Assigning key-equivalent to NSToolbarItem?

Question

How can I set a key equivalent for a NSToolbarItem?

Answer 1

You don't—toolbar items don't have keyboard shortcuts. You need a menu item that does the same thing with the right shortcut.

All toolbar items should have a corresponding menu item anyway according to Apple:

A toolbar is useful for giving users immediate access to the most frequently used features in an application. Any item in a toolbar should also be available as a menu command.