Stencyl supports Code Mode, a way to write behaviors entirely using code (currently, Haxe).
This article surveys the interface and explains how to accomplish crucial tasks, such as defining attributes through annotations.
The Top Tool Bar
This area has four separate buttons, Check Syntax, Refresh Attributes, Open in External Editor, and View API.
Check Syntax: This checks your code's syntax for errors. Refresh Attributes: This updates the attributes in your Behavior by running an annotation parser over it. Open in External Editor: This allows you to use an IDE of your choosing, such as Eclipse, Notepad++, FlashDevelop, etc. View API: Lets you view Stencyl's ActionScript-based API.
The Attributes Pane stores all attributes currently defined by this behavior. To define attributes, you have to annotate them. See Code Mode Part 2 For More Help.