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

Solution 1:

I quickly found out there's someone already made a helper: slack-cleaner for this.

And for me it's just:

slack-cleaner --token=<TOKEN> --message --channel jenkins --user "*" --perform

Solution 2:

I wrote a simple node script for deleting messages from public/private channels and chats. You can modify and use it.

https://gist.github.com/firatkucuk/ee898bc919021da621689f5e47e7abac

First, modify your token in the scripts configuration section then run the script:

node ./delete-slack-messages CHANNEL_ID

Get an OAuth token:

1. Go to https://api.slack.com/apps
2. Click 'Create New App', and name your (temporary) app.
3. In the side nav, go to 'Oauth & Permissions'
4. On that page, find the 'Scopes' section. Click 'Add an OAuth Scope' and add 'channels:history' and 'chat:write'. (see scopes)
5. At the top of the page, Click 'Install App to Workspace'. Confirm, and on page reload, copy the OAuth Access Token.

Find the channel ID

Also, the channel ID can be seen in the browser URL when you open slack in the browser. e.g.

https://mycompany.slack.com/messages/MY_CHANNEL_ID/

or

https://app.slack.com/client/WORKSPACE_ID/MY_CHANNEL_ID

Solution 3:

default clean command did not work for me giving following error:

$ slack-cleaner --token=<TOKEN> --message --channel <CHANNEL>

Running slack-cleaner v0.2.4
Channel, direct message or private group not found

but following worked without any issue to clean the bot messages

slack-cleaner --token <TOKEN> --message --group <CHANNEL> --bot --perform --rate 1 

or

slack-cleaner --token <TOKEN> --message --group <CHANNEL> --user "*" --perform --rate 1 

to clean all the messages.

I use rate-limit of 1 second to avoid HTTP 429 Too Many Requests error because of slack api rate limit. In both cases, channel name was supplied without # sign

Solution 4:

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"