slackxmcp

slackxmcp is an open-source Slack stdio MCP server built on top of the official @slack/bolt, @slack/web-api, commander, and @modelcontextprotocol/sdk.

It lets MCP-compatible clients interact with Slack through Web API tools and optionally subscribe to inbound Slack messages through a Socket Mode powered MCP notification channel.

Highlights

• Exposes Slack as an MCP server over stdio.

• Uses Slack Bolt Socket Mode for inbound event delivery.

• Uses the official Slack Web API client for reads and writes.

• Supports interactive configuration via slackxmcp configure.

• Provides tools for identity, status, conversation lookups, history, thread replies, and common message mutations.

• Can emit incoming Slack message events over an optional MCP notification channel.

Requirements

• Node.js 24+

• A Slack app with Socket Mode enabled

Slack App Setup

At minimum, configure:

• Socket Mode enabled with an app token that has connections:write

• Token scopes for whichever Slack token you use:

  • channels:read

  • groups:read

  • im:read

  • mpim:read

  • channels:history

  • groups:history

  • im:history

  • mpim:history

  • chat:write

  • reactions:write

  • users:read

• Event subscriptions for the message surfaces you care about, such as:

  • message.channels

  • message.groups

  • message.im

  • message.mpim

Depending on your workspace policy and the conversations you target, Slack may require additional scopes.

If you want to use slack_search_messages, you will typically also need a user token with search:read because Slack does not expose message search through bot tokens.

Installation

Use it without installing globally:

npx slackxmcp mcp

Or for local development:

npm install
npm run build
npm run dev -- mcp

Quick Start

1. Run the interactive configuration:

slackxmcp configure

This writes:

~/.slackxmcp/config.json

2. Start the MCP server:

npx slackxmcp mcp

3. If your MCP host supports notifications and you want inbound Slack events, enable channels:

npx slackxmcp mcp --channels

The server uses stdio, so it is meant to be launched by an MCP client or wrapper rather than browsed directly in a terminal.

CLI Usage

MCP Server

npx slackxmcp mcp

Starts the stdio MCP server for the configured Slack app.

Configure

npx slackxmcp configure

Then opens an interactive configure UI (Ink) to manage:

• App token

• Bot token

• User token

• Allowed users

• Allowed channels

Allowlist items are toggled from menu screens (select an entry to toggle it, then choose Back).

Allowed users/channels screens support live type-to-filter search with a 5-row scroll viewport for faster selection in large workspaces.

Everything is persisted to:

~/.slackxmcp/config.json

MCP Tools

The server currently exposes these tools:

• slack_get_me

• slack_get_status

• slack_get_channel

• slack_get_channel_members

• slack_list_channels

• slack_list_users

• slack_search_messages

• slack_get_channel_history

• slack_get_thread_replies

• slack_send_message

• slack_send_files

• slack_reply_to_message

• slack_react_to_message

• slack_edit_message

• slack_delete_message

Push Channel

When started with --channels, the server:

• advertises the experimental MCP capability hooman/channel

• advertises hooman/user with path meta.user

• advertises hooman/session with path meta.session

• advertises hooman/thread with path meta.thread

• advertises hooman/channel/permission for remote daemon approvals

• emits notifications/hooman/channel for inbound Slack message events

If allowlist entries are configured, notifications/hooman/channel events are emitted only when either:

• meta.session (conversation ID) is in allowlist.channels, or

• meta.user (sender user ID) is in allowlist.users

When no allowlist is configured (or both arrays are empty), all inbound channel events are emitted.

Each notification includes:

• content: a JSON-encoded event payload

• meta.source: always slack

• meta.user: the Slack sender ID when available

• meta.session: the Slack conversation ID

• meta.thread: the Slack thread timestamp, or the message timestamp for non-threaded messages

The JSON-decoded content payload includes:

• source

• self

• message

• text

Inbound notification messages ignore Slack bot/system message subtypes.

When Hooman sends notifications/hooman/channel/permission_request, slackxmcp posts the request back into the originating Slack conversation/thread with Block Kit action buttons derived from params.options (defaults: allow once, always allow, deny). Tapping a button is relayed back over notifications/hooman/channel/permission. There is no text-command approval path; the Slack app must have Interactivity enabled so Bolt can receive block_actions over Socket Mode.

License

See LICENSE file.