Zoom API - Retrieving participants and referencing them across multiple meetings

Relevant API Endpoint


I am developing a way to import data from Zoom to my app.

Using the above endpoint, I am trying to retrieve a list of participants for a meeting and then store a reference for them so that I can identify them in future meetings.

However, the above endpoint seems to provide no way to uniquely store a reference for that individual, and the ones that might have a caveat, listed below:
id - Not always available, seems to only be available if the Zoom user is a user in the account to which the OAuth access token is granted for.
user_id - A unique ID assigned to the participant joining a meeting and is valid for that meeting only.
registrant_id - Only available when registration is enabled for the meeting? The endpoint documentation is perhaps unfinished… the schema talks about query parameters that are not mentioned in the query parameters section, but I presume it’s also only unique to that meeting?
user_email - Not always available (Using Zoom APIs)

So the issue I’m having is, how can I locally store a reference to a user who’s attended a meeting, so that I can identify that exact user in future meetings?

Would enabling registration for every meeting provide a “registrant_id” that can be used to reference users outside of that meeting? Or is the registrant_id also unique to that specific meeting, and the future meetings (with their own registration) would be under a separate registrant_id?

I’d appreciate any help!

Kind regards.