Build a Slackbot using Hubot

Hubot is GitHub’s open-source chat robot: Node.js, scriptable in CoffeeScript or JavaScript, with adapters for the shell, Slack, and others. It is a fast way to put automation in a channel — deploys, reminders, environment locks — without building a full Slack app from scratch.

Caveat for greenfield work: Hubot is legacy. For a new Slack integration, prefer Slack’s current platform (Bolt and friends). This post is still useful if you are maintaining Hubot, learning the pattern, or cloning an existing bot like the one below.

You need Node.js and npm installed.

Generate a Hubot#

npm install -g yo generator-hubot
mkdir alfred && cd alfred
yo hubot

Run it in the shell adapter:

./bin/hubot

Try alfred help (replace alfred with the name you chose). Built-in scripts are mostly toys; the value is in scripts you write or install.

Community scripts often live on npm under hubot-*. Install one and list it in external-scripts.json.

Write a custom script#

Place CoffeeScript or JavaScript in scripts/, and export a function that receives robot.

Create scripts/alfred.coffee. Hubot indexes the header block for help:

# Description:
#   Alfred Hubot
#
# Dependencies:
#   None
#
# Configuration:
#   None
#
# Commands:
#   hubot hello - Say hello
#
# Author:
#   pradipta.sarma

module.exports = (robot) ->
  robot.respond /hello/i, (res) ->
    res.reply "Hey #{res.envelope.user.name}, what's up?"

robot.respond matches messages addressed to the bot (alfred hello). res carries sender, room, and message metadata.

Reload or restart Hubot, then:

alfred hello
# => Hey Shell, what's up?

On Slack, the username is the Slack user, not Shell.

From here you can add more robot.respond / robot.hear handlers, call HTTP APIs, write to Hubot’s brain (Redis by default in many setups), or talk to an external database.

Connect to Slack#

In your workspace, add the Hubot app (or create an integration that yields a bot token — Slack’s Hubot listing has moved over the years; follow current Slack docs for bot tokens if the classic Hubot app is gone). Set the token and start with the Slack adapter:

HUBOT_SLACK_TOKEN=xoxb-your-token ./bin/hubot --adapter slack

Invite the bot to a channel and try alfred ping — you should get PONG if the stock scripts are enabled.

Why I built Alfred#

At a previous company, “Winky” reserved dev and staging environments so two people did not deploy over each other. You could see who held an instance and coordinate. I wanted the same thing at my then-current workplace, so I built Alfred on Hubot and Slack. Credit for the inspiration: Nemo.

The code for that bot is in pradipta/alfred.

If you are starting today and do not need Hubot compatibility, build on Slack Bolt. If you need to understand or extend a Hubot that already runs the floor, the generate → script → adapter path above is still the map.