方为授权人的代币转账指令。发送方拥有代币，必须对转账进行签名。

Sponsor Transaction Fee

const sponsor = await generateKeyPairSigner();

const transferInstruction = getTransferCheckedInstruction({
  source: senderAta,
  mint: mint.address,
  destination: recipientAta,
  authority: sender, // Sender signs for the transfer
  amount: 250_000n, // adjusted for the mint's decimals
  decimals: 6
});

由赞助方作为手续费支付者进行发送

通过 payer(sponsor) 将赞助商设置为手续费支付方来创建客户端，然后调用 client.sendTransaction。赞助商签名以支付网络费用，而发送方签名以授权转账——sendTransaction 会自动收集所有被引用的签名者。

Sponsor Transaction Fee

const sponsor = await generateKeyPairSigner();

const transferInstruction = getTransferCheckedInstruction({
  source: senderAta,
  mint: mint.address,
  destination: recipientAta,
  authority: sender,
  amount: 250_000n,
  decimals: 6
});

const client = createClient()
  .use(payer(sponsor)) // Sponsor pays the transaction fees
  .use(solanaLocalRpc());

const { context } = await client.sendTransaction([transferInstruction]);

创建赞助者账户

为将要支付交易手续费的赞助者生成一个独立的 keypair。赞助者需要持有用于支付手续费的 SOL，但无需持有被转账的代币。

创建转账指令

创建以发送方为授权人的代币转账指令。发送方拥有代币，必须对转账进行签名。

由赞助方作为手续费支付者进行发送

Sponsor Transaction Fee

const sponsor = await generateKeyPairSigner();

演示

Demo



// Generate keypairs for sender, recipient, and sponsor (fee payer)
const sender = await generateKeyPairSigner();
const recipient = await generateKeyPairSigner();
const sponsor = await generateKeyPairSigner();

console.log("Sender Address:", sender.address);
console.log("Recipient Address:", recipient.address);
console.log("Sponsor Address (Fee Payer):", sponsor.address);

// Demo Setup: Create client, mint account, token accounts, and fund with initial tokens
const { client, mint } = await demoSetup(sender, recipient, sponsor);

console.log("\nMint Address:", mint.address);

// Derive the Associated Token Accounts addresses (ATAs) for sender and recipient
const [senderAta] = await findAssociatedTokenPda({
  mint: mint.address,
  owner: sender.address,
  tokenProgram: TOKEN_2022_PROGRAM_ADDRESS
});

const [recipientAta] = await findAssociatedTokenPda({
  mint: mint.address,
  owner: recipient.address,
  tokenProgram: TOKEN_2022_PROGRAM_ADDRESS
});

console.log("Sender Token Account:", senderAta.toString());
console.log("Recipient Token Account:", recipientAta.toString());

// =============================================================================
// Sponsored Token Payment Demo
// =============================================================================

// Create instruction to transfer tokens from sender to recipient
// Transferring 250,000 base units = 0.25 tokens (with 6 decimals)
const transferInstruction = getTransferCheckedInstruction({
  source: senderAta,
  mint: mint.address,
  destination: recipientAta,
  authority: sender, // Sender signs to authorize the transfer
  amount: 250_000n, // 0.25 tokens
  decimals: 6
});

// Send transaction with sponsor as fee payer using @solana/kit
// The sponsor (client.payer) pays fees; the sender signs for the transfer
const { context } = await client.sendTransaction([transferInstruction]);
const signature = context.signature;

console.log("\n=== Sponsored Token Payment Complete ===");
console.log("Transaction Signature:", signature.toString());

// Fetch final token account balances from the RPC
const senderBalance = await client.rpc.getTokenAccountBalance(senderAta).send();
const recipientBalance = await client.rpc
  .getTokenAccountBalance(recipientAta)
  .send();

console.log("\nSender Token Account Balance:", senderBalance.value.uiAmount);
console.log(
  "Recipient Token Account Balance:",
  recipientBalance.value.uiAmount
);

// Fetch transaction details
const transaction = await client.rpc
  .getTransaction(signature, {
    encoding: "jsonParsed",
    maxSupportedTransactionVersion: 0
  })
  .send();

const feePayer = transaction?.transaction.message.accountKeys?.[0];
console.log("\nNote: The first account in accountKeys is always the fee payer");
console.log("Fee Payer Address:", feePayer);

// =============================================================================
// Demo Setup Helper Function
// =============================================================================

Console

Click to execute the code.

Demo



// Generate keypairs for sender, recipient, and sponsor (fee payer)
const sender = await generateKeyPairSigner();
const recipient = await generateKeyPairSigner();
const sponsor = await generateKeyPairSigner();

console.log("Sender Address:", sender.address);
console.log("Recipient Address:", recipient.address);
console.log("Sponsor Address (Fee Payer):", sponsor.address);

// Demo Setup: Create client, mint account, token accounts, and fund with initial tokens
const { client, mint } = await demoSetup(sender, recipient, sponsor);

console.log("\nMint Address:", mint.address);

// Derive the Associated Token Accounts addresses (ATAs) for sender and recipient
const [senderAta] = await findAssociatedTokenPda({
  mint: mint.address,
  owner: sender.address,
  tokenProgram: TOKEN_2022_PROGRAM_ADDRESS
});

const [recipientAta] = await findAssociatedTokenPda({
  mint: mint.address,
  owner: recipient.address,
  tokenProgram: TOKEN_2022_PROGRAM_ADDRESS
});

console.log("Sender Token Account:", senderAta.toString());
console.log("Recipient Token Account:", recipientAta.toString());

// =============================================================================
// Sponsored Token Payment Demo
// =============================================================================

// Create instruction to transfer tokens from sender to recipient
// Transferring 250,000 base units = 0.25 tokens (with 6 decimals)
const transferInstruction = getTransferCheckedInstruction({
  source: senderAta,
  mint: mint.address,
  destination: recipientAta,
  authority: sender, // Sender signs to authorize the transfer
  amount: 250_000n, // 0.25 tokens
  decimals: 6
});

// Send transaction with sponsor as fee payer using @solana/kit
// The sponsor (client.payer) pays fees; the sender signs for the transfer
const { context } = await client.sendTransaction([transferInstruction]);
const signature = context.signature;

console.log("\n=== Sponsored Token Payment Complete ===");
console.log("Transaction Signature:", signature.toString());

// Fetch final token account balances from the RPC
const senderBalance = await client.rpc.getTokenAccountBalance(senderAta).send();
const recipientBalance = await client.rpc
  .getTokenAccountBalance(recipientAta)
  .send();

console.log("\nSender Token Account Balance:", senderBalance.value.uiAmount);
console.log(
  "Recipient Token Account Balance:",
  recipientBalance.value.uiAmount
);

// Fetch transaction details
const transaction = await client.rpc
  .getTransaction(signature, {
    encoding: "jsonParsed",
    maxSupportedTransactionVersion: 0
  })
  .send();

const feePayer = transaction?.transaction.message.accountKeys?.[0];
console.log("\nNote: The first account in accountKeys is always the fee payer");
console.log("Fee Payer Address:", feePayer);

// =============================================================================
// Demo Setup Helper Function
// =============================================================================

Console

Click to execute the code.

当你为终端用户创建 token account 时，他们可以关闭该账户并取回用于 rent 的 SOL。建议向用户收取账户创建费用（如以稳定币结算），或将此成本计入你的产品经济模型中。

使用 Kora 实现大规模手续费抽象

fee payer 原语非常强大，但要构建生产级的免 gas 系统，还需要更多功能：管理赞助钱包、处理 token 兑换（让用户可以用 USDC "支付" 手续费）、限流和安全控制。

Kora 处理这种复杂性。它是一个 JSON-RPC 服务器，提供费用抽象功能，使用户永远不需要 SOL。您可以完全赞助费用或接受以任何代币支付费用。

只需一条命令即可部署 Kora：

cargo install kora-cli
kora --config path/to/kora.toml rpc start --signers-config path/to/signers.toml

然后将 Kit 客户端指向您的 Kora 服务器，并使用与上述相同的 API 发送交易：

pnpm add @solana/kora

import { address } from "@solana/kit";
import { createKitKoraClient } from "@solana/kora";

// A Kora-backed Kit client: Kora is the fee payer, and users pay
// fees in the SPL token of your choice instead of SOL
const kora = await createKitKoraClient({
  endpoint: "https://your-kora-instance",
  rpcUrl: "https://api.mainnet-beta.solana.com",
  feeToken: address("EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v"), // USDC
  feePayerWallet: sender // Signs to authorize the token fee payment
});

// Same instruction, same call—Kora sponsors the network fee
const { context } = await kora.sendTransaction([transferInstruction]);
console.log("Signature:", context.signature);

手续费抽象

手续费赞助的工作原理

创建赞助者账户

创建转账指令

由赞助方作为手续费支付者进行发送

创建赞助者账户

创建转账指令

由赞助方作为手续费支付者进行发送

演示

使用 Kora 实现大规模手续费抽象

Kora 资源

Kora 快速入门

完整交易演示

API 参考

节点运营商指南

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