Apple will integrate Siri to OS X in 10.12
Apple created the Siri for the iOS few years ago, and since than Apple is improving its voice assistant. However, it was expected from Apple to bring its own assistant to MacBook. Latest rumor says it will.
Rumor indicates that Siri will be integrated into OS X in the next update: OS X 10.12 which will be introduced in this June. Siri will be placed into the menu bar, and when you click the icon, there will be a transparent interface that will appear in the upper right side.