Wish: /menu/ tree

When I create a new article, I need to give a menu id with it.
Actually I'm missing a /menu/ function in the api, which returns (like e.g. /category/) the whole menu tree. This is usally (at least in my case) different from the category tree.

(My) Goal is:
Creating a dropdown box to choose the menu item from, like in article editing mode within Joomla.