InvoiceLite Backend

A lightweight, production-ready REST API for an invoicing SaaS designed for micro and small businesses. Built with Node.js, Express, and MongoDB.

Features

• Authentication System: Secure user registration and login using JWT and bcrypt.
• Client Management: Full CRUD operations for managing clients.
• Invoice Tracking: Create, read, update, and delete invoices. Includes automatic subtotal, tax, and total calculations.
• Automated Status Logic: Invoices are automatically marked as "overdue" if their due date has passed and they remain unpaid.
• API Documentation: Interactive Swagger (OpenAPI 3.0) documentation available out of the box.

Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB with Mongoose ODM
• Authentication: JSON Web Tokens (JWT) & bcryptjs
• Documentation: swagger-jsdoc & swagger-ui-express

Project Structure

server/
├── controllers/    # API request handlers and business logic
├── models/         # Mongoose schema definitions
├── routes/         # Express endpoint definitions
├── middleware/     # Custom HTTP middleware (auth, error handler)
├── config/         # Environment and database config files
├── utils/          # Helper utilities (JWT generation)
├── docs/           # Swagger configuration
├── app.js          # Express app setup and middleware pipeline
└── server.js       # Application entry point and server startup

Getting Started

Prerequisites

• Node.js (v16+)
• MongoDB installed and running locally on the default port 27017 (or modify MONGODB_URI in .env).

Installation

1. Clone or download the repository, then navigate to the backend directory:

   cd Backend

2. Install the dependencies:

   npm install

Configuration

A .env.example file is provided. Create a new file named .env and configure your local environment variables:

PORT=5000
MONGODB_URI=mongodb://localhost:27017/invoicelite
JWT_SECRET=your_super_secret_jwt_key
JWT_EXPIRE=30d

Running the API

Start the development server with auto-reloading (nodemon):

npm run dev

Or start the server normally:

node server.js

The server will be available at http://localhost:5000.

Documentation

Interactive API documentation is generated automatically using Swagger. Once the server is running, you can explore the endpoints and test the API at:

http://localhost:5000/api/docs

License

ISC License