vCO 5.5.1 api action execution

I see on the info listed at VMware released vCenter Orchestrator 5.5.1 there is a note about being able to execute actions from the vCO api.

There are a few REST API new calls in 5.5.1

One noticeable new features is that you can start a vCO action through the REST API:

• POST /actions/{actionId}/executions Runs an action with given ID
• POST /actions/{categoryName}/{actionName}/executions Runs an action with given category and name

In my actual install of 5.5.1 however I don't seem to be able to find this API feature at all. Are the notes here wrong or am I looking in the wrong place?