One Matter device, several apps (multi-admin)
Matter lets one device join Apple Home, Google Home, Alexa, SmartThings and Home Assistant at the same time. Official docs checked 2026-10-16; items marked Med come from manufacturer guidance, not platform docs.
Fabrics, simply
- A fabric is a private virtual network of Matter devices and controllers, run by one administrator (a hub or app). A device can be on one or more fabrics at once; apps often call fabrics "services" or "connected services" (CSA).
- Each controller keeps its own fabric; you can add a device directly or share it from another fabric (HA Matter docs).
- You need a Matter hub/controller for each platform you want to control the device from (Google Home help 13127223; CSA). See Hubs & Thread.
- Changes sync: turn a light off in Google Home and the other app shows "off" too (Google Home help 13127223).
How many platforms?
Home Assistant says the standard requires each device to support at least 5 fabrics at once (HA Matter docs). SmartThings says each device can connect to 5 services; past that you must remove one first (SmartThings support). Some devices may support more — check the maker.
The rule people miss: don't reuse the box code
The QR/setup code on the device is for first setup or after a factory reset. To add a second platform, open the app the device is already in and make a new temporary pairing code there (Amazon help). Amazon notes most people don't realize this, and each app hides the option in a different place (Amazon dev: commissioning best practices).
Where to make the sharing code
| Device is already in | Path | Code life | Source |
|---|---|---|---|
| Apple Home | Accessory settings → Turn On Pairing Mode → Copy Code | 5 min (Med) | TP-Link FAQ 3651 |
| Google Home | Touch and hold tile → Settings → Linked Matter apps & services → Link apps & services (or Use pairing code / Share with QR code) | 3 min (Med) | Google Home help 13127223; TP-Link FAQ 3651 |
| Alexa | Devices → device → Other Assistants and Apps → Add another (11-digit code) | 15 min | Amazon help |
| SmartThings | Device → More (⋮) → Share with other services → Share device (QR + setup code) | 15 min (Med) | SmartThings support; TP-Link FAQ 3651 |
| Home Assistant | Settings → Connectivity → Matter → Devices → device → Share device | Not stated | HA Matter docs |
Then in the second app, add a new device/accessory and enter or scan that code. Apple: Add Accessory → More options lists accessories already paired to other apps (Apple 102135). HA: Add device → "Yes. It's already in use." (HA Matter docs).
Common failure modes
- Used the printed code — it won't work for a second platform; generate a sharing code (Amazon help; Amazon dev: commissioning best practices).
- "Already commissioned" / "Ready to pair" but fails — Amazon lists these as common errors when adding to a new admin (Amazon dev: commissioning best practices).
- Code expired — finish before it times out; keep the first app's code screen open (Med, TP-Link FAQ 3651).
- Made codes in two apps back to back — while the first code is open, later codes are invalid (Med, TP-Link FAQ 3651).
- Fabric limit hit — SmartThings will ask you to remove a connected service once 5 are used (SmartThings support).
- No hub for the second platform — each app needs its own Matter hub (Google Home help 13127223).
- Network issues — Matter needs local IPv6 and mDNS to flow; VLANs, multicast filtering or broken IGMP snooping can break adding or control (HA Matter docs). Google requires IPv6 on the home router (Google Home help 13127223).
- Thread OTA via HA behind Apple border routers — HA Matter updates fail ("Target node did not process the update file") (HA Matter docs).
Removing a platform
- Apple: Settings → General → Matter Accessories → accessory → remove from one connected service, all services, or Keychain (Apple 102135).
- HA: device → ⋮ → Manage fabrics → remove the controller; for Apple Home also remove the Keychain entry (HA Matter docs).
- SmartThings: remove from the third-party app's side (SmartThings support).
- Google: Remove device in Google Home; Google suggests a factory reset if you stop using it (Google Home help 13127223).
Feature gaps
Sharing gives every platform the same Matter device, but not every platform supports every Matter device type or feature, and timing differs (matrix; Google Home help 13127223). Native integrations can beat Matter — e.g. Hue over Matter gives only basic light control in HA (HA Matter docs).
Not covered: per-platform fabric limits beyond SmartThings (not documented by Apple, Google, Amazon), and Thread network credential sharing. Not device-tested by us.