You need to provide Accept header in your request.
Hi Anton, i have included Accept: application/json header, but still response NullPointerException (... < DateUtil:64 < PositionResource:67 < ...)

Actually the problem is that you haven't provided from and to parameters.
Hi, when I call API Method /api/positions/?deviceId={id} it's return
but when no parameter, it's normal (return list of position of all devices)
Thank You