Practice
The workbench
Three panes: the lesson, a real editor, and a real terminal. Write your solution, run the tests, and watch them go green without leaving the window.
Version 0.1.0
The macOS app is signed and notarized by Apple and opens like any other. The Windows installer is not code-signed yet, so SmartScreen may stop it the first time: choose More info, then Run anyway. It then installs like any app and shows up in Start and in Installed apps.
Or build it from source
pnpm install
pnpm content
pnpm dev:desktopWhat you need
Python 3.10 or newer, to run the exercise tests. Rust and a platform toolchain only if you are building the app yourself.
Nothing else. No API key, no virtual environment, no local model. The app checks your setup on first launch and tells you exactly what is missing rather than failing at the moment you press Run.
How exercises open
On a scaffold: function signatures and docstrings with empty bodies. A complete reference solution ships beside it, and the app will not show it unless you ask.
Reading a working solution after a genuine attempt teaches you something. Reading one instead of attempting does not, which is why it takes a deliberate click and gets recorded when it happens.
Where your work lives
In a sandboxed workspace on your own machine, saved as you type. Your code and your progress sync with this site, so you can read a chapter on a phone and write the exercise on a laptop.