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Somfy io shutters in Home Assistant — fully local, for €80

If you own Somfy shutters, you'll quickly discover there are two very different worlds behind the brand: RTS and io-homecontrol. RTS is the old, unencrypted protocol — you can control it with a cheap RF transmitter like an RFXtrx or an ESP32 running ESPSomfy. io is a different story entirely, and every road to an io device runs through an official Somfy gateway.

The good news: one of those gateways is the cheap one, and it can be made completely cloud-free. This is the setup I run, and it works.

Why you can't just build your own io receiver​

io-homecontrol was developed by Somfy and Velux as a closed consortium protocol. The radio traffic on 868–870 MHz is AES-128 encrypted, and the keys are exchanged individually between transmitter and motor during pairing. Even if you capture the packets, you can't read or replay them without the key. On top of that, the chips and the protocol spec are only available under NDA to licensed partners.

There have been reverse-engineering attempts in the community, but device-specific key management makes a complete open implementation impractical. So the art isn't in avoiding the gateway — it's in making the gateway as local as possible.

(A small consolation: the encryption is also a genuine security feature. With RTS, anyone with a €20 radio module can theoretically raise your shutters. With io, they can't.)

The setup: Connectivity Kit + HomeKit​

The Somfy Connectivity Kit is the cheap gateway, around €80. It's a perfectly good local option — just not the way most people expect.

Developer Mode does not work on the Connectivity Kit. Somfy deactivated it and says it was never meant to be supported there; officially it's only for the TaHoma Switch, Premium and DIN-Rail. So the local Overkiz API, which is what most guides point you at, is off the table.

But the kit speaks HomeKit, and Home Assistant's HomeKit Device integration is 100% local. That's the cloud-free path.

1. Initial pairing (needs internet once)​

Set the kit up with the "TaHoma by Somfy" app and pair your io shutters to it. There's no way around the Somfy account for this one step. Note that the kit is 2.4 GHz Wi-Fi only.

2. Get the HomeKit setup code​

It's on the sticker on the device, in XXX-XX-XXX format. If it's missing or unreadable, add the Overkiz integration via the Cloud API temporarily — a HomeKit Setup Code sensor will appear in Home Assistant. Note the code, then delete the Overkiz integration again.

3. Pair with Home Assistant​

HA and the kit must be on the same network/VLAN so mDNS discovery works. The kit should show up automatically under Settings → Devices & Services as a HomeKit accessory. Click Configure and enter the setup code.

Important: it can only be paired to one HomeKit controller. If it's already in Apple Home, remove it there first.

4. Done​

Your io shutters appear as cover entities with position control, fully local.

Cutting the internet​

Once paired, you can block the kit's internet access entirely — HomeKit control is purely local, so the shutters keep working.

Don't disconnect it from Wi-Fi; it still needs the LAN to talk to HA. Instead block only its WAN access in your router, identifying it by the MAC address printed on the back. Give it a DHCP reservation first — a fixed IP keeps the HomeKit connection to Home Assistant stable long-term.

What you lose while it's blocked:

  • TaHoma app control — that goes through Somfy's cloud
  • Adding/removing shutters or changing kit settings — re-enable internet temporarily when you need this
  • Firmware updates — worth unblocking briefly every few months
  • Alexa / Google Assistant — both are cloud services. You still get voice control through HA Assist, or through Siri if you pair the kit with Apple Home instead.

Scenes created in the Somfy app aren't exposed via HomeKit either — but you'd build those in Home Assistant anyway, which is far more flexible than Somfy's own.

Is this a safe bet long-term?​

The kit is still sold and actively maintained — TaHoma app updates (2.6 in January 2026) explicitly cover it, and it still gets new features like widgets. No end-of-life announcement.

The honest caveat: Somfy has already switched off two interfaces on this device — first the old Somfy Open API, then Developer Mode in late 2025. The company clearly will remove functionality via firmware update when it considers an integration path unofficial.

What makes the HomeKit route different is that HomeKit is an officially advertised, certified feature ("Works with Apple Home" is on the box). Somfy can't quietly kill that without upsetting paying Apple customers and risking certification trouble. That's why the HA community treats it as the most stable path for this device — considerably safer than Developer Mode ever was.

And there's a nice side effect of going local: once the kit is paired with HA over HomeKit and cut off from the internet, Somfy can't change anything about it anymore. It's effectively frozen, and it keeps working as long as the hardware lasts.

Addendum: the other options, for reference​

TaHoma Switch + local Overkiz API​

The community's "proper" solution, ~€150–180. The Switch officially supports Somfy's Developer Mode, which unlocks the local Overkiz API — position feedback, fast polling (5 s), more sensors, and no cloud during normal operation. Only the one-time activation of Developer Mode requires internet and a Somfy account.

Setup: pair devices via the TaHoma app → enable Developer Mode for your account on the Somfy website → in HA, Settings → Devices & Services → Add Integration → Overkiz (often auto-discovered) → choose Local API and generate a token during the flow.

Two tips from the docs: if entities keep going unavailable, connect by IP address rather than the gateway-xxxx.local hostname. And on io venetian blinds, don't send position and tilt as separate commands — that causes stuttering; use the combined Set cover position and tilt action.

Worth the upgrade if you want sensors and position feedback, or if you're past the Connectivity Kit's 20-device limit.

Overkiz Cloud API​

Works with any gateway including the Connectivity Kit, but runs through Somfy's servers — so it defeats the purpose if local control is the goal. Two things to know if you use it anyway: the API is rate-limited, so avoid automations that fire rapid bursts of commands; and some devices don't broadcast state changes on their own, so opening the Somfy app is what triggers a status refresh the integration then picks up.

Velux KLF-200​

An io-homecontrol gateway with a local API, to which Somfy io motors can also be paired. HA has a native Velux integration. The catch: it's discontinued, and used units often cost more than a TaHoma Switch. Only interesting if you find one cheap.

If you actually have RTS motors​

Skip all of the above. RTS is unencrypted and well supported by DIY hardware — an RFXtrx or ESPSomfy on an ESP32 will do the job for a fraction of the price.