Reactive UI Toolkit

React-style UI for game engines.

One component model, every engine. Function components, hooks, and a fiber reconciler that diffs each render and patches only what changed — implemented natively for each engine, and authored in a JSX-like markup language that compiles to that engine's own code.

Documentation

Godot

GDScript .guitkx Godot 4.x

Plain GDScript — no C#, no autoload. Components patch a real Control tree, and .guitkx compiles to a sibling .gd with hot reload that preserves hook state.

Read the docs

Unity

C# .uitkx Unity 6000.2+

Runs entirely in C# on top of UI Toolkit, with a second render backend for classic uGUI — one fiber reconciler, two backends, the same components rendering to either.

Read the docs

Unreal

C++ .uetkx UE 5.6+

Pure C++ over real Slate widgets, with a time-sliced render scheduler and an in-editor .uetkx live preview.

Read the docs