Slack clean all messages (~8K) in a channel

Question

We currently have a Slack channel with ~8K messages all comes from Jenkins integration. Is there any programmatic way to delete all messages from that channel? The web interface

Answer 1

For anyone else who doesn't need to do it programmatic, here's a quick way:

(probably for paid users only)

1. Open the channel in web or the desktop app, and click the cog (top right).
2. Choose "Additional options..." to bring up the archival menu. notes
3. Select "Set the channel message retention policy".
4. Set "Retain all messages for a specific number of days".
5. All messages older than this time are deleted permanently!

I usually set this option to "1 day" to leave the channel with some context, then I go back into the above settings, and set it's retention policy back to "default" to go continue storing them from now-on.

Notes:
Luke points out: If the option is hidden: you have to go to global workspace Admin settings, Message Retention & Deletion, and check "Let workspace members override these settings"