Slack MCP Server

Slack MCP Server

Catch up on Slack without reading it.

Unreads, threads, and search — in your agent’s context, from the session you already have.

Set it up, then register it with your client.

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

claude mcp add slack -- npx -y @jtalk22/slack-mcp

Check where your credentials are stored and how old they are, or run it read-only so your agent can read Slack but never post.

npx -y @jtalk22/slack-mcp --doctor --security

npx -y @jtalk22/slack-mcp --read-only

On Enterprise Grid, Slack can end a session it sees being automated. Use Slack's official MCP server there.

Claude Code Claude Desktop Cursor Copilot Windsurf Gemini CLI Codex CLI any stdio MCP client

What’s new in 5.1 · ▶ the whole morning in three minutes · interactive walkthrough · setup guide

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If your workspace is on Slack's free plan

Checked against Slack's published plans and pricing on 2026-10-07.

A free workspace keeps 90 days of message history, allows 10 app integrations, and gets only Slack's basic AI. The AI people actually want — AI search across the workspace, channel recaps, Slackbot acting as an agent, AI workflow generation — starts on Business+ at $15 per user per month on annual billing ($18 month to month). Pro, at $7.25, buys unlimited history and unlimited apps, not the advanced AI. So a ten-person free workspace that wants an AI it can ask about its own Slack is looking at $1,800 a year, and the cheaper upgrade does not get them there.

This package gives that workspace an agent over the same Slack for nothing, running on the AI subscription its people already pay for. Three things follow from how it works:

• It installs no Slack app, so it uses none of your 10 app slots. If your workspace is already at the cap, this is the only way left to add an integration at all.
• It needs no admin approval, because it is not an app anyone has to approve. It reads Slack through your own browser session, with exactly the access you already have and nothing more.
• It can export what you can still see. On a free plan, history older than 90 days stops being reachable — Slack's own free export covers public channels only and is admin-only, so DMs and private channels are not in it. slack_get_full_conversation writes them out with their threads while they are still inside the window. It cannot retrieve anything already past the line; nothing can.

The browser-session route is not a workaround to apologise for. For a workspace Slack's own AI does not serve, it is the only route there is.

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Two ways into Slack

Slack's official MCP server is an app your workspace admin approves and controls. Use it when your organisation wants a sanctioned integration. This server uses the browser session already in Chrome instead, so there is no app to install and no admin to ask, and it runs as a local command for any stdio MCP client. It acts as you, with exactly your access.

Side by side: the managed integration path vs. the local session path

Is the local path against Slack's terms?

Treat browser-session automation as an acceptable-use decision for you and your workspace. The server acts as your signed-in Slack identity and cannot read a channel you cannot read or act as another user. It does not evade server-side retention, DLP, compliance exports, or audit controls.

"No admin request" means there is no Slack app installation to approve. It does not mean workspace activity disappears from Slack's systems. If your policy requires a sanctioned integration, use Slack's official MCP server.

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Install

Node 22 or 24 recommended. Node 20+ is supported and CI-tested.

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

Prefer a persistent CLI: npm install -g @jtalk22/slack-mcp then slack-mcp --setup.

Then:

1. Copy the stdio command --setup prints when it finishes.
2. Paste it into your client, or run the claude mcp add line it prints.
3. Fully restart the client.
4. Ask the agent to run slack_health_check.
5. A workspace name in the response means the connection is live.

Per-client configuration keys are in the setup guide.

Use the same server command everywhere:

{

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

On macOS, setup can extract from Chrome and persist the selected storage backend. On other platforms, provide SLACK_TOKEN and SLACK_COOKIE through the client's environment configuration. Docker, HTTP, and detailed client examples live in docs/SETUP.md and docs/DEPLOYMENT-MODES.md.

Client configuration matrix

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20 tools: read, act, automate

Read channels, DMs, threads and search; act with a reply, a reaction or a read-state change; run the catch-up and typed workflows locally. The surface is 20 tools today: 13 read-only operations, 4 write-path tools that each carry an MCP destructive annotation so clients can gate workspace writes, and 3 local workflow tools. One of the reads is slack_session_report, which reads nothing from Slack: it returns what this process has done, as counts. Every tool does its work here — reads Slack or local state — and none is a placeholder for something you would have to pay for. Four read tools accept include_rich_message_fields: true to surface attachments, blocks, files, reactions, and metadata—complete inputs and response contracts live in docs/API.md.

Speaks MCP 2026-07-28 and every 2025 revision from the same binary — era-negotiated over stdio, stateless per request over HTTP (no Mcp-Session-Id; GET/DELETE answer 405). The claim is a test, not a sentence: test/mcp-era.test.js drives the real SDK client at both eras against the real entry points.

Advertising fewer tools. Every tool the server advertises sends its schema to the model on every turn, before you ask anything. SLACK_MCP_TOOLS=essentials advertises six (unread, history, search, thread, user lookup, send); SLACK_MCP_TOOLS=read the 13 read-only operations; --tools=slack_x,slack_y an explicit set. The default is all 20. Filtering changes what is advertised, not what is callable.

The full tool inventory

13 read-only operations