The ball is in (someone's) court

Translation of "the ball is in (someone's) court" into Russian

ход за (кем-то)

I've done my part, now the ball is in your court.

Я сделал свою часть, теперь ход за тобой.

This phrase means that it is now someone else's turn to take action or make a decision. Responsibility has shifted to that person.