For LSP-related plugins for geany, there's some: https://github.com/notetau/geany-jedi-complete - for Python https://github.com/notetau/geany-clang-complete - for C/C++/ObjC using libclang https://github.com/notetau/geany-complete-core - core for above two https://github.com/jakeanq/gycm - YouCompleteMe plugin for Geany utilizing ycmd server. I hope that at least some of them will be in this repository :)