Slack MCP Server

Slack MCP Server

Give your AI agent full Slack access — and structured workflow output the AI can actually use. No app registration, no admin approval, no OAuth. One command, 21 tools, works with any MCP client.

npx -y @jtalk22/slack-mcp --setup

▶ Watch the demo — 7 scenarios, from 47 unreads to inbox zero, without opening Slack.

Ask your AI to catch you up on #engineering from the last 24 hours. Search for that deployment thread from last week. Find the printer admin PIN nobody can remember. Send a reply. All from your editor.

Interactive demo · Latest release

Why This Exists

Slack's official MCP server requires a registered app, admin approval, and doesn't work with Claude Code or GitHub Copilot due to OAuth/DCR incompatibility. Screenshotting messages is not a workflow.

This server uses your browser's session tokens instead. If you can see it in Slack, your AI agent can see it too. No app install, no scopes, no admin.

Session-token transport: No bot user appears in the workspace admin panel, no app install shows up, no audit trail entry is created. Your AI agent operates with the same workspace footprint as your browser tab — nothing more, nothing less.

Workflow Primitives

Introduced in 4.2. Save a workflow profile that binds a workflow_kind to channels + priority people + retention + cadence. Stored locally at ~/.slack-mcp-workflows.json. The hosted brain at mcp.revasserlabs.com reads these profiles and returns structured JSON per workflow_kind — downstream automation (Linear, Notion, status dashboards) consumes the JSON directly.

Six prebuilt templates ship with the package:

npx -y @jtalk22/slack-mcp --apply-template oncall-handoff --channels C012345,C067890

Available templates: oncall-handoff, support-triage, exec-monday, sprint-tracker, customer-feedback, incident-room. The structural primitives (slack_workflow_save, slack_workflows) are free forever in OSS; the hosted brain is $0 to start (no card) and $9/mo Pro for unlimited AI tools (scheduled morning catch-up DM rolling out Q2 2026).

Quick Start per Client

Add to ~/.claude.json or Claude Desktop settings:

{
  "mcpServers": {
    "slack": { "command": "npx", "args": ["-y", "@jtalk22/slack-mcp"] }
  }
}

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "slack": { "command": "npx", "args": ["-y", "@jtalk22/slack-mcp"] }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "slack": { "command": "npx", "args": ["-y", "@jtalk22/slack-mcp"] }
  }
}

Add to ~/.gemini/settings.json:

{
  "mcpServers": {
    "slack": { "command": "npx", "args": ["-y", "@jtalk22/slack-mcp"] }
  }
}

Add to ~/.codex/config.toml:

[mcp_servers.slack]
command = "npx"
args = ["-y", "@jtalk22/slack-mcp"]

Or via CLI: codex mcp add slack -- npx -y @jtalk22/slack-mcp

Tools

21 tools total: 12 read-only Slack, 4 write-path Slack, 2 workflow profile primitives (1 local-write, 1 read-only), 3 hosted stubs. All carry MCP safety annotations.

* slack_refresh_tokens modifies local token file only.

† Hosted stubs return a structured upgrade payload (signup_url, free_tier_quota, pro_value_prop) — no Slack write occurs from OSS. Activate the brain at mcp.revasserlabs.com (free tier, no card).

Install

Node.js 20+

npx -y @jtalk22/slack-mcp --setup

The setup wizard handles token extraction and validation.

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["-y", "@jtalk22/slack-mcp"]
    }
  }
}

Edit %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["-y", "@jtalk22/slack-mcp"],
      "env": {
        "SLACK_TOKEN": "xoxc-your-token",
        "SLACK_COOKIE": "xoxd-your-cookie"
      }
    }
  }
}

Windows/Linux users must provide tokens via env since auto-refresh is macOS-only.

Add to ~/.claude.json:

{
  "mcpServers": {
    "slack": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@jtalk22/slack-mcp"]
    }
  }
}

Any client that supports stdio MCP servers works. Add to your client's MCP config:

{
  "slack": {
    "command": "npx",
    "args": ["-y", "@jtalk22/slack-mcp"],
    "env": {
      "SLACK_TOKEN": "xoxc-your-token",
      "SLACK_COOKIE": "xoxd-your-cookie"
    }
  }
}

On macOS, tokens are auto-extracted from Chrome — env block is optional.

Hosted tiers at mcp.revasserlabs.com:

docker pull ghcr.io/jtalk22/slack-mcp-server:latest

{
  "mcpServers": {
    "slack": {
      "command": "docker",
      "args": ["run", "-i", "--rm",
               "-v", "~/.slack-mcp-tokens.json:/root/.slack-mcp-tokens.json",
               "ghcr.io/jtalk22/slack-mcp-server"]
    }
  }
}

Restart your client after configuration. Full setup: docs/SETUP.md

How It Works

Session tokens (xoxc- + xoxd-) from your browser. If you can see it in Slack, this server can see it too.

Token persistence — four-layer fallback:

1. Environment variables (SLACK_TOKEN, SLACK_COOKIE)
2. Token file (~/.slack-mcp-tokens.json, chmod 600)
3. macOS Keychain (encrypted)
4. Chrome auto-extraction (macOS)

Tokens expire. The server notices before you do — proactive health monitoring, automatic refresh on macOS, warnings when tokens age out. File writes are atomic (temp file → chmod → rename) to prevent corruption. Concurrent refresh attempts are mutex-locked.

• Workflow primitives — slack_workflow_save + slack_workflows bind a workflow_kind (incident_room, exec_brief, support_inbox, product_launch_watch, custom) to channels, priority people, retention, and cadence. The hosted brain returns structured JSON per kind — incident_room returns {incident_summary, timeline, open_risks, owner_gaps, next_actions}, exec_brief returns {summary, decisions, risks, asks, action_items}. Downstream automation (Linear, Notion, dashboards) consumes the JSON directly.
• Discoverable upgrade stubs — slack_smart_search, slack_catch_me_up, slack_triage appear in OSS as upgrade payloads pointing at the hosted brain. Response shape is {signup_url, free_tier_quota, pro_value_prop} — no interruptions, the AI routes the user cleanly.
• Six prebuilt templates — apply with npx -y @jtalk22/slack-mcp --apply-template <name> --channels C012,C034. Names: oncall-handoff, support-triage, exec-monday, sprint-tracker, customer-feedback, incident-room. Read them, fork them, edit them — they're JSON profiles.
• Setup wizard hosted bridge — six in-wizard moments surface the hosted free tier (no card) where it matches the user's pain. Stays out of the way otherwise.
• Prior reliability fixes carried forward — LevelDB token extraction, multi-profile enumeration, and explicit SIGTERM/SIGINT/SIGHUP/stdin shutdown handlers ship in 4.2.0 too.

Full release notes on GitHub releases/latest.

Hosted HTTP Mode

For remote MCP endpoints (Cloudflare Worker, VPS, etc.):

SLACK_TOKEN=xoxc-... \
SLACK_COOKIE=xoxd-... \
SLACK_MCP_HTTP_AUTH_TOKEN=change-this \
SLACK_MCP_HTTP_ALLOWED_ORIGINS=https://claude.ai \
node src/server-http.js

Details: docs/DEPLOYMENT-MODES.md

Troubleshooting

Tokens expired: Run npx -y @jtalk22/slack-mcp --setup or use slack_refresh_tokens (macOS). To prevent silent expiration during long Claude-idle windows, set up the optional token-refresh LaunchAgent.

DMs not showing: Use slack_list_conversations with discover_dms=true.

Client not seeing tools: Check JSON syntax in config, restart client fully.

More: docs/TROUBLESHOOTING.md

Docs

• Setup Guide
• API Reference
• Architecture
• Deployment Modes
• Use Case Recipes
• Troubleshooting
• Compatibility

Security

• Token files: chmod 600 (owner-only)
• macOS Keychain encrypted backup
• Web server binds to localhost only
• API keys: crypto.randomBytes
• See SECURITY.md

Contributing

PRs welcome. Run node --check on modified files before submitting.

License

MIT — See LICENSE

Disclaimer

Not affiliated with Slack Technologies, Inc. Uses browser session credentials — check your workspace's acceptable use policy.

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Hosted version live at mcp.revasserlabs.com: Free tier (no card), $9/mo Pro, $49/mo Team flat, Ops from $199/mo. Hosted owns the AI brain (smart_search, catch_me_up, triage), the scheduled morning catch-up DM at 8am workspace time (rolling out Q2 2026), permanent OAuth (no 2-week token rotation), 90-day Vectorize retention, and shared workflow profiles. The OSS package owns local stdio + the 16 Slack tools (12 read, 4 write) + workflow profile primitives (slack_workflow_save, slack_workflows). The 3 paid stubs (slack_smart_search, slack_catch_me_up, slack_triage) appear in OSS as discoverable upgrade prompts.