CIP-68 Showcase

This Repository shows how to create a Cardano CIP-68 NFT using CardanoSharp

CIP-68 Cardano NFTs are much more powerful then the previous CIP-25 NFT standard as CIP-68 NFTs can be read and mutated by smart contracts.

Developers can write custom smart contract flows for these NFTs. But in this example, we will use what is called an "Always Fail" script. Meaning when a reference NFT is locked in the smart contract, the data cannot change.

This address contains the script we will be using: addr1w93wm24j6fcesyfs8ed733jvct3pf2mazt7l8kxrew6ldzccmj96w

1. Generate a Wallet or use an existing one

Wallet wallet = new Wallet();
wallet.GenerateWallet();

2. Initialize Blockfrost and the Policy Id

BlockfrostService blockfrostService = new BlockfrostService();
await blockfrostService.Initialize();

DateTime lockTime = DateTime.Now.AddYears(1);
var nativeScript = WalletService.GetPolicyScriptBuilder(wallet, lockTime);
var policyId = WalletService.GetPolicyId(wallet, lockTime).ToStringHex();

3. Initialize Address and Asset Name Data

string assetName = "HelloWorld";
string address = wallet.address!;
string scriptAddress = "addr1w93wm24j6fcesyfs8ed733jvct3pf2mazt7l8kxrew6ldzccmj96w";

Address paymentAddressObject = new Address(address!);
Address scriptAddressObject = new Address(scriptAddress);

4. Create Transaction Body

TransactionBodyBuilder transactionBodyBuilder = (TransactionBodyBuilder)
    TransactionBodyBuilder.Create;

5. Create User and Reference Asset Name Tokens

string referenceAssetNameHexPrefix = AssetLabelUtility.GetAssetLabelHex(100); // Asset Label (100) in CIP-67 format;
string userAssetNameHexPrefix = AssetLabelUtility.GetAssetLabelHex(222); // Asset Label (222) in CIP-67 format;

string userAssetNameHex = $"{userAssetNameHexPrefix}{assetName}";
string referenceAssetNameHex = $"{referenceAssetNameHexPrefix}{assetName}";
string referenceAssetFullNameHex = $"{policyId}{referenceAssetNameHex}";

6. Calculate CIP-68 Mint NFTs

TokenBundleBuilder totalMintTokenBundleBuilder = (TokenBundleBuilder)TokenBundleBuilder.Create;
TokenBundleBuilder referenceMintTokenBundleBuilder = (TokenBundleBuilder)TokenBundleBuilder.Create;
TokenBundleBuilder userMintTokenBundleBuilder = (TokenBundleBuilder)TokenBundleBuilder.Create;

totalMintTokenBundleBuilder.AddToken(
    policyId.HexToByteArray(),
    referenceAssetNameHex.HexToByteArray(),
    1
);
totalMintTokenBundleBuilder.AddToken(
    policyId.HexToByteArray(),
    userAssetNameHex.HexToByteArray(),
    1
);
referenceMintTokenBundleBuilder.AddToken(
    policyId.HexToByteArray(),
    referenceAssetNameHex.HexToByteArray(),
    1
);
userMintTokenBundleBuilder.AddToken(
    policyId.HexToByteArray(),
    userAssetNameHex.HexToByteArray(),
    1
);

7. Calculate Datums

// Calculate the Reference NFT Datum Metadata - Update this field to add data for your NFT!
// Plutus Data 6.121[metadata, version, extra]
// 6.121[metadata, version, extra] = constructor 0, fields [{}, 1, #6.121([])]
PlutusDataMap metadata = new PlutusDataMap();
PlutusDataInt version = new PlutusDataInt() { Value = 1 };
PlutusDataConstr extra = new PlutusDataConstr()
{
    Value = new PlutusDataArray() { Value = new IPlutusData[] { } },
    Alternative = 0
};

IPlutusData[] metadataDatum = new IPlutusData[] { metadata, version, extra };
PlutusDataArray metadataDatumArray = new PlutusDataArray() { Value = metadataDatum };
PlutusDataConstr constr = new PlutusDataConstr() { Value = metadataDatumArray, Alternative = 0 };
DatumOption datum = new DatumOption() { Data = constr };

8. Create Transaction Outputs

// 8.1) Create Reference Token Output
TransactionOutputBuilder transactionReferenceOutputBuilder = (TransactionOutputBuilder)
    TransactionOutputBuilder.Create
        .SetAddress(scriptAddress.ToBytes())
        .SetTransactionOutputValue(
            new TransactionOutputValue
            {
                Coin = (ulong)(5 * CardanoService.adaToLovelace),
                MultiAsset = referenceMintTokenBundleBuilder.Build()
            }
        )
        .SetDatumOption(datum);

var transactionScriptOutput = transactionReferenceOutputBuilder.Build();
transactionReferenceOutputBuilder.SetTransactionOutputValue(
    new TransactionOutputValue
    {
        Coin = transactionScriptOutput.CalculateMinUtxoLovelace(),
        MultiAsset = referenceMintTokenBundleBuilder.Build()
    }
);

// 8.2) Create User Token Output
transactionBodyBuilder.AddOutput(
    paymentAddressObject.GetBytes(),
    userMintTokenBundleBuilder.Build().CalculateMinUtxoLovelace(),
    userMintTokenBundleBuilder
);

9. Select Inputs and change using the largest first Coin Selection Algorithm

List<Utxo> utxos = await blockfrostService.GetUTXOs(
    new List<string> { paymentAddressObject.ToString() }
);
CoinSelection? coinSelection = transactionBodyBuilder.UseLargestFirst(
    utxos,
    address,
    mint: totalMintTokenBundleBuilder,
    feeBuffer: (ulong)CardanoService.adaOnlyMinUTXO
);
if (coinSelection == null)
{
    throw new Exception("Coin Selection Error");
}

foreach (TransactionOutput changeOutput in coinSelection.ChangeOutputs)
    transactionBodyBuilder.AddOutput(changeOutput);

foreach (TransactionInput input in coinSelection.Inputs)
    transactionBodyBuilder.AddInput(input);

10. Build the Transaction

transactionBodyBuilder
    .SetMint(totalMintTokenBundleBuilder)
    .SetTtl(blockfrostService.blockfrostData.currentSlot + 1 * 60 * 15) // 15 minutes
    .SetFee(0);

11. Create Transaction Witnesses

TransactionWitnessSetBuilder transactionWitnessSetBuilder = (TransactionWitnessSetBuilder)
    TransactionWitnessSetBuilder.Create;
transactionWitnessSetBuilder
    .AddVKeyWitness(wallet.publicKey, wallet.privateKey)
    .SetScriptAllNativeScript(nativeScript);

12. Calculate Final Fee

var fee = transaction.CalculateAndSetFee(
    blockfrostService.blockfrostData.minFeeA,
    blockfrostService.blockfrostData.minFeeB
);

ulong lastOutputChangeBalance = transaction.TransactionBody.TransactionOutputs.Last().Value.Coin;
transaction.TransactionBody.TransactionOutputs.Last().Value.Coin =
    lastOutputChangeBalance - (ulong)fee;

13. Submit Transaction

string? transactionId = await blockfrostService.SubmitTransaction(transaction);
if (transactionId != null)
    Console.WriteLine(
        $"Transaction Submitted Successfully! TransactionId: {transactionId}. TransactionIndex: 0"
    );
else
    Console.WriteLine($"Transaction Failed!");