multi-format-book-extractor

multi-format-book-extractor is a skill for Claude Code, Codex from Abilityai/cornelius. It costs 75 tokens per session (993 once invoked), scanned A, original, MIT.

A book-chapter extractor for PDF, MOBI, and AZW3 files that creates separate numbered Markdown files. Markdown is plain text with simple formatting; scanned PDFs can be read with Gemini-based optical character recognition, which converts page images into text.

In plain words
What is it for?
Use it to extract chapters from non-EPUB ebooks, process text-based PDFs, or convert scanned PDFs into searchable Markdown chapters.
Why use it?
It saves you from splitting books into chapters by hand and handles PDFs that contain only page images. MOBI and AZW3 files require Calibre, an ebook-conversion program.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/abilityai/cornelius/multi-format-book-extractor
Any agent
npx skills add Abilityai/cornelius --skill multi-format-book-extractor
Clone the repo
git clone --depth 1 https://github.com/Abilityai/cornelius

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for multi-format-book-extractor

README.md
[![agentmods](https://agentmods.dev/badge/skills/abilityai/cornelius/multi-format-book-extractor.svg)](https://agentmods.dev/skills/abilityai/cornelius/multi-format-book-extractor)
Your own site
<a href="https://agentmods.dev/skills/abilityai/cornelius/multi-format-book-extractor"><img src="https://agentmods.dev/badge/skills/abilityai/cornelius/multi-format-book-extractor.svg" alt="Measured on agentmods" height="20"></a>
Per session 75 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 993 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00075 $0.00993
Opus 5 $0.00037 $0.00496
Sonnet 5 $0.00015 $0.00199
Haiku 4.5 $0.00007 $0.00099

Measured 4d ago against content hash 0bfbe65c3115, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

multi-format-book-extractor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/multi-format-book-extractor/SKILL.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Multi-Format Book Extractor

Extract chapters from PDF, MOBI, and AZW3 files into individual numbered markdown files. Mirrors the epub-chapter-extractor pattern for non-EPUB formats.

Dependencies

  • PDF: pymupdf — auto-installed via --with pymupdf
  • Scanned PDF OCR fallback: requests (--with requests) + a Gemini key in $GEMINI_API_KEY / $GOOGLE_API_KEY (read from cornelius-internal/.env if unset)
  • MOBI / AZW3: calibre must be installed
    brew install --cask calibre
    

Single Book

cd $PROJECT_ROOT/.claude/skills/multi-format-book-extractor && \
uv run --with pymupdf --with requests python extract_book.py "/path/to/book.pdf" [output_dir]

If output_dir is omitted, creates a folder named after the file in the same directory.

Scanned / Image-Only PDFs (auto-OCR)

Some PDFs are pure page scans with no text layerpymupdf extracts nothing and would silently write empty files. extract_book.py now samples the text layer first (_has_text_layer) and, when a PDF looks image-only, automatically routes it to Gemini 2.5 Flash OCR (ocr_pdf.py).

  • Renders each page to PNG (~180 DPI), batches pages per API call, transcribes verbatim to Markdown (preserves verse line breaks, Sanskrit/Tibetan diacritics, footnotes), and writes NN_pages-S-E.md chunk files.
  • Resumable: re-running skips chunk files already written (≥200 chars), so an interrupted long book picks up where it left off.
  • Cost is ~$0.002/page on Flash (a 300-page book ≈ $0.60).

Run OCR directly (e.g. to tune params or force it):

cd $PROJECT_ROOT/.claude/skills/multi-format-book-extractor && \
uv run --with pymupdf --with requests python ocr_pdf.py "/path/to/scan.pdf" [output_dir] \
  [--model gemini-2.5-flash] [--dpi 180] [--pages-per-call 5] [--pages-per-file 20] [--concurrency 6]

Batch Extraction (Parallel)

Extract all PDFs, MOBIs, and AZW3s from a directory in parallel:

Read the full file on GitHub · 95 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 95 lines · 75 tokens per session scan A 0bfbe65c3115

Subscribe to this mod's changes

multi-format-book-extractor is a skill published in the GitHub repository Abilityai/cornelius (105 stars, last pushed 11d ago), licensed MIT. It adds 75 tokens to every session and 993 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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