An extension that adds one or more actions to the vSphere Web Client must define an action set. You add each action set extension to a specific extension point in the vSphere Web Client user interface layer, named vise.actions.sets.Your extension definition must define an action set as well as the individual actions within that action set. An action set is a data object of type com.vmware.actionsfw.ActionSetSpec. The ActionSetSpec object contains an <actions> property, which is an array of action data objects. You specify each individual action in the set inside the <actions> property, using a separate data object for each.You associate each action set extension with a particular type of vSphere object. It is a best practice to use the vSphere Web Client extension filtering mechanism to ensure that the actions are only visible when the user selects the relevant type of vSphere object. See Filtering Extensions.Important If you omit the <metadata> element for extension filtering in your action set extension definition, your action is shown for all vSphere objects. It is strongly recommended that you use the <metadata> element in your action set extension definition to ensure your actions are displayed only for the correct type of vSphere or custom objects.