OneJS v1.6.10 is a Scripting Engine and UI Solution specifically designed for Unity. It is lightweight, performant, and built entirely in C#, with first-class TypeScript support, making it compatible across all Unity environments. Familiarity with React and TypeScript is recommended. The key advantage of OneJS is the ability to design UIs using the React (JSX) workflow, achieved through a thin layer of "dom" based on Preact. Under the hood, it uses pure UIElements, ensuring high performance. The UI Toolkit's controls, events, vector API, and styling work seamlessly out of the box. With OneJS, developers no longer need to recompile C# scripts every time UI code changes, resulting in significantly faster iteration—especially with built-in Live Reload. In addition to UI, OneJS enables the creation of addon systems, allowing players to build and customize game content using TypeScript, JSX, and CSS. Supported engine version: 2022.2.5 or higher.
