# IPurgeObservable.Oldest

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ipurgeobservable/) | [Properties](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ipurgeobservable/properties/)

```csharp
public abstract CachedMessage? Oldest
```

Gets the oldest message in the cache.