A Chrome extension that intercepts online shopping checkouts and gives you real-time financial coaching — powered by Google Gemini and MongoDB.

When you go to checkout on a supported retail site, CartCoach automatically detects the product and price, then shows a popup with:

• Risk assessment — how much of your monthly budget this purchase uses, how many days it delays your savings goal, and what the money could grow to if invested instead
• Smarter options — skip it, wishlist it, or find cheaper alternatives via live eBay listings
• Savings tracking — if you skip, it asks whether you're putting the money into savings or spending elsewhere, and logs it accordingly

Everything is tracked in a full dashboard with history, wishlist, ledger, and an AI chatbot powered by Gemini.

cartcoach/
├── backend/          # FastAPI server
│   ├── api/routers/  # analyze, users, wishlist, ledger, insights
│   ├── db/           # MongoDB connection (Motor)
│   ├── logic/        # finance engine, recommendation, eBay scraper
│   └── models/       # Pydantic schemas
├── extension/        # Chrome extension
│   └── src/
│       ├── components/   # InterventionModal, RiskWarning, LedgerTable, etc.
│       ├── dashboard/    # Full dashboard UI
│       ├── popup/        # Extension popup
│       ├── content/      # DOM scraper content script
│       └── background/   # Service worker
└── shared/           # Shared TypeScript types + constants

• Node.js 18+
• Python 3.11+
• MongoDB running locally (mongod) or a MongoDB Atlas connection string
• Google Gemini API key

cd cartcoach/backend
pip install -r requirements.txt
playwright install chromium

Create a .env file in cartcoach/backend/:

GEMINI_API_KEY=your_key_here
MONGODB_URL=mongodb://localhost:27017
MONGODB_DB=cartcoach

Start the server:

uvicorn main:app --reload --port 8000

cd cartcoach/extension
npm install
npm run build

Then in Chrome:

1. Go to chrome://extensions
2. Enable Developer mode
3. Click Load unpacked and select the dist/ folder

Amazon, Target, Walmart, Best Buy, Sephora, Etsy

• Intervention popup — modal injected via iframe on checkout pages without breaking host site CSS
• Risk scoring — low / medium / high based on budget impact and goal delay
• Finance engine — real-time budget impact, S&P 500 compound projections, savings goal delay in days
• Gemini chatbot — answers financial questions using your live budget and savings context
• Alternatives — Playwright scrapes eBay for cheaper live listings
• Dashboard — overview, history, wishlist, ledger, and insights tabs
• Skip follow-up — tracks whether skipped money goes to savings or is spent elsewhere