skiptools · dfabulich · May 8, 2026
diff --git a/README.md b/README.md
@@ -3090,6 +3090,91 @@ struct CityPickerView: View {
 }
 ```
 
+#### Configure navigation transition animations
+
+SkipUI uses [Navigation 3](https://developer.android.com/guide/navigation/navigation-3) transition animations to animate pushing/popping in  `NavigationStack` and to animate switching tabs in `TabView`. For `TabView`, we use Navigation 3's default animation (a quick fade), and for `NavigationStack`, we simulate SwiftUI's default animation with a slide + fade animation.
+
+You can configure these navigation animations with the `.navigationStackTransitions` and `.tabViewTransitions` modifiers. You pass it a closure that returns a `NavDisplayTransitionOptions` object.
+
+```swift
+public struct NavDisplayTransitionOptions {
+    public enum TransitionPreset {
+        case `default` // `default` uses NavDisplay.defaultTransitionSpec, .defaultPopTransitionSpec, and .defaultPredictivePopTransitionSpec
+        case slide
+        case fade
+        case slideAndFade // This is the default NavigationStack transition
+        case none // instant transition with no animation
+    }
+
+    public init(_ transitionPresets: TransitionPreset)
+
+    public func copy(
+        transition: TransitionPreset? = nil,
+        popTransition: TransitionPreset? = nil,
+        predictivePopTransition: TransitionPreset? = nil
+    ) -> NavDisplayTransitionOptions
+
+    #if SKIP
+    public let transitionSpec: ContentTransform?
+    public let popTransitionSpec: ContentTransform?
+    public let predictivePopTransitionSpec: ContentTransform?
+
+    public init(
+        transitionSpec: ContentTransform? = nil,
+        popTransitionSpec: ContentTransform? = nil,
+        predictivePopTransitionSpec: ContentTransform? = nil
+    )
+
+    public init(_ transitionSpecs: ContentTransform?)
+
+    public func copy(
+        transitionSpec: ContentTransform? = self.transitionSpec,
+        popTransitionSpec: ContentTransform? = self.popTransitionSpec,
+        predictivePopTransitionSpec: ContentTransform? = self.predictivePopTransitionSpec
+    ) -> NavDisplayTransitionOptions
+    #endif
+}
+```
+
+Your closure can either return your own instance of `NavDisplayTransitionOptions`, or a copy of the provided options, changing just one of the transitions.
+
+```swift
+#if os(Android)
+.tabViewTransitions { options in
+    NavDisplayTransitionOptions(.none)
+}
+.navigationStackTransitions { _ in
+    options.copy(predictivePopTransition: .fade)
+}
+#endif
+```
+
+In transpiled `#if SKIP` code, you can specify a custom animation spec. (In Skip Fuse, you'd use [`composeModifier`](#composemodifier) for that.)
+
+```swift
+#if os(Android)
+.composeModifier {
+    CustomNavigationAnimationSpecModifier()
+}
+#endif
+
+// ...
+
+#if SKIP
+struct CustomNavigationAnimationSpecModifier : ContentModifier {
+    func modify(view: any View) -> any View {
+        view.composeModifier {
+            $0.navigationStackTransitions { _ in
+                NavDisplayTransitionOptions(
+                    // this example is just .slideAndFade, but you could customize it however you like
+                    (slideInHorizontally { $0 } + fadeIn()).togetherWith(slideOutHorizontally { -$0 } + fadeOut())
+                )
+            }
+        }
+    }
+}
+#endif
+```
 #### Modals
 
 Skip supports standard modal presentations. Android apps typically allow users to dismiss modals with the Android back button. Skip allows you to selectively disable this behavior with the Android-only `backDismissDisabled(_ isDisabled: Bool = true)` SwiftUI modifier. If you use this modifier, you **must** put it on the top-level view embedded in your `.sheet` or `.fullScreenCover`, as in the following example:

diff --git a/Sources/SkipUI/SkipUI/Containers/Navigation.swift b/Sources/SkipUI/SkipUI/Containers/Navigation.swift
@@ -4,6 +4,8 @@
 import Foundation
 #if SKIP
 import androidx.activity.compose.BackHandler
+import androidx.compose.animation.AnimatedContentTransitionScope
+import androidx.compose.animation.ContentTransform
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
 import androidx.compose.animation.slideInHorizontally
@@ -85,7 +87,11 @@ import androidx.navigation3.runtime.NavKey
 import androidx.navigation3.runtime.entryProvider
 import androidx.navigation3.runtime.rememberNavBackStack
 import androidx.navigation3.runtime.rememberSaveableStateHolderNavEntryDecorator
+import androidx.navigation3.scene.Scene
 import androidx.navigation3.ui.NavDisplay
+import androidx.navigation3.ui.defaultPopTransitionSpec
+import androidx.navigation3.ui.defaultPredictivePopTransitionSpec
+import androidx.navigation3.ui.defaultTransitionSpec
 import kotlin.reflect.full.superclasses
 import kotlinx.serialization.Serializable
 import androidx.compose.runtime.key
@@ -205,18 +211,20 @@ public struct NavigationStack : View, Renderable {
                             }
                         }
                     }
+                    let defaults = NavDisplayTransitionOptions.navigationStackDefaults
+                    let transitions = EnvironmentValues.shared._navigationStackTransitions?(defaults) ?? defaults
                     NavDisplay(
                         backStack: navBackStack,
                         modifier: modifier,
                         onBack: { navigator.value.navigateBack() },
                         transitionSpec: {
-                            // SKIP INSERT: slideInHorizontally { it } + fadeIn() togetherWith slideOutHorizontally { -it } + fadeOut()
+                            transitions.transitionSpec ?? defaultTransitionSpec<NavKey>()()
                         },
                         popTransitionSpec: {
-                            // SKIP INSERT: slideInHorizontally { -it } + fadeIn() togetherWith slideOutHorizontally { it } + fadeOut()
+                            transitions.popTransitionSpec ?? defaultPopTransitionSpec<NavKey>()()
                         },
-                        predictivePopTransitionSpec: { _ in
-                            // SKIP INSERT: slideInHorizontally { -it } + fadeIn() togetherWith slideOutHorizontally { it } + fadeOut()
+                        predictivePopTransitionSpec: { edge in
+                            transitions.predictivePopTransitionSpec ?? defaultPredictivePopTransitionSpec<NavKey>()(edge)
                         },
                         entryDecorators: decoratorList,
                         entryProvider: entryProvider
@@ -1383,6 +1391,11 @@ extension View {
         return environment(\._material3BottomAppBar, options, affectsEvaluate: false)
     }
 
+    // SKIP @bridge
+    public func navigationStackTransitions(_ options: @escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions) -> View {
+        return environment(\._navigationStackTransitions, options, affectsEvaluate: false)
+    }
+
     public func navigationStackLayoutHints(expectedTitle: Text = NavigationTitlePreferenceKey.defaultValue, expectedTitleDisplayMode: ToolbarTitleDisplayMode? = nil) -> View {
         return environment(
             \._navigationStackLayoutHints,
@@ -1513,6 +1526,94 @@ public struct Material3BottomAppBarOptions {
     }
 }
 
+// SKIP @bridge
+public struct NavDisplayTransitionOptions {
+    // SKIP @bridgeMembers
+    public enum TransitionPreset: Sendable {
+        case `default`
+        case slide
+        case slideAndFade
+        case fade
+        case none
+
+        // SKIP @nobridge
+        var contentTransform: ContentTransform? {
+            switch self {
+            case .default:
+                // This will use NavDisplay.defaultTransitionSpec, .defaultPopTransitionSpec, and .defaultPredictivePopTransitionSpec
+                return nil
+            case .slide:
+                return slideInHorizontally { $0 }.togetherWith(slideOutHorizontally { -$0 })
+            case .slideAndFade:
+                return (slideInHorizontally { $0 } + fadeIn()).togetherWith(slideOutHorizontally { -$0 } + fadeOut())
+            case .fade:
+                return fadeIn().togetherWith(fadeOut())
+            case .none:
+                return fadeIn(animationSpec: tween(0)).togetherWith(fadeOut(animationSpec: tween(0)))
+            }
+        }
+    }
+
+    public let transitionSpec: ContentTransform?
+    public let popTransitionSpec: ContentTransform?
+    public let predictivePopTransitionSpec: ContentTransform?
+
+    public init(transitionSpec: ContentTransform? = nil, popTransitionSpec: ContentTransform? = nil, predictivePopTransitionSpec: ContentTransform? = nil) {
+        self.transitionSpec = transitionSpec
+        self.popTransitionSpec = popTransitionSpec
+        self.predictivePopTransitionSpec = predictivePopTransitionSpec
+    }
+
+    public init(_ transitionSpecs: ContentTransform?) {
+        self.transitionSpec = transitionSpecs
+        self.popTransitionSpec = transitionSpecs
+        self.predictivePopTransitionSpec = transitionSpecs
+    }
+
+    // SKIP @bridge
+    public init(_ transitionPreset: TransitionPreset) {
+        self.transitionSpec = transitionPreset.contentTransform
+        self.popTransitionSpec = transitionPreset.contentTransform
+        self.predictivePopTransitionSpec = transitionPreset.contentTransform
+    }
+
+    // SKIP @bridge
+    public static var navigationStackDefaults: NavDisplayTransitionOptions {
+        NavDisplayTransitionOptions(.slideAndFade)
+    }
+
+    // SKIP @bridge
+    public static var tabViewDefaults: NavDisplayTransitionOptions {
+        NavDisplayTransitionOptions()
+    }
+
+    public func copy(
+        transitionSpec: ContentTransform? = self.transitionSpec,
+        popTransitionSpec: ContentTransform? = self.popTransitionSpec,
+        predictivePopTransitionSpec: ContentTransform? = self.predictivePopTransitionSpec
+    ) -> NavDisplayTransitionOptions {
+        NavDisplayTransitionOptions(
+            transitionSpec: transitionSpec,
+            popTransitionSpec: popTransitionSpec,
+            predictivePopTransitionSpec: predictivePopTransitionSpec
+        )
+    }
+
+    /// Preset-based updates. Pass `nil` for a slot to leave `self`’s value unchanged.
+    // SKIP @bridge
+    public func copy(
+        transition: TransitionPreset? = nil,
+        popTransition: TransitionPreset? = nil,
+        predictivePopTransition: TransitionPreset? = nil
+    ) -> NavDisplayTransitionOptions {
+        return copy(
+            transitionSpec: transition == .default ? nil : (transition?.contentTransform ?? transitionSpec),
+            popTransitionSpec: popTransition == .default ? nil : (popTransition?.contentTransform ?? popTransitionSpec),
+            predictivePopTransitionSpec: predictivePopTransition == .default ? nil : (predictivePopTransition?.contentTransform ?? predictivePopTransitionSpec)
+        )
+    }
+}
+
 struct NavigationDestinationsPreferenceKey: PreferenceKey {
     static let defaultValue: NavigationDestinations = [:]
 

diff --git a/Sources/SkipUI/SkipUI/Containers/TabView.swift b/Sources/SkipUI/SkipUI/Containers/TabView.swift
@@ -78,6 +78,9 @@ import androidx.navigation3.runtime.rememberDecoratedNavEntries
 import androidx.navigation3.runtime.rememberNavBackStack
 import androidx.navigation3.runtime.rememberSaveableStateHolderNavEntryDecorator
 import androidx.navigation3.ui.NavDisplay
+import androidx.navigation3.ui.defaultPopTransitionSpec
+import androidx.navigation3.ui.defaultPredictivePopTransitionSpec
+import androidx.navigation3.ui.defaultTransitionSpec
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import kotlinx.serialization.Serializable
@@ -516,6 +519,8 @@ public struct TabView : View, Renderable {
                                 tabIndex += 1
                             }
                             let activeEntries = decoratedEntrySlots[selectedTabIndex.value]!
+                            let defaults = NavDisplayTransitionOptions.tabViewDefaults
+                            let transitions = EnvironmentValues.shared._tabViewTransitions?(defaults) ?? defaults
                             NavDisplay(
                                 entries: activeEntries,
                                 modifier: Modifier.fillMaxSize(),
@@ -524,6 +529,15 @@ public struct TabView : View, Renderable {
                                         activeStack.removeLastOrNull()
                                     }
                                 },
+                                transitionSpec: {
+                                    transitions.transitionSpec ?? defaultTransitionSpec<NavKey>()()
+                                },
+                                popTransitionSpec: {
+                                    transitions.popTransitionSpec ?? defaultPopTransitionSpec<NavKey>()()
+                                },
+                                predictivePopTransitionSpec: { edge in
+                                    transitions.predictivePopTransitionSpec ?? defaultPredictivePopTransitionSpec<NavKey>()(edge)
+                                }
                             )
                         }
                     )
@@ -1235,6 +1249,11 @@ extension View {
     public func material3NavigationBar(_ options: @Composable (Material3NavigationBarOptions) -> Material3NavigationBarOptions) -> View {
         return environment(\._material3NavigationBar, options, affectsEvaluate: false)
     }
+
+    // SKIP @bridge
+    public func tabViewTransitions(_ options: @escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions) -> View {
+        return environment(\._tabViewTransitions, options, affectsEvaluate: false)
+    }
     #endif
 }
 

diff --git a/Sources/SkipUI/SkipUI/Environment/EnvironmentValues.swift b/Sources/SkipUI/SkipUI/Environment/EnvironmentValues.swift
@@ -791,6 +791,11 @@ extension EnvironmentValues {
         set { setBuiltinValue(key: "_navigationStackLayoutHints", value: newValue, defaultValue: { nil }) }
     }
 
+    var _navigationStackTransitions: (@escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions)? {
+        get { builtinValue(key: "_navigationStackTransitions", defaultValue: { nil }) as! (@escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions)? }
+        set { setBuiltinValue(key: "_navigationStackTransitions", value: newValue, defaultValue: { nil }) }
+    }
+
     /// Nested scroll connection for the active `NavigationStack` entry's top app bar
     public var _nestedScrollConnection: NestedScrollConnection? {
         get { builtinValue(key: "_nestedScrollConnection", defaultValue: { nil }) as! NestedScrollConnection? }
@@ -822,6 +827,11 @@ extension EnvironmentValues {
         set { setBuiltinValue(key: "_tabViewStyle", value: newValue, defaultValue: { nil }) }
     }
 
+    var _tabViewTransitions: (@escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions)? {
+        get { builtinValue(key: "_tabViewTransitions", defaultValue: { nil }) as! (@escaping (NavDisplayTransitionOptions) -> NavDisplayTransitionOptions)? }
+        set { setBuiltinValue(key: "_tabViewTransitions", value: newValue, defaultValue: { nil }) }
+    }
+
     var _safeArea: SafeArea? {
         get { builtinValue(key: "_safeArea", defaultValue: { nil }) as! SafeArea? }
         set { setBuiltinValue(key: "_safeArea", value: newValue, defaultValue: { nil }) }