Mint Close Authority 扩展

Name: 使用 Web3.js 的 Token2022
Availability: InStock

MintCloseAuthority 扩展是一个 Mint 扩展，允许权限方关闭并从当前供应量为 0 的 Mint 账户中取回租金。

此扩展对于清理未使用的铸币账户并回收用于支付账户租金豁免的 SOL 非常有用。只有在没有代币流通时，铸币账户才能被关闭。

初始化铸币账户

要在 Mint 账户上初始化 MintCloseAuthority 扩展，我们需要使用 initializeMintCloseAuthority() 函数。

以下是如何创建带有 Mint Close 扩展的铸币账户：

import { Keypair, SystemProgram, Transaction, sendAndConfirmTransaction } from "@solana/web3.js";
import {
  createInitializeMintInstruction,
  createInitializeMintCloseAuthorityInstruction,
  getMintLen,
  ExtensionType,
  TOKEN_2022_PROGRAM_ID,
} from "@solana/spl-token";

const mint = Keypair.generate();

// Calculate the size needed for a Mint account with Transfer Fee extension
const mintLen = getMintLen([ExtensionType.MintCloseAuthority]);

// Calculate minimum lamports required for rent exemption
const lamports = await connection.getMinimumBalanceForRentExemption(mintLen);

// Create the account with the correct size and owner
const createAccountInstruction = SystemProgram.createAccount({
  fromPubkey: keypair.publicKey,
  newAccountPubkey: mint.publicKey,
  space: mintLen,
  lamports,
  programId: TOKEN_2022_PROGRAM_ID,
});

// Initialize the Mint Close Authority extension
const initializeMintCloseAuthority = createInitializeMintCloseAuthorityInstruction(
  mint.publicKey,
  keypair.publicKey,
  TOKEN_2022_PROGRAM_ID,
);

// Initialize the mint itself
const initializeMintInstruction = createInitializeMintInstruction(
  mint.publicKey,
  6,
  keypair.publicKey,
  null,
  TOKEN_2022_PROGRAM_ID,
);

// Combine all instructions in the correct order
const transaction = new Transaction().add(
  createAccountInstruction,
  initializeMintCloseAuthority,
  initializeMintInstruction,
);

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

console.log(
  `Mint created! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`,
);

Expand

[39 more lines]

关闭铸币账户

如果 Mint 账户的供应量为零，CloseMint Authority 可以通过使用 closeAccount 指令来回收该账户的租金，如下所示：

const closeMintInstruction = createCloseAccountInstruction(
  mint.publicKey,
  keypair.publicKey,
  keypair.publicKey,
  [],
  TOKEN_2022_PROGRAM_ID,
);

const transaction = new Transaction().add(closeMintInstruction);

const signature = await sendAndConfirmTransaction(connection, transaction, [keypair], {
  skipPreflight: false,
});

console.log(
  `Mint closed! Check out your TX here: https://explorer.solana.com/tx/${signature}?cluster=devnet`,
);

Expand

[2 more lines]