备忘录转账扩展

MemoTranfer 扩展是一种 Token 账户扩展，它强制要求所有转入 token account 的转账都包含备忘录，从而增强交易跟踪和用户识别。

初始化 Token 账户

要在 MemoTransfer 扩展上初始化一个 Token 账户，我们需要使用 enableRequiredMemoTransfers() 函数。

以下是如何创建带有不可变所有者扩展的 token：

import {
    Keypair,
    SystemProgram,
    Transaction,
    sendAndConfirmTransaction,
} from '@solana/web3.js';
import {
    createInitializeAccountInstruction,
    createInitializeImmutableOwnerInstruction,
    getAccountLen,
    ExtensionType,
    TOKEN_2022_PROGRAM_ID,
} from '@solana/spl-token';
 
const tokenAccount = Keypair.generate();
 
// Calculate the size needed for a Token account with Transfer Fee extension
const accountLen = getAccountLen([ExtensionType.ImmutableOwner]);
 
// Calculate minimum lamports required for rent exemption
const lamports = await connection.getMinimumBalanceForRentExemption(accountLen);
 
// Create the account with the correct size and owner
const createAccountInstruction = SystemProgram.createAccount({
    fromPubkey: keypair.publicKey,
    newAccountPubkey: tokenAccount.publicKey,
    space: accountLen,
    lamports,
    programId: TOKEN_2022_PROGRAM_ID,
});
 
// Initialize the Memo Transfer extension
const enableMemoTransferInstruction = createEnableRequiredMemoTransfersInstruction(
    destinationTokenAccount.publicKey,
    destinationKeypair.publicKey,
    undefined,
    TOKEN_2022_PROGRAM_ID,
);
 
// Initialize the Token account itself
const initializeAccountInstruction = createInitializeAccountInstruction(
    tokenAccount.publicKey,
    mint.publicKey,
    keypair.publicKey,
    TOKEN_2022_PROGRAM_ID,
);
 
const transaction = new Transaction().add(
    createAccountInstruction,
    initializeAccountInstruction,
    enableMemoTransferInstruction,
);
 
const signature = await sendAndConfirmTransaction(connection, transaction, [keypair, tokenAccount], {skipPreflight: false});
 
console.log(`Token accounts created! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`);

带备忘录的 Token 转账

要在 Solana 上使用 Memo 程序，我们有两种可行路径。

构建我们自己的“原始”备忘录指令，如下所示：

const message = "Hello, Solana";
 
new TransactionInstruction({
    keys: [{ pubkey: keypair.publicKey, isSigner: true, isWritable: true }],
    data: Buffer.from(message, "utf-8"), // Memo message. In this case it is "Hello, Solana"
    programId: new PublicKey("MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr"), // Memo program that validates keys and memo message
}),
 
或者，我们可以在下载该软件包后，使用 Memo 程序的软件开发工具包，如下所示：

npm i @solana/spl-memo


在我们的示例中，我们将使用后者，代码如下：

ts const memoInstruction = createMemoInstruction( "Hello, world!", [keypair.publicKey], );

const transferInstruction = createTransferCheckedInstruction( tokenAccount, mint.publicKey, destinationTokenAccount.publicKey, keypair.publicKey, BigInt(100e6), 6, undefined, TOKEN_2022_PROGRAM_ID, );

const transferTransaction = new Transaction().add( memoInstruction, transferInstruction, );

const transferSignature = await sendAndConfirmTransaction(connection, transferTransaction, [keypair]);

console.log(Tokens transferred with memo! Check out your TX here: https://explorer.solana.com/tx/${transferSignature}?cluster=devnet);


<ArticleSection name="Disabling and Enabling the Memo" id="disabling-and-enabling-the-memo" level="h2" />

如果我们不想强制要求转账必须附带备注，可以使用 memo_transfer_disable 函数来实现，具体如下：

ts const disableRequiredMemoTransfersInstruction = createDisableRequiredMemoTransfersInstruction( destinationTokenAccount, destinationKeypair.publicKey, undefined, TOKEN_2022_PROGRAM_ID, );

const transferInstruction = createTransferCheckedInstruction( tokenAccount, mint.publicKey, destinationTokenAccount, keypair.publicKey, BigInt(100e6), 6, undefined, TOKEN_2022_PROGRAM_ID, );

const transaction = new Transaction().add( disableRequiredMemoTransfersInstruction, transferInstruction, );

const signature = await sendAndConfirmTransaction(connection, transaction, [keypair, destinationKeypair]);

console.log(Tokens transferred and account state changed! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet);


如需恢复强制备注要求，只需调用 enableRequiredMemoTransfers() 函数，示例如下：

ts const enableRequiredMemoTransfersInstruction = createEnableRequiredMemoTransfersInstruction( destinationTokenAccount, destinationKeypair.publicKey, undefined, TOKEN_2022_PROGRAM_ID, );