Problem statement
Matter 1.6 was released by the CSA on June 17, 2026. It is a focused feature release that refines device setup, multi-ecosystem coordination, and how devices communicate their capabilities and operational state. Key additions relevant to Home Assistant as a controller include NFC-Based Commissioning, Joint Fabric for multi-ecosystem device sharing, and standardized device capability communication. The HA Matter Server (matter.js) currently targets Matter 1.5.1, with 1.6 support confirmed as the next step.
Adopting Matter 1.6 is also the right moment to close a more fundamental gap in HA's controller implementation: proper support for ICDs (Intermittently Connected Devices). ICDs are the dominant form factor for battery-powered Matter devices, covering sensors, buttons, and door locks. The Matter specification has provided a dedicated framework for managing them since 1.2, significantly expanded in 1.4 with Long Idle Time (LIT) support and the Check-In Protocol. Controller-side adoption of this framework has lagged across the ecosystem, and Home Assistant is no exception.
For users, the result is familiar: battery-powered Matter devices appearing as unavailable, automations failing to trigger, and no way to tell whether a device is genuinely offline or simply sleeping. Implementing ICD support in HA's controller means these devices become first-class citizens, reliably reachable when needed, correctly represented when sleeping, and no longer a source of unnecessary troubleshooting. Combined with Matter 1.6 spec currency, this positions Home Assistant as one of the most capable open Matter controllers available, and gives device manufacturers building battery-powered products a strong reason to validate and recommend it.
Community signals
Matter battery sensors going unavailable — repeated subscription liveness timeouts (GitHub, Jan 2026)
Multiple users report IKEA and other Matter battery sensors producing repeated "Subscription Liveness timeout" errors in the matter-server, causing sensors to appear unavailable in HA. The issue was filed across both the core and addons repositories and drew no developer response for weeks, indicating it as a known but unresolved systemic problem with how HA handles sleepy ICD devices today.
→ home-assistant/core#161437
Matter devices suddenly unavailable — random drops across multiple device brands (community.home-assistant.io, Apr 2026)
A user with 33 Matter devices reports random unavailability events affecting Aqara and IKEA devices simultaneously. The thread reflects a broader community pattern: battery-powered Matter devices falling offline in HA for reasons unrelated to actual device failure, pointing directly at the absence of a proper ICD-aware subscription and Check-In Protocol implementation.
→ https://community.home-assistant.io/t/matter-devices-suddenly-unavailable/1006018
Aqara P2 sensors switching to "unavailable" after commissioning (community.home-assistant.io, Jun 2024)
An early signal that has persisted into 2026: users successfully commissioning battery-powered Matter sensors, only to find them marking unavailable after a short time. This is the exact failure mode that proper LIT ICD and Check-In Protocol support in the controller is designed to prevent, and it predates any controller-side ICD implementation in HA.
→ https://community.home-assistant.io/t/aqara-p2-sensors-status-changes-to-unavailable/739099
No major ecosystem fully supports ICD, leaving battery devices under-managed (Matter Alpha, Dec 2025)
An analysis of ICD adoption across ecosystems confirmed that no major controller, at time of writing, fully supports the ICD Management cluster features from Matter 1.4. The piece notes this leaves low-power Matter devices less maintained and prone to unexpected battery drain, and explicitly calls out the risk of vendors being unable to confidently ship battery-powered Matter sensors until controller-side support matures.
→ https://www.matteralpha.com/news/google-and-apple-are-ready-to-optimize-your-battery-powered-sensors
Matter 1.6 released, HA confirmed at 1.5.1 with 1.6 flagged as coming soon (home-assistant.io, Jun 2026)
The official blog post announcing the matter.js-based Matter Server 9.0 explicitly states the server targets Matter 1.5.1 with Matter 1.6 coming soon. With 1.6 now released, there is a clear and near-term spec gap that needs closing for HA to remain a current controller, especially as device manufacturers certify against newer spec versions.
→ https://www.home-assistant.io/blog/2026/06/23/the-matter-upgrade-youve-been-waiting-for/
Scope & Boundaries
In scope
- Update the HA Matter Server (matter.js) to the Matter 1.6 specification
- Implement the ICD Management cluster on the controller side, enabling HA to register as a subscriber-aware controller for both SIT and LIT ICDs
- Implement the Check-In Protocol in the HA Matter controller so that battery-powered devices can re-establish communication with HA after subscription loss (e.g. after battery replacement, reboot, or network outage)
- Expose ICD-relevant device state in the HA UI where useful (e.g. distinguishing a sleeping ICD from a genuinely offline device)
- Validate ICD behavior against real battery-powered Matter devices (sensors, locks, buttons) across Thread and Wi-Fi transports
Not in scope
- Matter 1.6.x or future spec work
- ICD firmware implementation on device side (this is a controller-side opportunity)
- Changes to Zigbee, Z-Wave, or other protocol integrations
Foreseen solution
wip
Risks & open questions
wip
Appetite
Medium - 2-3 weeks
Execution issues
No response
Decision log
Problem statement
Matter 1.6 was released by the CSA on June 17, 2026. It is a focused feature release that refines device setup, multi-ecosystem coordination, and how devices communicate their capabilities and operational state. Key additions relevant to Home Assistant as a controller include NFC-Based Commissioning, Joint Fabric for multi-ecosystem device sharing, and standardized device capability communication. The HA Matter Server (matter.js) currently targets Matter 1.5.1, with 1.6 support confirmed as the next step.
Adopting Matter 1.6 is also the right moment to close a more fundamental gap in HA's controller implementation: proper support for ICDs (Intermittently Connected Devices). ICDs are the dominant form factor for battery-powered Matter devices, covering sensors, buttons, and door locks. The Matter specification has provided a dedicated framework for managing them since 1.2, significantly expanded in 1.4 with Long Idle Time (LIT) support and the Check-In Protocol. Controller-side adoption of this framework has lagged across the ecosystem, and Home Assistant is no exception.
For users, the result is familiar: battery-powered Matter devices appearing as unavailable, automations failing to trigger, and no way to tell whether a device is genuinely offline or simply sleeping. Implementing ICD support in HA's controller means these devices become first-class citizens, reliably reachable when needed, correctly represented when sleeping, and no longer a source of unnecessary troubleshooting. Combined with Matter 1.6 spec currency, this positions Home Assistant as one of the most capable open Matter controllers available, and gives device manufacturers building battery-powered products a strong reason to validate and recommend it.
Community signals
Matter battery sensors going unavailable — repeated subscription liveness timeouts (GitHub, Jan 2026)
Multiple users report IKEA and other Matter battery sensors producing repeated "Subscription Liveness timeout" errors in the matter-server, causing sensors to appear unavailable in HA. The issue was filed across both the core and addons repositories and drew no developer response for weeks, indicating it as a known but unresolved systemic problem with how HA handles sleepy ICD devices today.
→ home-assistant/core#161437
Matter devices suddenly unavailable — random drops across multiple device brands (community.home-assistant.io, Apr 2026)
A user with 33 Matter devices reports random unavailability events affecting Aqara and IKEA devices simultaneously. The thread reflects a broader community pattern: battery-powered Matter devices falling offline in HA for reasons unrelated to actual device failure, pointing directly at the absence of a proper ICD-aware subscription and Check-In Protocol implementation.
→ https://community.home-assistant.io/t/matter-devices-suddenly-unavailable/1006018
Aqara P2 sensors switching to "unavailable" after commissioning (community.home-assistant.io, Jun 2024)
An early signal that has persisted into 2026: users successfully commissioning battery-powered Matter sensors, only to find them marking unavailable after a short time. This is the exact failure mode that proper LIT ICD and Check-In Protocol support in the controller is designed to prevent, and it predates any controller-side ICD implementation in HA.
→ https://community.home-assistant.io/t/aqara-p2-sensors-status-changes-to-unavailable/739099
No major ecosystem fully supports ICD, leaving battery devices under-managed (Matter Alpha, Dec 2025)
An analysis of ICD adoption across ecosystems confirmed that no major controller, at time of writing, fully supports the ICD Management cluster features from Matter 1.4. The piece notes this leaves low-power Matter devices less maintained and prone to unexpected battery drain, and explicitly calls out the risk of vendors being unable to confidently ship battery-powered Matter sensors until controller-side support matures.
→ https://www.matteralpha.com/news/google-and-apple-are-ready-to-optimize-your-battery-powered-sensors
Matter 1.6 released, HA confirmed at 1.5.1 with 1.6 flagged as coming soon (home-assistant.io, Jun 2026)
The official blog post announcing the matter.js-based Matter Server 9.0 explicitly states the server targets Matter 1.5.1 with Matter 1.6 coming soon. With 1.6 now released, there is a clear and near-term spec gap that needs closing for HA to remain a current controller, especially as device manufacturers certify against newer spec versions.
→ https://www.home-assistant.io/blog/2026/06/23/the-matter-upgrade-youve-been-waiting-for/
Scope & Boundaries
In scope
Not in scope
Foreseen solution
wip
Risks & open questions
wip
Appetite
Medium - 2-3 weeks
Execution issues
No response
Decision log