This document describes the protocol used by the Google Data APIs, including information about what a query looks like, what results look like, and so on.
For more information about the Google Data APIs, see the Google Data Developer's Guide document and the Protocol Guide.
Contents
- Audience
- Protocol details
- Additional resources
Audience
This document is intended for anyone wanting to understand the details of the XML format and protocol used by the Google Data APIs.
If you just want to write code that uses the Google Data client architecture
- coding using the protocol without using the provided Google Data messages using any programming language that lets you issue HTTP requests and parse XML-based responses.
Protocol details
This section describes the Google Data document format and query syntax.
Document format
Google Data, Google Data's default format. To request a response in RSS format, use the
/alt=rss/ parameter; for more information, see Query requests.
When you request data in RSS format, Google Data supplies a feed (or other representation of the resource) in RSS format. If there's no equivalent RSS property for a given Google Data property, Google Data uses the Atom property, labeling it with an appropriate namespace to indicate that it's an extension to RSS.
Note: Most Google Data Google Data feed:
The following table shows the elements of a Google Data search-results feed. Note that Google Data exposes some of the OpenSearch 1.1 Response elements in its search-results feeds.
The following table shows the elements of a Google Data Data:
Google Data services Google Data service returns a 304 (Not Modified) HTTP response.
A Google Data service Google Data Google Data:  Google Data services.
Optimistic concurrency (version Google Data Google Data Google Data's responses compatible with non-Google Data would make it harder to retrofit Google Data on top of many existing data stores. Data Google Data Google Data services,