Markitdown
ImCa0/just-laws
Convert files and office documents to Markdown. An agent skill from ImCa0/just-laws.
Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files.
Install Multi Format Book Extractor
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install Abilityai/cornelius multi-format-book-extractor --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .claude/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .claude/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractorType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install Abilityai/cornelius multi-format-book-extractor --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .agents/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .agents/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install Abilityai/cornelius multi-format-book-extractor --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .cursor/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .cursor/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/Abilityai/cornelius.git --path .claude/skills/multi-format-book-extractor--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install Abilityai/cornelius multi-format-book-extractor --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .gemini/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .gemini/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install Abilityai/cornelius multi-format-book-extractorInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .github/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .github/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install Abilityai/cornelius multi-format-book-extractor --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/Abilityai/cornelius.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/multi-format-book-extractor .opencode/skills/multi-format-book-extractor && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "multi-format-book-extractor" agent skill from https://github.com/Abilityai/cornelius/tree/main/.claude/skills/multi-format-book-extractor into .opencode/skills/multi-format-book-extractor/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "multi-format-book-extractor", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
multi-format-book-extractor- GitHub stars
- 109
- Token cost
- ~872 tokens
- SKILL.md length
- 266 words
- Files
- 1
- Skills in repo
- 56
- Repo updated
- First seen
- Licence
- MIT
At a glance
Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files.
- Extracting non-EPUB books
- SKILL.md covers Dependencies, Single Book, Scanned / Image-Only PDFs… and Batch Extraction (Parallel), plus 2 more sections
- Calls uv and brew; needs GEMINI_API_KEY and GOOGLE_API_KEY
- Tasks that involve PDF
What it does
Multi Format Book Extractor is an agent skill from Abilityai/cornelius. Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files. Use when extracting non-EPUB books. PDF uses pymupdf with TOC-based chapter splitting and auto-OCR fallback (Gemini) for scanned/image-only PDFs; MOBI/AZW3 routes through calibre then epub-chapter-extractor.
Its SKILL.md is about 870 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Documents & Office, covering PDF. The repository describes itself as: AI-powered second brain template for Claude Code + Obsidian. The licence is MIT.
When your agent uses it
- Extracting non-EPUB books
- Tasks that involve PDF
Example prompts
- “/multi-format-book-extractor”
Requirements
- Python 3
- A credential in GEMINI_API_KEY
- A credential in GOOGLE_API_KEY
- Pre-approved tools (allowed-tools): Bash
What it can do on your machine
Read from SKILL.md and the folder at commit fd5e9a4. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
Bash
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
uvbrew
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
calibre-ebook.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names these keys or tokens, usually read from environment variables:
GEMINI_API_KEYGOOGLE_API_KEY
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Multi Format Book Extractor loads about 872 tokens when it runs. Until then it costs about 80 tokens; SKILL.md has 266 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NoteMentions a .env fileSKILL.md:17
_API_KEY` (read from `cornelius-internal/.env` if unset) - NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Bash
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from Abilityai/cornelius at commit fd5e9a4, republished under its MIT licence (© Abilityai). 266 words, ~872 tokens.
Download SKILL.mdSave it as
.claude/skills/multi-format-book-extractor/SKILL.md (or your agent's skills folder).- name
- multi-format-book-extractor
- description
- Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files. Use when extracting non-EPUB books. PDF uses pymupdf with TOC-based chapter splitting and auto-OCR fallback (Gemini) for scanned/image-only PDFs; MOBI/AZW3 routes through calibre then epub-chapter-extractor.
- allowed-tools
- Bash
- user-invocable
- true
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 fromcornelius-internal/.envif unset) - MOBI / AZW3: calibre must be installed
bash 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 layer — pymupdf 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.mdchunk 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 $PROJECT_ROOT/.claude/skills/multi-format-book-extractor && \
uv run --with pymupdf --with requests python ocr_pdf.py "/path/to/scan.pdf" [output_dir] \
[--model gemini-2.5-flash] [--dpi 180] [--pages-per-call 5] [--pages-per-file 20] [--concurrency 6]Batch Extraction (Parallel)
Extract all PDFs, MOBIs, and AZW3s from a directory in parallel:
SKILL="$PROJECT_ROOT/.claude/skills/multi-format-book-extractor"
UVX="uv"
DIR="/path/to/books"
for book in "$DIR"/*.{pdf,mobi,azw3}; do
[ -f "$book" ] || continue
stem="${book%.*}"
[ -d "$stem" ] && echo "Skipping: $(basename "$book") (already extracted)" && continue
echo "Starting: $(basename "$book")"
(cd "$SKILL" && $UVX run --with pymupdf --with requests python extract_book.py "$book") &
done
wait
echo "All done"Output Format
Each book gets a subfolder named after the file (without extension):
book-name/
├── 01_introduction.md
├── 02_chapter-one.md
└── ...- PDF with TOC: one file per chapter (uses level-1 TOC; falls through to level-2 if < 5 top-level entries, e.g. books structured as Parts)
- PDF without TOC: 20-page chunks (
01_pages-1-20.md, etc.) - Scanned / image-only PDF: auto-routed to Gemini OCR → 20-page chunks (
01_pages-1-20.md) with<!-- page N -->markers - MOBI / AZW3: same output quality as epub-chapter-extractor (converts via calibre first)
After Extraction
open /path/to/books/© Abilityai, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .claude/skills/multi-format-book-extractor of Abilityai/cornelius.
Open the folder on GitHubat commit fd5e9a4
Compare with similar skills
Multi Format Book Extractor next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Multi Format Book Extractor this skillAbilityai/cornelius | 109 | — | ~872 | Automated safety check: Notes | MIT | |
| MarkitdownImCa0/just-laws | 781 | 14 repos | ~3.2k | Automated safety check: Notes | MIT | |
| Gzh Designisjiamu/gzh-design-skill | 3.9k | 1 repos | ~2.2k | Automated safety check: Pass | AGPL-3.0 | |
| GenOffice Document CLIgenspark-ai/genoffice | 8.8k | — | ~19k | Automated safety check: Pass | Apache-2.0 | |
| Harness Book Best Practicewquguru/harness-books | 3.2k | — | ~4.1k | Automated safety check: Pass | None | |
| Bookforge Korean Ebook PDF Makergongnyang/bookforge | 314 | 1 repos | ~1.7k | Automated safety check: Pass | MIT |
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Categories
Questions about Multi Format Book Extractor
What does Multi Format Book Extractor do?
Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files. Multi Format Book Extractor is an agent skill from Abilityai/cornelius. Extract chapters from PDF, MOBI, and AZW3 book files into individual markdown files.
When should I use Multi Format Book Extractor?
Multi Format Book Extractor fits situations like: extracting non-EPUB books; tasks that involve PDF.
How do I install Multi Format Book Extractor in Claude Code?
Run `npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a claude-code`. Or copy the skill folder (.claude/skills/multi-format-book-extractor in Abilityai/cornelius) into .claude/skills/multi-format-book-extractor in your project. Claude Code loads it when a task matches its description.
How do I install Multi Format Book Extractor in Codex?
Run `npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a codex`. Or copy the skill folder (.claude/skills/multi-format-book-extractor in Abilityai/cornelius) into .agents/skills/multi-format-book-extractor in your project. Codex loads it when a task matches its description.
Can I use Multi Format Book Extractor in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add Abilityai/cornelius --skill multi-format-book-extractor -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/multi-format-book-extractor, .gemini/skills/multi-format-book-extractor, .github/skills/multi-format-book-extractor and .opencode/skills/multi-format-book-extractor in your project.
What does Multi Format Book Extractor need to run?
Going by SKILL.md and its folder, Multi Format Book Extractor needs the command-line tools its instructions call (uv and brew) and credentials named GEMINI_API_KEY and GOOGLE_API_KEY. Our summary lists: Python 3; A credential in GEMINI_API_KEY; A credential in GOOGLE_API_KEY. Its frontmatter pre-approves these tools: Bash.
Does Multi Format Book Extractor access the network?
SKILL.md names 1 domain. As links in the text: calibre-ebook.com. This is read from the text; nothing was executed.
Is Multi Format Book Extractor safe to install?
Our automated static check of SKILL.md found notes only (mentions a .env file; pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.
What licence does Multi Format Book Extractor use?
Multi Format Book Extractor is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Multi Format Book Extractor use?
About 872 tokens (SKILL.md is roughly 3.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Multi Format Book Extractor?
Skills that share tags, products or a category with Multi Format Book Extractor: Markitdown (ImCa0/just-laws, 781 stars), Gzh Design (isjiamu/gzh-design-skill, 3.9k stars), GenOffice Document CLI (genspark-ai/genoffice, 8.8k stars) and Harness Book Best Practice (wquguru/harness-books, 3.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Multi Format Book Extractor?
Abilityai (a GitHub organization) maintains it in Abilityai/cornelius, which has 109 GitHub stars. The repository holds 56 skills in this directory. The repository was last updated on September 22, 2026.
Source: Abilityai/cornelius on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.