# IAsyncObserver<T>.OnCompletedAsync

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.iasyncobserver-1/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.streams.iasyncobserver-1/methods/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Core/IAsyncObserver.cs#L47)

```csharp
public virtual Task OnCompletedAsync()
```

Notifies the consumer that the stream was completed. 

The Task returned from this method should be completed when the consumer is done processing the stream closure.

### Returns

A Task that is completed when the stream-complete operation has been accepted.