# OnGraphChanged(GraphLogger)

> Called after the graph has changed.

## Definition

* **Type:** Method
* **Namespace:** [Unity.GraphToolkit.Editor](/engine/6000.6/script-reference/unity/graphtoolkit/editor.md)
* **Assembly:** UnityEditor

```csharp
public virtual void OnGraphChanged(GraphLogger graphLogger)
```

### Parameters

**** (\[GraphLogger]\(/engine/6000.6/script-reference/unity/graphtoolkit/editor/graphlogger)): The [GraphLogger](/engine/6000.6/script-reference/unity/graphtoolkit/editor/graphlogger.md) that receives any errors or warnings related to the graph.

### Remarks

Unity calls this method after any change to the graph. Override it to validate the graph's integrity and report issues using the provided [GraphLogger](/engine/6000.6/script-reference/unity/graphtoolkit/editor/graphlogger.md). Use this method to detect invalid configurations, highlight issues in the editor, or provide user feedback. Do not modify the graph within this method, as it may cause instability or recursive updates.