How to Build Custom OpenClaw Skills: A Complete Developer Guide

Building custom OpenClaw skills is one of the most powerful ways to extend your AI agent's capabilities. Whether you need a specialized workflow, integration with a proprietary system, or a unique automation, this guide will walk you through everything you need to know.

What Are OpenClaw Skills?

OpenClaw skills are self-contained packages that teach your AI agent how to perform specific tasks. Each skill consists of:

• SKILL.md - The instruction manual that tells OpenClaw what the skill does and how to use it
• Scripts/Tools - Executable code (bash, Python, Node.js) that performs the actual work
• Configuration - Settings, API keys, and environment variables

Think of skills as plugins or extensions for your AI assistant.

The Anatomy of a OpenClaw Skill

Every skill follows a standard structure:

my-skill/
├── SKILL.md          # Required: Instructions and documentation
├── scripts/
│   ├── main.py       # Main executable
│   └── utils.py      # Helper functions
├── config/
│   └── settings.json # Configuration
└── examples/
    └── usage.md      # Example prompts

Step 1: Define Your Skill's Purpose

Before writing code, clearly define what your skill should do:

1. What problem does it solve? Be specific.
2. What inputs does it need? API keys, file paths, parameters.
3. What outputs does it produce? Files, messages, data.
4. What external services does it use? APIs, databases, tools.

Example: "My skill monitors a Supabase database for new orders and sends Slack notifications."

Step 2: Create the SKILL.md File

The SKILL.md is the brain of your skill. OpenClaw reads this to understand how to use your skill.

# Order Notification Skill

## Purpose
Monitor Supabase for new orders and send Slack notifications.

## Requirements
- Supabase URL and API key
- Slack webhook URL

## Usage
Run the monitor script with:
\`\`\`bash
python scripts/monitor.py
\`\`\`

## Example Prompts
- "Check for new orders in the last hour"
- "Start monitoring orders and notify me on Slack"

Step 3: Write Your Scripts

Keep scripts modular and well-documented:

#!/usr/bin/env python3
"""
Order Monitor - Checks Supabase for new orders
"""
import os
import requests
from datetime import datetime, timedelta

SUPABASE_URL = os.environ.get('SUPABASE_URL')
SUPABASE_KEY = os.environ.get('SUPABASE_KEY')
SLACK_WEBHOOK = os.environ.get('SLACK_WEBHOOK')

def check_new_orders(since_hours=1):
    """Fetch orders created in the last N hours."""
    since = datetime.utcnow() - timedelta(hours=since_hours)
    
    response = requests.get(
        f"{SUPABASE_URL}/rest/v1/orders",
        headers={
            "apikey": SUPABASE_KEY,
            "Authorization": f"Bearer {SUPABASE_KEY}"
        },
        params={
            "created_at": f"gte.{since.isoformat()}"
        }
    )
    return response.json()

def notify_slack(message):
    """Send notification to Slack."""
    requests.post(SLACK_WEBHOOK, json={"text": message})

if __name__ == "__main__":
    orders = check_new_orders()
    if orders:
        notify_slack(f"🛒 {len(orders)} new order(s) received!")
        print(f"Found {len(orders)} orders")
    else:
        print("No new orders")

Step 4: Handle Configuration

Use environment variables for sensitive data:

{
  "name": "order-monitor",
  "version": "1.0.0",
  "required_env": [
    "SUPABASE_URL",
    "SUPABASE_KEY", 
    "SLACK_WEBHOOK"
  ]
}

Step 5: Test Your Skill

Before deploying, test thoroughly:

1. Unit tests - Test individual functions
2. Integration tests - Test with real services
3. Prompt tests - Verify OpenClaw understands the skill

Best Practices for OpenClaw Skills

Do:

• ✅ Write clear, concise SKILL.md files
• ✅ Use environment variables for secrets
• ✅ Include example prompts
• ✅ Handle errors gracefully
• ✅ Log important actions
• ✅ Make scripts idempotent (safe to run multiple times)

Don't:

• ❌ Hardcode API keys
• ❌ Write overly complex single scripts
• ❌ Ignore error handling
• ❌ Skip documentation

Advanced: Multi-Tool Skills

For complex workflows, combine multiple tools:

# Content Pipeline Skill

## Tools
1. `research.py` - Research a topic online
2. `outline.py` - Generate article outline
3. `write.py` - Write full article
4. `publish.py` - Publish to CMS

## Workflow
1. Run research for topic
2. Generate outline from research
3. Write article from outline
4. Publish to WordPress

Publishing Your Skill

Share your skills with the community:

1. GitHub - Push to a public repository
2. OpenClaw - Submit to the official registry
3. OpenClaw Skill Packs - Contribute to openclawskillpacks.com

Conclusion

Building custom OpenClaw skills empowers you to automate anything. Start small with a simple script, document it well, and iterate. The best skills solve real problems and are easy for both humans and AI to understand.

Ready to get started? Browse our skill directory for inspiration, or use our skill builder to generate a skill template automatically.