How eBay Uses Metadata to Enhance Its Web Services

[mandy]

With a simple web service like a stock price lookup service, you can pass in a string representing the stock symbol and get back a decimal indicating its current price. Web services like these are easy to document and even with slightly more complex services, like an address validation service where you pass in multiple pieces of data, it is still relatively easy to document what data gets passed in and is returned by the service. However, for companies like eBay that have released sophisticated web services, the task of documenting those services is increasingly complex. This article describes how eBay tackled the problem of documenting its web services using structured metadata. In the end, our problems were solved by using the little-known XML Schema standard appinfo element...

The eBay Web Services schema defines the services that are exposed and the data types that are used when interacting with those services. Each service is referred to as a call, and there are calls that support operations such as listing an item, searching the eBay database, viewing My eBay data, and much more...

full article: http://www.xml.com/lpt/a/2005/09/28/ebay...vices.html