> For the complete documentation index, see [llms.txt](https://kwanjoong-dev.gitbook.io/unity-ui-storyboard/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://kwanjoong-dev.gitbook.io/unity-ui-storyboard/en/readme/undefined/key-design-concepts/reactive.md).

# Principles for using Reactive libraries

* <mark style="color:red;">**The principle is to implement using only UniTasks**</mark><mark style="color:red;">.</mark>
* Avoid UniRx due to performance issues.
* R3 (successor to UniRx) does not have significant performance issues, but for code uniformity it is recommended to avoid using it.
  * Exceptions are limited to special cases that are very easy to implement using R3.