Giving realtime access to third parties?

[well-made-uk]

I'd like to use Supabase Realtime to provide a realtime stream of new submissions to third-party clients, for conferences.

I can very easily subscribe to new entries in the database using the JS client, but I need to provide access to third-party clients. I am comfortable creating back-end functions and working with the Supabase API in general, but so far it's all been internal with limited concern for security, and I've got no clue as regards to webhooks/realtime stuff.

If it helps, most of our back-end stuff is just using Netlify serverless functions. I've already got a function to retrieve entries, and it uses the origin domain to determine which entries are returned (i.e. only the entries made at the conference), which is secure enough for us. It would be great if I could provide a realtime stream in the same way, but I don't know if that's possible.