@matty No, it’s a curated stream of Mastodon posts. You add links to posts and it streams them in a loop. So you can consume it when making a WebSocket demo or just get the public timeline for a HTTP call/JSON demo. Useful when teaching web dev, for example.
But what you describe wouldn’t be difficult to build with Kitten (https://kitten.small-web.org/).
(Streamiverse is built with Kitten and is very simple.)