After reflecting on the coming demise of xISBN, we decided to add an endpoint for free ebooks to the unglue.it API.

The API documentation is at https://unglue.it/api/help

With an API key, you can check if there’s a free ebook for any ISBN. ISBNs can be 10 or 13 digits, and can include dashes. This service returns all free-licensed ebooks for a work associated with an ISBN, and for each ebook includes information about file type, rights, and the provider hosting the file.

For example, here’s how to get a list of ebook files for “Homeland”.

JSON: https://unglue.it/api/v1/free/?isbn=9780765333698&format=json&api_key={your_api_key}&username={your_username}

{
 "meta": {"total_count": 3},
 "objects": [
    {"filetype": "pdf", "href": "/download_ebook/2576/", "provider": "Internet Archive", "rights": "CC BY-NC-ND"},
    {"filetype": "epub", "href": "/download_ebook/2577/", "provider": "Internet Archive", "rights": "CC BY-NC-ND"},
  {"filetype": "mobi", "href": "/download_ebook/2578/", "provider": "Internet Archive", "rights": "CC BY-NC-ND"}
    ]
 }

XML: https://unglue.it/api/v1/free/?isbn=9780765333698&format=xml&api_key={your_api_key}&username={your_username}

<response>
 <objects type="list">
 <object>
 <href>/download_ebook/2576/</href>
 <filetype>pdf</filetype>
 <provider>Internet Archive</provider>
 <rights>CC BY-NC-ND</rights>
 </object>
 <object>
 <href>/download_ebook/2577/</href>
 <filetype>epub</filetype>
 <provider>Internet Archive</provider>
 <rights>CC BY-NC-ND</rights>
 </object>
 <object>
 <href>/download_ebook/2578/</href>
 <filetype>mobi</filetype>
 <provider>Internet Archive</provider>
 <rights>CC BY-NC-ND</rights>
 </object>
 </objects>
 <meta type="hash"
 ><total_count type="integer">3</total_count>
 </meta>
</response>

We’ll soon be integrating Gitenberg ebooks into this feed, too.