> ## Documentation Index
> Fetch the complete documentation index at: https://primer.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# configure

After creating an instance of the `PrimerHeadlessUniversalCheckout.VaultManager` you must call configure
which will validate the session and notify you if anything is wrong.

```swift SWIFT theme={"dark"}
func configure() throws
```

## Throws

<Expandable defaultOpen title="Throws">
  <ResponseField name="uninitializedSDKSession">
    An error that will be thrown in case the SDK was not initialized properly. Before calling this method,
    the SDK must be initialized.
  </ResponseField>

  <ResponseField name="invalidClientSessionValue">
    An error that will be thrown in case the client session is missing some required fields.
  </ResponseField>
</Expandable>