val route =
      pathSingleSlash {
        complete("root")
      } ~
        pathPrefix("digit") {
          pathEndOrSingleSlash {
            complete("here a digit")
          } ~
            path(IntNumber) { int =>
              complete(if (int % 2 == 0) "even digit" else "odd digit")
            }
        }


вот так было в метакомерсе


  val photos: Route = pathPrefix("photos") {

    path("get") {
      (get & parameters("sessionId") & extractExecutionContext) { (sessionId, ec) =>
        implicit val _ec = ec
        extractAuthContext { auth =>
          log(auth, None) {
            val filter = PhotoFilter(sessionIds = List(sessionId))
            onSuccess(LoadPhotosStream(filter).runWith(Sink.seq[Photo]).map(_.toList)) {
              case Nil => complete(404 -> ApiResponse(404, message = Some("session not found")))
              case result => complete(result)
            }
          }
        }
      } ~
      (post & extractExecutionContext & extractStrictEntity(10.seconds)) { (ec, entity) =>
        implicit val _ec = ec
        extractAuthContext { auth =>
          log(auth, None) {
            val f = for {
              req <- entity.convertTo[PhotosRequest]
              result <- LoadPhotosStream(PhotoFilter(ids = req.ids)).runWith(Sink.seq[Photo]).map(_.toList)
            } yield result

            onSuccess(f) {
              case Nil => complete(404 -> ApiResponse(404, message = Some("photos not found")))
              case result => complete(result)
            }
          }
        }
      }
    } ~
    path("add") {
      post {
        request[List[Photo], String] { case (auth, rc, ec) =>
            implicit val _ec = ec
            FutureUtil.serialise(rc)(photo => photoStorage ? SavePhoto(photo, refresh = true, Progress.None, auth)).map(_ => "ok")
        }
      }
    }
  }