After 6 years of Harpy and 4 years of Siren, I have decided to deprecate Harpy in favor of Siren. Why? Siren is written in Swift

Notify users when a new version of your app is available and prompt them to upgrade.
Under MIT License
By ArtSabintsev

objective-c carthage cocoapods alert update app-store

After 6 years of Harpy and 4 years of Siren, I have decided to deprecate Harpy in favor of Siren. Why? Siren is written in Swift and has a feature set that is superior to that of Harpy. More information can be found on this Medium post. The repository will live on, however, there will be no further updates and no transfers of the codebase at this time.

Notify users when a new version of your app is available and prompt them to upgrade.


Harpy checks a user's currently installed version of your iOS app against the version that is currently available in the App Store. If a new version is available, an alert can be presented to the user informing them of the newer version, and giving them the option to update the application.

Harpy is built to work with the Semantic Versioning system.
- Semantic Versioning is a three number versioning system (e.g., 1.0.0)
- Harpy also supports two-number versioning (e.g., 1.0)
- Harpy also supports four-number versioning (e.g.,
- Harpy only works with numbers.

Swift Support

Harpy was ported to Swift by myself and Aaron Brager. We've called the new project Siren.



Installation Instructions

pod 'Harpy'


github "ArtSabintsev/Harpy"


Copy the 'Harpy' folder into your Xcode project. It contains the Harpy.h and Harpy.m files.


  1. Import Harpy.h into your AppDelegate or Pre-Compiler Header (.pch)

  2. In your AppDelegate, optionally set the alertType.

  3. In your AppDelegate, call only one of the checkVersion methods, as all three perform a check on your application's first launch. Use either:

    • checkVersion in application:didFinishLaunchingWithOptions:

    • checkVersionDaily in applicationDidBecomeActive:.

    • checkVersionWeekly in applicationDidBecomeActive:.

``` obj-c
- (BOOL)application:(UIApplication )application didFinishLaunchingWithOptions:(NSDictionary )launchOptions {

// Present Window before calling Harpy
[self.window makeKeyAndVisible];

// Set the UIViewController that will present an instance of UIAlertController
[[Harpy sharedInstance] setPresentingViewController:_window.rootViewController];

// (Optional) Set the Delegate to track what a user clicked on, or to use a custom UI to present your message.
[[Harpy sharedInstance] setDelegate:self];

// (Optional) When this is set, the alert will only show up if the current version has already been released for X days.
// By default, this value is set to 1 (day) to avoid an issue where Apple updates the JSON faster than the app binary propogates to the App Store.
[[Harpy sharedInstance] setShowAlertAfterCurrentVersionHasBeenReleasedForDays:3];

// (Optional) The tintColor for the alertController
[[Harpy sharedInstance] setAlertControllerTintColor:@"<#alert_controller_tint_color#>"];

// (Optional) Set the App Name for your app
[[Harpy sharedInstance] setAppName:@"<#app_name#>"];

/* (Optional) Set the Alert Type for your app
By default, Harpy is configured to use HarpyAlertTypeOption */
[[Harpy sharedInstance] setAlertType:<#alert_type#>];

/* (Optional) If your application is not available in the U.S. App Store, you must specify the two-letter
country code for the region in which your applicaiton is available. */
[[Harpy sharedInstance] setCountryCode:@"<#country_code#>"];

/* (Optional) Overrides system language to predefined language.
Please use the HarpyLanguage constants defined in Harpy.h. */
[[Harpy sharedInstance] setForceLanguageLocalization:<#HarpyLanguageConstant#>];

/* (Optional): Delays the update prompt by a specific number of days. By default,
this value is set to 1 day to avoid an issue where Apple updates the JSON faster than the app binary propogates to the App Store.*/
[[Harpy sharedInstance] setShowAlertAfterCurrentVersionHasBeenReleasedForDays:<#Int#>];

// Perform check for new version of your app
[[Harpy sharedInstance] checkVersion];




And you're all set!

Differentiated Alerts for Patch, Minor, and Major Updates

If you would like to set a different type of alert for revision, patch, minor, and/or major updates, simply add one or all of the following optional lines to your setup before calling any of the checkVersion methods:

/* By default, Harpy is configured to use HarpyAlertTypeOption for all version updates */
[[Harpy sharedInstance] setPatchUpdateAlertType:<#alert_type#>];
[[Harpy sharedInstance] setMinorUpdateAlertType:<#alert_type#>];
[[Harpy sharedInstance] setMajorUpdateAlertType:<#alert_type#>];
[[Harpy sharedInstance] setRevisionUpdateAlertType:<#alert_type#>];

Optional Delegate and Delegate Methods

If you'd like to handle or track the end-user's behavior, four delegate methods have been made available to you:

``` obj-c
// User presented with update dialog
- (void)harpyDidShowUpdateDialog;

// User did click on button that launched App
- (void)harpyUserDidLaunchAppStore;

// User did click on button that skips version update
- (void)harpyUserDidSkipVersion;

// User did click on button that cancels update dialog
- (void)harpyUserDidCancel;


If you would like to use your own UI, please use the following delegate method to obtain the localized update message if a new version is available:

- (void)harpyDidDetectNewVersionWithoutAlert:(NSString *)message;


Harpy is localized for
- Arabic
- Armenian
- Basque
- Chinese (Simplified and Traditional)
- Croatian
- Czech
- Danish
- Dutch
- English
- Estonian
- Finnish
- French
- German
- Greek
- Hebrew
- Hungarian
- Indonesian
- Italian
- Japanese
- Korean
- Latvian
- Lithuanian
- Malay
- Norwegian (Bokmål)
- Persian (Iran, Afghanistan, Persian)
- Polish
- Portuguese (Brazil and Portugal)
- Russian
- Serbian (Cyrillic and Latin)
- Slovenian
- Spanish
- Swedish
- Thai
- Turkish
- Ukrainian
- Urdu
- Vietnamese

You may want the update dialog to always appear in a certain language, ignoring iOS's language setting (e.g. apps released in a specific country).

You can enable it like this:

[[Harpy sharedInstance] setForceLanguageLocalization<#HarpyLanguageConstant#>];

Device Compatibility

If an app update is available, Harpy checks to make sure that the version of iOS on the user's device is compatible the one that is required by the app update. For example, if a user has iOS 9 installed on their device, but the app update requires iOS 10, an alert will not be shown. This takes care of the false positive case regarding app updating.

Testing Harpy

Temporarily change the version string in Xcode (within the .xcodeproj) to an older version than the one that's currently available in the App Store. Afterwards, build and run your app, and you should see the alert.

If you currently don't have an app in the store, change your bundleID to one that is already in the store. In the sample app packaged with this library, we use the App Store Connect app's bundleID:

Important Note on App Store Submissions

The App Store reviewer will not see the alert.

Phased Releases

In 2017, Apple announced the ability to rollout app updates gradually (a.k.a. Phased Releases). Harpy will continue to work as it has in the past, presenting an update modal to all users. If you opt-in to a phased rollout for a specific version, you will need to remotely disable Harpy until the rollout is done.

Created and maintained by

Arthur Ariel Sabintsev