First attempts with Matter over Thread, at a loss

[oliof (Harald)]

So, for the longest time I was avoiding Matter because I already have BLE, Zigbee, ZWave. But the cheap IKEA Smart Home products made me reconsider.

For testing, I ordered an IKEA Grilplats Smart Plug, and an IKEA Timmerflotte Temperature/Humidity sensor.

I have a ZBT-1 with the thread firmware, and it shows up as an OTBR in Home Assistant:

For some reason that I dont fully grok, there are two thread networks, and I have no ability to delete the one that's not preferred.

Now, when the devices turn on, my Android phone wants to set them up, but I don't know if this is Google Home or Home Assistant, so I back out of that.

Then I go to the Companion app, Settings > Matter > Add device

I scan the QR code and I get a wait screen that the device is being set up, which then goes to "Your device requires a Thread border router. Connect your border router, then try setting up your device" and the onboarding of the device fails.

I looked at the documentation about setting up the ZBT-1 as an OTB and followed it to my best ability. I looked at the documentation about Thread networks and validated no other Thread networks governed by Apple or Google exist. I also read Thread - Home Assistant.

This is on HAOS 18.1, and Home Assistant 2026.7.

Is there something I missed? How can I make sure there is only a single Thread network? How do I convince the Matter component of Home Assistant that the OTBR based on the ZBT-1 plugged into the machine running HAOS and shows up as an OTBR can be used for Matter devices?

If all else fails, how can I completely reset the whole thing so those Thread networks go away, and I can start from a clean slate again?

[oliof (Harald)]

After

• deleting the Matter Integration
• reflashing the ZBT-1 via the toolbox
• setting up everything from scratch

I was able to get one thread network with an assigned border router (checked via both Settings > Integrations > OTBR, and Settings > Integrations > Matter > Thread settings).

Still, commissioning the device fails with the error that I need a Thread border router.

Can anyone confirm that a Home Assistant/ZBT-1/Companion app based Matter over Thread setup actually works?

[agners]

The setup works, and is proven in countless installations.

@oliof

Still, commissioning the device fails with the error that I need a Thread border router.

Are you using Android?

Make sure to follow the steps outlined in Case 1: Making Home Assistant your first Thread network exactly. Be careful to define the correct network as preferred network before doing the sync, and don't delete that network afterwards! Android does NOT allow you to delete the Thread credentials (there are work arounds by deleting Google Play Store storage, but it has side effect like lost wallet etc.!)

[oliof (Harald)]

Yes, I am using Android, but how is Google Play involved? I am only using the function within the Companion app.

After I completely re-flashed the ZBT-1 and re-set up everything, a new network appeared in the Thread list, with an associated key, and with the "key in mobile" icon.

But still, the comissioning flow ends up in telling me I need to add a border router.

The "Send credentials to home assistant" button tells me "You don't have any credentials to import". That sounds like, no I dont have anything on my phone related to thread or a network?

So, am I right to understand despite never having any Google or Apple device as a border router, because the Companion app runs on Android, since I had the gall of trying to reset the setup for a clean slate, I cannot do so without breaking my Android device to some extent by deleting the Play Store cache?

[agners]

@oliof

Yes, I am using Android, but how is Google Play involved? I am only using the function within the Companion app.

The Companion app calls Play Store API's to commission Matter devices. It uses the Matter framework shipped with the Google Play Store services, and Google got certified with the CSA.

@oliof

The "Send credentials to home assistant" button tells me "You don't have any credentials to import". That sounds like, no I dont have anything on my phone related to thread or a network?

This does things the other way around: If another ecosystem (e.g. IKEA) added Thread network, it sends that network information to Home Assistant. That is not what you need.

Please read the docs carefully. Since the sync can't be undone, we hide it a bit I am working on improving the UX of this a bit, I know it is bad .

@oliof

So, am I right to understand despite never having any Google or Apple device as a border router, because the Companion app runs on Android, since I had the gall of trying to reset the setup for a clean slate, I cannot do so without breaking my Android device to some extent by deleting the Play Store cache?

Yes, once you have a Thread credentials defined as "preferred" on Android side it "sticks" there. But from your description, it doesn't seem you have synced the credentials yet. Just saying this as a heads up: Once you synced the first time, this will the preferred Thread your network on that phone/Google account.

[oliof (Harald)]

I can depend on Google do mess up things badly, it seems. Not much has changed since my time there, where "give up and use multiple devices" often was the solution for problems people living in and never leaving California couldn't begin to fathom (like spending equal time in two different countries for example).

I did pull out my iPhone (for business reasons I need to have both), and with that, I was able to commission the device just so.

[boheme61 (JC)]

@agners

The Companion app calls Play Store API's to commission Matter devices. It uses the Matter framework shipped with the Google Play Store services, and Google got certified with the CSA.

Are You saying that Our Companion app, "pump" Google with info about our devices in HA ?
( And which CSA are you referring to ? )

[oliof (Harald)]

And a follow-up question @agners: People using things like GrapheneOS, can they actually comission Matter over Thread devices?

[agners]

@boheme61

@agners

The Companion app calls Play Store API's to commission Matter devices. It uses the Matter framework shipped with the Google Play Store services, and Google got certified with the CSA.

Are You saying that Our Companion app, "pump" Google with info about our devices in HA ?
( And which CSA are you referring to ? )

If you commission a Matter device via Home Assistant companion apps, we use Apple and Google API do make this happen. What these framework exactly do I can't say for sure, but commissioning happens local.

CSA as in Connectivity Standards Alliance, the body who governs the Matter standard.

[agners]

@oliof

And a follow-up question @agners: People using things like GrapheneOS, can they actually comission Matter over Thread devices?

Unfortunately yes. We could make this happen, but we'd have to build the native part of the Matter framework and ship it with the app. Nobody cared to dive into it yet .

You can use a local Bluetooth device on your Matter Server and do direct commissioning, or via Bluetooth Proxy.

[oliof (Harald)]

@agners

ou can use a local Bluetooth device on your Matter Server and do direct commissioning, or via Bluetooth Proxy.

Is this possible with HAOS? I'd be interested to learn more. I have about a dozen Bluetooth proxies in the house.

[oliof (Harald)]

To answer myself: Yes. Locate Matter Server in Apps, open web UI, store Thread credentials, commission, enter commissioning key of device, wait a minute, and it's available.

Needs a bit of work afterwards renaming the device and assigning an area, but I'm mostly happy with that.