Getting Started with FastAPI and Python

In software development, we often look for frameworks that make building APIs faster, cleaner, and more efficient. That’s exactly what FastAPI offers. It’s a modern web framework built with Python, designed for creating high-performance APIs with minimal effort.

I started learning FastAPI because I wanted to understand how developers build powerful yet simple backends. What stood out to me immediately was how quick it is to set up and how much it takes care of for you behind the scenes — especially things like validation and documentation.

What is FastAPI?

FastAPI is a Python framework for building APIs that are fast, easy to use, and well-documented by default. It’s built on top of Starlette (for the web parts) and Pydantic (for data validation).

One of its biggest strengths is automatic documentation. With just a few lines of code, FastAPI generates clean, interactive API docs using Swagger UI and ReDoc — you don’t have to set up anything extra.

Why Developers Love FastAPI

• High Performance – It’s one of the fastest Python frameworks, almost as fast as Node.js or Go.

• Type Hints Support – You can define request and response data using Python type hints, and FastAPI handles validation automatically.

• Auto Documentation – OpenAPI and Swagger docs are generated instantly.

• Easy Integration – Works perfectly with SQL databases, authentication systems, and background tasks.

Building Your First FastAPI App

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "Welcome to my first FastAPI app!"}

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

To run the app, use:

uvicorn main:app --reload

Then open the browser and go to:

http://127.0.0.1:8000

You will See an Api Running instantly, visit :

http://127.0.0.1:8000/docs

Where FastAPI Fits Best

• RESTful APIs

• Microservices

• Machine Learning model deployment

• Backend for web and mobile apps

FastAPI is asynchronous (built on async and await), it can handle multiple requests at the same time efficiently — perfect for scalable applications.

Conclusion

FastAPI is one of those frameworks that truly respects your time as a developer. It’s fast, elegant, and makes backend development feel effortless. Whether you’re building a small project or a full production system, it gives you the flexibility and performance you need — all in pure Python.

If you’re new to API development or looking for a cleaner alternative to Flask or Django REST Framework, FastAPI is definitely worth exploring.