# SubgraphAttribute(Type)

> Initializes a new instance of the SubgraphAttribute class.

## Definition

* **Type:** Constructor
* **Namespace:** [Unity.GraphToolkit.Editor](/engine/6000.5/script-reference/unity/graphtoolkit/editor.md)
* **Assembly:** UnityEditor

```csharp
public SubgraphAttribute(Type mainGraphType)
```

### Parameters

**** (\[Type]\(https\://learn.microsoft.com/dotnet/api/system.type)): The type of the main [Graph](/engine/6000.5/script-reference/unity/graphtoolkit/editor/graph.md) that this subgraph type is compatible with. This must be a type that inherits from [Graph](/engine/6000.5/script-reference/unity/graphtoolkit/editor/graph.md).

### Remarks

Use this constructor to associate a custom subgraph class with a parent graph type. This enables the graph tool to recognize the subgraph as a valid option for the specified main graph. The attribute must be applied to a [Graph](/engine/6000.5/script-reference/unity/graphtoolkit/editor/graph.md)-derived class intended to function as a subgraph.

### Examples

```csharp
// This declares a subgraph type used by MyMainGraph
[Subgraph(typeof(MyMainGraph))]
public class MySubgraph : Graph
```