# ObsoleteData Properties

- Package: [Aspire.TypeSystem](/reference/api/csharp/aspire.typesystem.md)
- Type: [ObsoleteData](/reference/api/csharp/aspire.typesystem/obsoletedata.md)
- Kind: `Properties`
- Members: `2`

Name-based adapter for `ObsoleteAttribute` data, parsed from `Reflection.CustomAttributeData`.

## IsError

- Name: `IsError`
- Modifiers: `get; init`
- Returns: `bool`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/a3766e994fd2cba86c8ac60b8a80268cab7e6383/src/Aspire.TypeSystem/AttributeDataReader.cs)

Gets whether use of the obsolete API is an error.

```csharp
public bool IsError { get; init; }
```

## Message

- Name: `Message`
- Modifiers: `nullable` `get; init`
- Returns: `string?`
- Source: [GitHub](https://github.com/microsoft/aspire/blob/a3766e994fd2cba86c8ac60b8a80268cab7e6383/src/Aspire.TypeSystem/AttributeDataReader.cs)

Gets the obsolete message, if any.

```csharp
public string? Message { get; init; }
```