Slack Socket Mode Trigger

Triggers workflow when a Slack message matches a regex pattern via Socket Mode

Overview

This node triggers workflows in n8n when specific Slack events occur via Slack's Socket Mode. It listens for a wide range of Slack event types (such as messages, app installs, channel changes, reactions, and many others) and can filter these events based on a user-defined regular expression pattern applied to incoming Slack messages. Additionally, it supports filtering events by a specific Slack channel.

Common scenarios where this node is beneficial include:

Automating responses or actions when certain keywords or patterns appear in Slack messages.
Triggering workflows on specific Slack events like app installations, channel creations, or user joins.
Monitoring interactions with Slack buttons or other UI elements.
Filtering events to only those occurring in a particular Slack channel.

Practical examples:

Automatically creating a task in a project management tool when a message matching a regex pattern is posted in a designated Slack channel.
Sending notifications or logging when a new channel is created or deleted.
Responding to button clicks within Slack messages to trigger custom workflows.

Properties

Name	Meaning
Trigger On	Select one or more Slack event types that will trigger the workflow. Options include a comprehensive list such as "App Installed", "Message", "Channel Created", "Reaction Added", "Workflow Published", and many more.
Regex Pattern	A regular expression pattern to match against incoming Slack messages. Capture groups can be used to extract data from the message content.
Regex Flags	Flags for the regular expression, e.g., `g` for global matching, `i` for case-insensitive matching, `m` for multiline, etc.
Channel to Watch	Optionally select a specific Slack channel to filter events. If specified, only events originating from this channel will trigger the workflow. Can be selected from a list or specified by channel ID.

Output

The node outputs JSON objects representing the Slack event data received. Each output item contains the following structure:

body: The raw body of the Slack event request.
payload: The payload object associated with the event (if applicable).
context: Contextual information provided by the Slack Bolt framework.
event: The actual Slack event object containing details about the triggered event.

If a regex pattern is specified, the node applies it to incoming messages but does not modify the output structure; it simply filters which events trigger the workflow.

The node does not output binary data.

Dependencies

Requires a Slack app configured for Socket Mode with appropriate permissions.
Requires an API key credential providing:
- Bot token
- App token
- Signing secret
Uses the official Slack Bolt SDK (@slack/bolt) to connect and listen to Slack events via Socket Mode.
Supports proxy configuration via environment variables HTTP_PROXY or HTTPS_PROXY.
Requires n8n credentials setup with the above Slack tokens.

Troubleshooting

Missing Credentials: The node requires bot token, app token, and signing secret. If any are missing, the node will throw an error indicating missing required Slack Socket credentials.
Invalid Channel ID: When specifying a channel by ID, ensure it matches Slack's channel ID format (starts with C, G, or D followed by at least 8 alphanumeric characters). Otherwise, validation errors will occur.
Regex Errors: Invalid regex patterns or flags may cause runtime errors or prevent proper filtering. Validate regex syntax before use.
Event Listener Setup Failures: Errors during setting up event listeners for selected triggers will be logged. Ensure the Slack app has subscribed to the requested event types.
Connection Issues: Problems starting or stopping the Slack Socket app (e.g., network issues, invalid tokens) will be logged and may prevent triggering.
Proxy Configuration: If behind a proxy, ensure environment variables HTTP_PROXY or HTTPS_PROXY are correctly set; otherwise, connection attempts may fail.