Unified Deep Linking (UDL)

At a glance: Unified deep linking (UDL) enables you to send new and existing users to a specific in-app activity (for example, a specific page in the app) as soon as the app is opened.


UDL privacy protection

For new users, the UDL method only returns parameters relevant to deferred deep linking: deep_link_value and deep_link_sub1-10. If you try to get any other parameters (media_source, campaign, af_sub1-5, etc.), they return null.


UDL routes mobile users into a specific activity or content in an app.

The flow works as follows:

  1. User clicks a OneLink link.
    • If the user has the app installed, the Android App Links or URI scheme opens the app.
    • If the user doesn't have the app installed, they are redirected to the app store, and after downloading, the user opens the app.
  2. The app open triggers the AppsFlyer SDK.
  3. The AppsFlyer SDK runs the UDL API.
  4. The UDL API retrieves OneLink data from AppsFlyer servers.
  5. The UDL API calls back the onDeepLinking() method in the DeepLinkingListener class.
  6. The onDeepLinking() method gets a DeepLinkResult object.
  7. The DeepLinkResult object includes:
    • Status (Found/Not found/Error)
    • A DeepLink object that carries the deep_link_value and deep_link_sub1-10 parameters, that the developer uses to route the user to a specific in-app activity, which is the main goal of OneLink.


  • UDL requires AppsFlyer Android SDK V6.1+.


When setting up OneLinks, the marketer uses parameters to create the links, and the developer customizes the behavior of the app based on the values received. It is the developer's responsibility to make sure the parameters are handled correctly in the app, for both in-app routing, and personalizing data in the link.

To plan the OneLink:

  1. Get from the marketer the desired behavior and personal experience a user gets when they click the URL.
  2. Based on the desired behavior, plan the deep_link_value and other parameters that are needed to give the user the desired personal experience.
    • The deep_link_value is set by the marketer in the URL and used by the developer to redirect the user to a specific place inside the app. For example, if you have a fruit store and want to direct users to apples, the value of deep_link_value can be apples.
    • The deep_link_sub1-10 parameters can also be added to the URL to help personalize the user experience. For example, to give a 10% discount, the value of deep_link_sub1 can be 10.


Implement the UDL API logic based on the chosen parameters and values.

  1. Use the subscribeForDeepLink() method (from AppsFlyerLib) to register the DeepLinkListener interface listener.
  2. Make sure you override the callback function onDeepLinking().
    onDeepLinking() accepts as an argument a DeepLinkResult object.
  3. Use getStatus() to query whether the deep linking match is found.
  4. For when the status is an error, call getError() and run your error flow.
  5. For when the status is found, use getDeepLink() to retrieve the DeepLink object.
    The DeepLink object contains the deep linking information and helper functions to easily retrieve values from well-known OneLink keys, for example, getDeepLinkValue().
  6. Use getDeepLinkValue() to retrieve the deep_link_value.
  7. Use getStringValue("deep_link_sub1") to retrieve deep_link_sub1. Do the same for deep_link_sub2-10 parameters, changing the string value as required.
  8. Once deep_link_value and deep_link_sub1-10 are retrieved, pass them to an in-app router and use them to personalize the user experience.

Code example

appsflyer.subscribeForDeepLink(new DeepLinkListener(){
            public void onDeepLinking(@NonNull DeepLinkResult deepLinkResult) {
                DeepLinkResult.Status dlStatus = deepLinkResult.getStatus();
                if (dlStatus == DeepLinkResult.Status.FOUND) {
                    Log.d(LOG_TAG, "Deep link found");
                } else if (dlStatus == DeepLinkResult.Status.NOT_FOUND) {
                    Log.d(LOG_TAG, "Deep link not found");
                } else {
                    // dlStatus == DeepLinkResult.Status.ERROR
                    DeepLinkResult.Error dlError = deepLinkResult.getError();
                    Log.d(LOG_TAG, "There was an error getting Deep Link data: " + dlError.toString());
                DeepLink deepLinkObj = deepLinkResult.getDeepLink();
                try {
                    Log.d(LOG_TAG, "The DeepLink data is: " + deepLinkObj.toString());
                } catch (Exception e) {
                    Log.d(LOG_TAG, "DeepLink data came back null");
                // An example for using is_deferred
                if (deepLinkObj.isDeferred()) {
                    Log.d(LOG_TAG, "This is a deferred deep link");
                } else {
                    Log.d(LOG_TAG, "This is a direct deep link");
                // ** Next if statement is optional **
                // Our sample app's user-invite carries the referrerID in deep_link_sub2
                // See the user-invite section in FruitActivity.java
                if (dlData.has("deep_link_sub2")){
                    referrerId = deepLinkObj.getStringValue("deep_link_sub2");
                    Log.d(LOG_TAG, "The referrerID is: " + referrerId);
                } else {
                    Log.d(LOG_TAG, "deep_link_sub2/Referrer ID not found");
                // An example for using a generic getter
                String fruitName = "";
                try {
                    fruitName = deepLinkObj.getDeepLinkValue();
                    Log.d(LOG_TAG, "The DeepLink will route to: " + fruitName);
                } catch (Exception e) {
                    Log.d(LOG_TAG, "Custom param fruit_name was not found in DeepLink data");
                goToFruit(fruitName, deepLinkObj);

⇲ Github links: Java

Did this page help you?