🎫 Euro Voucher NFT System on Monad Blockchain

A decentralized application (dApp) for purchasing, managing, and redeeming Euro-denominated vouchers as NFTs on the Monad blockchain.

📋 Table of Contents

Overview
Euro Banknote Gallery
Features
Live Demo
Smart Contract
Architecture
Installation
Usage
Smart Contract Functions
NFT Metadata
Tech Stack
License

🌟 Overview

The Euro Voucher NFT System allows users to:

Purchase Euro-denominated vouchers (5€, 10€, 20€, 50€, 100€, 500€) using MON tokens
Receive ERC-721 NFTs representing their vouchers
Transfer vouchers between wallets
Redeem vouchers when needed
Track purchase history and timestamps

Each NFT voucher contains:

Euro value
Purchase price in MON
Unique voucher ID
Purchase timestamp
Redemption status
Beautiful euro banknote imagery

💶 Euro Banknote Gallery

Available Denominations

Denomination	Image	Price (MON)
5€		100 MON
10€		200 MON
20€		300 MON
50€		500 MON
100€		1,000 MON
500€		5,000 MON

✨ Features

🎨 Frontend Features

✅ MetaMask wallet connection
✅ Automatic Monad network detection/switching
✅ Visual voucher selection (6 denominations)
✅ Real-time transaction status
✅ Voucher details reader
✅ Responsive neon-themed UI
✅ Euro banknote images on each voucher

🔐 Smart Contract Features

✅ ERC-721 compliant NFTs
✅ Dynamic pricing system
✅ Ownership tracking
✅ Redemption mechanism
✅ Transfer functionality
✅ Owner-only admin functions
✅ Event emission for tracking

🖼️ NFT Features

✅ On-chain metadata
✅ Unique voucher IDs
✅ Purchase timestamps
✅ Euro banknote images
✅ QR code data support

🌐 Live Demo

Frontend: https://euro-voucher-frontend.vercel.app

Metadata API: https://euro-voucher-metadata.vercel.app

Explorer: View Contract on Monad Explorer

📜 Smart Contract

const VAULT_ADDRESS = 0xE00454506f50ac31A0b87324513e28f77Db2a8F9 const SWAP_ROUTER_ADDRESS = 0x334cf8898EecCC0B98420E6910A3ae83A00b32e0 Contract Address: 0xa4d064E4ac881234961C076d314Abf9ac8d4E4BB

Network: Monad Mainnet (Chain ID: 143)

Token Standard: ERC-721

Name: Euro Voucher NFT

Symbol: EVNFT

🏗️ Architecture

┌─────────────────┐
│   User Wallet   │
│   (MetaMask)    │
└────────┬────────┘
         │
         ↓
┌─────────────────┐      ┌──────────────────┐
│    Frontend     │─────→│ Smart Contract   │
│   (Vercel)      │      │   (Monad Chain)  │
└─────────────────┘      └────────┬─────────┘
                                  │
                                  ↓
                         ┌──────────────────┐
                         │  Metadata API    │
                         │   (Vercel)       │
                         └──────────────────┘

Components:

Frontend (HTML/JS/Tailwind)
- User interface for buying/reading vouchers
- Web3.js integration for blockchain interaction
- Deployed on Vercel
Smart Contract (Solidity)
- ERC-721 NFT implementation
- Voucher logic and state management
- Deployed on Monad blockchain
Metadata API (Node.js/Express)
- Serves NFT metadata (JSON)
- Returns euro banknote images
- OpenSea-compatible format

🚀 Installation

Prerequisites

Node.js v16+
MetaMask browser extension
Git

Clone Repository

git clone https://github.com/yourusername/euro-voucher-nft.git
cd euro-voucher-nft

Frontend Setup

cd frontend
# No build required - it's a static HTML file
# Just open index.html in browser or deploy to Vercel
vercel --prod

Metadata API Setup

cd metadata-api
npm install
npm start

# Or deploy to Vercel
vercel --prod

📖 Usage

1. Connect Wallet

Click "CONNECT TO MONAD"
Approve MetaMask connection
Switch to Monad network if needed

2. Purchase Voucher

Select denomination (5€ - 500€)
Click "BUY" button
Confirm transaction in MetaMask
Receive NFT in your wallet

3. Read Voucher

Enter Token ID
Click "Read Voucher"
View all voucher details

4. Transfer Voucher

Use MetaMask to send NFT
Or call transferFrom() function

5. Redeem Voucher

Call redeemVoucher(tokenId) when ready to use

🔧 Smart Contract Functions

📖 Read Functions (View)

`getVoucher(uint256 tokenId)`

Get complete voucher information.

Returns:

euroValue - Denomination (5, 10, 20, 50, 100, 500)
pricePaidMON - Price paid in MON (wei)
buyer - Wallet address of purchaser
purchaseTimestamp - Unix timestamp
redeemed - Redemption status (bool)
voucherId - Unique voucher ID string

Example:

const voucher = await contract.methods.getVoucher(1).call();
console.log(voucher);
// Output: [50, "500000000000000000000", "0xABC...", 1737380000, false, "VOC-123"]

`getPrice(uint256 euroValue)`

Get current price for a denomination.

Parameters:

euroValue - Euro denomination (5, 10, 20, 50, 100, 500)

Returns:

price - Price in MON (wei)

Example:

const price = await contract.methods.getPrice(50).call();
console.log(web3.utils.fromWei(price, 'ether')); // "500"

`getVouchersByOwner(address owner)`

Get all token IDs owned by an address.

Parameters:

owner - Wallet address

Returns:

uint256[] - Array of token IDs

Example:

const tokens = await contract.methods.getVouchersByOwner("0xYourAddress").call();
console.log(tokens); // [1, 5, 12, 25]

`balanceOf(address owner)`

Get number of vouchers owned by address.

Example:

const balance = await contract.methods.balanceOf("0xYourAddress").call();
console.log(balance); // 4

`ownerOf(uint256 tokenId)`

Get owner of a specific token.

Example:

const owner = await contract.methods.ownerOf(1).call();
console.log(owner); // "0xABC..."

`isVoucherValid(uint256 tokenId)`

Check if voucher exists and is not redeemed.

Returns:

bool - True if valid and unredeemed

Example:

const valid = await contract.methods.isVoucherValid(1).call();
console.log(valid); // true

`getQRCodeData(uint256 tokenId)`

Get QR code data string for voucher.

Returns:

string - QR code data

Example:

const qr = await contract.methods.getQRCodeData(1).call();
console.log(qr); // "EURO_VOUCHER:1:50:VOC-123..."

`getVoucherStats(uint256 euroValue)`

Get statistics for a denomination.

Returns:

totalMinted - Total vouchers of this value
currentPrice - Current price in MON

Example:

const stats = await contract.methods.getVoucherStats(50).call();
console.log(stats); // [15, "500000000000000000000"]

`tokenURI(uint256 tokenId)`

Get metadata URI for NFT (OpenSea compatible).

Returns:

string - Metadata URL

Example:

const uri = await contract.methods.tokenURI(1).call();
console.log(uri); 
// "https://euro-voucher-metadata.vercel.app/metadata/1"

`totalSupply()`

Get total number of vouchers minted.

Example:

const supply = await contract.methods.totalSupply().call();
console.log(supply); // 42

`getContractBalance()`

Get contract's MON balance.

Example:

const balance = await contract.methods.getContractBalance().call();
console.log(web3.utils.fromWei(balance, 'ether')); // "5000"

✍️ Write Functions (Payable/Nonpayable)

`purchaseVoucher(uint256 euroValue, string voucherId)` 💰

Purchase a new voucher NFT.

Parameters:

euroValue - Denomination (5, 10, 20, 50, 100, 500)
voucherId - Unique voucher ID string

Payable: Must send exact MON amount

Example:

const price = await contract.methods.getPrice(50).call();
await contract.methods.purchaseVoucher(50, "VOC-123").send({
  from: userAddress,
  value: price
});

`redeemVoucher(uint256 tokenId)`

Mark voucher as redeemed (only owner can redeem).

Example:

await contract.methods.redeemVoucher(1).send({ from: userAddress });

`transferFrom(address from, address to, uint256 tokenId)`

Transfer voucher to another wallet.

Example:

await contract.methods.transferFrom(
  userAddress,
  "0xRecipient...",
  1
).send({ from: userAddress });

`safeTransferFrom(address from, address to, uint256 tokenId)`

Safely transfer voucher (checks if recipient can receive NFTs).

Example:

await contract.methods.safeTransferFrom(
  userAddress,
  "0xRecipient...",
  1
).send({ from: userAddress });

`approve(address to, uint256 tokenId)`

Approve another address to transfer your voucher.

Example:

await contract.methods.approve("0xSpender...", 1).send({ 
  from: userAddress 
});

`setApprovalForAll(address operator, bool approved)`

Approve/revoke operator to manage all your vouchers.

Example:

await contract.methods.setApprovalForAll("0xOperator...", true).send({
  from: userAddress
});

👑 Owner-Only Functions

`updatePrice(uint256 euroValue, uint256 newPrice)`

Update price for a denomination.

Example:

await contract.methods.updatePrice(50, web3.utils.toWei("600", "ether")).send({
  from: ownerAddress
});

`withdraw()`

Withdraw all contract balance to owner.

Example:

await contract.methods.withdraw().send({ from: ownerAddress });

`withdrawTo(address payable to, uint256 amount)`

Withdraw specific amount to address.

Example:

await contract.methods.withdrawTo(
  "0xRecipient...",
  web3.utils.toWei("1000", "ether")
).send({ from: ownerAddress });

`transferOwnership(address newOwner)`

Transfer contract ownership.

Example:

await contract.methods.transferOwnership("0xNewOwner...").send({
  from: ownerAddress
});

🎨 NFT Metadata

Metadata Structure

{
  "name": "Euro Voucher - 50€",
  "description": "A 50 Euro voucher NFT on Monad blockchain. Purchase Date: 1/20/2026. Status: Active",
  "image": "https://files.catbox.moe/4jezdg.jpeg",
  "attributes": [
    {
      "trait_type": "Euro Value",
      "value": 50
    },
    {
      "trait_type": "Price Paid (MON)",
      "value": 500
    },
    {
      "trait_type": "Status",
      "value": "Active"
    },
    {
      "trait_type": "Purchase Date",
      "value": "2026-01-20"
    },
    {
      "trait_type": "Voucher ID",
      "value": "VOC-1737380000-XYZ123"
    }
  ]
}

Euro Banknote Images

Denomination	Preview	Image URL
5€		https://files.catbox.moe/mszp1d.jpeg
10€		https://files.catbox.moe/otcljk.jpeg
20€		https://files.catbox.moe/c11h9p.jpeg
50€		https://files.catbox.moe/4jezdg.jpeg
100€		https://files.catbox.moe/qlf6vq.jpeg
500€		https://files.catbox.moe/ir84ab.jpeg

🎯 Events

The contract emits these events for tracking:

`VoucherPurchased`

event VoucherPurchased(
    uint256 indexed tokenId,
    address indexed buyer,
    uint256 euroValue,
    uint256 pricePaid,
    string voucherId,
    uint256 timestamp
);

`VoucherRedeemed`

event VoucherRedeemed(
    uint256 indexed tokenId,
    address indexed redeemer,
    uint256 euroValue,
    uint256 timestamp
);

`VoucherTransferred`

event VoucherTransferred(
    uint256 indexed tokenId,
    address indexed from,
    address indexed to,
    uint256 timestamp
);

`PriceUpdated`

event PriceUpdated(
    uint256 euroValue,
    uint256 oldPrice,
    uint256 newPrice
);

💻 Tech Stack

Frontend

HTML5
JavaScript (ES6+)
Tailwind CSS
Web3.js v1.10.4
JetBrains Mono Font

Smart Contract

Solidity ^0.8.20
OpenZeppelin Contracts
ERC-721 Standard
Ownable Pattern

Backend

Node.js
Express.js
CORS enabled

Deployment

Vercel (Frontend & API)
Monad Blockchain (Smart Contract)

Tools

MetaMask
Remix IDE
Monad Explorer

📊 Pricing Structure

Euro Value	Price (MON)	Wei Value
5€	100 MON	100000000000000000000
10€	200 MON	200000000000000000000
20€	300 MON	300000000000000000000
50€	500 MON	500000000000000000000
100€	1,000 MON	1000000000000000000000
500€	5,000 MON	5000000000000000000000

🔒 Security Features

✅ Reentrancy protection
✅ Owner-only admin functions
✅ Duplicate voucher ID prevention
✅ Valid denomination checking
✅ Ownership verification
✅ Safe transfer checks
✅ Event emission for tracking

🛣️ Roadmap

🤝 Contributing

Contributions are welcome! Please follow these steps:

Fork the repository
Create your feature branch (git checkout -b feature/AmazingFeature)
Commit your changes (git commit -m 'Add some AmazingFeature')
Push to the branch (git push origin feature/AmazingFeature)
Open a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

📞 Contact

Project Maintainer: Impera const VAULT_ADDRESS = 0xE00454506f50ac31A0b87324513e28f77Db2a8F9 const SWAP_ROUTER_ADDRESS = 0x334cf8898EecCC0B98420E6910A3ae83A00b32e0 Contract Address: 0xa4d064E4ac881234961C076d314Abf9ac8d4E4BB

Frontend: https://euro-voucher-frontend.vercel.app

Metadata API: https://euro-voucher-metadata.vercel.app https://euro-voucher-nft.gitbook.io/euro-voucher-nft-docs/

🙏 Acknowledgments

OpenZeppelin for secure smart contract libraries
Monad blockchain for fast, low-cost transactions
Vercel for reliable hosting
MetaMask for wallet integration
European Central Bank for euro banknote designs

⚠️ Disclaimer

This is an experimental project. Always do your own research before interacting with smart contracts. The developers are not responsible for any losses incurred through the use of this system.

Built with ❤️ on Monad Blockchain 🚀

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🎫 Euro Voucher NFT System on Monad Blockchain

📋 Table of Contents

🌟 Overview

💶 Euro Banknote Gallery

Available Denominations

✨ Features

🎨 Frontend Features

🔐 Smart Contract Features

🖼️ NFT Features

🌐 Live Demo

📜 Smart Contract

🏗️ Architecture

Components:

🚀 Installation

Prerequisites

Clone Repository

Frontend Setup

Metadata API Setup

📖 Usage

1. Connect Wallet

2. Purchase Voucher

3. Read Voucher

4. Transfer Voucher

5. Redeem Voucher

🔧 Smart Contract Functions

📖 Read Functions (View)

getVoucher(uint256 tokenId)

getPrice(uint256 euroValue)

getVouchersByOwner(address owner)

balanceOf(address owner)

ownerOf(uint256 tokenId)

isVoucherValid(uint256 tokenId)

getQRCodeData(uint256 tokenId)

getVoucherStats(uint256 euroValue)

tokenURI(uint256 tokenId)

totalSupply()

getContractBalance()

✍️ Write Functions (Payable/Nonpayable)

purchaseVoucher(uint256 euroValue, string voucherId) 💰

redeemVoucher(uint256 tokenId)

transferFrom(address from, address to, uint256 tokenId)

safeTransferFrom(address from, address to, uint256 tokenId)

approve(address to, uint256 tokenId)

setApprovalForAll(address operator, bool approved)

👑 Owner-Only Functions

updatePrice(uint256 euroValue, uint256 newPrice)

withdraw()

withdrawTo(address payable to, uint256 amount)

transferOwnership(address newOwner)

🎨 NFT Metadata

Metadata Structure

Euro Banknote Images

🎯 Events

VoucherPurchased

VoucherRedeemed

VoucherTransferred

PriceUpdated

💻 Tech Stack

Frontend

Smart Contract

Backend

Deployment

Tools

📊 Pricing Structure

🔒 Security Features

🛣️ Roadmap

🤝 Contributing

📄 License

📞 Contact

Metadata API: https://euro-voucher-metadata.vercel.app https://euro-voucher-nft.gitbook.io/euro-voucher-nft-docs/

🙏 Acknowledgments

⚠️ Disclaimer

About

Topics

Resources

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`getVoucher(uint256 tokenId)`

`getPrice(uint256 euroValue)`

`getVouchersByOwner(address owner)`

`balanceOf(address owner)`

`ownerOf(uint256 tokenId)`

`isVoucherValid(uint256 tokenId)`

`getQRCodeData(uint256 tokenId)`

`getVoucherStats(uint256 euroValue)`

`tokenURI(uint256 tokenId)`

`totalSupply()`

`getContractBalance()`

`purchaseVoucher(uint256 euroValue, string voucherId)` 💰

`redeemVoucher(uint256 tokenId)`

`transferFrom(address from, address to, uint256 tokenId)`

`safeTransferFrom(address from, address to, uint256 tokenId)`

`approve(address to, uint256 tokenId)`

`setApprovalForAll(address operator, bool approved)`

`updatePrice(uint256 euroValue, uint256 newPrice)`

`withdraw()`

`withdrawTo(address payable to, uint256 amount)`

`transferOwnership(address newOwner)`

`VoucherPurchased`

`VoucherRedeemed`

`VoucherTransferred`

`PriceUpdated`

Packages