Creating Custom Skills

Custom skills let you encode your most common workflows into reusable commands. This is where Claude Code becomes truly personalized.

Skill File Structure

Skills are markdown files with frontmatter that define their behavior:

---
name: my-skill
description: What this skill does
---

The prompt that Claude will execute when this skill is invoked.
You can include multi-step instructions, templates, and rules.

Where Skills Live

Skills can be defined at multiple levels:

Location	Scope
~/.claude/skills/	Global — available in all projects
.claude/skills/	Project — available in this project only

Example: WordPress Deploy Skill

Let’s create a skill for deploying WordPress changes:

---
name: wp-deploy
description: Deploy WordPress theme changes to staging
---

Follow these steps to deploy the current theme changes:

1. Run the build process:
   - Execute `npm run build` in the theme directory
   - Verify the build succeeded with no errors

2. Check for common issues:
   - Grep for console.log statements and remove them
   - Verify no .env files are included
   - Check that all PHP files pass syntax validation

3. Create a deployment summary:
   - List all changed files since the last commit
   - Note any new dependencies added
   - Flag any database migration requirements

4. Stage and commit with a deploy-prefixed message

5. Push to the staging branch

Save this as .claude/skills/wp-deploy.md and use it with:

> /wp-deploy

Example: Code Review Skill

---
name: review
description: Thorough code review with security focus
---

Review the staged changes (or recent commits if nothing staged) with focus on:

## Security
- SQL injection, XSS, CSRF vulnerabilities
- Hardcoded secrets or credentials
- Insecure API endpoints
- Missing input validation

## Code Quality
- Functions over 50 lines
- Deeply nested conditionals
- Missing error handling at API boundaries
- Unused imports or variables

## Performance
- N+1 queries
- Missing database indexes for new queries
- Unnecessary re-renders in React components
- Large bundle additions

Format findings as:
- 🔴 Critical — must fix before merge
- 🟡 Warning — should fix, not blocking
- 🟢 Suggestion — nice to have

Skill Arguments

Skills can accept arguments:

> /review-pr 42

The argument (42) is passed to the skill and available in the prompt context.

Sharing Skills

Since skills are just markdown files:

• Commit them to your project repo for team sharing
• Create a personal skills repo for your global skills
• Share with the community — skills are portable across projects

Exercise

1. Think of a workflow you do repeatedly
2. Write it out as step-by-step instructions
3. Save it as a skill file in .claude/skills/
4. Test it by invoking the skill
5. Iterate — refine the instructions based on results