> ## Documentation Index
> Fetch the complete documentation index at: https://docs.posetracker.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Permissions

> The host app declares and requests camera access — the SDK does not ship permission copy.

The SDK opens the camera via **`getUserMedia` inside `WebViewPoseView`** when `coldStart` is `full` (default on the camera screen). It does **not** ship iOS/Android permission strings — **your app must declare and request camera access**.

## Responsibility split

| Layer                        | Who          | What                                                           |
| ---------------------------- | ------------ | -------------------------------------------------------------- |
| Usage description + manifest | **Host app** | `NSCameraUsageDescription`, Android `CAMERA`, Expo plugin text |
| When to ask                  | **Host app** | Prefer on (or just before) the camera screen                   |
| `getUserMedia`               | **SDK**      | On `<WebViewPoseView />` with `coldStart="full"`               |
| Model-only warm-up           | **SDK**      | `preload()` + `coldStart="basic"` — **no** permission          |

## Expo

### Declare

```json theme={null}
{
  "expo": {
    "ios": {
      "infoPlist": {
        "NSCameraUsageDescription": "Camera access is required for on-device pose estimation."
      }
    },
    "android": {
      "permissions": ["android.permission.CAMERA"]
    },
    "plugins": [
      [
        "expo-camera",
        {
          "cameraPermission": "Camera access is required for on-device pose estimation."
        }
      ]
    ]
  }
}
```

Use your own product wording. Rebuild after changing plugins (`npx expo prebuild` / EAS).

### Request, then mount

```tsx theme={null}
import { useEffect } from 'react';
import { Text, View } from 'react-native';
import { useCameraPermissions } from 'expo-camera';
import { WebViewPoseView } from '@pose-tracker/react-native-pose-estimation';

export function CameraScreen() {
  const [permission, requestPermission] = useCameraPermissions();

  useEffect(() => {
    if (permission && !permission.granted && permission.canAskAgain) {
      void requestPermission();
    }
  }, [permission, requestPermission]);

  if (!permission?.granted) {
    return (
      <View style={{ flex: 1, justifyContent: 'center', padding: 24 }}>
        <Text>Camera permission is required for pose tracking.</Text>
      </View>
    );
  }

  return <WebViewPoseView style={{ flex: 1 }} drawSkeleton />;
}
```

## Bare React Native

**iOS** — `Info.plist`:

```xml theme={null}
<key>NSCameraUsageDescription</key>
<string>Camera access is required for on-device pose estimation.</string>
```

**Android** — `AndroidManifest.xml`:

```xml theme={null}
<uses-permission android:name="android.permission.CAMERA" />
```

Request at runtime (API 23+) before mounting `WebViewPoseView`.

## Cold-start tip

| Mode      | API                               | Camera permission              |
| --------- | --------------------------------- | ------------------------------ |
| **basic** | `preload()` / `coldStart="basic"` | No — model / WebGL only        |
| **full**  | `preload({ coldStart: 'full' })`  | Yes — when user expects camera |

Lobby warmer: `<WebViewPoseView coldStart="basic" />`. Camera screen: default `full`.

Full lifecycle: [Preload](/advanced/preload).

## Checklist

1. Declare iOS usage string (+ Expo plugin text).
2. Declare Android `CAMERA`.
3. Request permission on the camera screen.
4. Mount `WebViewPoseView` only when granted (or handle denial UX).
5. Never call `preload({ coldStart: 'full' })` outside a camera context the user expects.