A:Answer Actually -- this is a bit confusing (probably why 2 different people gave different answers).
The deal is: If you have an AppleTV 4th. generation or later, HomeKit uses it automatically as its "hub" out to the Internet. (You can also designate an iPad as the hub for this purpose, but obviously - it has to be left at home on your wi-fi network for that to work. So the AppleTV just makes more sense as one in most cases.)
With that "hub" in place, HomeKit has a way to talk to August devices that have been added to it. You have to remember though -- the August locks and keypads run on low power Bluetooth. So their range isn't more than 10-12 feet or so from the device talking to them. That's great if you're using the August app on a smartphone that's near the lock as you walk up to the door. But not so great for these hubs to communicate with them. If your doors are only 10 feet or so away from your AppleTV, you're good. Otherwise -- you might have issues.
In my own case? My back kitchen door is working pretty good with an August lock and HomeKit. But that's because I have an AppleTV in the family room that's right off of the kitchen. My side door on my detached garage also has an August lock and HomeKit just gets errors trying to lock or unlock it. The Bluetooth commands just can't reach it from the AppleTV in the house. So I'm going to try buying the August Connect device and placing it out in my garage, attached to my wireless satellite router that's already in the garage. That *should* get it going.
