Is it possible to make an editor GUI?

Hi all,
Simple question, Is it possible to make an editor GUI. What are the classes that I can use for this?
Because I have a hard time of finding good information on the website.

Your question is extremely vague, what kind of GUI do you want exactly?

https://forums.unrealengine.com/showthread.php?2916-Tutorial-Intro-to-Editor-Customization-with-Plugins seems relevant to your query

Thnx that is close for what what I’m looking for.
Sorry for being vague I come from Unity background and in unity it’s like 3 lines for creating a custom editor UI window.

Use Slate, its same ui system that ue4 editor uses, search slate in docs or wiki