hooks

Claude Code Slack Notification System

A lightweight tool for sending Slack notifications when Claude Code requires human intervention or when tasks are completed.

✨ Features

• 🔔 Automatic Notifications: Automatically send Slack messages when Claude Code needs approval or tasks complete
• 🎨 Rich Messages: Create beautiful notifications using Slack Block Kit
• ⚙️ Flexible Configuration: Support for multiple event types and custom triggers
• 🔒 Secure: Manage sensitive information through environment variables
• 📬 Dual Mode Support: Send via Webhook or Direct Message (DM)
• 📦 Minimal Dependencies: Webhook mode uses only Python stdlib, DM mode requires slack-sdk

📦 Files

File	Description
claude_slack_notifier.py	Main notification script
hooks_minimal.json	Minimal configuration example (recommended)
hooks_example.json	Complete configuration example

🚀 Quick Start

Option 1: Direct Message Mode (Recommended)

Send notifications as direct messages to your Slack account.

Step 1: Create Slack App and Get Credentials

1. Visit https://api.slack.com/apps and create a new app
2. Go to OAuth & Permissions and add these scopes:
   • chat:write
   • users:read
3. Install the app to your workspace
4. Copy the Bot User OAuth Token (starts with xoxb-)
5. Get your Member ID:

   # Visit Slack in browser, click your profile -> Copy member ID
   # Or use: https://api.slack.com/methods/users.list/test

Step 2: Install Slack SDK

pip install slack-sdk

Step 3: Set Environment Variables

export SLACK_CLAUDE_CODE_BOT_TOKEN="xoxb-your-bot-token-here"
export SLACK_MEMBER_ID="U01234567"

Add to ~/.bashrc or ~/.zshrc to make it permanent.

Step 4: Configure Claude Code

Edit ~/.claude/settings.json:

{
  "hooks": {
    "Notification": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/bin/claude_slack_notifier.py --event-type notification --mode dm",
            "timeout": 10
          }
        ]
      }
    ],
    "Stop": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/bin/claude_slack_notifier.py --event-type stop --mode dm",
            "timeout": 10
          }
        ]
      }
    ]
  }
}

Step 5: Activate in Claude Code

Run in Claude Code:

/hooks

Then review and approve the configuration.

---

Option 2: Webhook Mode

Send notifications to a Slack channel via Incoming Webhooks.

Step 1: Get Slack Webhook URL

1. Visit https://api.slack.com/apps
2. Create a new app and enable Incoming Webhooks
3. Copy the generated Webhook URL

Step 2: Set Environment Variable

export SLACK_WEBHOOK_URL="https://hooks.slack.com/services/YOUR/WEBHOOK/URL"

Add to ~/.bashrc or ~/.zshrc to make it permanent.

Step 3: Configure Claude Code

Edit ~/.claude/settings.json:

{
  "hooks": {
    "Notification": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/bin/claude_slack_notifier.py --event-type notification --mode webhook",
            "timeout": 10
          }
        ]
      }
    ],
    "Stop": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/bin/claude_slack_notifier.py --event-type stop --mode webhook",
            "timeout": 10
          }
        ]
      }
    ]
  }
}

Step 4: Activate in Claude Code

Run in Claude Code:

/hooks

Then review and approve the configuration.

📖 Usage Examples

Basic Usage

After installation, Claude Code will automatically send notifications in the following situations:

1. When Approval is Needed (Notification event)

   • Example: When executing dangerous commands
   • Example: When modifying important files

2. When Tasks Complete (Stop event)

   • At the end of any conversation
   • Review results and decide next steps

Manual Testing

# Test DM mode
echo '{"notification":"Test message"}' | \
  python3 ~/bin/claude_slack_notifier.py \
  --event-type notification \
  --mode dm \
  --message "This is a test message"

# Test Webhook mode
echo '{"notification":"Test message"}' | \
  python3 ~/bin/claude_slack_notifier.py \
  --event-type notification \
  --mode webhook \
  --message "This is a test message"

Monitor Specific Tools

Notify only on file modifications:

{
  "PostToolUse": [
    {
      "matcher": "Edit|Write",
      "hooks": [
        {
          "type": "command",
          "command": "python3 ~/bin/claude_slack_notifier.py --event-type post_tool_use"
        }
      ]
    }
  ]
}

📊 Supported Event Types

Event	Trigger	Recommended
Notification	Claude Code requests user approval	✅
Stop	Task completion	✅
UserPromptSubmit	User submits new task	Optional
PreToolUse	Before tool execution	Optional
PostToolUse	After tool execution	Optional
PreCompaction	Before context compression	Optional
SessionStart	Session begins	Optional

🎨 Message Examples

Notification Event

🔔 Claude Code Needs Your Action

Time: 2025-10-11 10:30:15
Event Type: notification

Notification:
About to execute command 'rm -rf /tmp/*', confirmation needed

Stop Event

✅ Claude Code Task Completed

Time: 2025-10-11 10:35:42
Event Type: stop

Session ID: abc123-def456

🔧 Advanced Configuration

Use Different Channels for Different Projects

Create .claude/settings.json in project directory:

{
  "hooks": {
    "Stop": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/bin/claude_slack_notifier.py --event-type stop --webhook-url 'https://hooks.slack.com/services/PROJECT/SPECIFIC/URL'"
          }
        ]
      }
    ]
  }
}

Customize Message Format

Modify the create_notification_blocks function in the script to customize message layout.

Add Conditional Filtering

Use environment variables or script logic to filter certain notifications:

# Only send notifications during work hours
if [ $(date +%H) -ge 9 ] && [ $(date +%H) -le 18 ]; then
  python3 ~/bin/claude_slack_notifier.py --event-type stop
fi

🐛 Troubleshooting

Not Receiving Notifications?

For DM Mode:

1. Verify environment variables:

   echo $SLACK_CLAUDE_CODE_BOT_TOKEN | head -c 20
   echo $SLACK_MEMBER_ID

2. Verify slack-sdk is installed:

   python3 -c "import slack_sdk; print('OK')"

3. Test the script:

   echo '{}' | python3 ~/bin/claude_slack_notifier.py --event-type stop --mode dm --message "Test"

For Webhook Mode:

1. Verify Webhook URL:

   echo $SLACK_WEBHOOK_URL

2. Test the script:

   echo '{}' | python3 ~/bin/claude_slack_notifier.py --event-type stop --mode webhook --message "Test"

Common Issues:

3. Check if Claude Code loaded the configuration:

   /hooks
   

4. View logs:

   ls -la ~/.claude/logs/

Notifications Too Frequent?

Keep only critical events (Notification and Stop), or use matcher to filter specific tools.

Python Related Errors?

Ensure you're using Python 3.6+:

python3 --version

"slack_sdk not installed" Error?

Install the Slack SDK:

pip install slack-sdk
# or
pip3 install slack-sdk

📚 Resources

• Claude Code Official Documentation
• Slack API Documentation
• Slack Webhooks Documentation
• Slack Block Kit Builder
• slack-sdk Documentation

🤝 Contributing

Issues and Pull Requests are welcome!

📄 License

MIT License

🙏 Acknowledgments

Built on Claude Code's hooks system and Slack's Incoming Webhooks API.