Claude Code Slack Channel

Connect Claude Code to your Slack workspace using the Model Context Protocol (MCP). This server runs a Slack App in Socket Mode that routes incoming messages from Slack directly into your local Claude Code session, and gives Claude the ability to securely reply back!

Features

• Two-Way Communication: Send messages from Slack to Claude Code, and allow Claude Code to natively reply using an MCP tool (send_slack_message).

• Zero Configuration Tunnels: Uses Slack Socket Mode, meaning no ngrok or public IP addresses are required. Runs completely locally!

• Private Channel Support: Fully supports routing messages from private Slack channels.

Related MCP server: Claude Code MCP Server

Setup Instructions

1. Create a Slack App

1. Go to Slack API Apps and click Create New App > From scratch.

2. Go to Socket Mode (left sidebar) and toggle it On.

3. Generate an App-Level Token with the connections:write scope. (Starts with xapp-).

4. Go to OAuth & Permissions (left sidebar), scroll to Scopes > Bot Token Scopes, and add the channels:history, chat:write, and groups:history scopes.

5. Go to Event Subscriptions (left sidebar), toggle Enable Events to On, and subscribe to message.channels and message.groups under "Subscribe to bot events".

6. Important: Scroll to the bottom and click Save Changes.

7. Go to Install App and install it into your workspace to get your Bot User OAuth Token (Starts with xoxb-).

2. Configure Claude Code

You can add this MCP server to your global Claude Code configuration (~/.claude.json) or to a project-specific .claude.json configuration.

Run npm install in this directory to install the @slack/bolt and tsx dependencies. Then, add the following to your mcpServers block, replacing the path and tokens with your actual values:

{
  "mcpServers": {
    "slack-channel": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "tsx",
        "/path/to/this/repository/webhook.ts"
      ],
      "env": {
        "SLACK_APP_TOKEN": "xapp-...",
        "SLACK_BOT_TOKEN": "xoxb-...",
        "SLACK_CHANNEL_ID": "C0..." // Optional: add a channel ID here so it only listens to one specific channel!
      }
    }
  }
}

3. Usage

• Simply restart Claude Code. The server will initialize in the background and connect to Slack.

• Invite your bot to any channel in Slack using /invite @YourBotName.

• Send a message in that channel, and it will seamlessly appear in Claude Code as context!

• You can ask Claude Code directly to "Reply to that Slack message" and it will autonomously use the send_slack_message tool to post back.

⚠️ Architecture Caveat: Global vs. Local Configuration

Slack's Socket Mode allows multiple WebSocket connections using the identical App Token, and load-balances (randomizes) incoming messages across all connected clients.

Because of this:

• Global Configuration (~/.claude.json): If you have multiple Terminal windows open running Claude Code simultaneously, each window spawns its own MCP server. When you send a Slack message, Slack will randomly route it to only one of your active terminals.

• Local Configuration (./.claude.json): If you only want Slack messages to route uniquely to a specific project workspace, do not configure this server globally. Instead, configure the mcpServers block in a local .claude.json file inside that specific project folder so the webhook server is only spawned when you are actively working in that directory.

Troubleshooting

If messages aren't arriving:

• Ensure you have invited the bot to the channel.

• Ensure you clicked the yellow "Reinstall to Workspace" banner in Slack after changing event scopes.

• Check the slack-debug.log file generated in the root of this repository.