Enable purchases with Flow Builder in Kotlin Multiplatform SDK

This guide uses Adapty Kotlin Multiplatform SDK v4 (beta) APIs. If you’re on v3, see the migration guide for the corresponding method names.

To enable in-app purchases, you need to understand three key concepts:

• Products – anything users can buy (subscriptions, consumables, lifetime access)
• Flows – screen sequences that present products to users, built in the no-code Flow Builder. The SDK retrieves them via getFlow. If you’d rather build the UI in your own code, use a paywall instead — see Implement paywalls manually.
• Placements – where and when you show flows in your app (like main, onboarding, settings). You attach flows to placements in the dashboard, then request them by placement ID in your code. This makes it easy to run A/B tests and show different flows to different users.

Adapty offers you three ways to enable purchases in your app. Select one of them depending on your app requirements:

To display a flow created in the Adapty Flow Builder, in your app code, you only need to:

1. Get the flow: Get it from Adapty.
2. Display it and Adapty will handle purchases for you: Show the view in your app.
3. Handle button actions: Associate user interactions with your app’s response to them. For example, open links or close the flow when users click buttons.

Before you start

Before you start, complete these steps:

1. Connect your app to the App Store and/or Google Play in the Adapty Dashboard.
2. Create your products in Adapty.
3. Create a flow and add products to it.
4. Create a placement and add your flow to it.
5. Install and activate the Adapty SDK in your app code.

1. Get the flow

Your flows are associated with placements configured in the dashboard. Placements allow you to run different flows for different audiences or to run A/B tests.

To get a flow created in the Adapty Flow Builder, you need to:

1. Get the flow object by the placement ID using the getFlow method.

2. Create the flow view using the createFlowView method. The view contains the UI elements and styling needed to display the flow. If the flow has no view configured, createFlowView returns an error — handle it in onError.

Adapty.getFlow("YOUR_PLACEMENT_ID")
    .onSuccess { flow ->
        AdaptyUI.createFlowView(flow)
            .onSuccess { view ->
                view.present()
            }
            .onError { error ->
                // the flow has no view configured, or view creation failed
            }
    }
    .onError { error ->
        // handle the error
    }

2. Display the flow

Now, when you have the flow, it’s enough to add a few lines to display it.

In order to display the visual flow on the device screen, you must first create the view. To do this, call the method AdaptyUI.createFlowView():

AdaptyUI.createFlowView(flow)
    .onSuccess { view ->
        view.present()
    }
    .onError { error ->
        // handle the error
    }

After the view has been successfully created, you can present it on the screen of the device. Each view can only be used once: after you call dismiss(), call createFlowView again to display the flow one more time.

3. Handle button actions

When users click buttons in the flow, the Kotlin Multiplatform SDK automatically handles purchases, restoration, closing the flow, and opening links.

However, other buttons have custom or pre-defined IDs and require handling actions in your code. Or, you may want to override their default behavior.

For example, here is the default behavior for the close button. You don’t need to add it in the code, but here, you can see how it is done if needed.

Note that, by default, the flow stays open after a successful purchase. If you want to close it once the purchase finishes, dismiss the view in the flowViewDidFinishPurchase callback.

AdaptyUI.setFlowsEventsObserver(object : AdaptyUIFlowsEventsObserver {
    override fun flowViewDidPerformAction(view: AdaptyUIFlowView, action: AdaptyUIAction) {
        when (action) {
            is AdaptyUIAction.CloseAction -> mainUiScope.launch { view.dismiss() }
            else -> Unit
        }
    }

    override fun flowViewDidFinishPurchase(
        view: AdaptyUIFlowView,
        product: AdaptyPaywallProduct,
        purchaseResult: AdaptyPurchaseResult
    ) {
        if (purchaseResult !is AdaptyPurchaseResult.UserCanceled) {
            mainUiScope.launch { view.dismiss() }
        }
    }
})

Next steps

Your flow is ready to be displayed in the app. Test your purchases in the App Store sandbox or in Google Play Store to make sure you can complete a test purchase from the flow.

Now, you need to check the users’ access level to ensure you display a flow or give access to paid features to right users.

Full example

Here is how all those steps can be integrated in your app together.

// Set up the observer for handling flow events
AdaptyUI.setFlowsEventsObserver(object : AdaptyUIFlowsEventsObserver {
    override fun flowViewDidPerformAction(view: AdaptyUIFlowView, action: AdaptyUIAction) {
        when (action) {
            is AdaptyUIAction.CloseAction -> mainUiScope.launch { view.dismiss() }
            else -> Unit
        }
    }

    override fun flowViewDidFinishPurchase(
        view: AdaptyUIFlowView,
        product: AdaptyPaywallProduct,
        purchaseResult: AdaptyPurchaseResult
    ) {
        if (purchaseResult !is AdaptyPurchaseResult.UserCanceled) {
            mainUiScope.launch { view.dismiss() }
        }
    }
})

// Get and display the flow
Adapty.getFlow("YOUR_PLACEMENT_ID")
    .onSuccess { flow ->
        AdaptyUI.createFlowView(flow)
            .onSuccess { view ->
                view.present()
            }
            .onError { error ->
                // the flow has no view configured — use custom logic
            }
    }
    .onError { error ->
        // handle the error
    }