cNFT

cNFT (Compressed NFT)¶

cNFT (Compressed NFT) is a breakthrough technology developed by Metaplex that dramatically reduces NFT minting and storage costs through state compression, making large-scale NFT distribution possible.

Core Problem¶

Traditional NFTs Are Expensive - Each NFT requires an independent Token account - Rent-exempt balance: ~0.012 SOL - Minting 1 million NFTs: 12,000 SOL (millions of dollars) - Limits large-scale adoption

cNFT Solution¶

State Compression Uses Merkle trees to compress NFT data: - Only the tree root (32 bytes) is stored on-chain - Full data stored off-chain (Arweave/Shadow Drive) - Ownership verified through Merkle proofs

Cost Comparison - Traditional NFT: ~0.012 SOL each - cNFT: ~0.0001 SOL each - 100x reduction

How It Works¶

Merkle Tree Structure

              Root (on-chain)
             /              Hash    Hash
         /  \    /         H1  H2  H3  H4
       |   |   |   |
     NFT1 NFT2 NFT3 NFT4

Minting Flow 1. Add NFT data to Merkle tree 2. Update tree root on-chain 3. Store full data on Arweave

Verifying Ownership 1. User provides NFT data 2. Provides Merkle proof (path) 3. On-chain verification: Checks if computed root matches 4. Verification passes = Owns the NFT

Technical Implementation¶

Bubblegum Program Metaplex's cNFT program: - Manages Merkle trees - Verifies ownership - Handles transfers

Concurrent Merkle Trees Uses concurrent Merkle tree data structures: - Supports parallel updates - Avoids conflicts - Improves throughput

Tree Configuration

Tree depth: 14-30 (up to 2^30 NFTs)
Concurrency buffer: 8-2048

Use Cases¶

Large-Scale Airdrops - Community rewards - Event commemoratives - User retention

Game Assets - Game items - Character equipment - Consumables

Membership Systems - Membership cards - Point certificates - Access permissions

Utility NFTs - Tickets - Coupons - Certificates

Creating cNFTs¶

Using Bubblegum

import { createTree, mintV1 } from "@metaplex-foundation/mpl-bubblegum";

// Create Merkle tree
await createTree(umi, {
  merkleTree,
  maxDepth: 14,
  maxBufferSize: 64,
}).sendAndConfirm(umi);

// Mint cNFT
await mintV1(umi, {
  leafOwner: owner.publicKey,
  merkleTree: merkleTree.publicKey,
  metadata: {
    name: "My cNFT",
    uri: "https://arweave.net/...",
    sellerFeeBasisPoints: 500,
    collection: { key: collectionMint, verified: false },
    creators: [{ address: creator, verified: false, share: 100 }],
  },
}).sendAndConfirm(umi);

Reading cNFTs¶

Requires Indexing Service Since data is not fully on-chain, an indexer is needed: - Helius (best cNFT support) - SimpleHash - Shyft

API Query

// Helius API
const response = await fetch(
  `https://mainnet.helius-rpc.com/?api-key=${API_KEY}`,
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      jsonrpc: '2.0',
      id: 'my-id',
      method: 'getAssetsByOwner',
      params: { ownerAddress: walletAddress },
    }),
  }
);

Limitations and Trade-offs¶

Advantages - Extremely low cost - Strong scalability - Suitable for large-scale distribution

Disadvantages - Requires off-chain indexing - Queries more complex than traditional NFTs - Wallet support still maturing - Transfers require Merkle proofs

Ecosystem Support¶

Wallets - Phantom (supported) - Backpack (supported) - Solflare (supported)

Marketplaces - Tensor (native support) - Magic Eden (supported)

Tools - Helius (best indexer) - Metaplex SDK

Case Studies¶

Large-Scale Adoption - Mad Lads (10,000 cNFT collection) - Claynosaurz Pets (hundreds of thousands) - Various game projects

Cost Savings Minting 1 million cNFTs: - Traditional method: ~\(100,000 - cNFT: ~\)100 - 99.9% savings

Future Development¶

Broader Adoption As tools and support mature, cNFTs will become mainstream.

New Use Cases - On-chain identity - Social graphs - Large-scale loyalty programs

Merkle Tree: The data structure foundation of cNFTs
State Compression: Core technical principle
Bubblegum: The cNFT program
Helius: Leading cNFT indexer
Traditional NFT: Standard approach with individual accounts per NFT