GET'> PUT'> POST'> DELETE'> '> '> ]> An API extension extends one or more of the following components of the core API: Resources. An extension creates object classes. Attributes. An extended attribute creates an attribute on existing resources. Prefixed by the extension name. Actions. An extended action creates an operation on an existing resource. Generic API extensions are not plug-in-specific. For information about plug-in-specific extensions that ship with OpenStack Networking, see the extension documentation in the source code tree.