When we last tried this it was a fairly poor experience on both sides since the formatting and username stuff doesn't translate well. In addition, since we may lose sponsorship and drop to a free plan at any time, we have historically denied nearly all integrations (because they are limited on the free plan) so it's unlikely we would let you add the integration here anyway.

A one-way bridge, from Slack to some other system, would be considered -- we have logbot which mirrors Slack channels to a logging system on ClojureVerse and we have zulip-mirror-bot which mirrors Slack channels to a stream in the Clojurians Zulip Chat. Those don't "pollute" this Slack with messages from outside so the experience of Slack users here is not affected. Formatting/content etc is lost through both of those mirrors tho'...

Okay, thanks, so there would be a problem that if I add a bridge to slack on my matrix server, it would generate annoying messages on the slack end? I see, that would indeed not be desirable.

It would likely generate poorly formatted messages with unverifiable usernames, yes. Which is why we won't allow bridges in, only bridges out.

tnx