# SiteCheck Book Lookup

> SiteCheck Book Lookup is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-16).

Looks up book metadata by ISBN, title, or author using the Open Library API, returning edition details, cover images, subjects, publishers, and more.

## Facts

- Endpoint: GET https://api.sitecheck-api.workers.dev/api/books?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-book-lookup-aa3805c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ljDNm-H2LI7x2StCDLJX3

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sitecheck-book-lookup-aa3805c8
```

Example prompt: Can you look up the book details for ISBN 9780140328721, including the cover image, publisher, authors, and how many editions exist?

## When to prefer this

Use this endpoint when you need structured bibliographic data for a book identified by ISBN, title, or author — especially when you need cover images, publisher history, edition counts, or Open Library/Wikidata identifiers. Prefer this over general web search when you want clean, structured library data rather than scraped text. Best suited for agents building reading lists, cataloging books, enriching product databases, or validating book metadata.

## Known failure modes

- ISBN not found in Open Library — returns empty books array
- Invalid ISBN format — may return no results or unrelated results
- Author/title search with too-common terms returns irrelevant results
- Open Library API unavailable — upstream timeout or error
- Limit parameter out of range (must be 1–20) may return default count
- Missing required input object causes validation error

## How this service works

Book lookup by ISBN (checked before the call) or by title and/or author: title, subtitle, authors, publishers, first publish year, median page count, ISBN-10 and ISBN-13 of the matching edition, languages, subjects, cover image URL, and the Open Library work and Wikidata ids. Data from Open Library (CC0). A title with no match is a 404, not charged. Up to 20 results.

## Output

Returns a JSON object containing a list of matching books with title, authors, cover URL, edition count, subjects, languages, page count, publishers, Wikidata IDs, edition ISBNs, Open Library work ID, and first publish year. Also includes a specific edition object (when ISBN is provided) with ISBN-10, ISBN-13, publish date, and edition-specific cover URL, plus the query parameters used and a checkedAt timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "isbn": {
       "type": "string",
       "description": "ISBN-10 or ISBN-13 with or without hyphens (optional)"
      },
      "limit": {
       "type": "string",
       "description": "Results, 1 to 20, default 5"
      },
      "title": {
       "type": "string",
       "description": "Title words, up to 200 characters (optional)"
      },
      "author": {
       "type": "string",
       "description": "Author name, up to 200 characters (optional)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "books": [
   {
    "title": "Fantastic Mr Fox",
    "authors": [
     "Roald Dahl"
    ],
    "coverUrl": "https://covers.openlibrary.org/b/id/6498519-L.jpg",
    "editions": 161,
    "subjects": [
     "Animals",
     "Hunger",
     "Open Library Staff Picks"
    ],
    "subtitle": null,
    "languages": [
     "jpn",
     "sco",
     "ita"
    ],
    "pageCount": 96,
    "publishers": [
     "Zemorah-Bitan",
     "Puffin Audiobooks",
     "SUD-AGUILA"
    ],
    "wikidataIds": [
     "Q126696579"
    ],
    "editionIsbns": [
     "9789575456108",
     "9780001006904",
     "0001031902"
    ],
    "openLibraryWork": "/works/OL45804W",
    "firstPublishYear": 1970,
    "editionIsbnsTotal": 276
   }
  ],
  "count": 1,
  "query": {
   "isbn": "9780140328721"
  },
  "source": "Open Library search API (openlibrary.org, data CC0)",
  "edition": {
   "pages": 96,
   "title": "Fantastic Mr. Fox",
   "isbn10": "0140328726",
   "isbn13": "9780140328721",
   "coverUrl": "https://covers.openlibrary.org/b/id/15152634-L.jpg",
   "languages": [
    "eng"
   ],
   "publishers": [
    "Puffin"
   ],
   "publishDate": "October 1, 1988",
   "openLibraryEdition": "/books/OL7353617M"
  },
  "checkedAt": "2026-10-15T15:14:30.074Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-book-lookup-aa3805c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)