Supabase is an open source Firebase alternative. Start your project with a Postgres database, Authentication, instant APIs, Edge Functions, Realtime subscriptions, and Storage.

Supabase

The lack of transaction support is a major blocker for me with Supabase. I know it's possible via postgres functions, but if I have payment webhook I need to be doing the transaction logic in my code.

You can make the webhook hit a SQL function through the REST API. Btw, you can see a curl example of how to call a function on your API docs.

With that, you wouldn't need to handle transaction logic in your frontend code.