Expense Tracker Ultimate – Backend + PostgreSQL

This project is now split into:

• Static frontend: index-ultimate.html, styles-ultimate.css, script-enhanced.js
• TypeScript backend: backend/src/server.ts (Node + Express + PostgreSQL)

1. Prerequisites

• Node.js (v18+ recommended)
• PostgreSQL running locally or in the cloud

2. PostgreSQL setup

Create a database and a user (example):

CREATE DATABASE expense_tracker;
CREATE USER expense_user WITH PASSWORD 'your-strong-password';
GRANT ALL PRIVILEGES ON DATABASE expense_tracker TO expense_user;

Then create a .env file in the project root (same folder as package.json):

DATABASE_URL=postgres://expense_user:your-strong-password@localhost:5432/expense_tracker
PORT=4000

The backend will automatically create the expenses table on first start.

3. Install dependencies

From the project root (expense-tracker):

npm install

4. Run the backend (TypeScript)

For development (auto‑reload with nodemon + ts-node):

Npm DEV run

The API and static frontend will be served from:

• http://localhost:4000 (index page)
• http://localhost:4000/api/expenses (REST API)

5. Build and run in JS (optional)

To build the backend to plain JavaScript and run it:

npm run build:backend
npm start

6. Main API endpoints

• GET /api/health – quick health check
• GET /api/expenses – list expenses (supports category, startDate, endDate query params)
• POST /api/expenses – create a new expense
  • body: { description, amount, category, currency, date }
• GET /api/expenses/stats – totals, average, highest, count
• GET /api/expenses/breakdown – totals per category

The frontend (script-enhanced.js) calls these endpoints to:

• Load and filter the expense list
• Show total/average/highest stats
• Render the category breakdown cards
• Add new expenses via the form

Expense-Tracker