Slack MCP server that enables automated interaction with Slack workspaces via the Model Context Protocol. It supports both stdio and Streamable HTTP transports, and is extended from Anthropic's original, now archived implementation. The server exposes a comprehensive Slack integration layer with tools to list channels, post messages, reply to threads, add reactions, fetch channel history, retrieve thread replies, list users, and fetch user profiles. Built on the MCP SDK v1.13.2, it uses modern APIs and Zod-based validation for request schemas. The transport layer supports session management, RESTful API endpoints for HTTP transport, and optional Bearer token authentication with CLI/token/env var configuration. The project includes a CLI and Docker deployment options, along with detailed Slack bot setup including required OAuth scopes. Configuration is via environment variables (Slack bot token, team ID, predefined channels) and optional AUTH_TOKEN for HTTP transport. Endpoints exposed under the Streamable HTTP transport include POST /mcp (client-to-server), GET /mcp (server-sent events), and DELETE /mcp (terminate session).