Version: 3.x

Slack

Connecting a bot to Slack requires you to configure it to send messages (using API credentials) and to receive messages (using a webhook).

Sending Messages

Create a new file credentials.yml in the root folder of your Rasa project (if you've used rasa init this file should already exist and you can just edit it). Add the following lines to the file:

credentials.yml
slack:
slack_channel: "CA003L0XZ" # channel ID, not a channel name!
slack_token: "xoxb-XXX" # token obtained in the next step
slack_signing_secret: "YYY" # secret obtained in the next step

The slack_channel can be a channel or an individual person that the bot should listen to for communications, in addition to the default behavior of listening for direct messages and app mentions, i.e. @app_name. To get a channel id, right click on the channel in Slack and choose Copy Link. The id will be the last component in the URL.

In the next couple steps, you'll create a Slack App to get the values for slack_token and slack_signing_secret:

  1. To create the app go to Your Apps and click on Create New App.

    Create New App

    Fill out your App Name and select the Development Workspace where you'll play around and build your app.

  2. Head over to OAuth & Permissions and scroll down to Scopes. Scopes give your app permission to do things in your workspace.

    To get started, you should at least add the following scopes:

    • app_mentions:read,
    • channels:history,
    • chat:write,
    • groups:history,
    • im:history,
    • mpim:history and
    • reactions:write.
    Set up Slack Permissions

    In Slacks API documentation you can find a list and explanation of all available scopes.

  3. On the OAuth & Permissions page, click Install App to Workspace to add the bot to your workspace.

    Install Slack App

    Once added, Slack will show you a Bot User OAuth Access Token which you'll need to add to your credentials.yml as the value for slack_token:

    credentials.yml
    slack:
    slack_channel: "your-channel" # choose a channel for your bot
    slack_token: "xoxb-XXX" # token obtained in the next step
    slack_signing_secret: "YYY" # secret obtained in the next step

    The token should start with xoxb.

  4. Head over to Basic Information to gather the Signing Secret.

    Signing Secret

    Copy the signing secret into your credentials.yml as the value for slack_signing_secret:

    credentials.yml
    slack:
    slack_channel: "your-channel" # choose a channel for your bot
    slack_token: "xoxb-XXX" # token obtained in the next step
    slack_signing_secret: "YYY" # secret obtained in the next step

This setup will allow your bot to send messages. Now let's head over to the setup for receiving and reacting to messages.

Receiving Messages

Before continuing, make sure you have configured a Slack App for Sending Messages and have added Slack credentials to your credentials.yml file.

To receive messages, you will need a publicly available URL for Slack to reach your bot and tell you about new messages. If you are running locally, you can test channels using ngrok

  1. To configure your bot to receive messages, your bot needs to be running. Start your bot e.g. using

    rasa run

    If you are running locally, make sure ngrok (or another tool to retrieve a public url) is running as well.

  2. To send messages directly to your bot using the slack UI, head to App Home, scroll to the bottom and select the checkbox for Allow users to send Slash commands and messages from the messages tab.

    You might have to quit the Slack app and re-open it before your changes take effect.

    Messages Tab
  3. Configure the webhook by heading to Event Subscriptions and turning Enable Events on.

    As a request URL enter the public url of your bot and append /webhooks/slack/webhook, e.g. https://<host>/webhooks/slack/webhook replacing <host> with your URL. If you are using ngrok, your url should look like https://92832de0.ngrok.io/webhooks/slack/webhook.

    You won't be able to use a localhost url.

    Request URL
  4. As a last step, you'll need to Subscribe to bot events on the same page. You'll need to add the following events:

    • message.channels,
    • message.groups,
    • message.im and
    • message.mpim.
    Subscribe to Bot Events

    Make sure to hit Save Changes at the bottom of the page after you've added these events.

    (If you didn't grant all required permissions to your app while setting up sending of messages, you'll be prompted to reinstall your app which you will need to do. Otherwise, Slack will confirm your change with a Success!)

invite to channels

As per Slack docs, make sure you invite your bot to a channel it should be accessing. You can do this by using /invite in the channel.

Your bot is now ready to go and will receive webhook notifications about new messages.

Optional: Interactive Components

After you've completed Sending Messages and Receiving Messages your bot is ready to go. If you want to use Slack's interactive components (buttons or menus), you'll need to do some additional configuration:

Open the Interactivity & Shortcuts page and toggle Interactivity to be on. Afterwards, you'll need to enter the same url into the Request URL field which you used in Step 2 of Receiving Messages, e.g. https://<host>/webhooks/slack/webhook.

Enabling Interactivity

Additional Slack Options

Here is a complete overview of all the configuration parameters for the Slack connection:

credentials.yml
slack:
slack_channel: "CA003L0XZ" # channel ID, not a channel name!
slack_token: "xoxb-XXX" # token obtained in the next step
slack_signing_secret: "YYY" # secret obtained in the next step
proxy: "http://myProxy.online" # Proxy Server to route your traffic through. This configuration is optional. Only HTTP proxies are supported
slack_retry_reason_header: "x-slack-retry-reason" # Slack HTTP header name indicating reason that slack send retry request. This configuration is optional.
slack_retry_number_header: "x-slack-retry-num" # Slack HTTP header name indicating the attempt number. This configuration is optional.
errors_ignore_retry: None # Any error codes given by Slack included in this list will be ignored. Error codes are listed [here](https://api.slack.com/events-api#errors).
use_threads: False # If set to True, bot responses will appear as a threaded message in Slack. This configuration is optional and set to False by default.
conversation_granularity: "sender" # sender allows 1 conversation per user (across channels), channel allows 1 conversation per user per channel, thread allows 1 conversation per user per thread. This configuration is optional and set to sender by default.

Make sure to restart your Rasa server after changing the credentials.yml for the changes to take effect.