I’ve been diving deep into Matter signals from my Aqara setup to Home Assistant over the past few days. In each bedroom, I use an Aqara Air Quality Sensor (imported from China) to monitor CO2 levels — because sleep quality matters, especially when CO2 gets over 1000 ppm.
To keep things fresh (literally), I have decentralized fans from SIKU installed that kick in when CO2 rises. All good so far. BUT… I just hit a very unexpected wall.
It seems the number of Matter signals that can be sent through my M3 hub is extremely limited — we’re talking less than 20 signals (!). Is that really the case? That would be way too low for any serious setup.
Even though I’ve integrated my Aqara hubs into Home Assistant, I still can’t see all devices there. And when I want to use these devices in more complex automations — especially involving non-Aqara devices — I’m stuck.
Anyone else run into this? Any ideas, workarounds, or magic spells to break the limit?
Always remember: “If your car is smarter than your home… you’re driving into the future while living in the past”
@RudyK Thanks for sharing your detailed experience and raising this excellent question about Matter integration limits with your M3 hub!
From the available official reference, Aqara hubs with Advanced Bridge functionality (including M3) indeed support bridging to third-party Matter ecosystems like Home Assistant, Apple Home, Google Home, etc. (See official info). However, the documentation doesn’t explicitly specify a hard cap on the number of Matter signals or devices that can be exposed at once—nor does it confirm the <20 limit you mentioned.
What is confirmed is that:
You can expose Aqara devices to third-party Matter ecosystems via the hub’s Advanced Bridge feature.
Some device and scene types, or private functions, may not be fully bridged or visible in third-party platforms. This means not all Aqara devices or their features will necessarily appear in Home Assistant even if they work in the Aqara app.
There may be technical or firmware-based limitations on how many devices or endpoints the hub can bridge at a time, but this number isn’t officially documented in the references I have.
So, while your observation of a “less than 20” signal/device limit feels plausible (especially with imported devices or complex automations), it’s not officially stated—so please take this as a reference point rather than a confirmed restriction.
Ideas & Workarounds:
Double-check your hub’s firmware and Home Assistant’s Matter integration are up to date; sometimes, updates expand compatibility and limits.
In the Aqara Home app, review which devices are exposed to Matter. Try toggling which devices/scenes are bridged to see if you can swap or rotate the set.
Some advanced users run multiple hubs if they hit device limits, distributing devices between them for broader coverage.
For truly complex automations, sometimes keeping part of the logic in the Aqara app and part in Home Assistant, with minimal Matter bridging, can help bypass some platform limits.
Community Call:
If anyone has encountered and conquered this “20 signal” ceiling—especially with imported sensors—please jump in! Have you found firmware tricks, alternative bridge setups, or other integrations that let you scale beyond this?
And thanks for the fun quote—smart homes should definitely keep up with our cars!
Let’s keep exploring together—your insights help drive the smart home community forward!
Due to the recent release of the Advanced Matter Bridging feature, it is currently in a “limited trial” phase, and therefore we have imposed a quantity restriction. Sorry for any inconvenience caused. We will also reconsider the quantity restrictions.
Actually, the main purpose of this “signal” is to bridge private features not supported by Matter to Home Assistant as automation triggers. Devices supported by Matter can be directly bridged to Home Assistant to create automations.
Thanks for the explanation! I’m actually using the signals exactly for that purpose: connecting Aqara with devices that cannot be integrated into Aqara directly and that don’t support Matter.
In my case, these are decentralized ventilation units in different rooms that ensure fresh air. Simply switching them on or off with a relay is not enough – they can push air out, pull fresh air in, or run in an oscillating mode (using a ceramic heat storage core to save energy in winter). On top of that, their performance can be adjusted from 0–100%. And in Home Assistant, I also combine this with other information such as indoor and outdoor temperature to make the automation smarter.
My plan was to use the Aqara S1 Air Quality Sensors to steer them, since the sensors provide signals like “CO2 level becomes excellent / light pollution / severe pollution.” With five sensors, that’s already 15 signals going to Home Assistant. Add a few more signals, and you hit the limit very quickly.
That’s why I would really appreciate it if Aqara could lift this restriction – otherwise, it’s almost impossible to use the signals in a meaningful way.
@Peng Any update on lifting the restriction? I could really use some more signals. I have so many devices from Aqara not visible in Home Assistant, but I need the triggers or I need to trigger the devices. Any plans to get rid of this 20 signals limitation? I would highly appreciate it! Thanks for considering…
Due to the limitation, I would suggest taking a different approach. Home Assistant offers many possibilities.
So instead of:
Aqara → Signal → Matter → HA
You could also take the following route:
HA → Toogle(on/off) → Matter → Aqara
Create several Helper Toogles in HA and pass them through to an Aqara hub (Matter controller) using a Matter Bridge (add-on). After that you can switch the switches on and off using automations in the Aqara app. Each state of the Aqara Air Quality Sensor can then be a Toogle in HA.
Aren’t the Aqara Air Quality Sensors HomeKit compatible? Then you should be able to integrate them into HA using the HomeKit Device Integration.
Hi @JohnD — thanks for the feedback. Sounds promising, for sure. I did a bit of digging, and unfortunately I couldn’t find any Matter-Bridge add-on for Home Assistant. It also doesn’t seem possible - for the time being - to expose devices from Home Assistant as Matter devices so they can be passed along to other bridges (like Aqara). Do you happen to have more information on this, or a link to some documentation?
