# TestClusterExtensions.GetConfigurationValue(IHostBuilder, string)

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

[Source](https://github.com/dotnet/orleans/blob/b7a9e3e1c9c54b3cec3a467c5734bf7744541bcf/src/Orleans.TestingHost/TestClusterExtensions.cs#L38)

```csharp
public static string? GetConfigurationValue(this IHostBuilder hostBuilder, string key)
```

Gets a configuration value.

### Parameters

- `hostBuilder` (`IHostBuilder`): The host builder.
- `key` (`string`): The key.

### Returns

The configuration value.