Castella Core UI Development

Castella is a pure Python cross-platform UI framework for desktop (GLFW/SDL2), web (PyScript/Pyodide), and terminal (prompt-toolkit) applications. Write once, run everywhere with GPU-accelerated rendering via Skia.

When to use: "create a Castella app", "build a Castella UI", "Castella component", "add a button/input/text", "use reactive state", "layout with Row/Column", "change the theme", "handle click events", "preserve scroll position", "animate a widget"

Quick Start

Create a minimal Castella app:

from castella import App, Text
from castella.frame import Frame

App(Frame("Hello", 800, 600), Text("Hello, Castella!")).run()

Install and run: