Slack MCP Server
A feature-rich MCP server for Slack that enables AI agents to read messages, DMs, group DMs, search channels, manage user groups, and post messages with smart history pagination, supporting both stealth (no-bot) and OAuth modes.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Slack workspace MCP. Bot token with fine-grained OAuth scopes. Bot can read all channels it joins — scope carefully. Signing secret for webhook validation. Treat bot token as secret.
⚡ Reliability
Best When
You want an AI assistant to have deep, read-first access to Slack workspace context — history, DMs, channels — with optional write capability controlled by explicit agent permissions.
Avoid When
You need a traditional Slack bot with event subscriptions, slash commands, and webhook-driven interactions rather than a pull-based MCP interface.
Use Cases
- • Aggregate and summarize unread messages across all Slack channels with priority sorting for AI-assisted triage
- • Search message history with date-range or count-based pagination for AI-powered workspace analytics
- • Enable AI assistants to respond to DMs and group DMs on behalf of users within Claude or other MCP clients
- • Manage Slack user groups (subteams) programmatically — create, update, and manage membership via AI agent
- • Monitor and analyze Slack conversations in FedRAMP-compliant GovSlack workspaces
Not For
- • Fully automated bots that post without human oversight — posting is disabled by default for safety
- • Teams needing Slack workflow builder integration or slash command handling
- • Scenarios requiring compliance-grade audit logging of all AI-Slack interactions
Interface
Authentication
Supports user OAuth tokens (xoxp-), bot tokens (xoxb-), and browser session tokens (xoxc-/xoxd-). SSE/HTTP transport mode requires an API key. GovSlack requires separate FedRAMP-compliant token configuration.
Pricing
MIT open source. Requires an active Slack workspace and valid Slack tokens. Slack API rate limits apply.
Agent Metadata
Known Gotchas
- ⚠ Browser session tokens (xoxc-/xoxd-) extracted from browser are fragile and expire; Slack may invalidate them without warning
- ⚠ Stealth mode using user tokens may violate Slack's Terms of Service in some workspace configurations — legal review advised
- ⚠ Message posting is disabled by default and must be explicitly enabled — agents must handle this configuration
- ⚠ Slack API rate limits (especially for history fetching) can cause tool timeouts on large workspaces
- ⚠ Local user/channel cache can become stale in rapidly growing workspaces without explicit cache refresh
- ⚠ GovSlack configuration requires separate setup not covered in main documentation
Alternatives
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Scores are editorial opinions as of 2026-03-07.