> For the complete documentation index, see [llms.txt](https://docs.caf.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.caf.io/caf-sdk/ios/standalone-modules/caffaceauth/builder.md).

# Building the SDK

## Creating a FaceAuthSDK instance

To create a `FaceAuthSDK` instance, use the `Builder` class. This class provides a set of methods to configure the SDK instance.

### Builder Properties

| Property                 | Type       | Description                                                                 | Required |
| ------------------------ | ---------- | --------------------------------------------------------------------------- | :------: |
| `stage`                  | `CAFStage` | Defines the environment stage (e.g., `.prod`, `.beta`). Default is `.prod`. |     ❌    |
| `sessionId`              | `String`   | Session ID for the current authentication process.                          |     ✅    |
| `withLoading`            | `Bool`     | Indicates whether to show a loading screen. Default is `false`.             |     ❌    |
| `token`                  | `String`   | Authentication token required for the SDK.                                  |     ✅    |
| `filter`                 | `Filter`   | Defines the filter for liveness detection. Default is `.lineDrawing`.       |     ❌    |
| `personId`               | `String`   | Identifier for the person being authenticated. Default is an empty string.  |     ❌    |
| `imageUrlExpirationTime` | `Time`     | Expiration time for image URLs. Default is `.thirtyMin`.                    |     ❌    |

### Builder Methods

| Method                                   | Type       | Description                                                          | Required |
| ---------------------------------------- | ---------- | -------------------------------------------------------------------- | :------: |
| `setStage(stage:)`                       | `CAFStage` | Sets the environment stage for the SDK. Default is `.prod`.          |     ❌    |
| `setSessionId(sessionId:)`               | `String`   | Sets the session ID for the authentication process.                  |     ✅    |
| `setLoading(withLoading:)`               | `Bool`     | Configures whether a loading screen should be shown.                 |     ❌    |
| `setAuthBaseUrl(authBaseUrl:)`           | `String`   | Sets the base URL for authentication.                                |     ✅    |
| `setLivenessBaseUrl(livenessBaseUrl:)`   | `String`   | Sets the base URL for liveness detection.                            |     ✅    |
| `setFilter(filter:)`                     | `Filter`   | Configures the liveness detection filter. Default is `.lineDrawing`. |     ❌    |
| `setCertificates(certificates:)`         | `[String]` | Adds certificates required for secure communication.                 |     ✅    |
| `setImageUrlExpirationTime(time:)`       | `Time`     | Sets the expiration time for image URLs. Default is `.thirtyMin`.    |     ❌    |
| `.setCustomLocalization(named: String?)` | `String?`  | Sets the name of the Localization File for Iproov Strings            |     ❌    |

### Example

```swift
import FaceLiveness

let faceAuthSDK: FaceAuthSDK?

private func setupFaceAuthSDK() {
    faceAuthSDK = FaceAuthSDK.Builder()
        .setStage(stage: .prod)
        .setSessionId(sessionId: "session123")
        .setLoading(withLoading: true)
        .setAuthBaseUrl(authBaseUrl: "https://auth.example.com")
        .setLivenessBaseUrl(livenessBaseUrl: "https://liveness.example.com")
        .setFilter(filter: .lineDrawing)
        .setCertificates(certificates: ["cert1", "cert2"])
        .setImageUrlExpirationTime(time: .thirtyMin)
        .setCustomLocalization(named: "Iproov-strings-file-name")
        .build()
}
```


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