Small Business Inventory Management System

A comprehensive FastAPI-based inventory management system designed for small businesses to track products, manage suppliers, monitor stock levels, and handle inventory transactions.

Features

• Product Management: Add, update, and track inventory items with detailed information
• Category Management: Organize products into categories for better organization
• Supplier Management: Maintain supplier information and relationships
• Stock Tracking: Real-time stock level monitoring with low stock alerts
• Transaction History: Complete audit trail of all stock movements
• Authentication: Secure JWT-based authentication system
• Search & Filtering: Powerful search capabilities across inventory items
• RESTful API: Clean, well-documented API endpoints

Technology Stack

• Framework: FastAPI
• Database: SQLite with SQLAlchemy ORM
• Authentication: JWT tokens with PassLib for password hashing
• Migration: Alembic for database migrations
• Validation: Pydantic for data validation
• Documentation: Auto-generated OpenAPI/Swagger documentation

Installation

1. Install dependencies:

pip install -r requirements.txt

2. Run database migrations:

alembic upgrade head

3. Start the application:

uvicorn main:app --host 0.0.0.0 --port 8000 --reload

Environment Variables

The following environment variables can be set to configure the application:

• SECRET_KEY: JWT secret key (default: "your-secret-key-change-this-in-production")
• FIRST_SUPERUSER_EMAIL: Admin user email (default: "admin@inventory.com")
• FIRST_SUPERUSER_PASSWORD: Admin user password (default: "admin123")

Important: Change the default SECRET_KEY and admin credentials in production!

API Documentation

Once the application is running, you can access:

• Interactive API Documentation: http://localhost:8000/docs
• Alternative Documentation: http://localhost:8000/redoc
• OpenAPI Schema: http://localhost:8000/openapi.json

API Endpoints

Authentication

• POST /auth/login - User login

Categories

• GET /categories/ - List all categories
• POST /categories/ - Create new category
• GET /categories/{id} - Get category by ID
• PUT /categories/{id} - Update category
• DELETE /categories/{id} - Delete category

Suppliers

• GET /suppliers/ - List all suppliers
• POST /suppliers/ - Create new supplier
• GET /suppliers/{id} - Get supplier by ID
• PUT /suppliers/{id} - Update supplier
• DELETE /suppliers/{id} - Delete supplier

Items

• GET /items/ - List all items
• POST /items/ - Create new item
• GET /items/{id} - Get item by ID
• PUT /items/{id} - Update item
• DELETE /items/{id} - Delete item
• GET /items/search?query={query} - Search items
• GET /items/low-stock - Get items with low stock
• GET /items/active - Get active items only

Stock Transactions

• GET /stock-transactions/ - List all transactions
• POST /stock-transactions/ - Create new transaction (updates stock automatically)
• GET /stock-transactions/{id} - Get transaction by ID
• GET /stock-transactions/item/{item_id} - Get transactions for specific item
• GET /stock-transactions/type/{type} - Get transactions by type (in/out/adjustment)

System

• GET / - API information and links
• GET /health - Health check endpoint

Database Schema

The system uses the following main entities:

• Users: System users with authentication
• Categories: Product categories for organization
• Suppliers: Supplier information and contacts
• Items: Inventory items with pricing and stock information
• StockTransactions: Record of all stock movements

Usage Examples

1. Login

curl -X POST "http://localhost:8000/auth/login" \
  -H "Content-Type: application/json" \
  -d '{"email": "admin@inventory.com", "password": "admin123"}'

2. Create a Category

curl -X POST "http://localhost:8000/categories/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name": "Electronics", "description": "Electronic devices and components"}'

3. Add an Item

curl -X POST "http://localhost:8000/items/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Laptop Computer",
    "description": "High-performance laptop",
    "sku": "LAP001",
    "unit_price": 999.99,
    "cost_price": 750.00,
    "quantity_in_stock": 10,
    "minimum_stock_level": 2,
    "reorder_point": 5,
    "category_id": 1
  }'

4. Record Stock Transaction

curl -X POST "http://localhost:8000/stock-transactions/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "item_id": 1,
    "transaction_type": "out",
    "quantity": 2,
    "reference_number": "SALE001",
    "notes": "Sale to customer"
  }'

Development

Running with Auto-reload

uvicorn main:app --reload

Code Formatting

The project uses Ruff for linting and formatting:

ruff check .
ruff format .

Database Migrations

Create a new migration:

alembic revision --autogenerate -m "Description of changes"

Apply migrations:

alembic upgrade head

Production Deployment

1. Set secure environment variables
2. Use a production WSGI server like Gunicorn
3. Configure proper SSL/TLS certificates
4. Set up database backups
5. Configure logging and monitoring

License

This project is open source and available under the MIT License.