Slack MCP Server

A Model Context Protocol (MCP) server that provides seamless Slack integration for AI assistants. This server enables AI models to interact with Slack workspaces through a comprehensive set of tools for messaging, channel management, and user interactions.

Features

Core Slack Tools

• Message Management: Send messages to channels and users
• Channel Operations: List channels and retrieve message history
• User Management: Get workspace user information
• Message Search: Search across workspace messages
• Custom Tools: Specialized tools for specific workflows

Special Features

• Smart Workday Calculation: Automatically reads messages from the previous workday
• User-Specific Filtering: Dedicated tool for reading specific user messages
• Rich Message Information: Includes user details, timestamps, and thread information
• Flexible Time Ranges: Support for custom date ranges and all-time searches

Available Tools

Installation

Prerequisites

• Node.js 18 or higher
• npm or yarn
• Slack Bot Token with appropriate permissions

Setup

1. Clone and install dependencies:

   git clone <repository-url>
   cd slack-mcp
   npm install
   

2. Build the project:

   npm run build
   

Configuration

Environment Variables

Create a .env file with the following:

# Required: Slack Bot Token from https://api.slack.com/apps

Slack Bot Permissions

Your Slack Bot needs the following OAuth scopes:

Required Scopes

• channels:read - Read public channels
• channels:history - Read channel message history
• groups:read - Read private channels
• groups:history - Read private channel history
• users:read - Read user information
• chat:write - Send messages
• search:read - Search messages

Optional Scopes

• channels:manage - Create channels (if using channel creation tools)
• groups:write - Manage private channels

MCP Configuration

Add to your MCP client configuration (e.g., Cursor's mcp.json):

{
  "mcpServers": {
    "slack-mcp": {
      "command": "node",
      "args": [
        "YOUR_PATH/slack-mcp/dist/index.js",
        "--token",
        "YOUR TOKEN",
        "--user-id",
        "YOUR PERSONAL SLACK ID"
      ]
    }
  }
}

Usage Examples

Basic Message Sending

// Send a message to a channel
{
  "tool": "slack_send_message",
  "parameters": {
    "channel": "general",
    "text": "Hello from MCP!"
  }
}

// Send a direct message to a user
{
  "tool": "slack_send_message",
  "parameters": {
    "channel": "U1234567890",
    "text": "Private message"
  }
}

Reading Channel History

// Get recent messages from a channel
{
  "tool": "slack_get_channel_history",
  "parameters": {
    "channel": "frontend-ladisai",
    "limit": 10
  }
}

Special: Reading Neil Kuo's Messages

// Get Neil Kuo's latest messages (automatic workday detection)
{
  "tool": "read_frontend_ladisai_messages",
  "parameters": {
    "max_results": 5
  }
}

// Get all-time latest messages
{
  "tool": "read_frontend_ladisai_messages",
  "parameters": {
    "all_time": true,
    "max_results": 10
  }
}

// Get messages from a specific date
{
  "tool": "read_frontend_ladisai_messages",
  "parameters": {
    "manual_date": "2025-01-27",
    "max_results": 5
  }
}

User and Channel Information

// List all users
{
  "tool": "slack_get_users",
  "parameters": {
    "limit": 100
  }
}

// List all channels
{
  "tool": "slack_get_channels",
  "parameters": {
    "exclude_archived": true
  }
}

Development

Scripts

• npm run build - Build the TypeScript project
• npm run dev - Build and watch for changes
• npm start - Start the MCP server
• npm run typecheck - Run TypeScript type checking

Project Structure

slack-mcp/
 src/
    index.ts              # Main MCP server
    slack-client.ts       # Slack API client wrapper
    tools/
        index.ts          # Tool registry
        send-message.ts   # Message sending tool
        get-channels.ts   # Channel listing tool
        get-users.ts      # User listing tool
        get-channel-history.ts  # Channel history tool
        search-messages.ts      # Message search tool
        read-frontend-ladisai.ts # Custom Neil Kuo reader
 dist/                     # Compiled JavaScript
 package.json
 README.md

Smart Workday Logic

The read_frontend_ladisai_messages tool includes intelligent workday calculation:

• Monday Reads Friday's messages (3 days back)
• Tuesday Reads Monday's messages (1 day back)
• Wednesday Reads Tuesday's messages (1 day back)
• Thursday Reads Wednesday's messages (1 day back)
• Friday Reads Thursday's messages (1 day back)
• Saturday Reads Friday's messages (1 day back)
• Sunday Reads Friday's messages (2 days back)

Troubleshooting

Common Issues

1. "Failed to get channel list"

   • Check if your bot has channels:read permission
   • Ensure the bot is added to the workspace

2. "Failed to get channel history"

   • Verify the bot has channels:history permission
   • Check if the bot is invited to the specific channel

3. "Message sent successfully" but no message appears

   • Confirm the bot has chat:write permission
   • Verify the channel name/ID is correct

4. MCP server not responding

   • Check if the build was successful: npm run build
   • Verify environment variables are set correctly
   • Restart your MCP client (e.g., Cursor)

Testing the Server

# Test if the server responds to tool list requests
echo '{"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}}' | node dist/index.js

License

MIT License - see LICENSE file for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Support

For issues and questions:

• Check the troubleshooting section above
• Review Slack API documentation
• Check MCP protocol specifications

Note: This MCP server is optimized for the frontend-ladisai channel workflow and includes specialized tools for reading Neil Kuo's messages with smart workday detection.