💸 ExpenseAI - AI Expense & Micro-Savings Manager

A Next.js application that combines AI-powered expense categorization with blockchain-based micro-savings on U2U.

✨ Features

• AI Expense Categorization: Uses Google Gemini AI to automatically categorize transactions

• Frontend Wallet Integration: Connect MetaMask or other Web3 wallets directly in the browser

• Micro-Savings: Automatically calculate and save round-ups to a U2U smart contract

• Real-time Balance Tracking: Monitor your vault balance in real-time

🔧 Configuration

Environment Variables

• GEMINI_API_KEY: Your Google Gemini AI API key

• VAULT_ADDRESS: The deployed Vault smart contract address

• NEXT_PUBLIC_U2U_RPC: U2U RPC endpoint (defaults to testnet)

Smart Contract

The application uses a simple Vault contract with the following functions:

• deposit(): Accept U2U tokens

• withdraw(amount): Withdraw specified amount

• getBalance(user): Get user's balance

📱 Usage

1. Connect Wallet: Click "Connect Wallet" to connect your MetaMask or Web3 wallet

2. Enter Transactions: Paste JSON transaction data in the textarea

3. Categorize: Click "Categorize Expenses" to get AI-powered categorization

4. Save Round-ups: Click "Save Round-Ups" to automatically save spare change to your vault

Transaction Format

[  {"desc": "Uber Ride", "amount": 347, "date": "2024-01-15"},  {"desc": "Electricity Bill", "amount": 1547, "date": "2024-01-20"},  {"desc": "Grocery Shopping", "amount": 823, "date": "2024-01-18"},  {"desc": "Netflix Subscription", "amount": 499, "date": "2024-01-01"},  {"desc": "Restaurant Dinner", "amount": 1247, "date": "2024-01-16"}]

💡 Pro Tip: Use amounts that don't end in "00" to create round-ups for testing:

• ₹347 → saves ₹53 (rounds up to ₹400)

• ₹1547 → saves ₹53 (rounds up to ₹1600)

• ₹823 → saves ₹77 (rounds up to ₹900)

🏗️ Architecture

• Frontend: Next.js 15 with React 19 and TypeScript

• AI: Google Gemini 2.0 Flash for expense categorization

• Blockchain: U2U integration with ethers.js

• Styling: Tailwind CSS 4

🔒 Security

• No private keys stored on the server

• All blockchain transactions signed by user's wallet

• Environment variables properly configured for public/private access

• Input validation and error handling throughout

🧪 Testing

The application is configured for U2U Nebulas testnet by default. To use mainnet:

1. Update NEXT_PUBLIC_U2U_RPC to mainnet endpoint

2. Update the chain ID in lib/wallet.ts

3. Ensure you have mainnet U2U tokens