name

kindle-book

description

Convert markdown (.md) or plain text (.txt) files into Amazon KDP-ready book files: EPUB3 for Kindle digital publishing and a print-ready PDF for KDP paperback (6×9", 5×8", or custom trim). Use this skill whenever the user wants to: publish a book on Amazon Kindle, create an ebook from markdown, generate a KDP-ready EPUB or print PDF, self-publish a book, convert a manuscript to Kindle format, or make digital + print book files. Trigger even for partial phrases like "make it a Kindle book", "publish this as an ebook", "KDP files", "format my book for Amazon", or "I want to sell this on Kindle".

Kindle Book Skill

Converts MD/TXT manuscripts → EPUB3 (Kindle digital) + print-ready PDF (KDP paperback) using pandoc + XeLaTeX.

Quick Start

Read the user's source file(s) from /mnt/user-data/uploads/
Extract or ask for book metadata (see Metadata section)
Run scripts/build_kindle.py with appropriate flags
Present both output files to the user

Prerequisites Check

which pandoc xelatex python3

All three must be present. They are pre-installed in Claude's container.

Step 1: Extract Metadata

Parse YAML frontmatter from the MD file if present. If missing, ask the user for:

Field	Required	Default
`title`	✅	—
`author`	✅	—
`language`	✅	`en-US`
`publisher`	optional	—
`rights`	optional	—
`description`	optional	—
`trim_size`	optional	`6x9`
`cover_image`	optional	none

Supported trim sizes: 5x8, 6x9 (most popular), 8.5x11

YAML frontmatter format (tell user to add to top of MD file):

---
title: "My Book Title"
author: "Author Name"
language: en-US
publisher: "Publisher Name"
rights: "© 2025 Author Name. All rights reserved."
description: "One-line book description for metadata."
trim_size: "6x9"
cover_image: "cover.jpg"   # optional, path relative to manuscript
---

Step 2: Prepare the Manuscript

Heading Structure (critical for chapter splitting)

# Title → Book title (optional, can be in frontmatter)
# Chapter Name → Each # heading becomes a new chapter in EPUB
## Section → Sub-sections
### Sub-section → Sub-sub-sections

Markdown Features Fully Supported

Bold **text**, italic *text*
Block quotes > text
Ordered and unordered lists
Horizontal rules --- (scene breaks)
Images ![alt](path.jpg)
Tables

Common Issues to Fix Before Building

Remove any existing page numbers or headers from the source
Ensure each chapter starts with a # heading (not ##)
Images referenced must exist relative to the source file

Step 3: Build the Files

Run the build script:

python3 /path/to/skill/scripts/build_kindle.py \
  --input /mnt/user-data/uploads/manuscript.md \
  --output /mnt/user-data/outputs/ \
  --title "Book Title" \
  --author "Author Name" \
  --language en-US \
  --trim 6x9

Optional flags:

  --cover /mnt/user-data/uploads/cover.jpg   # EPUB cover image
  --publisher "Publisher Name"
  --rights "© 2025 Author"
  --description "Book tagline"
  --epub-only     # skip PDF
  --pdf-only      # skip EPUB
  --font-size 12  # body font size in pt (default: 12)

The script outputs:

<slug>_digital.epub — upload to KDP eBook section
<slug>_print.pdf — upload to KDP paperback interior section

Print PDF overflow prevention (built into the script):

Long code block lines are auto-wrapped to fit the trim size
Tables get proportional column widths via a lua filter
Inline monospace (code) text can break at hyphens/slashes
URLs break at any character via xurl
Global \sloppy + \emergencystretch prevents text overflow

Step 4: Verify Outputs

After building, tell the user:

For digital EPUB:

Upload to KDP → Kindle eBooks → Manuscript upload
KDP accepts EPUB3 directly
Preview in KDP's online previewer before publishing

For print PDF:

Upload to KDP → Paperback → Manuscript upload
Margins are set for the selected trim size
Page numbers are in the header (outside edge)
Bleed is NOT included (no full-bleed images)
Confirm page count matches KDP's estimate before ordering proof

Troubleshooting

Problem	Fix
`lmodern.sty not found`	Script uses custom template that bypasses lmodern — use `build_kindle.py`, not raw pandoc
`openBinaryFile: does not exist`	YAML `cover-image:` field is empty — remove it or set a valid path
Chapters not splitting in EPUB	Each chapter must start with `#` (H1), not `##`
Images missing in EPUB	Image paths must be relative to manuscript file location
PDF text too small	Use `--font-size 13` or `--font-size 14`
KDP "text outside margins" on tables	The build script uses a lua filter to auto-assign column widths — this should be automatic. If a specific table still overflows, shorten the cell content (especially inline code)
KDP "text outside margins" on code blocks	The build script wraps code lines to fit the trim size. If issues persist, check for very long strings without spaces (URLs, file paths) and manually add line breaks in the markdown
KDP "text outside margins" on inline code	The LaTeX template allows monospace to break at hyphens. For extremely long inline code strings, break them with spaces in the markdown
KDP "removed non-printable markup"	Normal — KDP strips hyperlinks from print PDFs since they're not clickable on paper. No action needed

KDP Upload Checklist (tell user)

eBook:

EPUB3 file uploaded
Cover image: JPG/TIFF, 2560×1600px minimum, 1.6:1 ratio
Preview on KDP previewer before publishing
Set DRM preference
Set pricing and territories

Paperback:

Interior PDF uploaded (this script's output)
Cover: use KDP Cover Calculator for spine width → upload separate PDF cover
Select matching trim size in KDP settings
Order a proof copy before going live

References

references/trim-sizes.md — KDP trim size margin specs for all sizes
assets/print-template.tex — LaTeX template used for print PDF
assets/epub-styles.css — CSS injected into EPUB
scripts/build_kindle.py — Main build script

Read references/trim-sizes.md if the user requests a non-standard trim size.