🎮 Game Guess - IOTA Blockchain dApp

A decentralized number guessing game built on the IOTA blockchain network. Players need to guess 4 secret numbers correctly to receive a Flag NFT.

Contract Address

• Network: testnet
• Package ID: 0x3062c7a482e441a030860cf496ac40a1d2de08d0938d77154276b033cf985814
• Explorer: View on Explorer

✨ Features

• 🔗 Connect IOTA wallet via IOTA dApp Kit
• 🎯 Submit your guess to the smart contract
• 📦 Receive GuessBox NFT after each guess
• 🏆 Get Flag NFT when guessing correctly
• ⛓️ Fully on-chain, transparent and immutable
• 🎨 Modern UI with Tailwind CSS

🛠️ Tech Stack

• Frontend: Next.js 16, React 19, TypeScript
• Blockchain: IOTA Network (Devnet)
• Smart Contract: Move Language
• UI: Tailwind CSS, Radix UI
• Web3: @iota/dapp-kit, @iota/iota-sdk

📋 Prerequisites

• Node.js 18+
• IOTA CLI installed
• IOTA wallet (supporting IOTA dApp Kit)
• IOTA test tokens (for devnet)

🚀 Installation

1. Clone and install dependencies

git clone <repository-url>
cd GameGuess
npm install --legacy-peer-deps

Note: Use --legacy-peer-deps to avoid peer dependency conflicts between React 19 and other libraries.

2. Deploy Smart Contract

npm run iota-deploy

After successful deployment, you'll receive a Package ID. Copy this ID!

3. Update configuration

Open lib/config.ts and replace PACKAGE_ID with your Package ID:

export const PACKAGE_ID = "0x..."; // Replace with your Package ID

4. Run the application

npm run dev

Open your browser and visit http://localhost:3000

🎮 How to Play

1. Connect Wallet: Click "Connect Wallet" and select your IOTA wallet
2. Enter Guess: Input 4 numbers (each number from 0-255)
3. Submit Guess: Click "Submit Guess" to send to blockchain
4. Get GuessBox ID: After successful transaction, you'll receive a GuessBox object ID
5. Check Result: Enter GuessBox ID and click "Check" to see the result
6. Receive Flag: If correct, you'll receive a Flag NFT! 🎉

🧩 Smart Contract

Structure

module game_guess::guess {
    // Struct storing player's guess
    public struct GuessAttempt has store {
        number1: u16,
        number2: u16,
        number3: u16,
        number4: u16,
    }

    // NFT containing the guess
    public struct GuessBox has key, store {
        id: UID,
        guess: GuessAttempt,
    }

    // Reward NFT when guessed correctly
    public struct Flag has key, store {
        id: UID,
        user: address,
        solved_at: u64,
    }
}

Main Functions

submit_guess(number1: u16, number2: u16, number3: u16, number4: u16)

• Submit your guess with 4 numbers of type u16 (0-65535)
• Creates a GuessBox NFT containing your guess
• GuessBox is transferred to your wallet address

check_guess(guessbox: &GuessBox)

• Checks if the guess is correct by comparing BCS encoding
• If correct: Creates and transfers Flag NFT to you
• If incorrect: Transaction fails with error EIncorrectGuess

How It Works

The smart contract uses BCS (Binary Canonical Serialization) for comparison:

• Your guess is serialized into bytes
• Compared with the secret hex string: x"0a0014001e002800"
• Correct answer: [10, 20, 30, 40]

📁 Project Structure

GameGuess/
├── app/                          # Next.js App Router
│   ├── layout.tsx               # Root layout with providers
│   ├── page.tsx                 # Main page - Game UI
│   └── globals.css              # Global styles
├── components/                   # React components
│   └── Provider.tsx             # IOTA providers (QueryClient, WalletProvider)
├── contract/                     # Smart contracts
│   └── game_guess/
│       ├── sources/
│       │   └── game_guess.move  # Move smart contract
│       ├── Move.toml            # Move package config
│       └── build/               # Compiled contract (auto-generated)
├── hooks/                        # Custom React hooks
│   └── useContract.ts           # Hook for contract interaction
├── lib/                          # Utilities
│   └── config.ts                # Configuration (PACKAGE_ID, network, etc.)
├── scripts/                      # Scripts
│   ├── iota-deploy-wrapper.js   # Contract deployment script
│   └── iota-generate-prompt-wrapper.js
├── next.config.ts               # Next.js config
├── tailwind.config.ts           # Tailwind config
└── package.json                 # Dependencies

🔧 Available Scripts

# Development
npm run dev          # Run dev server

# Build
npm run build        # Build for production
npm run start        # Run production server

# Smart Contract
npm run iota-deploy  # Deploy contract to IOTA network

# Linting
npm run lint         # Run ESLint

🐛 Troubleshooting

Error: "Cannot find module @iota/dapp-kit"

npm install --legacy-peer-deps

Error: "Package not deployed" or transaction fails

• Make sure you've run npm run iota-deploy
• Check if PACKAGE_ID in lib/config.ts is correct
• Verify you're connected to the correct network (devnet)

Error: "Insufficient gas" or transaction rejected

• Ensure your wallet has enough IOTA test tokens
• Get test tokens from IOTA Devnet Faucet

Guess is incorrect but you're sure it's right

• Double-check the answer: 10, 20, 30, 40 (not 7, 13, 42, 99)
• Make sure the number order is correct
• Verify the GuessBox ID is accurate

💡 Hints

The answer consists of 4 special numbers:

• 🔢 Nice round numbers
• 📊 Following an increasing pattern
• 🎯 Within the range 0-255
• 🔐 Encoded as: x"0a0014001e002800"

Answer: [10, 20, 30, 40] 😉

🔐 Security

• ✅ Smart contract written in Move - a resource-safe language
• ✅ Answer is encoded in bytecode, not easily readable
• ✅ Uses BCS serialization for validation
• ✅ No backdoors or admin functions
• ⚠️ This is a demo dApp on testnet, not for production use

📚 References

• IOTA Documentation
• Move Language Book
• IOTA dApp Kit
• Next.js Documentation

📝 License

MIT License - See LICENSE file for more details

👨‍💻 Development

This project was created as a demo to learn how to build dApps on the IOTA blockchain.

---

Have fun playing! 🎮🎉