facebook/sample-app-guide
Building a complete DAT app with camera streaming and photo capture
npx skills add https://github.com/facebook/meta-wearables-dat-ios --skill sample-app-guide
Build an iOS DAT app with camera streaming and photo capture.
This walkthrough covers app setup, registration, streaming, and capture. Pair it with the CameraAccess sample.
https://github.com/facebook/meta-wearables-dat-iosMWDATCore, MWDATCamera, and MWDATMockDevice to your targetInfo.plist (see Getting Started)A typical DAT app has these components:
MyDATApp/
├── MyDATApp.swift # App entry point, SDK init
├── ViewModels/
│ ├── WearablesViewModel.swift # Registration, device management
│ └── StreamViewModel.swift # Streaming, photo capture
└── Views/
├── MainAppView.swift # Navigation
├── RegistrationView.swift # Registration UI
└── StreamView.swift # Video preview, capture button
import MWDATCore
@main
struct MyDATApp: App {
init() {
do {
try Wearables.configure()
} catch {
assertionFailure("Wearables SDK configuration failed: \(error)")
}
}
var body: some Scene {
WindowGroup {
MainAppView()
.onOpenURL { url in
Task {
_ = try? await Wearables.shared.handleUrl(url)
}
}
}
}
}
import MWDATCore
@MainActor
class WearablesViewModel: ObservableObject {
@Published var registrationState: String = "Unknown"
@Published var devices: [DeviceIdentifier] = []
private let wearables = Wearables.shared
func observeState() {
Task {
for await state in wearables.registrationStateStream() {
self.registrationState = "\(state)"
}
}
Task {
for await devices in wearables.devicesStream() {
self.devices = devices.map { $0.identifier }
}
}
}
func register() async {
try? await wearables.startRegistration()
}
func unregister() async {
try? await wearables.startUnregistration()
}
}
import MWDATCamera
import MWDATCore
@MainActor
class StreamViewModel: ObservableObject {
@Published var currentFrame: UIImage?
@Published var streamState: String = "Stopped"
@Published var capturedPhoto: Data?
private let wearables = Wearables.shared
private var deviceSession: DeviceSession?
private var camera: Camera?
private var stream: Stream?
func startStream() async {
let config = StreamConfiguration(
videoCodec: .raw,
resolution: .medium,
frameRate: 24
)
let selector = AutoDeviceSelector(wearables: wearables)
do {
let deviceSession = try wearables.createSession(deviceSelector: selector)
try deviceSession.start()
// Wait for the device session to reach the started state
for await state in deviceSession.stateStream() {
if state == .started { break }
}
guard let camera = try deviceSession.addCamera(config: config) else { return }
let stream = camera.stream
self.deviceSession = deviceSession
self.camera = camera
self.stream = stream
} catch {
return
}
guard let stream else { return }
_ = stream.statePublisher.listen { [weak self] state in
Task { @MainActor in
self?.streamState = "\(state)"
}
}
_ = stream.videoFramePublisher.listen { [weak self] frame in
guard let image = frame.makeUIImage() else { return }
Task { @MainActor in
self?.currentFrame = image
}
}
_ = stream.photoDataPublisher.listen { [weak self] photoData in
Task { @MainActor in
self?.capturedPhoto = photoData.data
}
}
stream.start()
}
func stopStream() {
camera?.stop()
deviceSession?.stop()
stream = nil
camera = nil
deviceSession = nil
}
func capturePhoto() {
stream?.capturePhoto(format: .jpeg)
}
}
Add mock device support to develop without glasses:
import MWDATMockDevice
func setupMockDevice() async {
let mockDeviceKit = MockDeviceKit.shared
mockDeviceKit.enable()
guard let device = try? mockDeviceKit.pairGlasses(model: .rayBanMeta) else { return }
device.don()
if let videoURL = Bundle.main.url(forResource: "test_video", withExtension: "mov") {
let camera = device.services.camera
camera.setCameraFeed(fileURL: videoURL)
}
}
func tearDownMockDevice() {
MockDeviceKit.shared.disable()
}
Your DAT app should only depend on:
MWDATCore — always requiredMWDATCamera — for camera streamingMWDATMockDevice — for testing (can be test-only dependency)Take facebook/sample-app-guide from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.