Ask HN: How to capture private slack channel conversations

When a incident happens at work, someone from my team sets up a private slack channel (war room) and invites a select number of people to join and work the incident. After the incident is remediated, we attach the screen shots from the war room on to the corresponding ticket as artifacts. There has to be a better way at accomplishing this and produce a better output, like a text file. Does anyone know of a bot or slack app that we can invite into a private slack channel that does nothing but capture all of the conversations and logs it into a usable format for attaching into a ticket? I've searched and haven't found much and it seems like it might need to be a custom bot, but before I go off and design something, maybe someone already has built something like this?

Thanks in advance.