Actor.scala

import akka.pattern.ask
import akka.pattern.pipe
//case 1:
class ServiceActor extends Actor {

	//...
	def receive = Receive {
		case DoSomeVeryComplexCalculationsRequest(taskDef) => 
			(specialAgent ? DoTheMath(taskDef)).mapTo[Option[User]] pipeTo sender
	}
	//...

	def specialAgent = context actorOf SpecialAgent.props
}

// case 2:
class HttpRouteHandlerActor(repository: ActorRef) extends Actor {

	//...
	def receive = {
		case GimmeUser(id) => 
			(repository ? GetUserFromRepo(id)).mapTo[Option[User]] pipeTo sender
	}
	//...
}