🌳

Gasless cNFT Minting (Metaplex Bubblegum)

Mint compressed NFTs using Metaplex Bubblegum

🤝 LazorKit x Bubblegum

Regular NFT

~0.02 SOL per mint
4 accounts created
6 instructions
User pays rent

Compressed NFT

0 accounts created
1 instruction
Gas sponsored by paymaster
Truly gasless!

* Tree creation is a one-time cost paid by the platform

Making Bubblegum Work with LazorKit

1.Build Bubblegum Mint Instruction

Use Umi with Bubblegum to mint to a pre-created merkle tree:

// From lib/nft-utils.ts
const umi = createUmi(RPC_URL).use(mplBubblegum());
umi.use(signerIdentity(dummySigner));

const mintBuilder = mintV1(umi, {
  leafOwner: umiPublicKey(walletAddress),
  merkleTree: umiPublicKey(merkleTreeAddress),
  metadata: {
    name: nftName,
    symbol,
    uri: metadataUri,
    sellerFeeBasisPoints: 0,
    collection: none(),
    creators: [{ address, verified: false, share: 100 }],
  },
});

2.Extract Asset ID from Transaction Logs

cNFTs don't have mint addresses. Extract Asset ID from logs:

// From lib/nft-utils.ts
async function extractCNftAssetId(signature: string) {
  const tx = await connection.getTransaction(signature, {
    commitment: 'confirmed',
    maxSupportedTransactionVersion: 0,
  });

  for (const log of tx.meta.logMessages) {
    const match = log.match(
      /Leaf asset ID: ([1-9A-HJ-NP-Za-km-z]{32,44})/
    );
    if (match) return match[1];
  }
}

3.Sign & Send via LazorKit

LazorKit handles signing with passkey and gas sponsorship:

// From page.tsx
const { signAndSendTransaction } = useWallet();

const signature = await signAndSendTransaction({
  instructions,
  transactionOptions: {
    computeUnitLimit: 400_000,
  },
});

The merkle tree is created once by the platform. Users just mint to it - no accounts created per mint!

What You'll Learn

✓Use Metaplex Bubblegum with LazorKit
✓Mint to existing merkle trees (zero rent!)
✓Extract Asset ID from transaction logs
✓View cNFTs via DAS-compatible explorers

Connect Your Wallet

Use LazorKit to mint compressed NFTs for free

🌳Demo Merkle Tree

HiTxt5DJMYSpwZ7i3Kx5qzYsuAfEWMZMnyGCNokC7Y2u

Capacity: 16,384 cNFTs • Shared by all cookbook users