DecentraArt NFT Marketplace - Smart Contracts

A decentralized NFT marketplace built on Ethereum with creator royalties and secondary sales support.

Features

• ERC-721 NFT Standard - Full compatibility with all NFT platforms
• Creator Royalties - Automatic royalty payments on secondary sales (up to 10%)
• Marketplace Functions - List, unlist, buy, and make offers on NFTs
• Secure - Built with OpenZeppelin contracts and ReentrancyGuard
• Gas Optimized - Efficient smart contract design
• 2.5% Marketplace Fee - Sustainable platform economics

Technology Stack

• Solidity ^0.8.20
• Hardhat (Development Framework)
• OpenZeppelin Contracts
• Ethers.js
• Mocha & Chai (Testing)

Smart Contract Functions

Core Functions

• mintNFT(tokenURI, royalty) - Create new NFT with royalty percentage
• listNFT(tokenId, price) - List NFT for sale
• unlistNFT(tokenId) - Remove NFT from marketplace
• buyNFT(tokenId) - Purchase listed NFT
• makeOffer(tokenId) - Make offer on any NFT
• acceptOffer(tokenId, offerIndex) - Accept an offer
• cancelOffer(tokenId, offerIndex) - Cancel your offer

View Functions

• getTokensByOwner(address) - Get all tokens owned by address
• getListedNFTs() - Get all listed NFTs in marketplace
• getTotalNFTs() - Get total minted NFTs
• getCreator(tokenId) - Get original creator
• getRoyalty(tokenId) - Get royalty percentage

Deployed Contracts

Sepolia Testnet

• Contract Address: 0xfFd322FBe14c824b3E8f25e69a68156bd4c4059C
• Network: Sepolia (Chain ID: 11155111)
• Explorer: View on Etherscan

Setup & Installation

Prerequisites

• Node.js v16+
• npm or yarn
• MetaMask wallet

Installation

# Clone the repository
git clone <your-repo-url>
cd nft-project-clean

# Install dependencies
npm install

# Create .env file
cp .env.example .env
# Add your PRIVATE_KEY and SEPOLIA_RPC_URL
Environment Variables
Create a .env file:
envPRIVATE_KEY=your_private_key_here
SEPOLIA_RPC_URL=https://eth-sepolia.g.alchemy.com/v2/YOUR_API_KEY
Never commit your .env file or expose private keys!
Testing
bash# Run all tests
npx hardhat test

# Run tests with gas reporting
REPORT_GAS=true npx hardhat test

# Run tests with coverage
npx hardhat coverage
Deployment
Deploy to Sepolia Testnet
bashnpx hardhat run scripts/deploy.js --network sepolia
Verify Contract (Optional)
bashnpx hardhat verify --network sepolia DEPLOYED_CONTRACT_ADDRESS
Project Structure
nft-project-clean/
├── contracts/
│   └── DecentraArt.sol          # Main NFT marketplace contract
├── scripts/
│   └── deploy.js                # Deployment script
├── test/
│   └── DecentraArt.test.js      # Test suite
├── hardhat.config.js            # Hardhat configuration
└── README.md
Security

Audited OpenZeppelin contracts
ReentrancyGuard protection
Ownership controls
Comprehensive test coverage

Gas Optimization
The contract is optimized for gas efficiency:

Minimal storage operations
Efficient loops
Batch operations where possible

License
MIT License
Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
Support
For questions and support, please open an issue in the GitHub repository.
Disclaimer
This is a testnet deployment for educational and demonstration purposes. Use at your own risk.