# `GlyphsToolbarExtensionProvider`

*Protocol*

## Declaration

```swift
@MainActor protocol GlyphsToolbarExtensionProvider
```

```objc
@protocol GlyphsToolbarExtensionProvider
```

```python
GlyphsToolbarExtensionProvider
```

## Topics

### Instance Methods

- [`GlyphsToolbarExtensionProvider toolbarExtensionForWindow:`](/Core/GlyphsApp/GlyphsToolbarExtensionProvider/toolbarExtensionForWindow:) — Called before the toolbar is added to the window.