Harmony firmware officially supports XMPP again - sort of.

[jonhanford]

I guess the only issue is with the readme, to be fair. :-)

Anyway, better late than never they've added XMPP support back to the main firmware starting with 4.15.250. It's officially supported again, though officially, it's unsupported. (adorable)

Nota Bene: XMPP must be explicitly enabled in the harmony app

Detail:
Logitech Forums: Update to Accessing Harmony Hub's Local API via XMPP

side note: cute that they say one voids their warranty by turning on that access. That legally does not void the warranty, as per the Magnuson-Moss Warranty Act of 1975, but I would surmise their disclaimer is more about explicitly making this feature unsupported than it is actually an attempt to void warranties.

Anywho, the API lives on. (until the next time they decide to brick an ecosystem at least)