Slack MCP Server

The Slack MCP server by Dmitrii Korotovskii is a Go-based community project that makes Slack workspaces accessible to AI agents via MCP. It is not an official Slack product - the only previously official reference server is now archived and no longer maintained.

Feature scope

The server supports 18 tools, including retrieving and sending messages, thread replies, reactions, user group management, channel and thread references via #Name and @Lookup, smart history retrieval, and full-text message search.

Three ways to authenticate

A key difference from the classic OAuth app approach: the server accepts bot tokens (xoxb), user OAuth tokens (xoxp), or browser session tokens (xoxc plus xoxd). With the browser-token method, no Slack app creation and no approval by workspace admins is required - though the project itself notes that user or bot tokens are more secure, since they do not depend on an active browser session.

Stdio, SSE, and HTTP transports are supported.

Why a community project instead of an official server

Slack itself does not offer an actively maintained official MCP server; the earlier reference server from the Model Context Protocol project has been archived. For teams that still want to connect Slack to an AI agent, Korotovskii's server is currently the most popular alternative. Important context: without official Slack involvement, there is no guarantee of long-term maintenance or compatibility with future Slack API changes, even though the project is actively developed.

Typical use cases

In practice, the server is useful for having an AI agent automatically respond to questions in specific channels, summarize long threads, forward support requests from a channel into a ticketing system, or post recurring status updates automatically. Because user and browser tokens grant access to private channels and direct messages, the intended scope should be clearly defined in advance.

Frequently asked questions

Is this an official Slack product? No, explicitly not; Slack itself is not involved in this project. Which token type is safest? Per the project documentation, bot or user tokens are preferable since they don't depend on an active browser session. Can the server be used without creating your own Slack app? Yes, via the browser-token method, though at the cost of lower security.

Setup at a glance

For getting started, a single token is usually enough: anyone who only wants to use the server to read and reply to messages in their own bot channel can get by with a bot token and a minimal Slack app without complicated permission management. Anyone who needs full-text search across the whole workspace or access to private channels has to use a user OAuth token instead, accepting the larger security risk of a compromised token. The browser-token method remains more of a stopgap for quick tests when there's no permission to create a Slack app.

Node.js 18 or newer to run via npx, or Docker as an alternative. Also requires at least one valid Slack token (xoxb, xoxp, or xoxc plus xoxd).

Start the server via npx and add it to the client MCP configuration. A Slack token is required before first use (see the "Authentication" field). Alternatively, a Docker image is available at ghcr.io/korotovsky/slack-mcp-server.

npx -y slack-mcp-server@latest --transport stdio

The server accepts four token types via environment variables, at least one is required: SLACK_MCP_XOXB_TOKEN (bot token, must be invited to channels, cannot search messages), SLACK_MCP_XOXP_TOKEN (user OAuth token, full user permissions including search), or SLACK_MCP_XOXC_TOKEN together with SLACK_MCP_XOXD_TOKEN (browser session token, read from developer tools or cookies of your own Slack session). Per the project documentation, user or bot tokens are preferable, as they do not depend on an active browser session.

The feature scope depends on the chosen token type. Bot tokens are limited to channels the bot has been invited to and cannot use Slack search. User OAuth and browser tokens act on behalf of the respective Slack user and carry that user’s full access scope, including private channels and direct messages visible to that user.

The server retrieves messages, channel and user data, and search results via the Slack Web API and forwards them to the MCP client. When using browser tokens, authentication relies on the user’s active Slack browser session rather than a separate app registration.

As a community project unaffiliated with Slack, Slack’s own security documentation does not cover this server. With user OAuth and especially browser tokens, the server acts with that person’s full access scope - a compromised token allows reading and writing in every channel and direct message visible to that person. Browser tokens are extracted manually from developer tools and cookies of your own session; the project itself recommends bot or user tokens as the safer alternative. Tokens should be kept only in environment variables and never committed to version control.