Your Amazon Marketplace Web Service (Amazon MWS) client applications should gracefully
handle changes to the reports and response elements that Amazon MWS returns, even without prior change
notification from Amazon.
Changes to reports returned by Amazon MWS
Build report parsers into your client applications that can gracefully handle the
following types of changes to the reports that Amazon MWS returns:
New fields in reports. Your client applications should handle new
fields in reports as they become available. These include new columns in
flat file reports and new elements in XML reports.
New field values in reports. Your client applications should handle
new field values in reports as they become available. These include new
column values in flat file reports and new element values in XML reports.
Important: If you choose to
use report XSDs published by Amazon to validate reports returned by Amazon MWS,
be sure to build error handling into your validation logic. Any report
validation included in your client application should be able to gracefully
handle new, unrecognized response elements or response element
Changes to Amazon MWS response elements
Build your client applications to gracefully handle the following types of changes to Amazon MWS responses:
- New response elements. Your client applications should handle new,
unrecognized response elements.
- New response element values. Your client applications should handle new,
unrecognized response element values.
What does it mean to "gracefully handle" changes? Here are some examples:
- Expect changes. At a minimum, ensure that your client applications do
not break when new response elements, response element values, report fields
or report field values are introduced by Amazon. Don’t code your client
applications to expect only certain elements, fields, and values.
- Log unrecognized elements, fields, or values. Keep a log of all unrecognized
elements, fields, or values returned by Amazon MWS. You can use this log to flag new
functionality that has been introduced by Amazon, and then update your
client application to take advantage of this functionality.
- Surface unrecognized elements, fields, or values. If Amazon MWS begins returning a report with a new
field, for example, you might devise a way to automatically surface the new
field values in your client application in a way that is useful to your
- Expect response elements in any order. Response elements can be returned in any
order within a structure. Ensure that your client applications do not depend
on the order in which response elements are returned by Amazon MWS.