The contract version denotes the data model and behavior that the API
supports. This API documentation provides information about Identity
v2. The requested contract
version is included in all request URLs. Different API contract versions
might be available at any given time and are not guaranteed to be
compatible with one another.
The URI scheme for API contracts supports the following development practices:
New features and functionality that do not break API compatibility are introduced in the current version of the API as extensions. The URI version stays the same. For example, the Identity service is developing the RAX-AUTH extension to develop new services and resources to support the Rackspace implementation of OpenStack Keystone v2.0.
Service providers must change the API contract version anytime they introduce or deprecate features or functionality that make the API incompatible with previously released versions. When the version changes, the target version in the URI is updated, from v2.0 to v3.0 for example.
When new API versions are released, older versions are
DEPRECATED. Because a service endpoint can host multiple API versions, service providers can work with developers and partners to ensure adequate time to migrate to the new version before removing the deprecated version from service.
You can use the Version API operations to get more detailed information about the Identity API contract version.