is Zwift getting the actual power reading from my computrainer?

Yes but their api seems to include a WFConnector library which doesn’t include the source. 

They seem to share it in the same way as Racermate.  I had to go to their website and fill out a form with email and agree to their terms.

I’m just trying to see how the 2 api’s differ in terms of what is included.

So far, they are seeming fundamentally the same to me.  An interface allowing the interaction with a non source provided underlying library.

You have the Racermate library?

I’m guessing not… 

I do.   What are getting at?

Both APIs are fundamentally the same inasmuch as they are both libraries with an interface and you do not get the underlying code.

If you scroll back a bit, someone from Zwift claimed that the reason they won’t use the Racermate API is because “they compile everything they use from code and aren’t keen on using a prepackaged library”.

The Wahoo library is just that.