Slack MCP Server

A Model Context Protocol (MCP) server for searching Slack channels and messages.

Features

• list_channels - List available Slack channels in the workspace
• search_messages - Search for messages across channels using text matching
• get_channel_history - Get message history from a specific channel

Installation

Using npx (Recommended)

No installation required. Add directly to your config:

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["-y", "github:nikhilchintawar/slack-mcp"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token-here"
      }
    }
  }
}

Claude Code (~/.claude/settings.json):

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["-y", "github:nikhilchintawar/slack-mcp"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token-here"
      }
    }
  }
}

Manual Installation

# Clone the repository
git clone https://github.com/nikhilchintawar/slack-mcp.git
cd slack-mcp

# Install dependencies
npm install

# Build
npm run build

Then add to your config:

{
  "mcpServers": {
    "slack": {
      "command": "node",
      "args": ["/absolute/path/to/slack-mcp/build/index.js"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token-here"
      }
    }
  }
}

Configuration

Config File Locations

• Claude Desktop (macOS): ~/Library/Application Support/Claude/claude_desktop_config.json
• Claude Desktop (Windows): %APPDATA%\Claude\claude_desktop_config.json
• Claude Code: ~/.claude/settings.json

Environment Variables

Variable	Required	Description
SLACK_BOT_TOKEN	Yes	Slack Bot User OAuth Token
SLACK_CHANNELS	No	Comma-separated list of allowed channels (restricts searches)
SLACK_DEFAULT_CHANNEL	No	Default channel ID for operations

Channel Restrictions

Use SLACK_CHANNELS to restrict which channels can be searched. When configured:

• Searches without a channel specified will search all allowed channels
• Searches with a specific channel will validate it's in the allowed list
• get_channel_history will only work with allowed channels

{
  "env": {
    "SLACK_BOT_TOKEN": "xoxb-your-token",
    "SLACK_CHANNELS": "general,engineering,support"
  }
}

Slack App Setup

1. Create a Slack App at https://api.slack.com/apps
2. Go to "OAuth & Permissions"
3. Add the following Bot Token Scopes:
   • channels:read - List public channels
   • channels:history - Read messages from public channels
   • groups:read - List private channels (optional)
   • groups:history - Read messages from private channels (optional)
4. Install the app to your workspace
5. Copy the "Bot User OAuth Token" (starts with xoxb-)
6. Important: Add the bot to each channel you want to search (right-click channel → "Open channel details" → "Integrations" → "Add apps")

Usage Examples

Once configured, you can use natural language to interact with Slack:

• "List all channels in my Slack workspace"
• "Search for messages about deployment in #engineering"
• "Show me the last 50 messages from #general"
• "Find messages from @john about the API"
• "Search for error messages from last week"

Available Tools

list_channels

List available Slack channels in the workspace.

Parameter	Required	Description
includePrivate	No	Include private channels (default: false)
includeArchived	No	Include archived channels (default: false)
limit	No	Max results (default: 100, max: 1000)

search_messages

Search for messages across Slack channels using text matching. Fetches channel history and filters by query.

Parameter	Required	Description
query	Yes	Search text (case-insensitive). Use | for OR, spaces for AND
channel	No	Channel ID or name. If not set, searches all SLACK_CHANNELS
after	No	Search messages after date (YYYY-MM-DD or ISO 8601)
before	No	Search messages before date (YYYY-MM-DD or ISO 8601)
limit	No	Max results (default: 20, max: 100)

Query examples:

• error - messages containing "error"
• error warning - messages containing both "error" AND "warning"
• error | warning - messages containing "error" OR "warning"

get_channel_history

Get message history from a specific Slack channel.

Parameter	Required	Description
channel	No	Channel ID (uses env var default)
oldest	No	Start time (Unix timestamp or ISO date)
latest	No	End time (Unix timestamp or ISO date)
limit	No	Max results (default: 100, max: 1000)
includeThreadReplies	No	Include thread replies (default: false)

Development

# Watch mode for development
npm run dev

# Build for production
npm run build

# Test with MCP Inspector
SLACK_BOT_TOKEN=xoxb-your-token \
  npx @modelcontextprotocol/inspector node build/index.js

License

MIT