[Metadata Plugin] OpenLibraryPlus Metadata

[dunhill]

This plugin was created to extend Calibre’s capabilities by identifying and completing book metadata directly from OpenLibrary.
Its main purpose is to allow adding works without ISBNs, using OpenLibrary’s own identifiers (e.g. OL25898225M, OL625575W).

Key Features
Identification via OpenLibrary codes:
Add older or ISBN-less books to Calibre using OpenLibrary identifiers (Works and Editions).

Rich metadata extraction:
The plugin automatically retrieves:
• Title
• Author(s)
• Publisher
• Publication date
• Language
• Tags/subjects
• Rating (when available)
• Cover image

Plugin Options
Custom identifiers:
Enter in Calibre’s Ids field:
Código
openlibrary:OL625575W
or the full OpenLibrary link.

Example Usage
Add a book without ISBN to Calibre.
In the Ids field, enter:
Código
openlibrary:OL25898225M
Run Download metadata.

The plugin will automatically fill in title, author, publisher, date, language, tags, and cover.

Installation
Download the attached .zip file.
In Calibre: Preferences → Plugins → Load plugin from file.
Restart Calibre.
Add the plugin button to the toolbar or context menu.

Requirements
Calibre 6.0 or higher
Internet connection to access OpenLibrary

Use this MobileRead thread for questions and suggestions.
Contribute improvements: the plugin is designed to grow with community input.

License
GNU General Public License v3 (GPL-3)

Version History

Spoiler:

Version 1.3.0 - 2026-04-19
Fix: Changed publication date format from datetime.date to datetime.datetime to prevent "type mismatch" errors when merging metadata with other sources.
Fix: Commas in tags/subjects are now replaced with hyphens to prevent Calibre from splitting a single tag into multiple entries.
Improvement: Enhanced OpenLibrary ID detection to handle identifiers with prefixes correctly.
Improvement: Minor internal code cleanup for better stability.

v1.2: Fixed syntax/indentation errors, improved fallback and visual consistency. Also search by ISBN

v1.1: Extended support for additional fields (publisher, language, tags, rating, cover).

v1.0: First public release.

[ARR8]

Thanks for the plugin. Two comments:
1. This isn't appearing in the plugin catalog because it isn't in the index thread.
2. I get errors trying to use alongside other metadata sources because it returns a datetime.date for the publication date instead of the datetime.datetime the others use, and Calibre refuses to mix the two types.

[ARR8]

Also, tags with commas in them get split up.

[dunhill]

Originally Posted by ARR8

Also, tags with commas in them get split up.

ARR8 Hi! Thank you very much for your feedback. You were absolutely right about the date format and the comma issue in tags.

I have just uploaded Version 1.3.0, which fixes both bugs:
The publication date now returns a datetime.datetime object, so it should play nicely with other metadata sources.
Commas in tags are now automatically replaced with hyphens to prevent them from being split.
Please let me know if it works for you now!

Regarding this issue: 1. It doesn't appear in the plugin catalog because it's not in the indexing thread.
A moderator must add it to the index.

[ARR8]

Thank you! Much better, appreciate the fixes. As for the index, I do believe you have to request for it to be added.

[theducks]

Originally Posted by dunhill

ARR8 Hi! Thank you very much for your feedback. You were absolutely right about the date format and the comma issue in tags.

I have just uploaded Version 1.3.0, which fixes both bugs:
The publication date now returns a datetime.datetime object, so it should play nicely with other metadata sources.
Commas in tags are now automatically replaced with hyphens to prevent them from being split.
Please let me know if it works for you now!

Regarding this issue: 1. It doesn't appear in the plugin catalog because it's not in the indexing thread.
A moderator must add it to the index.

@dunhill
Did you complete the form found in the firs post of Index of... and PM it to a forum Mod?

Notes for Forum Admins:
Spoiler:

[dunhill]

Originally Posted by theducks

@dunhill
Did you complete the form found in the firs post of Index of... and PM it to a forum Mod?

Notes for Forum Admins:
Spoiler:

I'll write it up now, thanks for the information.

[JSWolf]

Does Open Library actually return usable metadata that does not need manual intervention?