Google's mystery HDMI dongle is actually the ADT-2 Android TV developer kit

That mystery Google-branded HDMI dongle we saw pass through the FCC about a month ago looks to be not a consumer device, but instead developer-only hardware called the ADT-2 that Google's announcing at I/O 2018. So no, that wasn't an early look at any sort of consumer-level hardware as originally expected, but it is something that will help developers get acquainted with developing for Android TV.

What's new in Android TV at Google I/O 2018

As expected given its development focus, the ADT-2 is a pretty simple device. Google isn't even disclosing the specific hardware specs inside — but we do know that it's roughly the size of a Chromecast Ultra, with an HDMI plug on one end and a power port on the side. And despite its small size, it runs Android TV — in fact, it'll run Android P when it finally ships out to developers. It will also have a remote, which is built on a new reference design for hardware manufacturers that want to make Android TV hardware.

This is purely for developers, but it can provide a couple clues for the future.

The goal of the ADT-2 kit is to have an easily-accessible device that developers can move from display to display while they're working on applications, especially because the Nexus Player is no longer supported as a reference device. Sure this isn't a new device that we can go out and buy (at any point, let alone right away), but it does indicate that Google is actively working on Android TV and working to entice developers to work with the platform. And it shows that Google is designing Android TV to run on such a small device, with a remote — those could be clues to potential future devices.

Google says the ADT-2 reference device will ship out "later this summer" (remember, Android P has to be closer to finished) and interested developers can sign up to receive one once it becomes available. The rest of us can wait and see what comes from a bunch of these developments kits being out in the wild.