Solnet C# SDK for Solana

This minimal example demonstrates how to initialize an RPC client, create a wallet, fetch a balance, and construct/send a transaction containing a memo instruction using the TransactionBuilder and ComputeBudgetProgram.

using Solnet.Rpc;
using Solnet.Rpc.Builders;
using Solnet.Rpc.Types;
using Solnet.Programs;
using Solnet.Wallet;

var rpc = ClientFactory.GetClient(Cluster.MainNet);
var wallet = new Wallet();
var from = wallet.GetAccount(0);

// Get balance
var bal = rpc.GetBalance(from.PublicKey);
Console.WriteLine($"Balance: {bal.Result.Value} lamports");

// Send a simple memo transaction
var blockhash = rpc.GetLatestBlockHash();
var tx = new TransactionBuilder()
    .SetRecentBlockHash(blockhash.Result.Value.Blockhash)
    .SetFeePayer(from)
    .AddInstruction(ComputeBudgetProgram.SetComputeUnitLimit(30000))
    .AddInstruction(ComputeBudgetProgram.SetComputeUnitPrice(1000000))
    .AddInstruction(MemoProgram.NewMemo(from, "Hello from Solnet"))
    .Build(from);

var sig = rpc.SendTransaction(tx);
Console.WriteLine($"tx: {sig.Result}");

To create a new token, you must perform a sequence of instructions: create the mint account, initialize it, create a token account for the owner, initialize that account, and finally mint tokens to it.

Required Steps:

1. Rent Exemption: Use rpcClient.GetMinimumBalanceForRentExemption for both TokenProgram.TokenAccountDataSize and TokenProgram.MintAccountDataSize.
2. Create Mint: SystemProgram.CreateAccount with TokenProgram.ProgramIdKey.
3. Initialize Mint: TokenProgram.InitializeMint.
4. Create Token Account: SystemProgram.CreateAccount for the owner's token account.
5. Initialize Token Account: TokenProgram.InitializeAccount.
6. Mint: TokenProgram.MintTo to move supply into the account.

var wallet = new Wallet(MnemonicWords);
var blockHash = rpcClient.GetLatestBlockHash();
var minBalanceForExemptionAcc = rpcClient.GetMinimumBalanceForRentExemption(TokenProgram.TokenAccountDataSize).Result;
var minBalanceForExemptionMint = rpcClient.GetMinimumBalanceForRentExemption(TokenProgram.MintAccountDataSize).Result;

var mintAccount = wallet.GetAccount(21);
var ownerAccount = wallet.GetAccount(10);
var initialAccount = wallet.GetAccount(22);

var tx = new TransactionBuilder()
    .SetRecentBlockHash(blockHash.Result.Value.Blockhash)
    .SetFeePayer(ownerAccount)
    .AddInstruction(ComputeBudgetProgram.SetComputeUnitLimit(30000))
    .AddInstruction(ComputeBudgetProgram.SetComputeUnitPrice(1000000))
    .AddInstruction(SystemProgram.CreateAccount(
        ownerAccount,
        mintAccount,
        minBalanceForExemptionMint,
        TokenProgram.MintAccountDataSize,
        TokenProgram.ProgramIdKey))
    .AddInstruction(TokenProgram.InitializeMint(
        mintAccount.PublicKey,
        2,
        ownerAccount.PublicKey,
        ownerAccount.PublicKey))
    .AddInstruction(SystemProgram.CreateAccount(
        ownerAccount,
        initialAccount,
        minBalanceForExemptionAcc,
        TokenProgram.TokenAccountDataSize,
        TokenProgram.ProgramIdKey))
    .AddInstruction(TokenProgram.InitializeAccount(
        initialAccount.PublicKey,
        mintAccount.PublicKey,
        ownerAccount.PublicKey))
    .AddInstruction(TokenProgram.MintTo(
        mintAccount.PublicKey,
        initialAccount.PublicKey,
        25000,
        ownerAccount))
    .AddInstruction(MemoProgram.NewMemo(initialAccount, "Hello from Sol.Net"))
    .Build(new List<Account>{ ownerAccount, mintAccount, initialAccount });

The Solnet.KeyStore project allows for secure storage of keys, seeds, and mnemonics using the Web3 Secret Storage Definition.

• SecretKeyStoreService: Use EncryptAndGenerateDefaultKeyStoreAsJson to encrypt data and generate a JSON string. Use KeyStore.DecryptKeyStoreFromJson to recover the data using the correct password.
• SolanaKeyStoreService: Use RestoreKeystore to read keys generated by the solana-keygen CLI tool from a file path using a passphrase.

// Secret KeyStore Service
var secretKeyStoreService = new SecretKeyStoreService();
var jsonString = secretKeyStoreService.EncryptAndGenerateDefaultKeyStoreAsJson(password, data, address);

try
{
    var decrypted = KeyStore.DecryptKeyStoreFromJson(password, jsonString);
}
catch (Exception)
{
    Console.WriteLine("Invalid password!");
}

// Solana KeyStore Service
var solanaKeyStoreService = new SolanaKeyStoreService();
var wallet = solanaKeyStoreService.RestoreKeystore(filePath, passphrase);

Solnet provides several ways to initialize accounts and wallets depending on your source material (secret keys, mnemonics, or derivation paths).

• From Secret Key: Use Account.FromSecretKey(string) to create an account directly from a byte array string.
• Phantom-compatible Wallet: Initialize a Wallet with a mnemonic and a WordList. Use wallet.GetAccount(index) to derive specific accounts. By default, this follows Phantom's derivation pattern.
• solana-keygen compatible Wallet: Initialize a Wallet using SeedMode.Bip39 and a passphrase. Use the .Account property to access the account, as solana-keygen uses a fixed derivation path.
• New Wallet: Generate a new mnemonic using the Mnemonic class and pass it to a new Wallet instance.

// Initialize a keypair from a secret key
var account = Account.FromSecretKey("");

// Initialize a wallet (Phantom-compatible by default)
var wallet = new Wallet("mnemonic words ...", WordList.English);
var account = wallet.GetAccount(10);

// Initialize a wallet compatible with solana-keygen
var wallet = new Wallet("mnemonic words ...", WordList.English, "passphrase", SeedMode.Bip39);
var account = wallet.Account;

// Generating new wallets
var newMnemonic = new Mnemonic(WordList.English, WordCount.Twelve);
var wallet = new Wallet(newMnemonic);