Slack MCP Server

A Model Context Protocol (MCP) server implementation for interacting with the Slack API. This server provides tools for Slack workspace automation.

Features

• Post text messages to Slack channels
• Reply to threads
• Add reactions
• List channels and users
• Fetch channel history and thread replies

Installation

Local Development

1. Clone the repository and install dependencies:

npm install

1. Create a .env file with your Slack credentials:

SLACK_BOT_TOKEN=your_bot_token
SLACK_TEAM_ID=your_team_id

1. Build the project:

npm run build

1. Run the server:

node build/index.js

Available Tools

User Tools

get_users_on_slack

• Description: Get a list of all users in the workspace with their basic profile information.
• Input: json { "limit": 100, "cursor": "optional_cursor" }

get_user_profile_on_slack

• Description: Get detailed profile information for a specific user.
• Input: json { "user_id": "your_user_id" }

Message Tools

send_message_on_slack

• Description: Post a new message to a Slack channel.
• Input: json { "channel_id": "your_channel_id", "text": "Hello, world!" }

Thread Tools

reply_to_thread_on_slack

• Description: Reply to a specific message thread in Slack.
• Input: json { "channel_id": "your_channel_id", "thread_ts": "your_thread_ts", "text": "This is a reply" }

get_thread_replies_on_slack

• Description: Get all replies in a message thread.
• Input: json { "channel_id": "your_channel_id", "thread_ts": "your_thread_ts" }

Channel Tools

channels_list_on_slack

• Description: List public channels in the workspace with pagination.
• Input: json { "limit": 100, "cursor": "optional_cursor" }

get_channel_history_on_slack

• Description: Get recent messages from a channel.
• Input: json { "channel_id": "your_channel_id", "limit": 10 }

Reaction Tools

slack_add_reaction

• Description: Add a reaction emoji to a message.
• Input: json { "channel_id": "your_channel_id", "timestamp": "your_message_ts", "reaction": "your_reaction" }

Usage Example

To call a tool, send a JSON request like this:

{
  "method": "tools/call",
  "params": {
    "name": "send_message_on_slack",
    "arguments": {
      "channel_id": "your_channel_id",
      "text": "Hello from the Slack MCP server!"
    }
  }
}

Environment Variables

Create a .env file with:

SLACK_BOT_TOKEN=your_bot_token
SLACK_TEAM_ID=your_team_id

Running the Server

npm install
npm run build
npx @modelcontextprotocol/slack-server

Or, for direct node execution:

node build/index.js

License

MIT License. See LICENSE for details.