Essential Claude Code Skills and Commands

A practical guide to Claude Code's built-in skills and slash commands, covering the distinction between the two systems and how to use each effectively. Built-in skills covered include /simplify (parallel code quality review), /review (PR-style code review), /batch (large-scale parallel changes across a codebase), /loop (scheduled recurring prompts), /debug (session troubleshooting), and /claude-api (API reference loader). Slash commands covered include /compact, /diff, /btw, /copy, /rewind, /usage, /cost, /stats, /model, /fast, /memory, /context, and /plan. Also explains how to create custom skills using SKILL.md files with frontmatter options like disable-model-invocation, allowed-tools, and context: fork, plus workflow tips for chaining commands effectively.