Called when user clicks a keyboard key and sidebar is active. The event will only be triggered if .keyboard property of the sidebar is true. You can add event listener during the object creation: let sidebar = new w2sidebar({ name : 'sidebar', nodes: [ { id: 'id-1', text: 'Level 1' }, { id: 'id-2', text: 'Level 2' }, { id: 'id-3', text: 'Level 3' } ], onKeydown: function(event) { console.log(event); } }); or after the object has been created: w2ui.sidebar.on('keydown', function(event) { console.log(event); }); The event handler is called before the default action of the event is triggered. You can cancel the default action by calling event.preventDefault(). To perform an action after the event is fully processed, define event.onComplete function. See events page in utilities for more details.