canonical: https://jentic.com/apis/openlibrary.org/openlibrary # Open Library API The Open Library API looks up books, works, authors, subjects, and cover images from the Open Library collection by identifier or free-text search. It resolves an ISBN or Open Library ID to a full bibliographic record, returns an author profile and the works attributed to them, lists the works filed under a subject, and serves cover artwork at several sizes. Search endpoints return ranked matches for book titles and author names as JSON. ## For AI agents Search Open Library for books and authors, resolve ISBNs and Open Library IDs to bibliographic records, list works by subject, and fetch cover images. No API key required. ## Scope Does not handle ebook lending, user reading logs, or book purchases. Use for book, author, and bibliographic data lookup only. ## Capabilities - Search the book collection by title, author, or keyword - Search for authors by name and read their attributed works - Resolve an ISBN to a full book record - Fetch a book edition, work, or author by its Open Library ID - List the works filed under a given subject - Retrieve cover artwork for a book at small, medium, or large size ## Use cases ### AI Agent Book Lookup An AI agent building a reading list or enriching a citation can resolve a title or ISBN to a complete bibliographic record through Jentic. The agent searches by intent, passes the identifier or query, and receives the matching book, work, or author record without the developer reading the Open Library reference docs or handling any key, since the API is public. Example prompt: Call GET `/isbn/9780140328721` to resolve the ISBN to its Open Library edition record ### Collection Search and Discovery Reading apps and recommendation tools let users find books by title, author, or keyword. The search endpoint returns ranked matches with their Open Library IDs, which the app then expands into full edition and work records to display covers, descriptions, and publication details. Example prompt: Call GET /search.json with a title query, then read the matching work IDs from the results ### Author and Subject Browsing Library catalogs and literary sites build author pages and subject shelves. The author endpoint returns a profile, the author-works endpoint lists their titles, and the subject endpoint returns the works filed under a topic, so an agent can assemble a browsable collection around any author or theme. Example prompt: Call GET `/authors/OL23919A/works.json` to list the works attributed to that author ## Key endpoints | Method | Path | Description | | --- | --- | --- | | GET | `/search.json` | Search books by title, author, or keyword | | GET | `/search/authors.json` | Search for authors by name | | GET | `/isbn/{isbn}` | Resolve an ISBN to a book edition | | GET | `/books/{olid}` | Get a book edition by Open Library ID | | GET | `/works/{olid}` | Get a work by Open Library ID | | GET | `/authors/{olid}.json` | Get an author by Open Library ID | | GET | `/subjects/{subject}.json` | List works filed under a subject | | GET | `/covers/{key_type}/{value}-{size}.jpg` | Get a cover image at a given size | ## Key resources - **Search** — Ranked book and author search returning Open Library IDs - **Books and Works** — Edition, work, and ISBN record lookups by identifier - **Authors and Subjects** — Author profiles, their works, and works filed under a subject - **Covers** — Cover artwork served at small, medium, and large sizes ## AI readiness This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use. - **Score:** 47 / 100 - **Maturity:** Foundational - **Dimensions:** - Foundational Compliance: 100 / 100 - Developer Experience & Jentic Compatibility: 57 / 100 - AI-Readiness & Agent Experience: 41 / 100 - Agent Usability: 94 / 100 - Security: 100 / 100 - AI Discoverability: 14 / 100 - **View full report:** https://jentic.com/apis/openlibrary.org/openlibrary/scorecard - **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/ - **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview ### Score it yourself Every API in the directory is allowlisted, so you can re-score it with no key required. - **Score your own API:** https://jentic.com/scorecard.md - **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md ```sh npx @jentic/api-scorecard-cli score ``` ## Why Jentic - **Setup:** The Open Library API needs no API key, so there is nothing to wire up before your agent can call it. Through Jentic you install once, import Open Library from the API Directory, and your agent searches books and reads records straight away. - **Permission scoping:** This API is read-only, so a rule can bound your agent to the lookups it needs, such as book search and ISBN resolution, and exclude the rest. You choose the operation set, so the agent can read bibliographic data but cannot reach anything you did not grant. - **Credential handling:** Open Library needs no API key or token, so there is no secret to store or inject. Jentic still runs every call from your own self-hosted instance, so execution stays on your infrastructure. - **Discovery method:** Agents search Jentic by intent such as 'look up a book by ISBN' or 'search for an author', and Jentic returns the matching Open Library operation with its input schema so the agent calls the right endpoint without reading the reference docs. ## Related APIs - **ISBNdb** — Commercial book and ISBN database with publisher and pricing metadata - **Google Books** — Google Books volume search and metadata with preview content - **Google Programmable Search** — General web search to augment book discovery beyond the collection ## FAQ ### What authentication does the Open Library API use? The Open Library API requires no authentication; its endpoints are public per the OpenAPI spec. Through Jentic the calls still run from your own self-hosted instance, so you keep an audit log of everything the agent requests. ### Can I resolve an ISBN to book data with the Open Library API? Yes. The ISBN endpoint returns the matching edition record, and you can follow its work and author IDs to pull the full bibliographic detail. Free-text search is available when you only have a title or author name. ### What are the rate limits for the Open Library API? The OpenAPI spec does not specify rate limits. Open Library asks clients to call the API responsibly and documents current guidance at https://openlibrary.org/developers/api. ### How do I search Open Library through Jentic? Install Jentic One with `curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh`, then import Open Library from the API Directory. Your agent searches for an intent such as 'search books by title', and Jentic returns the matching operation with its input schema. There is no key to configure. To run it on your own infrastructure, install Jentic One from its GitHub repo. ### Is there an Open Library MCP server? You do not need an MCP server to give your agent the Open Library API. Jentic connects it directly from the API Directory: import the API and your agent calls the search and lookup operations on demand, which keeps your agent's context free of an extra server's tool definitions. ### Can I limit what my agent is allowed to do with the Open Library API? Yes. Every operation is a read, so you can allow only the ones the agent needs, such as book search and ISBN lookup, while leaving out author or subject browsing. Because you run Jentic One yourself, the agent holds no access beyond the read operations you grant, and every call is logged.