What happens if an user isn't active on a segment

Hi
i’m using yr api for further development on my server. I wnat know what happens if an id isn’t stored on yr system.
Let me do an example.
I stored uid on my DB and use these ids to send customized notification.
An user can clear his cache or change device and will subscribe again adding an uid (or replacing last one on first case). So I’ll have an error if notifications are sent to uid that aren’t on yr system?

You are correct. If you are using https://docs.webpushr.com/fetch-subscriber-id method to store uid in your DB, please plan to update it periodically, as it will change for an individual over time.

Please take a look at Limitations section for fetch sid method in our documentation.