---
title: "Stable"
description: "Stable is used to communicate some guarantees to the compose compiler about how a certain type or
function will behave.

When applied to a class or an interface, [Stable] indicates that the following must be true:
1) The result of [equals] will always return the same result for the same two instances.
2) When a public property of the type changes, composition will be notified.
3) All public property types are stable.

When applied to a function or a property, the [Stable] annotation indicates that the function
will return the same result if the same parameters are passed in. This is only meaningful if the
parameters and results are themselves [Stable], [Immutable], or primitive.

The invariants that this annotation implies are used for optimizations by the compose compiler,
and have undefined behavior if the above assumptions are not met. As a result, one should not use
this annotation unless they are certain that these conditions are satisfied."
type: "class"
---

<div class='type'>Class</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>


```kotlin
@MustBeDocumented
@Target(
    AnnotationTarget.CLASS,
    AnnotationTarget.FUNCTION,
    AnnotationTarget.PROPERTY_GETTER,
    AnnotationTarget.PROPERTY,
)
@StableMarker
public annotation class Stable
```


Stable is used to communicate some guarantees to the compose compiler about how a certain type or
function will behave.

When applied to a class or an interface, `Stable` indicates that the following must be true:
1) The result of `equals` will always return the same result for the same two instances.
2) When a public property of the type changes, composition will be notified.
3) All public property types are stable.

When applied to a function or a property, the `Stable` annotation indicates that the function
will return the same result if the same parameters are passed in. This is only meaningful if the
parameters and results are themselves `Stable`, `Immutable`, or primitive.

The invariants that this annotation implies are used for optimizations by the compose compiler,
and have undefined behavior if the above assumptions are not met. As a result, one should not use
this annotation unless they are certain that these conditions are satisfied.