<!--
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    "DriverKit: 21.0 -"
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  "documentType" : "symbol",
  "framework" : "AudioDriverKit",
  "identifier" : "/documentation/AudioDriverKit/IOUserAudioDriver/NewUserClient",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
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    "kind" : "Instance Method",
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    "preciseIdentifier" : "c:@S@IOUserAudioDriver@F@NewUserClient#i#**$@S@IOUserClient#"
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  "title" : "NewUserClient"
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-->

# NewUserClient

Requests the creation of a new user client for the service.

```
virtual kern_return_t NewUserClient(uint32_t in_type, IOUserClient **out_user_client);
```

## Parameters

`in_type`

The type passed to <doc://com.apple.documentation/documentation/iokit/1514515-ioserviceopen>.

`out_user_client`

A pointer to a variable for returning the new user client object. Upon the successful creation of the user client object, assign it to this variable.

## Return Value

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. For a list of error codes, see <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

## Discussion

Override this method if your service supports communication though an external user client. When an app calls <doc://com.apple.documentation/documentation/iokit/1514515-ioserviceopen> to start a new service, the system calls this method on the service passed to that function. In your implementation, call the <doc://com.apple.documentation/documentation/DriverKit/IOService/Create> method to create a new <doc://com.apple.documentation/documentation/DriverKit/IOUserClient> object for your service and return that object in the `userClient` parameter.

---

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