Looking at google's AMP documentation, seems like clientID is a great way to store a unique user id. But how can I translate that through my regular non amp page? If a user sees an AMP page and got a clientID, then they performed some operation which led them to land on non AMP page. As I don't have access to old cookies on google's cache domain, how can I relate AMP clientID with my new generated clientID on NON AMP page?
Creating a proxy as shown in https://github.com/andreban/amp-publisher-sample/commit/c455a2d117a8899dcb201f93e17889f4d2681cd3 should work for this case. Note that the example is for google analytics but you can easily use the technique for other providers