1) What you are referring to is called editor scripting and it is done via a class that is called EditorScript. What you need instead is to create a Pugin via the EditorPlugin class. This enables you to add gui elements to the Godot editor. There are a few tutorials about it on YouTube. 2) So yes it is possible. You could create some basic gui using EditorScript too, but I 've read somewhere that you cannot listen to user input (button presses) . 3) If you decide to go for EditorScript, which is a bit simpler, you could create a slider or an export variable and have them react to changes from within the editor. You have to use the setget keyword when you define the slider or the variable.