@simon I think that may have been it! I’ll be honest, I’m a little confused by how the Slack app works. Since I was able to run /discourse ... commands in any Slack channel and the “App” seemed to be installed at a global level, it seemed I had “added” the app in every way necessary. However, when I explicitly /invite my discourse app user into another channel, it starts working!
/invite @Discourse
/discourse post 20
What’s very annoying about this is that Slack doesn’t even show me that my @discourse user is in my channel after I add it. The number of users in the Slack UI does not change, and if I view all the members of the channel, my app user is not listed there. I suppose this is a deficiency of Slack itself, not Discourse.
It would be nice to not need to invite the discourse user into every Slack channel in my team (goodness knows, we have a ton of channels) but I assume this must be a Slack limitation for apps? Also, is there an enhancement we can add to the Discourse chat plugin to detect this issue and display a more useful error message?