feat(webui): add lightweight session messaging via mentions

2026-08-19 01:15:56 +08:00
parent 2bdb11eeba
commit 0e184965e8
76 changed files with 8297 additions and 658 deletions
@@ -50,6 +50,7 @@ import {
 } from "@/components/ui/tooltip";
 import { MAX_WORKBENCH_PANES } from "@/components/workbench/workbench-model";
 import { SIDEBAR_SELECTION_ITEM_CLASS } from "@/components/SidebarSelectionHighlight";
+import { SessionHandleHighlight, sessionHandleColor } from "@/components/CliAppMentionText";
 import { deriveTitle, relativeTime, visibleSessionPreview } from "@/lib/format";
 import {
  COLLAPSED_CHATS_VISIBLE_COUNT,
@@ -103,8 +104,10 @@ function SidebarItemTooltip({

 function SidebarSelectionTrack({
  active,
+  handle,
 }: {
  active: boolean;
+  handle: ChatSummary["handle"];
 }) {
  return (
    <span
@@ -112,14 +115,31 @@ function SidebarSelectionTrack({
      data-active={active ? "true" : "false"}
      aria-hidden
      className={cn(
-        "pointer-events-none absolute inset-x-0 bottom-0 h-0.5 origin-left rounded-full bg-current",
+        "pointer-events-none absolute inset-x-0 bottom-0 h-0.5 origin-left rounded-full",
        "transition-transform duration-200 ease-out motion-reduce:transition-none",
        active ? "scale-x-100" : "scale-x-0",
      )}
+      style={{
+        backgroundColor: handle ? sessionHandleColor(handle.color_slot) : "currentColor",
+      }}
    />
  );
 }

+function SidebarSessionHandle({ handle }: { handle: ChatSummary["handle"] }) {
+  if (!handle) return null;
+  return (
+    <span
+      data-sidebar-handle-handle
+      className="flex max-w-20 shrink-0 items-center overflow-hidden whitespace-nowrap text-[11px] font-medium leading-5"
+    >
+      <SessionHandleHighlight handle={handle}>
+        @{handle.name}
+      </SessionHandleHighlight>
+    </span>
+  );
+}
+
 function readCollapsedPaneGroups(): Set<string> {
  try {
    const value = JSON.parse(window.localStorage.getItem(
@@ -160,6 +180,7 @@ export interface SidebarPaneGroup {
    key: string;
    chatId: string;
    title: string;
+    handle?: ChatSummary["handle"];
  }>;
 }

@@ -965,27 +986,29 @@ export const ChatList = memo(function ChatList({
                                  partial={tabPartiallySelected}
                                />
                              ) : null}
-                              <span className="min-w-0 flex-1 overflow-hidden">
-                                {projectMode ? (
-                                  <span className="relative flex w-full min-w-0 items-baseline gap-2">
-                                    <span className="min-w-0 flex-1 truncate font-medium leading-5">
-                                      {title}
-                                    </span>
-                                    {isPinned ? <PinnedChatIndicator /> : null}
+                                <span className="min-w-0 flex-1 overflow-hidden">
+                                  {projectMode ? (
+                                    <span className="relative flex w-full min-w-0 items-baseline gap-2">
+                                      <SidebarSessionHandle handle={s.handle} />
+                                      <span className="min-w-0 flex-1 truncate font-medium leading-5">
+                                        {title}
+                                      </span>
+                                      {isPinned ? <PinnedChatIndicator /> : null}
                                    {timestamp ? (
                                      <span className="shrink-0 text-[11.5px] font-medium text-muted-foreground/58">
                                        {timestamp}
                                      </span>
                                    ) : null}
-                                    <SidebarSelectionTrack active={topicActive} />
+                                    <SidebarSelectionTrack active={topicActive} handle={s.handle} />
                                  </span>
                                ) : (
                                  <span className="relative flex w-full min-w-0 items-center gap-1.5">
+                                    <SidebarSessionHandle handle={s.handle} />
                                    <span className="min-w-0 flex-1 truncate font-medium leading-5">
                                      {title}
                                    </span>
                                    {isPinned ? <PinnedChatIndicator /> : null}
-                                    <SidebarSelectionTrack active={topicActive} />
+                                    <SidebarSelectionTrack active={topicActive} handle={s.handle} />
                                  </span>
                                )}
                                {showPreview ? (
@@ -1405,7 +1428,9 @@ function ActivePaneRows({
                  && "bg-sidebar-accent/55 text-sidebar-accent-foreground",
              )}
            >
-              <SidebarItemTooltip label={pane.title}>
+              <SidebarItemTooltip
+                label={pane.handle ? `@${pane.handle.name} · ${pane.title}` : pane.title}
+              >
                <button
                  type="button"
                  onClick={(event) => {
@@ -1437,9 +1462,10 @@ function ActivePaneRows({
                    <SelectionIndicator checked={selected} partial={false} />
                  ) : null}
                  <span className="relative flex min-w-0 flex-1 items-center gap-2 overflow-hidden">
+                    <SidebarSessionHandle handle={pane.handle} />
                    <span className="min-w-0 flex-1 truncate">{pane.title}</span>
                    {isPinned ? <PinnedChatIndicator /> : null}
-                    <SidebarSelectionTrack active={active} />
+                    <SidebarSelectionTrack active={active} handle={pane.handle} />
                  </span>
                </button>
              </SidebarItemTooltip>
@@ -1,4 +1,4 @@
-import { useMemo } from "react";
+import { useMemo, type ReactNode } from "react";
 import { useTranslation } from "react-i18next";

 import {
@@ -7,7 +7,12 @@ import {
 } from "@/components/InlineTokenHighlight";
 import { useLogoFallback } from "@/hooks/useLogoFallback";
 import { logoFallbackUrls } from "@/lib/provider-brand";
-import type { CliAppInfo, McpPresetInfo, SessionMention } from "@/lib/types";
+import type {
+  CliAppInfo,
+  McpPresetInfo,
+  SessionHandle,
+  SessionMention,
+} from "@/lib/types";
 import { cn } from "@/lib/utils";

 type CliAppMentionSegment =
@@ -17,8 +22,56 @@ type CliAppMentionSegment =
 export type CapabilityMentionSegment =
  | CliAppMentionSegment
  | { kind: "mcp"; text: string; preset: McpPresetInfo }
+  | { kind: "handle"; text: string; handle: SessionHandle };
+
+export type SessionReferenceSegment =
+  | { kind: "text"; text: string }
  | { kind: "session"; text: string; mention: SessionMention };

+export interface TokenSelection<T> {
+  mention: T;
+  start: number;
+  end: number;
+}
+
+export type SessionHandleSelection = TokenSelection<SessionHandle>;
+export type SessionMentionSelection = TokenSelection<SessionMention>;
+
+const SESSION_HANDLE_COLOR_COUNT = 8;
+
+export function sessionHandleColor(colorSlot: number): string {
+  const slot = Number.isFinite(colorSlot)
+    ? Math.abs(Math.trunc(colorSlot)) % SESSION_HANDLE_COLOR_COUNT
+    : 0;
+  return `var(--session-handle-${slot})`;
+}
+
+export function SessionHandleHighlight({
+  handle,
+  children,
+  className,
+  testId,
+}: {
+  handle: Pick<SessionHandle, "color_slot" | "name">;
+  children: ReactNode;
+  className?: string;
+  testId?: string;
+}) {
+  return (
+    <span
+      className="inline border-b-2"
+      style={{ borderBottomColor: sessionHandleColor(handle.color_slot) }}
+    >
+      <InlineTokenHighlight
+        testId={testId}
+        className={cn("text-foreground", className)}
+      >
+        {children}
+      </InlineTokenHighlight>
+    </span>
+  );
+}
+
 export function cliAppInitials(app: CliAppInfo): string {
  const value = app.display_name || app.name;
  return (
@@ -30,6 +83,7 @@ export function cliAppInitials(app: CliAppInfo): string {
      .join("") || app.name.slice(0, 2).toUpperCase()
  );
 }
+
 export function mcpPresetInitials(preset: Pick<McpPresetInfo, "name" | "display_name">): string {
  const value = preset.display_name || preset.name;
  return (
@@ -41,13 +95,15 @@ export function mcpPresetInitials(preset: Pick<McpPresetInfo, "name" | "display_
      .join("") || preset.name.slice(0, 2).toUpperCase()
  );
 }
+
 export function splitCapabilityMentionSegments(
  value: string,
  cliApps: CliAppInfo[],
  mcpPresets: McpPresetInfo[] = [],
-  sessionMentions: SessionMention[] = [],
+  sessionHandles: SessionHandle[] = [],
+  handleSelections?: SessionHandleSelection[],
 ): CapabilityMentionSegment[] {
-  if (!value || (cliApps.length === 0 && mcpPresets.length === 0 && sessionMentions.length === 0)) {
+  if (!value || (cliApps.length === 0 && mcpPresets.length === 0 && sessionHandles.length === 0)) {
    return value ? [{ kind: "text", text: value }] : [];
  }
  const cliAppsByName = new Map(
@@ -60,10 +116,13 @@ export function splitCapabilityMentionSegments(
      .filter((preset) => preset.installed && preset.configured)
      .map((preset) => [preset.name.toLowerCase(), preset]),
  );
-  const sessionsByName = new Map(
-    sessionMentions.map((mention) => [mention.name.toLowerCase(), mention]),
+  const handlesByName = new Map(
+    sessionHandles.map((handle) => [handle.name.toLowerCase(), handle]),
  );
-  if (cliAppsByName.size === 0 && mcpPresetsByName.size === 0 && sessionsByName.size === 0) {
+  const selectedSessionNames = new Set(
+    (handleSelections ?? []).map((selection) => selection.mention.name.toLowerCase()),
+  );
+  if (cliAppsByName.size === 0 && mcpPresetsByName.size === 0 && handlesByName.size === 0) {
    return [{ kind: "text", text: value }];
  }

@@ -75,13 +134,15 @@ export function splitCapabilityMentionSegments(
    const prefix = match[1] ?? "";
    const name = match[2] ?? "";
    const key = name.toLowerCase();
-    const app = cliAppsByName.get(key);
-    const preset = app ? null : mcpPresetsByName.get(key);
-    const session = app || preset ? null : sessionsByName.get(key);
-    if (!app && !preset && !session) continue;
-
    const mentionStart = match.index + prefix.length;
    const mentionEnd = mentionStart + name.length + 1;
+    const handle = handleSelections
+      ? selectedSessionNames.has(key) ? handlesByName.get(key) : undefined
+      : handlesByName.get(key);
+    const app = handle ? null : cliAppsByName.get(key);
+    const preset = handle || app ? null : mcpPresetsByName.get(key);
+    if (!app && !preset && !handle) continue;
+
    if (mentionStart > cursor) {
      segments.push({ kind: "text", text: value.slice(cursor, mentionStart) });
    }
@@ -89,18 +150,51 @@ export function splitCapabilityMentionSegments(
      segments.push({ kind: "cli", text: value.slice(mentionStart, mentionEnd), app });
    } else if (preset) {
      segments.push({ kind: "mcp", text: value.slice(mentionStart, mentionEnd), preset });
-    } else if (session) {
-      segments.push({
-        kind: "session",
-        text: value.slice(mentionStart, mentionEnd),
-        mention: session,
-      });
+    } else if (handle) {
+      segments.push({ kind: "handle", text: value.slice(mentionStart, mentionEnd), handle });
    }
    cursor = mentionEnd;
  }
-  if (cursor < value.length) {
-    segments.push({ kind: "text", text: value.slice(cursor) });
+  if (cursor < value.length) segments.push({ kind: "text", text: value.slice(cursor) });
+  return segments.length ? segments : [{ kind: "text", text: value }];
+}
+
+export function splitSessionReferenceSegments(
+  value: string,
+  sessionMentions: SessionMention[] = [],
+  sessionSelections?: SessionMentionSelection[],
+  allowLegacyAt = false,
+): SessionReferenceSegment[] {
+  if (!value || sessionMentions.length === 0) return value ? [{ kind: "text", text: value }] : [];
+  const sessionsByName = new Map(
+    sessionMentions.map((mention) => [mention.name.toLowerCase(), mention]),
+  );
+  const selectedSessionByStart = new Map(
+    (sessionSelections ?? []).map((selection) => [selection.start, selection]),
+  );
+  const segments: SessionReferenceSegment[] = [];
+  const referenceRe = allowLegacyAt
+    ? /(^|[\s([{])([#@])([\p{L}\p{N}_-]+)(?=$|[^\p{L}\p{N}_-])/giu
+    : /(^|[\s([{])(#)([\p{L}\p{N}_-]+)(?=$|[^\p{L}\p{N}_-])/giu;
+  let cursor = 0;
+  let match: RegExpExecArray | null;
+  while ((match = referenceRe.exec(value)) !== null) {
+    const prefix = match[1] ?? "";
+    const name = match[3] ?? "";
+    const start = match.index + prefix.length;
+    const end = start + name.length + 1;
+    const selected = selectedSessionByStart.get(start);
+    const mention = sessionSelections
+      ? selected?.end === end && selected.mention.name.toLowerCase() === name.toLowerCase()
+        ? selected.mention
+        : undefined
+      : sessionsByName.get(name.toLowerCase());
+    if (!mention) continue;
+    if (start > cursor) segments.push({ kind: "text", text: value.slice(cursor, start) });
+    segments.push({ kind: "session", text: value.slice(start, end), mention });
+    cursor = end;
  }
+  if (cursor < value.length) segments.push({ kind: "text", text: value.slice(cursor) });
  return segments.length ? segments : [{ kind: "text", text: value }];
 }

@@ -133,10 +227,42 @@ export function CapabilityMentionToken({
      />
    );
  }
-  return <SessionMentionToken mention={segment.mention} label={segment.text} variant={variant} />;
+  return <SessionHandleToken handle={segment.handle} label={segment.text} variant={variant} />;
 }

-export function SessionMentionToken({
+export function SessionHandleToken({
+  handle,
+  label,
+  variant,
+}: {
+  handle: SessionHandle;
+  label: string;
+  variant: "composer" | "message";
+}) {
+  const testIdPrefix = variant === "composer" ? "composer" : "message";
+  const color = sessionHandleColor(handle.color_slot);
+  const token = (
+    <SessionHandleHighlight
+      handle={handle}
+      testId={`${testIdPrefix}-handle-mention-${handle.name}`}
+      className={variant === "composer" ? "font-normal" : undefined}
+    >
+      {label}
+    </SessionHandleHighlight>
+  );
+  if (variant === "composer" || !handle.session_key) return token;
+  return (
+    <a
+      href={`#/chat/${encodeURIComponent(handle.session_key)}`}
+      className="rounded-sm underline-offset-2 hover:underline focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/60"
+      style={{ textDecorationColor: color }}
+    >
+      {token}
+    </a>
+  );
+}
+
+export function SessionReferenceToken({
  mention,
  label,
  variant,
@@ -148,7 +274,7 @@ export function SessionMentionToken({
  const testIdPrefix = variant === "composer" ? "composer" : "message";
  const token = (
    <InlineTokenHighlight
-      testId={`${testIdPrefix}-session-mention-${mention.name}`}
+      testId={`${testIdPrefix}-session-reference-${mention.name}`}
      title={`Session: ${mention.title || mention.name}`}
      color={INLINE_TOKEN_HIGHLIGHT_COLOR}
      className={variant === "composer" ? "font-normal" : undefined}
@@ -13,7 +13,7 @@ export function InlineTokenHighlight({
 }: {
  children: ReactNode;
  className?: string;
-  color: string;
+  color?: string;
  testId?: string;
  title?: string;
 }) {
@@ -25,7 +25,7 @@ export function InlineTokenHighlight({
        "relative inline font-[550] transition-colors duration-150",
        className,
      )}
-      style={{ color }}
+      style={color ? { color } : undefined}
    >
      {children}
    </span>
@@ -8,6 +8,7 @@ import {
 } from "react";

 import { cn } from "@/lib/utils";
+import type { SessionHandle } from "@/lib/types";

 interface MarkdownTextProps {
  children: string;
@@ -15,6 +16,7 @@ interface MarkdownTextProps {
  streaming?: boolean;
  preserveStreamingLayout?: boolean;
  onOpenFilePreview?: (path: string) => void;
+  sessionHandles?: SessionHandle[];
 }

 const loadMarkdownRenderer = () => import("@/components/MarkdownTextRenderer");
@@ -26,12 +28,14 @@ const MemoizedMarkdownRenderer = memo(function MemoizedMarkdownRenderer({
  highlightCode,
  streaming,
  onOpenFilePreview,
+  sessionHandles,
 }: {
  source: string;
  className?: string;
  highlightCode: boolean;
  streaming: boolean;
  onOpenFilePreview?: (path: string) => void;
+  sessionHandles?: SessionHandle[];
 }) {
  return (
    <LazyMarkdownRenderer
@@ -39,6 +43,7 @@ const MemoizedMarkdownRenderer = memo(function MemoizedMarkdownRenderer({
      highlightCode={highlightCode}
      streaming={streaming}
      onOpenFilePreview={onOpenFilePreview}
+      sessionHandles={sessionHandles}
    >
      {source}
    </LazyMarkdownRenderer>
@@ -77,6 +82,7 @@ export function MarkdownText({
  streaming = false,
  preserveStreamingLayout = false,
  onOpenFilePreview,
+  sessionHandles,
 }: MarkdownTextProps) {
  const renderedSource = children;
  const renderPhase = streaming ? "streaming" : "complete";
@@ -108,6 +114,7 @@ export function MarkdownText({
          highlightCode={highlightCode}
          streaming={renderWithStreamingLayout}
          onOpenFilePreview={onOpenFilePreview}
+          sessionHandles={sessionHandles}
        />
      </Suspense>
    </MarkdownRendererBoundary>
@@ -16,6 +16,7 @@ import { Streamdown, type Components, type StreamdownProps } from "streamdown";

 import { AttachmentTile } from "@/components/AttachmentTile";
 import { CodeBlock } from "@/components/CodeBlock";
+import { SessionHandleHighlight, sessionHandleColor } from "@/components/CliAppMentionText";
 import {
  INLINE_TOKEN_HIGHLIGHT_COLOR,
  InlineTokenHighlight,
@@ -34,6 +35,7 @@ import { inferMediaKind } from "@/lib/media";
 import { browserSafeFaviconUrls } from "@/lib/provider-brand";
 import { remarkTexMath } from "@/lib/remark-tex-math";
 import { cn } from "@/lib/utils";
+import type { SessionHandle } from "@/lib/types";

 import "katex/dist/katex.min.css";
 import "streamdown/styles.css";
@@ -44,11 +46,13 @@ interface MarkdownTextRendererProps {
  highlightCode?: boolean;
  streaming?: boolean;
  onOpenFilePreview?: (path: string) => void;
+  sessionHandles?: SessionHandle[];
 }

 type MarkdownAstNode = {
  type: string;
  value?: string;
+  url?: string;
  children?: MarkdownAstNode[];
  data?: {
    hName?: string;
@@ -277,7 +281,108 @@ function remarkCjkStrongBoundaries() {
  };
 }

-const remarkPlugins: NonNullable<StreamdownProps["remarkPlugins"]> = [
+const SESSION_HANDLE_PATTERN = /@([\p{L}\p{N}_-]+)/gu;
+const SESSION_HANDLE_SKIP_NODES = new Set([
+  "code",
+  "html",
+  "inlineCode",
+  "inlineMath",
+  "link",
+  "linkReference",
+  "math",
+]);
+const VOID_HTML_TAGS = new Set([
+  "area",
+  "base",
+  "br",
+  "col",
+  "embed",
+  "hr",
+  "img",
+  "input",
+  "link",
+  "meta",
+  "param",
+  "source",
+  "track",
+  "wbr",
+]);
+const RAW_HTML_TAG_PATTERN = /<\s*(\/?)\s*([a-z][\w:-]*)(?:\s[^<>]*?)?(\/?)\s*>/giu;
+
+function normalizeSessionHandle(value: string): string {
+  return value.normalize("NFKC").toLocaleLowerCase();
+}
+
+function sessionHandleNodes(
+  value: string,
+  handlesByName: ReadonlyMap<string, SessionHandle>,
+): MarkdownAstNode[] | null {
+  const replacement: MarkdownAstNode[] = [];
+  let cursor = 0;
+  for (const match of value.matchAll(SESSION_HANDLE_PATTERN)) {
+    const start = match.index;
+    const previous = start > 0 ? value[start - 1] : "";
+    if (previous && /[\p{L}\p{N}_@-]/u.test(previous)) continue;
+    const handle = handlesByName.get(normalizeSessionHandle(match[1]));
+    if (!handle) continue;
+    if (start > cursor) replacement.push(safeText(value.slice(cursor, start)));
+    replacement.push({
+      type: "link",
+      url: `#session-handle/${encodeURIComponent(handle.session_key)}`,
+      children: [safeText(match[0])],
+    });
+    cursor = start + match[0].length;
+  }
+  if (cursor === 0) return null;
+  if (cursor < value.length) replacement.push(safeText(value.slice(cursor)));
+  return replacement;
+}
+
+function rawHtmlNestingDelta(value: string | undefined): number {
+  if (!value) return 0;
+  let delta = 0;
+  for (const match of value.matchAll(RAW_HTML_TAG_PATTERN)) {
+    const closing = match[1] === "/";
+    const tagName = match[2].toLowerCase();
+    const selfClosing = match[3] === "/" || VOID_HTML_TAGS.has(tagName);
+    if (closing) delta -= 1;
+    else if (!selfClosing) delta += 1;
+  }
+  return delta;
+}
+
+function transformKnownSessionHandles(
+  node: MarkdownAstNode,
+  handlesByName: ReadonlyMap<string, SessionHandle>,
+): void {
+  if (
+    !node.children
+    || SESSION_HANDLE_SKIP_NODES.has(node.type)
+    || node.type.startsWith("nanobotSafeHtml")
+  ) return;
+  let rawHtmlDepth = 0;
+  node.children = node.children.flatMap((child) => {
+    if (child.type === "html") {
+      rawHtmlDepth = Math.max(0, rawHtmlDepth + rawHtmlNestingDelta(child.value));
+      return [child];
+    }
+    if (rawHtmlDepth > 0) return [child];
+    if (child.type !== "text" || !child.value?.includes("@")) {
+      transformKnownSessionHandles(child, handlesByName);
+      return [child];
+    }
+    return sessionHandleNodes(child.value, handlesByName) ?? [child];
+  });
+}
+
+function remarkKnownSessionHandles({ handles }: { handles: SessionHandle[] }) {
+  const handlesByName = new Map(
+    handles.map((handle) => [normalizeSessionHandle(handle.name), handle]),
+  );
+  return (tree: MarkdownAstNode) => transformKnownSessionHandles(tree, handlesByName);
+}
+
+const baseRemarkPlugins: NonNullable<StreamdownProps["remarkPlugins"]> = [
  remarkBreaks,
  remarkGfm,
  [remarkMath, { singleDollarTextMath: false }],
@@ -517,8 +622,22 @@ export default function MarkdownTextRenderer({
  highlightCode = true,
  streaming = false,
  onOpenFilePreview,
+  sessionHandles = [],
 }: MarkdownTextRendererProps) {
  const { t } = useTranslation();
+  const handlesBySessionKey = useMemo(
+    () => new Map(sessionHandles.map((handle) => [handle.session_key, handle])),
+    [sessionHandles],
+  );
+  const remarkPlugins = useMemo(
+    () => sessionHandles.length > 0
+      ? [
+          ...baseRemarkPlugins,
+          [remarkKnownSessionHandles, { handles: sessionHandles }],
+        ] as NonNullable<StreamdownProps["remarkPlugins"]>
+      : baseRemarkPlugins,
+    [sessionHandles],
+  );
  const components = useMemo<Components>(
    () => ({
      code({ className: cls, children: kids, node: _node, ...props }) {
@@ -612,6 +731,30 @@ export default function MarkdownTextRenderer({
        if (href === "streamdown:incomplete-link") {
          return <>{markdownChildren}</>;
        }
+        if (href.startsWith("#session-handle/")) {
+          let handle: SessionHandle | undefined;
+          try {
+            handle = handlesBySessionKey.get(decodeURIComponent(href.slice("#session-handle/".length)));
+          } catch {
+            handle = undefined;
+          }
+          if (!handle) return <>{markdownChildren}</>;
+          const color = sessionHandleColor(handle.color_slot);
+          return (
+            <a
+              href={`#/chat/${encodeURIComponent(handle.session_key)}`}
+              className="rounded-sm no-underline focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/60"
+              style={{ textDecorationColor: color }}
+            >
+              <SessionHandleHighlight
+                handle={handle}
+                testId={`message-handle-mention-${handle.name}`}
+              >
+                {markdownChildren}
+              </SessionHandleHighlight>
+            </a>
+          );
+        }
        const sessionHref = sessionReferenceHref(href);
        if (sessionHref) {
          return (
@@ -790,7 +933,7 @@ export default function MarkdownTextRenderer({
        );
      },
    }),
-    [highlightCode, onOpenFilePreview, t],
+    [highlightCode, onOpenFilePreview, handlesBySessionKey, t],
  );

  return (
@@ -20,6 +20,7 @@ import {
 import { useTranslation } from "react-i18next";

 import { AttachmentTile } from "@/components/AttachmentTile";
+import { sessionHandleColor } from "@/components/CliAppMentionText";
 import { ImageLightbox } from "@/components/ImageLightbox";
 import { MarkdownText } from "@/components/MarkdownText";
 import { SlashCommandText } from "@/components/SlashCommandText";
@@ -48,6 +49,7 @@ import type {
  UIMessage,
  MessageDeliveryErrorKind,
  MessageDeliveryStatus,
+  SessionHandle,
 } from "@/lib/types";

 interface MessageBubbleProps {
@@ -61,6 +63,7 @@ interface MessageBubbleProps {
  cliApps?: CliAppInfo[];
  mcpPresets?: McpPresetInfo[];
  slashCommands?: SlashCommand[];
+  sessionDirectory?: SessionHandle[];
  onOpenFilePreview?: (path: string) => void;
  onForkFromHere?: () => void;
 }
@@ -259,6 +262,77 @@ function UserDeliveryStatus({
  );
 }

+function IncomingSessionMessage({
+  message,
+  showCopyAction,
+  sessionDirectory,
+  onOpenFilePreview,
+}: {
+  message: UIMessage;
+  showCopyAction: boolean;
+  sessionDirectory: SessionHandle[];
+  onOpenFilePreview?: (path: string) => void;
+}) {
+  const handle = message.sessionMessage!.session;
+  const activeSession = sessionDirectory.find((candidate) => candidate.id === handle.id);
+  const color = sessionHandleColor(handle.color_slot);
+  const createdAtLabel = formatMessageEndTime(message.createdAt);
+  const handleName = `@${handle.name}`;
+  const name = <span className="font-medium text-foreground">{handleName}</span>;
+
+  return (
+    <div
+      data-handle-message="incoming"
+      className="group w-full text-[15px]"
+      style={{ lineHeight: "var(--cjk-line-height)" }}
+    >
+      <div
+        data-handle-message-body
+        className="min-w-0 rounded-es-[16px] border-s-2 bg-background pb-1 ps-2.5"
+        style={{ borderInlineStartColor: color }}
+      >
+        <div className="mb-1.5 flex items-center text-[12px] text-muted-foreground">
+          {activeSession?.session_key ? (
+            <a
+              href={`#/chat/${encodeURIComponent(activeSession.session_key)}`}
+              className="rounded-sm underline-offset-2 hover:underline focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/60"
+            >
+              {name}
+            </a>
+          ) : name}
+        </div>
+        <div data-assistant-selectable="true" className="min-w-0">
+          <MarkdownText
+            preserveStreamingLayout
+            onOpenFilePreview={onOpenFilePreview}
+            sessionHandles={sessionDirectory}
+          >
+            {message.content}
+          </MarkdownText>
+        </div>
+      </div>
+      {createdAtLabel || showCopyAction ? (
+        <TooltipProvider delayDuration={220} skipDelayDuration={80}>
+          <div
+            data-handle-footer
+            className="mt-1 flex min-h-8 items-center gap-1.5 text-muted-foreground"
+          >
+            {showCopyAction ? <MessageCopyButton content={message.content} /> : null}
+            {createdAtLabel ? (
+              <MessageTimestamp
+                timestamp={message.createdAt}
+                tooltipLabel={fmtDateTime(message.createdAt)}
+              >
+                {createdAtLabel}
+              </MessageTimestamp>
+            ) : null}
+          </div>
+        </TooltipProvider>
+      ) : null}
+    </div>
+  );
+}
+
 /** Render user turns as compact bubbles and assistant turns as document-like prose. */
 export function MessageBubble({
  message,
@@ -268,6 +342,7 @@ export function MessageBubble({
  cliApps = [],
  mcpPresets = [],
  slashCommands = [],
+  sessionDirectory = [],
  onOpenFilePreview,
  onForkFromHere,
 }: MessageBubbleProps) {
@@ -285,6 +360,17 @@ export function MessageBubble({
    return <TraceGroup message={message} />;
  }

+  if (message.role === "user" && message.sessionMessage?.direction === "incoming") {
+    return (
+      <IncomingSessionMessage
+        message={message}
+        showCopyAction={showCopyAction}
+        sessionDirectory={sessionDirectory}
+        onOpenFilePreview={onOpenFilePreview}
+      />
+    );
+  }
+
  if (message.role === "user") {
    const images = message.images ?? [];
    const media = message.media ?? [];
@@ -308,6 +394,9 @@ export function MessageBubble({
          cliApps={mentionCliApps}
          mcpPresets={mentionMcpPresets}
          sessionMentions={message.sessionMentions}
+          sessionHandles={message.sessionHandles}
+          attachedCliApps={message.cliApps}
+          attachedMcpPresets={message.mcpPresets}
        />
      </>
    ) : (
@@ -316,6 +405,9 @@ export function MessageBubble({
        cliApps={mentionCliApps}
        mcpPresets={mentionMcpPresets}
        sessionMentions={message.sessionMentions}
+        sessionHandles={message.sessionHandles}
+        attachedCliApps={message.cliApps}
+        attachedMcpPresets={message.mcpPresets}
      />
    );
    return (
@@ -433,6 +525,7 @@ export function MessageBubble({
              streaming={!!message.isStreaming}
              preserveStreamingLayout
              onOpenFilePreview={onOpenFilePreview}
+              sessionHandles={sessionDirectory}
            >
              {message.content}
            </MarkdownText>
@@ -3,14 +3,24 @@ import { useTranslation } from "react-i18next";

 import {
  CapabilityMentionToken,
+  SessionReferenceToken,
  splitCapabilityMentionSegments,
+  splitSessionReferenceSegments,
  type CapabilityMentionSegment,
+  type SessionReferenceSegment,
 } from "@/components/CliAppMentionText";
 import {
  INLINE_TOKEN_HIGHLIGHT_COLOR,
  InlineTokenHighlight,
 } from "@/components/InlineTokenHighlight";
-import type { CliAppInfo, McpPresetInfo, SessionMention } from "@/lib/types";
+import type {
+  CliAppInfo,
+  McpPresetInfo,
+  SessionHandle,
+  SessionMention,
+  UICliAppAttachment,
+  UIMcpPresetAttachment,
+} from "@/lib/types";

 type SkillReferenceSegment =
  | { kind: "text"; text: string }
@@ -18,6 +28,7 @@ type SkillReferenceSegment =

 type UserMessageSegment =
  | CapabilityMentionSegment
+  | SessionReferenceSegment
  | { kind: "skill"; text: string; name: string };

 function splitSkillReferenceSegments(value: string): SkillReferenceSegment[] {
@@ -49,18 +60,75 @@ function splitUserMessageSegments(
  cliApps: CliAppInfo[],
  mcpPresets: McpPresetInfo[],
  sessionMentions: SessionMention[],
+  sessionHandles: SessionHandle[],
+  attachedCliApps: UICliAppAttachment[],
+  attachedMcpPresets: UIMcpPresetAttachment[],
 ): UserMessageSegment[] {
  const segments: UserMessageSegment[] = [];
-  for (const segment of splitCapabilityMentionSegments(
-    value,
-    cliApps,
-    mcpPresets,
-    sessionMentions,
-  )) {
-    if (segment.kind === "text") {
-      segments.push(...splitSkillReferenceSegments(segment.text));
-    } else {
-      segments.push(segment);
+  const structuredAtNamespaces = new Map<string, "handle" | "cli" | "mcp">();
+  sessionHandles.forEach((handle) => {
+    structuredAtNamespaces.set(handle.name.toLowerCase(), "handle");
+  });
+  attachedCliApps.forEach((app) => {
+    const name = app.name.toLowerCase();
+    if (!structuredAtNamespaces.has(name)) structuredAtNamespaces.set(name, "cli");
+  });
+  attachedMcpPresets.forEach((preset) => {
+    const name = preset.name.toLowerCase();
+    if (!structuredAtNamespaces.has(name)) structuredAtNamespaces.set(name, "mcp");
+  });
+  const structuredAtNames = new Set(structuredAtNamespaces.keys());
+  const replayCliApps = cliApps.filter((app) => {
+    const owner = structuredAtNamespaces.get(app.name.toLowerCase());
+    return owner === undefined || owner === "cli";
+  });
+  const replayMcpPresets = mcpPresets.filter((preset) => {
+    const owner = structuredAtNamespaces.get(preset.name.toLowerCase());
+    return owner === undefined || owner === "mcp";
+  });
+  const replaySessionHandles = sessionHandles.filter((handle) => (
+    structuredAtNamespaces.get(handle.name.toLowerCase()) === "handle"
+  ));
+  const hashSegments = splitSessionReferenceSegments(value, sessionMentions);
+  const hashSessionKeys = new Set(hashSegments.flatMap((segment) => (
+    segment.kind === "session" ? [segment.mention.session_key] : []
+  )));
+  const legacySessionMentions = sessionMentions.filter((mention) => (
+    !hashSessionKeys.has(mention.session_key)
+    && !structuredAtNames.has(mention.name.toLowerCase())
+  ));
+
+  const appendCapabilitiesAndSkills = (text: string) => {
+    for (const capability of splitCapabilityMentionSegments(
+      text,
+      replayCliApps,
+      replayMcpPresets,
+      replaySessionHandles,
+    )) {
+      if (capability.kind === "text") {
+        segments.push(...splitSkillReferenceSegments(capability.text));
+      } else {
+        segments.push(capability);
+      }
+    }
+  };
+
+  for (const hashSegment of hashSegments) {
+    if (hashSegment.kind === "session") {
+      segments.push(hashSegment);
+      continue;
+    }
+    for (const legacySegment of splitSessionReferenceSegments(
+      hashSegment.text,
+      legacySessionMentions,
+      undefined,
+      true,
+    )) {
+      if (legacySegment.kind === "session") {
+        segments.push(legacySegment);
+      } else {
+        appendCapabilitiesAndSkills(legacySegment.text);
+      }
    }
  }
  return segments;
@@ -71,14 +139,28 @@ export function UserMessageText({
  cliApps,
  mcpPresets,
  sessionMentions = [],
+  sessionHandles = [],
+  attachedCliApps = [],
+  attachedMcpPresets = [],
 }: {
  text: string;
  cliApps: CliAppInfo[];
  mcpPresets: McpPresetInfo[];
  sessionMentions?: SessionMention[];
+  sessionHandles?: SessionHandle[];
+  attachedCliApps?: UICliAppAttachment[];
+  attachedMcpPresets?: UIMcpPresetAttachment[];
 }) {
  const { t } = useTranslation();
-  const segments = splitUserMessageSegments(text, cliApps, mcpPresets, sessionMentions);
+  const segments = splitUserMessageSegments(
+    text,
+    cliApps,
+    mcpPresets,
+    sessionMentions,
+    sessionHandles,
+    attachedCliApps,
+    attachedMcpPresets,
+  );
  return (
    <>
      {segments.map((segment, index) => {
@@ -95,6 +177,14 @@ export function UserMessageText({
            {segment.name}
          </InlineTokenHighlight>
        );
+        if (segment.kind === "session") return (
+          <SessionReferenceToken
+            key={`session-${segment.mention.session_key}-${index}`}
+            mention={segment.mention}
+            label={segment.text}
+            variant="message"
+          />
+        );
        return (
          <CapabilityMentionToken
            key={`${segment.kind}-${index}`}
@@ -3,6 +3,7 @@ import { type ReactNode } from "react";
 import { useTranslation } from "react-i18next";

 import { Button } from "@/components/ui/button";
+import { SessionHandleHighlight } from "@/components/CliAppMentionText";
 import {
  Tooltip,
  TooltipContent,
@@ -10,9 +11,11 @@ import {
  TooltipTrigger,
 } from "@/components/ui/tooltip";
 import { cn } from "@/lib/utils";
+import type { SessionHandle } from "@/lib/types";

 interface ThreadHeaderProps {
  title: string;
+  handle?: SessionHandle | null;
  onToggleSidebar: () => void;
  theme: "light" | "dark";
  onToggleTheme: () => void;
@@ -32,6 +35,7 @@ interface ThreadHeaderProps {

 export function ThreadHeader({
  title,
+  handle = null,
  onToggleSidebar,
  theme,
  onToggleTheme,
@@ -79,6 +83,16 @@ export function ThreadHeader({
            <span className="max-w-[min(60vw,32rem)] truncate">{title}</span>
          </div>
        ) : null}
+        {handle ? (
+          <span
+            data-testid="thread-handle-handle"
+            className="flex shrink-0 items-center rounded-md px-1.5 py-1 text-[12px] font-medium"
+          >
+            <SessionHandleHighlight handle={handle}>
+              @{handle.name}
+            </SessionHandleHighlight>
+          </span>
+        ) : null}
      </div>

      <div className="ml-auto flex shrink-0 items-center gap-1">
@@ -4,7 +4,13 @@ import { MessageBubble } from "@/components/MessageBubble";
 import { AgentActivityCluster } from "@/components/thread/AgentActivityCluster";
 import { AssistantSelectionAction } from "@/components/thread/AssistantSelectionAction";
 import { normalizeActivityTimeline, type TurnUnit } from "@/lib/activity-timeline";
-import type { CliAppInfo, McpPresetInfo, SlashCommand, UIMessage } from "@/lib/types";
+import type {
+  CliAppInfo,
+  McpPresetInfo,
+  SessionHandle,
+  SlashCommand,
+  UIMessage,
+} from "@/lib/types";

 interface ThreadMessagesProps {
  messages: UIMessage[];
@@ -18,6 +24,7 @@ interface ThreadMessagesProps {
  cliApps?: CliAppInfo[];
  mcpPresets?: McpPresetInfo[];
  slashCommands?: SlashCommand[];
+  sessionDirectory?: SessionHandle[];
  forkBoundaryMessageCount?: number | null;
  onOpenFilePreview?: (path: string) => void;
  onForkFromMessage?: (beforeUserIndex: number) => void;
@@ -62,6 +69,7 @@ export function ThreadMessages({
  cliApps = [],
  mcpPresets = [],
  slashCommands = [],
+  sessionDirectory = [],
  forkBoundaryMessageCount = null,
  onOpenFilePreview,
  onForkFromMessage,
@@ -159,6 +167,7 @@ export function ThreadMessages({
            cliApps={cliApps}
            mcpPresets={mcpPresets}
            slashCommands={slashCommands}
+            sessionDirectory={sessionDirectory}
            onOpenFilePreview={onOpenFilePreview}
            onForkFromMessage={onForkFromMessage}
          />
@@ -240,6 +249,7 @@ interface ThreadDisplayUnitProps {
  cliApps: CliAppInfo[];
  mcpPresets: McpPresetInfo[];
  slashCommands: SlashCommand[];
+  sessionDirectory: SessionHandle[];
  onOpenFilePreview?: (path: string) => void;
  onForkFromMessage?: (beforeUserIndex: number) => void;
 }
@@ -258,6 +268,7 @@ const ThreadDisplayUnit = memo(function ThreadDisplayUnit({
  cliApps,
  mcpPresets,
  slashCommands,
+  sessionDirectory,
  onOpenFilePreview,
  onForkFromMessage,
 }: ThreadDisplayUnitProps) {
@@ -296,6 +307,7 @@ const ThreadDisplayUnit = memo(function ThreadDisplayUnit({
            cliApps={cliApps}
            mcpPresets={mcpPresets}
            slashCommands={slashCommands}
+            sessionDirectory={sessionDirectory}
            onOpenFilePreview={onOpenFilePreview}
            onForkFromHere={forkIndex !== undefined ? onForkFromHere : undefined}
          />
@@ -324,6 +336,7 @@ function threadDisplayUnitPropsEqual(
    && previous.cliApps === next.cliApps
    && previous.mcpPresets === next.mcpPresets
    && previous.slashCommands === next.slashCommands
+    && previous.sessionDirectory === next.sessionDirectory
    && previous.onOpenFilePreview === next.onOpenFilePreview
    && previous.onForkFromMessage === next.onForkFromMessage
  );
@@ -5,6 +5,7 @@ import { useTranslation } from "react-i18next";

 import { FilePreviewAvailabilityProvider } from "@/components/FilePreviewAvailabilityContext";
 import { FilePreviewPanel } from "@/components/FilePreviewPanel";
+import { SessionHandleHighlight } from "@/components/CliAppMentionText";
 import { PromptNavigator } from "@/components/thread/PromptNavigator";
 import { SessionInfoPopover } from "@/components/thread/SessionInfoPopover";
 import { ThreadComposer } from "@/components/thread/ThreadComposer";
@@ -36,6 +37,7 @@ import type { CanonicalRunSnapshot, StreamError } from "@/lib/nanobot-client";
 import { inferProviderFromModelName, providerDisplayLabel } from "@/lib/provider-brand";
 import type {
  ChatSummary,
+  SessionHandle,
  SettingsPayload,
  SlashCommand,
  SkillSummary,
@@ -637,7 +639,7 @@ export function ThreadShell({
  const { t } = useTranslation();
  const chatId = session?.chatId ?? null;
  const historyKey = temporary ? null : session?.key ?? null;
-  const mentionSessions = useMemo(
+  const referenceSessions = useMemo(
    () => sessions.filter((candidate) => (
      candidate.key !== historyKey
      && (
@@ -647,6 +649,18 @@ export function ThreadShell({
    )),
    [historyKey, sessions, workspaceScope],
  );
+  const handleSessions = useMemo(() => {
+    if (temporary) return [];
+    return sessions;
+  }, [sessions, temporary]);
+  const sessionDirectory = useMemo<SessionHandle[]>(() => {
+    const handles = new Map<string, SessionHandle>();
+    if (session?.handle) handles.set(session.handle.id, session.handle);
+    for (const candidate of handleSessions) {
+      if (candidate.handle) handles.set(candidate.handle.id, candidate.handle);
+    }
+    return [...handles.values()];
+  }, [handleSessions, session?.handle]);
  const {
    messages: historical,
    loading,
@@ -1316,7 +1330,14 @@ export function ThreadShell({
      setPendingFirstTargetChatId(newId);
      return true;
    },
-    [booting, client, localModelPreset, onCreateChat, withWorkspaceScope, workspaceScope],
+    [
+      booting,
+      client,
+      localModelPreset,
+      onCreateChat,
+      withWorkspaceScope,
+      workspaceScope,
+    ],
  );

  const handleThreadSend = useCallback(
@@ -1469,7 +1490,8 @@ export function ThreadShell({
          slashCommands={availableSlashCommands}
          cliApps={cliApps}
          mcpPresets={mcpPresets}
-          sessions={mentionSessions}
+          sessions={referenceSessions}
+          handleSessions={handleSessions}
          skills={skills}
          onStop={stop}
          onTranscribeAudio={transcribeAudio}
@@ -1516,7 +1538,8 @@ export function ThreadShell({
          slashCommands={availableSlashCommands}
          cliApps={cliApps}
          mcpPresets={mcpPresets}
-          sessions={mentionSessions}
+          sessions={referenceSessions}
+          handleSessions={handleSessions}
          skills={skills}
          surfaceRef={composerSurfaceRef}
          onTranscribeAudio={transcribeAudio}
@@ -1560,6 +1583,7 @@ export function ThreadShell({
  const threadHeader = !hideHeader ? (
    <ThreadHeader
      title={title}
+      handle={temporary || hideHeaderTitle ? null : session?.handle}
      onToggleSidebar={onToggleSidebar}
      theme={theme}
      onToggleTheme={onToggleTheme}
@@ -1583,6 +1607,23 @@ export function ThreadShell({
  return (
    <section ref={shellRef} className="relative flex min-h-0 flex-1 overflow-hidden">
      <div className="relative flex min-w-0 flex-1 flex-col overflow-hidden">
+        {hideHeaderTitle && !temporary && session?.handle ? (
+          <div
+            data-testid="pane-handle-identity"
+            data-active={headerActive ? "true" : "false"}
+            aria-label={`Session @${session.handle.name}`}
+            className="flex h-8 shrink-0 items-center px-3 text-[12px]"
+          >
+            <span
+              data-pane-handle-handle
+              className="shrink-0"
+            >
+              <SessionHandleHighlight handle={session.handle}>
+                @{session.handle.name}
+              </SessionHandleHighlight>
+            </span>
+          </div>
+        ) : null}
        {headerPortalTarget === undefined ? threadHeader : null}
        <FilePreviewAvailabilityProvider
          resolve={historyKey ? resolveFilePreviewAvailability : undefined}
@@ -1602,6 +1643,7 @@ export function ThreadShell({
            showScrollToBottomButton={!!session}
            cliApps={cliApps}
            mcpPresets={mcpPresets}
+            sessionDirectory={sessionDirectory}
            slashCommands={availableSlashCommands}
            forkBoundaryMessageCount={forkBoundaryMessageCount}
            hasMoreBefore={hasMoreBefore}
@@ -26,7 +26,13 @@ import {
  promptTop,
 } from "@/components/thread/promptNavigation";
 import { cn } from "@/lib/utils";
-import type { CliAppInfo, McpPresetInfo, SlashCommand, UIMessage } from "@/lib/types";
+import type {
+  CliAppInfo,
+  McpPresetInfo,
+  SessionHandle,
+  SlashCommand,
+  UIMessage,
+} from "@/lib/types";

 export interface ThreadViewportHandle {
  jumpToUserPrompt: (promptId: string) => void;
@@ -50,6 +56,7 @@ interface ThreadViewportProps {
  cliApps?: CliAppInfo[];
  mcpPresets?: McpPresetInfo[];
  slashCommands?: SlashCommand[];
+  sessionDirectory?: SessionHandle[];
  forkBoundaryMessageCount?: number | null;
  hasMoreBefore?: boolean;
  loadingOlder?: boolean;
@@ -69,6 +76,7 @@ const SOFT_KEYBOARD_MIN_INSET_PX = 80;
 const SESSION_HANDOFF_EXIT_DURATION_MS = 80;
 const SESSION_HANDOFF_ENTER_DURATION_MS = 140;
 const SESSION_HANDOFF_OPACITY = 0.82;
+const EMPTY_SESSION_DIRECTORY: SessionHandle[] = [];
 export const INITIAL_HISTORY_WINDOW = 160;
 export const HISTORY_WINDOW_INCREMENT = 120;

@@ -104,11 +112,6 @@ function isKeyboardEditableElement(element: Element | null): element is HTMLElem
  ].includes(element.type);
 }

-function isThreadDisclosureTarget(target: EventTarget | null): boolean {
-  return target instanceof Element
-    && target.closest("[data-thread-disclosure]") !== null;
-}
-
 function isKeyboardControl(element: Element | null): boolean {
  return element instanceof HTMLElement
    && element.closest(
@@ -116,6 +119,11 @@ function isKeyboardControl(element: Element | null): boolean {
    ) !== null;
 }

+function isThreadDisclosureTarget(target: EventTarget | null): boolean {
+  return target instanceof Element
+    && target.closest("[data-thread-disclosure]") !== null;
+}
+
 type ThreadScrollDirection = "backward" | "forward";

 const KEYBOARD_SCROLL_DIRECTIONS: Readonly<
@@ -185,6 +193,7 @@ export const ThreadViewport = forwardRef<ThreadViewportHandle, ThreadViewportPro
  cliApps = [],
  mcpPresets = [],
  slashCommands = [],
+  sessionDirectory = EMPTY_SESSION_DIRECTORY,
  forkBoundaryMessageCount = null,
  hasMoreBefore = false,
  loadingOlder = false,
@@ -762,6 +771,7 @@ export const ThreadViewport = forwardRef<ThreadViewportHandle, ThreadViewportPro
                  cliApps={cliApps}
                  mcpPresets={mcpPresets}
                  slashCommands={slashCommands}
+                  sessionDirectory={sessionDirectory}
                  forkBoundaryMessageCount={visibleForkBoundaryMessageCount}
                  onOpenFilePreview={onOpenFilePreview}
                  onForkFromMessage={onForkFromMessage}
@@ -15,6 +15,8 @@ export interface ToolField {
    | "key"
    | "label"
    | "name"
+    | "to"
+    | "expect_reply"
    | "channel"
    | "chat_id"
    | "session_id"
@@ -119,7 +121,7 @@ export function describeGenericToolRun(items: GenericToolRunItem[]): GenericTool
    status,
    label: activityLabel(family, status, collected, name, items),
    detail: activityDetail(items, family, name),
-    aside: activityAside(items, family),
+    aside: activityAside(items, family, name),
  };
 }

@@ -168,6 +170,7 @@ function safeFields(args: unknown): ToolField[] {
    "key",
    "label",
    "name",
+    "to",
    "channel",
    "chat_id",
    "session_id",
@@ -178,6 +181,17 @@ function safeFields(args: unknown): ToolField[] {
      fields.push({ key, value: value.trim() });
    }
  }
+  const expectReply = record.expect_reply;
+  if (typeof expectReply === "boolean") {
+    fields.push({ key: "expect_reply", value: String(expectReply) });
+  } else if (typeof expectReply === "string") {
+    const normalized = expectReply.toLowerCase();
+    if (["true", "1", "yes"].includes(normalized)) {
+      fields.push({ key: "expect_reply", value: "true" });
+    } else if (["false", "0", "no"].includes(normalized)) {
+      fields.push({ key: "expect_reply", value: "false" });
+    }
+  }
  return fields;
 }

@@ -226,6 +240,18 @@ function activityLabel(
      return statusCopy(status, "Generating image", "Generated image", "Could not generate image");
    case "spawn":
      return statusCopy(status, "Delegating task", "Delegated task", "Could not delegate task");
+    case "send_session_message":
+      if (items.length > 1) {
+        return statusCopy(
+          status,
+          "Sending messages",
+          "Sent messages",
+          "Could not send messages",
+        );
+      }
+      return fieldValue(items[0]?.trace, "expect_reply") === "true"
+        ? statusCopy(status, "Asking", "Asked", "Could not reach")
+        : statusCopy(status, "Sending to", "Sent to", "Could not reach");
    case "message":
      return statusCopy(status, "Sending message", "Sent message", "Could not send message");
    case "my":
@@ -281,6 +307,8 @@ function activityDetail(items: GenericToolRunItem[], family: ToolFamily, name: s
  switch (name) {
    case "spawn":
      return safeText(fieldValue(trace, "label"));
+    case "send_session_message":
+      return safeText(fieldValue(trace, "to"));
    case "message":
      return safeText(fieldValue(trace, "channel"));
    case "my":
@@ -301,10 +329,15 @@ function activityDetail(items: GenericToolRunItem[], family: ToolFamily, name: s
  }
 }

-function activityAside(items: GenericToolRunItem[], family: ToolFamily): string {
+function activityAside(
+  items: GenericToolRunItem[],
+  family: ToolFamily,
+  name: string,
+): string {
  const pathCount = uniqueValues(items, ["path", "file_path"]).length;
  if (pathCount > 1) return `${pathCount} files`;
  if (items.length <= 1) return "";
+  if (name === "send_session_message") return `${items.length} messages`;
  if (family === "content-search" || family === "file-search" || family === "memory") {
    return `${items.length} searches`;
  }