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The Slack Message trigger starts your Workflow whenever a message is posted in a Slack channel or sent as a direct message to Cassidy. Use it to automate follow-up, route requests, or process inbound messages automatically.
1

Add the Slack Message trigger

Create a workflow with a Slack Message trigger, use an existing workflow with a Slack Message trigger, or change an existing workflow’s trigger type to a Slack Message trigger.
Workflow builder showing the Slack Message trigger selected
2

Connect your Slack account

If you haven’t already, connect your Slack account to Cassidy.
Slack connection prompt in the trigger configuration
3

Choose the message event type

Select either Message in Channel to run the workflow when a message is posted in a Slack channel, or Direct Message to trigger the workflow when a direct message is sent to Cassidy.
4

Select the channel

If you chose Message in Channel, select the Slack channel where you want the trigger to listen for messages.
Channel selector dropdown in the Slack Message trigger
Private channels only appear after Cassidy has been added. In the desired channel, send /invite @Cassidy.
5

Reference the trigger variables

In subsequent Workflow steps, you can reference the following variables from this trigger:
  • Message Contents — the content of the message posted in Slack
  • Message with History — full conversation history from the Slack channel, including previous messages and responses from Cassidy and other users
  • Message with Thread History — thread-specific conversation history if the message is part of a thread
  • Thread ID — the unique identifier for the thread if the message is part of a thread
  • Channel ID — the unique identifier for the Slack channel where the message was posted
  • Message ID — the unique identifier for the specific message
  • Message Attachments — any files or attachments included with the message
  • Sent By User — user information for the person who sent the message, including their Slack user ID, display name, and other profile details
Variable picker showing available Slack Message trigger outputs
6

Activate the trigger

In the Slack Message trigger block, click the toggle switch to turn it on.
Toggle switch to activate the Slack Message trigger