# Composable

Artifact: [androidx.compose.runtime:runtime](https://developer.android.com/jetpack/androidx/releases/compose-runtime) [View Source](https://cs.android.com/search?q=file:androidx/compose/runtime/Composable.kt+class:androidx.compose.runtime.Composable) Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/compose-runtime#1.0.0) Common/AllAndroid/JVMNative/C/iOSJavaScript
- Cmn

  ```
  @MustBeDocumented
  @Retention(value = AnnotationRetention.BINARY)
  @Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.TYPE, AnnotationTarget.TYPE_PARAMETER, AnnotationTarget.PROPERTY_GETTER])
  annotation Composable
  ```

*** ** * ** ***

`https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` functions are the fundamental building blocks of an application built with Compose.

`https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` can be applied to a function or lambda to indicate that the function/lambda can be used as part of a composition to describe a transformation from application data into a tree or hierarchy.

Annotating a function or expression with `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` changes the type of that function or expression. For example, `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` functions can only ever be called from within another `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` function. A useful mental model for `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` functions is that an implicit "composable context" is passed into a `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` function, and is done so implicitly when it is called from within another `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable` function. This "context" can be used to store information from previous executions of the function that happened at the same logical point of the tree.

## Summary

| ### Public constructors |
|---|---|
| `https://developer.android.com/reference/kotlin/androidx/compose/runtime/Composable#Composable()()` | Cmn |

## Public constructors

### Composable

Cmn

```
Composable()
```