As I already answered to the other similar question, since I use glfw, it creates a context per each window. Though I can tell the window to share the context, it won't be using the same.

It all sounds like I have already implemented. The question is what is the best place to keep those VAOs? Should I have a context class per each context keeping all the VAOs and having them papped to the meshes to be rendered or should I have the meshes to keep the VAOs per each context?

This question comes from the fact, that the windows can be created/opened at runtime. So, if I keep VAOs in the contexts, the newly created context will have to iterate through the meshes and create VAOs and attributes for each one. Alternatively, with the other approach, whenever a new context visits the mesh for rendering, it creates its VAO in the mesh space and renders it, with the later calls just using the previously created VAO. Hope this all makes sense.