As I was preparing to publish an Android app I wrote which uses the Google Play in-app purchase API, I noticed in the LogCat there appear entries similar to this:
TRuntime.CctTransportBackend Making request to: https://firebaselogging.googleapis.com/v0cc/log/batch?format=json_proto3
Googling this, I find CctTransportBackend.java on GitHub which is part of Firebase. After spending a few hours trying to figure out which of my dependencies is doing this, I find that the com.android.billingclient:billing:6.0.1 is the one that includes Firebase.
Okay, so I suppose it's unavoidable if I want to keep my in-app purchase in the app in order for me to be paid for all that development work. But why? What exactly does Play Billing send to its Firebase backend?
Specifically, Google Play requires me to write a Privacy Policy for my app. I am supposed to report to the user what information the app collects - even if I never see that information as it's collected by a dependency. What do I put in the Privacy Policy regarding this? Does Google document what they collect there?
Thank you.
I answered a questions about this a while ago, but can't find it anymore.
The call you're seeing is present in many Google apps and SDKs as they all share a common logging infrastructure. Nowadays this logging infrastructure has many endpoints (URLs) that apps can use, but many still use the Firebase URL.
The data sent to this API is dispatched to the correct backend processes, and only processed by Firebase when it actually comes from one of the Firebase SDKs. Since you're not using Firebase in your app, Firebase doesn't actually process the data in the request beyond what it needs to determine where to send it.