RootJsonFormat

case class Blah(id: String, name: String)

object Blah {

  implicit val jsonFormats = new RootJsonFormat[Blah] {
    override def read(json: JsValue): Blah = {
      val js = json.asJsObject

      (js.fields("some_id"), js.fields("some_name")) match {
        case (JsString(id), JsString(name)) => Blah(id, name)
        case _ => deserializationError(s"Failed to read `Blah` from json `$json`")
      }
    }

    override def write(blah: Blah): JsValue = JsObject(
      "id" -> JsString(blah.id),
      "name" -> JsString(blah.name)
    )
  }
}