Book-to-Skill Distillation

Transform technical books into structured skill reference files that provide the WHY behind decisions during development. This is a multi-session process — each session handles ~3 chapters. The skill produces concept-organized reference files with author attribution, suitable for progressive disclosure in Claude Code skills.

The reference files are written into a target skill — either an existing skill you extend or a new one you create — inside the consuming project (${CLAUDE_PROJECT_DIR}/.claude/skills/<target-slug>/). Name the target skill when you invoke the tool. Slugify the target name (lowercase alphanumerics and hyphens only — strip /, \, and ..) before building any path, and verify the resolved directory stays under ${CLAUDE_PROJECT_DIR}/.claude/skills/ before writing.

Example shape: a testing skill distilled from two books — Beck's Test-Driven Development by Example and Khorikov's Unit Testing — producing ~14 reference files, with shared files where the authors overlap.

Usage caution — copyright

This tool is a neutral distiller: it applies a method, it does not judge what you feed it. A condensation of a copyrighted book is a derivative work (17 U.S.C. §§ 101, 106) — the rights holder's exclusive rights include preparing and distributing derivatives. Keeping a private distillation for your own study is a different act from publishing, committing, or sharing one; fair use is a defense raised after the fact, not a safe harbor you can assume in advance. You own the rights decision for every book you distill and for where its outputs go. Distribute or publish a distilled output only once you have satisfied yourself that doing so is lawful for that book. This is a caution, not legal advice.

Quick decision guide

• "New skill or extend existing?" → If the book's discipline matches an existing skill (e.g., a testing book matches a testing skill), extend it. Otherwise create a new skill
• "One file per chapter or per concept?" → Per concept. Chapters often split across concepts or overlap
• "How many sessions will this take?" → Roughly: total chapters / 3, plus 1-2 sessions for merges, SKILL.md update, and polish
• "PDF or EPUB?" → PDF works natively with the Read tool (pages: "1-20"). EPUB requires unzipping and text extraction. PDF is simpler
• "How do I resume across sessions?" → The continuation prompt (generated at session end) tells the next session exactly where to pick up