Type definitions for LuaTeX.
The development of the definitions for LuaTeX takes place in this repository: https://github.com/Josef-Friedrich/LuaTeX_Lua-API
There is also a Visual Studio Code extension: https://marketplace.visualstudio.com/items?itemName=JosefFriedrich.luatex
Development repository of LuaTeX (including C source code and source code of the manual):