Close mint

Configure the MintCloseAuthority extension to allow closing a mint account and reclaiming rent using Light Token.

A designated authority can close a mint account and reclaim its rent-exempt lamports after all tokens have been burned and the total supply reaches zero.

Set the compression_only flag when creating token accounts for this mint. Use transferInterface for transfers as usual.

Key Parameters

MintCloseAuthority is configured with one parameter:

Parameter	Description
closeAuthority	The public key authorized to close the mint account and reclaim its rent-exempt lamports.

Standard SPL mints cannot be closed once created, leaving rent-exempt lamports locked permanently. MintCloseAuthority adds a close authority that can reclaim those lamports after the total supply reaches zero.

Use MintCloseAuthority With Light Token

Agent skill

Install the agent skill:

npx skills add https://zkcompression.com

See the AI tools guide for dedicated skills.

Guide

Setup

npm install @lightprotocol/compressed-token@beta \
            @lightprotocol/stateless.js@beta \
            @solana/spl-token

Snippets below assume rpc, payer, mint, owner, recipient, and amount are defined. See the full examples for runnable setup.

import { createRpc } from "@lightprotocol/stateless.js";

const rpc = createRpc(RPC_ENDPOINT);

Create a Token-2022 Mint With Close Authority

Instruction

import {
    Keypair,
    SystemProgram,
    Transaction,
    sendAndConfirmTransaction,
} from "@solana/web3.js";
import { createRpc } from "@lightprotocol/stateless.js";
import { LightTokenProgram } from "@lightprotocol/compressed-token";
import {
    TOKEN_2022_PROGRAM_ID,
    ExtensionType,
    getMintLen,
    createInitializeMint2Instruction,
    createInitializeMintCloseAuthorityInstruction,
} from "@solana/spl-token";

const rpc = createRpc(RPC_ENDPOINT);

const mintKeypair = Keypair.generate();
const decimals = 9;

// Calculate space for mint + MintCloseAuthority extension
const mintLen = getMintLen([ExtensionType.MintCloseAuthority]);
const rentExemptBalance =
    await rpc.getMinimumBalanceForRentExemption(mintLen);

// Create account
const createAccountIx = SystemProgram.createAccount({
    fromPubkey: payer.publicKey,
    lamports: rentExemptBalance,
    newAccountPubkey: mintKeypair.publicKey,
    programId: TOKEN_2022_PROGRAM_ID,
    space: mintLen,
});

// Initialize MintCloseAuthority extension
const initMintCloseAuthorityIx = createInitializeMintCloseAuthorityInstruction(
    mintKeypair.publicKey,
    payer.publicKey, // close authority
    TOKEN_2022_PROGRAM_ID,
);

// Initialize mint
const initMintIx = createInitializeMint2Instruction(
    mintKeypair.publicKey,
    decimals,
    payer.publicKey, // mint authority
    null,            // freeze authority
    TOKEN_2022_PROGRAM_ID,
);

// Register interface PDA with Light Token
const createSplInterfaceIx = await LightTokenProgram.createSplInterface({
    feePayer: payer.publicKey,
    mint: mintKeypair.publicKey,
    tokenProgramId: TOKEN_2022_PROGRAM_ID,
});

const tx = new Transaction().add(
    createAccountIx,
    initMintCloseAuthorityIx,
    initMintIx,
    createSplInterfaceIx
);

const signature = await sendAndConfirmTransaction(rpc, tx, [
    payer,
    mintKeypair,
]);

Action

import "dotenv/config";
import {
    Keypair,
    SystemProgram,
    Transaction,
    sendAndConfirmTransaction,
} from "@solana/web3.js";
import { createRpc } from "@lightprotocol/stateless.js";
import { LightTokenProgram } from "@lightprotocol/compressed-token";
import {
    TOKEN_2022_PROGRAM_ID,
    ExtensionType,
    getMintLen,
    createInitializeMint2Instruction,
    createInitializeMintCloseAuthorityInstruction,
} from "@solana/spl-token";
import { homedir } from "os";
import { readFileSync } from "fs";

// devnet:
// const RPC_URL = `https://devnet.helius-rpc.com?api-key=${process.env.API_KEY!}`;
// const rpc = createRpc(RPC_URL);
// localnet:
const rpc = createRpc();

const payer = Keypair.fromSecretKey(
    new Uint8Array(
        JSON.parse(readFileSync(`${homedir()}/.config/solana/id.json`, "utf8"))
    )
);

(async function () {
    const mintKeypair = Keypair.generate();
    const decimals = 9;

    // 1. Calculate space including the MintCloseAuthority extension
    const mintLen = getMintLen([ExtensionType.MintCloseAuthority]);
    const rentExemptBalance = await rpc.getMinimumBalanceForRentExemption(
        mintLen
    );

    // 2. Create the mint account
    const createMintAccountIx = SystemProgram.createAccount({
        fromPubkey: payer.publicKey,
        lamports: rentExemptBalance,
        newAccountPubkey: mintKeypair.publicKey,
        programId: TOKEN_2022_PROGRAM_ID,
        space: mintLen,
    });

    // 3. Initialize the MintCloseAuthority extension
    const initMintCloseAuthorityIx =
        createInitializeMintCloseAuthorityInstruction(
            mintKeypair.publicKey,
            payer.publicKey, // close authority
            TOKEN_2022_PROGRAM_ID
        );

    // 4. Initialize the mint
    const initializeMintIx = createInitializeMint2Instruction(
        mintKeypair.publicKey,
        decimals,
        payer.publicKey, // mint authority
        null, // freeze authority
        TOKEN_2022_PROGRAM_ID
    );

    // 5. Register the SPL interface PDA with Light Token
    const createSplInterfaceIx = await LightTokenProgram.createSplInterface({
        feePayer: payer.publicKey,
        mint: mintKeypair.publicKey,
        tokenProgramId: TOKEN_2022_PROGRAM_ID,
    });

    const tx = new Transaction().add(
        createMintAccountIx,
        initMintCloseAuthorityIx,
        initializeMintIx,
        createSplInterfaceIx
    );

    const signature = await sendAndConfirmTransaction(rpc, tx, [
        payer,
        mintKeypair,
    ]);

    console.log("Mint:", mintKeypair.publicKey.toBase58());
    console.log("Tx:", signature);
})();

createMintInterface creates a basic Token 2022 mint with an interface PDA. To include the MintCloseAuthority extension, use the instruction approach shown in the other tab.

Create Interface PDA for Existing Mint

If you already have a Token-2022 mint with MintCloseAuthority, create an interface PDA with Light Token.

import { LightTokenProgram } from "@lightprotocol/compressed-token";
import { TOKEN_2022_PROGRAM_ID } from "@solana/spl-token";

const createSplInterfaceIx = await LightTokenProgram.createSplInterface({
    feePayer: payer.publicKey,
    mint: mintKeypair.publicKey,
    tokenProgramId: TOKEN_2022_PROGRAM_ID,
});

AI Prompt

Create a Token-2022 mint with MintCloseAuthority and register with Light Token

CopiedCopy promptOpen in Cursor

---
description: Create a Token-2022 mint with MintCloseAuthority and register with Light Token
allowed-tools: Bash, Read, Write, Edit, Glob, Grep, WebFetch, AskUserQuestion, Task, TaskCreate, TaskGet, TaskList, TaskUpdate, TaskOutput, mcp__deepwiki, mcp__zkcompression
---

## Create a Token-2022 mint with MintCloseAuthority and register with Light Token

Context:
- Guide: https://zkcompression.com/light-token/extensions/close-mint
- Skills and resources index: https://zkcompression.com/skill.md
- SPL to Light reference: https://zkcompression.com/api-reference/solana-to-light-comparison
- Packages: @lightprotocol/compressed-token, @lightprotocol/stateless.js, @solana/spl-token
- Restriction: compression_only accounts required

SPL equivalent: createInitializeMintCloseAuthorityInstruction() + createMint()
Light Token: createInitializeMintCloseAuthorityInstruction() + LightTokenProgram.createSplInterface()

### 1. Index project
- Grep `@solana/spl-token|Connection|Keypair|MintCloseAuthority|TOKEN_2022` across src/
- Glob `**/*.ts` for project structure
- Identify: RPC setup, existing mint logic, entry point for T22 mint with close authority
- Task subagent (Grep/Read/WebFetch) if project has multiple packages to scan in parallel

### 2. Read references
- WebFetch the guide above — follow the Instruction tab for the full flow
- WebFetch skill.md — check for a dedicated skill and resources matching this task
- TaskCreate one todo per phase below to track progress

### 3. Clarify intention
- AskUserQuestion: what is the goal? (new T22 mint with close authority, register existing T22 mint, migrate existing SPL code)
- AskUserQuestion: does the project already use Token-2022?
- Summarize findings and wait for user confirmation before implementing

### 4. Create plan
- Based on steps 1–3, draft an implementation plan: which files to modify, what code to add, dependency changes
- Verify existing connection/signer setup is compatible with the cookbook prerequisites
- Note: mint can only be closed when total supply is zero (all tokens burned)
- If anything is unclear or ambiguous, loop back to step 3 (AskUserQuestion)
- Present the plan to the user for approval before proceeding

### 5. Implement
- Add deps if missing: Bash `npm install @lightprotocol/compressed-token @lightprotocol/stateless.js @solana/spl-token`
- Create T22 mint: getMintLen([ExtensionType.MintCloseAuthority]) → SystemProgram.createAccount → createInitializeMintCloseAuthorityInstruction(closeAuthority) → createInitializeMint2Instruction
- Register with Light Token: LightTokenProgram.createSplInterface({ mint, tokenProgramId: TOKEN_2022_PROGRAM_ID })
- Transfer: createTransferInterfaceInstructions() from @lightprotocol/compressed-token/unified
- Write/Edit to create or modify files
- TaskUpdate to mark each step done

### 6. Verify
- Bash `tsc --noEmit`
- Bash run existing test suite if present
- Confirm close authority address is set correctly
- TaskUpdate to mark complete

### Tools
- mcp__zkcompression__SearchLightProtocol("<query>") for API details
- mcp__deepwiki__ask_question("Lightprotocol/light-protocol", "<q>") for architecture
- Task subagent with Grep/Read/WebFetch for parallel lookups
- TaskList to check remaining work

Related Guides

Transfer interface

Wrap and unwrap

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