# ConnectionPropertyAnnotation

- Kind: `class`
- Package: [Aspire.Hosting](/reference/api/csharp/aspire.hosting.md)
- Version: `13.3.0`
- Namespace: `Aspire.Hosting.ApplicationModel`
- Target framework: `net8.0`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/bd20f904cde09ecb9c9ae5116a6f13614bf2d7c2/src/Aspire.Hosting/ApplicationModel/ConnectionPropertyAnnotation.cs)
- Implements: [IResourceAnnotation](/reference/api/csharp/aspire.hosting/iresourceannotation.md)

Annotation that creates a custom connection property value injected into environment variables when a resource is referenced using `WithReference()`.

## Definition

```csharp
namespace Aspire.Hosting.ApplicationModel;

public sealed class ConnectionPropertyAnnotation
    : Aspire.Hosting.ApplicationModel.IResourceAnnotation
{
    // ...
}
```

## Constructors

- [ConnectionPropertyAnnotation(string, ReferenceExpression)](/reference/api/csharp/aspire.hosting/connectionpropertyannotation/constructors.md#constructor-string-referenceexpression) -- Initializes a new instance of the ConnectionPropertyAnnotation class with the specified property name and reference expression.

## Properties

- [Name](/reference/api/csharp/aspire.hosting/connectionpropertyannotation/properties.md#name) : `string` `get` -- Gets the name associated with the current instance.
- [Value](/reference/api/csharp/aspire.hosting/connectionpropertyannotation/properties.md#value) : [ReferenceExpression](/reference/api/csharp/aspire.hosting/referenceexpression.md) `get` -- Gets the reference expression associated with this instance.