How do I install MCP Slack?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does MCP Slack need an API key?

No required environment variable is listed on this record.

What transport does MCP Slack use?

MCP Slack runs locally over stdio.

When was MCP Slack last checked?

Last checked 2026-11-09. Secure read-only MCP server for Slack workspaces

MCP Slack MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

uvx mcp-slack-crunchtools==0.1.2

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1claude mcp add io.github.crunchtools-slack -- uvx mcp-slack-crunchtools==0.1.2

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.crunchtools-slack": {4      "command": "uvx",5      "args": [6        "mcp-slack-crunchtools==0.1.2"7      ]8    }9  }10}

claude_desktop_config.json

Local · pypiPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 0.1.2
Last checked

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

mcp-slack-crunchtools

Secure MCP server for Slack workspaces. Provides Claude Code (and other MCP clients) with read access to your Slack channels, messages, users, and files, and can send a message on your behalf.

Features

Mostly read: 15 of the 17 tools only read and publish readOnlyHint: true. The other two send a message and cancel a scheduled one; nothing edits or deletes existing content.
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 httpx directly 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.

Configuration

Authentication uses one of two mutually exclusive modes. The server picks cookie mode when both cookie variables are set, and token mode otherwise.

Variable	Required	Default	Description
`SLACK_USER_TOKEN`	token mode	—	User OAuth token (`xoxp-...`) from a Slack app installed in the workspace.
`SLACK_COOKIE_TOKEN`	cookie mode	—	Browser session token (`xoxc-...`). Must be paired with `SLACK_COOKIE_D`.
`SLACK_COOKIE_D`	cookie mode	—	Value of the `d` cookie (`xoxd-...`) from the same browser session. Sent as a `Cookie:` header alongside `SLACK_COOKIE_TOKEN`.
`SLACK_ADD_MESSAGE_DELAY`	no	`3m`	How far ahead outgoing messages are scheduled, giving you a window to cancel one. Duration string: `30s`, `5m`, `2h`, or a bare integer for seconds. Set to `0`, `0s`, `none`, or `false` to disable scheduling and post immediately.

Which auth mode to use

Cookie mode is the working path for this deployment. Token mode requires a Slack app to be created and approved in the workspace; where that approval is not available, cookie mode is the only way to authenticate at all.

Cookie mode borrows an existing browser session rather than holding a credential issued to an application. That has consequences worth stating plainly:

Both values are live session credentials. Anything holding them can act as you in Slack, with your full access. Treat them exactly as you would your password.
They expire when the browser session does, so cookie mode needs periodic re-extraction. A sudden wave of auth failures usually means the session rotated, not that the server broke.
Slack does not issue these for programmatic use and can invalidate them at any time. Cookie mode is a workaround for the absence of an approved app, not a supported integration path.

Prefer SLACK_USER_TOKEN whenever a Slack app can actually be installed.

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
`slack_send_message`	Schedule a message `SLACK_ADD_MESSAGE_DELAY` ahead, or post it immediately when the delay is `0` (write)
`slack_cancel_scheduled_message`	Cancel a scheduled message before it sends (write)

The two write tools need the chat:write scope in token mode.

Security

See SECURITY.md for the full security design document.

License

AGPL-3.0-or-later

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install MCP Slack?

Does MCP Slack need an API key?

What transport does MCP Slack use?

When was MCP Slack last checked?

Documentation

mcp-slack-crunchtools

Features

Quick Start

Using uvx (Recommended)

Using Container

Local Development

Setup

Configuration

Which auth mode to use

Tools

Security

License