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Solayer Chain uses 1% of Solana’s rent for account storage, making it 99% cheaper to create accounts. However, this difference requires developers to use the correct instructions to avoid overpaying rent when creating tokens and accounts.

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Why This Matters

Solana programs can fetch rent in two ways:
MethodBehaviorResult on Solayer Chain
Rent::get() syscallFetches rent from runtimeCorrect - uses Solayer Chain’s 1% rent
Rent::default()Uses hardcoded Solana valuesWrong - charges 100x too much
Instructions that rely on the Rent sysvar account internally use Rent::from_account_info(), which behaves like Rent::default() and returns Solana’s hardcoded rent values. This causes 100x overpayment on Solayer Chain.

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Token Program Instructions

The original Token Program includes both legacy instructions (which use the Rent sysvar) and newer variants (which use the Rent::get() syscall).

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Instructions to Avoid

InstructionIssue
InitializeMintRequires Rent sysvar, uses hardcoded rent
InitializeAccountRequires Rent sysvar, uses hardcoded rent
InitializeMultisigRequires Rent sysvar, uses hardcoded rent
InstructionBenefit
InitializeMint2Uses Rent::get() syscall, correct rent calculation
InitializeAccount2Uses Rent::get() syscall, correct rent calculation
InitializeAccount3Uses Rent::get() syscall, most efficient variant
InitializeMultisig2Uses Rent::get() syscall, correct rent calculation

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Token 2022 Instructions

Token 2022 (Token Extensions) follows the same pattern. Always use the “V2” or “V3” variants.

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Instructions to Avoid

InstructionIssue
InitializeMintRequires Rent sysvar
InitializeAccountRequires Rent sysvar
InitializeMultisigRequires Rent sysvar
InstructionBenefit
InitializeMint2Uses Rent::get() syscall
InitializeAccount2Uses Rent::get() syscall
InitializeAccount3Uses Rent::get() syscall, most efficient
InitializeMultisig2Uses Rent::get() syscall
Important for Token 2022: Account sizes vary based on enabled extensions. Always calculate sizes dynamically rather than hardcoding values.

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Code Examples

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Creating a Mint with InitializeMint2 (TypeScript)

import {
  Connection,
  Keypair,
  SystemProgram,
  Transaction,
} from "@solana/web3.js";
import {
  TOKEN_PROGRAM_ID,
  MINT_SIZE,
  createInitializeMint2Instruction,
} from "@solana/spl-token";

async function createMint(
  connection: Connection,
  payer: Keypair,
  mintAuthority: PublicKey,
  decimals: number
): Promise<PublicKey> {
  const mint = Keypair.generate();

  // Query rent from the chain - gets Solayer Chain's correct rent
  const lamports = await connection.getMinimumBalanceForRentExemption(MINT_SIZE);

  const transaction = new Transaction().add(
    SystemProgram.createAccount({
      fromPubkey: payer.publicKey,
      newAccountPubkey: mint.publicKey,
      space: MINT_SIZE,
      lamports, // Correct rent from chain
      programId: TOKEN_PROGRAM_ID,
    }),
    // Use InitializeMint2, NOT InitializeMint
    createInitializeMint2Instruction(
      mint.publicKey,
      decimals,
      mintAuthority,
      null, // freeze authority
      TOKEN_PROGRAM_ID
    )
  );

  await sendAndConfirmTransaction(connection, transaction, [payer, mint]);
  return mint.publicKey;
}

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Creating a Token Account with InitializeAccount3 (TypeScript)

import {
  Connection,
  Keypair,
  PublicKey,
  SystemProgram,
  Transaction,
} from "@solana/web3.js";
import {
  TOKEN_PROGRAM_ID,
  ACCOUNT_SIZE,
  createInitializeAccount3Instruction,
} from "@solana/spl-token";

async function createTokenAccount(
  connection: Connection,
  payer: Keypair,
  mint: PublicKey,
  owner: PublicKey
): Promise<PublicKey> {
  const account = Keypair.generate();

  // Query rent from the chain
  const lamports = await connection.getMinimumBalanceForRentExemption(ACCOUNT_SIZE);

  const transaction = new Transaction().add(
    SystemProgram.createAccount({
      fromPubkey: payer.publicKey,
      newAccountPubkey: account.publicKey,
      space: ACCOUNT_SIZE,
      lamports,
      programId: TOKEN_PROGRAM_ID,
    }),
    // Use InitializeAccount3 for best efficiency
    createInitializeAccount3Instruction(
      account.publicKey,
      mint,
      owner,
      TOKEN_PROGRAM_ID
    )
  );

  await sendAndConfirmTransaction(connection, transaction, [payer, account]);
  return account.publicKey;
}

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Token 2022 with Extensions (TypeScript)

import {
  Connection,
  Keypair,
  SystemProgram,
  Transaction,
} from "@solana/web3.js";
import {
  TOKEN_2022_PROGRAM_ID,
  ExtensionType,
  getMintLen,
  createInitializeMint2Instruction,
  createInitializeTransferFeeConfigInstruction,
} from "@solana/spl-token";

async function createMintWithTransferFee(
  connection: Connection,
  payer: Keypair,
  mintAuthority: PublicKey,
  decimals: number,
  feeBasisPoints: number,
  maxFee: bigint
): Promise<PublicKey> {
  const mint = Keypair.generate();

  // Calculate size dynamically based on extensions
  const extensions = [ExtensionType.TransferFeeConfig];
  const mintLen = getMintLen(extensions);

  // Query rent for the dynamic size
  const lamports = await connection.getMinimumBalanceForRentExemption(mintLen);

  const transaction = new Transaction().add(
    SystemProgram.createAccount({
      fromPubkey: payer.publicKey,
      newAccountPubkey: mint.publicKey,
      space: mintLen, // Dynamic size
      lamports,       // Correct rent from chain
      programId: TOKEN_2022_PROGRAM_ID,
    }),
    // Initialize extension BEFORE mint
    createInitializeTransferFeeConfigInstruction(
      mint.publicKey,
      mintAuthority,
      mintAuthority,
      feeBasisPoints,
      maxFee,
      TOKEN_2022_PROGRAM_ID
    ),
    // Use InitializeMint2
    createInitializeMint2Instruction(
      mint.publicKey,
      decimals,
      mintAuthority,
      null,
      TOKEN_2022_PROGRAM_ID
    )
  );

  await sendAndConfirmTransaction(connection, transaction, [payer, mint]);
  return mint.publicKey;
}

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Rust: Correct vs Incorrect Rent Usage

When writing custom Solana programs, always use Rent::get() instead of Rent::default(). 
use solana_program::rent::Rent;
use solana_program::sysvar::Sysvar;

// CORRECT: Uses syscall to fetch rent from runtime
fn get_rent_correct() -> Result<Rent, ProgramError> {
    Rent::get()
}

// INCORRECT: Returns hardcoded Solana rent values
fn get_rent_wrong() -> Rent {
    Rent::default() // DO NOT USE - ignores Solayer Chain's rent
}

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Best Practices Summary

  1. Always query rent from the chain 
    const lamports = await connection.getMinimumBalanceForRentExemption(size);
  2. Use “V2” or “V3” instruction variants - They use the Rent::get() syscall internally
  3. Calculate account sizes dynamically for Token 2022 - Use getMintLen() and getAccountLen() with your extensions
  4. In Rust programs, use Rent::get() - Never use Rent::default() which returns hardcoded values

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Quick Reference

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Safe Instructions (use Rent::get() syscall)

  • InitializeMint2
  • InitializeAccount2
  • InitializeAccount3
  • InitializeMultisig2

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Instructions to Avoid (use Rent sysvar)

  • InitializeMint
  • InitializeAccount
  • InitializeMultisig
By following these guidelines, your applications will correctly use Solayer Chain’s 99% cheaper rent and avoid overpaying for account creation.