---
title: "Migrate Adapty Flutter SDK to v4.1"
description: "Migrate to Adapty Flutter SDK v4.1: enable Adapty Attribution explicitly, adopt the renamed external attribution APIs, re-download your fallback file, and handle App Store promoted purchases."
---

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Adapty Flutter SDK 4.1 changes how Adapty Attribution is enabled, renames the external attribution APIs, and changes the fallback file format. It also hands App Store promoted in-app purchases to your app, and adds a way to keep a flow view alive after dismissing it.

:::warning
The renamed APIs are a hard break. The old names are removed outright — there are no deprecated aliases to bridge them. Code that compiles against 4.0.x fails on 4.1 until you rename every call site listed below.
:::

If you're still on 3.x, start with [Migrate to v4.0](migration-to-flutter-sdk-v4) and then follow this guide.

## Quick reference

| v4.0 | v4.1 |
|---|---|
| Adapty Attribution enabled automatically | Adapty Attribution disabled by default; opt in with `withAdaptyAttributionEnabled(true)` |
| `Adapty().updateAttribution(attribution, source: source)` | `Adapty().updateExternalAttribution(attribution, provider: provider)` |
| `AdaptyAttributionSource` | `AdaptyExternalAttributionProvider`, with a new `custom` value |
| `AdaptyProfile.appliedAttributionSources` | `AdaptyProfile.appliedExternalAttributionProviders` |
| Fallback file downloaded for 4.0 | New fallback file format; download the file again |
| Promoted in-app purchases completed on their own | Your app completes them from `didReceivePromotedPurchaseStream` |
| `dismissFlowView(view)` always releases the view | `destroy: false` keeps the view alive to present it again |

The purchase, profile, and flow-presentation APIs are otherwise unchanged.

## Installation

Update `adapty_flutter` to v4.1 in your `pubspec.yaml`:

```yaml showLineNumbers title="pubspec.yaml"
dependencies:
  adapty_flutter: 4.1.0
```

If your app uses [Kids Mode](kids-mode-flutter), specify `adapty_flutter_kids` instead:

```yaml showLineNumbers title="pubspec.yaml"
dependencies:
  adapty_flutter_kids: 4.1.0
```

The requirements are unchanged from 4.0: **Flutter 3.32.0** (Dart 3.8.0) and **iOS 15.0**. See [Install Adapty SDK](sdk-installation-flutter) for the full setup.

4.1 pins the native iOS SDK to 4.1.3 and the native Android SDK to 4.1.1. The iOS release also fixes numeric parameters of flow analytic events: before it, every `0` and `1` reached `flowViewDidReceiveAnalyticEvent` as `false` and `true`.

## ⚠️ Adapty Attribution is disabled by default \{#adapty-attribution-is-disabled-by-default\}

:::warning
If you update to SDK 4.1 and don't opt in, [Adapty Attribution](user-acquisition) breaks silently — installs stop registering, and nothing warns you.
:::

In 4.0 and earlier, the SDK registered installs for [Adapty Attribution](user-acquisition) automatically. Starting from 4.1, this is off by default: the SDK doesn't register installs, `onUpdateInstallationDetailsSuccessStream` and `onUpdateInstallationDetailsFailStream` never emit, and `getCurrentInstallationStatus` returns `AdaptyInstallationStatusNotAvailable`.

If you use Adapty Attribution, enable it when configuring the SDK:

```diff showLineNumbers
  await Adapty().activate(
-   configuration: AdaptyConfiguration(apiKey: 'YOUR_PUBLIC_SDK_KEY'),
+   configuration: AdaptyConfiguration(apiKey: 'YOUR_PUBLIC_SDK_KEY')
+     ..withAdaptyAttributionEnabled(true),
  );
```

If you don't use Adapty Attribution, no changes are needed.

## Renamed external attribution APIs

The APIs that pass attribution data from an external provider (Adjust, AppsFlyer, Branch, Tenjin, or a custom one) are renamed to match the native SDKs.

### updateAttribution → updateExternalAttribution

The method is renamed and its `source` parameter is renamed to `provider`. The parameter now takes an `AdaptyExternalAttributionProvider` instead of a string, and attribution data is still a map:

```diff showLineNumbers
- await Adapty().updateAttribution(attribution, source: 'adjust');
+ await Adapty().updateExternalAttribution(attribution, provider: AdaptyExternalAttributionProvider.adjust);
```

### AdaptyAttributionSource → AdaptyExternalAttributionProvider

The provider type is renamed. It stays an open wrapper over a string — the predefined values are `appleAds`, `adjust`, `appsflyer`, `branch`, `tenjin`, and a new `custom` for providers Adapty doesn't integrate with directly. You can construct one from any other string, so a provider Adapty adds later works without an SDK update:

```dart showLineNumbers
final provider = AdaptyExternalAttributionProvider('my_provider');
```

### AdaptyProfile.appliedAttributionSources → appliedExternalAttributionProviders

The profile property that lists the attribution providers applied to the profile is renamed, and its element type changes accordingly:

```diff showLineNumbers
- if (profile.appliedAttributionSources.contains(AdaptyAttributionSource.appleAds)) {
+ if (profile.appliedExternalAttributionProviders.contains(AdaptyExternalAttributionProvider.appleAds)) {
      // Apple Ads attribution has been applied
  }
```

The serialized profile field keeps the name `applied_attribution_sources`, so a backend that reads the raw profile needs no changes. Code that reads the property does — see [Show an Apple Ads targeted paywall](flutter-show-aa-targeted-paywall).

## Fallback files

The [fallback file](fallback-flows) format changed in SDK 4.1. Download the file again from **[Placements](https://app.adapty.io/placements)** > **Fallbacks** and bundle it in your app, even if you already downloaded one for 4.0.

:::warning
This step produces no build error. If you skip it, the SDK rejects the outdated file and every placement loses its fallback.
:::

## ⚠️ Promoted in-app purchases now wait for your app \{#promoted-in-app-purchases-now-wait-for-your-app\}

:::warning
This is a behavior change, not a new feature to adopt when convenient. On 4.0, an [in-app purchase promoted on your App Store product page](flutter-making-purchases#promoted-in-app-purchases-from-the-app-store) completed on its own. On 4.1, it completes only if your app listens for it. Ship 4.1 without the code below and those purchases stop happening — the App Store hands the product to your app, and nothing else occurs.
:::

On 4.0, Adapty recorded a promoted purchase like any other transaction, and your app had no way to intercept it. 4.1 gives your app that control, and with it the responsibility to finish the purchase.

Subscribe to `didReceivePromotedPurchaseStream` and pass the product to `makePromotedPurchase`:

```dart showLineNumbers
Adapty().didReceivePromotedPurchaseStream.listen((product) async {
  try {
    final result = await Adapty().makePromotedPurchase(product: product);
    // process the purchase result
  } on AdaptyError catch (e) {
    // handle the error
  }
});
```

Subscribe before a promoted purchase can arrive — during app startup, right after `activate`. The stream is a broadcast stream that doesn't replay: a product delivered while nothing is listening is dropped, and the purchase is lost with it.

`makePromotedPurchase` takes no purchase parameters, because a promoted product comes from the App Store rather than a paywall and carries no paywall context. It returns the same `AdaptyPurchaseResult` as `makePurchase`.

:::warning
The stream is built on StoreKit 2 and requires **iOS 16.4** or later. Below iOS 16.4, and on Android, it never emits.
:::

If the promoted product carries a subscription offer, the SDK applies it at purchase automatically. The offer is read from the App Store purchase intent, which exposes it on iOS 18.0 and later. On iOS 16.4–17.x, the purchase goes through at the base price.

## Keep a flow view alive after dismissing it

`AdaptyUI().dismissFlowView` and `AdaptyUIFlowView.dismiss` accept a `destroy` flag:

```dart showLineNumbers
await AdaptyUI().dismissFlowView(view, destroy: false);
```

It defaults to `true`, which releases the view as before. With `destroy: false` the view stays alive, so you can present it again and the user returns to the screen they left, with the state the flow had built up.

A view kept this way is held until you dismiss it with `destroy: true`. Presenting a released view fails, so call `createFlowView` again to show that flow once more.

## hasViewConfiguration

`AdaptyFlow.hasViewConfiguration` now also requires the flow to carry a UI schema, so it reports `true` only for a flow AdaptyUI can render. A flow that reached your app without its schema now reports `false` where 4.0 reported `true`. See [Fetch the view configuration](flutter-get-pb-paywalls#fetch-the-view-configuration).