What are Claude Code Skills

Reusable capabilities Claude can apply automatically

Claude Code skills are reusable capabilities that Claude can apply automatically when your request matches the skill's purpose.

A skill encodes how Claude should behave in a recurring situation. Once installed, the skill is always available.

In aibuilder.sh, a skill is a folder installed at:

.claude/skills/<skill-name>/

Every skill must include a SKILL.md file.

How Claude Code Skills work

When you ask Claude to do something, Claude evaluates whether any installed skills are relevant.

If a skill matches the request:

  • Claude incorporates the instructions from the skill
  • You do not need to explicitly invoke it
  • The behavior applies consistently across sessions

Skills are best for:

  • Coding standards
  • Testing conventions
  • Review rules
  • Architectural guidelines
  • Repeatable reasoning patterns

When to use a Skill

Use a skill when:

  • You want Claude to follow rules automatically
  • The behavior should apply every time
  • You want consistency across tasks and repos

Do not use a skill for one-off actions. Use a command instead.

Installing a Skill

Install a skill with:

npx ai-builder add skill <skill-name>

This creates a folder under .claude/skills/.