slack-multi-channel-invite

Have you ever googled "slack invite user to multiple channels"? Yeah, me too. I do this every time a new engineer joins my team, and I inevitably end up inviting said engineer to each Slack channel manually. I got tired of this, so I rolled up my sleeves and whipped up this script.

I assume Slack will eventually add this ability. Until then, hopefully you can save some time by using this.

Enjoy!

Instructions

1. Create a Slack App for your workspace.
2. Add the following permission scopes to a user token (bot tokens aren't allowed channels:write):
   • users:read
   • users:read.email
   • channels:read
   • channels:write
   • groups:read (only if inviting to private channels)
   • groups:write (only if inviting to private channels)
3. Install app to your workspace which will generate a new User OAuth token
4. Download script:
   • If you have Go installed: go install github.com/jamietsao/slack-multi-channel-invite@latest
   • Else download the binary directly: https://github.com/jamietsao/slack-multi-channel-invite/releases
5. Run script:

slack-multi-channel-invite -api_token=<user-oauth-token> -emails=steph@warriors.com,klay@warriors.com -channels=dubnation,splashbrothers,thetown -private=<true|false>

The users with emails steph@warriors.com and klay@warriors.com should be invited to channels dubnation, splashbrothers, and thetown!

* Set private flag to true if you want to invite users to private channels. As noted above, this will require the additional permission scopes of groups:read and groups:write

Want to remove users from channels?

Simply set the optional action flag to remove (add is the default):

slack-multi-channel-invite -api_token=<user-oauth-token> -action=remove -emails=kd@warriors.com -channels=dubnation,warriors -private=<true|false>

Implementation

Initially, I figured this script would be a simple loop that invoked some API to invite users to a channel. It turns out this API endpoint (conversations.invite) expects the user ID (instead of username) and channel ID (instead of channel name). Problem is, it's not very straightforward to get user and channel IDs. There isn't a way to lookup a user by username (only by email). And there's no way to look up a single channel, unless you have the channel ID already (chicken and egg).

For these reasons, I wrote the script like so:

1. Look up Slack user IDs for all given emails.
2. Query all public (or private) channels in the workspace and create a name -> ID mapping.
3. For each of the given channels, invite the users to the channel using the user IDs and channel ID from steps 1 & 2.