# OptIn

Artifact: [androidx.annotation:annotation-experimental](https://developer.android.com/jetpack/androidx/releases/annotation) [View Source](https://cs.android.com/search?q=file:androidx/annotation/OptIn.kt+class:androidx.annotation.OptIn) Added in [1.1.0](https://developer.android.com/jetpack/androidx/releases/annotation#1.1.0)

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```
@Retention(value = AnnotationRetention.BINARY)
@Target(allowedTargets = [AnnotationTarget.CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.LOCAL_VARIABLE, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.CONSTRUCTOR, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.FILE, AnnotationTarget.TYPEALIAS])
@Target(value = [ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.LOCAL_VARIABLE, ElementType.METHOD, ElementType.PACKAGE, ElementType.TYPE, ElementType.PARAMETER])
public annotation OptIn
```

<br />

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Allows use of an opt-in API denoted by the given markers in the annotated file, declaration, or expression. If a declaration is annotated with `https://developer.android.com/reference/androidx/annotation/OptIn`, its usages are **not** required to opt-in to that API.

## Summary

| ### Public methods |
|---|---|
| `final @https://developer.android.com/reference/androidx/annotation/NonNull KClass[]` | `https://developer.android.com/reference/androidx/annotation/OptIn#getMarkerClass()()` Defines the opt-in API(s) whose usage this annotation allows. |

## Public methods

### getMarkerClass

```
public final @NonNull KClass[] getMarkerClass()
```

Defines the opt-in API(s) whose usage this annotation allows.