epub-creator_skill

Overview

This skill creates production-quality EPUB 3 ebooks from Markdown and image sources with automated QA, formatting fixes, and validation. It normalizes Markdown quirks, optimizes and validates images and covers, generates a nested table of contents, and assembles validated EPUB output. The process is designed for repeatable, publishable results and supports frontmatter metadata extraction and robust XHTML conversion.

How this skill works

The tool pre-validates inputs, fixes common Markdown issues (headings, unclosed emphasis, broken links), and inspects images and cover art for size, format, and aspect ratio. It extracts frontmatter, determines chapter titles, converts Markdown to clean XHTML with accessibility fixes, and builds a hierarchical TOC with anchors. Finally it assembles the EPUB package, applies professional CSS, runs validation (epubcheck optional), and reports issues for delivery.

When to use it

• Publishing an ebook from a directory of Markdown chapters and images
• Converting technical or narrative Markdown into a validated EPUB 3 package
• Compiling multiple chapters into a single, release-ready ebook
• Automating image optimization and cover validation before publishing
• Integrating EPUB generation into a CI/CD pipeline for book publishing

Best practices

• Keep a metadata.yaml or YAML frontmatter in each chapter for consistent titles and author data
• Use descriptive alt text for images; the converter will add placeholders when missing
• Provide a high-resolution cover (recommended ~1600x2400, minimum ~1400x2100) for best display
• Run epubcheck in CI to catch validation issues before release (install via package manager or Python wrapper)
• Limit large images (auto-resize above thresholds) and prefer JPEG/PNG to avoid format conversions

Example use cases

• Turn a course of Markdown lecture notes and figures into a single EPUB for students
• Publish a fiction or non-fiction manuscript authored in Markdown with automated TOC and cover handling
• Convert a technical handbook with code blocks and tables into accessible, styled XHTML for EPUB
• Batch process multiple chapters from a documentation repo and produce a validated release artifact
• Use as a CI step to produce EPUBs from a Git tag and attach validated builds to releases