This is a browser app that displays a Mastodon thread of your choosing on one convenient page.
Probably not. Maybe in the future.
Because I'm using the Mastodon API to get the data.
Because I don't know how to get a specific post from a server using ActivityPub. I'm not even sure if that's possible.
You already did.
You copy-paste the URL of any post in the thread into the Box above and click Unroll. It'll then generate the page right in your browser.
Magic. And the code here. But mostly Magic.
That's not a question.