Uvicorn on AI VOID

Launch Your First FastAPI App: Hello World & Beyond

Sat, 25 Oct 2025 00:00:00 +0000

Launch Your First FastAPI App: Hello World & Beyond

What You’ll Learn

In this foundational chapter, you’ll take your very first steps into the world of FastAPI. By the end, you will be able to:

Set up a clean Python development environment using virtual environments.
Install FastAPI and Uvicorn, the server that runs your FastAPI applications.
Create your first “Hello World” FastAPI application.
Run your FastAPI application locally and access it from your web browser.
Understand the basics of FastAPI path operations and how to define simple GET request endpoints.
Return various basic responses, including strings and JSON objects.

Core Concepts

Welcome to building web applications with FastAPI! We’re going to start from scratch, ensuring you have a solid foundation.

Build a REST API with FastAPI

Tue, 26 May 2026 00:00:00 +0000

What you’ll build: A functional REST API using FastAPI, demonstrating setup, route definition, data validation, dependency injection, and testing. Time needed: ~75 minutes Prerequisites: Python 3.8 or newer, Basic understanding of Python, Familiarity with REST API concepts Version used: 0.115.6

FastAPI is a modern, fast (high-performance) web framework for building APIs with Python 3.8+ based on standard Python type hints. It’s designed to be easy to use, highly performant, and automatically generate interactive API documentation. In this tutorial, we’ll walk through building a complete, yet simple, REST API from scratch, covering the core features that make FastAPI a joy to work with.

Chapter 1: Initial Project Setup and Virtual Environment

Wed, 20 Aug 2025 00:00:00 +0000

The first step in any robust software project is to set up a clean and isolated development environment. This chapter will guide you through creating a new project directory and establishing a Python virtual environment to manage dependencies effectively.

Purpose of this Chapter

By the end of this chapter, you will have:

A dedicated project folder for your chat application.
A Python virtual environment configured to keep project dependencies separate from your system-wide Python installation.
Installed FastAPI and Uvicorn, the core components of our application.

Concepts Explained: Virtual Environments

A virtual environment is a self-contained directory tree that contains a Python installation for a particular version of Python, plus a number of additional packages.

Chapter 10: Securing WebSocket Communication

Wed, 20 Aug 2025 00:00:00 +0000

So far, our chat application uses JWT for HTTP authentication and passes the token as a query parameter for WebSockets. While this identifies the user, the actual WebSocket data transfer is currently unencrypted (WS://). For production, all traffic, especially sensitive chat messages, must be encrypted using WSS (WebSocket Secure), which relies on TLS/SSL certificates. This chapter focuses on enabling WSS and reinforcing WebSocket authentication.

Purpose of this Chapter

By the end of this chapter, you will:

Chapter 2: Your First FastAPI Endpoint and Project Structure

Wed, 20 Aug 2025 00:00:00 +0000

With your development environment ready, it’s time to write some code! This chapter focuses on creating a minimal FastAPI application, understanding its basic components, and establishing a sensible project structure.

Purpose of this Chapter

By the end of this chapter, you will be able to:

Write a simple “Hello, World!” FastAPI application.
Run the FastAPI application using Uvicorn.
Understand basic FastAPI routing.
Create a foundational project directory structure.

Concepts Explained: FastAPI Basics

FastAPI is a modern, fast (high-performance) web framework for building APIs with Python 3.8+ based on standard Python type hints. It offers: