create-fastapi-rest-api

When to Use

When you need to build a modern, high-performance REST API in Python with automatic documentation, data validation, and type hints.

Prerequisites

• Python 3.8 or higher installed
• pip package manager
• Basic understanding of Python and HTTP concepts

Procedure

1. Create project directory: mkdir fastapi-project && cd fastapi-project

2. Create virtual environment: python -m venv venv

3. Activate virtual environment: source venv/bin/activate (Linux/Mac) or venv\Scripts\activate (Windows)

4. Install FastAPI and Uvicorn: pip install "fastapi[all]" uvicorn

5. Create main.py file: touch main.py

6. Add basic API code to main.py: from fastapi import FastAPI from pydantic import BaseModel

   app = FastAPI()

   class Item(BaseModel): name: str price: float

   @app.get("/") def read_root(): return {"Hello": "World"}

   @app.get("/items/{item_id}") def read_item(item_id: int, q: str = None): return {"item_id": item_id, "q": q}

   @app.post("/items/") def create_item(item: Item): return item

7. Run the development server: uvicorn main:app --reload

8. Access API documentation at: http://127.0.0.1:8000/docs

Verification

• Server starts without errors and shows "Uvicorn running on http://127.0.0.1:8000"
• Browser shows "Hello World" at http://127.0.0.1:8000
• Interactive API docs load at http://127.0.0.1:8000/docs
• Test endpoints return expected JSON responses

Pitfalls

• Virtual environment not activated leading to global package installation
• Port 8000 already in use (use --port 8001 flag)
• Missing type hints break automatic validation
• Forgetting --reload flag requires manual server restarts during development

Sources

• https://fastapi.tiangolo.com/
• https://github.com/fastapi
• https://realpython.com/get-started-with-fastapi/
• https://www.youtube.com/watch?v=7AMjmCTumuo
• https://en.wikipedia.org/wiki/FastAPI