The eBay Trading API offers secure, authenticated access to private eBay data. Developers can use the eBay Trading API to build applications such as selling and post-sales management applications, manage user information, and initiate item purchase flow on eBay.
The API uses SOAP and HTTP protocols to return responses in XML, and includes .Net, Java, and PHP API SDK's. There are also [[https://developer.ebay.com/devzone/xml/docs/reference/ebay/index.html tutorials]] for using the Trading API with PHP, Perl, C#, and Java.
eBay has announced the availability of two new Sell and Buy APIs; the Taxonomy API and Buy Marketing API. The company also announced some of the existing Sell and Buy APIs have been updated to add new features. These APIs will eventually replace the eBay’s legacy Trading API..