# Sample App Guide

> Building a complete DAT app with session creation, camera streaming, and photo capture

- Skill: `facebook/sample-app-guide` (Agent Skill)
- Install (CLI): `npx skillmds@latest add facebook/sample-app-guide`
- Raw SKILL.md: https://api.skillmd.com/api/skills/facebook/sample-app-guide/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: facebook (https://skillmd.com/u/facebook)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/facebook/sample-app-guide

---


# Sample App Guide (Android)

Build an Android DAT app with registration, sessions, camera streaming, and photo capture.

Pair this with the [CameraAccess sample](https://github.com/facebook/meta-wearables-dat-android/tree/main/samples).

## Project setup

1. Create an Android Studio app project.
2. Add the DAT Maven repository and dependencies.
3. Configure `AndroidManifest.xml` for registration callbacks plus `APPLICATION_ID` and `CLIENT_TOKEN`.
4. Initialize `Wearables` in your `Application`.

## Suggested app structure

```text
app/src/main/java/com/example/myapp/
├── MyApplication.kt
├── MainActivity.kt
├── session/
│   └── SessionViewModel.kt
└── ui/
    ├── RegistrationScreen.kt
    └── CameraScreen.kt
```

## Registration and session creation

```kotlin
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        lifecycleScope.launch {
            Wearables.registrationState.collect { state ->
                // Update registration UI
            }
        }
    }

    fun register() {
        Wearables.startRegistration(this)
    }
}
```

```kotlin
class SessionViewModel : ViewModel() {
    private var session: Session? = null
    private var camera: Camera? = null

    fun startCameraSession() {
        val createdSession = Wearables.createSession(AutoDeviceSelector()).getOrElse { error ->
            throw IllegalStateException(error.description)
        }
        createdSession.start()
        session = createdSession

        camera = createdSession.addCamera(
            StreamConfiguration(videoQuality = VideoQuality.MEDIUM, frameRate = 24),
        ).getOrElse { error ->
            throw IllegalStateException(error.description)
        }.also { addedCamera ->
            addedCamera.stream.start().getOrElse { error ->
                throw IllegalStateException(error.description)
            }
        }
    }
}
```

## Observe frames and capture photos

```kotlin
viewModelScope.launch {
    camera?.stream?.videoStream?.collect { frame ->
        // Render preview
    }
}

fun capturePhoto() {
    viewModelScope.launch {
        camera?.stream?.capturePhoto()
            ?.onSuccess { photoData ->
                savePhoto(photoData.data)
            }
            ?.onFailure { error, _ ->
                showCaptureError(error.description)
            }
    }
}
```

## Shutdown

```kotlin
fun stopCameraSession() {
    camera?.stop()
    session?.stop()
    camera = null
    session = null
}
```

## Testing with MockDeviceKit

Use `MockDeviceKit` to simulate linking glasses, permission state, and camera media without physical hardware. See [MockDevice Testing](mockdevice-testing.md) for setup details.

## Links

- [CameraAccess sample](https://github.com/facebook/meta-wearables-dat-android/tree/main/samples)
- [Android integration guide](https://wearables.developer.meta.com/docs/build-integration-android)
- [Developer documentation](https://wearables.developer.meta.com/docs/develop/)