diff --git a/packages/go/components/chat/chat-input.tsx b/packages/go/components/chat/chat-input.tsx
index 42727361..c7731b1e 100644
--- a/packages/go/components/chat/chat-input.tsx
+++ b/packages/go/components/chat/chat-input.tsx
@@ -135,6 +135,9 @@ export function ChatInput({ onSend, disabled, className, agents = [], draft, onD
   };
 
   const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    // Ignore Enter during IME composition (Chinese, Japanese, Korean input)
+    if (e.nativeEvent.isComposing || e.key === 'Process') return;
+
     if (showMentions && filteredAgents.length > 0) {
       if (e.key === 'ArrowDown') {
         e.preventDefault();
diff --git a/sdk/studio/src/pages/messaging/components/MessageInput.tsx b/sdk/studio/src/pages/messaging/components/MessageInput.tsx
index 04e1b6d1..4847271e 100644
--- a/sdk/studio/src/pages/messaging/components/MessageInput.tsx
+++ b/sdk/studio/src/pages/messaging/components/MessageInput.tsx
@@ -715,6 +715,9 @@ const MessageInput: React.FC<MessageInputProps> = ({
   }
 
   const handleKeyDown = (e: React.KeyboardEvent) => {
+    // Ignore Enter during IME composition (Chinese, Japanese, Korean input)
+    if (e.nativeEvent.isComposing || e.key === 'Process') return;
+
     // Handle mention navigation
     if (showMentions && filteredAgents.length > 0) {
       if (e.key === "ArrowDown") {
diff --git a/workspace/frontend/components/chat/chat-input.tsx b/workspace/frontend/components/chat/chat-input.tsx
index 42727361..c7731b1e 100644
--- a/workspace/frontend/components/chat/chat-input.tsx
+++ b/workspace/frontend/components/chat/chat-input.tsx
@@ -135,6 +135,9 @@ export function ChatInput({ onSend, disabled, className, agents = [], draft, onD
   };
 
   const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    // Ignore Enter during IME composition (Chinese, Japanese, Korean input)
+    if (e.nativeEvent.isComposing || e.key === 'Process') return;
+
     if (showMentions && filteredAgents.length > 0) {
       if (e.key === 'ArrowDown') {
         e.preventDefault();