Slack Bridge for Claude Code

Turn Claude Code into an autonomous AI agent you control from Slack — on any device, for $20/month.

Send a message from your phone. Get a deployed app back. No API costs.

What it does

This is a ~150-line Node.js bridge that connects Slack to Claude Code running on your machine. Claude Code uses your Pro/Max subscription (not the API), so there are no per-token costs.

• Send a Slack message → Claude Code runs on your Mac/Linux box
• Full agent capabilities — shell, file system, deployments, databases, web search
• Conversation continuity — each Slack channel maintains its own session
• File transfers — attach files in Slack, get output files back
• Socket Mode — no public URL or tunneling required
• Heartbeat updates — shows "Working... (30s)" so you know it's alive

Architecture

Phone/Laptop → Slack → Socket Mode → Bridge (Node.js) → Claude Code CLI → Your Machine
                                                              ↓
                                                         CLAUDE.md
                                                    (agent instructions)

Quick Start

1. Create a Slack App

1. Go to api.slack.com/apps → Create New App → From scratch
2. Enable Socket Mode (Settings → Socket Mode → toggle on) — save the xapp- token
3. Add Bot Token Scopes (OAuth & Permissions):
   • chat:write
   • files:read
   • files:write
   • im:history
   • im:read
   • im:write
   • app_mentions:read
4. Subscribe to Events (Event Subscriptions → toggle on):
   • message.im
   • app_mention
5. Install the app to your workspace — save the xoxb- token

2. Install Claude Code

npm install -g @anthropic-ai/claude-code
claude  # authenticate with your Pro/Max account

3. Clone and configure

git clone https://github.com/Markuspg1/slack-bridge-claude-code.git
cd slack-bridge-claude-code
cp .env.example .env

Edit .env with your tokens:

SLACK_BOT_TOKEN=xoxb-your-bot-token
SLACK_APP_TOKEN=xapp-your-app-token
ALLOWED_USERS=U01ABCDEF   # your Slack user ID (optional)
CLAUDE_WORKING_DIR=/Users/you/workspace

4. Customize CLAUDE.md

Edit CLAUDE.md to describe your machine, tools, and conventions. Claude Code reads this at the start of every session. The included file is a template — make it yours.

5. Run it

# One-off
npm start

# Persistent (survives reboots)
npm install -g pm2
pm2 start start.sh --name claude-bridge
pm2 save
pm2 startup

6. Use it

DM your bot in Slack or @mention it in a channel:

"Deploy the CRM app to production"

"Create a new React project with Tailwind and Supabase auth"

"Check my calendar for tomorrow and summarize it"

How it works

Component	Purpose
src/index.js	Slack listener + Claude Code spawner
start.sh	Startup script with dependency checks
CLAUDE.md	Agent instructions (customize this)
.env	Secrets (Slack tokens, config)
sessions.json	Auto-managed session store for conversation continuity

The bridge spawns claude -p <prompt> --output-format json as a child process. Key flags:

• --output-format json — structured output with session IDs
• --max-turns 25 — caps agentic loops
• --resume <session_id> — continues previous conversations
• --allowedTools — restricts which tools Claude can use

Configuration

Variable	Default	Description
SLACK_BOT_TOKEN	required	Bot token (xoxb-...)
SLACK_APP_TOKEN	required	App-level token (xapp-...) for Socket Mode
ALLOWED_USERS	"" (everyone)	Comma-separated Slack user IDs
CLAUDE_WORKING_DIR	$HOME	Where Claude Code runs
MAX_TURNS	25	Max agentic turns per request
HEARTBEAT_SEC	15	Seconds between "Working..." updates

What you get vs. what you give up

You get:

• Full Claude Code agent from any device via Slack
• $20/month flat — no API costs
• Shell, file system, git, deployments, databases
• Conversation memory within channels

You give up:

• Rate limits on Pro (less restrictive on Max)
• No streaming — you get the full response when done
• Single agent (no parallel multi-agent orchestration)

For most workflows — "build this", "deploy that", "check my calendar" — the bridge covers it.

Background

This project was born when Anthropic removed third-party tool access from subscription plans on April 4th, 2026. Read the full story: Anthropic Killed My AI Agent Platform — Here's How I Rebuilt It for $20/month

License

MIT