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Swift SDK for integrating Klaviyo’s push notifications, event tracking, and user profile management into iOS applications.

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klaviyo-swift-sdk

CI status Swift Package Manager SPM version Version License Minimum deployment version

Contents

Overview

The Klaviyo Swift SDK allows developers to incorporate Klaviyo's analytics and push notification functionality into their iOS applications. The SDK assists in identifying users and tracking events via Klaviyo Client APIs. To reduce performance overhead, API requests are queued and sent in batches. The queue is persisted to local storage so that data is not lost if the device is offline or the app is terminated.

Once integrated, your marketing team will be able to better understand your app users' needs and send them timely messages via APNs.

Installation

  1. Enable push notification capabilities in your Xcode project. The section "Enable the push notification capability" in this Apple developer guide provides detailed instructions.

  2. [Optional but recommended] If you intend to use rich push notifications add a Notification service extension to your xcode project. A notification service app extension ships as a separate bundle inside your iOS app. To add this extension to your app:

    • Select File > New > Target in Xcode.
    • Select the Notification Service Extension target from the iOS > Application extension section.
    • Click Next.
    • Specify a name and other configuration details for your app extension.
    • Click Finish.

    ⚠️ The deployment target of your notification service extension defaults to the latest iOS version. If this exceeds your app's minimum supported iOS version, push notifications may not display attached media on older devices. To avoid this, ensure the extension's minimum deployment target matches that of your app. ⚠️

  3. Based on which dependency manager you use, follow the instructions below to install the Klaviyo's dependencies.

    Swift Package Manager [Recommended]

    KlaviyoSwift is available via Swift Package Manager. Follow the steps below to install.

    1. Open your project and navigate to your project’s settings.
    2. Select the Package Dependencies tab and click on the add button below the packages list.
    3. Enter the URL of the Swift SDK repository https://github.com/klaviyo/klaviyo-swift-sdk in the text field. This should bring up the package on the screen.
    4. For the dependency rule dropdown select - Up to Next Major Version and leave the pre-filled versions as is.
    5. Click Add Package.
    6. On the next prompt, assign the package product KlaviyoSwift to your app target and KlaviyoSwiftExtension to the notification service extension target (if one was created) and click Add Package.
    CocoaPods

    KlaviyoSwift is available through CocoaPods.

    1. To install, add the following lines to your Podfile. Be sure to replace YourAppTarget and YourAppNotificationServiceExtenionTarget with the names of your app and notification service extension targets respectively.
    target 'YourAppTarget' do
      pod 'KlaviyoSwift'
    end
    
    target 'YourAppNotificationServiceExtenionTarget' do
      pod 'KlaviyoSwiftExtension'
    end
    1. Run pod install to complete the integration. The library can be kept up-to-date via pod update KlaviyoSwift and pod update KlaviyoSwiftExtension.
  4. Finally, in the NotificationService.swift file add the code for the two required delegates from this file. This sample covers calling into Klaviyo so that we can download and attach the media to the push notification.

Initialization

The SDK must be initialized with the short alphanumeric public API key for your Klaviyo account, also known as your Site ID.

// AppDelegate

import KlaviyoSwift

class AppDelegate: UIResponder, UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        KlaviyoSDK().initialize(with: "YOUR_KLAVIYO_PUBLIC_API_KEY")
        return true
    }
}

The SDK should be initialized before any other Klaviyo SDK methods are called.

Profile Identification

The SDK provides methods to identify your users as Klaviyo profiles via the Create Client Profile API. A profile can be identified by any combination of the following:

  • External ID: A unique identifier used by customers to associate Klaviyo profiles with profiles in an external system, such as a point-of-sale system. Format varies based on the external system.
  • Individual's email address
  • Individual's phone number in E.164 format

These above identifiers are persisted to local storage so that the SDK can keep track of the current user/profile for you when you make event requests or want to set a push token etc.

Profile identifiers can be set all at once or individually. Either way, the SDK will group and batch API calls to improve performance.

The following code demonstrates how to set profile identifiers:

// organization, title, image, location and additional properties (dictionary) can also be set using the below constructor
let profile = Profile(email: "junior@blob.com",  firstName: "Blob",  lastName: "Jr.")
KlaviyoSDK().set(profile: profile)

// or setting individual properties
KlaviyoSDK().set(profileAttribute: .firstName, value: "Blob")
KlaviyoSDK().set(profileAttribute: .lastName, value: "Jr.")

Reset Profile

To start a new profile altogether (e.g. if a user logs out) either call KlaviyoSDK().resetProfile() to clear the currently tracked profile identifiers, or use KlaviyoSDK().set(profile: profile) to overwrite it with a new profile object.

// start a profile for Blob Jr.
let profile = Profile(email: "junior@blob.com",  firstName: "Blob",  lastName: "Jr.")
KlaviyoSDK().set(profile: profile)

// stop tracking Blob Jr.
KlaviyoSDK().resetProfile()

// start a profile for Robin Hood
let profile = Profile(email: "robin@hood.com",  firstName: "Robin",  lastName: "Hood")
KlaviyoSDK().set(profile: profile)

Anonymous Tracking Notice

Klaviyo will track unidentified users with an autogenerated ID whenever a push token is set or an event is created. That way, you can collect push tokens and track events prior to collecting profile identifiers such as email or phone number. When an identifier is provided, Klaviyo will merge the anonymous user with an identified user.

Event tracking

The SDK provides tools for tracking events that users perform on your app via the Create Client Event API. Below is an example of how to track an event:

// using a predefined event name
let event = Event(name: .StartedCheckoutMetric,
                  properties: [
                        "name": "cool t-shirt",
                        "color": "blue",
                        "size": "medium",
                      ],
                  value: 166 )

KlaviyoSDK().create(event: event)

// using a custom event name
let customEvent = Event(name: .CustomEvent("Checkout Completed"),
                  properties: [
                        "name": "cool t-shirt",
                        "color": "blue",
                        "size": "medium",
                      ],
                  value: 166)

KlaviyoSDK().create(event: customEvent)

Arguments

The create method takes an event object as an argument. The event can be constructed with the following arguments:

  • [required] name: The name of the event you want to track, as a EventName enum. A list of common Klaviyo defined event metrics can be found in Event.EventName. You can also create custom events by using the CustomEvent enum case of Event.EventName
  • properties: A dictionary of properties that are specific to the event. This argument is optional.
  • value: A numeric value (Double) to associate with this event. For example, the dollar amount of a purchase.

Push Notifications

Prerequisites

Collecting Push Tokens

In order to send push notifications to your users, you must collect their push tokens and register them with Klaviyo. This is done via the KlaviyoSDK().set(pushToken:) method, which registers a push token and current authorization state via the Create Client Push Token API.

Below is the code to do both of the above steps:

import KlaviyoSwift

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    KlaviyoSDK().initialize(with: "YOUR_KLAVIYO_PUBLIC_API_KEY")

    UIApplication.shared.registerForRemoteNotifications()

    return true
}

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    KlaviyoSDK().set(pushToken: deviceToken)
}

Request Push Notification Permission

Once the push token is obtained, the next step is to request permission from your users to send them push notifications. You can add the permission request code anywhere in your application where it makes sense to prompt users for this permission. Apple provides some guidelines on the best practices for when and how to ask for this permission. The following example demonstrates how to request push permissions within the application:didFinishLaunchingWithOptions: method in the application delegate file. However, it's worth noting that this may not be the ideal location as it could interrupt the app's startup experience.

After setting a push token, the Klaviyo SDK will automatically track changes to the user's notification permission whenever the application is opened or resumed from the background.

Below is example code to request push notification permission:

import UserNotifications

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    KlaviyoSDK().initialize(with: "YOUR_KLAVIYO_PUBLIC_API_KEY")

    UIApplication.shared.registerForRemoteNotifications()

    let center = UNUserNotificationCenter.current()
	center.delegate = self as? UNUserNotificationCenterDelegate // the type casting can be removed once the delegate has been implemented
	let options: UNAuthorizationOptions = [.alert, .sound, .badge]
	// use the below options if you are interested in using provisional push notifications. Note that using this will not
	// show the push notifications prompt to the user.
	// let options: UNAuthorizationOptions = [.alert, .sound, .badge, .provisional]
	center.requestAuthorization(options: options) { granted, error in
	    if let error = error {
	        // Handle the error here.
	        print("error = ", error)
	    }

	    // Irrespective of the authorization status call `registerForRemoteNotifications` here so that
	    // the `didRegisterForRemoteNotificationsWithDeviceToken` delegate is called. Doing this
	    // will make sure that Klaviyo always has the latest push authorization status.
            DispatchQueue.main.async {
                UIApplication.shared.registerForRemoteNotifications()
            }
	}

    return true
}

Receiving Push Notifications

Tracking Open Events

When a user taps on a push notification, Implement userNotificationCenter:didReceive:withCompletionHandler and userNotificationCenter:willPresent:withCompletionHandler in your application delegate to handle receiving push notifications when the app is in the background and foreground respectively.

Below is an example of how to handle push notifications in your app delegate:

// be sure to set the UNUserNotificationCenterDelegate to self in the didFinishLaunchingWithOptions method (refer the requesting push notification permission section above for more details on this)
extension AppDelegate: UNUserNotificationCenterDelegate {
    // below method will be called when the user interacts with the push notification
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        didReceive response: UNNotificationResponse,
        withCompletionHandler completionHandler: @escaping () -> Void) {
        // If this notification is Klaviyo's notification we'll handle it
        // else pass it on to the next push notification service to which it may belong
        let handled = KlaviyoSDK().handle(notificationResponse: response, withCompletionHandler: completionHandler)
        if !handled {
            completionHandler()
        }
    }

    // below method is called when the app receives push notifications when the app is the foreground
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        if #available(iOS 14.0, *) {
            completionHandler([.list, .banner])
        } else {
            completionHandler([.alert])
        }
    }
}

When tracking opened push notification, you can also decrement the badge count on the app icon by adding the following code to the userNotificationCenter:didReceive:withCompletionHandler method:

    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        didReceive response: UNNotificationResponse,
        withCompletionHandler completionHandler: @escaping () -> Void) {
        // decrement the badge count on the app icon
        if #available(iOS 16.0, *) {
            UNUserNotificationCenter.current().setBadgeCount(UIApplication.shared.applicationIconBadgeNumber - 1)
        } else {
            UIApplication.shared.applicationIconBadgeNumber -= 1
        }

        // If this notification is Klaviyo's notification we'll handle it
        // else pass it on to the next push notification service to which it may belong
        let handled = KlaviyoSDK().handle(notificationResponse: response, withCompletionHandler: completionHandler)
        if !handled {
            completionHandler()
        }
    }

Additionally, if you just want to reset the badge count to zero when the app is opened(note that this could be from the user just opening the app independent of the push message), you can add the following code to the applicationDidBecomeActive method in the app delegate:

func applicationDidBecomeActive(_ application: UIApplication) {
    // reset the badge count on the app icon
    if #available(iOS 16.0, *) {
        UNUserNotificationCenter.current().setBadgeCount(0)
    } else {
        UIApplication.shared.applicationIconBadgeNumber = 0
    }
}

Once your first push notifications are sent and opened, you should start to see Opened Push metrics within your Klaviyo dashboard.

Deep Linking

ℹ️ Your app needs to use version 1.7.2 at a minimum in order for the below steps to work.

Deep Links allow you to navigate to a particular page within your app in response to the user opening a push notification.

You need to configure deep links in your app for them to work. The configuration process for Klaviyo is no different from what is required for handling deep linking in general, so you can follow the Apple documentation for deep linking in conjunction with the steps outlined here.

You have two options for implementing deep links: URL schemes and Universal Links.

Option 1: URL Schemes

URL schemes are the traditional and simpler way of deep linking from a push notification to your app. However, these links will only work if your mobile app is installed on a device and will not be understood by a web browser if, for example, you want to link from an email to your app.

Step 1: Register the URL scheme

In order for Apple to route a deep link to your application you need to register a URL scheme in your application's Info.plist file. This can be done using the editor that xcode provides from the Info tab of your project settings or by editing the Info.plist directly.

The required fields are as following:

  1. Identifier - The identifier you supply with your scheme distinguishes your app from others that declare support for the same scheme. To ensure uniqueness, specify a reverse DNS string that incorporates your company’s domain and app name. Although using a reverse DNS string is a best practice, it doesn’t prevent other apps from registering the same scheme and handling the associated links.
  2. URL schemes - In the URL Schemes box, specify the prefix you use for your URLs.
  3. Role - Since your app will be editing the role select the role as editor.

In order to edit the Info.plist directly, just fill in your app specific details and paste this in your plist.

<key>CFBundleURLTypes</key>
<array>
	<dict>
		<key>CFBundleTypeRole</key>
		<string>Editor</string>
		<key>CFBundleURLName</key>
		<string>{your_unique_identifier}</string>
		<key>CFBundleURLSchemes</key>
		<array>
			<string>{your_URL_scheme}</string>
		</array>
	</dict>
</array>
Step 2: Whitelist supported URL schemes

Since iOS 9 Apple has mandated that the URL schemes that your app can open need to also be listed in the Info.plist. This is in addition to Step 1 above. Even if your app isn't opening any other apps, you still need to list your app's URL scheme in order for deep linking to work.

This needs to be done in the Info.plist directly:

<key>LSApplicationQueriesSchemes</key>
<array>
	<string>{your custom URL scheme}</string>
</array>
Step 3: Implement handling deep links in your app

Steps 1 and 2 enable your app to receive deep links, but you also need to handle these links within your app. This is done by implementing the application:openURL:options: method in your app delegate.

Example:

func application(
    _ app: UIApplication,
    open url: URL,
    options: [UIApplication.OpenURLOptionsKey : Any] = [:]
) -> Bool {
    guard let components = NSURLComponents(url: url, resolvingAgainstBaseURL: true)
    else {
       print("Invalid deep linking URL")
       return false
    }

    print("components: \(components.debugDescription)")

    return true
}

If you are using SwiftUI, then you can implement onOpenURL(perform:) as a view modifier in the view you intent to handle deep links. This may or may not be the root of your scene.

Example:

@main
struct MyApplication: App {
  var body: some Scene {
    WindowGroup {
      ContentView()
        .onOpenURL { url in
          // handle the URL that must be opened
        }
    }
  }
}

Finally, we have an example app (Examples/KlaviyoSwiftExamples) in the SDK repo that you can reference to get an example of how to implement deep links in your app.

Once the above steps are complete, you can send push notifications from the Klaviyo Push editor within the Klaviyo website. Here you can build and send a push notification through Klaviyo to make sure that the URL shows up in the handler you implemented in Step 3.

Additionally, you can also locally trigger a deep link to make sure your code is working using the below command in the terminal.

xcrun simctl openurl booted {your_URL_here}

Option 2: Universal links

Universal links are a more modern way of handling deep links and are recommended by Apple. They are more secure and provide a better user experience. However, unlike URL schemes they require a bit more setup that is highlighted in these Apple docs.

Once you have the setup from the Apple docs in place you will need to modify the push open tracking as described below:

extension AppDelegate: UNUserNotificationCenterDelegate {
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        let handled = KlaviyoSDK().handle(notificationResponse: response, withCompletionHandler: completionHandler) { url in
            print("deep link is ", url)
        }
        if !handled {
           // not a klaviyo notification should be handled by other app code
        }
    }
}

Note that the deep link handler will be called back on the main thread. If you want to handle URL schemes in addition to universal links you implement them as described in Option 1: URL Schemes.

Rich Push

ℹ️ Rich push notifications are supported in SDK version 2.2.0 and higher

Rich Push is the ability to add images to push notification messages. Once the steps in the Installation section are complete, you should have a notification service extension in your project setup with the code from the KlaviyoSwiftExtension. Below are instructions on how to test rich push notifications.

Testing rich push notifications
  • To test rich push notifications, you will need three things:
  • A push notification payload that resembles what Klaviyo would send to you. The below payload should work as long as the image is valid:
{
  "aps": {
    "alert": {
      "title": "Free apple vision pro",
      "body": "Free Apple vision pro when you buy a Klaviyo subscription."
    },
    "mutable-content": 1
  },
  "rich-media": "https://www.apple.com/v/apple-vision-pro/a/images/overview/hero/portrait_base__bwsgtdddcl7m_large.jpg",
  "rich-media-type": "jpg"
}
  • A real device's push notification token. This can be printed out to the console from the didRegisterForRemoteNotificationsWithDeviceToken method in AppDelegate.

Once you have these three things, you can then use the push notifications tester and send a local push notification to make sure that everything was set up correctly.

Additional Details

Sandbox Support

ℹ️ Sandbox support is available in SDK version 2.2.0 and higher

Apple has two environments with push notification support - Production and Sandbox. The Production environment supports sending push notifications to real users when an app is published in the App Store or TestFlight. In contrast, Sandbox applications that support push notifications are those signed with iOS Development Certificates, instead of iOS Distribution Certificates. Sandbox acts as a staging environment, allowing you to test your applications in a environment similar to but distinct from Production without having to worry about sending messages to real users.

Our SDK supports the use of Sandbox for push as well. Klaviyo's SDK will determine and store the environment that your push token belongs to and communicate that to our backend, allowing your tokens to route sends to the correct environments. There is no additional setup needed. As long as you have deployed your application to Sandbox with our SDK employed to transmit push tokens to our backend, the ability to send and receive push on these Sandbox applications should work out-of-the-box.

SDK Data Transfer

Starting with version 1.7.0, the SDK will cache incoming data and flush it back to the Klaviyo API on an interval. The interval is based on the network link currently in use by the app. The table below shows the flush interval used for each type of connection:

Network Interval
WWAN/Wifi 10 seconds
Cellular 30 seconds

Connection determination is based on notifications from our reachability service. When there is no network available, the SDK will cache data until the network becomes available again. All data sent by the SDK should be available shortly after it is flushed by the SDK.

Retries

The SDK will retry API requests that fail under certain conditions. For example, if a network timeout occurs, the request will be retried on the next flush interval. In addition, if the SDK receives a rate limiting error 429 from the Klaviyo API, it will use exponential backoff with jitter to retry the next request.

Contributing

See the contributing guide to learn how to contribute to the Klaviyo Swift SDK. We welcome your feedback in the issues section of our public GitHub repository.

License

KlaviyoSwift is available under the MIT license. See the LICENSE file for more info.