Camera & Permissions

Handle camera permissions correctly in your iOS app when using the Circadify SDK.

The Circadify SDK requires camera access — the front (selfie) camera by default, or the rear camera when you create it with CircadifyCamera(position: .back). The permission flow is identical either way. iOS enforces strict permission controls — your app must handle the permission flow before starting a measurement.

Info.plist

Add the camera usage description to your Info.plist. Without this, iOS will terminate your app on camera access.

<key>NSCameraUsageDescription</key>
<string>This app uses the camera to measure your vital signs contactlessly.</string>

Write a clear, specific description. Vague descriptions like "Camera access needed" may cause App Store review rejection.

Permission Flow

Permissions are handled through CircadifyCamera — the object that owns the shared capture session for both the live preview and the measurement.

In the simplest case you don't manage permissions yourself at all — just call camera.start() in a .task and let it prompt:

import SwiftUI
import CircadifySDK
 
struct ScanView: View {
    @State private var camera = CircadifyCamera()
 
    var body: some View {
        CircadifyCameraPreview(camera: camera)
            .ignoresSafeArea()
            .task {
                try? await camera.start()   // requests permission if needed, then goes live
            }
            .onDisappear { camera.stop() }
    }
}

When you want to react to denial — for example to deep-link the user into Settings — observe camera.authorizationStatus and surface an alert.

import SwiftUI
import CircadifySDK
 
struct ScanView: View {
    @State private var camera = CircadifyCamera()
    @State private var showSettingsAlert = false
    @Environment(\.scenePhase) private var scenePhase
 
    var body: some View {
        ZStack {
            CircadifyCameraPreview(camera: camera)
                .ignoresSafeArea()
 
            if !camera.isRunning {
                Text("Camera access is required to scan.")
                    .foregroundStyle(.white)
            }
        }
        .alert("Camera Access Required", isPresented: $showSettingsAlert) {
            Button("Open Settings") {
                if let url = URL(string: UIApplication.openSettingsURLString) {
                    UIApplication.shared.open(url)
                }
            }
            Button("Cancel", role: .cancel) { }
        } message: {
            Text("Go to Settings > Privacy > Camera and enable access for this app.")
        }
        .task { await start() }
        .onChange(of: scenePhase) { _, phase in
            // Returning from Settings — retry if the user just enabled access.
            if phase == .active, !camera.isRunning {
                Task { await start() }
            }
        }
        .onDisappear { camera.stop() }
    }
 
    func start() async {
        do {
            try await camera.start()   // prompts if .notDetermined, then goes live
        } catch CircadifyError.cameraPermissionDenied {
            showSettingsAlert = true
        } catch {
            print("Camera failed to start: \(error)")
        }
    }
}

Best Practices

• Let start() do the work. camera.start() requests permission automatically when the status is .notDetermined, so you rarely need to call requestAccess() yourself. Catch CircadifyError.cameraPermissionDenied to handle the denied case.
• Request early. Trigger the prompt during onboarding or as soon as the scan screen appears, not at the last moment before measuring.
• Handle denial gracefully. Provide a clear path to Settings with a direct deep link (UIApplication.openSettingsURLString).
• Re-check on foreground. After the user returns from Settings, re-check on scenePhase == .active (SwiftUI) or didBecomeActiveNotification (UIKit) and retry camera.start().
• Stop when off-screen. Call camera.stop() in onDisappear / viewDidDisappear to release the capture session.

Next Steps

• Methods — Start a measurement
• Error Handling — Handle permission-related errors
• Configuration — SDK setup options