Slack

What it is

Slack MCP Server is an MCP server for the Slack API that enables Claude to interact with Slack workspaces. It exposes eight tools covering channel listing, posting messages, threaded replies, emoji reactions, channel history, thread replies, and user lookups. It runs via NPX (@modelcontextprotocol/server-slack) or Docker (mcp/slack) and authenticates with a Slack bot token.

Who it's for

• Developers who want Claude to read and post messages in a Slack workspace
• Teams configuring Slack access in Claude Desktop or VS Code through MCP
• Admins who need to limit the channels an assistant can access

Requirements

Setup

1. Create the Slack App

   Visit the Slack Apps page (https://api.slack.com/apps), click "Create New App", choose "From scratch", then name your app and select your workspace.

2. Add Bot Token Scopes and install

   Under "OAuth & Permissions", add the scopes channels:history, channels:read, chat:write, reactions:write, users:read and users.profile:read. Then click "Install to Workspace", authorize the app, and save the Bot User OAuth Token starting with xoxb-. Also get your Team ID (starts with T).

3. Configure Claude Desktop (NPX)

   Add this to your claude_desktop_config.json. SLACK_CHANNEL_IDS is optional; if not set, all public channels will be listed.

   jsonCopy

   {
     "mcpServers": {
       "slack": {
         "command": "npx",
         "args": [
           "-y",
           "@modelcontextprotocol/server-slack"
         ],
         "env": {
           "SLACK_BOT_TOKEN": "xoxb-your-bot-token",
           "SLACK_TEAM_ID": "T01234567",
           "SLACK_CHANNEL_IDS": "C01234567, C76543210"
         }
       }
     }
   }

4. Configure Claude Desktop (Docker)

   Alternatively, run the server through Docker using the mcp/slack image.

   jsonCopy

   {
     "mcpServers": {
       "slack": {
         "command": "docker",
         "args": [
           "run",
           "-i",
           "--rm",
           "-e",
           "SLACK_BOT_TOKEN",
           "-e",
           "SLACK_TEAM_ID",
           "-e",
           "SLACK_CHANNEL_IDS",
           "mcp/slack"
         ],
         "env": {
           "SLACK_BOT_TOKEN": "xoxb-your-bot-token",
           "SLACK_TEAM_ID": "T01234567",
           "SLACK_CHANNEL_IDS": "C01234567, C76543210"
         }
       }
     }
   }

5. Build the Docker image locally

   If you want to build the image yourself, use the documented Docker build command.

   bashCopy

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

Examples

{
  "mcp": {
    "inputs": [
      {
        "type": "promptString",
        "id": "slack_bot_token",
        "description": "Slack Bot Token (starts with xoxb-)",
        "password": true
      },
      {
        "type": "promptString",
        "id": "slack_team_id",
        "description": "Slack Team ID (starts with T)"
      }
    ],
    "servers": {
      "slack": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-slack"],
        "env": {
          "SLACK_BOT_TOKEN": "${input:slack_bot_token}",
          "SLACK_TEAM_ID": "${input:slack_team_id}"
        }
      }
    }
  }
}

Post a message to the channel with channel_id C01234567 using slack_post_message, with text "Hello team".

Reply to the thread whose parent message has thread_ts <timestamp> in channel <channel_id> using slack_reply_to_thread.

Use slack_get_channel_history for channel <channel_id> with limit 10 to show recent messages.

Pros & cons

Images