Sorry for the delay, but here's a couple of answers, first:
Cobra is auto-generated for the most part and isn’t getting tons of attention from a roadmap/features standpoint. For what it’s worth, event subscription is a very simple thing with the ACI toolkit. Nothing prevents you from using both Cobra and the ACI toolkit modules inside your code.
In addition to raw URL subscriptions, you can also subscribe to ACI toolkit objects, such as this example:
I am in the same situation as Garland (2 years later).
I know that it can be done witch ACI-toolkit, but that implies having to deal with 2 external modules.
I've also found in https://github.com/datacenter/cobra that the branch eventchannel was created 3 years ago, however it is still not included in the lastest versions of Cobra, and there is no documentation available to use this branch.
Also, I tried to contact via email to the cobra support team at firstname.lastname@example.org to ask, but it seems that this email address is no longer available.
Having passed 2 years since the initial request, could you please tell me when event subscription is going to be available natively in Cobra?
Thank you very much.