Slack MCP Server – Search, Messaging, and Canvases
Slack's official hosted MCP server gives approved AI clients secure, permission-aware access to supported Slack search, messaging, canvas, channel, file, and user tools. Use it to retrieve team context, send messages, create or update canvases, and support collaborative workflows from AI agents.
Overview
Slack's official MCP server connects compatible AI agents to Slack workspaces
through a managed remote endpoint. It is designed specifically for LLM-driven
discovery and actions, returning human-readable context from Slack while
enforcing the permissions granted to the authenticated user and registered app.
What the MCP server enables
Depending on the Slack app's user-token scopes, workspace approval, and the
authenticated user's access, an AI agent can:
- Search messages and files with filters for dates, users, and content types.
- Search public and private channels, users, and custom emoji.
- Retrieve channel histories, complete threads, files, and related metadata.
- Send or draft messages to Slack conversations.
- Create public channels, private channels, direct messages, and group DMs.
- Add emoji reactions to messages.
- Create, update, read, and export Slack canvases as Markdown.
- Retrieve user profiles, custom fields, statuses, and channel membership.
When to use it
Use Slack MCP when an AI workflow needs current team communication context or
must perform an authorized Slack action. Practical workflows include finding
past decisions, summarizing project discussions, retrieving a complete thread,
drafting or sending an announcement, creating a channel for a new initiative,
turning meeting notes into a canvas, and bringing Slack context into another
approved agent workflow.
Connection and authentication
Slack provides a hosted Streamable HTTP endpoint at
https://mcp.slack.com/mcp. Slack does not support SSE-based connections or
Dynamic Client Registration. MCP clients must be backed by a registered Slack
app with a fixed app ID.
Slack uses confidential OAuth for MCP clients. The client uses the Slack app's
client_id and client_secret, and the user completes OAuth consent. The
resulting user access token is sent as a Bearer token. Required user scopes
vary by tool, including search, history, chat, canvas, reaction, file, channel,
and user scopes.
Key considerations
Only apps published in the Slack Marketplace and internal apps may use Slack
MCP; unlisted apps are prohibited. Workspace administrators can approve and
manage MCP integrations, and activity can be audited through Slack audit logs.
All tools are subject to Slack Web API rate limits, with limits enforced by
action type. Use least-privilege scopes, require confirmation before sending or
changing content, and be cautious when combining Slack with other MCP servers
because doing so can expose sensitive workspace data across systems.
Supported Transports
streamable_http
URL: https://mcp.slack.com/mcp
Frequently Asked Questions
- When should an AI agent use the Slack MCP server?
- Use it when a workflow needs live Slack context or authorized Slack actions, such as searching team history, retrieving channels or threads, sending messages, creating conversations, managing canvases, or looking up users.
- What does the Slack MCP server add to an AI agent's capabilities?
- It gives the agent structured access to current Slack messages, files, channels, threads, canvases, users, profiles, and supported actions instead of relying only on static model knowledge or manually pasted conversations.
- What can an AI agent access or manage through Slack MCP?
- Depending on user-token scopes and workspace permissions, the agent can search messages, files, channels, users, and emoji; retrieve histories and threads; send messages; create conversations; add reactions; manage canvases; and retrieve user and membership information.
- How is authentication configured for the Slack MCP server?
- Slack uses confidential OAuth. The MCP client must be associated with a registered Slack app and use that app's client_id and client_secret. After user consent, the resulting user access token is sent as a Bearer token with only the scopes required by the enabled tools.
- Which transport should be used for the Slack MCP server?
- Use Streamable HTTP with https://mcp.slack.com/mcp. Slack explicitly does not support SSE-based MCP connections, and no official local stdio server is documented for the hosted Slack MCP service.