Home Assistant's stable Matter Server app moved to version 9.1.0 on July 15, 2026. It bundles Open Home Foundation Matter Server 1.2.6, bringing Matter 1.6.0 support to Home Assistant's controller stack along with automatic device time synchronization and experimental management for intermittently connected devices. That closes one platform-version gap, but it does not switch on every Matter 1.6 feature across the devices in a home.
For an existing Home Assistant household, this is a controller update rather than firmware for a lock, sensor, thermostat, or bridge. Home Assistant runs the Matter Server app as the controller process behind its Matter integration. Its documentation identifies Home Assistant OS with the official app as the supported route and calls a standalone Matter Server container unsupported. Updating the app can improve what the controller understands, but it does not update connected accessories or remove their manufacturer-specific limits. There is no reason to reset or recommission a working device just because the server now speaks a newer Matter version.
The change is a concrete follow-up to Matter's platform timing problem. Home Assistant's June Matter Server 9.0 release was based on Matter 1.5.1 and said 1.6 support was still coming. Version 9.1.0 supplies that controller foundation less than a month later.
Time sync and sleepy devices still need cooperation
Time synchronization is the clearest immediate addition. The new time_sync setting defaults to auto, which enables it only when the Home Assistant host clock is synchronized through NTP. Matter Server then pushes UTC time, time-zone, and daylight-saving information to devices that support the relevant Matter feature. The server schedules its first update within 30 to 60 minutes of startup and repeats it every 24 hours. A device that does not support time synchronization will not gain it from the controller update.
The intermittently connected device work is more experimental. These are devices designed to sleep between check-ins, a pattern common in battery-powered Matter accessories. Matter Server adds management for short- and long-idle-time modes and a Power & Sleep panel in its dashboard. Long-idle-time management requires support from a Matter 1.4 or newer device. This is not a promise that every existing sensor will last longer on a charge, and Matterhome has not tested the new controls.
Version 9.1.0 also lets an advanced user pin the Matter fabric label instead of allowing multiple Home Assistant connections to keep changing it. That is useful mainly in installations where more than one Home Assistant instance talks to the same Matter Server. Most single-instance homes can leave the default alone.
Matter 1.6 defines broader changes such as Joint Fabric, expanded NFC commissioning, and thermostat coordination. Controller-side protocol support is necessary for that work, but Home Assistant's 9.1.0 notes do not claim that each of those experiences is ready in the Home Assistant interface or on current devices. The accessory, its firmware, the controller integration, and the user interface still have to support the same path.
Owners already running Matter Server 9.x can treat 9.1.0 as a point update. Anyone jumping from 8.x should also read the 9.0 migration notes, make a full backup, check free memory, and allow extra time for the first start while the server data migrates. After updating, confirm that the Matter Server app starts normally and test one noncritical device before relying on locks, heating, or other important automations. Use the stable app update rather than enabling the Beta option only to chase a version number.
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