Shelly ThreadLink explained: what it is and how it works with Home Assistant
Shelly ThreadLink is opt-in Thread firmware for Gen4 devices: what it runs, what border router it needs, and how it reaches Home Assistant.
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ThreadLink is a firmware Shelly announced on September 3, 2026 that moves an eligible Gen4 device off Wi-Fi and onto Thread, while keeping Matter, Shelly’s own local API and Shelly Cloud on that one radio.
Short version: ThreadLink is standard Thread underneath, with Shelly’s extras riding on top as ordinary IP traffic. It needs a Thread border router, which a Home Assistant install with a Connect ZBT-2 or a Yellow can provide, and it reaches Home Assistant through Matter today, with a dedicated Shelly module promised. It had not shipped as of October 16, 2026, and Shelly hasn’t said which Gen4 models will get it. Don’t buy anything for it yet. If you already own Gen4 relays, it’s worth planning a border router around.
This is a research piece. I run Shelly’s Wi-Fi and Z-Wave relays and a Connect ZBT-2, but I haven’t run ThreadLink, because nobody can yet. For the announcement itself, see my news brief on Shelly at IFA 2026.
What ThreadLink is
Shelly’s Gen4 devices use a multi-protocol chip with an IEEE 802.15.4 radio beside Wi-Fi and Bluetooth. 802.15.4 is the radio layer Zigbee and Thread both use. ThreadLink turns that radio into a Thread connection and runs a full IP stack over it: IPv6 with 6LoWPAN, UDP, and TCP for larger transfers such as configuration, diagnostics and updates.
Three things then share the radio:
- Matter, so the device shows up in Apple Home, Google Home, Alexa, SmartThings and Home Assistant.
- The Shelly RPC API, so Shelly devices talk to each other directly across the mesh. Shelly says scenes, interlocks and automations run peer to peer and keep running if the internet or the whole Wi-Fi network is down.
- Shelly Cloud, reached through the border router’s NAT64 translation, with no Wi-Fi credentials stored on the device.
Is it a Shelly protocol or standard Thread?
The mesh is standard Thread. Shelly says traffic is encrypted at the link layer per the Thread specification, that any Thread border router works, and that no proprietary gateway, hub or bridge is needed at any point. What is Shelly’s own is the layer on top: its RPC API and cloud connection carried as plain IP across the mesh, where most Thread products carry Matter and nothing else.
Which Shelly devices get it
| Device | Status, October 16, 2026 |
|---|---|
| ”Eligible Shelly Gen4 devices” | Announced September 3. Shelly said “approximately 3 month”, which points at early December. No firm date |
| Any named Gen4 model | I couldn’t find anywhere that says which models are eligible |
| Gen3, Gen2 “Plus”, BLU and Wave devices | Not mentioned. Shelly’s release only covers Gen4 |
ThreadLink is free and opt-in, installed from the Shelly app or the device’s web interface. You choose per device whether it runs the standard Wi-Fi firmware or ThreadLink. Shelly’s Gen4 Zigbee mode works the same way: the Shelly 1 Gen4 knowledge-base page has you press the button five times to switch from the default Matter profile to Zigbee. One radio, one job at a time.
The only Gen4 device I own is a Shelly Flood Gen4, a battery leak sensor, and I couldn’t find anywhere that says it will be eligible. The catalog has pages for the Shelly 1 Gen4, 2PM Gen4, Dimmer Gen4 and Plug US Gen4, and none of them is confirmed for ThreadLink either.
What hub or border router it needs
No Shelly hub. ThreadLink needs a Thread border router on the home network for app control and cloud access. Shelly names a Home Assistant-based router or the routers in Apple, Google and Amazon hardware. Device-to-device scenes run inside the mesh and don’t need one.
Home Assistant’s Thread docs list the Yellow, Connect ZBT-1 and Connect ZBT-2 as border routers once the OpenThread Border Router app is installed, plus Apple’s HomePod mini and HomePod (2nd gen) and Google’s Nest Hub (2nd gen) and Nest Hub Max. The Yellow and the ZBT-1 are both discontinued - existing ones still work, and the ZBT-1 still gets software updates - so the ZBT-2 is the one to buy new. Home Assistant can use any border router, but can only configure OpenThread ones. My Thread border router guide goes through the choice.
How it shows up in Home Assistant
| Path | Status | Local? |
|---|---|---|
| Matter integration | Shelly says ThreadLink devices are exposed over Matter | Yes. Home Assistant’s Matter docs say Matter devices are always locally controllable, with no internet or cloud needed |
| Shelly integration | Shelly promises “a dedicated module” with the full Shelly feature set beyond the Matter data model | Unknown until it exists |
Home Assistant’s Shelly integration today is local push and supports all four Shelly generations, but its docs don’t mention Thread or ThreadLink. I couldn’t find anywhere that says whether Shelly’s module will be a change to that integration or a separate component. Until it appears, plan on Matter, which needs the Matter Server app alongside the border router. Matter is multi-fabric, so the same relay can sit in Apple Home and Home Assistant at once.
ThreadLink versus Shelly’s other radios
| Line | Radio | Needs | Home Assistant path |
|---|---|---|---|
| Wi-Fi Gen3 and Gen4 | Wi-Fi and Bluetooth; Gen4 ships with Matter as its default profile | Your Wi-Fi | Shelly integration, local push; or Matter |
| Gen4 Zigbee mode | Zigbee 3.0, repeater | A Zigbee coordinator | Zigbee |
| Gen4 ThreadLink (not shipped) | Thread | A Thread border router | Matter now; Shelly module promised |
| Shelly Wave | Z-Wave, Long Range on some variants | A Z-Wave controller | Z-Wave |
My own house sits closest to the first and last rows: Wi-Fi Shelly relays from the older Gen2 “Plus” line, such as the Shelly Plus 1, which Shelly has discontinued in favor of the 1 Gen4, and Z-Wave ones, the Shelly Wave 1PM and Wave 1PM Mini, and they’re some of the most reliable devices I run. That is the comparison ThreadLink has to win.
Who should care
- Gen4 owners with a border router already. You get a free way to take relays off Wi-Fi without losing Shelly’s API. Wait for the eligible-model list.
- Anyone fighting a crowded Wi-Fi network. A Thread relay is one less Wi-Fi client, and Shelly’s device-to-device scenes keep working through a router outage.
- Apple Home and Google Home users. A HomePod mini or a Nest Hub (2nd gen) is already a border router, and Shelly says ThreadLink devices appear natively in both ecosystems.
- Zigbee and Z-Wave houses. Little changes. Your mesh already works without Wi-Fi, and Shelly’s Zigbee and Wave lines stay where they are.
I’ll update this page when Shelly publishes the eligible models and the firmware ships.