The Aqara Smart Lock U400 is a fingerprint deadbolt with native Matter over Thread and UWB Apple home key, so an iPhone or Apple Watch unlocks the door hands-free. Home Assistant controls it locally through the Matter integration.
Replaces the whole deadbolt, with the fingerprint reader and keypad on the outside. UWB lets an iPhone or Apple Watch with Apple home key unlock the door as you walk up, with no tap.
Needs a Thread border router and a Matter controller, after which control is local. Fingerprint and PIN management stays in the Aqara app or Apple Home. Comes in black and silver.
Entities in Home Assistant
Typical 9 entities via Matter
This model has no device dump in Home Assistant's test suite, so the list below is what a Matter Door Lock exposes at minimum. Optional features the manufacturer implements add entities on top.
Primary entities 1 What automations and dashboards use.
| Entity | Type | Device class | Unit |
|---|---|---|---|
| Lock (main) | lock | — | — |
Configuration 6 Settings exposed as entities, tunable from Home Assistant.
| Entity | Type | Device class | Unit |
|---|---|---|---|
| Auto-relock time | number | — | s |
| User code temporary disable time | number | — | s |
| Wrong code limit | number | — | — |
| Operating mode | select | — | — |
| Sound volume | select | — | — |
| Privacy mode button | switch | — | — |
Diagnostics 2 Health and troubleshooting values, hidden from dashboards by default.
| Entity | Type | Device class | Unit |
|---|---|---|---|
| Actuator | binary_sensor | — | — |
| Battery | binary_sensor | battery | — |
Derived from Home Assistant 2026.8.3: the entities every reference implementation of a Matter Door Lock produced in core's own tests. A floor, not the full list for this model.
Where to buy
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Recipes using this device
Auto Lock at Night
Installs a Home Assistant automation that locks your smart locks at a set time every night. Add door sensors and it holds off while a door is still open, then locks the moment the last one is shut.
Unlock on Arrival
Installs a Home Assistant automation that unlocks the door when you get home, and only when the house was locked, so you are not fishing for keys with an armful of shopping. Add lights and it welcomes you into a lit hallway after dark.