---
title: Notification Keys
framework: assetslibrary
role: collectionGroup
role_heading: API Collection
path: assetslibrary/notification-keys
---

# Notification Keys

Keys used to get values from the user information dictionary of the ALAssetsLibraryChangedNotification notification.

## Overview

Overview Assets that are modified use the ALAssetLibraryUpdatedAssetsKey key. Assets that are inserted or deleted use the ALAssetLibraryUpdatedAssetGroupsKey key for the asset group that contains the asset. Assets and asset groups that have no strong references are omitted from the notification’s user information dictionary.

## See Also

### Constants

- [Types of Asset](assetslibrary/types-of-asset.md)
- [Error Domain](assetslibrary/error-domain.md)
- [Error Codes](assetslibrary/error-codes.md)