They have it documented here: https://developers.google.com/analytics/devguides/collection/protocol/v1/reference https://developers.google.com/analytics/devguid

They have it documented here: https://developers.google.com/analytics/devguides/collection/protocol/v1/reference https://developers.google.com/analytics/devguides/collection... So I think it's a totally legit way to use GA, since you don't always have the ability to add libraries. For example if you want to track GA server side.