I was so happy they had finally gone native.

The disappointment is strong.

On a side note, SBlack, a lightweight slack client is very impressive on memory usage [1].

1. https://www.sblack.online/

How does this work? I thought Slack deprecated their IRC gateway; is this all API-based then?

> Sblack works exactly like a browser with small tweaks.

Looks like it just wraps the website in this case.

Yes there are clients that use the API. Slack offers a http rest-like api as well as a websockets realtime api. For example, wee-slack[1] (weechat plugin for slack) and slack-term[2] (curses client in golang).

[1]: https://github.com/wee-slack/wee-slack

[2]: https://github.com/erroneousboat/slack-term