Function Signature 
@available(iOS 16, *)
public func setPasskeyAuthenticationAnchor(
    _ anchor: ASPresentationAnchor
) throws
Parameters
  • anchor: The window anchor where passkey authentication UI will be presented. This is typically the main window of your application and should be of type ASPresentationAnchor (which UIWindow conforms to).
Platform Availability
  • Requires iOS 16.0 or later
  • Part of the native passkey implementation in iOS
Notes
  • Must be called before using passkey backup or recovery methods
  • Should be used in conjunction with setPasskeyConfiguration for complete setup
  • The anchor is used to present the system’s native passkey authentication dialog
Example Usage 
// Basic usage in UIKit
if #available(iOS 16, *) {
    do {
        // Set the authentication anchor using the main window
        try portal.setPasskeyAuthenticationAnchor(view.window!)
    } catch {
        print("Error setting passkey authentication anchor: \(error)")
    }
}

// Complete setup in UIViewController
class MyViewController: UIViewController {
    func setupPasskeys() {
        if #available(iOS 16, *) {
            do {
                // Configure passkey settings
                try portal.setPasskeyConfiguration(
                    relyingParty: "portalhq.io",
                    webAuthnHost: "backup.web.portalhq.io"
                )

                // Set the authentication anchor
                guard let window = view.window else {
                    print("Error: No window available")
                    return
                }
                try portal.setPasskeyAuthenticationAnchor(window)

                print("Passkey authentication setup complete")
            } catch {
                print("Error setting up passkey authentication: \(error)")
            }
        }
    }
}

// Usage in SwiftUI
import SwiftUI

struct PasskeyView: View {
    @Environment(\.window) var window: UIWindow?

    func setupPasskeyAuth() {
        if #available(iOS 16, *) {
            do {
                guard let window = window else {
                    print("Error: No window available")
                    return
                }
                try portal.setPasskeyAuthenticationAnchor(window)
            } catch {
                print("Error setting passkey authentication anchor: \(error)")
            }
        }
    }

    var body: some View {
        Text("Passkey Setup")
            .onAppear {
                setupPasskeyAuth()
            }
    }
}
Implementation Guide
  1. Ensure you’re running on iOS 16 or later
  2. Call setPasskeyConfiguration first to set up basic passkey settings
  3. Obtain a reference to your app’s main window or appropriate presentation context
  4. Call this method with the window reference
  5. Now you can use passkey-based authentication features
UI Considerations
  • The passkey dialog will be presented as a system modal over your application
  • The presentation anchor should be stable and available throughout the authentication process
  • For best user experience, call this method when your view hierarchy is fully established
Related Documentation For more information about passkey, see: