Caching Free LibraryThing Book Covers

LibraryThing did something amazing last Thursday: it made images of the covers of a million books available for anyone to use for free. This is way better than using Amazon.com’s book covers because you can display them without linking to Amazon. If you are a library or an independent book store, having links on your web site which can draw your patrons or customers to Amazon is not a particularly good thing. It is obviously better than a commercial book cover service because, well, it’s free.

Here is an example. I own a copy of 100 Great Fantasy Short, Short Stories. Since I am using a LibraryThing cover, I can legally link the image to the LibraryThing description (which I have done) or I could have linked it to my own LibraryThing catalog or to anything else I choose.

There are a couple of small potential problems and these prompted me to write a little caching script for the LibraryThing covers. First, you need to use your own developer key to obtain the covers from LibraryThing and there is a slight chance that you could exceed the maximum number of covers per day that LT is willing to provide to you. Second, since I am quite sure that this service will be very popular, LT’s servers could get a bit overburdened if everybody hits them for images.

The solution? Install my little LTcovers PHP script on your own web server. It is just a single file and needs a single directory in which it can store copies of the book cover images that you need. As your patrons/customers/users display covers on your web site, LTcovers will grab the images from LibraryThing and keep a local copy. Once configured, it needs no maintenance.

What do you need?

1. The ltcovers.zip script. Right-click on that link and “Save As” ltcovers.zip on your own web server. Unzip the file to extract ltcovers.php
2. Your own LibraryThing developer key. It’s free and you need to have your own.
3. You might want a 1×1 pixel transparent GIF image as a default image, in case you request a cover which LibraryThing does not have. You can download one from here. (Use “Save As” again.)

My LTcovers script is available for free under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

The images from LibraryThing are available under these terms, “You also agree to some very limited terms: You do not make LibraryThing cover images available to others in bulk. But you may cache bulk quantities of covers. Use does not involve or promote a LibraryThing competitor. If covers are fetched through an automatic process (eg., not by people hitting a web page), you may not fetch more than one cover per second.”

I hope that between LibraryThing and this script, you can save a few dollars (if you are now paying for a commercial book cover service) and provide a better experience for your web site visitors (if you are now linking to Amazon).

Shameless commercial plug: If you want to use LTcovers but cannot install it on your own web server, Hen’s Teeth Network will be glad to provide you with a small hosting account quite suitable for running it. We will even install LTcovers for free if you sign up for one of our hosting accounts.