| Interface | Description | 
|---|---|
| DataLayout | The interface for message schema of a topic. | 
| Topic | An interface representing a topic under a schema  Namespace. | 
| TopicCatalog | The  TopicCataloginterface defines the public API for managing topic objects in a schema. | 
| TopicChange | A topic change is a change to a topic. | 
| Class | Description | 
|---|---|
| TopicChange.RemoveProperty | A topic change to remove a property from the topic. | 
| TopicChange.SetProperty | A topic change to set or update the property and value for the topic. | 
| TopicChange.UpdateTopicComment | A topic change to update the topic comment. |