---
title: HMCharacteristicTypeActiveIdentifier
framework: homekit
role: symbol
role_heading: Global Variable
path: homekit/hmcharacteristictypeactiveidentifier
---

# HMCharacteristicTypeActiveIdentifier

An index that maps to the current active Input Source service.

## Declaration

```swift
let HMCharacteristicTypeActiveIdentifier: String
```

## Discussion

Discussion This characteristic describes the current input source of a television by referencing the HMServiceTypeInputSource. The Active Identifier characteristic’s value should be a valid value within the identifiers of the Input Source service instances linked to the television service. The value of the characteristic is a UInt32 integer.

## See Also

### Accessory identification

- [HMCharacteristicTypeName](homekit/hmcharacteristictypename.md)
- [HMCharacteristicTypeIdentify](homekit/hmcharacteristictypeidentify.md)
- [HMCharacteristicTypeVersion](homekit/hmcharacteristictypeversion.md)
- [HMCharacteristicTypeLogs](homekit/hmcharacteristictypelogs.md)
- [HMCharacteristicTypeAdminOnlyAccess](homekit/hmcharacteristictypeadminonlyaccess.md)
- [HMCharacteristicTypeHardwareVersion](homekit/hmcharacteristictypehardwareversion.md)
- [HMCharacteristicTypeSoftwareVersion](homekit/hmcharacteristictypesoftwareversion.md)
- [HMCharacteristicTypeLabelIndex](homekit/hmcharacteristictypelabelindex.md)
- [HMCharacteristicTypeLabelNamespace](homekit/hmcharacteristictypelabelnamespace.md)
- [HMCharacteristicTypeIdentifier](homekit/hmcharacteristictypeidentifier.md)
- [HMCharacteristicTypeInputDeviceType](homekit/hmcharacteristictypeinputdevicetype.md)
- [HMCharacteristicTypeInputSourceType](homekit/hmcharacteristictypeinputsourcetype.md)
- [HMCharacteristicTypeConfiguredName](homekit/hmcharacteristictypeconfiguredname.md)