Studying the Google Analytics - data access API

Google Analytics API

Parts: (https://developers.google.com/analytics/)

Data Input:- ( Libraries and SDKs for measurement )
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Data processing:-  ( APIs for reporting and configuration )

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Note:
Core Reporting API has versions 3 and 4 both functional.
All others are still at v3


Amazing explorer:
https://ga-dev-tools.appspot.com/dimensions-metrics-explorer/
https://ga-dev-tools.appspot.com/query-explorer/