Want to learn how to combine React 19 and AI LLMs to build something handy?
We just published a course on the freeCodeCamp.org YouTube channel that will teach you to build an AI-powered Code Explainer App from scratch. Tapas Adhikary created this course.
Learn to design the app, configure an Express.js backend, set up a REST endpoint that talks to an LLM, and then integrate everything into a modern React 19 app (with Vite + TailwindCSS).
By the end you’ll have a working AI Code Explainer tool that takes any code snippet and returns clear, beginner-friendly explanations. Along the way, you’ll also learn about React 19’s new features like useActionState and Server Actions, plus best practices for API integration and error handling.
This course covers:
How to design and plan an AI project
Configuring Express.js for REST APIs
Connecting to an LLM for code explanation
Testing APIs with Postman
Building a modern frontend with React 19, Vite, and TailwindCSS
Using React 19’s useActionState + Server Actions in real projects
Handling API responses and formatting output
Watch the full course on the freeCodeCamp.org YouTube channel (1-hour watch).