tyulyukov · tyulyukov · Apr 9, 2026 · Apr 9, 2026 · Apr 9, 2026 · Apr 9, 2026
diff --git a/AGENTS.md b/AGENTS.md
@@ -246,3 +246,25 @@ Board selection stored per project via `jiraBoard` field on `OrchestrationProjec
 - `ComposerPromptSegment` union includes `"jira-context"` type alongside `"terminal-context"`
 - `ComposerCommandItem` union includes `"jira-task"` type for menu autocomplete
 - `Project` type in `types.ts` includes `jiraBoard: JiraBoardReference | null`
+
+## Reply to Selection (Quoted Context)
+
+MarCode supports replying to specific text selections within assistant messages. Users can select text in an agent response, click "Reply" in a floating toolbar, and the selected text is quoted as structured context in the composer.
+
+### Architecture
+
+- **`apps/web/src/lib/quotedContext.ts`** — `QuotedContext` type, prompt assembly (`appendQuotedContextsToPrompt`), extraction (`extractLeadingQuotedContexts`), dedup, truncation (5000 char limit).
+- **`apps/web/src/components/chat/SelectionReplyToolbar.tsx`** — Floating toolbar that appears on text selection within assistant messages. Renders via `createPortal` to `document.body`. Detects code block selections and extracts language.
+- **`apps/web/src/components/chat/QuotedContextInlineChip.tsx`** — Visual chip rendered in the composer above the editor showing quoted text preview with remove button. Uses violet color scheme.
+- **`apps/web/src/components/chat/UserMessageQuotedContextLabel.tsx`** — Expandable label in the message timeline showing quoted context when a sent message includes it.
+- **`apps/web/src/components/chat/MessagesTimeline.tsx`** — `AssistantMessageContentWithReply` wraps assistant message content with a ref for selection tracking and renders `SelectionReplyToolbar`.
+
+### Key Patterns
+
+- `QuotedContext` is stored in `composerDraftStore` as `quotedContexts: QuotedContext[]` on `ComposerThreadDraftState`.
+- Quoted context blocks are **prepended** to the prompt (unlike terminal/jira which are appended) as `<quoted_context message_id="..." language="...">` XML blocks.
+- `extractLeadingQuotedContexts()` parses leading quoted blocks from stored message text for timeline display.
+- Keyboard shortcut: `Cmd/Ctrl+Shift+R` to reply to current selection, `Escape` to dismiss toolbar.
+- Quoted contexts are **not** persisted to localStorage (transient draft state) — they are cleared on thread switch or send.
+- Selection spanning multiple messages captures only text from the message where selection started.
+- Truncation at 5000 chars with `...[truncated]` suffix.
diff --git a/apps/web/src/components/ChatView.logic.ts b/apps/web/src/components/ChatView.logic.ts
@@ -174,6 +174,7 @@ export function deriveComposerSendState(options: {
   imageCount: number;
   terminalContexts: ReadonlyArray<TerminalContextDraft>;
   jiraTaskContexts?: ReadonlyArray<JiraTaskDraft>;
+  quotedContextCount?: number;
 }): {
   trimmedPrompt: string;
   sendableTerminalContexts: TerminalContextDraft[];
@@ -187,6 +188,7 @@ export function deriveComposerSendState(options: {
   const expiredTerminalContextCount =
     options.terminalContexts.length - sendableTerminalContexts.length;
   const jiraTaskContexts = options.jiraTaskContexts ?? [];
+  const quotedContextCount = options.quotedContextCount ?? 0;
   return {
     trimmedPrompt,
     sendableTerminalContexts,
@@ -195,7 +197,8 @@ export function deriveComposerSendState(options: {
       trimmedPrompt.length > 0 ||
       options.imageCount > 0 ||
       sendableTerminalContexts.length > 0 ||
-      jiraTaskContexts.length > 0,
+      jiraTaskContexts.length > 0 ||
+      quotedContextCount > 0,
   };
 }
 

diff --git a/apps/web/src/components/ChatView.tsx b/apps/web/src/components/ChatView.tsx
@@ -168,6 +168,13 @@ import {
   parseJiraUrl,
   removeInlineJiraContextPlaceholder,
 } from "../lib/jiraContext";
+import {
+  appendQuotedContextsToPrompt,
+  formatQuotedContextPreview,
+  formatQuotedContextTooltip,
+  type QuotedContext,
+} from "../lib/quotedContext";
+import { QuotedContextInlineChip } from "./chat/QuotedContextInlineChip";
 import {
   jiraConnectionStatusQueryOptions,
   jiraIssueSearchQueryOptions,
@@ -409,6 +416,7 @@ interface SubmitComposerTurnInput {
   images: ComposerImageAttachment[];
   terminalContexts: TerminalContextDraft[];
   jiraTaskContexts: JiraTaskDraft[];
+  quotedContexts: QuotedContext[];
   expiredTerminalContextCount: number;
   clearComposerDraft: boolean;
 }
@@ -684,15 +692,23 @@ export default function ChatView({ threadId }: ChatViewProps) {
   const composerImages = composerDraft.images;
   const composerTerminalContexts = composerDraft.terminalContexts;
   const composerJiraTaskContexts = composerDraft.jiraTaskContexts;
+  const composerQuotedContexts = composerDraft.quotedContexts;
   const composerSendState = useMemo(
     () =>
       deriveComposerSendState({
         prompt,
         imageCount: composerImages.length,
         terminalContexts: composerTerminalContexts,
         jiraTaskContexts: composerJiraTaskContexts,
+        quotedContextCount: composerQuotedContexts.length,
       }),
-    [composerImages.length, composerTerminalContexts, composerJiraTaskContexts, prompt],
+    [
+      composerImages.length,
+      composerTerminalContexts,
+      composerJiraTaskContexts,
+      composerQuotedContexts.length,
+      prompt,
+    ],
   );
   const nonPersistedComposerImageIds = composerDraft.nonPersistedImageIds;
   const setComposerDraftPrompt = useComposerDraftStore((store) => store.setPrompt);
@@ -719,9 +735,13 @@ export default function ChatView({ threadId }: ChatViewProps) {
   const addComposerDraftJiraTaskContext = useComposerDraftStore(
     (store) => store.addJiraTaskContext,
   );
+  const addComposerDraftQuotedContext = useComposerDraftStore((store) => store.addQuotedContext);
   const removeComposerDraftJiraTaskContext = useComposerDraftStore(
     (store) => store.removeJiraTaskContext,
   );
+  const removeComposerDraftQuotedContext = useComposerDraftStore(
+    (store) => store.removeQuotedContext,
+  );
   const clearComposerDraftPersistedAttachments = useComposerDraftStore(
     (store) => store.clearPersistedAttachments,
   );
@@ -3134,14 +3154,19 @@ export default function ChatView({ threadId }: ChatViewProps) {
       const composerImagesSnapshot = [...input.images];
       const composerTerminalContextsSnapshot = [...input.terminalContexts];
       const composerJiraTaskContextsSnapshot = [...input.jiraTaskContexts];
+      const composerQuotedContextsSnapshot = [...input.quotedContexts];
       const cleanedPromptForSend = replaceInlineJiraPlaceholdersWithLabels(
         input.prompt,
         composerJiraTaskContextsSnapshot,
       );
-      const messageTextForSend = appendJiraContextsToPrompt(
+      const withTerminalAndJira = appendJiraContextsToPrompt(
         appendTerminalContextsToPrompt(cleanedPromptForSend, composerTerminalContextsSnapshot),
         composerJiraTaskContextsSnapshot,
       );
+      const messageTextForSend = appendQuotedContextsToPrompt(
+        withTerminalAndJira,
+        composerQuotedContextsSnapshot,
+      );
       const messageIdForSend = newMessageId();
       const messageCreatedAt = new Date().toISOString();
       const outgoingMessageText = formatOutgoingPrompt({
@@ -3457,6 +3482,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       imageCount: composerImages.length,
       terminalContexts: composerTerminalContexts,
       jiraTaskContexts: composerJiraTaskContexts,
+      quotedContextCount: composerQuotedContexts.length,
     });
     if (showPlanFollowUpPrompt && activeProposedPlan) {
       const followUp = resolvePlanFollowUpSubmission({
@@ -3509,6 +3535,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       images: [...composerImages],
       terminalContexts: [...sendableComposerTerminalContexts],
       jiraTaskContexts: [...composerJiraTaskContexts],
+      quotedContexts: [...composerQuotedContexts],
       expiredTerminalContextCount,
       clearComposerDraft: true,
     });
@@ -4304,6 +4331,14 @@ export default function ChatView({ threadId }: ChatViewProps) {
       [groupId]: !existing[groupId],
     }));
   }, []);
+  const onReplyToSelection = useCallback(
+    (context: QuotedContext) => {
+      if (!activeThread) return;
+      addComposerDraftQuotedContext(activeThread.id, context);
+      focusComposer();
+    },
+    [activeThread, addComposerDraftQuotedContext, focusComposer],
+  );
   const onSubagentSelect = useCallback((taskId: string) => {
     setSelectedSubagentTaskId(taskId);
   }, []);
@@ -4452,6 +4487,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       images: imagesToSend,
       terminalContexts: [],
       jiraTaskContexts: [],
+      quotedContexts: [],
       expiredTerminalContextCount: 0,
       clearComposerDraft: false,
     });
@@ -4627,6 +4663,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
                 onRemoveEditingUserMessageImage={onRemoveEditingUserMessageImage}
                 onCancelEditUserMessage={discardUserMessageEditSession}
                 onSubmitEditUserMessage={onSubmitEditUserMessage}
+                onReplyToSelection={onReplyToSelection}
               />
             </div>
 
@@ -4789,6 +4826,20 @@ export default function ChatView({ threadId }: ChatViewProps) {
                           ))}
                         </div>
                       )}
+                    {!isComposerApprovalState &&
+                      pendingUserInputs.length === 0 &&
+                      composerQuotedContexts.length > 0 && (
+                        <div className="mb-2 flex flex-wrap gap-1">
+                          {composerQuotedContexts.map((ctx) => (
+                            <QuotedContextInlineChip
+                              key={ctx.id}
+                              preview={formatQuotedContextPreview(ctx)}
+                              tooltipText={formatQuotedContextTooltip(ctx)}
+                              onRemove={() => removeComposerDraftQuotedContext(threadId, ctx.id)}
+                            />
+                          ))}
+                        </div>
+                      )}
                     <ComposerPromptEditor
                       ref={composerEditorRef}
                       value={

diff --git a/apps/web/src/components/chat/CompactComposerControlsMenu.browser.tsx b/apps/web/src/components/chat/CompactComposerControlsMenu.browser.tsx
@@ -24,6 +24,7 @@ async function mountMenu(props?: { modelSelection?: ModelSelection; prompt?: str
     persistedAttachments: [],
     terminalContexts: [],
     jiraTaskContexts: [],
+    quotedContexts: [],
     modelSelectionByProvider: {
       [provider]: {
         provider,

diff --git a/apps/web/src/components/chat/MessagesTimeline.test.tsx b/apps/web/src/components/chat/MessagesTimeline.test.tsx
@@ -106,6 +106,7 @@ describe("MessagesTimeline", () => {
         onRemoveEditingUserMessageImage={() => {}}
         onCancelEditUserMessage={() => {}}
         onSubmitEditUserMessage={() => {}}
+        onReplyToSelection={() => {}}
       />,
     );
 
@@ -164,6 +165,7 @@ describe("MessagesTimeline", () => {
         onRemoveEditingUserMessageImage={() => {}}
         onCancelEditUserMessage={() => {}}
         onSubmitEditUserMessage={() => {}}
+        onReplyToSelection={() => {}}
       />,
     );
 

diff --git a/apps/web/src/components/chat/MessagesTimeline.tsx b/apps/web/src/components/chat/MessagesTimeline.tsx
@@ -69,6 +69,13 @@
 import { cn } from "~/lib/utils";
 import { extractTrailingJiraContexts, type ParsedJiraContextEntry } from "~/lib/jiraContext";
 import { JiraTaskInlineChip } from "./JiraTaskInlineChip";
+import { SelectionReplyToolbar } from "./SelectionReplyToolbar";
+import {
+  extractLeadingQuotedContexts,
+  type ParsedQuotedContextEntry,
+  type QuotedContext,
+} from "~/lib/quotedContext";
+import { UserMessageQuotedContextLabel } from "./UserMessageQuotedContextLabel";
 import { type TimestampFormat } from "@marcode/contracts/settings";
 import { formatTimestamp } from "../../timestampFormat";
 import {
@@ -115,6 +122,7 @@
   onRemoveEditingUserMessageImage: (imageId: string) => void;
   onCancelEditUserMessage: () => void;
   onSubmitEditUserMessage: () => void | Promise<void>;
+  onReplyToSelection: (context: QuotedContext) => void;
   onVirtualizerSnapshot?: (snapshot: {
     totalSize: number;
     measurements: ReadonlyArray<{
@@ -163,6 +171,7 @@
   onRemoveEditingUserMessageImage,
   onCancelEditUserMessage,
   onSubmitEditUserMessage,
+  onReplyToSelection,
   onVirtualizerSnapshot,
 }: MessagesTimelineProps) {
   const timelineRootRef = useRef<HTMLDivElement | null>(null);
@@ -463,11 +472,17 @@
                 </div>
               )}
               <div className="group/msg min-w-0 px-1 py-0.5">
-                <ChatMarkdown
-                  text={messageText}
-                  cwd={markdownCwd}
-                  isStreaming={Boolean(row.message.streaming)}
-                />
+                <AssistantMessageContentWithReply
+                  messageId={row.message.id}
+                  turnId={row.message.turnId ?? null}
+                  onReplyToSelection={onReplyToSelection}
+                >
+                  <ChatMarkdown
+                    text={messageText}
+                    cwd={markdownCwd}
+                    isStreaming={Boolean(row.message.streaming)}
+                  />
+                </AssistantMessageContentWithReply>
                 {(() => {
                   const turnSummary = turnDiffSummaryByAssistantMessageId.get(row.message.id);
                   if (!turnSummary) return null;
@@ -867,7 +882,10 @@
   }
 
   const userImages = props.message.attachments ?? [];
-  const displayedUserMessage = deriveDisplayedUserMessageState(props.message.text);
+  const quotedExtracted = extractLeadingQuotedContexts(props.message.text);
+  const afterQuotedText =
+    quotedExtracted.contextCount > 0 ? quotedExtracted.promptText : props.message.text;
+  const displayedUserMessage = deriveDisplayedUserMessageState(afterQuotedText);
   const terminalContexts = displayedUserMessage.contexts;
   const jiraExtracted = extractTrailingJiraContexts(displayedUserMessage.visibleText);
   const visibleText =
@@ -917,6 +935,9 @@
             ))}
           </div>
         )}
+        {quotedExtracted.contexts.length > 0 && (
+          <UserMessageQuotedContextLabel contexts={quotedExtracted.contexts} />
+        )}
         {(visibleText.trim().length > 0 || terminalContexts.length > 0) && (
           <UserMessageBody
             text={visibleText}
@@ -1066,6 +1087,27 @@
   );
 });
 
+const AssistantMessageContentWithReply = memo(function AssistantMessageContentWithReply(props: {
+  messageId: MessageId;
+  turnId: TurnId | null;
+  children: ReactNode;
+  onReplyToSelection: (context: QuotedContext) => void;
+}) {
+  const containerRef = useRef<HTMLDivElement | null>(null);
+
+  return (
+    <div ref={containerRef} className="relative">
+      {props.children}
+      <SelectionReplyToolbar
+        messageId={props.messageId}
+        turnId={props.turnId}
+        containerRef={containerRef}
+        onReply={props.onReplyToSelection}
+      />
+    </div>
+  );
+});
+
 function workToneIcon(tone: TimelineWorkEntry["tone"]): {
   icon: LucideIcon;
   className: string;

diff --git a/apps/web/src/components/chat/MessagesTimeline.virtualization.browser.tsx b/apps/web/src/components/chat/MessagesTimeline.virtualization.browser.tsx
@@ -182,6 +182,7 @@ function createBaseTimelineProps(input: {
     onRemoveEditingUserMessageImage: () => {},
     onCancelEditUserMessage: () => {},
     onSubmitEditUserMessage: () => {},
+    onReplyToSelection: () => {},
     ...(input.onVirtualizerSnapshot ? { onVirtualizerSnapshot: input.onVirtualizerSnapshot } : {}),
   };
 }

diff --git a/apps/web/src/components/chat/QuotedContextInlineChip.tsx b/apps/web/src/components/chat/QuotedContextInlineChip.tsx
@@ -0,0 +1,56 @@
+import { QuoteIcon, XIcon } from "lucide-react";
+
+import { cn } from "~/lib/utils";
+import {
+  COMPOSER_INLINE_CHIP_CLASS_NAME,
+  COMPOSER_INLINE_CHIP_ICON_CLASS_NAME,
+  COMPOSER_INLINE_CHIP_LABEL_CLASS_NAME,
+  COMPOSER_INLINE_CHIP_DISMISS_BUTTON_CLASS_NAME,
+} from "../composerInlineChip";
+import { Tooltip, TooltipPopup, TooltipTrigger } from "../ui/tooltip";
+
+interface QuotedContextInlineChipProps {
+  preview: string;
+  tooltipText: string;
+  onRemove?: () => void;
+}
+
+export function QuotedContextInlineChip(props: QuotedContextInlineChipProps) {
+  const { preview, tooltipText, onRemove } = props;
+
+  return (
+    <Tooltip>
+      <TooltipTrigger
+        render={
+          <span
+            className={cn(
+              COMPOSER_INLINE_CHIP_CLASS_NAME,
+              "border-violet-500/30 bg-violet-500/12 text-violet-300 dark:border-violet-400/25 dark:bg-violet-400/10 dark:text-violet-300",
+            )}
+          >
+            <QuoteIcon className={cn(COMPOSER_INLINE_CHIP_ICON_CLASS_NAME, "size-3.5")} />
+            <span className={cn(COMPOSER_INLINE_CHIP_LABEL_CLASS_NAME, "max-w-[200px]")}>
+              {preview}
+            </span>
+            {onRemove && (
+              <button
+                type="button"
+                className={COMPOSER_INLINE_CHIP_DISMISS_BUTTON_CLASS_NAME}
+                onClick={(e) => {
+                  e.stopPropagation();
+                  onRemove();
+                }}
+                aria-label="Remove quoted context"
+              >
+                <XIcon className="size-2.5" />
+              </button>
+            )}
+          </span>
+        }
+      />
+      <TooltipPopup side="top" className="max-w-80 whitespace-pre-wrap leading-tight">
+        {tooltipText}
+      </TooltipPopup>
+    </Tooltip>
+  );
+}