Open Library API
The Internet Archive's open book catalogue: search by title/author/ISBN, resolve works and editions, and pull cover images by ISBN/OLID, all keyless.
Open Library (run by the Internet Archive) is a keyless JSON API covering tens of millions of books. The Search API returns ranked docs with title, author names/keys, first publish year, edition counts, ISBNs, ebook-access flags, and Internet Archive identifiers. Works (/works/{id}.json) and editions (/books/{id}.json) endpoints give canonical records, and the separate Covers service returns book-cover images by ISBN, OLID, or cover ID. Great for metadata enrichment, ISBN lookup, and displaying covers without licensing fees.
Free tier
Free, no key required.Rate limits
No fixed published quota on search, but Open Library asks for a descriptive User-Agent and reasonable use; the Covers endpoint is limited to ~100 requests/IP per 5 minutes when querying by ISBN/OLID (403 over the cap). Lookups by cover ID are NOT capped.Auth
No keyBase URL
https://openlibrary.orgWhat you'd build with it
- ISBN to title/author/cover enrichment for a library or catalogue
- Display book covers via covers.openlibrary.org without licensing
- Look up works, editions, and subject classifications
- Cross-reference a reading list against Internet Archive availability
Key endpoints
- GET
/search.jsonFull-text catalogue search; ?q=, ?title=, ?author=, ?fields=, ?limit=, ?page= - GET
/works/{olid}.jsonFetch a canonical work record (title, description, authors, subjects) - GET
/books/{olid}.jsonFetch a specific edition record - GET
/isbn/{isbn}.jsonResolve an edition by ISBN
Members get the runnable recipe
Sign in free to copy the example request, see a sample response, and read the gotchas.