Customized node-red features

Hello,

Is it possible to add a new feature or change some features of the node-red like as add a custom nodes?
So here is what I mean:
Node-red has got some core functions and menus like as Export & Import. I would like to change/replace them my custom features like as custom node and I don't want to change to core functions too.
Like as Library Store API : Node-RED but also I would like to add other user featured menus too.
I looked some hooks but I couldn't find yet.

Have a good coding.