Are there any kind of Scriptable Brushes?

Just curious - does Krita has any kind of scriptable brushes? I mean brush, that can execute script that sample colors and write them back into layer. I`m using FireAlpaca that allow Lua scripting for brushes (and this is essential for some custom workflows i use) and looking to switch into Krita

No. Adam Celarek once wrote a proof of concept of a scriptable Lindenmayer brush (lindenmayer | Adam Celarek's blog), but that was never finished. If this is essential for you, you will have to write a new brush engine in C++.