Is there a way to access the items in a workspace's inbox via the API? I'm primarily interested in the unread count, but could make good use out of any unhidden items as well.
At the moment you can't do this with a simple API call.
You might be able to do it by pulling down all projects, and then pulling down all the tasks for each project, storing that in a local database, and then search for tasks with assignee_status set to "inbox" (https://asana.com/developers/api-reference/tasks). But that is probably not the answer you want!