Hot key without a Menu Item

I want to make a few Keyboard shortcuts but i don’t necessary need the menu items as well.
Is that possible?

This adds a callback function to the Scene view - you can check in there for key code events. The initialize on load attribute makes it install the callback when Unity loads the project.

class MyKeyDetector
    static MyKeyDetector ()
        SceneView.onSceneGUIDelegate += CheckKeys;
    public static void CheckKeys(SceneView view)
        Event current = Event.current;
        if (current.type == EventType.KeyDown && current.modifiers == EventModifiers.Control && current.keyCode == KeyCode.G)
            Debug.Log("control G pressed!");

        // ...

Just for those wich are looking for an easier solution use : ShortcutAttribute

        /// <summary>
		/// Create a new MyCustomComponent in the selected GameObject
		/// </summary>
		[Shortcut("MyCustomAsset/Add MyCustomComponent", null, KeyCode.P, ShortcutModifiers.Shift)]
		public static void  AddComponentToSelectedGameObject (ShortcutArguments shortcutArguments) {
			GameObject[] selection = Selection.gameObjects;
			foreach(GameObject currentGO in selection) {
				if (currentGO.AddComponent<MyCustomComponent>() != null) { Debug.Log("Add MyCustomComponent"); }
				else{ Debug.Log("Not Add MyCustomComponent"); }

Then you can manage the shortCut in the Unity ShortucutManager :