feat(agent): 支持持久化 /btw 旁路提问

web/src/app/(main)/chat/page.tsx

@@ -21,6 +21,7 @@ import {
 } from "lucide-react";
 import { toast } from "sonner";
 
+import { SideQuestionButton, SideQuestionWorkspace } from "@/components/side-question-workspace";
 import { TodoPopover } from "@/components/todo-popover";
 import { Transcript } from "@/components/transcript";
 import {
@@ -48,8 +49,10 @@ import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover
 import { ScrollArea } from "@/components/ui/scroll-area";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import { Textarea } from "@/components/ui/textarea";
+import { useSideQuestions } from "@/hooks/use-side-questions";
 import { api } from "@/lib/api";
 import { shouldSubmitOnKey, useChatSendMode } from "@/lib/chat-send-mode";
+import { isBtwCommand } from "@/lib/side-questions";
 import type { Activity, Agent, ChatAttachment, Conversation, LLMProfile } from "@/lib/types";
 import { cn } from "@/lib/utils";
 
@@ -114,6 +117,7 @@ function Composer({
   onPickFiles,
   onRemoveAttachment,
   uploading,
+  allowBtw,
 }: {
   value: string;
   onChange: (v: string) => void;
@@ -129,6 +133,7 @@ function Composer({
   onPickFiles?: (files: FileList | null) => void;
   onRemoveAttachment?: (path: string) => void;
   uploading?: boolean;
+  allowBtw?: boolean;
 }) {
   const fileInputRef = React.useRef<HTMLInputElement>(null);
   const atts = attachments ?? [];
@@ -196,10 +201,15 @@ function Composer({
           rows={1}
           placeholder={placeholder}
           value={value}
-          disabled={disabled}
+          disabled={disabled && !allowBtw}
           onChange={(e) => onChange(e.target.value)}
           onKeyDown={onKeyDown}
         />
+        {running && allowBtw && isBtwCommand(value) && (
+          <Button size="icon" onClick={onSend} aria-label="发送旁路问题" title="发送旁路问题">
+            <ArrowUpIcon />
+          </Button>
+        )}
         {running ? (
           // while a run is in flight the send button becomes a stop button —
           // aborts just this session (the trigger queue keeps going).
@@ -451,6 +461,7 @@ function ChatView({
   const [hasMore, setHasMore] = React.useState(false); // drives the "load earlier" hint
   const agent = agents.find((a) => a.key === conv.agent_key);
   const currentProfileId = conv.llm_profile_id ?? null;
+  const side = useSideQuestions(`/api/conversations/${conv.id}`);
 
   async function changeProfile(id: number | null) {
     try {
@@ -641,6 +652,7 @@ function ChatView({
   async function send() {
     const msg = input.trim();
     const atts = attachments;
+    if (side.handleCommand(msg, () => setInput(""))) return;
     if ((!msg && atts.length === 0) || sending || running) return;
     setSending(true);
     setInput("");
@@ -677,7 +689,7 @@ function ChatView({
   }
 
   return (
-    <>
+    <SideQuestionWorkspace side={side} label={agent?.name ?? conv.agent_key}>
       {/* header: which agent + live + token meta */}
       <div className="flex min-w-0 flex-wrap items-center gap-2 border-b px-4 py-2.5">
         <Bot className="text-muted-foreground size-4 shrink-0" />
@@ -692,6 +704,7 @@ function ChatView({
           <span className="text-muted-foreground min-w-0 truncate text-xs">{agent.description}</span>
         )}
         {running && <LiveBadge />}
+        <SideQuestionButton side={side} />
         <div className="text-muted-foreground ml-auto flex min-w-0 max-w-full items-center justify-end gap-x-3 gap-y-1 text-xs max-sm:w-full max-sm:flex-wrap">
           {tokenTotal.turns > 0 && (
             <span title="agent 循环轮次（模型调用次数）" className="tabular-nums">
@@ -729,7 +742,8 @@ function ChatView({
         onChange={setInput}
         onSend={send}
         disabled={running}
-        placeholder={running ? "Agent 正在回复…" : "输入消息，Enter 发送，Shift+Enter 换行"}
+        allowBtw
+        placeholder={running ? "Agent 正在回复，可输入 /btw 提问…" : "输入消息，Enter 发送，Shift+Enter 换行"}
         running={running}
         onStop={stop}
         stopDisabled={stopping}
@@ -745,7 +759,7 @@ function ChatView({
         disabled={running || sending}
         rightSlot={<TodoPopover seq={latestTodoSeq} fetchDetail={fetchDetail} />}
       />
-    </>
+    </SideQuestionWorkspace>
   );
 }
 

web/src/app/(main)/function/tasks/detail/_tabs/sessions-tab.tsx

@@ -26,6 +26,7 @@ import {
 } from "lucide-react";
 import { toast } from "sonner";
 
+import { SideQuestionButton, SideQuestionWorkspace } from "@/components/side-question-workspace";
 import { TodoPopover } from "@/components/todo-popover";
 import { Transcript } from "@/components/transcript";
 import {
@@ -45,9 +46,11 @@ import { ScrollArea } from "@/components/ui/scroll-area";
 import { Spinner } from "@/components/ui/spinner";
 import { Textarea } from "@/components/ui/textarea";
 import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@/components/ui/tooltip";
+import { useSideQuestions } from "@/hooks/use-side-questions";
 import { api, sseUrl } from "@/lib/api";
 import { shouldSubmitOnKey, useChatSendMode } from "@/lib/chat-send-mode";
 import { MOCK } from "@/lib/mock/enabled";
+import { isBtwCommand } from "@/lib/side-questions";
 import { taskAssetSourceLabel, taskAssetTypeLabel } from "@/lib/task-assets";
 import type {
   Activity,
@@ -1118,6 +1121,13 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   };
 
   const active = sessions.find((s) => s.id === activeId) ?? MAIN_SESSION;
+  const side = useSideQuestions(
+    active.role === "mainagent"
+      ? `/api/tasks/${taskId}/chat`
+      : active.role === "worker" && !active.inherited && active.intent_id
+        ? `/api/tasks/${taskId}/intents/${active.intent_id}`
+        : null,
+  );
   const isMain = active.role === "mainagent";
   const isPlanner = active.role === "planner";
   const isSystem = active.role === "system";
@@ -1310,7 +1320,8 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   function send() {
     const text = input.trim();
     const atts = attachments;
-    if ((!text && atts.length === 0) || sending) return;
+    if (side.handleCommand(text, () => setInput(""))) return;
+    if ((!text && atts.length === 0) || sending || mainLive) return;
     // No optimistic echo: the backend persists+broadcasts the human turn before it
     // returns, so it streams back over SSE (worker="mainagent") with its real DB
     // seq — the transcript renders it from server data like every other step. Clear
@@ -1336,6 +1347,7 @@ export function SessionsTab({ taskId }: { taskId: string }) {
   function sendWorkerChat() {
     const intentId = active.intent_id;
     const message = workerMessage.trim();
+    if (side.handleCommand(message, () => setWorkerMessage(""))) return;
     if (!intentId || active.inherited || active.status !== "paused" || workerMessageSending || !message) return;
     if (workerMessageCharCount(message) > MAX_WORKER_MESSAGE_CHARS) {
       toast.error(`消息不能超过 ${MAX_WORKER_MESSAGE_CHARS} 个字符`);
@@ -1527,332 +1539,356 @@ export function SessionsTab({ taskId }: { taskId: string }) {
         </div>
 
         {/* Right: transcript */}
-        <div className="flex min-w-0 flex-col overflow-hidden rounded-lg border bg-card">
-          <div className="flex min-w-0 flex-wrap items-center gap-x-2 gap-y-1 border-b px-3 py-2 sm:px-4 sm:py-2.5">
-            {(() => {
-              const isWorker = active.role === "worker";
-              const meta = isWorker ? sessionMeta.get(active.id) : undefined;
-              // Worker: the intent moved into the transcript as a message, so the
-              // header shows a stable generic label (intent JSON stays on hover).
-              const title = isWorker ? "Worker 执行会话" : active.title;
-              const titleEl = <span className="min-w-0 truncate text-sm font-medium">{title}</span>;
-              return meta?.json ? (
+        <SideQuestionWorkspace
+          side={side}
+          label={active.role === "worker" ? `Worker #${active.intent_id} · ${activeDisplayTitle}` : activeDisplayTitle}
+        >
+          <div className="flex min-h-0 flex-1 min-w-0 flex-col overflow-hidden rounded-lg border bg-card">
+            <div className="flex min-w-0 flex-wrap items-center gap-x-2 gap-y-1 border-b px-3 py-2 sm:px-4 sm:py-2.5">
+              {(() => {
+                const isWorker = active.role === "worker";
+                const meta = isWorker ? sessionMeta.get(active.id) : undefined;
+                // Worker: the intent moved into the transcript as a message, so the
+                // header shows a stable generic label (intent JSON stays on hover).
+                const title = isWorker ? "Worker 执行会话" : active.title;
+                const titleEl = <span className="min-w-0 truncate text-sm font-medium">{title}</span>;
+                return meta?.json ? (
+                  <Tooltip>
+                    <TooltipTrigger asChild>{titleEl}</TooltipTrigger>
+                    <TooltipContent side="bottom" align="start" className="max-h-80 max-w-sm overflow-auto p-0">
+                      <pre className="p-2 text-[10px] leading-relaxed">{JSON.stringify(meta.json, null, 2)}</pre>
+                    </TooltipContent>
+                  </Tooltip>
+                ) : (
+                  titleEl
+                );
+              })()}
+              <SideQuestionButton side={side} />
+              {activeResolution && (
                 <Tooltip>
-                  <TooltipTrigger asChild>{titleEl}</TooltipTrigger>
-                  <TooltipContent side="bottom" align="start" className="max-h-80 max-w-sm overflow-auto p-0">
-                    <pre className="p-2 text-[10px] leading-relaxed">{JSON.stringify(meta.json, null, 2)}</pre>
-                  </TooltipContent>
-                </Tooltip>
-              ) : (
-                titleEl
-              );
-            })()}
-            {activeResolution && (
-              <Tooltip>
-                <TooltipTrigger asChild>
-                  <Badge
-                    variant="outline"
-                    className="max-w-28 shrink-0 font-normal"
-                    aria-label={
-                      activeResolution.available ? `当前配置：${resolutionLabel(activeResolution)}` : "模型不可用"
-                    }
-                  >
-                    <span className="truncate">
-                      {activeResolution.available ? resolutionLabel(activeResolution) : "模型不可用"}
-                    </span>
-                  </Badge>
-                </TooltipTrigger>
-                <TooltipContent side="bottom" className="max-w-xs [overflow-wrap:anywhere]">
-                  {activeResolution.available
-                    ? [resolutionLabel(activeResolution), activeResolution.model].filter(Boolean).join(" / ")
-                    : activeResolution.reason || "没有可用的 LLM 配置"}
-                </TooltipContent>
-              </Tooltip>
-            )}
-            {activeAssets && activeAssets.length > 0 && <WorkerAssetBadge assets={activeAssets} />}
-            {active.inherited && active.source_task_id && (
-              <Badge variant="outline">来源任务 #{active.source_task_id} · 只读历史</Badge>
-            )}
-            {active.live && (
-              <span className="inline-flex items-center gap-1 rounded bg-blue-500/15 px-1.5 py-0.5 text-[10px] font-medium text-blue-600 dark:text-blue-400">
-                <span className="size-1 animate-pulse rounded-full bg-blue-500" />
-                实时
-              </span>
-            )}
-            {activeState?.hasMore && (
-              <span className="text-[10px] text-muted-foreground" title="向上滚动加载更早历史">
-                ↑ 更早历史
-              </span>
-            )}
-            <div className="ml-auto flex min-w-0 max-w-full items-center justify-end gap-x-3 gap-y-1 text-xs text-muted-foreground max-sm:w-full max-sm:flex-wrap">
-              {tokenTotal.any && (
-                <Tooltip>
-                  {/* 手机端用短标签（入/缓/出）：长标签会把这一行撑成两行，进一步压缩记录区。 */}
                   <TooltipTrigger asChild>
-                    <span className="inline-flex min-w-0 items-center">
-                      <TokenMetrics
-                        input={tokenTotal.i}
-                        cache={tokenTotal.cr}
-                        output={tokenTotal.o}
-                        labels="short"
-                        className="sm:hidden"
-                      />
-                      <TokenMetrics
-                        input={tokenTotal.i}
-                        cache={tokenTotal.cr}
-                        output={tokenTotal.o}
-                        labels="long"
-                        className="max-sm:hidden"
-                      />
-                    </span>
+                    <Badge
+                      variant="outline"
+                      className="max-w-28 shrink-0 font-normal"
+                      aria-label={
+                        activeResolution.available ? `当前配置：${resolutionLabel(activeResolution)}` : "模型不可用"
+                      }
+                    >
+                      <span className="truncate">
+                        {activeResolution.available ? resolutionLabel(activeResolution) : "模型不可用"}
+                      </span>
+                    </Badge>
                   </TooltipTrigger>
-                  <TooltipContent>
-                    输入 {activeTokens.input_tokens.toLocaleString()} · 输出{" "}
-                    {activeTokens.output_tokens.toLocaleString()} · 缓存读取{" "}
-                    {activeTokens.cache_read_tokens.toLocaleString()} · 缓存写入{" "}
-                    {activeTokens.cache_write_tokens.toLocaleString()}
+                  <TooltipContent side="bottom" className="max-w-xs [overflow-wrap:anywhere]">
+                    {activeResolution.available
+                      ? [resolutionLabel(activeResolution), activeResolution.model].filter(Boolean).join(" / ")
+                      : activeResolution.reason || "没有可用的 LLM 配置"}
                   </TooltipContent>
                 </Tooltip>
               )}
-              {runDuration != null && (
-                <span className="inline-flex items-center gap-1" title="运行时长（首步 → 末步）">
-                  <ClockIcon className="size-3" />
-                  {fmtDuration(runDuration)}
+              {activeAssets && activeAssets.length > 0 && <WorkerAssetBadge assets={activeAssets} />}
+              {active.inherited && active.source_task_id && (
+                <Badge variant="outline">来源任务 #{active.source_task_id} · 只读历史</Badge>
+              )}
+              {active.live && (
+                <span className="inline-flex items-center gap-1 rounded bg-blue-500/15 px-1.5 py-0.5 text-[10px] font-medium text-blue-600 dark:text-blue-400">
+                  <span className="size-1 animate-pulse rounded-full bg-blue-500" />
+                  实时
                 </span>
               )}
-              {isMain && <span>可交互</span>}
-            </div>
-          </div>
-          {(() => {
-            const dm = active.role === "worker" ? sessionMeta.get(active.id) : undefined;
-            if (!dm?.deleted) return null;
-            return (
-              <div className="flex items-start gap-2 border-b border-destructive/30 bg-destructive/5 px-4 py-2.5 text-xs">
-                <Trash2Icon className="mt-0.5 size-3.5 shrink-0 text-destructive" />
-                <div className="min-w-0">
-                  <span className="font-medium text-destructive">此意图已被用户删除</span>
-                  <span className="text-muted-foreground">
-                    （已停止执行，规划者已收到通知；意图与产出保留，可在下方查看历史）
+              {activeState?.hasMore && (
+                <span className="text-[10px] text-muted-foreground" title="向上滚动加载更早历史">
+                  ↑ 更早历史
+                </span>
+              )}
+              <div className="ml-auto flex min-w-0 max-w-full items-center justify-end gap-x-3 gap-y-1 text-xs text-muted-foreground max-sm:w-full max-sm:flex-wrap">
+                {tokenTotal.any && (
+                  <Tooltip>
+                    {/* 手机端用短标签（入/缓/出）：长标签会把这一行撑成两行，进一步压缩记录区。 */}
+                    <TooltipTrigger asChild>
+                      <span className="inline-flex min-w-0 items-center">
+                        <TokenMetrics
+                          input={tokenTotal.i}
+                          cache={tokenTotal.cr}
+                          output={tokenTotal.o}
+                          labels="short"
+                          className="sm:hidden"
+                        />
+                        <TokenMetrics
+                          input={tokenTotal.i}
+                          cache={tokenTotal.cr}
+                          output={tokenTotal.o}
+                          labels="long"
+                          className="max-sm:hidden"
+                        />
+                      </span>
+                    </TooltipTrigger>
+                    <TooltipContent>
+                      输入 {activeTokens.input_tokens.toLocaleString()} · 输出{" "}
+                      {activeTokens.output_tokens.toLocaleString()} · 缓存读取{" "}
+                      {activeTokens.cache_read_tokens.toLocaleString()} · 缓存写入{" "}
+                      {activeTokens.cache_write_tokens.toLocaleString()}
+                    </TooltipContent>
+                  </Tooltip>
+                )}
+                {runDuration != null && (
+                  <span className="inline-flex items-center gap-1" title="运行时长（首步 → 末步）">
+                    <ClockIcon className="size-3" />
+                    {fmtDuration(runDuration)}
                   </span>
-                  {dm.deleteReason && (
-                    <p className="mt-1 break-words text-foreground">
-                      <span className="text-muted-foreground">删除原因：</span>
-                      {dm.deleteReason}
-                    </p>
-                  )}
-                </div>
+                )}
+                {isMain && <span>可交互</span>}
               </div>
-            );
-          })()}
-          {/* Force Radix's internal viewport wrapper (display:table, sizes to content)
+            </div>
+            {(() => {
+              const dm = active.role === "worker" ? sessionMeta.get(active.id) : undefined;
+              if (!dm?.deleted) return null;
+              return (
+                <div className="flex items-start gap-2 border-b border-destructive/30 bg-destructive/5 px-4 py-2.5 text-xs">
+                  <Trash2Icon className="mt-0.5 size-3.5 shrink-0 text-destructive" />
+                  <div className="min-w-0">
+                    <span className="font-medium text-destructive">此意图已被用户删除</span>
+                    <span className="text-muted-foreground">
+                      （已停止执行，规划者已收到通知；意图与产出保留，可在下方查看历史）
+                    </span>
+                    {dm.deleteReason && (
+                      <p className="mt-1 break-words text-foreground">
+                        <span className="text-muted-foreground">删除原因：</span>
+                        {dm.deleteReason}
+                      </p>
+                    )}
+                  </div>
+                </div>
+              );
+            })()}
+            {/* Force Radix's internal viewport wrapper (display:table, sizes to content)
             to block so wide/unbreakable steps (long commands, code, URLs) can't blow
             out the width and defeat the truncation below — the transcript wraps to
             the panel instead of overflowing horizontally. */}
-          <ScrollArea type="auto" className="min-h-0 min-w-0 flex-1 [&_[data-slot=scroll-area-viewport]>div]:block!">
-            <div className="min-w-0 max-w-full p-4" ref={contentRef}>
-              {activeState?.loadingMore && (
-                <div className="flex items-center justify-center gap-2 pb-2 text-xs text-muted-foreground">
-                  <Loader2Icon className="size-3.5 animate-spin" />
-                  加载更早历史…
-                </div>
-              )}
-              {showLoader ? (
-                <div className="flex items-center gap-2 pl-9 text-xs text-muted-foreground">
-                  <Loader2Icon className="size-3.5 animate-spin" />
-                  加载活动流…
-                </div>
-              ) : activeState?.error ? (
-                <div className="flex items-center gap-2 pl-9 text-xs text-red-500">
-                  <CircleXIcon className="size-3.5" />
-                  加载失败：{activeState.error}
-                  <Button size="sm" variant="ghost" className="h-6 px-2 text-xs" onClick={() => loadSession(activeKey)}>
-                    重试
-                  </Button>
-                </div>
-              ) : activity.length ? (
-                <Transcript activity={activity} live={active.live} taskId={taskId} chat={isMain} />
-              ) : (
-                <div className="pl-9 text-xs text-muted-foreground">
-                  {isMain ? "还没有对话。在下方给主 Agent 发消息，引导探索方向或介入流程。" : "暂无活动记录。"}
-                </div>
-              )}
-            </div>
-          </ScrollArea>
-          {isMain ? (
-            <div className="border-t p-3">
-              {attachments.length > 0 && (
-                <div className="mb-2 flex flex-wrap gap-1.5">
-                  {attachments.map((a) => (
-                    <div
-                      key={a.path}
-                      className="flex items-center gap-1.5 rounded-md border bg-muted/50 px-2 py-1 text-xs"
-                      title={a.path}
+            <ScrollArea type="auto" className="min-h-0 min-w-0 flex-1 [&_[data-slot=scroll-area-viewport]>div]:block!">
+              <div className="min-w-0 max-w-full p-4" ref={contentRef}>
+                {activeState?.loadingMore && (
+                  <div className="flex items-center justify-center gap-2 pb-2 text-xs text-muted-foreground">
+                    <Loader2Icon className="size-3.5 animate-spin" />
+                    加载更早历史…
+                  </div>
+                )}
+                {showLoader ? (
+                  <div className="flex items-center gap-2 pl-9 text-xs text-muted-foreground">
+                    <Loader2Icon className="size-3.5 animate-spin" />
+                    加载活动流…
+                  </div>
+                ) : activeState?.error ? (
+                  <div className="flex items-center gap-2 pl-9 text-xs text-red-500">
+                    <CircleXIcon className="size-3.5" />
+                    加载失败：{activeState.error}
+                    <Button
+                      size="sm"
+                      variant="ghost"
+                      className="h-6 px-2 text-xs"
+                      onClick={() => loadSession(activeKey)}
                     >
-                      <PaperclipIcon className="size-3 shrink-0 text-primary" />
-                      <span className="max-w-[160px] truncate">{a.name}</span>
-                      <span className="text-muted-foreground">{fmtBytes(a.size)}</span>
-                      <button
-                        type="button"
-                        className="ml-0.5 text-muted-foreground hover:text-foreground"
-                        onClick={() => setAttachments((p) => p.filter((x) => x.path !== a.path))}
-                        title="移除"
+                      重试
+                    </Button>
+                  </div>
+                ) : activity.length ? (
+                  <Transcript activity={activity} live={active.live} taskId={taskId} chat={isMain} />
+                ) : (
+                  <div className="pl-9 text-xs text-muted-foreground">
+                    {isMain ? "还没有对话。在下方给主 Agent 发消息，引导探索方向或介入流程。" : "暂无活动记录。"}
+                  </div>
+                )}
+              </div>
+            </ScrollArea>
+            {isMain ? (
+              <div className="border-t p-3">
+                {attachments.length > 0 && (
+                  <div className="mb-2 flex flex-wrap gap-1.5">
+                    {attachments.map((a) => (
+                      <div
+                        key={a.path}
+                        className="flex items-center gap-1.5 rounded-md border bg-muted/50 px-2 py-1 text-xs"
+                        title={a.path}
                       >
-                        <XIcon className="size-3" />
-                      </button>
-                    </div>
-                  ))}
-                </div>
-              )}
-              <input
-                ref={fileInputRef}
-                type="file"
-                multiple
-                className="hidden"
-                onChange={(e) => void pickFiles(e.target.files)}
-              />
-              <InputGroup className="min-h-9 has-disabled:opacity-100">
-                <InputGroupTextarea
-                  rows={1}
-                  aria-label="给主 Agent 发消息"
-                  placeholder="给主 Agent 发消息，引导探索方向…"
-                  value={input}
-                  onChange={(e) => setInput(e.target.value)}
-                  onKeyDown={(e) => {
-                    if (!shouldSubmitOnKey(e, sendMode)) return;
-                    e.preventDefault();
-                    if (!mainLive) send();
-                  }}
-                  disabled={mainLive}
-                  className="max-h-36 min-h-9 overflow-y-auto"
+                        <PaperclipIcon className="size-3 shrink-0 text-primary" />
+                        <span className="max-w-[160px] truncate">{a.name}</span>
+                        <span className="text-muted-foreground">{fmtBytes(a.size)}</span>
+                        <button
+                          type="button"
+                          className="ml-0.5 text-muted-foreground hover:text-foreground"
+                          onClick={() => setAttachments((p) => p.filter((x) => x.path !== a.path))}
+                          title="移除"
+                        >
+                          <XIcon className="size-3" />
+                        </button>
+                      </div>
+                    ))}
+                  </div>
+                )}
+                <input
+                  ref={fileInputRef}
+                  type="file"
+                  multiple
+                  className="hidden"
+                  onChange={(e) => void pickFiles(e.target.files)}
                 />
-                <InputGroupAddon align="block-end">
-                  <InputGroupButton
-                    size="icon-xs"
-                    variant="ghost"
-                    onClick={() => fileInputRef.current?.click()}
-                    disabled={mainLive || uploading}
-                    title="上传文件"
-                    aria-label="上传文件"
-                  >
-                    {uploading ? <Loader2Icon className="animate-spin" /> : <PaperclipIcon />}
-                  </InputGroupButton>
-                  {mainLive ? (
+                <InputGroup className="min-h-9 has-disabled:opacity-100">
+                  <InputGroupTextarea
+                    rows={1}
+                    aria-label="给主 Agent 发消息"
+                    placeholder={mainLive ? "主 Agent 正在运行，可输入 /btw 提问…" : "给主 Agent 发消息，引导探索方向…"}
+                    value={input}
+                    onChange={(e) => setInput(e.target.value)}
+                    onKeyDown={(e) => {
+                      if (!shouldSubmitOnKey(e, sendMode)) return;
+                      e.preventDefault();
+                      send();
+                    }}
+                    className="max-h-36 min-h-9 overflow-y-auto"
+                  />
+                  <InputGroupAddon align="block-end">
                     <InputGroupButton
-                      className="ml-auto"
                       size="icon-xs"
-                      variant="destructive"
-                      onClick={stop}
-                      disabled={stopping}
-                      title="停止当前执行"
-                      aria-label="停止当前执行"
+                      variant="ghost"
+                      onClick={() => fileInputRef.current?.click()}
+                      disabled={mainLive || uploading}
+                      title="上传文件"
+                      aria-label="上传文件"
                     >
-                      {stopping ? <Loader2Icon className="animate-spin" /> : <SquareIcon />}
+                      {uploading ? <Loader2Icon className="animate-spin" /> : <PaperclipIcon />}
                     </InputGroupButton>
-                  ) : (
-                    <InputGroupButton
-                      className="ml-auto"
-                      size="icon-xs"
-                      variant="default"
-                      onClick={send}
-                      disabled={(!input.trim() && attachments.length === 0) || sending}
-                      title="发送消息"
-                      aria-label="发送消息"
-                    >
-                      {sending ? <Loader2Icon className="animate-spin" /> : <ArrowUpIcon />}
-                    </InputGroupButton>
-                  )}
-                </InputGroupAddon>
-              </InputGroup>
-            </div>
-          ) : active.role === "worker" &&
-            !active.inherited &&
-            (active.status === "running" || active.status === "paused") ? (
-            <div className="border-t p-3">
-              <InputGroup className="min-h-9 has-disabled:opacity-100">
-                <InputGroupTextarea
-                  rows={1}
-                  aria-label={`给 Worker #${active.intent_id} 发消息`}
-                  placeholder={`给 Worker #${active.intent_id} 发消息，调整执行方向…`}
-                  value={workerMessage}
-                  onChange={(event) => {
-                    setWorkerMessage(event.target.value);
-                    setWorkerMessageRequestId("");
-                  }}
-                  onKeyDown={(event) => {
-                    if (!shouldSubmitOnKey(event, sendMode)) return;
-                    event.preventDefault();
-                    sendWorkerChat();
-                  }}
-                  disabled={active.status === "running" || workerMessageSending}
-                  aria-invalid={workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS}
-                  className="max-h-36 min-h-9 overflow-y-auto"
-                />
-                <InputGroupAddon align="block-end">
-                  <span
-                    className={cn(
-                      "px-1 text-[10px] tabular-nums text-muted-foreground",
-                      workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS && "text-destructive",
+                    {mainLive && isBtwCommand(input) && (
+                      <InputGroupButton size="icon-xs" onClick={send} aria-label="发送旁路问题">
+                        <ArrowUpIcon />
+                      </InputGroupButton>
                     )}
-                  >
-                    {workerMessageCharCount(workerMessage)}/{MAX_WORKER_MESSAGE_CHARS}
-                  </span>
-                  {active.status === "running" ? (
-                    <InputGroupButton
-                      className="ml-auto"
-                      size="icon-xs"
-                      variant="destructive"
-                      onClick={() => void controlWorker(active, "pause")}
-                      disabled={controllingIntent === active.intent_id}
-                      title="暂停当前 Worker"
-                      aria-label="暂停当前 Worker"
-                    >
-                      {controllingIntent === active.intent_id ? (
-                        <Loader2Icon className="animate-spin" />
-                      ) : (
-                        <SquareIcon />
-                      )}
-                    </InputGroupButton>
-                  ) : (
-                    <>
+                    {mainLive ? (
                       <InputGroupButton
                         className="ml-auto"
-                        size="xs"
-                        variant="ghost"
-                        onClick={() => void controlWorker(active, "resume")}
-                        disabled={controllingIntent === active.intent_id || workerMessageSending}
-                        title="不发消息，直接继续执行"
-                        aria-label="直接继续执行"
+                        size="icon-xs"
+                        variant="destructive"
+                        onClick={stop}
+                        disabled={stopping}
+                        title="停止当前执行"
+                        aria-label="停止当前执行"
                       >
-                        {controllingIntent === active.intent_id ? <Loader2Icon className="animate-spin" /> : "直接继续"}
+                        {stopping ? <Loader2Icon className="animate-spin" /> : <SquareIcon />}
                       </InputGroupButton>
+                    ) : (
                       <InputGroupButton
+                        className="ml-auto"
                         size="icon-xs"
                         variant="default"
-                        onClick={sendWorkerChat}
-                        disabled={
-                          workerMessageSending ||
-                          !workerMessage.trim() ||
-                          workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS
-                        }
+                        onClick={send}
+                        disabled={(!input.trim() && attachments.length === 0) || sending}
                         title="发送消息"
                         aria-label="发送消息"
                       >
-                        {workerMessageSending ? <Spinner /> : <ArrowUpIcon />}
+                        {sending ? <Loader2Icon className="animate-spin" /> : <ArrowUpIcon />}
                       </InputGroupButton>
-                    </>
-                  )}
-                </InputGroupAddon>
-              </InputGroup>
-            </div>
-          ) : (
-            <div className="flex items-center border-t px-4 py-2">
-              <TodoPopover
-                seq={latestTodoSeq}
-                fetchDetail={(seq) => api.activityDetail(seq, taskId).then((r) => r.detail ?? "")}
-              />
-            </div>
-          )}
-        </div>
+                    )}
+                  </InputGroupAddon>
+                </InputGroup>
+              </div>
+            ) : active.role === "worker" &&
+              !active.inherited &&
+              (active.status === "running" || active.status === "paused") ? (
+              <div className="border-t p-3">
+                <InputGroup className="min-h-9 has-disabled:opacity-100">
+                  <InputGroupTextarea
+                    rows={1}
+                    aria-label={`给 Worker #${active.intent_id} 发消息`}
+                    placeholder={`给 Worker #${active.intent_id} 发消息，调整执行方向…`}
+                    value={workerMessage}
+                    onChange={(event) => {
+                      setWorkerMessage(event.target.value);
+                      setWorkerMessageRequestId("");
+                    }}
+                    onKeyDown={(event) => {
+                      if (!shouldSubmitOnKey(event, sendMode)) return;
+                      event.preventDefault();
+                      sendWorkerChat();
+                    }}
+                    disabled={workerMessageSending}
+                    aria-invalid={workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS}
+                    className="max-h-36 min-h-9 overflow-y-auto"
+                  />
+                  <InputGroupAddon align="block-end">
+                    <span
+                      className={cn(
+                        "px-1 text-[10px] tabular-nums text-muted-foreground",
+                        workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS && "text-destructive",
+                      )}
+                    >
+                      {workerMessageCharCount(workerMessage)}/{MAX_WORKER_MESSAGE_CHARS}
+                    </span>
+                    {active.status === "running" && isBtwCommand(workerMessage) && (
+                      <InputGroupButton size="icon-xs" onClick={sendWorkerChat} aria-label="发送旁路问题">
+                        <ArrowUpIcon />
+                      </InputGroupButton>
+                    )}
+                    {active.status === "running" ? (
+                      <InputGroupButton
+                        className="ml-auto"
+                        size="icon-xs"
+                        variant="destructive"
+                        onClick={() => void controlWorker(active, "pause")}
+                        disabled={controllingIntent === active.intent_id}
+                        title="暂停当前 Worker"
+                        aria-label="暂停当前 Worker"
+                      >
+                        {controllingIntent === active.intent_id ? (
+                          <Loader2Icon className="animate-spin" />
+                        ) : (
+                          <SquareIcon />
+                        )}
+                      </InputGroupButton>
+                    ) : (
+                      <>
+                        <InputGroupButton
+                          className="ml-auto"
+                          size="xs"
+                          variant="ghost"
+                          onClick={() => void controlWorker(active, "resume")}
+                          disabled={controllingIntent === active.intent_id || workerMessageSending}
+                          title="不发消息，直接继续执行"
+                          aria-label="直接继续执行"
+                        >
+                          {controllingIntent === active.intent_id ? (
+                            <Loader2Icon className="animate-spin" />
+                          ) : (
+                            "直接继续"
+                          )}
+                        </InputGroupButton>
+                        <InputGroupButton
+                          size="icon-xs"
+                          variant="default"
+                          onClick={sendWorkerChat}
+                          disabled={
+                            workerMessageSending ||
+                            !workerMessage.trim() ||
+                            workerMessageCharCount(workerMessage) > MAX_WORKER_MESSAGE_CHARS
+                          }
+                          title="发送消息"
+                          aria-label="发送消息"
+                        >
+                          {workerMessageSending ? <Spinner /> : <ArrowUpIcon />}
+                        </InputGroupButton>
+                      </>
+                    )}
+                  </InputGroupAddon>
+                </InputGroup>
+              </div>
+            ) : (
+              <div className="flex items-center border-t px-4 py-2">
+                <TodoPopover
+                  seq={latestTodoSeq}
+                  fetchDetail={(seq) => api.activityDetail(seq, taskId).then((r) => r.detail ?? "")}
+                />
+              </div>
+            )}
+          </div>
+        </SideQuestionWorkspace>
         <AlertDialog
           open={cancelIntent !== null}
           onOpenChange={(open) => {

web/src/components/side-question-workspace.tsx

@@ -0,0 +1,231 @@
+"use client";
+
+import { type ReactNode, useEffect, useRef, useState } from "react";
+
+import { ArrowUpIcon, MessageCircleQuestionIcon, SquareIcon, Trash2Icon, XIcon } from "lucide-react";
+
+import { Markdown } from "@/components/markdown";
+import { Alert, AlertDescription } from "@/components/ui/alert";
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog";
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import { Drawer, DrawerContent, DrawerDescription, DrawerHeader, DrawerTitle } from "@/components/ui/drawer";
+import { Empty, EmptyDescription, EmptyHeader, EmptyTitle } from "@/components/ui/empty";
+import { InputGroup, InputGroupAddon, InputGroupButton, InputGroupTextarea } from "@/components/ui/input-group";
+import { ResizableHandle, ResizablePanel, ResizablePanelGroup } from "@/components/ui/resizable";
+import { Skeleton } from "@/components/ui/skeleton";
+import { useIsMobile } from "@/hooks/use-mobile";
+import type { SideQuestions } from "@/hooks/use-side-questions";
+
+export function SideQuestionButton({ side }: { side: SideQuestions }) {
+  if (!side.enabled) return null;
+  return (
+    <Button variant="outline" size="sm" onClick={() => side.setOpen(true)} title="/btw 旁路提问">
+      <MessageCircleQuestionIcon data-icon="inline-start" />
+      旁路提问
+    </Button>
+  );
+}
+
+function SidePanel({ side, label }: { side: SideQuestions; label: string }) {
+  const [confirm, setConfirm] = useState(false);
+  const viewport = useRef<HTMLDivElement>(null);
+  const pinned = useRef(true);
+  const tail = side.items.at(-1);
+  // biome-ignore lint/correctness/useExhaustiveDependencies: New cumulative text scrolls only readers who remain at the bottom.
+  useEffect(() => {
+    if (pinned.current && viewport.current) viewport.current.scrollTop = viewport.current.scrollHeight;
+  }, [tail?.answer, tail?.id]);
+  const status = { running: "回答中", completed: "已完成", failed: "失败", cancelled: "已停止", interrupted: "已中断" };
+  return (
+    <section className="flex h-full min-h-0 flex-col bg-background" aria-label="旁路提问面板">
+      <div className="flex items-center gap-2 border-b p-3">
+        <div className="min-w-0 flex-1">
+          <p className="font-medium">
+            旁路提问 <span className="text-muted-foreground">/btw</span>
+          </p>
+          <p className="truncate text-muted-foreground text-xs">{label}</p>
+        </div>
+        <Button
+          variant="ghost"
+          size="icon-sm"
+          onClick={() => setConfirm(true)}
+          disabled={!side.items.length || side.busy}
+          aria-label="清空旁路历史"
+        >
+          <Trash2Icon />
+        </Button>
+        <Button variant="ghost" size="icon-sm" onClick={() => side.setOpen(false)} aria-label="关闭旁路面板">
+          <XIcon />
+        </Button>
+      </div>
+      <div className="border-b px-3 py-2 text-muted-foreground text-xs">
+        {side.snapshot ? (
+          <>
+            <p>{side.snapshot.model.model}</p>
+            <p>上下文更新于 {new Date(side.snapshot.captured_at).toLocaleString()}</p>
+          </>
+        ) : (
+          "主 Agent 首次运行后即可提问"
+        )}
+      </div>
+      <div
+        ref={viewport}
+        onScroll={(event) => {
+          const el = event.currentTarget;
+          pinned.current = el.scrollHeight - el.scrollTop - el.clientHeight < 80;
+        }}
+        className="min-h-0 flex-1 overflow-y-auto p-3"
+      >
+        {side.nextCursor > 0 && (
+          <Button variant="ghost" size="sm" onClick={() => void side.load(side.nextCursor)}>
+            加载更早的旁路问答
+          </Button>
+        )}
+        {side.loading && <Skeleton className="h-16 w-full" />}
+        {!side.loading && side.items.length === 0 && (
+          <Empty>
+            <EmptyHeader>
+              <EmptyTitle>随时问一个问题</EmptyTitle>
+              <EmptyDescription>根据当前 Agent 的上下文回答，主任务继续运行。</EmptyDescription>
+            </EmptyHeader>
+          </Empty>
+        )}
+        <div className="flex flex-col gap-5">
+          {side.items.map((item) => (
+            <article key={item.id} className="flex min-w-0 flex-col gap-2">
+              <div className="whitespace-pre-wrap break-words rounded-lg bg-muted p-3 text-sm">{item.question}</div>
+              <div className="flex flex-wrap items-center gap-2 text-muted-foreground text-xs">
+                <Badge variant="secondary">{status[item.status]}</Badge>
+                <span className="truncate">{item.model.model}</span>
+                <time dateTime={item.snapshot_at} title={new Date(item.snapshot_at).toLocaleString()}>
+                  上下文 {new Date(item.snapshot_at).toLocaleTimeString()}
+                </time>
+              </div>
+              {item.answer && <Markdown text={item.answer} />}
+              {!item.answer && item.status === "running" && (
+                <p role="status" className="text-muted-foreground text-sm">
+                  正在回答…
+                </p>
+              )}
+              {item.error && (
+                <Alert variant="destructive">
+                  <AlertDescription>{item.error}</AlertDescription>
+                </Alert>
+              )}
+            </article>
+          ))}
+        </div>
+      </div>
+      {(side.error || side.snapshot?.reason) && (
+        <Alert variant="destructive">
+          <AlertDescription>{side.error || side.snapshot?.reason}</AlertDescription>
+        </Alert>
+      )}
+      <div className="border-t p-3">
+        <InputGroup>
+          <InputGroupTextarea
+            aria-label="旁路问题"
+            placeholder="询问当前上下文…"
+            value={side.draft}
+            maxLength={4000}
+            disabled={side.busy}
+            onChange={(event) => side.setDraft(event.target.value)}
+            onKeyDown={(event) => {
+              if (event.key === "Enter" && !event.shiftKey && !event.nativeEvent.isComposing) {
+                event.preventDefault();
+                void side.ask(side.draft);
+              }
+            }}
+          />
+          <InputGroupAddon align="block-end">
+            <span className="text-muted-foreground text-xs">独立问答 · 无工具执行</span>
+            {side.running ? (
+              <InputGroupButton
+                className="ml-auto"
+                variant="destructive"
+                size="icon-xs"
+                onClick={() => void side.stop()}
+                aria-label="停止旁路回答"
+              >
+                <SquareIcon />
+              </InputGroupButton>
+            ) : (
+              <InputGroupButton
+                className="ml-auto"
+                variant="default"
+                size="icon-xs"
+                onClick={() => void side.ask(side.draft)}
+                disabled={side.busy || !side.draft.trim() || !side.snapshot?.available}
+                aria-label="发送旁路问题"
+              >
+                <ArrowUpIcon />
+              </InputGroupButton>
+            )}
+          </InputGroupAddon>
+        </InputGroup>
+      </div>
+      <AlertDialog open={confirm} onOpenChange={setConfirm}>
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>清空旁路历史？</AlertDialogTitle>
+            <AlertDialogDescription>
+              删除当前 Agent 的旁路问答，并停止正在生成的旁路回答。主会话和上下文快照会保留。
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>取消</AlertDialogCancel>
+            <AlertDialogAction onClick={() => void side.clear()}>清空历史</AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </section>
+  );
+}
+
+export function SideQuestionWorkspace({
+  side,
+  label,
+  children,
+}: {
+  side: SideQuestions;
+  label: string;
+  children: ReactNode;
+}) {
+  const mobile = useIsMobile();
+  return (
+    <>
+      <ResizablePanelGroup orientation="horizontal" className="min-h-0 min-w-0 flex-1">
+        <ResizablePanel id="main-conversation" minSize="35%" className="flex min-h-0 min-w-0 flex-col">
+          {children}
+        </ResizablePanel>
+        {side.open && side.enabled && !mobile && (
+          <>
+            <ResizableHandle withHandle />
+            <ResizablePanel id="side-question" defaultSize="38%" minSize="280px" maxSize="65%">
+              <SidePanel side={side} label={label} />
+            </ResizablePanel>
+          </>
+        )}
+      </ResizablePanelGroup>
+      <Drawer open={mobile && side.open && side.enabled} onOpenChange={side.setOpen}>
+        <DrawerContent className="h-[85svh]">
+          <DrawerHeader className="sr-only">
+            <DrawerTitle>旁路提问</DrawerTitle>
+            <DrawerDescription>{label} 的独立问答</DrawerDescription>
+          </DrawerHeader>
+          <SidePanel side={side} label={label} />
+        </DrawerContent>
+      </Drawer>
+    </>
+  );
+}

web/src/hooks/use-side-questions.ts

@@ -0,0 +1,224 @@
+"use client";
+
+import { useCallback, useEffect, useRef, useState } from "react";
+
+import { toast } from "sonner";
+
+import { sseUrl } from "@/lib/api";
+import { isBtwCommand, type SideExchange, type SideHistory, sideAPI } from "@/lib/side-questions";
+
+function merge(old: SideExchange[], incoming: SideExchange[]) {
+  const byID = new Map(old.map((item) => [item.id, item]));
+  for (const item of incoming) {
+    if ((byID.get(item.id)?.sequence ?? -1) <= item.sequence) byID.set(item.id, item);
+  }
+  return [...byID.values()].sort((a, b) => a.ordinal - b.ordinal);
+}
+
+export function useSideQuestions(parent: string | null) {
+  const [stateParent, setStateParent] = useState(parent);
+  const current = stateParent === parent;
+  const [open, setOpen] = useState(false);
+  const [items, setItems] = useState<SideExchange[]>([]);
+  const [snapshot, setSnapshot] = useState<SideHistory["snapshot"]>(null);
+  const [draft, setDraft] = useState("");
+  const [busy, setBusy] = useState(false);
+  const [loading, setLoading] = useState(false);
+  const [nextCursor, setNextCursor] = useState(0);
+  const [error, setError] = useState("");
+  const epoch = useRef(0);
+  const [streamEpoch, setStreamEpoch] = useState(0);
+  const cursor = useRef(0);
+  const submitting = useRef(false);
+  const retry = useRef<{ question: string; id: string } | null>(null);
+  const running = current ? items.find((item) => item.status === "running") : undefined;
+  const runningID = running?.id;
+
+  const load = useCallback(
+    async (before = 0) => {
+      if (!parent) return;
+      const version = epoch.current;
+      try {
+        const data = await sideAPI.history(parent, before);
+        if (version !== epoch.current) return;
+        setItems((old) => merge(old, data.items));
+        setSnapshot(data.snapshot);
+        setError("");
+        if (before || !cursor.current) {
+          cursor.current = data.next_cursor;
+          setNextCursor(data.next_cursor);
+        }
+      } catch (err) {
+        if (version === epoch.current) setError((err as Error).message);
+      }
+    },
+    [parent],
+  );
+
+  useEffect(() => {
+    epoch.current++;
+    setStateParent(parent);
+    setItems([]);
+    setSnapshot(null);
+    setNextCursor(0);
+    setDraft("");
+    setError("");
+    setBusy(false);
+    submitting.current = false;
+    retry.current = null;
+    cursor.current = 0;
+    if (!parent) {
+      setOpen(false);
+      setLoading(false);
+      return;
+    }
+    const version = epoch.current;
+    setLoading(true);
+    void sideAPI
+      .history(parent)
+      .then((data) => {
+        if (version !== epoch.current) return;
+        setItems((old) => merge(old, data.items));
+        setSnapshot(data.snapshot);
+        setNextCursor(data.next_cursor);
+        cursor.current = data.next_cursor;
+      })
+      .catch((err: Error) => {
+        if (version === epoch.current) setError(err.message);
+      })
+      .finally(() => {
+        if (version === epoch.current) setLoading(false);
+      });
+    return () => {
+      epoch.current++;
+    };
+  }, [parent]);
+
+  useEffect(() => {
+    if (!open || !parent) return;
+    void load();
+    const timer = setInterval(() => void load(), 2000);
+    return () => clearInterval(timer);
+  }, [open, parent, load]);
+
+  // biome-ignore lint/correctness/useExhaustiveDependencies: Reconnect after a clear attempt invalidates older callbacks.
+  useEffect(() => {
+    if (!runningID) return;
+    const version = epoch.current;
+    const stream = new EventSource(sseUrl(`/api/side-questions/${runningID}/events`));
+    stream.addEventListener("snapshot", (event) => {
+      if (version !== epoch.current) return;
+      try {
+        const item = JSON.parse((event as MessageEvent).data) as SideExchange;
+        if (item.id !== runningID) return;
+        setItems((old) => merge(old, [item]));
+        if (item.status !== "running") stream.close();
+      } catch {
+        setError("旁路数据解析失败，请重新打开面板");
+      }
+    });
+    stream.addEventListener("cleared", () => {
+      stream.close();
+      if (version === epoch.current) setItems([]);
+    });
+    return () => stream.close();
+  }, [runningID, streamEpoch]);
+
+  const ask = async (input: string) => {
+    const question = input.trim();
+    if (!parent || !question || submitting.current || running) return;
+    const version = epoch.current;
+    submitting.current = true;
+    setBusy(true);
+    setDraft(question);
+    setOpen(true);
+    if (retry.current?.question !== question) retry.current = { question, id: crypto.randomUUID() };
+    try {
+      const item = await sideAPI.ask(parent, question, retry.current.id);
+      if (version !== epoch.current) return;
+      setItems((old) => merge(old, [item]));
+      setDraft("");
+      setError("");
+      retry.current = null;
+      void load();
+    } catch (err) {
+      if (version === epoch.current) {
+        setError((err as Error).message);
+        toast.error((err as Error).message);
+      }
+    } finally {
+      if (version === epoch.current) {
+        submitting.current = false;
+        setBusy(false);
+      }
+    }
+  };
+
+  const handleCommand = (text: string, clear: () => void) => {
+    if (!parent || !isBtwCommand(text)) return false;
+    const question = text.trim().slice(4).trim();
+    setOpen(true);
+    clear();
+    if (question) {
+      setDraft(question);
+      void ask(question);
+    }
+    return true;
+  };
+
+  const clear = async () => {
+    if (!parent || submitting.current) return;
+    submitting.current = true;
+    setBusy(true);
+    const version = ++epoch.current;
+    try {
+      await sideAPI.clear(parent);
+      if (version !== epoch.current) return;
+      setItems([]);
+      setNextCursor(0);
+      cursor.current = 0;
+      setError("");
+      retry.current = null;
+    } catch (err) {
+      if (version === epoch.current) toast.error((err as Error).message);
+    } finally {
+      if (version === epoch.current) {
+        submitting.current = false;
+        setBusy(false);
+        setStreamEpoch((value) => value + 1);
+        void load();
+      }
+    }
+  };
+
+  const stop = async () => {
+    if (running) {
+      try {
+        await sideAPI.cancel(running.id);
+      } catch (err) {
+        toast.error((err as Error).message);
+      }
+    }
+  };
+  return {
+    open,
+    setOpen,
+    items: current ? items : [],
+    snapshot: current ? snapshot : null,
+    draft: current ? draft : "",
+    setDraft,
+    busy: current && busy,
+    loading: !current || loading,
+    error: current ? error : "",
+    running,
+    nextCursor: current ? nextCursor : 0,
+    load,
+    ask,
+    handleCommand,
+    clear,
+    stop,
+    enabled: !!parent,
+  };
+}
+
+export type SideQuestions = ReturnType<typeof useSideQuestions>;

web/src/lib/api.ts

@@ -91,7 +91,7 @@ function getToken(): string | null {
   return localStorage.getItem("artex_token");
 }
 
-async function http<T>(path: string, init?: RequestInit): Promise<T> {
+export async function http<T>(path: string, init?: RequestInit): Promise<T> {
   if (MOCK) return mockHandle<T>(init?.method ?? "GET", path, init?.body ?? null);
   const token = getToken();
   const r = await fetch(`/api${path}`, {

web/src/lib/side-questions.ts

@@ -0,0 +1,43 @@
+import { http } from "@/lib/api";
+
+export interface SideModel {
+  model: string;
+  name: string;
+  format: string;
+  profile_id: number;
+}
+export interface SideExchange {
+  id: string;
+  ordinal: number;
+  client_request_id: string;
+  question: string;
+  answer: string;
+  status: "running" | "completed" | "failed" | "cancelled" | "interrupted";
+  error?: string;
+  model: SideModel;
+  snapshot_at: string;
+  created_at: string;
+  sequence: number;
+}
+export interface SideHistory {
+  items: SideExchange[];
+  current: SideExchange | null;
+  next_cursor: number;
+  snapshot: { captured_at: string; model: SideModel; available: boolean; reason: string } | null;
+}
+
+async function request<T>(path: string, method = "GET", body?: unknown): Promise<T> {
+  return http<T>(path.replace(/^\/api/, ""), { method, body: body === undefined ? undefined : JSON.stringify(body) });
+}
+
+export const sideAPI = {
+  history: (parent: string, before = 0) => request<SideHistory>(`${parent}/side-questions?before=${before}`),
+  ask: (parent: string, question: string, client_request_id: string) =>
+    request<SideExchange>(`${parent}/side-questions`, "POST", { question, client_request_id }),
+  clear: (parent: string) => request(`${parent}/side-questions`, "DELETE"),
+  cancel: (id: string) => request(`/api/side-questions/${id}/cancel`, "POST"),
+};
+
+export function isBtwCommand(text: string) {
+  return /^\/btw(?:\s|$)/.test(text.trim());
+}