How to attach arbitrary key-value metadata to node or edge

Is there any way I can attach metadata to a node or edge?

A simple key-value store (akin to Go maps) would do just fine.

My wild guess it’s not possible as I could not find map/hash in the type system, but I’m wondering maybe I missed something.

I understand Edges have facets and that’s nice but they don’t quite tick the box for arbitrary data (I’d be happy with some size limit imposed on the metadata)

Can you elaborate on your experience with facets? They are the only thing close to the idea of “Metadata”. There is no other. If I understand what is happening to your use case. I could guide you.