# `GSKeyValueObservation`

*Class*

A reimplementation of Swift’s `NSKeyValueObservation`, usable from Objective-C and using string key paths.

## Declaration

```swift
class GSKeyValueObservation
```

```objc
@interface GSKeyValueObservation : NSObject
```

```python
class GSKeyValueObservation(NSObject)
```

## Topics

### Type Methods

- [`GSKeyValueObservation observe:forKeyPath:withObserver:options:context:`](/Core/GlyphsCore/GSKeyValueObservation/observe:forKeyPath:withObserver:options:context:) — Creates a new observation proxy that observes the given object, forwarding observation messages to the given observer.
- [`GSKeyValueObservation replaceObservation:observe:forKeyPath:withObserver:options:context:`](/Core/GlyphsCore/GSKeyValueObservation/replaceObservation:observe:forKeyPath:withObserver:options:context:) — Replaces an existing observation with a new observation.

## Relationships

### Inherits From

- `NSObject`