---
title: "React Native PDF annotation events & notifications | Nutrient React Native SDK"
canonical_url: "https://www.nutrient.io/guides/react-native/events-and-notifications/annotation/"
md_url: "https://www.nutrient.io/guides/react-native/events-and-notifications/annotation.md"
last_updated: "2026-05-18T12:22:04.662Z"
description: "Discover how to effectively manage annotations in React Native, improving your app's functionality and user experience with our expert tips and techniques."
---

# Annotation events and notifications

Nutrient React Native SDK lets you detect when one or more annotations have changed via the `AnnotationEvent` event listeners. Here’s how to register for the event listeners to be notified when one or more annotations have changed:

```js

override componentDidMount() {
    this.pdfRef.current?.getNotificationCenter().subscribe(NotificationCenter.AnnotationsEvent.CHANGED, (event: any) => {
      Alert.alert('Nutrient', JSON.stringify(event));
    });

    this.pdfRef.current?.getNotificationCenter().subscribe(NotificationCenter.AnnotationsEvent.ADDED, (event: any) => {
      Alert.alert('Nutrient', JSON.stringify(event));
    });

    this.pdfRef.current?.getNotificationCenter().subscribe(NotificationCenter.AnnotationsEvent.REMOVED, (event: any) => {
      Alert.alert('Nutrient', JSON.stringify(event));
    });
  }

```

When done, remember to unregister from the event listeners:

```js

override componentWillUnmount () {
	this.pdfRef.current?.getNotificationCenter().unsubscribe(NotificationCenter.AnnotationsEvent.CHANGED);
	this.pdfRef.current?.getNotificationCenter().unsubscribe(NotificationCenter.AnnotationsEvent.ADDED);
	this.pdfRef.current?.getNotificationCenter().unsubscribe(NotificationCenter.AnnotationsEvent.REMOVED);
}

```

---

## Related pages

- [Analytics events](/guides/react-native/events-and-notifications/analytics.md)
- [PDF form events and notifications](/guides/react-native/events-and-notifications/forms.md)
- [PDF viewer events](/guides/react-native/events-and-notifications/events.md)
- [Events and notifications](/guides/react-native/events-and-notifications.md)
- [Viewer events](/guides/react-native/events-and-notifications/viewer.md)