🏪 Inventory Management System

A full-stack inventory management system built for a clothing store. It handles product management, stock tracking, sales, and reporting — with role-based access control for owners and cashiers.

Note: The backend was built independently as a learning project. The frontend was built with the assistance of AI (Claude by Anthropic).

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✨ Features

• 🔐 Authentication — JWT-based auth with refresh token rotation and httpOnly cookies
• 👥 User Management — Owner can create and manage cashier accounts
• 📁 Categories — Organize products into categories
• 👕 Products — Full product management with size variants (S/M/L/XL)
• 📦 Inventory — Track stock movements (in, out, adjustments) with full audit trail
• 🧾 Sales — Cashier POS with automatic stock deduction
• 📊 Reports — Revenue, profit, top products, low stock alerts, and cashier performance

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🛠️ Tech Stack

Backend

Technology	Purpose
Node.js + TypeScript	Runtime & language
Express 5	Web framework
Prisma 7	ORM
PostgreSQL	Database
Zod 4	Validation
JWT + bcrypt	Auth & password hashing
ES Modules	Module system

Frontend

Technology	Purpose
React + TypeScript	UI framework
Vite	Build tool
Tailwind CSS	Styling
React Router	Navigation
Axios	HTTP client

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🗂️ Project Structure

store-system/
├── backend/
│   └── src/
│       ├── modules/
│       │   ├── auth/
│       │   ├── user/
│       │   ├── category/
│       │   ├── product/
│       │   ├── inventory/
│       │   ├── sales/
│       │   └── reports/
│       ├── common/
│       │   ├── middlewares/
│       │   ├── utils/
│       │   └── errors/
│       ├── config/
│       └── routes/
│
└── frontend/
    └── src/
        ├── api/
        ├── components/
        ├── pages/
        ├── hooks/
        ├── types/
        └── router/

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🗄️ Database Schema

Category → Product → ProductVariant → StockMovement
                                    → SaleItem → Sale → User (cashier)

Models: User, Category, Product, ProductVariant, Sale, SaleItem, StockMovement

Enums: Role (ADMIN, CASHIER), StockMovementType (IN, OUT, ADJUSTMENT)

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🚀 Getting Started

Prerequisites

• Node.js 18+
• PostgreSQL

Backend Setup

cd backend
npm install
cp .env.example .env

Fill in your .env:

DATABASE_URL="postgresql://postgres:password@localhost:5432/store_db"
PORT=8000
NODE_ENV=development
JWT_SECRET=your_jwt_secret
JWT_EXPIRES_IN=15m
REFRESH_TOKEN_EXPIRES_IN=7d

Run migrations and start:

npx prisma migrate dev
npm run dev

Frontend Setup

cd frontend
npm install
npm run dev

Frontend runs on http://localhost:5173 and proxies API requests to http://localhost:8000.

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🔑 First Time Setup

On first run, create the admin account via:

POST /api/v1/auth/bootstrap-register
{
  "name": "Store Owner",
  "email": "owner@example.com",
  "password": "yourpassword"
}

This endpoint is only available once — it locks automatically after the first ADMIN is created.

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📡 API Endpoints

Auth

Method	Endpoint	Description	Access
POST	/api/v1/auth/bootstrap-register	Create first admin	Public (once)
POST	/api/v1/auth/login	Login	Public
POST	/api/v1/auth/refresh	Refresh access token	Public
POST	/api/v1/auth/logout	Logout	Auth

Users

Method	Endpoint	Description	Access
POST	/api/v1/users	Create cashier	ADMIN
GET	/api/v1/users	Get all users	ADMIN
GET	/api/v1/users/:id	Get user by ID	ADMIN
PATCH	/api/v1/users/:id	Update user	ADMIN
DELETE	/api/v1/users/:id	Delete user	ADMIN
PATCH	/api/v1/users/me/change-password	Change own password	Auth
PATCH	/api/v1/users/:id/reset-password	Reset user password	ADMIN

Categories

Method	Endpoint	Description	Access
POST	/api/v1/categories	Create category	ADMIN
GET	/api/v1/categories	Get all categories	Auth
GET	/api/v1/categories/:id	Get category by ID	Auth
PATCH	/api/v1/categories/:id	Update category	ADMIN
DELETE	/api/v1/categories/:id	Delete category	ADMIN

Products

Method	Endpoint	Description	Access
POST	/api/v1/products	Create product with variants	ADMIN
GET	/api/v1/products	Get all products	Auth
GET	/api/v1/products/:id	Get product by ID	Auth
PATCH	/api/v1/products/:id	Update product	ADMIN
DELETE	/api/v1/products/:id	Delete product	ADMIN

Inventory

Method	Endpoint	Description	Access
POST	/api/v1/inventory/stock-in	Add stock	ADMIN
POST	/api/v1/inventory/stock-out	Remove stock	ADMIN
POST	/api/v1/inventory/adjust	Manual adjustment	ADMIN
GET	/api/v1/inventory/:variantId/history	Stock movement history	ADMIN

Sales

Method	Endpoint	Description	Access
POST	/api/v1/sales	Create sale	Auth
GET	/api/v1/sales	Get all sales	ADMIN
GET	/api/v1/sales/:id	Get sale by ID	ADMIN

Reports

Method	Endpoint	Description	Access
GET	/api/v1/reports/summary	Revenue & profit summary	ADMIN
GET	/api/v1/reports/top-products	Best selling products	ADMIN
GET	/api/v1/reports/low-stock	Low stock alerts	ADMIN
GET	/api/v1/reports/cashiers	Cashier performance	ADMIN

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🔒 Security Features

• Refresh token rotation on every refresh
• Refresh tokens hashed with SHA-256 before DB storage
• httpOnly cookies for refresh tokens
• Access tokens in memory only
• Password hashing with bcrypt
• Request rate limiting
• Input validation with Zod

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🤝 Acknowledgements

The frontend UI was built with the assistance of Claude (by Anthropic) as part of an AI-assisted development workflow. The backend was designed and implemented independently as a hands-on learning project in Node.js and TypeScript.