FastAPI E-commerce API

A beginner-friendly e-commerce API built with FastAPI, featuring user management, product catalog, shopping cart, and order processing.

📁 Project Structure

ecommerce-api/
│
├── app/
│   ├── __init__.py
│   ├── database.py          # Database configuration
│   ├── models.py            # SQLAlchemy models
│   ├── schemas.py           # Pydantic schemas
│   └── routers/
│       ├── __init__.py
│       ├── users.py         # User endpoints
│       ├── products.py      # Product endpoints
│       ├── cart.py          # Cart endpoints
│       └── orders.py        # Order endpoints
│
├── main.py                  # Application entry point
├── requirements.txt         # Python dependencies
└── README.md               # This file

🚀 Setup Instructions

1. Create Project Directory

mkdir ecommerce-api
cd ecommerce-api

2. Create Virtual Environment

python -m venv venv

# Activate on Windows
venv\Scripts\activate

# Activate on Mac/Linux
source venv/bin/activate

3. Install Dependencies

pip install -r requirements.txt

4. Create Folder Structure

mkdir app
mkdir app/routers
touch app/__init__.py
touch app/routers/__init__.py

5. Run the Application

uvicorn main:app --reload

The API will be available at: http://127.0.0.1:8000

📚 API Documentation

Once running, visit:

• Swagger UI: http://127.0.0.1:8000/docs
• ReDoc: http://127.0.0.1:8000/redoc

🔑 API Endpoints

Users

• POST /api/v1/users - Register a new user
• GET /api/v1/users - Get all users
• GET /api/v1/users/{user_id} - Get user by ID

Products

• POST /api/v1/products - Create a product
• GET /api/v1/products - Get all products (with optional category filter)
• GET /api/v1/products/{product_id} - Get product by ID
• PUT /api/v1/products/{product_id} - Update a product
• DELETE /api/v1/products/{product_id} - Delete a product

Cart

• POST /api/v1/users/{user_id}/cart - Add item to cart
• GET /api/v1/users/{user_id}/cart - Get user's cart
• PUT /api/v1/users/{user_id}/cart/{cart_item_id} - Update cart item quantity
• DELETE /api/v1/users/{user_id}/cart/{cart_item_id} - Remove item from cart
• DELETE /api/v1/users/{user_id}/cart - Clear entire cart

Orders

• POST /api/v1/users/{user_id}/orders - Create order from cart
• GET /api/v1/users/{user_id}/orders - Get user's orders
• GET /api/v1/orders/{order_id} - Get order by ID
• PUT /api/v1/orders/{order_id}/status - Update order status

💡 Example Usage

1. Register a User

curl -X POST "http://127.0.0.1:8000/api/v1/users" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com",
    "username": "johndoe",
    "full_name": "John Doe",
    "password": "securepassword123"
  }'

2. Create a Product

curl -X POST "http://127.0.0.1:8000/api/v1/products" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Laptop",
    "description": "High-performance laptop",
    "price": 999.99,
    "stock": 50,
    "category": "Electronics"
  }'

3. Add to Cart

curl -X POST "http://127.0.0.1:8000/api/v1/users/1/cart" \
  -H "Content-Type: application/json" \
  -d '{
    "product_id": 1,
    "quantity": 2
  }'

4. Create Order

curl -X POST "http://127.0.0.1:8000/api/v1/users/1/orders"

🎓 Learning Points

This API demonstrates:

1. FastAPI Basics: Routes, dependencies, and request/response models
2. Database Operations: SQLAlchemy ORM with SQLite
3. Data Validation: Pydantic schemas for request/response validation
4. REST API Design: Proper HTTP methods and status codes
5. Relationships: One-to-many and many-to-many database relationships
6. Business Logic: Cart management, order processing, stock tracking
7. Security: Password hashing with bcrypt

🔧 Customization

Change Database

To use PostgreSQL instead of SQLite, modify app/database.py:

SQLALCHEMY_DATABASE_URL = "postgresql://user:password@localhost/dbname"
engine = create_engine(SQLALCHEMY_DATABASE_URL)

Add Authentication

Consider adding JWT authentication with python-jose and python-jose[cryptography].

📝 Next Steps

• Add authentication with JWT tokens
• Implement pagination for list endpoints
• Add search functionality for products
• Create product reviews and ratings
• Add payment integration
• Implement email notifications
• Add API rate limiting
• Create admin dashboard

🐛 Troubleshooting

Database not created?

• Delete ecommerce.db if it exists and restart the app

Import errors?

• Make sure all __init__.py files exist
• Check that you're in the virtual environment

Port already in use?

• Change port: uvicorn main:app --reload --port 8001# decentralized-app

decentralized-app

E-commerce-API

E-commerce-API

E-commerce-API

E-commerce-API