Slack MCP Server

A powerful Model Context Protocol (MCP) server that enables seamless integration with Slack workspaces. This server provides comprehensive tools for sending messages, managing channels, uploading files, and accessing workspace information, making it easy to automate and enhance your Slack workflows through AI assistants and other MCP-compatible applications.

Overview

The Slack MCP Server bridges the gap between AI-powered applications and your Slack workspace, providing a rich set of capabilities for both reading and writing Slack data. Whether you need to send notifications, retrieve channel information, react to messages, or upload files, this server exposes all the essential Slack functionality through a standardized MCP interface. It supports advanced features like threaded conversations, emoji reactions, and flexible channel filtering, making it suitable for everything from simple notifications to complex workflow automation.

Features

• Message Management: Send messages to channels, direct messages, or threads with full text formatting support
• Channel Discovery: List and filter channels by type, access level, and archive status
• Reaction Support: Add emoji reactions to any message in your workspace
• File Uploads: Share files with channels including titles and initial comments
• Conversation Browsing: Access all types of conversations including public channels, private channels, group messages, and direct messages
• Message Retrieval: Fetch message history from any accessible channel
• Resource Templates: Access structured information about channels, messages, threads, files, and workspace details through URI-based resources

Tools

send_message

Send a message to a Slack channel or user. This tool supports both new messages and threaded replies, allowing you to maintain context in conversations.

Parameters:

• channel_id (required, string): The channel ID or user ID where the message should be sent
• text (required, string): The message content to send
• thread_ts (optional, string): Thread timestamp for replying within an existing thread

list_channels

List all channels that are accessible to the bot. This tool helps you discover available channels and filter them based on your needs.

Parameters:

• limit (optional, number): Maximum number of channels to return in the response
• types (optional, string): Comma-separated channel types to include, such as "public_channel,private_channel"
• exclude_archived (optional, boolean): Set to true to filter out archived channels from results

add_reaction

Add an emoji reaction to any message in your workspace. Perfect for acknowledging messages or providing quick feedback.

Parameters:

• channel_id (required, string): The channel containing the target message
• timestamp (required, string): The timestamp of the message to react to
• reaction (required, string): The emoji name without colons, for example "thumbsup" or "heart"

upload_file

Upload files to one or more Slack channels. Files can be shared with multiple channels simultaneously and include optional metadata.

Parameters:

• channels (required, array of strings): Array of channel IDs where the file should be shared
• content (required, string): The file content as a string
• filename (required, string): The name for the uploaded file
• title (optional, string): A descriptive title for the file
• initial_comment (optional, string): A comment to post along with the file

list_messages

Retrieve messages from a specific channel. This tool provides access to channel history for analysis, search, or archival purposes.

Parameters:

• channel_id (required, string): The channel ID to fetch messages from

list_conversations

List all conversations accessible to the bot, including channels, direct messages, and group conversations. This provides a comprehensive view of all communication spaces.

Parameters:

• limit (optional, number): Maximum number of conversations to return
• types (optional, string): Conversation types to include, such as "public_channel,private_channel,mpim,im"

Resource Templates

Channel Information

URI Pattern: slack://channel/{channel_id}

Access detailed information about a specific Slack channel, including its name, topic, purpose, member count, and settings. Useful for understanding channel configuration and membership.

Channel Messages

URI Pattern: slack://channel/{channel_id}/messages

Retrieve recent messages from a specific channel. This resource provides a quick way to access channel history and stay updated on conversations.

Channel Members

URI Pattern: slack://channel/{channel_id}/members

Get a complete list of all members in a specific channel. Helpful for understanding who has access to particular conversations and managing team communication.

Message Information

URI Pattern: slack://message/{channel_id}/{timestamp}

Access detailed information about a specific message, including its content, author, reactions, and metadata. Essential for analyzing individual messages and their context.

Thread Replies

URI Pattern: slack://thread/{channel_id}/{thread_ts}

Retrieve all replies within a message thread. This resource makes it easy to follow threaded conversations and understand the complete discussion context.

Workspace Information

URI Pattern: slack://workspace/info

Get information about the current Slack workspace, including its name, domain, and configuration. Useful for understanding workspace settings and capabilities.

File Information

URI Pattern: slack://file/{file_id}

Access information about a specific uploaded file, including its name, type, size, and sharing details. Perfect for tracking and managing shared files.

Use Cases

The Slack MCP Server enables a wide range of automation and integration scenarios:

• Automated Notifications: Send alerts and updates to relevant channels based on external events or triggers
• Message Analysis: Retrieve and analyze message history for insights, compliance, or knowledge management
• Workflow Integration: Connect Slack with other tools and services through AI-powered assistants
• Team Coordination: Automate routine communications and reactions to streamline team workflows
• File Management: Programmatically share documents, reports, and other files with appropriate channels
• Channel Discovery: Dynamically find and interact with channels based on your automation needs

Getting Started

Once configured, the Slack MCP Server provides immediate access to your workspace through any MCP-compatible client. The tools and resources are self-documenting, making it easy to explore capabilities and build powerful integrations. Whether you're automating simple notifications or building complex workflow systems, this server provides the foundation for seamless Slack integration.