How the Web and AI Apps Work: Request Path, HTTP & APIs (Python)

What really happens when you send a message to an AI chat app? In this first lesson of the course, you'll follow one message from your browser, through DNS and HTTP, to a backend server and an LLM API, and back again. Then you'll build a tiny chat server and client in Python, with nothing to install. Lesson 1 of Module 1 (Developer foundations) in the Data24Zone AI Full-Stack Developer course. Welcome! What you'll learn: The three parts of every AI app: frontend, backend and the model The request path: browser, DNS, server, LLM API and back HTTP methods, paths, headers, bodies and status codes How to watch requests in your browser's dev tools Python: a real chat server with http.server and a client with urllib Flowchart and step-by-step trace of the code Debug a real KeyError with a 4-step routine Chapters: 0:00 Intro 0:40 An everyday example 1:43 The request path 3:30 Speaking HTTP 5:23 Code it in Python 9:22 Debug it 10:30 Mistakes, quiz and your turn