Introduction

Claude Skills is a library of structured workflows — called skills — that you invoke with a single slash command in Claude Code. Each skill encodes domain knowledge, step-by-step processes, quality gates, and self-review checklists so Claude handles complex tasks reliably, every time.

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The problem skills solve

Claude Code is powerful out of the box, but complex tasks — scaffolding a Python library, initializing a GitHub repo with CI/CD, diagnosing flaky tests, shipping a product idea end-to-end — require careful prompting and domain knowledge that gets lost between sessions. You end up re-explaining the same workflows, catching the same mistakes, and missing the same steps. Skills fix that. Each skill is a directory of markdown files that Claude loads as context when you invoke it. The domain knowledge, workflow steps, and quality rules are encoded once and reused every time.

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How a skill is structured

Every skill is a directory containing a SKILL.md entrypoint and optional reference files. SKILL.md is the table of contents for the skill. It contains:

• Numbered workflow steps, each pointing to a reference file for details
• Golden rules — hard, mechanical constraints that prevent common mistakes
• A self-review checklist Claude runs before delivering output

Reference files contain the detailed guidance: templates, code patterns, examples, and domain knowledge. They are loaded progressively — only when Claude needs them — so context stays focused. This architecture has four key properties:

• Table-of-contents structure — SKILL.md stays concise (~50–100 lines). Details live one level deeper in reference files.
• Progressive disclosure — Only SKILL.md loads on invocation. Reference files load on demand, keeping the context window efficient.
• Golden rules — Each skill encodes 3–8 hard mechanical rules that prevent the most common failure modes for that domain.
• Feedback loops — Every skill includes at least one do → check → fix cycle, so errors are caught and corrected before output is delivered.

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Skill categories

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Next steps