diff --git a/src/components/Chat.tsx b/src/components/Chat.tsx
index c255c5b..c295427 100644
--- a/src/components/Chat.tsx
+++ b/src/components/Chat.tsx
@@ -1,6 +1,6 @@
 import { useEffect, useRef, useCallback, useState, useMemo } from 'react';
 import { ChatMessageComponent } from './ChatMessage';
-import { ChatInput } from './ChatInput';
+import { ChatInput, type ComposerInsertRequest } from './ChatInput';
 import { TypingIndicator } from './TypingIndicator';
 import type { ChatMessage, ConnectionStatus } from '../types';
 import { Bot, ArrowDown, Loader2, ChevronsDownUp, ChevronsUpDown, Sparkles, Bookmark, Download } from 'lucide-react';
@@ -81,9 +81,14 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
   const [showScrollBtn, setShowScrollBtn] = useState(false);
   const [newMessageCount, setNewMessageCount] = useState(0);
   const [replyTo, setReplyTo] = useState<{ preview: string } | null>(null);
+  const [insertRequest, setInsertRequest] = useState<ComposerInsertRequest | null>(null);
 
   // Clear reply context on session switch
-  useEffect(() => { setReplyTo(null); }, [sessionKey]); // eslint-disable-line react-hooks/set-state-in-effect
+  useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect -- reset transient composer UI when session changes
+    setReplyTo(null);
+    setInsertRequest(null);
+  }, [sessionKey]);
   const prevMessageCountRef = useRef(messages.length);
 
   const checkIfNearBottom = useCallback(() => {
@@ -343,7 +348,19 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
                     </div>
                   )}
                   <div className={`${isActiveMatch ? 'ring-1 ring-pc-accent-light/40 rounded-lg' : ''} ${msg.isArchived ? 'opacity-60' : ''}`}>
-                    <ChatMessageComponent message={msg} onRetry={!isGenerating ? handleSend : undefined} onReply={(preview) => { setReplyTo({ preview }); document.getElementById('chat-input')?.focus(); }} agentAvatarUrl={agentAvatarUrl} isFirstInGroup={isFirstInGroup} isBookmarked={isBookmarked(msg.id)} onToggleBookmark={sessionKey ? () => toggleBookmark(msg.id, sessionKey, (msg.content || '').slice(0, 120), msg.timestamp) : undefined} />
+                    <ChatMessageComponent
+                      message={msg}
+                      onRetry={!isGenerating ? handleSend : undefined}
+                      onReply={(preview) => { setReplyTo({ preview }); document.getElementById('chat-input')?.focus(); }}
+                      onUseSelection={(text) => {
+                        setInsertRequest({ id: `${msg.id}:${Date.now()}`, text });
+                        document.getElementById('chat-input')?.focus();
+                      }}
+                      agentAvatarUrl={agentAvatarUrl}
+                      isFirstInGroup={isFirstInGroup}
+                      isBookmarked={isBookmarked(msg.id)}
+                      onToggleBookmark={sessionKey ? () => toggleBookmark(msg.id, sessionKey, (msg.content || '').slice(0, 120), msg.timestamp) : undefined}
+                    />
                   </div>
                 </div>
             );
@@ -426,7 +443,7 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
           </div>
         )}
       </div>
-      <ChatInput onSend={handleSend} onNewSession={onNewSession} onAbort={onAbort} isGenerating={isGenerating} disabled={status !== 'connected'} sessionKey={sessionKey} replyTo={replyTo} onCancelReply={() => setReplyTo(null)} />
+      <ChatInput onSend={handleSend} onNewSession={onNewSession} onAbort={onAbort} isGenerating={isGenerating} disabled={status !== 'connected'} sessionKey={sessionKey} replyTo={replyTo} onCancelReply={() => setReplyTo(null)} insertRequest={insertRequest} />
     </div>
   );
 }
diff --git a/src/components/ChatInput.tsx b/src/components/ChatInput.tsx
index 9a5b1ac..6ada887 100644
--- a/src/components/ChatInput.tsx
+++ b/src/components/ChatInput.tsx
@@ -18,6 +18,11 @@ export interface ReplyContext {
   preview: string;
 }
 
+export interface ComposerInsertRequest {
+  id: string;
+  text: string;
+}
+
 interface Props {
   onSend: (text: string, attachments?: Array<{ mimeType: string; fileName: string; content: string }>) => void;
   onNewSession?: () => Promise<void>;
@@ -27,6 +32,7 @@ interface Props {
   sessionKey?: string;
   replyTo?: ReplyContext | null;
   onCancelReply?: () => void;
+  insertRequest?: ComposerInsertRequest | null;
 }
 
 const MAX_BASE64_CHARS = 300 * 1024; // ~225KB real, well under 512KB WS limit (JSON overhead + base64 bloat)
@@ -91,7 +97,15 @@ function formatSize(bytes: number): string {
   return `${(bytes / (1024 * 1024)).toFixed(1)}MB`;
 }
 
-export function ChatInput({ onSend, onNewSession, onAbort, isGenerating, disabled, sessionKey, replyTo, onCancelReply }: Props) {
+function toQuotedContext(text: string): string {
+  return text
+    .trim()
+    .split('\n')
+    .map(line => `> ${line}`)
+    .join('\n');
+}
+
+export function ChatInput({ onSend, onNewSession, onAbort, isGenerating, disabled, sessionKey, replyTo, onCancelReply, insertRequest }: Props) {
   const t = useT();
   const { sendOnEnter, toggle: toggleSendShortcut } = useSendShortcut();
   const [text, setText] = useState('');
@@ -106,6 +120,7 @@ export function ChatInput({ onSend, onNewSession, onAbort, isGenerating, disable
   // Per-session draft storage
   const draftsRef = useRef<Map<string, string>>(new Map());
   const prevSessionRef = useRef<string | undefined>(sessionKey);
+  const lastInsertIdRef = useRef<string | null>(null);
 
   // Save draft to previous session and restore draft for new session
   useEffect(() => {
@@ -141,6 +156,30 @@ export function ChatInput({ onSend, onNewSession, onAbort, isGenerating, disable
     }
   }, [sessionKey, disabled]);
 
+  useEffect(() => {
+    if (!insertRequest?.id || lastInsertIdRef.current === insertRequest.id) return;
+    lastInsertIdRef.current = insertRequest.id;
+
+    const quoted = toQuotedContext(insertRequest.text);
+    if (!quoted) return;
+
+    setText(prev => {
+      const next = prev.trim()
+        ? `${prev.replace(/\s*$/, '')}\n\n${quoted}\n\n`
+        : `${quoted}\n\n`;
+
+      requestAnimationFrame(() => {
+        const textarea = textareaRef.current;
+        if (!textarea) return;
+        textarea.focus();
+        const pos = next.length;
+        textarea.setSelectionRange(pos, pos);
+      });
+
+      return next;
+    });
+  }, [insertRequest]);
+
   const addFiles = useCallback(async (fileList: FileList | File[]) => {
     const newFiles: FileAttachment[] = [];
     for (const file of Array.from(fileList)) {
diff --git a/src/components/ChatMessage.tsx b/src/components/ChatMessage.tsx
index ede542b..8445560 100644
--- a/src/components/ChatMessage.tsx
+++ b/src/components/ChatMessage.tsx
@@ -313,6 +313,12 @@ function RawJsonPanel({ message }: { message: ChatMessageType }) {
   );
 }
 
+interface SelectionActionState {
+  text: string;
+  top: number;
+  left: number;
+}
+
 /** Extract plain text from message blocks for clipboard copy */
 function getPlainText(message: ChatMessageType): string {
   if (message.blocks.length > 0) {
@@ -353,11 +359,14 @@ function SystemEventMessage({ message }: { message: ChatMessageType }) {
   );
 }
 
-export const ChatMessageComponent = memo(function ChatMessageComponent({ message: rawMessage, onRetry, onReply, agentAvatarUrl, isFirstInGroup = true, isBookmarked = false, onToggleBookmark }: { message: ChatMessageType; onRetry?: (text: string) => void; onReply?: (preview: string) => void; agentAvatarUrl?: string; isFirstInGroup?: boolean; isBookmarked?: boolean; onToggleBookmark?: () => void }) {
+export const ChatMessageComponent = memo(function ChatMessageComponent({ message: rawMessage, onRetry, onReply, onUseSelection, agentAvatarUrl, isFirstInGroup = true, isBookmarked = false, onToggleBookmark }: { message: ChatMessageType; onRetry?: (text: string) => void; onReply?: (preview: string) => void; onUseSelection?: (text: string) => void; agentAvatarUrl?: string; isFirstInGroup?: boolean; isBookmarked?: boolean; onToggleBookmark?: () => void }) {
   useLocale(); // re-render on locale change
   const { resolvedTheme } = useTheme();
   const isLight = resolvedTheme === 'light';
   const [showRawJson, setShowRawJson] = useState(false);
+  const [selectionAction, setSelectionAction] = useState<SelectionActionState | null>(null);
+  const bubbleRef = useRef<HTMLDivElement>(null);
+  const selectionButtonRef = useRef<HTMLButtonElement>(null);
 
   // Strip webhook/hook scaffolding and webchat envelope from user messages before rendering
   const message = useMemo(() => {
@@ -402,6 +411,69 @@ export const ChatMessageComponent = memo(function ChatMessageComponent({ message
 
   const isUser = message.role === 'user';
 
+  const clearSelectionAction = useCallback(() => {
+    setSelectionAction(null);
+  }, []);
+
+  const updateSelectionAction = useCallback(() => {
+    if (isUser || message.isStreaming || !onUseSelection) {
+      setSelectionAction(null);
+      return;
+    }
+
+    const selection = window.getSelection();
+    const bubble = bubbleRef.current;
+    if (!selection || !bubble || selection.rangeCount === 0 || selection.isCollapsed) {
+      setSelectionAction(null);
+      return;
+    }
+
+    const text = selection.toString().trim();
+    if (!text || text.length > 1500) {
+      setSelectionAction(null);
+      return;
+    }
+
+    const range = selection.getRangeAt(0);
+    const common = range.commonAncestorContainer;
+    if (!bubble.contains(common.nodeType === Node.TEXT_NODE ? common.parentNode : common)) {
+      setSelectionAction(null);
+      return;
+    }
+
+    const rect = range.getBoundingClientRect();
+    if (!rect.width && !rect.height) {
+      setSelectionAction(null);
+      return;
+    }
+
+    setSelectionAction({
+      text,
+      top: Math.max(12, rect.top - 40),
+      left: rect.left + (rect.width / 2),
+    });
+  }, [isUser, message.isStreaming, onUseSelection]);
+
+  useEffect(() => {
+    if (!onUseSelection || isUser) return;
+
+    const handleSelectionChange = () => {
+      requestAnimationFrame(updateSelectionAction);
+    };
+    const handlePointerDown = (e: MouseEvent) => {
+      if (selectionButtonRef.current?.contains(e.target as Node)) return;
+      if (bubbleRef.current?.contains(e.target as Node)) return;
+      clearSelectionAction();
+    };
+
+    document.addEventListener('selectionchange', handleSelectionChange);
+    document.addEventListener('mousedown', handlePointerDown);
+    return () => {
+      document.removeEventListener('selectionchange', handleSelectionChange);
+      document.removeEventListener('mousedown', handlePointerDown);
+    };
+  }, [clearSelectionAction, isUser, onUseSelection, updateSelectionAction]);
+
   // System events render as subtle inline notifications
   if (message.isSystemEvent) {
     return <SystemEventMessage message={rawMessage} />;
@@ -432,13 +504,18 @@ export const ChatMessageComponent = memo(function ChatMessageComponent({ message
 
       {/* Bubble */}
       <div className={`min-w-0 max-w-[80%] ${isUser ? 'text-right' : ''}`}>
-        <div className={`group relative inline-block text-left rounded-3xl px-4 py-3 text-sm leading-relaxed max-w-full overflow-hidden ${
+        <div
+          ref={bubbleRef}
+          onMouseUp={updateSelectionAction}
+          onKeyUp={updateSelectionAction}
+          className={`group relative inline-block text-left rounded-3xl px-4 py-3 text-sm leading-relaxed max-w-full overflow-hidden ${
           isUser
             ? (isLight
                 ? 'bg-[rgba(var(--pc-accent-rgb),0.12)] text-pc-text border border-[rgba(var(--pc-accent-rgb),0.3)]'
                 : 'bg-[rgba(var(--pc-accent-rgb),0.08)] text-pc-text border border-[rgba(var(--pc-accent-rgb),0.2)]')
             : 'bg-pc-elevated/40 text-pc-text border border-pc-border shadow-[0_0_0_1px_rgba(255,255,255,0.03)]'
-        }`}>
+        }`}
+        >
           {/* User-visible text */}
           {!isUser ? (
             <CollapsibleContent content={message.content || ''} isStreaming={message.isStreaming}>
@@ -530,6 +607,30 @@ export const ChatMessageComponent = memo(function ChatMessageComponent({ message
             <RawJsonToggle isOpen={showRawJson} onToggle={() => setShowRawJson(o => !o)} />
           </div>
         </div>
+        {!isUser && selectionAction && onUseSelection && createPortal(
+          <button
+            ref={selectionButtonRef}
+            onMouseDown={(e) => {
+              e.preventDefault();
+              e.stopPropagation();
+            }}
+            onClick={(e) => {
+              e.preventDefault();
+              e.stopPropagation();
+              onUseSelection(selectionAction.text);
+              window.getSelection()?.removeAllRanges();
+              clearSelectionAction();
+            }}
+            className="fixed z-[9999] -translate-x-1/2 inline-flex items-center gap-2 rounded-2xl border border-white/8 bg-[rgba(26,26,29,0.96)] px-3.5 py-2 text-[13px] font-medium text-white shadow-[0_12px_28px_rgba(0,0,0,0.38)] backdrop-blur-xl transition-all hover:bg-[rgba(36,36,40,0.98)]"
+            style={{ top: selectionAction.top, left: selectionAction.left }}
+            aria-label={t('message.askInChat')}
+            title={t('message.askInChat')}
+          >
+            <span className="text-base leading-none text-white/90">❞</span>
+            <span>{t('message.askInChat')}</span>
+          </button>,
+          document.body
+        )}
         {(message.timestamp || wasWebhookMessage || isBookmarked) && (
           <div className={`mt-1 flex items-center gap-1.5 text-[11px] text-pc-text-muted ${isUser ? 'justify-end pr-2' : 'pl-2'}`}>
             {isBookmarked && (
diff --git a/src/lib/i18n.ts b/src/lib/i18n.ts
index b71c48a..6050056 100644
--- a/src/lib/i18n.ts
+++ b/src/lib/i18n.ts
@@ -105,6 +105,7 @@ const en = {
   'message.metadata': 'Message details',
   'message.rawJson': 'Raw JSON',
   'message.hideRawJson': 'Hide raw JSON',
+  'message.askInChat': 'Ask in Chat',
 
   // Timestamps
   'time.yesterday': 'Yesterday',
@@ -295,6 +296,7 @@ const fr: Record<keyof typeof en, string> = {
   'message.metadata': 'Détails du message',
   'message.rawJson': 'JSON brut',
   'message.hideRawJson': 'Masquer le JSON brut',
+  'message.askInChat': 'Demander dans le chat',
 
   'time.yesterday': 'Hier',
   'time.today': "Aujourd'hui",
@@ -477,6 +479,7 @@ const es: Record<keyof typeof en, string> = {
   'message.metadata': 'Detalles del mensaje',
   'message.rawJson': 'JSON sin formato',
   'message.hideRawJson': 'Ocultar JSON sin formato',
+  'message.askInChat': 'Preguntar en el chat',
 
   'time.yesterday': 'Ayer',
   'time.today': 'Hoy',
@@ -661,6 +664,7 @@ const de: Record<keyof typeof en, string> = {
   'message.metadata': 'Nachrichtendetails',
   'message.rawJson': 'Roh-JSON',
   'message.hideRawJson': 'Roh-JSON ausblenden',
+  'message.askInChat': 'Im Chat fragen',
 
   'time.yesterday': 'Gestern',
   'time.today': 'Heute',
@@ -843,6 +847,7 @@ const ja: Record<keyof typeof en, string> = {
   'message.metadata': 'メッセージの詳細',
   'message.rawJson': '生JSON',
   'message.hideRawJson': '生JSONを非表示',
+  'message.askInChat': 'チャットで質問',
 
   'time.yesterday': '昨日',
   'time.today': '今日',
@@ -1025,6 +1030,7 @@ const pt: Record<keyof typeof en, string> = {
   'message.metadata': 'Detalhes da mensagem',
   'message.rawJson': 'JSON bruto',
   'message.hideRawJson': 'Ocultar JSON bruto',
+  'message.askInChat': 'Perguntar no chat',
 
   'time.yesterday': 'Ontem',
   'time.today': 'Hoje',
@@ -1207,6 +1213,7 @@ const zh: Record<keyof typeof en, string> = {
   'message.metadata': '消息详情',
   'message.rawJson': '原始 JSON',
   'message.hideRawJson': '隐藏原始 JSON',
+  'message.askInChat': '在聊天中提问',
 
   'time.yesterday': '昨天',
   'time.today': '今天',
@@ -1389,6 +1396,7 @@ const it: Record<keyof typeof en, string> = {
   'message.metadata': 'Dettagli messaggio',
   'message.rawJson': 'JSON grezzo',
   'message.hideRawJson': 'Nascondi JSON grezzo',
+  'message.askInChat': 'Chiedi in chat',
 
   'time.yesterday': 'Ieri',
   'time.today': 'Oggi',