# `GSFont.undoManager`

*Instance Property*

The undo manager used for font-level changes, or `nil` when no document provides one.

## Declaration

```swift
var undoManager: UndoManager? { get }
```

```objc
@property (nonatomic, readonly) NSUndoManager * undoManager;
```

```python
undoManager() -> NSUndoManager
```

## Discussion

Glyphs keep their own undo managers. Use [`GSFont disableUndo`](/Core/GlyphsCore/GSFont/disableUndo) and [`GSFont enableUndo`](/Core/GlyphsCore/GSFont/enableUndo) when undo registration must be changed for the font and all glyphs.

## See Also

### Undo

- [`GSFont disableUndo`](/Core/GlyphsCore/GSFont/disableUndo) — Disables undo registration for the font and its glyphs.
- [`GSFont enableUndo`](/Core/GlyphsCore/GSFont/enableUndo) — Enables undo registration for the font and its glyphs.