☕ Coffee Change

An automated micro-investment app that tracks Solana wallet transactions and rounds up each outgoing transaction to the nearest USD value. The rounded-up difference is accumulated off-chain and later transferred on-chain to a pooled investment contract.

🎯 Features

• Wallet Integration: Connect with Phantom, Solflare, or Backpack wallets
• Transaction Tracking: Real-time monitoring of Solana wallet transactions
• Round-up Calculation: Automatic calculation of round-up amounts
• Investment Pool: Transfer round-ups to a pooled investment contract
• Portfolio Tracking: View your investment position and performance

🚀 Getting Started

Prerequisites

• Node.js 18+
• npm or yarn
• A Solana wallet (Phantom, Solflare, or Backpack)

Installation

1. Clone the repository:

git clone <repository-url>
cd coffee-change

2. Install dependencies:

npm install

3. Start the development server:

npm run dev

4. Open http://localhost:3000 in your browser

🏗️ Project Structure

src/
├── app/
│   ├── api/                    # API endpoints
│   │   ├── transactions/scan/ # Transaction scanning
│   │   ├── prices/            # Price oracle data
│   │   └── pool/position/     # Pool position data
│   ├── globals.css            # Global styles with coffee theme
│   ├── layout.tsx             # Root layout with Solana provider
│   └── page.tsx               # Main app entry point
├── components/
│   ├── ui/                    # Reusable UI components
│   ├── app-navigation.tsx     # Main navigation component
│   ├── dashboard.tsx        # Dashboard with wallet info
│   ├── roundup-review.tsx     # Round-up review and transfer
│   ├── investment-position.tsx # Investment portfolio view
│   ├── solana-provider.tsx    # Solana wallet context
│   └── wallet-connect-button.tsx # Wallet connection UI
└── lib/
    └── utils.ts               # Utility functions

🎨 Design System

The app uses a coffee-themed design system with:

• Primary Colors:

  • Dark Coffee Bean (#2D2016) - Primary text and backgrounds
  • Mocha Brown (#735557) - Buttons and accents
  • Creamy Foam (#D9D9D9) - Card backgrounds and surfaces

• Typography: Clean, modern sans-serif fonts (Inter, Sora, Roboto)

• Layout: Card-based design with rounded corners and subtle shadows

🔧 Development

Available Scripts

• npm run dev - Start development server
• npm run build - Build for production
• npm run start - Start production server
• npm run lint - Run ESLint

Key Components

1. Dashboard: Main screen showing wallet info, transaction tracking, and round-up balance
2. Round-up Review: Screen for reviewing and confirming round-up transfers
3. Investment Position: Portfolio view showing user's position in the investment pool

API Endpoints

• GET /api/transactions/scan - Get latest transaction scan results
• POST /api/transactions/scan - Trigger new transaction scan
• GET /api/prices - Get current SOL/USD and USDC/USD prices
• GET /api/pool/position?wallet=<address> - Get user's pool position

🌐 Network

Currently configured for Solana Devnet for development and testing.

📱 Wallet Support

• Phantom
• Solflare
• Backpack
• Any wallet supporting the Wallet Standard

🚧 Development Status

This is a development version with mock data. In production, you would need to:

1. Implement real transaction scanning
2. Connect to actual price oracles
3. Deploy smart contracts for the investment pool
4. Add real wallet balance fetching
5. Implement actual Solana transactions

📄 License

This project is for development purposes.