Every time a Bitbucket API request is made which specifies a user, the request is based on the Atlassian Account ID (AAID).
Until last week, there wasn’t a way to programmatically retrieve the AAID from the user’s email.
We are glad to share that the “List users in a workspace” endpoint has been enhanced and now supports the option to query for a user AAID based on their email via the q=user.email IN ("user1@org.com","user2@org.com") filtering option.
Edmund, our Bitbucket extensibility product manager shares more about possible use cases in this post: New user-lookup API for Bitbucket Cloud.
As a reminder, you can follow the Bitbucket changelog to hear about any recent changes, here is the link to this one: User email address filtering support for List users in a workspace API.
Cheers,
Caterina