Render checkout in custom bottom sheet

Author: kiftio

README.md

@@ -29,7 +29,7 @@ This repository contains the Checkout Kit implementations, samples, and protocol
 | --- | --- | --- | --- | --- | --- |
 | `ShopifyCheckoutKit` | `4.0.0-alpha.2` | Swift Package Manager, CocoaPods | Alpha | iOS checkout presentation SDK. | [Swift](platforms/swift/README.md) |
 | `ShopifyAcceleratedCheckouts` | `4.0.0-alpha.2` | Swift Package Manager, CocoaPods subspec | Alpha | SwiftUI Shop Pay and Apple Pay accelerated checkout buttons for iOS 16+. | [Swift](platforms/swift/README.md#accelerated-checkouts) |
-| `com.shopify:checkout-kit` | `4.0.0-alpha.1` | Maven Central | Alpha | Android checkout dialog SDK. | [Android](platforms/android/README.md) |
+| `com.shopify:checkout-kit` | `4.0.0-alpha.2` | Maven Central | Alpha | Android checkout presentation SDK. | [Android](platforms/android/README.md) |
 | `@shopify/checkout-kit-react-native` | `4.0.0-alpha.2` | npm `next` dist-tag | Alpha | React Native wrapper for the iOS and Android native SDKs. | [React Native](platforms/react-native/README.md) |
 | `@shopify/checkout-kit` | `4.0.0-alpha.2` | npm `next` dist-tag | Alpha | Web component for opening Shopify checkout from a web page. | [Web](platforms/web/README.md) |
 | `ShopifyCheckoutProtocol` | Source package | Swift Package Manager | Internal/supporting | Swift client for Embedded Checkout Protocol messages. | [Protocol Swift](protocol/languages/swift/README.md) |
@@ -80,7 +80,7 @@ Use the Shopify.dev guides for broader product workflows:
 
 Checkout Kit is the current home for the SDKs that were previously published as Checkout Sheet Kit. The renamed packages use a shared `4.0.0-alpha.X` version format while the new package line settles:
 
-- Swift is currently `4.0.0-alpha.2`; Android and React Native start at `4.0.0-alpha.1`.
+- Swift, Android, and React Native are currently `4.0.0-alpha.2`.
 - Web is currently `4.0.0-alpha.2` and is published under the npm `next` dist-tag.
 - React Native requires React Native New Architecture.
 - Stable releases will continue on the same `4.x` package line after the alpha period.

platforms/android/AGENTS.md

@@ -8,7 +8,7 @@ Shopify Checkout Kit for Android publishes Maven artifacts that are consumed by
 
 The main modules are:
 
-- **`lib/`** — the Checkout Kit library, published as `com.shopify:checkout-kit`. It presents Shopify checkouts as a native, dialog-hosted WebView in consumer apps.
+- **`lib/`** — the Checkout Kit library, published as `com.shopify:checkout-kit`. It presents Shopify checkouts as a native bottom-sheet-hosted WebView in consumer apps.
 - **`../../protocol/languages/kotlin/embedded-checkout-protocol/`** — the Embedded Checkout Protocol Kotlin artifact, published as `com.shopify:embedded-checkout-protocol`. The Android Gradle project path is `:embedded-checkout-protocol`, and the Kotlin package is `com.shopify.ucp.embedded.checkout`.
 - **`samples/CheckoutKitAndroidDemo/`** — a demo app that consumes Checkout Kit and the Kotlin protocol artifact as source dependencies. Changes here never reach consumers; this module is for internal testing and developer onboarding.
 
@@ -25,7 +25,7 @@ The sample is a separate Gradle composite (`samples/CheckoutKitAndroidDemo/setti
 ## Key components
 
 - **`ShopifyCheckoutKit.kt`** — the public singleton. Entry point for all consumer interactions (configure, present).
-- **`CheckoutDialog.kt`** — the dialog that hosts the WebView, including the progress indicator and checkout error coordination.
+- **`CheckoutBottomSheet.kt`** — the bottom sheet that hosts the WebView, including the progress indicator, gesture coordination, and checkout error coordination.
 - **`CheckoutWebView.kt`** — primary WebView. Instruments page loads and attaches the ECP JavaScript interface.
 - **`BaseWebView.kt`** — abstract base class. Any new WebView variant must extend this so shared configuration (user agent suffix, WebChromeClient hooks, navigation error handling) is consistent.
 - **`CheckoutProtocol.kt`** — the curated consumer-facing Checkout Kit protocol API. This is where supported events/delegations are intentionally exposed.

platforms/android/README.md

@@ -10,7 +10,7 @@
 > production-ready. The current Checkout Kit for Android alpha is `4.0.0-alpha.2`.
 > Stability is not guaranteed, and breaking changes may occur in any release.
 
-**Checkout Kit for Android** lets Android apps present Shopify checkout in a native dialog while preserving store checkout customizations such as Checkout UI extensions, Shopify Functions, branding, and supported payment methods.
+**Checkout Kit for Android** lets Android apps present Shopify checkout in a native bottom sheet while preserving store checkout customizations such as Checkout UI extensions, Shopify Functions, branding, and supported payment methods.
 
 > [!NOTE]
 > This package was previously published as `com.shopify:checkout-sheet-kit`. New integrations should use `com.shopify:checkout-kit`.
@@ -114,14 +114,14 @@ val listener = object : DefaultCheckoutListener() {
 ShopifyCheckoutKit.present(checkoutUrl, activity, listener)
 ```
 
-The `present` call returns a `CheckoutKitDialog?`. Keep it if you need to dismiss the dialog programmatically:
+The `present` call returns a `CheckoutHandle?`. Keep it if you need to dismiss checkout programmatically:
 
 ```kotlin
-val checkoutDialog = ShopifyCheckoutKit.present(checkoutUrl, activity) {
+val checkout = ShopifyCheckoutKit.present(checkoutUrl, activity) {
     onCancel { resetCheckoutUi() }
 }
 
-checkoutDialog?.dismiss()
+checkout?.dismiss()
 ```
 
 ## Preload checkout
@@ -344,6 +344,10 @@ Checkout Kit opens external HTTPS links, `mailto:`, `tel:`, and custom-scheme li
 ## Troubleshooting
 
 - Use `LogLevel.DEBUG` while integrating.
+- For production release builds, use Android app shrinking and optimization
+  when appropriate. Checkout Kit does not require integration-specific R8 rules
+  for normal usage, and app-level shrinking can remove unused dependency code
+  and resources.
 - If checkout reports an expired, completed, or invalid cart, create a fresh cart and use its new `checkoutUrl`.
 - If checkout cannot access camera, file upload, or location features, check your manifest permissions and runtime permission flow.
 - If offsite payment redirects do not return to your app, verify App Links/deep link intent filters and domain association.

platforms/android/lib/api/lib.api

@@ -34,7 +34,7 @@ public final class com/shopify/checkoutkit/CheckoutExpiredException : com/shopif
 public final class com/shopify/checkoutkit/CheckoutExpiredException$Companion {
 }
 
-public abstract interface class com/shopify/checkoutkit/CheckoutKitDialog {
+public abstract interface class com/shopify/checkoutkit/CheckoutHandle {
 	public abstract fun dismiss ()V
 }
 
@@ -499,10 +499,10 @@ public final class com/shopify/checkoutkit/ShopifyCheckoutKit {
 	public static final fun getConfiguration ()Lcom/shopify/checkoutkit/Configuration;
 	public static final fun invalidate ()V
 	public static final fun preload (Ljava/lang/String;Landroidx/activity/ComponentActivity;)V
-	public static final fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;)Lcom/shopify/checkoutkit/CheckoutKitDialog;
-	public static final fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;Lcom/shopify/checkoutkit/CheckoutProtocol$Client;)Lcom/shopify/checkoutkit/CheckoutKitDialog;
-	public static final synthetic fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lkotlin/jvm/functions/Function1;)Lcom/shopify/checkoutkit/CheckoutKitDialog;
-	public static synthetic fun present$default (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;Lcom/shopify/checkoutkit/CheckoutProtocol$Client;ILjava/lang/Object;)Lcom/shopify/checkoutkit/CheckoutKitDialog;
+	public static final fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;)Lcom/shopify/checkoutkit/CheckoutHandle;
+	public static final fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;Lcom/shopify/checkoutkit/CheckoutProtocol$Client;)Lcom/shopify/checkoutkit/CheckoutHandle;
+	public static final synthetic fun present (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lkotlin/jvm/functions/Function1;)Lcom/shopify/checkoutkit/CheckoutHandle;
+	public static synthetic fun present$default (Ljava/lang/String;Landroidx/activity/ComponentActivity;Lcom/shopify/checkoutkit/DefaultCheckoutListener;Lcom/shopify/checkoutkit/CheckoutProtocol$Client;ILjava/lang/Object;)Lcom/shopify/checkoutkit/CheckoutHandle;
 }
 
 public final class com/shopify/checkoutkit/WindowOpenRequest {