book-to-skill

virgiliojr94/book-to-skill

Turn any technical book PDF into a Claude Code skill, ready to study, reference and use while you work

https://github.com/virgiliojr94/book-to-skill

book-to-skill fixes a familiar problem: you read a great technical book once, and 3 months later you can't remember chapter 7 existed. Point it at the PDF and it builds an agent skill from it: the book's frameworks, decision rules and anti-patterns, with one file per chapter. Then you ask your coding agent a question, and it reads the right chapter and answers from the real content.

It's structure, not a summary. And it works on anything you re-read often: internal docs, brand guidelines, specs, or a pile of research papers.

What it generates

A run creates a skill folder with 5 kinds of file:

The chapter files cost nothing until a question needs them. The author measured 24 to 51 times fewer tokens than putting the whole book in the agent's context to answer 1 question.

For business people

The problem: books, playbooks and internal documentation hold knowledge that nobody re-reads. Searching a PDF gives you pages, not answers. Asking an AI about a book it hasn't read gives you guesses.

What it changes: the book becomes a reference your AI assistant actually uses. Type /my-book pricing and the agent answers from that book's chapter on pricing.

Where it fits beyond books:

• Internal documentation: runbooks, onboarding guides and decision records as 1 skill.
• Brand and design guidelines: a 60-page brand book the team can query.
• Research: papers plus your own notes, merged and updated as new material arrives.
• Specs and standards: API contracts, RFCs and compliance documents.

Costs: the tool is free. The generation step runs on your agent's model, once per book.

Copyright, from the README: the tool ships no book content. You convert files you own, and the result counts as your own study notes. Don't publish a skill made from someone else's book: keep those private.

For technical people

Install it as a skill:

npx skills add virgiliojr94/book-to-skill
# or
git clone https://github.com/virgiliojr94/book-to-skill.git ~/.claude/skills/book-to-skill

Use it from the agent:

/book-to-skill ./designing-data-intensive-applications.pdf
/book-to-skill ./docs/ internal-handbook
/ddia replication

• 2 halves: a deterministic Python extractor (document to clean text and metadata) and a generator, which is your agent following the SKILL.md spec.
• Where skills land: ~/.agents/skills/<slug>/, the shared folder most agents read, with a checked symlink into ~/.claude/skills/<slug>/ for Claude Code.
• PDF extraction: it asks whether the book is technical or prose. docling keeps tables and code blocks (about 1.5 seconds a page), pdftotext is instant for prose. Scanned PDFs need OCR first, for example with ocrmypdf.
• Check your setup: python3 scripts/extract.py --check lists the installed extractors and what's missing.
• Modes: analyse only, generate from an earlier analysis, and update to fold new material into an existing skill. It can also publish the skill to a private GitHub repo for npx skills add on other machines.
• Validation: tools/validate_skill.py checks a generated skill against each host's rules.

Value

I keep reading notes on sales and leadership books in this notebook, but notes are for me. A skill is for my agents. The obvious first candidates are the books my sales work is built on, and the Kaltura brand and product guidelines, so a drafting agent answers from the source instead of from memory.

The update mode matters most: a skill that grows as I add material, instead of a one-off conversion. And the copyright rule is simple: skills from bought books stay private, on my machine.

Further Reading

How it works

The extraction modes, token budgets and the full step-by-step process

https://github.com/virgiliojr94/book-to-skill/blob/master/docs/how-it-works.md

Performance and the discovery loop tax

How the 24 to 51 times token saving was measured

https://github.com/virgiliojr94/book-to-skill/blob/master/docs/performance.md