# GrainCallFrequency.SourceGrain

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.graincallfrequency/) | [Properties](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.graincallfrequency/properties/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/SystemTargetInterfaces/IManagementGrain.cs)

```csharp
[Orleans.Id(0)]
public GrainId SourceGrain
```

The source grain.