# HealthCheckAnnotation Properties

- Package: [Aspire.Hosting](/reference/api/csharp/aspire.hosting.md)
- Type: [HealthCheckAnnotation](/reference/api/csharp/aspire.hosting/healthcheckannotation.md)
- Kind: `Properties`
- Members: `1`

An annotation which tracks the name of the health check used to detect to health of a resource.

## Key

- Name: `Key`
- Modifiers: `get`
- Returns: `string`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/bd20f904cde09ecb9c9ae5116a6f13614bf2d7c2/src/Aspire.Hosting/ApplicationModel/HealthCheckAnnotation.cs#L18)

The key for the health check in the app host which associated with this resource.

```csharp
public string Key { get; }
```