For anyone who wants to pick this up, I have a better idea. Communication like this has already been implemented in the Qt based IDE. It uses yaml and a custom protocol instead. The sc developers seem open to the idea of implementing lsp instead of that. Supercollider has enough introspection built in already to support these features.
I'll probably try to implement this if I get the time, if I don't I hope someone will.

The benefit to implementing LSP is that large numbers of editors and IDEs already support it. High quality interfaces and usages of that protocol are being developed all the time.

The Super Collider IDE supports a custom protocol, so the only thing that connect to that is SC IDE. The only advancement that will ever happen is by this very tiny SC community. I think it would be better to concentrate on music features unique to SC.

Agree completely, My point was to replace the existing protocol with LSP.

Oh, I misunderstood your previous comment then !

did any of you guys make progress on this?

Current setup:
- qtIDE has a class sc_introspection.hpp which talks to ScIDE.sc file in scide_scqt
- from where it gets all information, such as method names, class names.
- Also look at the Document.sc class.
Relevant directories:
- scide_scqt
- editors/sc-ide