[GUI Plugin] ChapterPal Sync

[ChapterPal]

ChapterPal Sync

Select books in Calibre and sync them to your private ChapterPal My Library for conversational reading.

Requirements

• Calibre 7.0.0 or later on Windows, macOS or Linux. Tested on macOS with Calibre 9.17.0; Windows and Linux have not been validated.
• A paid ChapterPal account at ChapterPal. The plugin source itself is free software under GPL-3.0-or-later.
• DRM-free books. Non-EPUB formats are converted to EPUB with Calibre's bundled conversion tools. Scanned PDFs require OCR, which the plugin does not provide.

What it does

• Connects using the ChapterPal account signed in through your browser. No password or refresh token is stored by the plugin.
• Converts selected books locally using libraries bundled with Calibre; no separate Pandoc, Python or command-line tools are required.
• Uploads the converted content, images and metadata to your ChapterPal account. Books remain private. Repeated sync updates the same book.
• Retains source chapter structure, code, tables, images and supported MathML. This is a structural converter, not a full browser layout engine; unsupported content can cause an explicit conversion error.
• Uses Calibre's built-in plugin updater. ChapterPal → Manage plugin updates opens the updater. Catalog update notifications become available after a moderator adds this plugin to the index.

Installation
Download the ZIP attached to this first post. In Calibre, use Preferences → Plugins → Load plugin from file, select the ZIP, restart, and add ChapterPal through Preferences → Toolbars & menus. Once this plugin is indexed, it can also be installed through Preferences → Plugins → Get new plugins → ChapterPal Sync.

Usage
Choose ChapterPal → Connect ChapterPal account, confirm the connection in your browser, select books, then choose ChapterPal → Sync selected books. Reconnect after Calibre restarts or the current session expires. To apply a newer converter to existing books, select and sync them again.

Privacy and source
Conversion happens locally. Sync uploads the selected books' content, cover, images and metadata to the connected ChapterPal account. The attached ZIP includes the Python source and GPL license. Please use this thread for plugin support and reproducible bug reports. Do not attach copyrighted books without permission or include access tokens in reports.

Version History

Spoiler:

1.0.1 — 2026-11-03: Add a menu action for Calibre's built-in plugin updater and prevent updating during an active sync. Prepare versioned distribution.
1.0.0 — 2026-11-02: Initial account connection, local conversion and selected-book sync.