deslackify

A tool to remove your own slack messages.

deslackify can only delete messages that you sent. The token you provide authenticates as your own account, so it cannot remove messages authored by other users.

deslackify supports Python 3.10 through 3.14.

Installation

Install the deslackify command with uv:

uv tool install deslackify

Obtaining credentials

deslackify is meant to be run without the overhead of creating a Slack app. It authenticates as your own browser session, using two values copied from your logged-in Slack web client (https://app.slack.com):

1. Open your workspace in a browser and open the developer tools.
2. Token — in the Console, run:

   (d=>d.teams[Object.keys(d.teams)[0]].token)(JSON.parse(localStorage.localConfig_v2))

   It begins with xoxc-. This is the TOKEN below.
3. Cookie — in Application → Cookies → https://app.slack.com, copy the value of the d cookie. It begins with xoxd-. This is the COOKIE below. (deslackify re-encodes it as needed, so it does not matter whether the value is shown URL-encoded or not.)

The token and cookie must come from the same logged-in session.

Alternative: a Slack app token

If you are able to create a Slack app, you can authenticate with a user OAuth token instead of a browser session. It is more stable — it does not expire when you sign out — and needs no --cookie:

1. Create a new app at https://api.slack.com/apps ("From scratch").
2. Under OAuth & Permissions, add the User Token Scopes search:read and chat:write.
3. Click Install to Workspace and authorize the app.
4. Copy the User OAuth Token (it begins with xoxp-); use it as TOKEN and omit --cookie.

Running

deslackify --token TOKEN --cookie COOKIE USERNAME

Both values can also be supplied via the SLACK_TOKEN and SLACK_COOKIE environment variables (preferred, so the secrets do not appear in your shell history or process list):

SLACK_TOKEN=… SLACK_COOKIE=… deslackify USERNAME

Or run it once without installing:

uvx deslackify --token TOKEN --cookie COOKIE USERNAME

Use --dry-run first to preview what would be deleted without deleting anything.

By default deslackify will remove USERNAME's messages that are more than a year old. You may also manually specify a before date via:

deslackify --token TOKEN --cookie COOKIE --before YYYY-MM-DD USERNAME

Note: If no results are found, you may need to replace USERNAME with USERID. You can find the USERID by going to Profile & Account, and then clicking the three dots, and at the bottom, "Copy member ID".