# SystemTarget.GetExtension

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L335-L347)

```csharp
public TExtensionInterface GetExtension<TExtensionInterface>()
```

Returns the grain extension registered for the provided `TExtensionInterface`.

### Returns

The implementation of the extension which is bound to this grain.