# Can ‘register Capability’ use custom capabilities and attributes other than Cluster.Attribute？

**URL:** <https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271>\
**Category:** Developers\
**Tags:** zigbee\
**Created:** [July 23, 2025, 8:13pm UTC](https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271 "2025-07-23T20:13:35Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Script\_Zhu](https://avatars.discourse-cdn.com/v4/letter/s/e99b99/32.png) [@Script\_Zhu](https://community.homey.app/u/Script_Zhu)\
**Post date:** [July 23, 2025, 8:13pm UTC](https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271/1 "2025-07-23T20:13:36Z")

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This is the standard 0x0B04’s 0x0505 voltage, which can be used correctly. However, Homey currently only supports single-phase/A-phase. If I want to bind the 0x0905 voltage Phase B to my custom capability, is that possible? I’ve tried using a custom capability, and during debugging, it always prompts Error: ‘onNodeInit()’ failed, reason: Error: capability\_id\_not\_available\_on\_device.  
`this.registerCapability('measure_voltage', CLUSTER.ELECTRICAL_MEASUREMENT, { get: 'rmsVoltage', report: 'rmsVoltage', reportParser(value) { return value / 100; } });`

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**Author:** ![user3951](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/user3951/32/137264_2.png) [@user3951](https://community.homey.app/u/user3951)\
**Post date:** [July 23, 2025, 9:39pm UTC](https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271/2 "2025-07-23T21:39:18Z")

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If I understand you correctly, you want to create a custom capability that retrieves its value from another existing capability?

If that’s the case, it’s definitely possible using the [Device Capabilities](https://homey.app/en-no/app/nl.qluster-it.DeviceCapabilities/Device-Capabilities/) app. It allows you to link and transform values from one capability to another.

You might find [this](https://community.homey.app/t/support-eva-smart-whole-household-energy-meter/140098/4) thread helpful as a reference or guide

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**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [July 24, 2025, 4:42am UTC](https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271/3 "2025-07-24T04:42:31Z")

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> [@user3951](#):
>
> If I understand you correctly, you want to create a custom capability that retrieves its value from another existing capability?

You understand incorrectly.

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**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\
**Post date:** [July 24, 2025, 4:43am UTC](https://community.homey.app/t/can-register-capability-use-custom-capabilities-and-attributes-other-than-cluster-attribute/140271/4 "2025-07-24T04:43:51Z")

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The capability has to exist on the device before you can use it. If you added this capability to the app for already existing devices, you first need to use [`addCapability()`](https://apps-sdk-v3.developer.homey.app/Device.html#addCapability).