OneSignal

We are using OneSignal to handle our push notifications. They assign each install an id which we adopt and use in our service install tracking. This document is to capture what I have been able to determine about the durability of their install ids.

From their documentation

When does the OneSignal User / Player ID change? It will stay the same as long as the user has your app installed or for web push as long as the user does not clear their browser data for your site. If the user hasn't opted out of the Google Ad id (Android) the ID will stay the same after fully re-installs. On iOS the IFV (Identifier For Vendor) is used to keep the ID the same after a full re-install but only if the user as another one of your apps installed.

Based on personal testing

• Uninstall and reinstall Patchr: install id stayed the same.
• Reset the advertising id: install id stayed the same.
• Delete install from one signal: First call back to idsAvailable used the original install id. A second callback to idsAvailable used a new install id. The one signal service had a new install record using the new install id. Log shows a 400 warning from the one signal service to the one signal sdk that the device type is invalid.