Building on Quanta: Developer Guide

Welcome to Quanta Chain development! This guide will walk you through everything you need to start building quantum-resistant decentralized applications (dApps) on Quanta.

Why Build on Quanta?

Quanta Chain offers unique advantages for developers:

Future-proof security - Post-quantum cryptography protects your users
Familiar tooling - Rust-based development with modern APIs
High performance - Optimized consensus for fast transactions
Active community - Growing ecosystem of builders and contributors

Getting Started

Prerequisites

Before you begin, make sure you have:

• Rust (1.70+) - Install Rust
• Node.js (18+) - For frontend development
• Git - For cloning repositories
• Basic blockchain knowledge - Understanding of transactions, blocks, and consensus

1. Set Up Your Development Environment

Clone the Quanta repository:

git clone https://github.com/quantachain/quanta.git
cd quanta

Build the Quanta node:

cargo build --release

Run a local testnet node:

./target/release/quanta --testnet

2. Get Testnet QUA

Visit our faucet to get testnet QUA tokens for development:

# Request testnet tokens
curl -X POST https://faucet.quantachain.io/request \
  -H "Content-Type: application/json" \
  -d '{"address": "YOUR_QUANTA_ADDRESS"}'

3. Create Your First Transaction

Here's a simple example of creating and signing a transaction:

use quanta_core::{Transaction, Wallet};
use falcon512::SecretKey;

// Load your wallet
let wallet = Wallet::from_file("wallet.json")?;

// Create a transaction
let tx = Transaction {
    sender: wallet.address(),
    recipient: "qua1recipient_address_here".parse()?,
    amount: 100_000_000, // 1 QUA (8 decimals)
    fee: 1_000_000,      // 0.01 QUA
    nonce: wallet.get_nonce(),
    data: vec![],
};

// Sign with Falcon-512
let signature = wallet.sign_transaction(&tx)?;
let signed_tx = tx.with_signature(signature);

// Broadcast to network
client.broadcast_transaction(signed_tx).await?;

Core Concepts

Quantum-Resistant Addresses

Quanta addresses are derived from Falcon-512 public keys:

Format: qua1<bech32-encoded-public-key-hash>
Example: qua1qyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp

Key differences from traditional blockchains:

• Longer addresses (~60 characters vs ~40)
• Falcon-512 public key hashing
• Bech32 encoding for error detection

Transaction Structure

pub struct Transaction {
    pub sender: Address,
    pub recipient: Address,
    pub amount: u64,
    pub fee: u64,
    pub nonce: u64,
    pub data: Vec<u8>,
    pub signature: Signature, // Falcon-512 signature
}

Block Structure

pub struct Block {
    pub header: BlockHeader,
    pub transactions: Vec<Transaction>,
    pub miner_signature: Signature,
}

pub struct BlockHeader {
    pub version: u32,
    pub previous_hash: Hash,
    pub merkle_root: Hash,
    pub timestamp: u64,
    pub difficulty: u64,
    pub nonce: u64,
}

Building a Simple dApp

Let's build a basic token transfer application:

Backend (Rust)

use quanta_sdk::Client;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Connect to Quanta node
    let client = Client::connect("http://localhost:8545").await?;
    
    // Get account balance
    let balance = client.get_balance("qua1your_address").await?;
    println!("Balance: {} QUA", balance as f64 / 1e8);
    
    // Send transaction
    let tx_hash = client.send_transaction(
        "qua1recipient",
        100_000_000, // 1 QUA
        None,        // Optional data
    ).await?;
    
    println!("Transaction sent: {}", tx_hash);
    
    Ok(())
}

Frontend (TypeScript + React)

import { QuantaProvider, useWallet } from '@quanta/wallet-adapter';

function TransferForm() {
  const { address, sendTransaction } = useWallet();
  
  const handleTransfer = async (recipient: string, amount: number) => {
    try {
      const txHash = await sendTransaction({
        to: recipient,
        amount: amount * 1e8, // Convert to base units
      });
      
      console.log('Transaction sent:', txHash);
    } catch (error) {
      console.error('Transfer failed:', error);
    }
  };
  
  return (
    <div>
      <h2>Send QUA</h2>
      {/* Transfer form UI */}
    </div>
  );
}

Advanced Topics

Smart Contracts (Coming Soon)

Quanta is developing a smart contract layer with:

• Quantum-resistant execution environment
• Rust-based contract language
• WebAssembly (WASM) runtime
• Gas-efficient PQC operations

Wallet Integration

Integrate the Quanta browser extension:

// Detect Quanta wallet
if (window.quanta) {
  const accounts = await window.quanta.request({
    method: 'quanta_requestAccounts'
  });
  
  console.log('Connected:', accounts[0]);
}

Running a Validator Node

Contribute to network security by running a validator:

# Generate validator keys
quanta validator keygen --output validator_keys.json

# Start validator node
quanta --validator \
  --validator-keys validator_keys.json \
  --network mainnet

Best Practices

1. Key Management

🔐 Never expose private keys in client-side code
🔐 Use hardware wallets for production applications
🔐 Implement key rotation for long-lived applications

2. Transaction Handling

✅ Always verify signatures before processing
✅ Implement nonce management to prevent replay attacks
✅ Set appropriate fees based on network congestion

3. Error Handling

match client.send_transaction(tx).await {
    Ok(hash) => println!("Success: {}", hash),
    Err(e) => match e {
        Error::InsufficientFunds => eprintln!("Not enough QUA"),
        Error::InvalidSignature => eprintln!("Signature verification failed"),
        Error::NetworkError(msg) => eprintln!("Network error: {}", msg),
        _ => eprintln!("Unknown error: {}", e),
    }
}

Resources

Documentation

• API Reference
• GitHub Repository
• Example Projects

Community

• Discord - Get help from developers
• Telegram - Real-time discussions
• GitHub Discussions - Technical Q&A

Tools

• Testnet Faucet - Get testnet QUA
• Block Explorer - View transactions and blocks (coming soon)
• Wallet Extension - Browser wallet (coming soon)

Next Steps

Ready to start building?

1. Join our Discord and introduce yourself
2. Get testnet tokens from the faucet
3. Build something cool and share it with the community
4. Contribute to Quanta - we're open source!

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Questions? Reach out to our developer community on Discord or check out our documentation.