Slack MCP Server

<!-- mcp-name: io.github.stevenvo/slack-mcp-server -->

A Model Context Protocol (MCP) server that provides programmatic access to Slack conversations, threads, and workspace information. Designed for AI assistants like Claude to interact with your Slack workspace through a standardized interface.

What is MCP?

The Model Context Protocol is an open standard that enables AI assistants to securely access external data sources and tools. This server implements MCP to give Claude direct access to your Slack workspace.

Features

📨 Message Operations

• Read Channel Messages: Fetch recent messages from any channel with flexible time-based filtering
• Read Thread Messages: Access complete conversation threads including all replies
• Get Message Permalinks: Generate permanent, shareable links to specific messages

🔍 Discovery & Search

• List Your Channels: Enumerate all channels you're a member of (public, private, DMs, group DMs)
• Search Conversations: Find messages where you're mentioned or involved using Slack's search

📊 Metadata & Context

• Get Channel Info: View channel details, topics, purposes, member counts, and settings
• Get User Info: Look up user profiles, emails, titles, timezones, and status information

Quick Start

Option 1: Install from PyPI (Recommended)

The easiest way to use this MCP server is to install it directly from PyPI:

# Install via pip
pip install slack-mcp-server-v2

# Or install via uvx (recommended for MCP servers)
uvx slack-mcp-server-v2

Option 2: Install from Source

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

# Install dependencies
pip install -r requirements.txt

After installation, you'll need to set up authentication (see below).

Authentication

Option 1: User Token (Recommended)

A User Token uses your personal Slack permissions and can access all channels you're a member of.

1. Go to https://api.slack.com/apps
2. Create a new app (or use existing)
3. Navigate to "OAuth & Permissions"
4. Add the following User Token Scopes:
   • channels:history - View messages in public channels
   • channels:read - View basic channel info
   • groups:history - View messages in private channels
   • groups:read - View basic private channel info
   • im:history - View messages in direct messages
   • im:read - View basic DM info
   • mpim:history - View messages in group DMs
   • mpim:read - View basic group DM info
   • users:read - View user information
   • search:read - Search messages
5. Install the app to your workspace
6. Copy the "User OAuth Token" (starts with xoxp-)

Option 2: Bot Token

A Bot Token is more limited but easier to set up for team-wide access.

1. Follow steps 1-2 above
2. Add Bot Token Scopes instead (same list but in bot section)
3. Install the app
4. Copy the "Bot User OAuth Token" (starts with xoxb-)
5. Invite the bot to channels you want to read: /invite @YourBotName

Configure Environment

Create a .env file:

cp .env.example .env

Edit .env and add your token:

# Use one of these:
SLACK_USER_TOKEN=xoxp-your-user-token-here
# OR
SLACK_BOT_TOKEN=xoxb-your-bot-token-here

Configuration for Claude Code

Add this server to Claude Code by editing your ~/.claude.json file:

Using PyPI Package (Recommended)

{
  "mcpServers": {
    "slack": {
      "command": "uvx",
      "args": ["slack-mcp-server-v2"],
      "env": {
        "SLACK_USER_TOKEN": "xoxp-your-user-token-here",
        "SLACK_WORKSPACE_URL": "https://your-workspace.slack.com"
      }
    }
  }
}

Using Local Installation

If you installed from source:

{
  "mcpServers": {
    "slack": {
      "command": "python",
      "args": ["/path/to/slack-mcp-server/server.py"],
      "env": {
        "SLACK_USER_TOKEN": "xoxp-your-user-token-here",
        "SLACK_WORKSPACE_URL": "https://your-workspace.slack.com"
      }
    }
  }
}

Using Bot Token

If you prefer to use a bot token instead of a user token:

{
  "mcpServers": {
    "slack": {
      "command": "uvx",
      "args": ["slack-mcp-server-v2"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-bot-token-here",
        "SLACK_WORKSPACE_URL": "https://your-workspace.slack.com"
      }
    }
  }
}

Note: Remember to invite your bot to channels: /invite @YourBotName

Verify Installation

Restart Claude Code and verify the server is running:

claude mcp list

You should see slack in the list of active MCP servers.

Available Tools

This server provides 7 MCP tools for interacting with Slack:

📬 read_channel_messages

Retrieve recent messages from any Slack channel with flexible time filtering.

Parameters:

Name	Type	Required	Default	Description
channel_id	string	✅	-	Slack channel ID (e.g., C1234567890)
lookback_hours	number	❌	24	Hours to look back from now
limit	number	❌	100	Max messages to retrieve (max: 1000)

Natural Language Examples:

• "Show me messages from the #general channel in the last 24 hours"
• "Read the last 48 hours of messages from channel C1234567890"
• "Get the most recent 50 messages from C070PDRHQS1"

Returns: Formatted messages with timestamps, user mentions, thread indicators, reactions, and permalinks.

---

💬 read_thread_messages

Read all messages in a conversation thread, including the parent message and all replies.

Parameters:

Name	Type	Required	Description
channel_id	string	✅	Channel ID where the thread exists
thread_ts	string	✅	Thread timestamp (the ts field of the parent message)

Natural Language Examples:

• "Read the full thread with timestamp 1699564800.123456 in channel C1234567890"
• "Show me all replies to message ts 1699564800.123456"

Returns: Complete thread with parent message and all replies, formatted with timestamps and reactions.

---

📋 get_channel_info

Get detailed metadata about a Slack channel.

Parameters:

Name	Type	Required	Description
channel_id	string	✅	Slack channel ID

Natural Language Examples:

• "Get info about channel C1234567890"
• "Show me details for the #engineering channel"

Returns: Channel name, ID, creation date, member count, privacy status, topic, and purpose.

---

👤 get_user_info

Look up detailed profile information for any Slack user.

Parameters:

Name	Type	Required	Description
user_id	string	✅	Slack user ID (e.g., U1234567)

Natural Language Examples:

• "Get info about user U1234567"
• "Show me details for @john.doe"

Returns: User's real name, display name, email, title, status, timezone, and admin/bot flags.

---

📑 list_my_channels

List all channels you're a member of, with support for different channel types.

Parameters:

Name	Type	Required	Default	Description
types	string	❌	public_channel,private_channel	Comma-separated channel types

Supported Types:

• public_channel - Public channels
• private_channel - Private channels
• mpim - Group direct messages
• im - Direct messages

Natural Language Examples:

• "List all my channels"
• "Show me all private channels I'm in"
• "List all my DMs"

Returns: Channel names, IDs, member counts, and privacy indicators.

---

🔍 search_my_conversations

Search for messages across all conversations where you're mentioned or involved.

Parameters:

Name	Type	Required	Default	Description
query	string	✅	-	Search terms
count	number	❌	20	Number of results (max: 100)

Natural Language Examples:

• "Search my conversations for 'deployment'"
• "Find messages mentioning 'bug fix' in the last week"
• "Search for messages about 'Q4 planning'"

Returns: Matching messages with channel names, user info, timestamps, and permalinks.

---

🔗 get_message_permalink

Generate a permanent, shareable link to a specific Slack message.

Parameters:

Name	Type	Required	Description
channel_id	string	✅	Channel ID
message_ts	string	✅	Message timestamp

Natural Language Examples:

• "Get permalink for message 1699564800.123456 in channel C1234567890"
• "Generate a link to this message"

Returns: Permanent URL that works even if the workspace's URL changes.

Usage Examples

Once configured in Claude Code, you can interact with your Slack workspace using natural language. Here are some example queries:

Reading Messages

👤 "Show me the latest messages from #engineering"
🤖 [Claude fetches and displays recent messages with timestamps, users, and links]

👤 "What were the last 100 messages in the #product-updates channel from the past week?"
🤖 [Claude retrieves messages from the last 168 hours with limit of 100]

Following Threads

👤 "Read the full thread that starts at timestamp 1699564800.123456 in channel C1234567890"
🤖 [Claude displays the entire conversation thread with all replies]

Discovery & Search

👤 "List all channels I'm a member of"
🤖 [Claude shows all your public and private channels with member counts]

👤 "Search my Slack conversations for 'quarterly review'"
🤖 [Claude searches across all your messages and shows matches with context]

👤 "Find mentions of 'production deployment' in my conversations"
🤖 [Claude uses Slack search to find relevant messages]

Getting Context

👤 "Get info about channel C1234567890"
🤖 [Claude shows channel name, topic, member count, etc.]

👤 "Who is user U1234567?"
🤖 [Claude displays user profile with email, title, timezone]

👤 "Get me a permanent link to message 1699564800.123456 in #general"
🤖 [Claude generates a shareable permalink]

Practical Workflows

Catch up on a project:

👤 "Show me all messages from #project-alpha in the last 3 days"

Find that important decision:

👤 "Search for messages about 'API migration decision'"

Get onboarding context:

👤 "List all channels I'm in and show me the purpose of each"

Finding Channel IDs

Method 1: From Slack URL

When you're in a channel, the URL looks like:

https://your-workspace.slack.com/archives/C1234567890/p1234567890

The part after /archives/ is the channel ID: C1234567890

Method 2: Using the MCP Server

Ask Claude:

List all my channels

Method 3: Right-click in Slack

1. Right-click on the channel name
2. Click "Copy link"
3. Extract the channel ID from the URL

Requirements

• Python: 3.10 or higher
• Slack Workspace: Admin access to create and configure a Slack app
• Claude Code: Latest version with MCP support
• Operating System: macOS, Linux, or Windows with WSL

Troubleshooting

"Missing required scopes" Error

Your Slack app needs the proper OAuth scopes configured.

Solution:

1. Go to https://api.slack.com/apps and select your app
2. Navigate to "OAuth & Permissions"
3. Ensure you've added all required scopes listed in the Authentication section
4. Reinstall the app to your workspace
5. Copy the new token

"Channel not found" Error

For Bot Tokens:

# Invite the bot to the channel first
/invite @YourBotName

For User Tokens:

• Verify you're a member of the channel
• Check the channel ID is correct (see "Finding Channel IDs" section)

"Not authenticated" Error

Check your configuration:

# Verify token is set correctly (check ~/.claude.json)
cat ~/.claude.json | grep -A 5 "slack"

# Ensure no extra whitespace
echo "$SLACK_USER_TOKEN" | wc -c

Common issues:

• Token has expired or been revoked
• Extra spaces or newlines in the token string
• Wrong token type (user vs bot)
• Token not properly quoted in JSON

MCP Server Not Running

Verify server is loaded:

# List all MCP servers
claude mcp list

# Check if slack server is running
claude mcp list | grep slack

Check logs for errors:

# View recent MCP server logs
tail -f ~/.claude/debug/*.log

# Filter for slack-related errors
tail -f ~/.claude/debug/*.log | grep -i slack

Common solutions:

1. Restart Claude Code completely
2. Check ~/.claude.json syntax is valid JSON
3. Verify Python version: python --version (must be 3.10+)
4. Test the server manually: python server.py (if installed from source)

SSL Certificate Errors

If you're behind a corporate proxy (like Zscaler):

# Set SSL certificate environment variable
export SSL_CERT_FILE=/path/to/your/ca-bundle.pem
export REQUESTS_CA_BUNDLE=/path/to/your/ca-bundle.pem

# Then reinstall
pip install slack-mcp-server-v2

Rate Limiting

Slack API has rate limits. If you hit them:

• Reduce the limit parameter in read_channel_messages
• Increase lookback_hours to fetch fewer messages
• Wait a few minutes before retrying

Rate limit indicators:

Error: ratelimited

Solution: The server will automatically handle rate limits, but you may need to wait.

Security & Privacy

Token Security

• Never commit tokens to version control - The .env file is gitignored by default
• Revoke compromised tokens immediately at https://api.slack.com/apps
• Use environment variables in production, never hardcode tokens
• Rotate tokens periodically as part of security best practices

Data Access

User Tokens:

• Have access to everything you can see in Slack
• Use your personal permissions
• See all channels you're a member of
• More convenient for personal use

Bot Tokens:

• Limited to channels where the bot is invited
• Separate from personal identity
• Better for team/shared setups
• More granular control

Corporate Environments

If you're using this in a corporate environment:

• Check with your IT/Security team before creating Slack apps
• Be aware of data retention and compliance policies
• Consider using bot tokens for audit trails
• SSL certificate configuration may be required (see Troubleshooting)

Limitations

• Read-only: This server only reads data, it cannot post messages or modify content
• Rate limits: Subject to Slack's API rate limits (Tier 3: ~50 requests per minute)
• Token scope: Can only access channels/conversations the token has permission to see
• Message history: Limited to Slack workspace's message retention policy

Contributing

Contributions are welcome! Here's how you can help:

Reporting Issues

Found a bug or have a feature request?

1. Check existing issues at https://github.com/stevenvo/slack-mcp-server/issues
2. Create a new issue with:
   • Clear description of the problem/feature
   • Steps to reproduce (for bugs)
   • Expected vs actual behavior
   • Your environment (Python version, OS, Claude Code version)

Pull Requests

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Make your changes
4. Test thoroughly
5. Commit with clear messages: git commit -m "Add amazing feature"
6. Push to your fork: git push origin feature/amazing-feature
7. Open a Pull Request

Development Setup

# Clone your fork
git clone https://github.com/YOUR_USERNAME/slack-mcp-server.git
cd slack-mcp-server

# Install in development mode
pip install -e .

# Make changes and test
python server.py

Changelog

v0.1.0 (2025-01-06)

• Initial release
• 7 core tools for reading Slack conversations
• Support for user and bot tokens
• Published to PyPI and MCP registry
• Comprehensive documentation

Roadmap

Potential future enhancements:

• [ ] Support for Slack Enterprise Grid
• [ ] Message filtering by user or reactions
• [ ] Export conversations to different formats
• [ ] Support for Slack Connect channels
• [ ] Caching to reduce API calls
• [ ] Webhook support for real-time updates

Suggestions welcome in GitHub Issues!

Related Projects

• Model Context Protocol - The MCP specification
• MCP Registry - Browse more MCP servers
• Slack SDK for Python - The underlying library
• Claude Code - AI assistant with MCP support

Support

• Documentation: You're reading it!
• Issues: https://github.com/stevenvo/slack-mcp-server/issues
• Discussions: https://github.com/stevenvo/slack-mcp-server/discussions
• Slack API Docs: https://api.slack.com/docs

License

MIT License - see LICENSE file for details.

Copyright (c) 2025 Steven Vo

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