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.
npx skills add jykim/claude-obsidian-skills --skill epub-to-markdowngit clone --depth 1 https://github.com/jykim/claude-obsidian-skillsWrote 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.
[](https://agentmods.dev/skills/jykim/claude-obsidian-skills/epub-to-markdown)<a href="https://agentmods.dev/skills/jykim/claude-obsidian-skills/epub-to-markdown"><img src="https://agentmods.dev/badge/skills/jykim/claude-obsidian-skills/epub-to-markdown/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/jykim/claude-obsidian-skills/epub-to-markdown"><img src="https://agentmods.dev/badge/skills/jykim/claude-obsidian-skills/epub-to-markdown.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00541 |
| Opus 5 | $0.00000 | $0.00270 |
| Sonnet 5 | $0.00000 | $0.00108 |
| Haiku 4.5 | $0.00000 | $0.00054 |
Grade A, and why
epub-to-markdown 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 13d 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.
How it starts
The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
EPUB to Markdown Skill
Convert EPUB files to well-formatted single markdown files with images extracted.
Usage
python3 epub_to_markdown.py "<epub_path>" -o "<output_path>"
Features
- Metadata extraction: title, author, language, publisher, publication date
- TOC parsing: Extracts table of contents with hierarchy
- HTML to Markdown: Converts chapter HTML using html2text
- Heading preservation: Maintains H1-H6 hierarchy
- Image extraction: Extracts images to
_files_/folder with book prefix - Single file output: All chapters in one markdown file
Output Structure
output_dir/
├── book.epub # Original file
├── book.md # Extracted markdown
└── _files_/ # Images folder
├── BookTitle_cover.jpg
├── BookTitle_figure1.png
└── ...
Image Prefix
Images are extracted with a book prefix derived from the title:
- Title: "Die Empty: Unleash Your Best Work Every Day"
- Prefix:
DieEmptyUnleash(first 3 words, special chars removed) - Image:
_files_/DieEmptyUnleash_cover.jpg
This prevents filename collisions when extracting multiple books to the same folder.
Output Format
---
title: {from metadata}
author: {from metadata}
language: {from metadata}
source_file: original.epub
source_type: epub
extracted: YYYY-MM-DD HH:MM:SS
status: extracted
---
# {Book Title}
## Table of Contents
- Chapter 1
- Chapter 2
...
---
## Chapter 1
{content with  links}
---
## Chapter 2
{content}
Dependencies
pip install ebooklib beautifulsoup4 html2text
Or use requirements.txt:
pip install -r requirements.txt
Options
| Flag | Description |
|---|---|
-o, --output |
Output markdown file path (default: same as epub with .md) |
-q, --quiet |
Suppress progress messages |
Limitations
- DRM-protected EPUBs: Cannot be extracted (will fail with error)
- Complex formatting: May simplify to plain text
- Large EPUBs: May take time for books with many chapters/images
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 13d ago First seen · 97 lines · 0 tokens per session scan A 6e105f5b0c9c
epub-to-markdown is a skill published in the GitHub repository jykim/claude-obsidian-skills (50 stars, last pushed 20d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 541 tokens. 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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