# GrainIdKeyExtensions.CreateGuidKey(Guid, string?)

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

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core.Abstractions/IDs/GrainIdKeyExtensions.cs)

```csharp
public static IdSpan CreateGuidKey(Guid key, string? keyExtension)
```

Creates an [IdSpan](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleans.runtime.idspan/) representing a `System.Guid` key and key extension string.

### Parameters

- `key` (`Guid`): The key.
- `keyExtension` (`string?`): The key extension.

### Returns

An [IdSpan](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleans.runtime.idspan/) representing the provided key and key extension.