How to Build Claude Code Skills (Custom Slash Commands) That Actually Work

Claude Code skills are reusable slash commands that give Claude specific instructions for a task. Instead of prompting from scratch every time, you type /auth and Claude already knows your stack, your patterns, and exactly what to produce. Here's how to build your own. What a Skill Is A skill is a markdown file in your .claude/skills/ directory. When you type /skill-name in Claude Code, it loads that file and uses its contents as the instruction set. .claude/ skills/ auth.md pay.md test.md deploy.md Skill File Structure --- name: auth description: "Generate a complete authentication system for this project" --- You are implementing authentication for this project. Follow these steps: 1. Read the existing project structure first 2. Check what auth-related packages are already installed 3. Ask the user 3 questions before writing any code: - Which providers do you need? (Google, GitHub, email/password) - Do you need role-based access control? - Which pages should be protected? 4. Based on