by niftylettuce



A little server that enables public access to a Slack server. Like Freenode, but on Slack.

It provides

  • A landing page you can point users to fill in their emails and receive an invite (
  • An <iframe> badge to embed on any website that shows connected users in realtime with
  • A SVG badge that works well from static mediums (like GitHub README pages)

Read more about the motivations and history behind Slackin.

How to use





Deploy to Azure


Follow these instructions.

Cloud Foundry

IBM Bluemix

Deploy to Bluemix

For other CloudFoundry providers, follow these instructions.


Install it and launch it on your server:

$ npm install -g slackin
$ slackin "your-team-id" "your-slack-token"

Your team id is what you use to access your login page on Slack (eg: https://{this}

You can find or generate your API test token at – note that the user you use to generate the token must be an admin. You need to create a dedicated @slackin-inviter user (or similar), mark that user an admin, and use a test token from that dedicated admin user. Note that test tokens have actual permissions so you do not need to create an OAuth 2 app. Also check out the Slack docs on generating a test token.

The available options are:

Usage: slackin [options] <team-id> <api-token>


  -?, --help                 output usage information
  -v, --version              output the version number
  -p, --port <port>          Port to listen on [$PORT or 3000]
  -h, --hostname <hostname>  Hostname to listen on [$HOSTNAME or]
  -c, --channels [<chan>]    One or more comma-separated channel names to allow single-channel guests [$SLACK_CHANNELS]
  -c, --channel <chan>       Single channel guest invite (deprecated) [$SLACK_CHANNEL]
  -i, --interval <int>       How frequently (ms) to poll Slack [$SLACK_INTERVAL or 5000]
  -P, --path                 Path to serve slackin under
  -s, --silent               Do not print out warns or errors
  -c, --css <file>           Full URL to a custom CSS file to use on the main page

Important: if you use Slackin in single-channel mode, you'll only be able to invite as many external accounts as paying members you have times 5. If you are not getting invite emails, this might be the reason. Workaround: sign up for a free org, and set up Slackin to point to it (all channels will be visible).

Realtime Badge

<script async defer src=""></script>

or for the large version, append ?large:

<script async defer src=""></script>


<img src="">

Done in Markdown this looks like:

[![Slack Status](](

Landing page

Point to

Note: the image for the logo of the landing page is retrieved from the Slack API. If your organization doesn't have one configured, it won't be shown.


Requiring slackin as a module will return a Function that creates a HTTP.Server instance that you can manipulate.

  token: 'yourtoken', // required
  interval: 1000,
  org: 'your-slack-subdomain', // required
  path: '/some/path/you/host/slackin/under/', // defaults to '/'
  channels: 'channel,channel,...' // for single channel mode
  silent: false // suppresses warnings

This will show response times from Slack and how many online users you have on the console.

By default logging is enabled.

The returned http.Server has an app property that is the express application that you can define or override routes on.


All the metadata for your organization can be fetched via a JSON HTTP request to /data.

If you wish to turn on CORS, pass -x or --cors to slackin.


Slackin's server side code is written in ES6. It uses babel to transpile the ES6 code to a format node understands. After cloning Slackin, you should install the prerequisite node libraries with npm:

$ npm install

After the libraries install, the postinstall script will run gulp to invoke babel on the source. It is important to run gulp manually after updating any files in lib/ to update the versions in node/.


  • The SVG badge generation was taken from the excellent shields project.
  • The button CSS is based on github-buttons.