slack user mcp

MCP Server for the Slack API, enabling Claude to interact with Slack workspaces as a user.

Tools

1. slack_list_channels
2. List public channels in the workspace
3. Optional inputs:
   • limit (number, default: 100, max: 200): Maximum number of channels to return
   • cursor (string): Pagination cursor for next page

4. Returns: List of channels with their IDs and information

5. slack_post_message

6. Post a new message to a Slack channel
7. Required inputs:
   • channel_id (string): The ID of the channel to post to
   • text (string): The message text to post

8. Returns: Message posting confirmation and timestamp

9. slack_reply_to_thread

10. Reply to a specific message thread
11. Required inputs:
    • channel_id (string): The channel containing the thread
    • thread_ts (string): Timestamp of the parent message
    • text (string): The reply text

12. Returns: Reply confirmation and timestamp

13. slack_add_reaction

14. Add an emoji reaction to a message
15. Required inputs:
    • channel_id (string): The channel containing the message
    • timestamp (string): Message timestamp to react to
    • reaction (string): Emoji name without colons

16. Returns: Reaction confirmation

17. slack_get_channel_history

18. Get recent messages from a channel
19. Required inputs:
    • channel_id (string): The channel ID
20. Optional inputs:
    • limit (number, default: 10): Number of messages to retrieve

21. Returns: List of messages with their content and metadata

22. slack_get_thread_replies

23. Get all replies in a message thread
24. Required inputs:
    • channel_id (string): The channel containing the thread
    • thread_ts (string): Timestamp of the parent message

25. Returns: List of replies with their content and metadata

26. slack_get_users

27. Get list of workspace users with basic profile information
28. Optional inputs:
    • cursor (string): Pagination cursor for next page
    • limit (number, default: 100, max: 200): Maximum users to return

29. Returns: List of users with their basic profiles

30. slack_get_user_profile

31. Get detailed profile information for a specific user
32. Required inputs:
    • user_id (string): The User is ID
33. Returns: Detailed user profile information

Setup

1. Create a Slack App:
2. Visit the Slack Apps page
3. Click "Create New App"
4. Choose "From scratch"

5. Name your app and select your workspace

6. Configure User Token Scopes: Navigate to "OAuth & Permissions" and add these scopes:

7. channels:history - View messages and other content in public channels
8. channels:read - View basic channel information
9. chat:write - Send messages as yourself
10. reactions:write - Add emoji reactions to messages

11. users:read - View users and their basic information

12. Install App to Workspace:

13. Click "Install to Workspace" and authorize the app

14. Save the "User OAuth Token" that starts with xoxp-

15. Get your Team ID (starts with a T) by following this guidance

Usage with Claude Desktop

Add the following to your claude_desktop_config.json:

Local Installation

First install and build the server:

git clone https://github.com/lars-hagen/slack-user-mcp.git
cd slack-user-mcp
npm install
npm run build

Then configure Claude Desktop:

{
  "mcpServers": {
    "slack": {
      "command": "npm",
      "args": [
        "run",
        "--prefix",
        "/path/to/slack-user-mcp",
        "start"
      ],
      "env": {
        "SLACK_TOKEN": "xoxp-your-user-token",
        "SLACK_TEAM_ID": "T01234567"
      }
    }
  }
}

NPX

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-slack-user"
      ],
      "env": {
        "SLACK_TOKEN": "xoxp-your-user-token",
        "SLACK_TEAM_ID": "T01234567"
      }
    }
  }
}

Docker

{
  "mcpServers": {
    "slack": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "SLACK_TOKEN",
        "-e",
        "SLACK_TEAM_ID",
        "mcp/slack-user"
      ],
      "env": {
        "SLACK_TOKEN": "xoxp-your-user-token",
        "SLACK_TEAM_ID": "T01234567"
      }
    }
  }
}

Installing via Smithery

To install Slack User Server for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @lars-hagen/slack-user-mcp2 --client claude

Troubleshooting

If you encounter permission errors, verify that: 1. All required scopes are added to your Slack app 2. The app is properly installed to your workspace 3. The tokens and workspace ID are correctly copied to your configuration 4. The app has been added to the channels it needs to access 5. You're using a User OAuth Token (starts with xoxp-) not a Bot Token

Build

Docker build:

docker build -t mcp/slack-user -f src/slack/Dockerfile .

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.