A standard set of rules for collecting and sending events directly to Google Analytics servers.
The Measurement ProtocolAlpha lets you send data to Analytics from your website or app. It's particularly useful when you want to send data to Analytics from a kiosk, a point of sale system, or anything that is not a website or mobile app. Because, while the global site tag and Google Analytics for Firebase SDKs automatically build events to send data to Analytics from websites and apps, you must manually build data-collection events for other kinds of devices. The Measurement Protocol defines how to construct the events and how to send them to Analytics.
Learn more about generating API secrets for Measurement Protocol.
Read about the Measurement Protocol on Google Developers.