Slack MCP Server with SSE Transport

What is Slack MCP Server with SSE Transport?

Slack MCP Server with SSE Transport is a Model Context Protocol (MCP) server that integrates Slack API functionality using Server-Sent Events (SSE) transport instead of stdio. It allows AI assistants to interact with Slack workspaces through a simple HTTP-based interface. The server is built with TypeScript, supports Docker deployment, and works with any MCP client that supports SSE transport.

How to use Slack MCP Server with SSE Transport?

Set environment variables SLACK_BOT_TOKEN (Slack Bot User OAuth Token starting with xoxb-) and SLACK_TEAM_ID (Slack Workspace/Team ID). Build TypeScript code with npm run build and start the server with npm start. Alternatively, deploy with Docker Compose or run a pre-built Docker image. Connect to the SSE endpoint at /sse using an EventSource client.

Key features of Slack MCP Server with SSE Transport

• Uses SSE transport for HTTP/HTTPS communication
• Provides access to essential Slack API functionality
• Includes a simple web UI and health check endpoint
• Fully containerized with Docker for easy deployment
• Built with TypeScript for type safety
• Works with any MCP client supporting SSE transport

Use cases of Slack MCP Server with SSE Transport

• Enable AI assistants to list and post messages in Slack channels
• Let AI assistants reply to threads and add reactions
• Allow AI assistants to retrieve channel history and thread replies
• Enable AI assistants to list users and fetch user profiles
• Integrate Slack collaboration into MCP-based agent workflows

FAQ from Slack MCP Server with SSE Transport

What is the difference between SSE transport and stdio transport?

SSE transport enables communication over HTTP/HTTPS, making the server accessible over the network rather than requiring a direct subprocess connection.

What are the runtime requirements?

Node.js 18 or higher is required. A Slack Bot Token with appropriate scopes and a Slack Team ID are also needed.

Where does user data live?

The server itself does not store data; it makes API calls to Slack on behalf of the token. All data resides in the Slack workspace.

What transports does the server support?

The server exclusively uses Server-Sent Events (SSE) transport. It exposes an SSE endpoint at /sse and does not support stdio.

How do I authenticate with Slack?

Provide the SLACK_BOT_TOKEN (starting with xoxb-) and SLACK_TEAM_ID as environment variables. The token must have scopes like channels:history, channels:read, chat:write, reactions:write, and users:read.