W3C is reaching the final stages for Micropub, https://www.w3.org/TR/micropub/
Its a simple generic API for post creation, so ideally people could use any micropub client to post to their mastodon account.

• I searched or browsed the repo’s other issues to ensure this is not a duplicate.
• This bug happens on a tagged release and not on master (If you're a user, don't worry about this).