Adding custom properties from external source to existing vSphere Managed Entities

Hi,

I would like to display additional properties to existing vSphere managed entities (e.g. Hostsystem) in the H5/webclient. The additional properties are coming from another source (through an API).

From reading the documentation, I know that in the service layer I need to create a Data Service adapter. However, this comes in two forms:

1) Property Provider Adapter (PPA)

2) Data Provider Adapter (DPA)

I would like to know which of these (or both) I need to create?

I was thinking that I need to create a PPA because the documentation says this:

"Property Provider Adapters

You create a Property Provider Adapter to allow the Data Service to access new properties for existing 

vSphere objects, such as virtual machines or hosts. For example, your vSphere environment might contain 

custom virtual machines or hosts that provide extra properties not normally available through the Data

Service. You can create a Property Provider Adapter to extend the Data Service to fetch these additional

properties."

However, it also looks like a PPA can only be used to collect properties from vCenter?

Could you please advise what is the correct approach to being able to achieve this please? 

Many thanks.