# ILifecycleSubject

Package: [Microsoft.Orleans.Core.Abstractions](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/) 10.0.0

[NuGet package](https://www.nuget.org/packages/Microsoft.Orleans.Core.Abstractions)

```csharp
public interface ILifecycleSubject : ILifecycleObservable, ILifecycleObserver
```

Both a lifecycle observer and observable lifecycle.