Zoom participantUUID changes when a participant leaves and rejoins a meeting

Zoom Apps Configuration
Ruby on Rails / JS

I am working on a Zoom app and I tested having a registered (and unregistered) participant leave and re-join a meeting. When the participant re-joins they get a new participantUUID. I saw here GetUserContextResponse | @zoom/appssdk - v0.16.12 that is says the participantUUID is “A meeting-specific participant-identifier - it persists as users navigate between breakout rooms or briefly loses connections”. Based on this I would think the participantUUID should stay the same if I leave and re-join a meeting within 30 seconds time as a registered participant, but I’m guessing this is not the case from what I’m seeing.

I am wondering if there is any way to tell if someone who left and re-joined the meeting is the same person aside from seeing if the name is the same (since two people can have the same name)?

Thank you for your help,


I figured out a good solution for the issue if anyone else faces this same problem - you can set up a webhook for a Zoom App and I’m setting the webhook for the event “Participant/Host joined meeting” this way you can get user information when they join and if someone leaves and rejoins you can trace this by their email and update their pariticipant UUID if you are storing it.

Hi @elenab , thanks for posting your solution. This is expected behavior, as for our view, this is a new participant join event. Participant UUIDs will be newly generated on each event for a number of reasons (ex: the user is not on the same account as the host; the user is not logged in, etc).

Adding participants as registrants to a meeting will allow you to distribute unique links for each participant. A participant who joins with a registration link will have their registrant_id and participantUUID match in meeting.participant_joined webhook events and past meeting APIs.