ZK Compression on Solana

ZK Compression enables rent-free tokens and PDAs on Solana by storing state on the ledger instead of in accounts, using zero-knowledge proofs to validate state transitions. Built by Light Protocol and indexed by Helius Photon.

When to Use ZK Compression

Use ZK Compression when:

• Creating millions of token accounts (5000x cheaper than regular accounts)
• Minting to many recipients (airdrops, loyalty programs, gaming assets)
• Building apps with many user accounts that are infrequently updated
• Reducing rent costs for PDAs with low update frequency

Use regular accounts when:

• Account is updated frequently (>1000 lifetime writes)
• Account stores large data accessed in on-chain transactions
• Compute budget is critical (compression adds ~100k CU overhead)

Quick Start

Installation

# TypeScript client
npm install @lightprotocol/stateless.js @lightprotocol/compressed-token

# Rust SDK for programs
cargo add light-sdk

# CLI for development
npm install -g @lightprotocol/zk-compression-cli

Local Development

# Start local validator with compression support
light test-validator

# Initialize a new Anchor project with compression
light init my-program

Mint Compressed Tokens (TypeScript)

import { createRpc } from '@lightprotocol/stateless.js';
import { createMint, mintTo, transfer } from '@lightprotocol/compressed-token';

const rpc = createRpc(); // or createRpc('https://mainnet.helius-rpc.com?api-key=YOUR_KEY')

// Create mint with token pool for compression
const { mint } = await createMint(rpc, payer, payer.publicKey, 9);

// Mint compressed tokens (creates compressed token accounts)
await mintTo(rpc, payer, mint, recipient, payer, 1_000_000_000);

// Transfer compressed tokens
await transfer(rpc, payer, mint, 500_000_000, owner, recipient);

// Query compressed token accounts
const accounts = await rpc.getCompressedTokenAccountsByOwner(owner, { mint });

Build Program with Compressed PDAs (Anchor)

use anchor_lang::prelude::*;
use light_sdk::{
    account::LightAccount,
    address::v1::derive_address,
    cpi::{v1::CpiAccounts, CpiSigner},
    derive_light_cpi_signer,
    instruction::{account_meta::CompressedAccountMeta, PackedAddressTreeInfo, ValidityProof},
    LightDiscriminator, LightHasher,
};

declare_id!("YourProgramID");

pub const LIGHT_CPI_SIGNER: CpiSigner = derive_light_cpi_signer!("YourProgramID");

#[program]
pub mod my_program {
    use super::*;
    use light_sdk::cpi::{v1::LightSystemProgramCpi, InvokeLightSystemProgram};

    pub fn create_account<'info>(
        ctx: Context<'_, '_, '_, 'info, MyAccounts<'info>>,
        proof: ValidityProof,
        address_tree_info: PackedAddressTreeInfo,
        output_state_tree_index: u8,
    ) -> Result<()> {
        let light_cpi_accounts = CpiAccounts::new(
            ctx.accounts.signer.as_ref(),
            ctx.remaining_accounts,
            crate::LIGHT_CPI_SIGNER,
        );

        let (address, address_seed) = derive_address(
            &[b"my_account", ctx.accounts.signer.key().as_ref()],
            &address_tree_info.get_tree_pubkey(&light_cpi_accounts)?,
            &crate::ID,
        );

        let new_address_params = address_tree_info.into_new_address_params_packed(address_seed);

        // Create new compressed account
        let mut account = LightAccount::<MyAccount>::new_init(
            &crate::ID,
            Some(address),
            output_state_tree_index,
        );
        account.owner = ctx.accounts.signer.key();
        account.data = 0;

        LightSystemProgramCpi::new_cpi(LIGHT_CPI_SIGNER, proof)
            .with_light_account(account)?
            .with_new_addresses(&[new_address_params])
            .invoke(light_cpi_accounts)?;

        Ok(())
    }

    pub fn update_account<'info>(
        ctx: Context<'_, '_, '_, 'info, MyAccounts<'info>>,
        proof: ValidityProof,
        current_data: u64,
        account_meta: CompressedAccountMeta,
    ) -> Result<()> {
        // Modify existing compressed account
        let mut account = LightAccount::<MyAccount>::new_mut(
            &crate::ID,
            &account_meta,
            MyAccount {
                owner: ctx.accounts.signer.key(),
                data: current_data,
            },
        )?;

        account.data = account.data.checked_add(1).unwrap();

        let light_cpi_accounts = CpiAccounts::new(
            ctx.accounts.signer.as_ref(),
            ctx.remaining_accounts,
            crate::LIGHT_CPI_SIGNER,
        );

        LightSystemProgramCpi::new_cpi(LIGHT_CPI_SIGNER, proof)
            .with_light_account(account)?
            .invoke(light_cpi_accounts)?;

        Ok(())
    }
}

#[derive(Accounts)]
pub struct MyAccounts<'info> {
    #[account(mut)]
    pub signer: Signer<'info>,
}

#[event]
#[derive(Clone, Debug, Default, LightDiscriminator, LightHasher)]
pub struct MyAccount {
    #[hash]
    pub owner: Pubkey,
    pub data: u64,
}

Core Concepts

Compressed Account Model

Compressed accounts are similar to regular Solana accounts but stored differently:

Aspect	Regular Account	Compressed Account
Storage	AccountsDB (disk)	Ledger (call data)
Rent	Required (~0.002 SOL per 100 bytes)	None
Identification	Pubkey	Hash (changes on write) or Address
State validation	Runtime checks	ZK validity proofs

Key differences:

• Hash changes on every write (accounts identified by content hash)
• Optional persistent address for PDAs (similar to regular PDAs)
• State stored in Merkle trees with only roots on-chain

State Trees

Compressed accounts are stored in concurrent Merkle trees using Poseidon hashing:

• Only the tree root is stored on-chain
• Leaves contain compressed account hashes
• Validity proofs prove account inclusion in tree

Validity Proofs

ZK proofs (Groth16) validate state transitions:

• Prove existence of N accounts in M state trees
• Constant 128-byte proof size regardless of accounts
• ~100k CU for proof verification

Transaction Lifecycle

1. Build: Client fetches compressed accounts and validity proofs via RPC
2. Submit: Transaction includes account data + proof in payload
3. Validate: Light System Program verifies proof and account integrity
4. Update: New state appended to tree, old state nullified
5. Index: Photon RPC nodes index new state from ledger

LightAccount Operations

// Create new account (no input state, only output)
let account = LightAccount::<T>::new_init(&program_id, Some(address), tree_index);

// Modify existing account (input + output state)
let mut account = LightAccount::<T>::new_mut(&program_id, &account_meta, current_state)?;
account.field = new_value;

// Close account (input state, no output)
let account = LightAccount::<T>::new_close(&program_id, &account_meta, current_state)?;

Helius SDK Integration

Query compressed state via Helius RPC:

import { Helius } from 'helius-sdk';

const helius = new Helius('YOUR_API_KEY');

// Get compressed account by hash or address
const account = await helius.zk.getCompressedAccount({ address });

// Get all compressed accounts for owner
const accounts = await helius.zk.getCompressedAccountsByOwner(owner);

// Get compressed token accounts
const tokenAccounts = await helius.zk.getCompressedTokenAccountsByOwner(owner, { mint });

// Get validity proof for accounts
const proof = await helius.zk.getValidityProof({ hashes: [hash1, hash2] });

// Get compression signatures for account
const signatures = await helius.zk.getCompressionSignaturesForAccount(hash);

RPC Methods

ZK Compression RPC API (via Helius or self-hosted Photon):

Method	Description
getCompressedAccount	Get account by hash or address
getCompressedAccountsByOwner	Get all accounts owned by pubkey
getCompressedTokenAccountsByOwner	Get token accounts for owner
getCompressedTokenBalancesByOwner	Get token balances summary
getValidityProof	Get ZK proof for account inclusion
getMultipleCompressedAccounts	Batch fetch accounts
getCompressionSignaturesForAccount	Get transaction history

Infrastructure

Node Types

Node	Purpose	Run By
Photon RPC	Index compressed state, serve queries	Helius (canonical), self-host
Prover	Generate validity proofs	Bundled with Photon or standalone
Forester	Maintain state trees, empty nullifier queues	Light Protocol, community

Running Photon Locally

# Install
cargo install photon-indexer

# Run against devnet
photon --rpc-url=https://api.devnet.solana.com

# With Postgres for production
photon --db-url=postgres://postgres@localhost/postgres --rpc-url=<RPC_URL>

# Load from snapshot for faster bootstrap
photon-snapshot-loader --snapshot-dir=~/snapshot --snapshot-server-url=https://photon-devnet-snapshot.helius-rpc.com

Trade-offs

Consideration	Impact
Larger transactions	+128 bytes for proof + account data in payload
Higher CU usage	~100k CU proof verification + ~6k CU per account
Per-write cost	Each write nullifies old state, appends new
Indexer dependency	Requires Photon RPC (or self-host) for queries

Break-even analysis: Compressed account becomes more expensive than regular account after ~1000 writes.

Reference Documentation

• compressed-accounts.md - Detailed account model, hashing, addresses
• compressed-tokens.md - Token operations, pools, batch operations
• compressed-pdas.md - Building programs with compressed PDAs
• client-integration.md - TypeScript/Rust client setup, RPC methods

Resources

• ZK Compression Docs
• Light Protocol GitHub
• Helius SDK
• Photon Indexer
• Program Examples
• Helius ZK Blog