So confused by thread setup on HA Yellow

I’m new to thread, but thought I was smart to purchase new smart blinds with Matter support.

I have the following:
-HA Yellow
-Nest Hubs

I have Zigbee working fine (ZHA) with several devices (lights, temp sensors).

I spent hours trying to understand how to get a thread border router working and if I need new hardware or note. In HA Yellow documentation they say to disable Zigbee which I don’t want to do, because I have Zigbee devices (which are also hard to access so I don’t want to go re-pair them)… It seems I might be able to get multi-protocol support working but I can’t find any clear instructions on how to do it. If I try and add OTBR integration it asks me for a Rest API Url, which I don’t have - I don’t understrand how to get this from Nest, and don’t see why I need it if I can use the HA Yellow radios…

So, I’m very confused! What’s a simple, cheap way to get OTBR working on my HA Yellow? Should I buy a Sky connect or Sonoff ZBDongle-E and set it up with thread only firmware? Or can I make what I have work?

thank you!

Thread is a wireless IP networking standard, analogous to WiFi. The main differences are that it is low-power, to better suit battery-powered devices, and with built-in mesh capability, so non-battery devices can extend the range. By itself, it has no “smart home” features — like WiFi, it just connects things.

Since a Thread IP network is a different subnet (address range / broadcast domain) than your WiFi network, you need a router to interconnect them — just like you need a router to connect your LAN subnet to the Internet. A router simply routes packets between subnets. Thread calls them “border routers,” to differentiate from the signal repeaters.

For several years now many WiFi routers have been incorporating Thread Border Router functionality into the same device — such as Eero (max) and Nest hub/wifi routers. You should check your Nest Hub’s capabilities — if it’s a 2nd gen or later it already has a built-in Thread Border Router and you don’t need to add anything, you should be ready to go.

Other devices such as some Apple TVs, HomePods, and Amazon Echos now have Thread Border Routers, so there is a decent chance you already have one. If you do not already have a Thread Border Router you will need to add one to your network — either by upgrading your router, purchasing an aforementioned multi-function device, or by making one yourself using free OTBR software. You can use a SkyConnect for this, but not if it’s already being used for Zigbee. You can even use ESP32 modules for around $10. Generally you only need to enter the REST API URL in HA if you are rolling your own OTBR (and maybe for Eeros).

Once you have a Thread Border Router, the trickiest part is deploying (“provisioning”) Thread devices — in other words, getting devices online with the right security credentials (“dataset”). If the device supports Matter, the HA docs have a decent summary of the process, but be aware that with a Google Nest Thread network you will need the HA Companion Android app.