CodeTrain / Learn
Every course, class by class
These are the curated courses, written by hand as a place to start. A course is a line, each class is a stop along it, and every class is a set of hands-on lessons where you type each small step yourself. You are not limited to them: ask CodeTrain for any topic and it builds the lesson on the spot, or point it at any public repository and it teaches you that codebase instead.
Curated courses
Learn to Code in Python
Start from zero and write real Python from your very first line.
Object-Oriented Python
Model real things with classes, and learn when OOP earns its keep.
JavaScript Fundamentals
The language that runs the web: values, arrays, and control flow.
JavaScript: Functions & Data
Functions are values: pass them around, return them, and capture state.
Command the Terminal: Linux & Bash
Stop fearing the shell. Move around, wire commands, automate the boring parts.
How LLMs Actually Work
From a single neuron to a working transformer, built from scratch in pure NumPy, in your browser.
The Backend Course · coming soon
The Web Course · coming soon
Data with Python · coming soon
How CodeTrain teaches this
No videos and no multiple-choice quiz at the end. Each lesson is a handful of small steps in a real editor. You type the code yourself, it runs, and the tutor reviews what you actually wrote. It will not hand you the answer, and the step doesn't advance until your code passes. What you get at the end is a record of which steps you wrote unaided, not a completion percentage.
These curated courses are the starting point, not the product
Everything in this catalog is a curated course we wrote by hand. They exist so there is something to start on. What CodeTrain actually does is build a lesson on demand: name any topic you want to understand and it writes one for you on the spot, or paste any public repository and it teaches you that codebase from the code that is really in it. You are not limited to the list below, and most people stop using it within a session or two.
Start here instead
Two guides, if you would rather understand the method or bring your own code than pick a course off the list.
How a Socratic coding tutor works
The rules the tutor runs under, quoted from the prompt, and what they do to a real step.
Learn any codebase in 30 minutes
Paste a public repo and learn it by writing in it. The path, step by step, and what it refuses to read.