It's officially documented here: https://developers.google.com/analytics/devguides/collection/protocol/v1/reference https://developers.google.com/analytics/devg

It's officially documented here: https://developers.google.com/analytics/devguides/collection/protocol/v1/reference https://developers.google.com/analytics/devguides/collection... So I think they won't change it or just add a different version with the old version still working.