mcp-slack-crunchtools
Secure read-only MCP server for Slack workspaces. Provides Claude Code (and other MCP clients) with access to your Slack channels, messages, users, and files without any write permissions.
Features
- Read-only: 15 tools, all read-only. Never posts, edits, or deletes anything.
- Secure: 6-layer security model (input validation, token handling, client hardening, output sanitization, runtime protection, supply chain security).
- User OAuth Token: Uses
xoxp-tokens for user-scoped access to your workspace. - No SDK dependency: Uses
httpxdirectly for minimal, auditable HTTP calls.
Quick Start
Using uvx (Recommended)
claude mcp add mcp-slack-crunchtools \
--env SLACK_USER_TOKEN=xoxp-your-token \
-- uvx mcp-slack-crunchtools
Using Container
claude mcp add mcp-slack-crunchtools \
--env SLACK_USER_TOKEN=xoxp-your-token \
-- podman run -i --rm -e SLACK_USER_TOKEN quay.io/crunchtools/mcp-slack
Local Development
claude mcp add mcp-slack-crunchtools \
--env SLACK_USER_TOKEN=xoxp-your-token \
-- uv run mcp-slack-crunchtools
Setup
See CLAUDE.md for detailed instructions on creating a Slack app and obtaining a User OAuth Token.
Tools
| Tool | Description |
|---|---|
slack_auth_test | Test connection and get token owner info |
slack_list_channels | List workspace channels |
slack_get_channel_info | Get channel details |
slack_get_channel_history | Read channel messages |
slack_get_thread_replies | Read thread replies |
slack_list_channel_members | List channel members |
slack_search_messages | Search messages |
slack_get_reactions | Get message reactions |
slack_list_reactions | List user's reactions |
slack_list_stars | List starred items |
slack_get_user_info | Get user details |
slack_list_users | List workspace members |
slack_get_user_profile | Get user profile |
slack_list_files | List files (metadata only) |
slack_get_file_info | Get file metadata |
Security
See SECURITY.md for the full security design document.
License
AGPL-3.0-or-later
<!-- mcp-name: io.github.crunchtools/slack -->