With eBay API you communicate directly with the eBay database in XML format. By using the API, your application can provide a custom interface, functionality and specialized operations not otherwise afforded by the eBay interface. Because the API is not dependent on the eBay user interface, it allows you to create stable, custom functionality and interfaces that best meet your business needs. After joining the Developers Program, you will have access to the Developer Zone, a password-protected Web site for members only. The Developer Zone is the primary source for technical documentation and specifications, DTD files that define the XML input and output for the API, tools for creating and certifying your application and a full suite of additional technical resources.
Signup at http://developer.ebay.com Complete and confirm your application
Logon to the My Account page.
Your AppID should look similar to this xxxinxal-0092-4xxf-axx1-40xxx17exxx9

