The eBay API and SOAP

eBay’s auction site began in 1995 as a way for individuals to post items for sale to a global, Web-based community. As eBay grew into the most popular auction site (and one of the most popular e-commerce sites) on the Web, ISVs such as Andale and AuctionWatch.com began building e-commerce applications for businesses to automatically post items for auction on eBay’s sites. eBay, seeing the business-to-consumer market falter, encouraged such activity as a way to increase B2B activity to its largely consumer service. (eBay added its first B2B-specific exchange in Mar. 2000.) However, when eBay made changes to its site—for example, modifying the forms that sellers use to post auction listings—these third-party applications could break.

In addition, content-oriented sites wanted to incorporate relevant eBay auction listings into their sites to make them more compelling: a sports site could include auctions for sports memorabilia, for example.

In response, eBay announced the “eBay API” in Nov. 2000. Using this API, a third-party developer can create an eBay-enabled application on any platform capable of communicating over HTTP, the standard Web communications protocol. The application sends individual requests for information, such as a list of items being auctioned, in XML format, over HTTP, to a program running on dedicated servers at eBay. The requested data are returned as XML records to the application, which then makes them available to the end user. The API also provides functions for listing an item or submitting a bid.