Users and devices
Your user IDs
Section titled “Your user IDs”PushFleet doesn’t create users. The user ID is whatever your app already uses to identify someone: a database ID, a UUID or an opaque string. It’s case-sensitive and can be up to 128 characters. Avoid emails or names, since IDs show up in logs.
Devices
Section titled “Devices”A device is one push token from one app install. When your app registers, PushFleet stores the token against the user ID and detects the platform from the token’s shape, so you never have to say whether it’s an iPhone or an Android phone. For Apple devices the SDK also reports apns_environment (sandbox for debug builds, production for TestFlight and App Store builds), because the token can’t tell you.
Registering the same token again updates it instead of creating a duplicate. That makes it safe to call register on every launch, and it moves the token to a new user when someone signs out and another person signs in.
When tokens go stale
Section titled “When tokens go stale”Apps get uninstalled and tokens expire. When Apple or Google rejects a token as dead, PushFleet removes the device and sends a device.removed webhook. You never have to prune tokens yourself.