🏪 ChainMart - Web3 Digital Goods Marketplace

A decentralized marketplace for buying and selling digital goods on the blockchain

📱 App Screenshots

🔍 Discovery Page Browse and filter products by categories

➕ Create Product Upload your digital goods to the blockchain

🚀 About ChainMart

ChainMart is a revolutionary Web3 digital marketplace that combines the power of blockchain technology with a user-friendly mobile experience. Built with Flutter for cross-platform compatibility and powered by Ethereum smart contracts, ChainMart enables users to:

• 🛍️ Buy & Sell Digital Goods - Trade NFTs, digital art, documents, and more
• 🔗 Blockchain Verification - Every transaction is recorded on the Ethereum blockchain
• 💰 Crypto Payments - Secure payments with ETH on Sepolia testnet
• 📱 Mobile-First Design - Native mobile experience on Android and iOS
• 🎨 Rich Media Support - Upload images, documents, audio, and video files
• 🏷️ Category Filtering - Organize products by Art, 3D, Crypto, Collections, and more

🛠️ Technology Stack

🎯 Frontend (Mobile App)

• Flutter 3.8+ - Cross-platform mobile development framework
• Dart - Programming language for Flutter
• Provider - State management solution
• Reown AppKit - Web3 wallet connectivity
• Flutter Staggered Grid View - Beautiful grid layouts
• URL Launcher - External link handling
• Image Picker - Camera and gallery access
• File Picker - Multi-format file selection
• Shared Preferences - Local data storage
• HTTP - API communication
• Random Avatar - User avatar generation

⛓️ Blockchain (Smart Contracts)

• Solidity 0.8.20 - Smart contract programming language
• Hardhat - Ethereum development environment
• Ethers.js v6 - Ethereum JavaScript library
• OpenZeppelin - Security-audited contract libraries
• Web3dart - Dart Ethereum integration
• Ethereum Sepolia Testnet - Test network for development

🗄️ Storage & Infrastructure

• IPFS (Pinata) - Decentralized file storage
• Alchemy - Ethereum node provider
• Etherscan API - Blockchain explorer integration

🧪 Testing & Development

• Hardhat Testing - Smart contract testing framework
• Chai - Assertion library for testing
• Flutter Test - Widget and integration testing
• Hardhat Gas Reporter - Gas usage analysis
• Solidity Coverage - Code coverage analysis

📋 Project Structure

ChainMart/
├── 📱 Mobile App (Flutter)
│   ├── lib/
│   │   ├── main.dart                    # App entry point
│   │   ├── models/
│   │   │   └── products_model.dart      # Product data model
│   │   ├── pages/
│   │   │   ├── splash_page.dart         # App splash screen
│   │   │   ├── discovery_page.dart      # Product browsing
│   │   │   ├── create_product_page.dart # Product creation
│   │   │   ├── products_details_page.dart # Product details
│   │   │   └── account_profile_page.dart  # User profile
│   │   ├── services/
│   │   │   └── contract_factory_services.dart # Blockchain integration
│   │   ├── widgets/
│   │   │   ├── custom_products_widget.dart    # Product cards
│   │   │   ├── purchase_success_dialog.dart   # Success dialogs
│   │   │   └── ...                            # Other UI components
│   │   └── utils/
│   │       └── constant.dart            # App constants
│   ├── assets/images/                   # App images and logos
│   ├── android/                         # Android-specific files
│   ├── ios/                            # iOS-specific files
│   └── pubspec.yaml                    # Flutter dependencies
│
├── ⛓️ Blockchain (Hardhat)
│   ├── contracts/
│   │   └── Kellzon.sol                 # Main marketplace contract
│   ├── scripts/
│   │   ├── deploy_contract.js          # Contract deployment
│   │   ├── Deploy.js                   # Deployment utilities
│   │   └── ...                         # Other scripts
│   ├── test/
│   │   └── Kellzon.test.js             # Smart contract tests
│   ├── hardhat.config.js               # Hardhat configuration
│   ├── package.json                    # Node.js dependencies
│   └── ...
│
└── 📄 Documentation
    ├── README.md                       # This file
    ├── coverage/                       # Test coverage reports
    └── artifacts/                      # Compiled contracts

🔧 Features

🛒 Marketplace Features

• Product Listing - Create and list digital products with rich metadata
• Category Management - Organize products by Art, 3D, Crypto, Collections
• Search & Filter - Find products by category and availability
• Product Details - Comprehensive product information and media
• Transaction History - View all purchases and sales
• Blockchain Explorer - Direct links to Etherscan transactions

💳 Web3 Integration

• Wallet Connection - Connect with MetaMask and other Web3 wallets
• Smart Contract Interaction - Direct blockchain communication
• Transaction Tracking - Real-time transaction status updates
• Gas Optimization - Efficient contract calls and state management
• Event Listening - React to blockchain events in real-time

📁 File Management

• Multi-Format Support - Images, documents, audio, video files
• IPFS Storage - Decentralized file storage and retrieval
• File Preview - Visual previews for different file types
• Batch Upload - Upload multiple files simultaneously
• File Validation - Size and format validation

🎨 User Interface

• Material Design - Modern, intuitive UI following Material guidelines
• Dark/Light Themes - Customizable appearance
• Responsive Layout - Optimized for all screen sizes
• Smooth Animations - Fluid transitions and interactions
• Loading States - Clear feedback during operations

🚀 Getting Started

Prerequisites

• Flutter SDK 3.8.0 or higher
• Dart SDK 2.19.0 or higher
• Node.js v16+ with npm/yarn
• Android Studio / VS Code with Flutter extensions
• MetaMask or other Web3 wallet

📱 Mobile App Setup

1. Clone the repository

   git clone https://github.com/your-username/chainmart.git
   cd chainmart

2. Install Flutter dependencies

   flutter pub get

3. Configure environment variables

   # Create .env file with your API keys
   PINATA_API_KEY=your_pinata_api_key
   PINATA_SECRET_API_KEY=your_pinata_secret
   ALCHEMY_API_URL=your_alchemy_sepolia_url

4. Run the app

   # For debug mode
   flutter run
   
   # For release mode
   flutter run --release

⛓️ Blockchain Setup

1. Install Node.js dependencies

   npm install
   # or
   yarn install

2. Configure Hardhat

   # Create .env file with your keys
   PRIVATE_KEY_METAMASK=your_private_key
   ALCHEMY_API_URL=your_alchemy_sepolia_url
   ETHERSCAN_API_KEY=your_etherscan_api_key

3. Compile contracts

   npx hardhat compile

4. Run tests

   npx hardhat test

5. Deploy to Sepolia

   npx hardhat run scripts/deploy_contract.js --network sepolia

🧪 Testing

Smart Contract Tests

# Run all tests
npx hardhat test

# Run with coverage
npx hardhat coverage

# Run gas reporter
npx hardhat test --reporter gas

Flutter Tests

# Run unit tests
flutter test

# Run integration tests
flutter test integration_test/

# Run with coverage
flutter test --coverage

📦 Build & Deployment

📱 Mobile App Build

Android:

# Debug APK
flutter build apk --debug

# Release APK  
flutter build apk --release

# App Bundle for Play Store
flutter build appbundle --release

iOS:

# iOS build
flutter build ios --release

# Create IPA for App Store
flutter build ipa --release

⛓️ Contract Deployment

Sepolia Testnet:

# Deploy contract
npx hardhat run scripts/deploy_contract.js --network sepolia

# Verify on Etherscan
npx hardhat verify --network sepolia DEPLOYED_CONTRACT_ADDRESS

🔐 Security Features

• Smart Contract Auditing - Comprehensive testing and security checks
• Access Control - Owner-only functions for sensitive operations
• Input Validation - Robust validation on all user inputs
• Transaction Verification - Multi-layer transaction validation
• Secure Storage - Encrypted local storage for sensitive data
• Network Security - HTTPS/WSS for all network communications

🤝 Contributing

We welcome contributions! Please see our Contributing Guidelines for details.

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

📄 License

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

👨‍💻 Developer

Ezequiel Silva

• 💼 LinkedIn: Kell Silva
• 🌟 Specializing in: Web3 Development, Mobile App Development, Blockchain Solutions
• 📧 Contact: Connect via LinkedIn for collaboration opportunities

🙏 Acknowledgments

• Flutter Team for the amazing cross-platform framework
• Ethereum Foundation for the blockchain infrastructure
• Hardhat Team for the excellent development tools
• OpenZeppelin for security-audited smart contracts
• Pinata for IPFS storage solutions
• Alchemy for reliable Ethereum node services

📈 Roadmap

• Multi-chain Support - Expand to Polygon, BSC, and other chains
• NFT Integration - Native NFT minting and trading
• Social Features - User profiles, reviews, and ratings
• Advanced Analytics - Market insights and sales analytics
• Mobile Wallet - Built-in wallet functionality
• DeFi Integration - Staking, lending, and yield farming
• Desktop App - Flutter desktop application
• Web Version - Progressive web app deployment

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Made with ❤️ by Ezequiel Silva

Empowering the future of decentralized commerce