# Library: book price comparison

> Free, no-login tool at https://library.mncoleman.com to find a book by title, author, or ISBN and compare used and new prices from online booksellers (item + shipping to the US, in USD), plus search links to other stores. The same data is available as a JSON API with CORS. Library is also a home-library catalog app: scan ISBNs, record which shelf each book is on, estimate what the collection is worth, and lend books (Full plan).

Prices are cached per ISBN and refreshed when older than 12 hours; every response carries its "as of" time. Some links are affiliate links: if you buy through them I may earn a commission, at no extra cost to you. Prices and availability change; check the seller before you buy.

## Tool

- [Book price search](https://library.mncoleman.com/book-prices): search page; `https://library.mncoleman.com/book-prices?q={title, author, or ISBN}` (an ISBN redirects straight to the book).
- Book pages: `https://library.mncoleman.com/book/{isbn13}/{slug}` (any slug, or none, redirects to the canonical one). Each page embeds schema.org Book/Product JSON-LD with an AggregateOffer, and links its JSON via <link rel="alternate" type="application/json">. Requesting a book page with `Accept: application/json` returns the JSON directly.

## API

- [OpenAPI 3.1 spec](https://library.mncoleman.com/openapi.json)
- [Full API notes for agents](https://library.mncoleman.com/llms-full.txt)
- `GET https://library.mncoleman.com/api/v1/books/search?q={query}&limit={1-20}`: matching editions with ISBN-13s.
- `GET https://library.mncoleman.com/api/v1/books/{isbn}`: metadata + cached price summary (ISBN-10 or ISBN-13).
- `GET https://library.mncoleman.com/api/v1/books/{isbn}/prices`: every offer, cheapest first, with seller links; used/new lowest and median.

## Optional

- [Home library app](https://library.mncoleman.com/): catalog your own books by scanning ISBN barcodes; free for up to 100 books.
- [Features](https://library.mncoleman.com/features): screenshots of scanning, shelf locations, book values, and lending.
- [Pricing](https://library.mncoleman.com/pricing)
- [Terms](https://mncoleman.com/terms/#library) · [Privacy](https://mncoleman.com/privacy/#library)