Aware, well-informed; in the know. Often in to be (also get) hip to something: to be or become aware of or well-informed about something.

colloquial (originally and chiefly U.S.). Of a person: smart, well-informed, hip; following the latest trends and fashion. Also, of a thing…

Characteristic of or like a hipster (hipster, n.2 2); having the language, style, or manner of a hipster; (now) esp. sophisticated, cool.