web2wave deferred deeplinks

After a user completes a web2wave quiz or paywall in the browser and installs your app, you need their web2wave user_id inside the native app to unlock the subscription.

Most teams get that user_id through a mobile measurement partner (MMP) — AppsFlyer, Adjust, Branch, and similar tools pass it via an install deeplink. That works well if you already run an MMP stack.

If you do not use an MMP, web2wave provides deferred deeplinks as a built-in alternative. Every Mobile SDK sends device-matching headers on API requests and exposes an identify() method (GET /api/user/identify) that matches the installed device against recent web sessions on your project and returns the user_id.

No third-party attribution SDK required.

MMP vs web2wave deferred deeplinks

	MMP (AppsFlyer, Adjust, Branch, …)	web2wave deferred deeplinks
Extra SDK	Yes — MMP SDK in the app	No — built into web2wave SDK
How `user_id` arrives	Install / deferred deeplink from MMP	`identify()` on first app open
Setup	MMP dashboard + deeplink in project settings	Initialize web2wave SDK + call `identify()`
Best for	Teams already using MMP for ads & attribution	Simpler stacks, no MMP budget, web-to-app only

📘
These approaches are alternatives, not layers. Pick one attribution path for resolving user_id on install. If you already use AppsFlyer or Adjust, follow the RevenueCat, Adapty, or direct API guides with your MMP deeplink handler.

You can also use web2wave's custom deeplink page without an MMP — but that still requires the user to open the install link again after downloading the app. Deferred deeplinks remove that extra step.

When to use deferred deeplinks

Scenario	Recommended approach
You use AppsFlyer, Adjust, Branch, etc.	MMP deeplink — see integration guides above
You want web-to-app attribution without an MMP	Call `identify()` on first app launch
User already known in app (stored `user_id`)	Skip attribution; use stored value

Call identify() once per fresh install, typically on first app open and before linking Adapty / RevenueCat / Qonversion profiles.

How deferred deeplinks work

The SDK automatically attaches these HTTP headers to every API call (including identify()):

Header	Example	Purpose
`platform`	`iOS`, `Android`	Device family
`screen_size`	`390x844`	Logical screen resolution
`timezone`	`UTC+03:00`	Local timezone offset
`os_version`	`iOS 18.0`, `Android 14`	OS version string
`api-key`	your project key	Project authentication

The identify() endpoint compares this device context against web sessions collected during quiz/paywall visits on the same project.

Response format

A successful match returns:

{
  "success": 1,
  "user_id": "identified_user_guid",
  "match_method": "match_method_used",
  "platform": "iOS"
}

If no match is found, success is not 1 or the call returns null / invokes the error callback depending on the SDK.

Integration flow

After you have a user_id, link your paywall SDK and verify entitlement:

setAdaptyProfileID / setRevenuecatProfileID / setQonversionProfileID
Wait 1–2 seconds, then restore purchases in the subscription SDK
hasActiveSubscription(user_id) to unlock content

Code examples

   Web2Wave.shared.initialize(apiKey: 'your-api-key');

   // No MMP — resolve user_id via deferred deeplink
   final identificationData = await Web2Wave.shared.identify();

   if (identificationData != null && identificationData['success'] == 1) {
     final userId = identificationData['user_id'] as String?;
     if (userId != null) {
       await Web2Wave.shared.setAdaptyProfileID(
         web2waveUserId: userId,
         adaptyProfileId: adaptyProfile.profileId!,
       );
       await Future.delayed(const Duration(seconds: 2));
       await Adapty().restorePurchases();
     }
   }

💡
Run network calls off the main thread on Android (Java/Kotlin). Use a background coroutine with Dispatchers.IO or an ExecutorService.

Direct API usage

If you are not using an SDK, send the same headers manually:

curl -X GET "https://api.web2wave.com/api/user/identify" \
  -H "api-key: YOUR_API_KEY" \
  -H "platform: iOS" \
  -H "screen_size: 390x844" \
  -H "timezone: UTC+03:00" \
  -H "os_version: iOS 18.0"

MMP vs web2wave deferred deeplinks

When to use deferred deeplinks

How deferred deeplinks work

Response format

Integration flow

Code examples

Direct API usage

Related guides