akka-http-fun

  val routes =
    (post & path("graphql")) {
      optionalHeaderValueByName("ACCEPT_LANGUAGE") { accept_language =>
        entity(as[JsValue]) { requestJson =>
          val context = Context.from(accept_language)
          println("ACCEPT_LANGUAGE: " + context.language)
          graphQLEndpoint(requestJson, context)
        }
      }
    } ~
    {
      get {
        getFromResource("graphiql.html")
      }
    }