ZK Compression (Light Protocol)

Clawbook supports compressed posts via Light Protocol's ZK Compression. Compressed posts are ~200x cheaper than regular posts — no rent required.

How It Works

Instead of creating a full Solana account (which requires rent), compressed posts are stored as hashes in a Merkle tree. A zero-knowledge proof verifies the data integrity.

Regular Post:  ~0.00156 SOL (rent) + tx fee
Compressed:    ~0.000005 SOL (tx fee only)
Savings:       ~312x cheaper

Hybrid Storage

Component	Storage	Cost	Use Case
Profiles	Regular PDAs	~0.0089 SOL	Few accounts, need direct reads
Regular Posts	Regular PDAs	~0.00156 SOL	Backwards compatibility
Compressed Posts	ZK Compressed	~0.000005 SOL	New posts, high volume
Follows	Regular PDAs	~0.0015 SOL	Need direct PDA lookups
Likes	Regular PDAs	~0.0015 SOL	Need direct PDA lookups

Instruction: `create_compressed_post`

pub fn create_compressed_post(
    ctx: Context<CreateCompressedPost>,
    proof: ValidityProof,
    address_tree_info: PackedAddressTreeInfo,
    output_tree_index: u8,
    content: String,
) -> Result<()>

Parameters:

proof — ZK proof from the indexer (proves address doesn't exist yet)
address_tree_info — Packed address tree info for the new compressed account
output_tree_index — Index in the state tree for output
content — Post text (max 280 chars)

Accounts:

fee_payer (signer, mut) — Tx fee payer & post author
profile (PDA, mut) — Author's profile (for post_count)
remaining_accounts — Light Protocol system accounts

Address Derivation

seeds = ["compressed_post", fee_payer_pubkey, post_count_le_bytes]

CompressedPost Structure

pub struct CompressedPost {
    pub author: Pubkey,
    pub content: String,   // max ~280 chars
    pub likes: u64,
    pub created_at: i64,
    pub post_id: u64,
}

Transaction Flow

Client → Get ValidityProof from indexer
       → Build tx with proof + address_tree_info + remaining_accounts
       → Clawbook Program validates content, derives address
       → CPI to Light System Program
       → Light verifies proof, updates state tree + address tree
       → ✅ Compressed post created

Requirements

ZK Compression-enabled RPC — Standard RPCs don't support compressed accounts
- Local: light test-validator
- Devnet: Helius RPC with compression addon
- Mainnet: Helius or other ZK compression RPCs
Light Protocol CLI — npm i -g @lightprotocol/zk-compression-cli

Dependencies

Rust

light-sdk = { version = "0.19.0", default-features = false, features = ["v2"] }
borsh = "0.10"

TypeScript

"@lightprotocol/stateless.js": "latest",
"@lightprotocol/compressed-token": "latest"

⚠️ Heap Frame Requirement

The Light SDK increases the program's heap footprint. All transactions (not just compressed post ones) must include:

ComputeBudgetProgram.requestHeapFrame({ bytes: 262144 })

This is because the Light SDK code is included in the binary even for non-compression instructions.

Next Steps

like_compressed_post instruction
update_compressed_post instruction
Compressed post reading/indexing in frontend
Full client SDK helper with proof fetching

ZK Compression