@seancorfield So to mirror a channel to Zulip, do I just invite zulip-mirror-bot?

Do I have to do anything on the Zulip side?

That should be it

@cfleming Yup. Just /invite @zulip-mirror-bot

The mirroring is not two-way, right? It’s just Slack that gets replicated over to Zulip?

@cfleming Correct. The Slack content all goes into a specific stream in Zulip with a topic for each channel. It's intended purely as a searchable archive so folks using Zulip don't "miss out" on Slack discussions -- and so Slack folks can go join Zulip in order to search the history of Slack on its own.

Zulip has a lot of streams and topics of its own that are freestanding. I don't know what it would take in terms of integration slots on the Slack side to be able to feed that Zulip content into Slack, nor am I sure where we'd want to put it (and we'd need to be careful not to have it then mirrored back into the "slack-archive" on Zulip!).

Also, where we've experimented with two-way mirroring before (with Matrix, primarily), it's created a really ugly experience on both sides because mirroring tends to lose at least some formatting and context. For example, Slack threads tend to just get mirrored as messages in a channel because it's hard to map them to other services. Integrations like GitHub etc tend to use specialized formatting that Slack offers (such as annotated, multi-part attachments to messages) and those are very hard to massage into an appropriate format in other services. And vice versa for piping messages into Slack.

When the Zulip mirroring experiment was first started, Slack channels were piped into topics within the corresponding stream but it made for a mess of communication on the Zulip side -- hence the decision to pipe everything into one stream (the downside is that now you can only subscribe to "everything" or nothing, although you can mute anything you're not interested in).

I've also tried real-time, two-way mirroring between Slack and Gitter (using a free integration that went away, unfortunately) and it was also a pretty horrible experience (for both sides).

Zulip's keyboard navigation is a big win, in my opinion, for navigating around the Slack archive over there. I can search (`/`), narrow to a given topic (`S`) or expand to a whole stream (`s`), page back and forth (`J`/`K`) or go message by message (`j`/`k`).

@seancorfield FWIW the two-way mirroring with IRCCloud actually works pretty well in my experience, although I haven’t used it much. IRC3 supports threads etc so the experience seemed pretty similar.

That said, I still just use IRCCloud as a slack history store really.

Yeah, there seems to be a bit of a sweet spot there. After using IRCCloud, I expect other integrations to be as smooth... 😞