Lesson 5 · 7 min

Skills

Modular capability packs with their own prompts and resources.

Skills live in .claude/skills/ and bundle a SKILL.md prompt with optional scripts and resource files. They auto-load when relevant and are the cleanest way to share repeatable expertise across a team.

Production scenario

Real-world example: A "Stripe debugger" skill

The billing team's Stripe integration is hairy. They built a stripe-debug skill in .claude/skills/stripe-debug/:

SKILL.md — "When the user mentions a charge ID or a payment failure, pull the charge, dispute history, and recent invoices; explain the failure code in plain English."
scripts/fetch-charge.sh — wrapper around the Stripe CLI
reference/error-codes.md — internal cheat sheet of every code they care about

The skill auto-loads when the user mentions a Stripe-related issue. Engineers get expert behavior without typing the same setup prompt every time.

Why this matters: skills encapsulate repeated expertise. They're how a team levels up its juniors and reduces onboarding time on tricky subsystems.

Knowledge points in this lesson

Skills live in .claude/skills/{name}/SKILL.md
Bundle prompt + optional scripts and resources
Skills auto-load when context matches
Descriptive — "knows how to do X"
Best way to share recurring expertise
Skill description triggers auto-activation

Quick check

Claude CodeSelect all that apply

Which of the following can a PreToolUse hook do? (Select all that apply)