Cloud Functions for Firebase: can you detect app uninstall?

Question

Is it possible to trigger a Cloud Function when the user uninstalls the app, so that we can clean up the anonymous user realtime database entry?

Answer 1

You can detect app uninstall for Android as an automatically collected Analytics event called app_remove. Then you could trigger a Cloud Function to run when that event occurs. You would also need to use the Firebase Admin SDK to access the database. Check out some of the Cloud Functions for Firebase GitHub samples to see examples of using Analytics triggers and using the Admin SDK. The function could work something like this:

exports.appUninstall = functions.analytics.event('app_remove').onLog(event => {
  const user = event.user; // structure of event was changed            
  const uid = user.userId; // The user ID set via the setUserId API.

  // add code for removing data
});