diff --git a/packages/app/e2e/mobile/agent-device/native-user-message-preview-preconditions.md b/packages/app/e2e/mobile/agent-device/native-user-message-preview-preconditions.md
new file mode 100644
index 0000000000..9985a3f544
--- /dev/null
+++ b/packages/app/e2e/mobile/agent-device/native-user-message-preview-preconditions.md
@@ -0,0 +1,14 @@
+# Native user message preview
+
+Open a chat with a user message containing 16 newline-separated lines of
+`Preview line N`, with N from 1 to 16. Scroll the message into view on a
+phone-sized Android emulator or iOS simulator. Its text must exceed the 240-point preview cap,
+while its expanded bubble and toggle fit in the chat viewport. Close any other
+expanded messages so the toggle labels identify this message.
+
+Replay `native-user-message-preview.android.ad` or
+`native-user-message-preview.ios.ad` through the existing mobile runner or
+agent-device. It checks that a clipped message offers Show more and
+that two expand/collapse round trips keep both controls reachable. Before the
+fix, the first Show more assertion fails because native layout reports the
+capped height as the full content height.
diff --git a/packages/app/e2e/mobile/agent-device/native-user-message-preview.android.ad b/packages/app/e2e/mobile/agent-device/native-user-message-preview.android.ad
new file mode 100644
index 0000000000..45630217bb
--- /dev/null
+++ b/packages/app/e2e/mobile/agent-device/native-user-message-preview.android.ad
@@ -0,0 +1,14 @@
+context platform=android timeout=60000 retries=0
+env APP_ID=sh.paseo.debug
+
+open "${APP_ID}"
+wait "role=\"button\" label=\"Show more\"" 10000
+press "role=\"button\" label=\"Show more\""
+wait "role=\"button\" label=\"Show less\"" 10000
+press "role=\"button\" label=\"Show less\""
+wait "role=\"button\" label=\"Show more\"" 10000
+press "role=\"button\" label=\"Show more\""
+wait "role=\"button\" label=\"Show less\"" 10000
+press "role=\"button\" label=\"Show less\""
+wait "role=\"button\" label=\"Show more\"" 10000
+close
diff --git a/packages/app/e2e/mobile/agent-device/native-user-message-preview.ios.ad b/packages/app/e2e/mobile/agent-device/native-user-message-preview.ios.ad
new file mode 100644
index 0000000000..d19d7dd8aa
--- /dev/null
+++ b/packages/app/e2e/mobile/agent-device/native-user-message-preview.ios.ad
@@ -0,0 +1,14 @@
+context platform=ios timeout=60000 retries=0
+env APP_ID=sh.paseo.debug
+
+open "${APP_ID}"
+wait "role=\"button\" label=\"Show more\"" 10000
+press "role=\"button\" label=\"Show more\""
+wait "role=\"button\" label=\"Show less\"" 10000
+press "role=\"button\" label=\"Show less\""
+wait "role=\"button\" label=\"Show more\"" 10000
+press "role=\"button\" label=\"Show more\""
+wait "role=\"button\" label=\"Show less\"" 10000
+press "role=\"button\" label=\"Show less\""
+wait "role=\"button\" label=\"Show more\"" 10000
+close
diff --git a/packages/app/src/components/user-message/index.tsx b/packages/app/src/components/user-message/index.tsx
index ba383eb0d3..5f5eef4ba6 100644
--- a/packages/app/src/components/user-message/index.tsx
+++ b/packages/app/src/components/user-message/index.tsx
@@ -1,5 +1,5 @@
 import { useState, useCallback, useMemo, type ReactNode } from "react";
-import { View, type LayoutChangeEvent } from "react-native";
+import { View, type LayoutChangeEvent, type ViewStyle } from "react-native";
 import { StyleSheet } from "react-native-unistyles";
 import { useTranslation } from "react-i18next";
 import type { AgentMessage } from "@getpaseo/protocol/agent-message";
@@ -8,23 +8,29 @@ import { EdgeFade } from "@/components/ui/edge-fade";
 import { useProviderIcon } from "@/components/provider-icons";
 import { useSessionStore } from "@/stores/session-store";
 import { navigateToAgent } from "@/utils/navigate-to-agent";
+import { isNative } from "@/constants/platform";
 
 const PREVIEW_HEIGHT = 240;
+// Native View still clips with "scroll", but Yoga measures its children without
+// the height cap. "hidden" caps the measured body too, hiding the expand control.
+const previewStyle: ViewStyle = {
+  maxHeight: PREVIEW_HEIGHT,
+  overflow: isNative ? "scroll" : "hidden",
+};
 
 export function MessagePreview({ children }: { children: ReactNode }) {
   const { t } = useTranslation();
   const [expanded, setExpanded] = useState(false);
-  const [height, setHeight] = useState(0);
-  const overflowing = height > PREVIEW_HEIGHT;
+  const [overflowing, setOverflowing] = useState(false);
   const measure = useCallback(
-    (event: LayoutChangeEvent) => setHeight(event.nativeEvent.layout.height),
+    (event: LayoutChangeEvent) => setOverflowing(event.nativeEvent.layout.height > PREVIEW_HEIGHT),
     [],
   );
   const toggle = useCallback(() => setExpanded((value) => !value), []);
   const accessibilityState = useMemo(() => ({ expanded }), [expanded]);
   return (
     <>
-      <View style={!expanded && styles.preview}>
+      <View style={!expanded && previewStyle}>
         <View style={styles.body} onLayout={measure}>
           {children}
         </View>
@@ -83,7 +89,6 @@ export function MessageSender({
 }
 
 const styles = StyleSheet.create((theme) => ({
-  preview: { maxHeight: PREVIEW_HEIGHT, overflow: "hidden" },
   body: { flexShrink: 0 },
   sender: { paddingRight: 0, borderRightWidth: 0 },
   toggle: { alignSelf: "flex-start", paddingHorizontal: 0, minHeight: 0, borderWidth: 0 },