# Node.IOptionDefinitionContext

> Interface that provides methods to declare node options inside a node.

## Definition

* **Type:** Interface
* **Namespace:** [Unity.GraphToolkit.Editor](/engine/6000.7/script-reference/unity/graphtoolkit/editor.md)
* **Assembly:** UnityEditor

```csharp
public interface Node.IOptionDefinitionContext
```

## Remarks

Use to add node options on nodes. Node options appear under the node header and in the inspector when a node is selected. They are appropriate for parameters that affect how a node behaves or changes its topology, such as modifying the number of ports.

## Methods

| Method                                                                                                            | Description             |
| ----------------------------------------------------------------------------------------------------------------- | ----------------------- |
| [AddOption](/engine/6000.7/script-reference/unity/graphtoolkit/editor/node/ioptiondefinitioncontext/addoption.md) | Adds a new node option. |