What it does
Provides programmatic access to Slack workspaces via the Model Context Protocol, letting Claude read channel messages, thread history, direct messages, and search across a workspace's message archive. Supports multiple transport protocols (Stdio, SSE, HTTP), works with both OAuth and stealth mode (requiring no bot approvals), and includes smart history pagination, unread message filtering, and user information embedding for context.
Who it's for
Developers and teams building AI applications that need to fetch Slack context—particularly those using Claude in workflows where workspace history or real-time message access is relevant. Common users include engineering teams automating Slack-based tasks, platform engineers wiring Claude into Slack integrations, and operators needing scriptable access to workspace data.
Common use cases
- Provide Claude with recent channel messages as context before generating responses
- Search workspace message history for specific topics or discussions
- Fetch unread messages across multiple channels with priority sorting
- Retrieve thread conversations to give Claude full discussion context
- Build Slack automation that uses Claude as a reasoning layer
Setup pitfalls
- Message posting (
conversations_add_message) is disabled by default; enable via theSLACK_MCP_ADD_MESSAGE_TOOLenvironment variable, with optional comma-separated channel ID restrictions. - Workspace access requires either valid OAuth tokens or stealth mode permissions; stealth mode works within existing user permissions but requires no bot approvals.
- Channel references accept multiple formats—ID (
Cxxxxxxxxxx), name (#general), or user (@username_dm)—and incorrect formats cause lookup failures. - Free Slack workspaces have 90-day message history; paid tiers may retain longer—requests for older messages will return empty.