# createRecordingClient (/docs/api/core-testing/functions/createRecordingClient)



```ts
function createRecordingClient(
   inner, 
   sink, 
   options?
): SystemOneClient;
```

Wraps a live client and hands one replay line per call to `sink`. The live test's half.

## Parameters [#parameters]

| Parameter | Type                                                                     |
| --------- | ------------------------------------------------------------------------ |
| `inner`   | [`SystemOneClient`](/docs/api/core/interfaces/SystemOneClient)           |
| `sink`    | (`line`) => `void`                                                       |
| `options` | [`RecordingOptions`](/docs/api/core-testing/interfaces/RecordingOptions) |

## Returns [#returns]

[`SystemOneClient`](/docs/api/core/interfaces/SystemOneClient)