I wanna collect all userId and clientId from GA.
I can see userId in dashoboard:
but I can't find how get same info from APi for All user. How I can do that with Reporting API?
UserId
and ClientID
are custom dimensions. So use ga:dimensionXX
and replace XX with indexes of your custom dimensions.
https://ga-dev-tools.appspot.com/dimensions-metrics-explorer/