Tutorial: Distribuisci il Tuo Primo Token SAVITRI-20

Questo tutorial ti guida nel processo di distribuzione di un token fungibile sulla Savitri Network utilizzando l'SDK.

Prerequisiti

• Un lightnode Savitri in esecuzione (vedi Avvio Rapido)
• Toolchain Rust installata
• Un wallet finanziato (usa il faucet del testnet)

1. Configurazione del Progetto

Crea un nuovo progetto Rust:

cargo new my-savitri-token
cd my-savitri-token

Aggiungi le dipendenze al Cargo.toml:

[dependencies]
savitri-sdk = { path = "../savitri-sdk" }
tokio = { version = "1", features = ["full"] }
anyhow = "1"
hex = "0.4"

2. Crea un Wallet

use savitri_sdk::{Wallet, RpcClient};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // Create or import a wallet
    let wallet = Wallet::new();
    println!("Your address: {}", wallet.address());

    // Connect to local node
    let client = RpcClient::from_url("http://localhost:8545")?;

    // Check if node is running
    let health = client.health().await?;
    println!("Connected to {} ({})", health.service, health.mode);

    Ok(())
}

3. Finanzia il Tuo Wallet

Richiedi token testnet tramite il faucet:

let claim = client.faucet_claim(wallet.address()).await?;
println!("Received {} SAVT (tx: {})", claim.amount, claim.tx_hash);

// Wait for confirmation
tokio::time::sleep(std::time::Duration::from_secs(10)).await;

// Verify balance
let account = client.get_account(wallet.address()).await?;
println!("Balance: {} (nonce: {})", account.balance, account.nonce);

4. Distribuisci il Contratto Token

La distribuzione del token è una transazione con to = None e i dati di inizializzazione in data:

use savitri_sdk::TransactionBuilder;

// Encode token initialization parameters
fn encode_token_init(name: &str, symbol: &str, initial_supply: u128) -> Vec<u8> {
    let mut data = b"initialize_savitri20".to_vec();
    data.push(0); // separator

    // Name (length-prefixed)
    data.extend_from_slice(&(name.len() as u32).to_le_bytes());
    data.extend_from_slice(name.as_bytes());

    // Symbol (length-prefixed)
    data.extend_from_slice(&(symbol.len() as u32).to_le_bytes());
    data.extend_from_slice(symbol.as_bytes());

    // Initial supply (u128 LE)
    data.extend_from_slice(&initial_supply.to_le_bytes());

    data
}

// Build deploy transaction
let nonce = client.get_nonce(wallet.address()).await?;

let deploy_data = encode_token_init(
    "My Token",                              // name
    "MTK",                                   // symbol
    1_000_000_000_000_000_000_000_000,       // 1M tokens (18 decimals)
);

let deploy_tx = TransactionBuilder::new()
    // No .to() — indicates contract deployment
    .data(deploy_data)
    .value(0)
    .nonce(nonce)
    .fee(5_000_000_000_000_000) // 0.005 SAVT contract fee
    .build_and_sign(&wallet)?;

println!("Deploy TX built. Contract will be created at a derived address.");

5. Interagisci con il Token

Una volta distribuito, usa il ContractClient per interagire:

use savitri_sdk::ContractClient;

let contract = ContractClient::from_url_and_wallet(
    "http://localhost:8545",
    wallet.clone(),
)?;

// Transfer tokens
let tx_hash = contract.call_contract(
    &token_contract_address,
    b"transfer",
    &encode_transfer(&recipient_address, 1000_000_000_000_000_000), // 1000 tokens
    Some(0),
).await?;
println!("Transfer TX: {}", tx_hash);

6. Verifica il Saldo del Token

// Via RPC
let balance = client.call_raw(
    "account_getTokenBalance",
    serde_json::json!([wallet.address(), token_contract_address]),
).await?;
println!("Token balance: {}", balance);

Riferimento Rapido agli Standard dei Token

Standard	Caso d'Uso	Funzioni Principali
SAVITRI-20	Token fungibili	transfer, approve, transferFrom
SAVITRI-721	NFT	mint, transferFrom, tokenURI
SAVITRI-1155	Multi-asset	safeTransferFrom, balanceOfBatch

Riferimento alle Commissioni

Operazione	Commissione (SAVT)
Distribuzione token	0.005
Trasferimento token	0.005
Approvazione token	0.005
Conio NFT	0.005
Trasferimento batch	0.005

Importi e Decimali

Tutti i token Savitri usano 18 decimali:

1 token     = 1_000_000_000_000_000_000  (10^18)
0.001 token = 1_000_000_000_000_000      (10^15)
1M tokens   = 1_000_000_000_000_000_000_000_000  (10^24)

Passi Successivi

• Riferimento SAVITRI-20 -- API completa per token fungibili
• Runtime dei Contratti -- Come vengono eseguiti i contratti
• Governance -- Proponi modifiche ai parametri del token