feat(web): continue from a subagent's work in a new chat tab

apps/web/src/components/AgentDetailView.tsx

@@ -41,6 +41,7 @@ import {
   ListFilterIcon,
   MessageCircleIcon,
   MessageSquarePlusIcon,
+  MessageSquareShareIcon,
   SquareArrowOutUpRightIcon,
   RefreshCw,
   SearchIcon,
@@ -635,6 +636,7 @@ export function AgentDetailView(props: {
   initialToolCallId?: string | null;
   onBack: () => void;
   onOpenInTab?: (() => void) | undefined;
+  onContinueInChat?: (() => void) | undefined;
 }) {
   const { agent } = props;
   const { timestampFormat } = useClientSettings();
@@ -682,6 +684,23 @@ export function AgentDetailView(props: {
                 <TooltipPopup side="bottom">Open in new tab</TooltipPopup>
               </Tooltip>
             ) : null}
+            {props.onContinueInChat ? (
+              <Tooltip>
+                <TooltipTrigger
+                  render={
+                    <Button
+                      size="icon-micro"
+                      variant="ghost-muted"
+                      aria-label="Continue in chat"
+                      onClick={props.onContinueInChat}
+                    />
+                  }
+                >
+                  <MessageSquareShareIcon aria-hidden />
+                </TooltipTrigger>
+                <TooltipPopup side="bottom">Continue in chat</TooltipPopup>
+              </Tooltip>
+            ) : null}
           </div>
         </div>
         <p className="truncate px-1 font-mono text-2xs text-muted-foreground">

apps/web/src/components/AgentsPanel.tsx

@@ -13,7 +13,7 @@
  * - Hovering a row previews the agent (prompt, latest tool calls, usage);
  *   the preview stays open under the pointer, and clicking it or the row opens
  *   the agent's detail view. Right-click a row to open that agent in its own
- *   tab. Filters and sorts never move a row while it works
+ *   tab or continue from its work in a new chat tab. Filters and sorts never move a row while it works
  *   (see applyAgentPanelView).
  */
 import { useAtomValue } from "@effect/atom-react";
@@ -23,6 +23,7 @@ import {
   findPanelAgent,
   isAgentPanelViewFiltered,
   type SubagentToolLogEntry,
+  subagentContinuationContext,
   subagentResultChatContext,
 } from "@t3tools/client-runtime/state/agentPanelView";
 import type {
@@ -54,6 +55,7 @@ import { orchestrationEnvironment } from "~/state/orchestration";
 import { ScrollArea } from "~/components/ui/scroll-area";
 import { Button } from "~/components/ui/button";
 import { PreviewCard, PreviewCardPopup, PreviewCardTrigger } from "~/components/ui/preview-card";
+import { toastManager } from "~/components/ui/toast";
 import { Tooltip, TooltipPopup, TooltipTrigger } from "~/components/ui/tooltip";
 
 import { AgentUsageFooter, TOOL_KIND_ICONS, ToolLogList, UsageFooter } from "./AgentActivityParts";
@@ -245,29 +247,36 @@ function AgentPreviewContent(props: {
   );
 }
 
+type AgentRowMenuAction = "open-in-tab" | "continue-in-chat" | "attach-result";
+
 /** Right-click on a list row. The same actions as the detail view's icons. */
 async function showAgentRowMenu(
   actions: {
     readonly openInTab?: (() => void) | undefined;
+    readonly continueInChat?: (() => void) | undefined;
     readonly attachResult?: (() => void) | undefined;
   },
   position: { readonly x: number; readonly y: number },
 ): Promise<void> {
   const api = readLocalApi();
   if (!api) return;
-  const items: ContextMenuItem<"open-in-tab" | "attach-result">[] = [
+  const items: ContextMenuItem<AgentRowMenuAction>[] = [
     ...(actions.openInTab ? [{ id: "open-in-tab" as const, label: "Open in new tab" }] : []),
+    ...(actions.continueInChat
+      ? [{ id: "continue-in-chat" as const, label: "Continue in chat" }]
+      : []),
     ...(actions.attachResult
       ? [{ id: "attach-result" as const, label: "Attach result to chat" }]
       : []),
   ];
-  let action: "open-in-tab" | "attach-result" | null;
+  let action: AgentRowMenuAction | null;
   try {
     action = await api.contextMenu.show(items, position);
   } catch {
     return;
   }
   if (action === "open-in-tab") actions.openInTab?.();
+  if (action === "continue-in-chat") actions.continueInChat?.();
   if (action === "attach-result") actions.attachResult?.();
 }
 
@@ -286,12 +295,14 @@ function AgentRow(props: {
   timestampFormat: TimestampFormat;
   onOpen: OpenAgent;
   onOpenInTab?: ((agent: RuntimeSubagent) => void) | undefined;
+  onContinueInChat?: ((agent: RuntimeSubagent) => void) | undefined;
 }) {
-  const { agent, onOpen, onOpenInTab } = props;
+  const { agent, onOpen, onOpenInTab, onContinueInChat } = props;
   const toolLog = props.toolLogs.get(agent.id) ?? NO_TOOL_CALLS;
   const composerRef = useComposerHandleContext();
   const menuActions = {
     openInTab: onOpenInTab ? () => onOpenInTab(agent) : undefined,
+    continueInChat: onContinueInChat ? () => onContinueInChat(agent) : undefined,
     attachResult:
       subagentResultChatContext(agent) !== null
         ? () => attachAgentResultToChat(composerRef, agent)
@@ -318,7 +329,7 @@ function AgentRow(props: {
             type="button"
             onClick={() => onOpen(agent.id)}
             onContextMenu={
-              menuActions.openInTab || menuActions.attachResult
+              menuActions.openInTab || menuActions.continueInChat || menuActions.attachResult
                 ? (event) => {
                     event.preventDefault();
                     event.stopPropagation();
@@ -355,6 +366,7 @@ interface RowContext {
   readonly timestampFormat: TimestampFormat;
   readonly onOpenAgent: OpenAgent;
   readonly onOpenInTab?: ((agent: RuntimeSubagent) => void) | undefined;
+  readonly onContinueInChat?: ((agent: RuntimeSubagent) => void) | undefined;
 }
 
 function Rows(props: { agents: ReadonlyArray<RuntimeSubagent>; ctx: RowContext }) {
@@ -366,6 +378,7 @@ function Rows(props: { agents: ReadonlyArray<RuntimeSubagent>; ctx: RowContext }
       timestampFormat={props.ctx.timestampFormat}
       onOpen={props.ctx.onOpenAgent}
       onOpenInTab={props.ctx.onOpenInTab}
+      onContinueInChat={props.ctx.onContinueInChat}
     />
   ));
 }
@@ -708,10 +721,13 @@ export function AgentsPanel({
   workspaceRoot,
   dedicatedAgentId,
   onOpenAgentTab,
+  onContinueInChat,
   onViewAgents,
 }: {
   dedicatedAgentId?: string | undefined;
   onOpenAgentTab?: ((agent: RuntimeSubagent) => void) | undefined;
+  /** Opens a chat tab seeded with the agent's work, as captured by `subagentContinuationContext`. */
+  onContinueInChat?: ((agent: RuntimeSubagent, context: string) => void) | undefined;
   onViewAgents?: (() => void) | undefined;
   model: AgentPanelModel;
   activities: ReadonlyArray<OrchestrationThreadActivity>;
@@ -737,13 +753,28 @@ export function AgentsPanel({
   );
   const detailAgentId = dedicatedAgentId ?? focusedAgentId;
   const focusedAgent = detailAgentId ? findPanelAgent(model, detailAgentId) : null;
+  const continueInChat = onContinueInChat
+    ? (agent: RuntimeSubagent) => {
+        const context = subagentContinuationContext(agent, toolLogs.get(agent.id) ?? NO_TOOL_CALLS);
+        if (context !== null) {
+          onContinueInChat(agent, context);
+          return;
+        }
+        toastManager.add({
+          type: "info",
+          title: "Nothing to continue from yet",
+          description: "This agent has no task, result, or tool calls to carry over.",
+        });
+      }
+    : undefined;
   const ctx: RowContext = {
     toolLogs,
     timestampFormat,
     onOpenAgent: (agentId, toolCallId) => {
       if (threadKey) focusAgent(threadKey, agentId, toolCallId ?? null);
     },
     onOpenInTab: onOpenAgentTab,
+    onContinueInChat: continueInChat,
   };
 
   if (dedicatedAgentId && !focusedAgent) {
@@ -786,6 +817,7 @@ export function AgentsPanel({
         onOpenInTab={
           !dedicatedAgentId && onOpenAgentTab ? () => onOpenAgentTab(focusedAgent) : undefined
         }
+        onContinueInChat={continueInChat ? () => continueInChat(focusedAgent) : undefined}
         onBack={() => {
           if (dedicatedAgentId) onViewAgents?.();
           else if (threadKey) focusAgent(threadKey, null);

apps/web/src/components/ChatView.tsx

@@ -239,6 +239,7 @@ import { WizardPopup } from "./ui/wizard";
 import {
   deriveAgentPanelModel,
   foldSubagentActivities,
+  type RuntimeSubagent,
 } from "@t3tools/client-runtime/state/subagentRuntime";
 import { BranchToolbar, type BranchToolbarHandle } from "./BranchToolbar";
 import { resolveShortcutCommand, shortcutLabelForCommand } from "../keybindings";
@@ -7509,6 +7510,26 @@ export default function ChatView(props: ChatViewProps) {
       await openForkedTab(tabRef);
     });
 
+  // From the Agents panel: a new tab of this thread whose draft carries the agent's work.
+  const onContinueAgentInChat = (agent: RuntimeSubagent, context: string) =>
+    runFork(async (connection) => {
+      if (!activeThread) return;
+      const tabRef = await forkThreadTab(connection, {
+        environmentId,
+        sourceThreadId: activeThread.id,
+        sourceTitle: activeThread.title,
+        modelSelection: activeThread.modelSelection,
+        prompt: "",
+        hasHistory: false,
+        context: {
+          producerId: `${activeThread.id}-agent-${agent.id}`,
+          title: agent.title,
+          summary: context,
+        },
+      });
+      await openForkedTab(tabRef);
+    });
+
   // From the model picker: the whole tab is summarized, the new tab runs the picked model, and
   // this tab's draft is copied after the summary. The draft here is left as it was.
   // `emptyDraftPrompt` stands in for the draft when there is none.
@@ -10217,6 +10238,7 @@ export default function ChatView(props: ChatViewProps) {
               }
             : undefined
         }
+        onContinueInChat={isServerThread ? onContinueAgentInChat : undefined}
         onViewAgents={() => {
           if (!activeThreadRef) return;
           useAgentsPanelStore.getState().focusAgent(scopedThreadKey(activeThreadRef), null);

apps/web/src/components/chat/ThreadTabs.tsx

@@ -489,18 +489,30 @@ async function captureThreadTabContext(
     summary?: string;
   },
 ): Promise<ComposerContextReference> {
-  const { threadId, sourceThreadId, title } = input;
   const summary = input.summary ?? (await fetchThreadTabSummary(connection, input));
-  const contextId = toKindScopedComposerContextId("thread-tab", sourceThreadId);
-  const label = sanitizeComposerContextLabel(title, "thread-tab");
+  return storeThreadTabContext(input.threadId, {
+    producerId: input.sourceThreadId,
+    sourceThreadId: input.sourceThreadId,
+    title: input.title,
+    summary,
+  });
+}
+
+/** Holds `summary` behind a chat-summary chip in the draft of `threadId`. */
+function storeThreadTabContext(
+  threadId: ThreadId,
+  input: { producerId: string; sourceThreadId: ThreadId; title: string; summary: string },
+): ComposerContextReference {
+  const contextId = toKindScopedComposerContextId("thread-tab", input.producerId);
+  const label = sanitizeComposerContextLabel(input.title, "thread-tab");
   useThreadTabContextStore.getState().upsert(threadId, {
     version: 1,
     kind: "thread-tab",
     contextId,
     label,
-    threadId: sourceThreadId,
-    title: title.slice(0, 2_048),
-    summary,
+    threadId: input.sourceThreadId,
+    title: input.title.slice(0, 2_048),
+    summary: input.summary.slice(0, COMPOSER_CONTEXT_THREAD_TAB_SUMMARY_MAX_CHARS),
   });
   return { kind: "thread-tab", contextId, label } satisfies ComposerContextReference;
 }
@@ -546,6 +558,11 @@ export async function forkThreadTab(
     prompt: string;
     /** False when forking from the chat's first message, which leaves nothing to summarize. */
     hasHistory: boolean;
+    /**
+     * Context captured by the caller, such as a subagent's work, attached in place of the source
+     * chat's summary. `producerId` keeps its chip distinct from the chat's own.
+     */
+    context?: { producerId: string; title: string; summary: string };
   },
 ): Promise<ScopedThreadRef> {
   const threadId = newThreadId();
@@ -557,15 +574,17 @@ export async function forkThreadTab(
   );
   const threadRef = scopeThreadRef(input.environmentId, threadId);
   carryRightPanelVisibility(scopeThreadRef(input.environmentId, input.sourceThreadId), threadRef);
-  const reference = input.hasHistory
-    ? await captureThreadTabContext(connection, {
-        threadId,
-        sourceThreadId: input.sourceThreadId,
-        title: input.sourceTitle,
-        ...(input.beforeMessageId ? { beforeMessageId: input.beforeMessageId } : {}),
-        ...(input.afterMessageId ? { afterMessageId: input.afterMessageId } : {}),
-      })
-    : null;
+  const reference = input.context
+    ? storeThreadTabContext(threadId, { ...input.context, sourceThreadId: input.sourceThreadId })
+    : input.hasHistory
+      ? await captureThreadTabContext(connection, {
+          threadId,
+          sourceThreadId: input.sourceThreadId,
+          title: input.sourceTitle,
+          ...(input.beforeMessageId ? { beforeMessageId: input.beforeMessageId } : {}),
+          ...(input.afterMessageId ? { afterMessageId: input.afterMessageId } : {}),
+        })
+      : null;
   useComposerDraftStore
     .getState()
     .setPrompt(

docs/fork-differences.md

@@ -147,6 +147,10 @@ Upstream's panel is a fixed list with one summary line per agent. To feed it:
   serves it with `retainedAt` once the provider can no longer answer.
 - **Attach result to chat** (detail view and list right-click) pastes the agent's task and
   result into the composer; `subagentResultChatContext` builds the text.
+- **Continue in chat** (detail view and list right-click) opens a new chat tab of the thread whose
+  draft carries the agent's task, result or error, and latest tool calls as a chat-summary chip;
+  `subagentContinuationContext` builds the text. It starts a fresh conversation rather than
+  resuming the agent's provider session.
 
 Code: `apps/web/src/components/AgentsPanel.tsx`, `AgentDetailView.tsx`,
 `apps/web/src/rightPanelStore.ts`, `packages/client-runtime/src/state/agentPanelView.ts`,

docs/user/thread-sidebar.md

@@ -280,6 +280,12 @@ chat** next to its result, or right-click the agent in the list. T3 Code adds
 the agent's task and result to the composer; a long result becomes a pasted
 attachment.
 
+To pick up an agent's line of work in its own conversation, choose **Continue
+in chat** in the agent's detail view, or right-click the agent in the list. A
+new chat tab opens with the agent's task, result, and tool calls attached, so
+you can ask follow-up questions or push the investigation further. The new
+chat starts fresh with that context; it does not resume the agent itself.
+
 | Provider    | Tool calls | Prompt                | Transcript |
 | ----------- | ---------- | --------------------- | ---------- |
 | Claude      | Yes        | Yes                   | Yes        |