replace react-nav header hack with scroll edge interaction module

- new expo-scroll-edge-interaction native module (iOS-only) that sets up
  UIScrollEdgeElementContainerInteraction on iOS 26+
- new ScrollEdgeInteractionProvider context and hooks
- Layout.Screen gains `transparentHeader` prop
- Layout.Header.Outer auto-detects transparent mode from context
- List auto-registers scroll view and applies content inset

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/expo-scroll-edge-interaction/expo-module.config.json

@@ -0,0 +1,6 @@
+{
+  "platforms": ["ios"],
+  "ios": {
+    "modules": ["ExpoScrollEdgeInteractionModule"]
+  }
+}

modules/expo-scroll-edge-interaction/index.ts

@@ -0,0 +1,2 @@
+export type {ScrollEdgeInteractionEdge} from './src/ExpoScrollEdgeInteraction.types'
+export {ExpoScrollEdgeInteractionView} from './src/ExpoScrollEdgeInteractionView'

modules/expo-scroll-edge-interaction/ios/ExpoScrollEdgeInteraction.podspec

@@ -0,0 +1,21 @@
+Pod::Spec.new do |s|
+  s.name           = 'ExpoScrollEdgeInteraction'
+  s.version        = '1.0.0'
+  s.summary        = 'UIScrollEdgeElementContainerInteraction for React Native views'
+  s.description    = 'UIScrollEdgeElementContainerInteraction for React Native views'
+  s.author         = 'bluesky-social'
+  s.homepage       = 'https://github.com/bluesky-social/social-app'
+  s.platforms      = { :ios => '13.4', :tvos => '13.4' }
+  s.source         = { git: '' }
+  s.static_framework = true
+
+  s.dependency 'ExpoModulesCore'
+
+  # Swift/Objective-C compatibility
+  s.pod_target_xcconfig = {
+    'DEFINES_MODULE' => 'YES',
+    'SWIFT_COMPILATION_MODE' => 'wholemodule'
+  }
+
+  s.source_files = "**/*.{h,m,mm,swift,hpp,cpp}"
+end

modules/expo-scroll-edge-interaction/ios/ExpoScrollEdgeInteractionModule.swift

@@ -0,0 +1,19 @@
+import ExpoModulesCore
+
+public class ExpoScrollEdgeInteractionModule: Module {
+  public func definition() -> ModuleDefinition {
+    Name("ExpoScrollEdgeInteraction")
+
+    View(ExpoScrollEdgeInteractionView.self) {
+      Prop("nodeHandle") { (view: ExpoScrollEdgeInteractionView, prop: Int?) in
+        view.nodeHandle = prop
+      }
+      Prop("scrollViewTag") { (view: ExpoScrollEdgeInteractionView, prop: Int?) in
+        view.scrollViewTag = prop
+      }
+      Prop("edge") { (view: ExpoScrollEdgeInteractionView, prop: String?) in
+        view.edge = prop
+      }
+    }
+  }
+}

modules/expo-scroll-edge-interaction/ios/ExpoScrollEdgeInteractionView.swift

@@ -0,0 +1,73 @@
+import ExpoModulesCore
+import React
+
+class ExpoScrollEdgeInteractionView: ExpoView {
+  var nodeHandle: Int? {
+    didSet {
+      setupInteraction()
+    }
+  }
+
+  var scrollViewTag: Int? {
+    didSet {
+      setupInteraction()
+    }
+  }
+
+  var edge: String? {
+    didSet {
+      setupInteraction()
+    }
+  }
+
+  private var currentInteraction: NSObject?
+
+  private func setupInteraction() {
+    guard #available(iOS 26.0, *) else { return }
+
+    // Clean up old interaction
+    if let interaction = currentInteraction as? UIScrollEdgeElementContainerInteraction,
+       let headerView = findHeaderView() {
+      headerView.removeInteraction(interaction)
+      currentInteraction = nil
+    }
+
+    guard let nodeHandle = nodeHandle,
+          let scrollViewTag = scrollViewTag
+    else { return }
+
+    guard let headerView = appContext?.findView(withTag: nodeHandle, ofType: UIView.self) else {
+      return
+    }
+
+    // RCTScrollView wraps a UIScrollView — get the inner one
+    let scrollView: UIScrollView?
+    if let rctScrollView = appContext?.findView(withTag: scrollViewTag, ofType: RCTScrollView.self) {
+      scrollView = rctScrollView.scrollView
+    } else {
+      scrollView = appContext?.findView(withTag: scrollViewTag, ofType: UIScrollView.self)
+    }
+
+    guard let scrollView = scrollView else { return }
+
+    let interaction = UIScrollEdgeElementContainerInteraction()
+    interaction.edge = resolveEdge()
+    interaction.scrollView = scrollView
+    headerView.addInteraction(interaction)
+    currentInteraction = interaction
+  }
+
+  private func resolveEdge() -> NSDirectionalRectEdge {
+    switch edge {
+    case "bottom": return .bottom
+    case "left": return .leading
+    case "right": return .trailing
+    default: return .top
+    }
+  }
+
+  private func findHeaderView() -> UIView? {
+    guard let nodeHandle = nodeHandle else { return nil }
+    return appContext?.findView(withTag: nodeHandle, ofType: UIView.self)
+  }
+}

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteraction.types.ts

@@ -0,0 +1,11 @@
+import {type ViewStyle} from 'react-native'
+
+export type ScrollEdgeInteractionEdge = 'top' | 'bottom' | 'left' | 'right'
+
+export interface ExpoScrollEdgeInteractionViewProps {
+  nodeHandle: number | null
+  scrollViewTag: number | null
+  edge?: ScrollEdgeInteractionEdge
+  children: React.ReactNode
+  style?: ViewStyle
+}

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteractionView.ios.tsx

@@ -0,0 +1,13 @@
+import {requireNativeViewManager} from 'expo-modules-core'
+
+import {type ExpoScrollEdgeInteractionViewProps} from './ExpoScrollEdgeInteraction.types'
+
+const NativeView: React.ComponentType<ExpoScrollEdgeInteractionViewProps> =
+  requireNativeViewManager('ExpoScrollEdgeInteraction')
+
+export function ExpoScrollEdgeInteractionView({
+  children,
+  ...rest
+}: ExpoScrollEdgeInteractionViewProps) {
+  return <NativeView {...rest}>{children}</NativeView>
+}

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteractionView.tsx

@@ -0,0 +1,7 @@
+import {type ExpoScrollEdgeInteractionViewProps} from './ExpoScrollEdgeInteraction.types'
+
+export function ExpoScrollEdgeInteractionView({
+  children,
+}: React.PropsWithChildren<ExpoScrollEdgeInteractionViewProps>) {
+  return children
+}

src/components/Layout/Header/index.ios.tsx

@@ -1,10 +1,8 @@
-import {useLayoutEffect, useMemo, useState} from 'react'
-import {useWindowDimensions, View} from 'react-native'
-import {useIsFocused, useNavigation} from '@react-navigation/native'
+import {View} from 'react-native'
+import {useSafeAreaInsets} from 'react-native-safe-area-context'
 
-import {type NavigationProp} from '#/lib/routes/types'
-import {atoms as a} from '#/alf'
-import {IS_LIQUID_GLASS} from '#/env'
+import {atoms as a, useGutters} from '#/alf'
+import {useTransparentHeaderProps} from '#/components/Layout/ScrollEdgeInteraction'
 import {Outer as DefaultOuter, type OuterProps} from './index.shared'
 
 export {
@@ -18,68 +16,46 @@ export {
 } from './index.shared'
 
 export function Outer(props: OuterProps) {
-  if (IS_LIQUID_GLASS && props.transparent) {
-    return <TransparentOuter {...props} />
+  const transparentHeaderProps = useTransparentHeaderProps()
+  if (transparentHeaderProps) {
+    return (
+      <TransparentOuter
+        transparentHeaderProps={transparentHeaderProps}
+        {...props}
+      />
+    )
   }
-
   return <DefaultOuter {...props} />
 }
 
-function TransparentOuter({children, headerRef}: OuterProps) {
-  const [headerWidth, setHeaderWidth] = useState(0)
-  const {width: screenWidth} = useWindowDimensions()
+function TransparentOuter({
+  children,
+  transparentHeaderProps,
+}: OuterProps & {
+  transparentHeaderProps: {ref: (node: View | null) => void; onLayout: any}
+}) {
+  const {top} = useSafeAreaInsets()
+  const gutters = useGutters([0, 'base'])
 
-  // bit of a hack - react-native-screens initially renders the header too wide
-  // so let's delay showing it until the padding has been applied -sfn
-  const isInitialRender = headerWidth === 0 || headerWidth === screenWidth
-  const headerElement = useMemo(() => {
-    return (
-      <View
-        ref={headerRef}
-        onLayout={evt => setHeaderWidth(evt.nativeEvent.layout.width)}
-        style={[
-          a.flex_1,
-          a.flex_row,
-          a.align_center,
-          a.gap_sm,
-          // built-in padding, but slightly more on right than left,
-          // so compensate for that. this is because we're using
-          // headerRightItems
-          a.pl_xs,
-          isInitialRender && {opacity: 0},
-        ]}>
-        {children}
-      </View>
-    )
-  }, [children, headerRef, isInitialRender])
-
-  // this is how expo-router handles it
-  // https://github.com/expo/expo/blob/main/packages/expo-router/src/views/Screen.tsx#L34
-  // note: I'm skipping handling preloading for now -sfn
-  const navigation = useNavigation<NavigationProp>()
-  const isFocused = useIsFocused()
-  useLayoutEffect(() => {
-    if (isFocused) {
-      navigation.setOptions({
-        headerShown: true,
-        // abuse the headerItems API so we get
-        // the sweet sweet progressive blur header.
-        // unclear why just `header: () => elem` doesn't work -sfn
-        unstable_headerRightItems: () => [
-          {
-            type: 'custom',
-            element: headerElement,
-            hidesSharedBackground: true,
-          },
-        ],
-        headerTransparent: true,
-        headerBackVisible: false,
-        scrollEdgeEffects: {
-          top: 'soft',
-        },
-      })
-    }
-  }, [isFocused, navigation, headerElement])
-
-  return null
+  return (
+    <View
+      collapsable={false}
+      ref={transparentHeaderProps.ref}
+      onLayout={transparentHeaderProps.onLayout}
+      style={[
+        a.absolute,
+        a.top_0,
+        a.left_0,
+        a.right_0,
+        a.z_10,
+        a.flex_row,
+        a.align_center,
+        a.gap_sm,
+        gutters,
+        {paddingTop: top, minHeight: 48 + top},
+        a.pb_xs,
+      ]}>
+      {children}
+    </View>
+  )
 }

src/components/Layout/Header/index.shared.tsx

@@ -35,22 +35,6 @@ export type OuterProps = {
   noBottomBorder?: boolean
   headerRef?: React.RefObject<View | null>
   sticky?: boolean
-  /**
-   * Use native transparent blurred header on iOS 26 (looks very nice)
-   *
-   * When using this, make sure to enable these props on the scrollview for the screen:
-   * ```tsx
-   * <Layout.Content
-   *   contentInsetAdjustmentBehavior="automatic"
-   *   automaticallyAdjustsScrollIndicatorInsets
-   *   // everything else
-   * />
-   * ```
-   * and also set `noInsetTop={IS_LIQUID_GLASS}` on `Layout.Screen`
-   *
-   * @platform ios
-   * */
-  transparent?: boolean
 }
 
 export function Outer({

src/components/Layout/ScrollEdgeInteraction.tsx

@@ -0,0 +1,118 @@
+import {createContext, useContext, useRef, useState} from 'react'
+import {findNodeHandle, type LayoutChangeEvent, type View} from 'react-native'
+
+import {atoms as a} from '#/alf'
+import {IS_LIQUID_GLASS} from '#/env'
+import {
+  ExpoScrollEdgeInteractionView,
+  type ScrollEdgeInteractionEdge,
+} from '../../../modules/expo-scroll-edge-interaction'
+
+interface ScrollEdgeContextValue {
+  setNodeHandle: (update: React.SetStateAction<number | null>) => void
+  setScrollViewTag: (update: React.SetStateAction<number | null>) => void
+  setHeaderHeight: (height: number) => void
+}
+
+const ScrollEdgeContext = createContext<ScrollEdgeContextValue | null>(null)
+const ScrollEdgeHeightContext = createContext<number | null>(null)
+
+export function ScrollEdgeInteractionProvider({
+  children,
+  edge = 'top',
+}: {
+  children: React.ReactNode
+  edge?: ScrollEdgeInteractionEdge
+}) {
+  const [nodeHandle, setNodeHandle] = useState<number | null>(null)
+  const [scrollViewTag, setScrollViewTag] = useState<number | null>(null)
+  const [headerHeight, setHeaderHeight] = useState(0)
+
+  if (!IS_LIQUID_GLASS) {
+    return children
+  }
+
+  return (
+    <ScrollEdgeContext.Provider
+      value={{setNodeHandle, setScrollViewTag, setHeaderHeight}}>
+      <ScrollEdgeHeightContext.Provider value={headerHeight}>
+        <ExpoScrollEdgeInteractionView
+          nodeHandle={nodeHandle}
+          scrollViewTag={scrollViewTag}
+          edge={edge}
+          style={a.flex_1}>
+          {children}
+        </ExpoScrollEdgeInteractionView>
+      </ScrollEdgeHeightContext.Provider>
+    </ScrollEdgeContext.Provider>
+  )
+}
+
+/**
+ * Returns a ref callback to attach to the header view. The native module
+ * will add a UIScrollEdgeElementContainerInteraction to this view.
+ * Returns undefined when there's no provider (non-Liquid Glass).
+ */
+export function useTransparentHeaderProps() {
+  const ctx = useContext(ScrollEdgeContext)
+  // Track which handle this specific hook instance set, so that
+  // unmounting one header doesn't clobber another's handle.
+  const ourHandle = useRef<number | null>(null)
+
+  if (!ctx) return undefined
+
+  const {setNodeHandle, setHeaderHeight} = ctx
+
+  const refCallback = (node: View | null) => {
+    const handle = node ? findNodeHandle(node) : null
+    if (handle !== null) {
+      ourHandle.current = handle
+      setNodeHandle(handle)
+    } else {
+      // Only clear if we were the last one to set it
+      const prev = ourHandle.current
+      ourHandle.current = null
+      setNodeHandle(cur => (cur === prev ? null : cur))
+    }
+  }
+
+  const onLayout = (e: LayoutChangeEvent) => {
+    setHeaderHeight(e.nativeEvent.layout.height)
+  }
+
+  return {ref: refCallback, onLayout}
+}
+
+/**
+ * Registers a scroll view with the scroll edge interaction provider.
+ * Called automatically by List.
+ * Returns a ref callback, or undefined if no provider.
+ */
+export function useScrollEdgeScrollView() {
+  const ctx = useContext(ScrollEdgeContext)
+  const ourTag = useRef<number | null>(null)
+
+  if (!ctx) return undefined
+
+  const {setScrollViewTag} = ctx
+
+  return (node: any) => {
+    const tag = node ? findNodeHandle(node) : null
+    if (tag !== null) {
+      ourTag.current = tag
+      setScrollViewTag(tag)
+    } else {
+      const prev = ourTag.current
+      ourTag.current = null
+      setScrollViewTag(cur => (cur === prev ? null : cur))
+    }
+  }
+}
+
+/**
+ * Returns the measured header height, or null if not inside a
+ * transparent header provider.
+ */
+export function useTransparentHeaderHeight(): number | null {
+  return useContext(ScrollEdgeHeightContext)
+}

src/components/Layout/index.tsx

@@ -22,32 +22,63 @@ import {
 import {useDialogContext} from '#/components/Dialog'
 import {CENTER_COLUMN_OFFSET, SCROLLBAR_OFFSET} from '#/components/Layout/const'
 import {ScrollbarOffsetContext} from '#/components/Layout/context'
+import {ScrollEdgeInteractionProvider} from '#/components/Layout/ScrollEdgeInteraction'
 import {IS_WEB} from '#/env'
 
 export * from '#/components/Layout/const'
 export * as Header from '#/components/Layout/Header'
+export {useTransparentHeaderHeight} from '#/components/Layout/ScrollEdgeInteraction'
 
 export type ScreenProps = React.ComponentProps<typeof View> & {
   style?: StyleProp<ViewStyle>
   noInsetTop?: boolean
+  /**
+   * Enables a transparent, absolutely-positioned header with the iOS 26
+   * Liquid Glass scroll-edge blur effect. When set, wraps screen children
+   * in a `ScrollEdgeInteractionProvider`, implies `noInsetTop`, and causes
+   * `Layout.Header.Outer` to render as a transparent overlay.
+   *
+   * The blur effect only works with `List` (native FlatList), not with
+   * `Layout.Content` (Animated.ScrollView). `List` automatically picks up
+   * the header height and applies `contentInset`.
+   *
+   * On non-Liquid-Glass devices this is a no-op.
+   *
+   * @platform ios
+   */
+  transparentHeader?: boolean
 }
 
 /**
  * Outermost component of every screen
  */
 export const Screen = memo(function Screen({
+  children,
   style,
   noInsetTop,
+  transparentHeader,
   ...props
 }: ScreenProps) {
   const {top} = useSafeAreaInsets()
+  const skipInsetTop = noInsetTop || transparentHeader
   return (
     <>
       {IS_WEB && <WebCenterBorders />}
       <View
-        style={[a.util_screen_outer, {paddingTop: noInsetTop ? 0 : top}, style]}
-        {...props}
-      />
+        style={[
+          a.util_screen_outer,
+          {paddingTop: skipInsetTop ? 0 : top},
+          style,
+        ]}
+        {...props}>
+        {transparentHeader ? (
+          <ScrollEdgeInteractionProvider>
+            {children}
+          </ScrollEdgeInteractionProvider>
+        ) : (
+          children
+        )}
+      </View>
     </>
   )
 })

src/components/dms/MessagesListHeader.tsx

@@ -55,7 +55,7 @@ export function MessagesListHeader({
   }, [moderation])
 
   return (
-    <Layout.Header.Outer transparent>
+    <Layout.Header.Outer>
       <View style={[a.flex_1, a.flex_row, a.gap_xs, a.align_start]}>
         <View style={[{minHeight: PFP_SIZE}, a.justify_center]}>
           <Layout.Header.BackButton />

src/screens/Messages/Conversation.tsx

@@ -89,7 +89,7 @@ export function MessagesConversationScreenInner({route}: Props) {
     <Layout.Screen
       testID="convoScreen"
       style={web([{minHeight: 0}, a.flex_1])}
-      noInsetTop={IS_LIQUID_GLASS}>
+      transparentHeader={IS_LIQUID_GLASS}>
       <ConvoProvider key={convoId} convoId={convoId}>
         <Inner />
       </ConvoProvider>

src/view/com/util/List.tsx

@@ -6,14 +6,20 @@ import {
   useAnimatedScrollHandler,
   useSharedValue,
 } from 'react-native-reanimated'
+import {useSafeAreaInsets} from 'react-native-safe-area-context'
 import {updateActiveVideoViewAsync} from '@haileyok/bluesky-video'
 
 import {useDedupe} from '#/lib/hooks/useDedupe'
 import {useNonReactiveCallback} from '#/lib/hooks/useNonReactiveCallback'
+import {mergeRefs} from '#/lib/merge-refs'
 import {useScrollHandlers} from '#/lib/ScrollContext'
 import {addStyle} from '#/lib/styles'
 import {useLightbox} from '#/state/lightbox'
 import {useTheme} from '#/alf'
+import {
+  useScrollEdgeScrollView,
+  useTransparentHeaderHeight,
+} from '#/components/Layout/ScrollEdgeInteraction'
 import {IS_IOS} from '#/env'
 import {FlatList_INTERNAL} from './Views'
 
@@ -54,6 +60,7 @@ let List = forwardRef<ListMethods, ListProps>(
       headerOffset,
       style,
       progressViewOffset,
+      contentInset,
       automaticallyAdjustsScrollIndicatorInsets = false,
       ...props
     },
@@ -63,6 +70,13 @@ let List = forwardRef<ListMethods, ListProps>(
     const t = useTheme()
     const dedupe = useDedupe(400)
     const scrollsToTop = useAllowScrollToTop()
+    const transparentHeaderRef = useScrollEdgeScrollView()
+    const insets = useSafeAreaInsets()
+    const transparentHeaderHeight = useTransparentHeaderHeight()
+    const isHeaderTransparent = transparentHeaderHeight != null
+    const headerHeight = isHeaderTransparent
+      ? transparentHeaderHeight - insets.top
+      : undefined
 
     const handleScrolledDownChange = useNonReactiveCallback(
       (didScrollDown: boolean) => {
@@ -163,10 +177,18 @@ let List = forwardRef<ListMethods, ListProps>(
           automaticallyAdjustsScrollIndicatorInsets
         }
         scrollIndicatorInsets={{
-          top: headerOffset,
+          top: headerHeight || headerOffset,
           right: 1,
           ...props.scrollIndicatorInsets,
         }}
+        contentInset={
+          headerHeight
+            ? {
+                ...contentInset,
+                top: headerHeight,
+              }
+            : contentInset
+        }
         indicatorStyle={t.scheme === 'dark' ? 'white' : 'black'}
         contentOffset={contentOffset}
         refreshControl={refreshControl}
@@ -175,7 +197,9 @@ let List = forwardRef<ListMethods, ListProps>(
         scrollEventThrottle={1}
         style={style}
         // @ts-expect-error FlatList_INTERNAL ref type is wrong -sfn
-        ref={ref}
+        ref={
+          transparentHeaderRef ? mergeRefs([ref, transparentHeaderRef]) : ref
+        }
       />
     )
   },