Book & ISBN Catalog — bulk metadata lookup from Open Library + Gutenberg

Unofficial. This Actor is not affiliated with, endorsed by, or sponsored by the Internet Archive / Open Library, Project Gutenberg, or the Gutendex project. Those names are used only to describe the public, openly-licensed data sources this Actor reads. It is an independent tool built on their public APIs.

Turn a list of ISBNs, titles or authors into structured book records. Feed it a spreadsheet column of ISBNs and get back title, author, publisher, publication year, page count, subjects, cover art and canonical Open Library keys — plus, for public-domain works, direct Project Gutenberg download links and a real popularity number.

What it is good for

• Retail / marketplace catalog enrichment — a used-book or marketplace seller with ISBNs and nothing else gets a full listing's worth of metadata per row.
• Library and archive reconciliation — match local holdings against Open Library's canonical work keys.
• Public-domain sourcing — Gutendex records carry download_count, an actual demand signal for which public-domain titles people read, and direct epub/text URLs.
• Deduplication — resolve many editions to one work key.

Sources. Open Library (Internet Archive), CC0 metadata; Project Gutenberg via Gutendex, public domain. Both free, open, and cited on every row via source.

Verified sample records, verbatim:

{"title":"The hobbit","subtitle":"or There and back again","authors":["J.R.R. Tolkien"],
 "publishers":["HarperCollins"],"publishDate":"2020","numberOfPages":300,
 "openLibraryKey":"/works/OL27482W","query":"9780261103283","resolved":true}

{"title":"Foundation","authors":["Isaac Asimov"],"publishers":["Spectra","Bantam Books"],
 "publishDate":"October 1, 1991","numberOfPages":320,"openLibraryKey":"/works/OL46125W",
 "gutenbergId":23692,"gutenbergDownloadCount":3396,"query":"9780553293357","resolved":true}

The second row shows the Gutenberg join: the same work matched in Project Gutenberg, carrying its public-domain download links and a real download_count.

A note on upstream data quality. Open Library is a community/MARC-imported catalog, and some records are filed under malformed ISBNs. The Actor reports what Open Library publishes rather than second-guessing it, so a syntactically invalid ISBN can still return a record. Treat openLibraryKey as the trustworthy identifier, not the queried ISBN.

Input

Field	Type	Default	Notes
isbns	string[]	[]	ISBN-10 or ISBN-13, hyphens optional. Most precise input.
titles	string[]	[]	Free-text title search against Open Library.
authors	string[]	[]	Free-text author search.
includeGutenberg	boolean	true	Also query Gutendex for a public-domain match and attach download links + download_count.
limit	integer	10	Max results per title/author query (1–100).
language	string	""	Optional ISO-639 filter, e.g. eng. Blank = no filter.
maxConcurrency	integer	2	Low on purpose — Open Library throttles. See below.

Output

source, title, subtitle, authors[], isbn10[], isbn13[], publishers[], publishDate,
firstPublishYear, numberOfPages, subjects[], languages[], coverUrl, openLibraryKey,
gutenbergId, gutenbergDownloadCount, gutenbergFormats{}, queriedBy, query, scrapedAt

Rows that could not be resolved are emitted with resolved: false and the original query rather than dropped — a silent gap in an enrichment job is worse than an explicit miss.

Throughput — the operational catch

Measured with a 30-request burst:

• openlibrary.org/search.json: 27× 200, 2× 429, 1× ECONNRESET, median 1,764 ms.
• gutendex.com/books: 30× 301 (redirect — the Actor follows redirects; not a failure).

Open Library throttles and is slow. maxConcurrency defaults to 2 and the Actor backs off on 429. A 1,000-ISBN job is minutes, not seconds, and this listing says so rather than letting you discover it after paying.

Responsible use

Public, openly-licensed data only. Two open bibliographic APIs over plain HTTPS GET. No key, no account, no session, no CAPTCHA solving, no headless browser, no proxy rotation. Open Library metadata is released CC0; Project Gutenberg texts are public domain in the US.

No personal data of any kind. No borrower records, no user lists, no reading history. Open Library's /account, /borrow and lending endpoints are never touched.

Rate limiting. Concurrency defaults to 2 — the measured minimum, not a courtesy — and the Actor backs off on 429 rather than retrying hard.