diff --git a/Example/Example/ViewController.swift b/Example/Example/ViewController.swift
index b399e90..74583d5 100644
--- a/Example/Example/ViewController.swift
+++ b/Example/Example/ViewController.swift
@@ -27,6 +27,9 @@ class ViewController: UIViewController {
     }
     
     var orderedDictionary: OrderedDictionary<String, Any> = .init()
+
+    private let notificationCenter = NotificationCenter.default
+    private var notificationObservations = [Any]()
     
     override func viewDidLoad() {
         super.viewDidLoad()
@@ -40,11 +43,14 @@ class ViewController: UIViewController {
         super.viewWillAppear(animated)
         
         title = appContainer.activeContainer?.name
+
+        registerNotifications()
     }
     
     override func viewDidDisappear(_ animated: Bool) {
         super.viewDidDisappear(animated)
         
+        unregisterNotifications()
     }
 
     private func setupViews() {
@@ -273,6 +279,26 @@ extension ViewController: UITableViewDelegate {
     }
 }
 
+extension ViewController {
+    func registerNotifications() {
+        let willChangeObservation = notificationCenter.addObserver(forName: AppContainer.containerWillChangeNotification, object: nil, queue: .current) { _ in
+            print("container will change")
+        }
+
+        let didChangeObservation = notificationCenter.addObserver(forName: AppContainer.containerWillChangeNotification, object: nil, queue: .current) { _ in
+            print("container did change")
+        }
+
+        self.notificationObservations = [willChangeObservation, didChangeObservation]
+    }
+
+    func unregisterNotifications() {
+        notificationObservations.forEach {
+            notificationCenter.removeObserver($0)
+        }
+    }
+}
+
 
 extension ViewController {
     class View: UIView {
diff --git a/Sources/AppContainer/AppContainer.swift b/Sources/AppContainer/AppContainer.swift
index 1393cc7..d616e61 100644
--- a/Sources/AppContainer/AppContainer.swift
+++ b/Sources/AppContainer/AppContainer.swift
@@ -8,6 +8,8 @@ public class AppContainer {
 
     private let fileManager = FileManager.default
 
+    private let notificationCenter = NotificationCenter.default
+
     /// home directory url
     private lazy var homeDirectoryUrl: URL = {
         URL(fileURLWithPath: NSHomeDirectory())
@@ -101,6 +103,8 @@ public class AppContainer {
             return
         }
 
+        notificationCenter.post(name: Self.containerWillChangeNotification, object: nil)
+
         try exportUserDefaults()
         exportCookies()
 
@@ -119,6 +123,8 @@ public class AppContainer {
         incrementActivatedCount(uuid: container.uuid)
         // update last activated date
         try? updateInfo(of: container, keyValue: .init(\.lastActivatedDate, Date()))
+
+        notificationCenter.post(name: Self.containerDidChangeNotification, object: nil)
     }
 
     /// activate selected container
diff --git a/Sources/AppContainer/Notification.swift b/Sources/AppContainer/Notification.swift
new file mode 100644
index 0000000..468c17f
--- /dev/null
+++ b/Sources/AppContainer/Notification.swift
@@ -0,0 +1,14 @@
+//
+//  AppContainer.Notification.swift
+//  
+//
+//  Created by p-x9 on 2023/02/27.
+//  
+//
+
+import Foundation
+
+extension AppContainer {
+    public static let containerWillChangeNotification = Notification.Name("com.p-x9.appcontainer.containerWillChange")
+    public static let containerDidChangeNotification = Notification.Name("com.p-x9.appcontainer.containerDidChange")
+}