Core Concepts to the Light Token Program (Beta)

The Light Token Program is a high performance token program that reduces the cost of account creations by 200x, while being more CU efficient than SPL on hot paths.

	Account Type	Key Features
Mint Accounts	Solana Account	Represents a unique mint and optionally can store token-metadata. Functionally equivalent to SPL mints. Sponsored rent exemption via custom rent-config
Token Accounts	Solana account	Stores token balances of mints (SPL, Token-2022, or Light) Sponsored rent exemption via custom rent-config

Rent Config by Light Token Program

1. The rent-exemption for light account creation is sponsored by the Light Token Program.
2. Transaction payer’s pay rent per rent-epoch (388 lamports for 1.5h)
   to keep accounts “active”.
3. “Inactive” accounts (rent below one epoch) get automatically compressed.
4. The account’s state is cryptographically preserved and will be loaded into hot account state in-flight, when the account is used again.
   

The hot state fee is paid for by the transaction payer when writing to the respective account.

Mint Accounts

Light mints are on-chain accounts like SPL mints, but with rent-exemption paid for by the Token program, instead of the user.

Light-mints uniquely represent a token on Solana and store its global metadata, similar to SPL mint accounts with few core differences:

1. Tokens created from light-mints are light-tokens.
2. Token metadata (name, symbol, URI) is stored as an extension in the struct.

	Light-Token	SPL-Token
Mint Account	0.00001 SOL	0.0015 SOL

Diagram

Source Code

pub struct CompressedMint {
    pub base: BaseMint,
    pub metadata: CompressedMintMetadata,
    /// Reserved bytes for T22 layout compatibility (padding to reach byte 165)
    pub reserved: [u8; 49],
    /// Account type discriminator at byte 165 (1 = Mint, 2 = Account)
    pub account_type: u8,
    /// Compression info embedded directly in the mint
    pub compression: CompressionInfo,
    pub extensions: Option<Vec<ExtensionStruct>>,
}

Find the source code of light-mints here.

The metadata field is used by the Compressed Token Program to store the internal state of a light-mint.

The BaseMint field replicates the field layout and serialization format of SPL Mint accounts. The struct is serialized with Borsh to match the on-chain format of SPL tokens and mints.

Here is how light-mints and SPL mints compare:

Basemint vs SPL mint

Field	Light-Mint	SPL Mint
mint_authority	✓	✓
supply	✓	✓
decimals	✓	✓
is_initialized	✓	✓
freeze_authority	✓	✓
Light-Mint Data	✓	-
Extensions	✓	via Token-2022

BaseMint Struct

pub struct BaseMint {
    /// Optional authority used to mint new tokens. The mint authority may only
    /// be provided during mint creation. If no mint authority is present
    /// then the mint has a fixed supply and no further tokens may be
    /// minted.
    pub mint_authority: Option<Pubkey>,
    /// Total supply of tokens.
    pub supply: u64,
    /// Number of base 10 digits to the right of the decimal place.
    pub decimals: u8,
    /// Is initialized - for SPL compatibility
    pub is_initialized: bool,
    /// Optional authority to freeze token accounts.
    pub freeze_authority: Option<Pubkey>,
}

Token Account

Light token accounts are on-chain accounts like SPL token accounts, but with rent-exemption paid for by the Token program, instead of the user.

A light-token account holds token balances like SPL Token accounts:

• A wallet needs a light-token account for each light-mint, SPL mint, or Token 2022 mint it wants to hold, with the wallet address set as the light-token account owner.
• Each wallet can own multiple light-token accounts for the same light-mint.
• A light-token account can only have one owner and hold units of one light-mint.

	Light-Token	SPL-Token
Token Account	~0.00001 SOL	~0.002 SOL

Additionally Light Token is more compute-efficient than SPL on hot paths:

	Light-Token	SPL-Token
ATA Creation	4,348	14,194
Transfer	312	4,645
Transfer (rent-free)	1,885	4,645

Diagram

Source Code

/// Ctoken account structure (with extensions).
pub struct CToken {
    pub mint: Pubkey,
    pub owner: Pubkey,
    pub amount: u64,
    pub delegate: Option<Pubkey>, // instruction not implemented yet
    pub state: u8,
    pub is_native: Option<u64>,
    pub delegated_amount: u64, // instruction not implemented yet
    pub close_authority: Option<Pubkey>,
    pub extensions: Option<Vec<ExtensionStruct>>, // Optional extensions e.g. compressible
}

Find the source code of light-tokens here.

Light token accounts replicate the field layout and serialization format of SPL Token accounts. The struct is serialized with Borsh to match the on-chain format of SPL tokens.

Here is how light-tokens and SPL tokens compare:

Field	Light Token	SPL Token Account
mint	✓	✓
owner	✓	✓
amount	✓	✓
delegate	unimplemented	✓
state	✓	✓
is_native	✓	✓
delegated_amount	unimplemented	✓
close_authority	✓	✓
extensions	✓	via Token-2022

Associated Light Token Account

Associated light-token accounts (light-ATAs) follow the same pattern as associated token accounts (ATA):

• Each wallet needs its own light-token account to hold tokens from the same light-mint.
• The address for light-ATAs is deterministically derived with the owner’s address, light token program ID, and mint address.

let seeds = [
    owner.as_ref(),          // Wallet address (32 bytes)
    program_id.as_ref(),     // Compressed Token Program ID (32 bytes)
    mint.as_ref(),           // light-mint address (32 bytes)
    bump.as_ref(),           // Bump seed (1 byte)
];

Find the source code to associated light-token accounts here.

Compressed Token Account

Under the hood, compressed token accounts store token balance, owner, and other information of inactive light-tokens.

1. Light token accounts are automatically compressed/decompressed when active/inactive.
2. Any light-token or SPL token can be compressed/decompressed at will.

You can still use compressed tokens for token distribution. Learn more about this here.

Diagram

Source Code

pub struct TokenData {
    pub mint: Pubkey,
    pub owner: Pubkey,
    pub amount: u64,
    pub delegate: Option<Pubkey>,
    pub state: u8,
    /// Placeholder for TokenExtension tlv data (unimplemented)
    pub tlv: Option<Vec<u8>>,
}

Next Steps

Create Light Token Accounts