FYI, Nabu Casa’s Zack Barett has announced on Twitter that Home Assistant founders are working on an official Home Assistant SkyConnect USB Stick (ie. a physical radio adapter/dongle hardware).
Nabu Casa electronics engineer developer (and Home Assistant developer) agners is designing the hardware for this USB RF-radio hardware for direct-attachment via USB will be based on a Silicon Labs EFR32MG21 SoC and that is an IEEE 802.15.4 multi-protocol 2.4GHz radio MCU that is capable of concurrently running both Zigbee 3.0 (EmberZNet/EZSP) and Thread (OpenThread/Spinel inc. Matter/CHIP over Thread) stacks/protocols at the same time by using firmware in RCP RCP (Radio Co-Processor) mode. Direct local serial communication will be done via an onboard USB-to-UART bridge/converter (presumably a chip in Silicon Labs CP210x series).
Be sure to fill out Home Assistant SkyConnect interest form so they know how many they should make:
Again, this USB dongle hardware is based on the EFR32MG21 SoC same chip used in Home Assistant Yellow (formerly Home Assistant Amber), although rather than a board built from scratch like this Home Assistant SkyConnect USB Stick the adapter inside the Home Assistant Yellow uses an Silabs MGM210P radio board (which in turn is a pre-certified RF module that contains the combination of an EFR32MG21 SoC and an onboard Ceramic Chip Antenna as its core components + will use a different firmware as GPIO pinout are not the same as the Home Assistant SkyConnect USB Stick dongle/adapter).
Home Assistant / Nabu Casa developer agners are also working on several add-ons that will also allow both these adapers to concurrently as Zigbee Coordinator and as an OpenThread Border Router (OTBR) for Thread-based Matter/CHIP-compatible devices (communicating locally over a USB-to-serial port using OpenThread RPC Spinel interface over UART. Silabs EmberZNet EZSP interfaces for Zigbee via the zigpy libraries will also enable support to the ZHA (Zigbee Home Automation) integration out-of-the-box.
There are also some discussions about Zigbee and Thread radio hardware adapter compatibility here:
PS: EFR32MG21 is by the way the same Silabs radio MCU chip used in ITead Zigbee 3.0 USB Dongle Model: 9888010100045 (Hardware Revision Version 1.3), more information about that adapter here: