diff --git a/packages/ui/src/components/chat/ChatInput.tsx b/packages/ui/src/components/chat/ChatInput.tsx
index 1a8f5645..7616c8f5 100644
--- a/packages/ui/src/components/chat/ChatInput.tsx
+++ b/packages/ui/src/components/chat/ChatInput.tsx
@@ -47,6 +47,16 @@ interface ChatInputProps {
 
 const isPrimaryMode = (mode?: string) => mode === 'primary' || mode === 'all' || mode === undefined || mode === null;
 
+/**
+ * Detects if a keyboard event is part of IME composition.
+ * Uses both isComposing and keyCode === 229 (MDN recommended).
+ * WebKit may fire compositionend before keydown, causing isComposing to be false
+ * while keyCode remains 229, so both checks are needed.
+ */
+const isIMECompositionEvent = (e: React.KeyboardEvent): boolean => {
+    return e.nativeEvent.isComposing || e.nativeEvent.keyCode === 229;
+};
+
 export const ChatInput: React.FC<ChatInputProps> = ({ onOpenSettings, scrollToBottom }) => {
     const [message, setMessage] = React.useState('');
     const [isDragging, setIsDragging] = React.useState(false);
@@ -476,6 +486,9 @@ export const ChatInput: React.FC<ChatInputProps> = ({ onOpenSettings, scrollToBo
     }, [sessionPhase, queuedMessages.length, currentSessionId, currentProviderId, currentModelId, sessionAbortFlags]);
 
     const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+        // Early return during IME composition to prevent interference with autocomplete
+        // Uses keyCode === 229 fallback for WebKit where compositionend fires before keydown
+        if (isIMECompositionEvent(e)) return;
 
         if (showCommandAutocomplete && commandRef.current) {
             if (e.key === 'Enter' || e.key === 'ArrowUp' || e.key === 'ArrowDown' || e.key === 'Escape' || e.key === 'Tab') {
@@ -508,7 +521,7 @@ export const ChatInput: React.FC<ChatInputProps> = ({ onOpenSettings, scrollToBo
         }
 
         // Handle Enter/Ctrl+Enter based on queue mode
-        if (e.key === 'Enter' && !e.shiftKey && !isMobile) {
+        if (e.key === 'Enter' && !e.shiftKey && !isMobile && !isIMECompositionEvent(e)) {
             e.preventDefault();
             
             const isCtrlEnter = e.ctrlKey || e.metaKey;
diff --git a/packages/ui/src/components/views/agent-manager/AgentManagerEmptyState.tsx b/packages/ui/src/components/views/agent-manager/AgentManagerEmptyState.tsx
index ac0322b9..9e324d87 100644
--- a/packages/ui/src/components/views/agent-manager/AgentManagerEmptyState.tsx
+++ b/packages/ui/src/components/views/agent-manager/AgentManagerEmptyState.tsx
@@ -23,6 +23,16 @@ const MAX_FILE_SIZE = 10 * 1024 * 1024;
 /** Max number of concurrent runs */
 const MAX_MODELS = 5;
 
+/**
+ * Detects if a keyboard event is part of IME composition.
+ * Uses both isComposing and keyCode === 229 (MDN recommended).
+ * WebKit may fire compositionend before keydown, causing isComposing to be false
+ * while keyCode remains 229, so both checks are needed.
+ */
+const isIMECompositionEvent = (e: React.KeyboardEvent): boolean => {
+    return e.nativeEvent.isComposing || e.nativeEvent.keyCode === 229;
+};
+
 /** Attached file for agent manager */
 interface AttachedFile {
   id: string;
@@ -177,8 +187,11 @@ export const AgentManagerEmptyState: React.FC<AgentManagerEmptyStateProps> = ({
   };
 
   const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    // Early return during IME composition
+    if (isIMECompositionEvent(e)) return;
+
     // Enter submits if valid, Shift+Enter adds newline
-    if (e.key === 'Enter' && !e.shiftKey) {
+    if (e.key === 'Enter' && !e.shiftKey && !isIMECompositionEvent(e)) {
       e.preventDefault();
       if (isValid && !isSubmittingOrCreating) {
         handleSubmit(e as unknown as React.FormEvent);