slack-mcp

Slack MCP

Your entire Slack workspace — available to any AI.

A Model Context Protocol server that gives LLMs full access to Slack. Messages, channels, files, canvases, lists, search, reactions — all of it.

253 tools · 37 API families · Every Slack feature

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Quick Start

1. Create a Slack App

1. Go to api.slack.com/apps > Create New App > From a manifest
2. Paste the contents of manifest.json
3. Install to your workspace
4. Copy the User OAuth Token (xoxp-...) from OAuth & Permissions

2. Add to your AI client

claude mcp add slack -- uvx --from git+https://github.com/karbassi/slack-mcp.git slack-mcp

Then set SLACK_XOXP_TOKEN in your shell environment.

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "slack": {
      "type": "stdio",
      "command": "uvx",
      "args": ["--from", "git+https://github.com/karbassi/slack-mcp.git", "slack-mcp"],
      "env": {
        "SLACK_XOXP_TOKEN": "xoxp-..."
      }
    }
  }
}

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "slack": {
      "type": "stdio",
      "command": "uvx",
      "args": ["--from", "git+https://github.com/karbassi/slack-mcp.git", "slack-mcp"],
      "env": {
        "SLACK_XOXP_TOKEN": "xoxp-..."
      }
    }
  }
}

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

{
  "mcpServers": {
    "slack": {
      "type": "stdio",
      "command": "uvx",
      "args": ["--from", "git+https://github.com/karbassi/slack-mcp.git", "slack-mcp"],
      "env": {
        "SLACK_XOXP_TOKEN": "xoxp-..."
      }
    }
  }
}

Add to your VS Code settings.json:

{
  "mcp": {
    "servers": {
      "slack": {
        "command": "uvx",
        "args": ["--from", "git+https://github.com/karbassi/slack-mcp.git", "slack-mcp"],
        "env": {
          "SLACK_XOXP_TOKEN": "xoxp-..."
        }
      }
    }
  }
}

{
  "mcpServers": {
    "slack": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "--directory", "/path/to/slack-mcp", "slack-mcp"]
    }
  }
}

Run one long-lived server that every client shares, instead of one stdio process per session:

SLACK_MCP_TRANSPORT=http SLACK_MCP_PORT=8501 slack-mcp

{
  "mcpServers": {
    "slack": { "type": "http", "url": "http://127.0.0.1:8501/mcp" }
  }
}

The server has no auth of its own, so it only binds to loopback (SLACK_MCP_HOST must be 127.0.0.1, localhost, or ::1) and always turns on FastMCP's Host/Origin (DNS-rebinding) protection, which FastMCP leaves off by default. To reach it from elsewhere, put a reverse proxy you control in front and add the proxy's hostname to FASTMCP_HTTP_ALLOWED_HOSTS (and its origin to FASTMCP_HTTP_ALLOWED_ORIGINS), e.g. FASTMCP_HTTP_ALLOWED_HOSTS='["mcp.example.com"]'.

What Can It Do?

"Catch me up on #engineering from today" "Reply to Sarah's thread saying we'll ship it Monday" "Search for anything about the Q3 roadmap" "Create a channel called #project-atlas and invite the design team"

Domain	Tools	Highlights
Conversations	31	History, threads, replies, create, archive, invite, mark read, team connections, suggestions
Undocumented	38	Drafts, saved items, emoji management, granular search, sidebar, threads, activity inbox, DMs, AI unread summary + digests, Today view, Connect invites
Files	19	Upload, share, edit, list, remote files, shares, recently deleted, favorites
Chat	13	Send, reply, schedule, update, delete, ephemeral, stream
Users	15	Profile, presence, lookup, list, profile extras/sections, custom statuses
Lists	15	Create, edit items, manage access, my assigned items, templates, records
Legacy	11	Slash commands, file editing, bot listing
Team	9	Info, preferences, access logs, billing
Apps	9	Manifests, connections, authorizations, activities
Workflows	8	Featured workflows, step completion, workflow/trigger listing
Usergroups	7	Create, update, manage members
Canvases	7	Create, edit, sections, access control, templates
Calls	6	Start, end, manage participants
+ 24 more		Calendar, DND, reminders, bookmarks, reactions, pins, stars, views, search, auth, bots, emoji, ...

Plus resolve_names (bulk ID→name resolution) and cache_clear (bust the response cache on demand) utility tools.

Beyond the Official API

68 undocumented and legacy endpoints — the same internal APIs that Slack's own apps use. Requires session tokens (xoxc+xoxd).

Endpoint	What it provides
client.boot	Full workspace bootstrap — channels, users, prefs, feature flags
client.counts	Unread counts per channel/DM/thread plus mention counts
client.userBoot	User-specific bootstrap data scoped to the authenticated user
threads.getView	Thread inbox — the list of threads with read/unread state
subscriptions.thread.getView	My threads with unread reply counts — "catch me up on my threads"
subscriptions.thread.mark	Mark individual threads as read or unread
client.dms	Open DMs and group DMs (ims + mpims)
activity.feed	Activity inbox — mentions, reactions, replies, reminders, invites
drafts.list	List all unsent message drafts
drafts.create	Create a message draft with Block Kit text
drafts.update	Edit an existing draft
drafts.delete	Delete a draft
saved.list	List saved-for-later items
saved.get	Fetch specific saved-for-later items by id
saved.add	Save a message for later with optional due date
saved.delete	Remove a saved-for-later item
lists.getMyItems	Slack List tasks and approvals assigned to me
emoji.add	Add a custom emoji from a URL
emoji.remove	Remove a custom emoji
emoji.adminList	Emoji with rich metadata — uploader, date, usage stats
search.modules.messages	Granular message search
search.modules.files	File-specific search
search.modules.channels	Server-side channel search by name or topic
search.modules.people	Fuzzy people search by name, title, department
search.modules.dms	Search within DMs only
conversations.view	Channel view with read state and personal config
conversations.listPrefs	Per-channel notification and mute preferences
users.channelSections.list	Sidebar organization — custom sections, favorites
users.priority.list	Contacts ranked by interaction frequency
experiments.getByUser	A/B test experiment assignments
api.features	Workspace feature flags
aiApps.list	AI applications configured in the workspace
ai.alpha.summarize.unreadsSnapshot	AI summary of unread messages — "summarize what I missed"
ai.alpha.digest.list	Slack's AI recaps/digests of activity across channels
subscriptions.thread.get	Subscription/read state for a single thread
today.items.list	Today view items (suggested to-dos, highlights)
connectInvites.list	Pending Slack Connect channel and DM invites
conversations.teamConnections	Slack Connect connections for a channel
conversations.suggestions	Suggested channels for the user
conversations.bulkReacjiTriggers	Per-channel reacji (auto-reaction) triggers
lists.templates	Available Slack List templates
lists.records.list	Records/items within a given Slack List
calendar.getInstalledCalendars	Connected calendars (gcal, ocal)
calendar.user.status	The user's current calendar status
canvases.getCannedTemplates	Available canvas templates
emoji.collections.list	Installed and available emoji packs
files.getShares	Where a file is shared (channels, tabs, viewer count)
files.recentlyDeleted	Recently deleted files
files.favorites.list	Favorited files
functions.workflows.list	Workflows and their triggers
workflows.triggers.list	Triggers, filterable by app
users.profile.getExtras	Profile extras — shared channels, onboarding state
users.profile.getSections	Custom profile sections
users.customStatus.list	Saved and scheduled custom statuses
search.inline	Inline/quick search scoped to a channel or user
search.save	Save a search
enterpriseSearch.getConnectors	Configured enterprise search connectors

Endpoint	What it provides
chat.command	Execute slash commands programmatically
commands.list	List all slash commands including custom ones
files.edit	Edit a file's title, content, or filetype in-place
files.share	Share a file to a channel
bots.list	List all bot users in the workspace
team.prefs.get	Team-level preferences — retention, permissions, domains
users.prefs.get	All user preferences — notifications, sidebar, theme
users.prefs.set	Set any individual user preference
users.admin.invite	Invite users by email (Enterprise Grid)
users.admin.setInactive	Deactivate a user account (Enterprise Grid)
channels.delete	Dead method — included for completeness

[!WARNING] Undocumented endpoints can break without notice. They use session tokens (xoxc+xoxd) which expire and must be re-grabbed from browser cookies.

Authentication

Variable	Required	Description
SLACK_XOXP_TOKEN	Yes	User OAuth token from your Slack app
SLACK_XOXC_TOKEN	No	Browser session token for undocumented endpoints
SLACK_XOXD_TOKEN	No	Browser session cookie (paired with xoxc)

[!TIP] The xoxp token covers all Slack Web API tools. Utility tools like resolve_names and cache_clear work without additional auth. For undocumented endpoints (unread counts, workspace boot, file editing), you also need xoxc+xoxd — grab them from your browser cookies while logged into slack.com.

Caching

Responses are cached automatically to reduce API calls:

• Stable data (users, teams, bots, emoji) — 1 hour TTL
• Dynamic data (channel lists, members, bookmarks) — 5 minute TTL
• Old threads (conversations_replies with ts > 1 hour old) — 1 hour TTL
• Bounded history (conversations_history with old date range) — 1 hour TTL
• Resolved names (user/bot → 1 hour, channel → 5 minutes)

Cache is stored at the platform-native location (~/Library/Caches/slack-mcp on macOS, ~/.cache/slack-mcp on Linux). Set XDG_CACHE_HOME to override.

Use the cache_clear tool to bust the cache when you need fresh data.

Name Resolution

All tool responses automatically resolve user, channel, DM, and bot IDs to display names via a resolved_names field — no extra tool calls needed. Resolved names are disk-cached to avoid redundant API lookups.

Response Compaction

15 high-volume tools automatically strip bloat from Slack API responses — blocks (duplicates text), attachments (link unfurls), thumbnails (22 per file), and metadata noise. Measured reductions:

Endpoint	Before	After	Reduction
conversations.history	465 KB	113 KB	76%
files.list	127 KB	26 KB	80%
conversations.list	59 KB	17 KB	71%
reactions.list	353 KB	167 KB	53%

Compaction is on by default. Pass detailed=True to any compactable tool to get the full Slack API response.

Development

git clone https://github.com/karbassi/slack-mcp.git
cd slack-mcp
uv sync
uv run pre-commit install            # ruff + ty on every commit
mise run check                       # test + lint + security scan
mise run test:integration            # requires tokens in .env

[!NOTE] ~68 integration tests are skipped because they require a bot token (xoxb), Slack Connect, interactive triggers (e.g. views.open), or would be destructive (e.g. auth.revoke). Adding bot token support is a future goal.

License

MIT