refactor: simplify cross-session messaging

2026-09-01 16:51:53 +03:00 · 2026-08-19 01:15:56 +08:00
parent 0e184965e8
commit 251a1ccd40
78 changed files with 1578 additions and 7569 deletions
@@ -2331,18 +2331,6 @@ function Shell({
      .map((key) => byKey.get(key))
      .filter((session): session is ChatSummary => session !== undefined);
  }, [activeTabKey, activeTabState, orderedWorkbenchTabsByKey, sessions]);
-  const collaborationSessions = useMemo(() => {
-    const nearby = workbenchPaneSessions.length > 0
-      ? workbenchPaneSessions
-      : activeSession
-        ? [activeSession]
-        : [];
-    const nearbyKeys = new Set(nearby.map((session) => session.key));
-    return [
-      ...nearby,
-      ...sessions.filter((session) => !nearbyKeys.has(session.key)),
-    ];
-  }, [activeSession, sessions, workbenchPaneSessions]);
  const paneChromeEnabled = Boolean(
    activeKey && activeSession && !temporaryChatActive && activeTabState,
  );
@@ -2759,7 +2747,7 @@ function Shell({
                    return (
                      <ThreadShell
                        session={activeSession}
-                        sessions={collaborationSessions}
+                        sessions={sessions}
                        title={headerTitle}
                        temporary={temporaryChatRequested}
                        temporaryChatIds={temporaryChatIds}
@@ -2804,7 +2792,7 @@ function Shell({
                  return (
                    <ThreadShell
                      session={paneSession}
-                      sessions={collaborationSessions}
+                      sessions={sessions}
                      title={pane.title}
                      onToggleSidebar={toggleSidebar}
                      onNewChat={onNewChat}
@@ -50,7 +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 { SessionHandleLabel } from "@/components/SessionHandleLabel";
 import { deriveTitle, relativeTime, visibleSessionPreview } from "@/lib/format";
 import {
  COLLAPSED_CHATS_VISIBLE_COUNT,
@@ -64,6 +64,7 @@ import {
  type ChatGroupLabels,
 } from "@/lib/chat-groups";
 import { deriveTemporaryChatTitle } from "@/lib/temporary-chat";
+import { sessionHandleColor } from "@/lib/session-handle";
 import {
  clearDraggedSession,
  hasDraggedSession,
@@ -120,7 +121,7 @@ function SidebarSelectionTrack({
        active ? "scale-x-100" : "scale-x-0",
      )}
      style={{
-        backgroundColor: handle ? sessionHandleColor(handle.color_slot) : "currentColor",
+        backgroundColor: handle ? sessionHandleColor(handle.id) : "currentColor",
      }}
    />
  );
@@ -130,12 +131,11 @@ 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}>
+      <SessionHandleLabel id={handle.id}>
        @{handle.name}
-      </SessionHandleHighlight>
+      </SessionHandleLabel>
    </span>
  );
 }
@@ -1,4 +1,4 @@
-import { useMemo, type ReactNode } from "react";
+import { useMemo } from "react";
 import { useTranslation } from "react-i18next";

 import {
@@ -7,12 +7,8 @@ import {
 } from "@/components/InlineTokenHighlight";
 import { useLogoFallback } from "@/hooks/useLogoFallback";
 import { logoFallbackUrls } from "@/lib/provider-brand";
-import type {
-  CliAppInfo,
-  McpPresetInfo,
-  SessionHandle,
-  SessionMention,
-} from "@/lib/types";
+import { sessionHandleColor } from "@/lib/session-handle";
+import type { CliAppInfo, McpPresetInfo, SessionMention } from "@/lib/types";
 import { cn } from "@/lib/utils";

 type CliAppMentionSegment =
@@ -22,56 +18,8 @@ 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 (
@@ -83,7 +31,6 @@ 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 (
@@ -95,15 +42,13 @@ export function mcpPresetInitials(preset: Pick<McpPresetInfo, "name" | "display_
      .join("") || preset.name.slice(0, 2).toUpperCase()
  );
 }
-
 export function splitCapabilityMentionSegments(
  value: string,
  cliApps: CliAppInfo[],
  mcpPresets: McpPresetInfo[] = [],
-  sessionHandles: SessionHandle[] = [],
-  handleSelections?: SessionHandleSelection[],
+  sessionMentions: SessionMention[] = [],
 ): CapabilityMentionSegment[] {
-  if (!value || (cliApps.length === 0 && mcpPresets.length === 0 && sessionHandles.length === 0)) {
+  if (!value || (cliApps.length === 0 && mcpPresets.length === 0 && sessionMentions.length === 0)) {
    return value ? [{ kind: "text", text: value }] : [];
  }
  const cliAppsByName = new Map(
@@ -116,13 +61,10 @@ export function splitCapabilityMentionSegments(
      .filter((preset) => preset.installed && preset.configured)
      .map((preset) => [preset.name.toLowerCase(), preset]),
  );
-  const handlesByName = new Map(
-    sessionHandles.map((handle) => [handle.name.toLowerCase(), handle]),
+  const sessionsByName = new Map(
+    sessionMentions.map((mention) => [mention.name.toLowerCase(), mention]),
  );
-  const selectedSessionNames = new Set(
-    (handleSelections ?? []).map((selection) => selection.mention.name.toLowerCase()),
-  );
-  if (cliAppsByName.size === 0 && mcpPresetsByName.size === 0 && handlesByName.size === 0) {
+  if (cliAppsByName.size === 0 && mcpPresetsByName.size === 0 && sessionsByName.size === 0) {
    return [{ kind: "text", text: value }];
  }

@@ -134,15 +76,13 @@ export function splitCapabilityMentionSegments(
    const prefix = match[1] ?? "";
    const name = match[2] ?? "";
    const key = name.toLowerCase();
+    const session = sessionsByName.get(key);
+    const app = session ? null : cliAppsByName.get(key);
+    const preset = session || app ? null : mcpPresetsByName.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) });
    }
@@ -150,51 +90,18 @@ 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 (handle) {
-      segments.push({ kind: "handle", text: value.slice(mentionStart, mentionEnd), handle });
+    } else if (session) {
+      segments.push({
+        kind: "session",
+        text: value.slice(mentionStart, mentionEnd),
+        mention: session,
+      });
    }
    cursor = mentionEnd;
  }
-  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) });
  }
-  if (cursor < value.length) segments.push({ kind: "text", text: value.slice(cursor) });
  return segments.length ? segments : [{ kind: "text", text: value }];
 }

@@ -227,42 +134,10 @@ export function CapabilityMentionToken({
      />
    );
  }
-  return <SessionHandleToken handle={segment.handle} label={segment.text} variant={variant} />;
+  return <SessionMentionToken mention={segment.mention} label={segment.text} variant={variant} />;
 }

-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/${encodeURIComponent(handle.session_key)}`}
-      className="rounded-sm underline-offset-2 hover:underline focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/60"
-      style={{ textDecorationColor: color }}
-    >
-      {token}
-    </a>
-  );
-}
-
-export function SessionReferenceToken({
+export function SessionMentionToken({
  mention,
  label,
  variant,
@@ -272,11 +147,14 @@ export function SessionReferenceToken({
  variant: "composer" | "message";
 }) {
  const testIdPrefix = variant === "composer" ? "composer" : "message";
+  const color = mention.id
+    ? sessionHandleColor(mention.id)
+    : INLINE_TOKEN_HIGHLIGHT_COLOR;
  const token = (
    <InlineTokenHighlight
-      testId={`${testIdPrefix}-session-reference-${mention.name}`}
+      testId={`${testIdPrefix}-session-mention-${mention.name}`}
      title={`Session: ${mention.title || mention.name}`}
-      color={INLINE_TOKEN_HIGHLIGHT_COLOR}
+      color={color}
      className={variant === "composer" ? "font-normal" : undefined}
    >
      {label}
@@ -287,7 +165,7 @@ export function SessionReferenceToken({
    <a
      href={`#/chat/${encodeURIComponent(mention.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: INLINE_TOKEN_HIGHLIGHT_COLOR }}
+      style={{ textDecorationColor: color }}
    >
      {token}
    </a>
@@ -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 ? { color } : undefined}
+      style={{ color }}
    >
      {children}
    </span>
@@ -8,7 +8,6 @@ import {
 } from "react";

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

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

 const loadMarkdownRenderer = () => import("@/components/MarkdownTextRenderer");
@@ -28,14 +26,12 @@ 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
@@ -43,7 +39,6 @@ const MemoizedMarkdownRenderer = memo(function MemoizedMarkdownRenderer({
      highlightCode={highlightCode}
      streaming={streaming}
      onOpenFilePreview={onOpenFilePreview}
-      sessionHandles={sessionHandles}
    >
      {source}
    </LazyMarkdownRenderer>
@@ -82,7 +77,6 @@ export function MarkdownText({
  streaming = false,
  preserveStreamingLayout = false,
  onOpenFilePreview,
-  sessionHandles,
 }: MarkdownTextProps) {
  const renderedSource = children;
  const renderPhase = streaming ? "streaming" : "complete";
@@ -114,7 +108,6 @@ export function MarkdownText({
          highlightCode={highlightCode}
          streaming={renderWithStreamingLayout}
          onOpenFilePreview={onOpenFilePreview}
-          sessionHandles={sessionHandles}
        />
      </Suspense>
    </MarkdownRendererBoundary>
@@ -16,7 +16,6 @@ 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,
@@ -35,7 +34,6 @@ 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";
@@ -46,13 +44,11 @@ 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;
@@ -281,108 +277,7 @@ function remarkCjkStrongBoundaries() {
  };
 }

-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"]> = [
+const remarkPlugins: NonNullable<StreamdownProps["remarkPlugins"]> = [
  remarkBreaks,
  remarkGfm,
  [remarkMath, { singleDollarTextMath: false }],
@@ -622,22 +517,8 @@ 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 }) {
@@ -731,30 +612,6 @@ 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 (
@@ -933,7 +790,7 @@ export default function MarkdownTextRenderer({
        );
      },
    }),
-    [highlightCode, onOpenFilePreview, handlesBySessionKey, t],
+    [highlightCode, onOpenFilePreview, t],
  );

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

 import { AttachmentTile } from "@/components/AttachmentTile";
-import { sessionHandleColor } from "@/components/CliAppMentionText";
+import { SessionHandleLabel } from "@/components/SessionHandleLabel";
 import { ImageLightbox } from "@/components/ImageLightbox";
 import { MarkdownText } from "@/components/MarkdownText";
 import { SlashCommandText } from "@/components/SlashCommandText";
@@ -37,6 +37,7 @@ import { copyTextToClipboard } from "@/lib/clipboard";
 import { fmtDateTime, formatMessageEndTime } from "@/lib/format";
 import { toMediaAttachment } from "@/lib/media";
 import { matchingSlashCommand } from "@/lib/slash-command";
+import { sessionHandleColor } from "@/lib/session-handle";
 import { parseQuotedUserMessage } from "@/lib/user-message-quote";
 import type {
  CliAppInfo,
@@ -49,7 +50,6 @@ import type {
  UIMessage,
  MessageDeliveryErrorKind,
  MessageDeliveryStatus,
-  SessionHandle,
 } from "@/lib/types";

 interface MessageBubbleProps {
@@ -63,7 +63,6 @@ interface MessageBubbleProps {
  cliApps?: CliAppInfo[];
  mcpPresets?: McpPresetInfo[];
  slashCommands?: SlashCommand[];
-  sessionDirectory?: SessionHandle[];
  onOpenFilePreview?: (path: string) => void;
  onForkFromHere?: () => void;
 }
@@ -265,47 +264,34 @@ 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 color = sessionHandleColor(handle.id);
  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"
+      data-session-message
      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}
+          <SessionHandleLabel id={handle.id}>{handleName}</SessionHandleLabel>
        </div>
        <div data-assistant-selectable="true" className="min-w-0">
          <MarkdownText
            preserveStreamingLayout
            onOpenFilePreview={onOpenFilePreview}
-            sessionHandles={sessionDirectory}
          >
            {message.content}
          </MarkdownText>
@@ -314,7 +300,6 @@ function IncomingSessionMessage({
      {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}
@@ -342,7 +327,6 @@ export function MessageBubble({
  cliApps = [],
  mcpPresets = [],
  slashCommands = [],
-  sessionDirectory = [],
  onOpenFilePreview,
  onForkFromHere,
 }: MessageBubbleProps) {
@@ -360,12 +344,11 @@ export function MessageBubble({
    return <TraceGroup message={message} />;
  }

-  if (message.role === "user" && message.sessionMessage?.direction === "incoming") {
+  if (message.role === "user" && message.sessionMessage) {
    return (
      <IncomingSessionMessage
        message={message}
        showCopyAction={showCopyAction}
-        sessionDirectory={sessionDirectory}
        onOpenFilePreview={onOpenFilePreview}
      />
    );
@@ -394,9 +377,6 @@ export function MessageBubble({
          cliApps={mentionCliApps}
          mcpPresets={mentionMcpPresets}
          sessionMentions={message.sessionMentions}
-          sessionHandles={message.sessionHandles}
-          attachedCliApps={message.cliApps}
-          attachedMcpPresets={message.mcpPresets}
        />
      </>
    ) : (
@@ -405,9 +385,6 @@ export function MessageBubble({
        cliApps={mentionCliApps}
        mcpPresets={mentionMcpPresets}
        sessionMentions={message.sessionMentions}
-        sessionHandles={message.sessionHandles}
-        attachedCliApps={message.cliApps}
-        attachedMcpPresets={message.mcpPresets}
      />
    );
    return (
@@ -525,7 +502,6 @@ export function MessageBubble({
              streaming={!!message.isStreaming}
              preserveStreamingLayout
              onOpenFilePreview={onOpenFilePreview}
-              sessionHandles={sessionDirectory}
            >
              {message.content}
            </MarkdownText>
@@ -0,0 +1,20 @@
+import type { ReactNode } from "react";
+
+import { InlineTokenHighlight } from "@/components/InlineTokenHighlight";
+import { sessionHandleColor } from "@/lib/session-handle";
+
+export function SessionHandleLabel({
+  id,
+  children,
+}: {
+  id: string;
+  children: ReactNode;
+}) {
+  return (
+    <InlineTokenHighlight
+      color={sessionHandleColor(id)}
+    >
+      {children}
+    </InlineTokenHighlight>
+  );
+}
@@ -3,24 +3,14 @@ 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,
-  SessionHandle,
-  SessionMention,
-  UICliAppAttachment,
-  UIMcpPresetAttachment,
-} from "@/lib/types";
+import type { CliAppInfo, McpPresetInfo, SessionMention } from "@/lib/types";

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

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

 function splitSkillReferenceSegments(value: string): SkillReferenceSegment[] {
@@ -60,75 +49,18 @@ function splitUserMessageSegments(
  cliApps: CliAppInfo[],
  mcpPresets: McpPresetInfo[],
  sessionMentions: SessionMention[],
-  sessionHandles: SessionHandle[],
-  attachedCliApps: UICliAppAttachment[],
-  attachedMcpPresets: UIMcpPresetAttachment[],
 ): UserMessageSegment[] {
  const segments: UserMessageSegment[] = [];
-  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);
-      }
+  for (const segment of splitCapabilityMentionSegments(
+    value,
+    cliApps,
+    mcpPresets,
+    sessionMentions,
+  )) {
+    if (segment.kind === "text") {
+      segments.push(...splitSkillReferenceSegments(segment.text));
+    } else {
+      segments.push(segment);
    }
  }
  return segments;
@@ -139,28 +71,14 @@ 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,
-    sessionHandles,
-    attachedCliApps,
-    attachedMcpPresets,
-  );
+  const segments = splitUserMessageSegments(text, cliApps, mcpPresets, sessionMentions);
  return (
    <>
      {segments.map((segment, index) => {
@@ -177,14 +95,6 @@ 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}`}
@@ -3,7 +3,7 @@ import { type ReactNode } from "react";
 import { useTranslation } from "react-i18next";

 import { Button } from "@/components/ui/button";
-import { SessionHandleHighlight } from "@/components/CliAppMentionText";
+import { SessionHandleLabel } from "@/components/SessionHandleLabel";
 import {
  Tooltip,
  TooltipContent,
@@ -85,12 +85,11 @@ export function ThreadHeader({
        ) : 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}>
+            <SessionHandleLabel id={handle.id}>
              @{handle.name}
-            </SessionHandleHighlight>
+            </SessionHandleLabel>
          </span>
        ) : null}
      </div>
@@ -4,13 +4,7 @@ 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,
-  SessionHandle,
-  SlashCommand,
-  UIMessage,
-} from "@/lib/types";
+import type { CliAppInfo, McpPresetInfo, SlashCommand, UIMessage } from "@/lib/types";

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

 import { FilePreviewAvailabilityProvider } from "@/components/FilePreviewAvailabilityContext";
 import { FilePreviewPanel } from "@/components/FilePreviewPanel";
-import { SessionHandleHighlight } from "@/components/CliAppMentionText";
+import { SessionHandleLabel } from "@/components/SessionHandleLabel";
 import { PromptNavigator } from "@/components/thread/PromptNavigator";
 import { SessionInfoPopover } from "@/components/thread/SessionInfoPopover";
 import { ThreadComposer } from "@/components/thread/ThreadComposer";
@@ -37,7 +37,6 @@ import type { CanonicalRunSnapshot, StreamError } from "@/lib/nanobot-client";
 import { inferProviderFromModelName, providerDisplayLabel } from "@/lib/provider-brand";
 import type {
  ChatSummary,
-  SessionHandle,
  SettingsPayload,
  SlashCommand,
  SkillSummary,
@@ -639,28 +638,10 @@ export function ThreadShell({
  const { t } = useTranslation();
  const chatId = session?.chatId ?? null;
  const historyKey = temporary ? null : session?.key ?? null;
-  const referenceSessions = useMemo(
-    () => sessions.filter((candidate) => (
-      candidate.key !== historyKey
-      && (
-        workspaceScope?.access_mode !== "restricted"
-        || candidate.workspaceScope?.project_path === workspaceScope.project_path
-      )
-    )),
-    [historyKey, sessions, workspaceScope],
+  const mentionSessions = useMemo(
+    () => sessions.filter((candidate) => candidate.key !== historyKey),
+    [historyKey, sessions],
  );
-  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,
@@ -1330,14 +1311,7 @@ export function ThreadShell({
      setPendingFirstTargetChatId(newId);
      return true;
    },
-    [
-      booting,
-      client,
-      localModelPreset,
-      onCreateChat,
-      withWorkspaceScope,
-      workspaceScope,
-    ],
+    [booting, client, localModelPreset, onCreateChat, withWorkspaceScope, workspaceScope],
  );

  const handleThreadSend = useCallback(
@@ -1490,8 +1464,7 @@ export function ThreadShell({
          slashCommands={availableSlashCommands}
          cliApps={cliApps}
          mcpPresets={mcpPresets}
-          sessions={referenceSessions}
-          handleSessions={handleSessions}
+          sessions={mentionSessions}
          skills={skills}
          onStop={stop}
          onTranscribeAudio={transcribeAudio}
@@ -1538,8 +1511,7 @@ export function ThreadShell({
          slashCommands={availableSlashCommands}
          cliApps={cliApps}
          mcpPresets={mcpPresets}
-          sessions={referenceSessions}
-          handleSessions={handleSessions}
+          sessions={mentionSessions}
          skills={skills}
          surfaceRef={composerSurfaceRef}
          onTranscribeAudio={transcribeAudio}
@@ -1609,18 +1581,15 @@ export function ThreadShell({
      <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}>
+              <SessionHandleLabel id={session.handle.id}>
                @{session.handle.name}
-              </SessionHandleHighlight>
+              </SessionHandleLabel>
            </span>
          </div>
        ) : null}
@@ -1643,7 +1612,6 @@ export function ThreadShell({
            showScrollToBottomButton={!!session}
            cliApps={cliApps}
            mcpPresets={mcpPresets}
-            sessionDirectory={sessionDirectory}
            slashCommands={availableSlashCommands}
            forkBoundaryMessageCount={forkBoundaryMessageCount}
            hasMoreBefore={hasMoreBefore}
@@ -26,13 +26,7 @@ import {
  promptTop,
 } from "@/components/thread/promptNavigation";
 import { cn } from "@/lib/utils";
-import type {
-  CliAppInfo,
-  McpPresetInfo,
-  SessionHandle,
-  SlashCommand,
-  UIMessage,
-} from "@/lib/types";
+import type { CliAppInfo, McpPresetInfo, SlashCommand, UIMessage } from "@/lib/types";

 export interface ThreadViewportHandle {
  jumpToUserPrompt: (promptId: string) => void;
@@ -56,7 +50,6 @@ interface ThreadViewportProps {
  cliApps?: CliAppInfo[];
  mcpPresets?: McpPresetInfo[];
  slashCommands?: SlashCommand[];
-  sessionDirectory?: SessionHandle[];
  forkBoundaryMessageCount?: number | null;
  hasMoreBefore?: boolean;
  loadingOlder?: boolean;
@@ -76,7 +69,6 @@ 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;

@@ -112,6 +104,11 @@ 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(
@@ -119,11 +116,6 @@ 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<
@@ -193,7 +185,6 @@ export const ThreadViewport = forwardRef<ThreadViewportHandle, ThreadViewportPro
  cliApps = [],
  mcpPresets = [],
  slashCommands = [],
-  sessionDirectory = EMPTY_SESSION_DIRECTORY,
  forkBoundaryMessageCount = null,
  hasMoreBefore = false,
  loadingOlder = false,
@@ -771,7 +762,6 @@ export const ThreadViewport = forwardRef<ThreadViewportHandle, ThreadViewportPro
                  cliApps={cliApps}
                  mcpPresets={mcpPresets}
                  slashCommands={slashCommands}
-                  sessionDirectory={sessionDirectory}
                  forkBoundaryMessageCount={visibleForkBoundaryMessageCount}
                  onOpenFilePreview={onOpenFilePreview}
                  onForkFromMessage={onForkFromMessage}
@@ -15,8 +15,6 @@ export interface ToolField {
    | "key"
    | "label"
    | "name"
-    | "to"
-    | "expect_reply"
    | "channel"
    | "chat_id"
    | "session_id"
@@ -121,7 +119,7 @@ export function describeGenericToolRun(items: GenericToolRunItem[]): GenericTool
    status,
    label: activityLabel(family, status, collected, name, items),
    detail: activityDetail(items, family, name),
-    aside: activityAside(items, family, name),
+    aside: activityAside(items, family),
  };
 }

@@ -170,7 +168,6 @@ function safeFields(args: unknown): ToolField[] {
    "key",
    "label",
    "name",
-    "to",
    "channel",
    "chat_id",
    "session_id",
@@ -181,17 +178,6 @@ 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;
 }

@@ -240,18 +226,6 @@ 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":
@@ -307,8 +281,6 @@ 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":
@@ -329,15 +301,10 @@ function activityDetail(items: GenericToolRunItem[], family: ToolFamily, name: s
  }
 }

-function activityAside(
-  items: GenericToolRunItem[],
-  family: ToolFamily,
-  name: string,
-): string {
+function activityAside(items: GenericToolRunItem[], family: ToolFamily): 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`;
  }
@@ -33,14 +33,8 @@
    --input: 40 8% 90.5%;
    --ring: 0 0% 3.9%;
    --inline-token-highlight: #ef8e30;
-    --session-handle-0: #b45f36;
-    --session-handle-1: #9b6b16;
-    --session-handle-2: #3f7a4f;
-    --session-handle-3: #267b78;
-    --session-handle-4: #3c6fa8;
-    --session-handle-5: #655fb0;
-    --session-handle-6: #98558f;
-    --session-handle-7: #a54f62;
+    --session-handle-lightness: 0.5;
+    --session-handle-chroma: 0.12;
    --temporary-control-active: #ef8e30;
    --temporary-accent: 24 95% 53%;
    --temporary-foreground: 17 88% 32%;
@@ -89,14 +83,8 @@
    --input: var(--border);
    --ring: 0 0% 83.1%;
    --inline-token-highlight: #ef8e30;
-    --session-handle-0: #e58a62;
-    --session-handle-1: #d2a44d;
-    --session-handle-2: #73b985;
-    --session-handle-3: #55b8b2;
-    --session-handle-4: #72a5dc;
-    --session-handle-5: #9a91e3;
-    --session-handle-6: #cf83c5;
-    --session-handle-7: #dc7e91;
+    --session-handle-lightness: 0.75;
+    --session-handle-chroma: 0.11;
    --temporary-control-active: #ef8e30;
    --temporary-accent: 24 95% 53%;
    --temporary-foreground: 32 98% 73%;
@@ -33,7 +33,6 @@ import type {
  OutboundCliAppMention,
  OutboundMcpPresetMention,
  OutboundMedia,
-  SessionHandle,
  SessionMention,
  GoalStateWsPayload,
  MessageDeliveryStatus,
@@ -170,7 +169,6 @@ export interface SendOptions {
  cliApps?: OutboundCliAppMention[];
  mcpPresets?: OutboundMcpPresetMention[];
  sessionMentions?: SessionMention[];
-  sessionHandles?: SessionHandle[];
  quotedContext?: string;
  workspaceScope?: WorkspaceScopePayload | null;
  sideChannel?: boolean;
@@ -190,7 +188,6 @@ function eventExtendsModelActivity(ev: InboundEvent): boolean {
    ev.event === "delta"
    || ev.event === "reasoning_delta"
    || ev.event === "file_edit"
-    || ev.event === "session_message"
  ) return true;
  return ev.event === "message"
    && (ev.kind === "tool_hint" || ev.kind === "progress" || ev.kind === "reasoning");
@@ -221,31 +218,27 @@ function transitionTurnDelivery(
  return changed ? next : messages;
 }

-function appendLiveSessionMessage(
+function appendProjectedSessionInput(
  messages: UIMessage[],
-  event: Extract<InboundEvent, { event: "session_message" }>,
+  event: Extract<InboundEvent, { event: "user_message" }>,
 ): UIMessage[] {
-  const messageId = event.session_message?.message_id?.trim();
-  if (!messageId || event.session_message.direction !== "incoming") return messages;
+  const sessionMessage = event.provenance?.session_message;
+  const messageId = sessionMessage?.message_id?.trim();
+  if (!sessionMessage || !messageId) return messages;
  if (messages.some((message) => message.sessionMessage?.message_id === messageId)) return messages;

  const row: UIMessage = {
    id: `session-message:${messageId}`,
    role: "user",
    content: event.text,
-    createdAt: Number.isFinite(event.created_at_ms) ? event.created_at_ms : Date.now(),
-    sessionMessage: event.session_message,
+    createdAt: typeof event.created_at_ms === "number"
+      && Number.isFinite(event.created_at_ms)
+      ? event.created_at_ms
+      : Date.now(),
+    sessionMessage,
    ...turnFieldsFromEvent(event, "user"),
  };
-  const sameTurnIndex = event.turn_id
-    ? messages.findIndex((message) => message.turnId === event.turn_id)
-    : -1;
-  if (sameTurnIndex < 0) return [...messages, row];
-  return [
-    ...messages.slice(0, sameTurnIndex),
-    row,
-    ...messages.slice(sameTurnIndex),
-  ];
+  return [...messages, row];
 }

 export function useNanobotStream(
@@ -675,18 +668,6 @@ export function useNanobotStream(
    });
  }, [cancelStreamEndTimer, client]);

-  useEffect(() => {
-    return client.onRunStatus((updatedChatId, startedAt) => {
-      if (updatedChatId !== chatId) return;
-      // Canonical HTTP reconciliation can settle a turn before its delayed
-      // WebSocket completion frame reaches this mounted thread. The client
-      // then fences that duplicate frame, so keep the pane-local timer in
-      // sync with the client's authoritative per-chat run projection.
-      setRunStartedAt(startedAt);
-      if (startedAt !== null) setIsStreaming(true);
-    });
-  }, [chatId, client]);
-
  // Reset local state when switching chats. Do not reset on every
  // ``initialMessages`` update: a brand-new chat can receive an empty/404
  // history response after the optimistic first message has already rendered.
@@ -752,6 +733,13 @@ export function useNanobotStream(
      }
      if (ev.event === "message_accepted") return;
      if (ev.event === "user_message") {
+        if (ev.provenance?.session_message) {
+          flushPendingStreamEvents({ closeAnswerSegment: true });
+          clearActivitySegment();
+          setIsStreaming(true);
+          setMessages((prev) => appendProjectedSessionInput(prev, ev));
+          return;
+        }
        setMessages((prev) => {
          if (ev.turn_id && prev.some((message) => (
            message.role === "user" && message.turnId === ev.turn_id
@@ -766,7 +754,10 @@ export function useNanobotStream(
              turnPhase: "user",
              turnSeq: 0,
              deliveryStatus: "accepted",
-              createdAt: Date.now(),
+              createdAt: typeof ev.created_at_ms === "number"
+                && Number.isFinite(ev.created_at_ms)
+                ? ev.created_at_ms
+                : Date.now(),
              ...(ev.media_urls?.length ? { media: ev.media_urls } : {}),
              ...(ev.cli_apps?.length ? { cliApps: ev.cli_apps } : {}),
              ...(ev.mcp_presets?.length ? { mcpPresets: ev.mcp_presets } : {}),
@@ -844,20 +835,12 @@ export function useNanobotStream(

      const shouldCloseAnswerBeforeEvent =
        ev.event === "file_edit"
-        || ev.event === "session_message"
        || (
          ev.event === "message"
          && (ev.kind === "tool_hint" || ev.kind === "progress")
        );
      flushPendingStreamEvents({ closeAnswerSegment: shouldCloseAnswerBeforeEvent });

-      if (ev.event === "session_message") {
-        clearActivitySegment();
-        setIsStreaming(true);
-        setMessages((prev) => appendLiveSessionMessage(prev, ev));
-        return;
-      }
-
      if (ev.event === "reasoning_end") {
        if (suppressStreamUntilTurnEndRef.current) return;
        setMessages((prev) => closeReasoningStream(prev, Date.now()));
@@ -1188,9 +1171,6 @@ export function useNanobotStream(
            ...(options?.sessionMentions?.length
              ? { sessionMentions: options.sessionMentions }
              : {}),
-            ...(options?.sessionHandles?.length
-              ? { sessionHandles: options.sessionHandles }
-              : {}),
          },
        ];
      });
@@ -1180,6 +1180,7 @@
      "placeholderStreaming": "Model is responding…",
      "inputAria": "Message input",
      "sendHint": "Enter to send · Shift+Enter for newline",
+      "runRuntimeTitle": "Running · {{elapsed}}",
      "goalStateStrip": "Goal · {{label}}",
      "goalStateFallback": "Goal",
      "goalStateExpandAria": "Show full goal",
@@ -1323,7 +1324,9 @@
        "cliDescription": "Use @{{name}} as a local CLI app",
        "mcpDescription": "Use @{{name}} as an MCP server",
        "cliTitle": "CLI app: {{name}}",
-        "mcpTitle": "MCP server: {{name}}"
+        "mcpTitle": "MCP server: {{name}}",
+        "sessionBadge": "Nanobot conversation",
+        "sessionDescription": "Reference @{{name}} as a previous chat"
      },
      "encoding": "Encoding…",
      "remove": "Remove attachment",
@@ -1167,6 +1167,7 @@
      "placeholderStreaming": "El modelo está respondiendo…",
      "inputAria": "Entrada de mensaje",
      "sendHint": "Enter para enviar · Shift+Enter para nueva línea",
+      "runRuntimeTitle": "En ejecución · {{elapsed}}",
      "goalStateStrip": "Objetivo · {{label}}",
      "goalStateFallback": "Objetivo",
      "goalStateExpandAria": "Ver objetivo completo",
@@ -1326,7 +1327,9 @@
        "cliDescription": "Usar @{{name}} como aplicación CLI local",
        "mcpDescription": "Usar @{{name}} como servidor MCP",
        "cliTitle": "Aplicación CLI: {{name}}",
-        "mcpTitle": "Servidor MCP: {{name}}"
+        "mcpTitle": "Servidor MCP: {{name}}",
+        "sessionBadge": "Conversación de Nanobot",
+        "sessionDescription": "Referenciar @{{name}} como chat anterior"
      },
      "workspace": {
        "accessAria": "Modo de acceso al espacio de trabajo",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "Le modèle est en train de répondre…",
      "inputAria": "Champ de message",
      "sendHint": "Entrée pour envoyer · Maj+Entrée pour un retour à la ligne",
+      "runRuntimeTitle": "Exécution · {{elapsed}}",
      "goalStateStrip": "Objectif · {{label}}",
      "goalStateFallback": "Objectif",
      "goalStateExpandAria": "Afficher l’objectif complet",
@@ -1325,7 +1326,9 @@
        "cliDescription": "Utiliser @{{name}} comme application CLI locale",
        "mcpDescription": "Utiliser @{{name}} comme serveur MCP",
        "cliTitle": "Application CLI : {{name}}",
-        "mcpTitle": "Serveur MCP : {{name}}"
+        "mcpTitle": "Serveur MCP : {{name}}",
+        "sessionBadge": "Conversation Nanobot",
+        "sessionDescription": "Référencer @{{name}} comme discussion précédente"
      },
      "workspace": {
        "accessAria": "Mode d’accès à l’espace de travail",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "Model sedang merespons…",
      "inputAria": "Input pesan",
      "sendHint": "Enter untuk kirim · Shift+Enter untuk baris baru",
+      "runRuntimeTitle": "Berjalan · {{elapsed}}",
      "goalStateStrip": "Tujuan · {{label}}",
      "goalStateFallback": "Tujuan",
      "goalStateExpandAria": "Lihat tujuan lengkap",
@@ -1325,7 +1326,9 @@
        "cliDescription": "Gunakan @{{name}} sebagai aplikasi CLI lokal",
        "mcpDescription": "Gunakan @{{name}} sebagai server MCP",
        "cliTitle": "Aplikasi CLI: {{name}}",
-        "mcpTitle": "Server MCP: {{name}}"
+        "mcpTitle": "Server MCP: {{name}}",
+        "sessionBadge": "Percakapan Nanobot",
+        "sessionDescription": "Referensikan @{{name}} sebagai chat sebelumnya"
      },
      "workspace": {
        "accessAria": "Mode akses ruang kerja",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "モデルが応答しています…",
      "inputAria": "メッセージ入力欄",
      "sendHint": "Enter で送信 · Shift+Enter で改行",
+      "runRuntimeTitle": "実行中 · {{elapsed}}",
      "goalStateStrip": "目標 · {{label}}",
      "goalStateFallback": "目標",
      "goalStateExpandAria": "目標の全文を表示",
@@ -1325,7 +1326,9 @@
        "cliDescription": "@{{name}} をローカル CLI アプリとして使用",
        "mcpDescription": "@{{name}} を MCP サーバーとして使用",
        "cliTitle": "CLI アプリ: {{name}}",
-        "mcpTitle": "MCP サーバー: {{name}}"
+        "mcpTitle": "MCP サーバー: {{name}}",
+        "sessionBadge": "Nanobot の会話",
+        "sessionDescription": "@{{name}} を過去のチャットとして参照"
      },
      "workspace": {
        "accessAria": "ワークスペースのアクセスモード",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "모델이 응답 중입니다…",
      "inputAria": "메시지 입력",
      "sendHint": "Enter로 전송 · Shift+Enter로 줄바꿈",
+      "runRuntimeTitle": "실행 중 · {{elapsed}}",
      "goalStateStrip": "목표 · {{label}}",
      "goalStateFallback": "목표",
      "goalStateExpandAria": "전체 목표 보기",
@@ -1325,7 +1326,9 @@
        "cliDescription": "@{{name}}을 로컬 CLI 앱으로 사용",
        "mcpDescription": "@{{name}}을 MCP 서버로 사용",
        "cliTitle": "CLI 앱: {{name}}",
-        "mcpTitle": "MCP 서버: {{name}}"
+        "mcpTitle": "MCP 서버: {{name}}",
+        "sessionBadge": "Nanobot 대화",
+        "sessionDescription": "@{{name}}을 이전 채팅으로 참조"
      },
      "workspace": {
        "accessAria": "작업공간 접근 모드",
@@ -1180,6 +1180,7 @@
      "placeholderStreaming": "O modelo está respondendo…",
      "inputAria": "Campo de mensagem",
      "sendHint": "Enter para enviar · Shift+Enter para nova linha",
+      "runRuntimeTitle": "Executando · {{elapsed}}",
      "goalStateStrip": "Objetivo · {{label}}",
      "goalStateFallback": "Objetivo",
      "goalStateExpandAria": "Mostrar objetivo completo",
@@ -1323,7 +1324,9 @@
        "cliDescription": "Usar @{{name}} como aplicativo CLI local",
        "mcpDescription": "Usar @{{name}} como servidor MCP",
        "cliTitle": "Aplicativo CLI: {{name}}",
-        "mcpTitle": "Servidor MCP: {{name}}"
+        "mcpTitle": "Servidor MCP: {{name}}",
+        "sessionBadge": "Conversa do Nanobot",
+        "sessionDescription": "Referenciar @{{name}} como chat anterior"
      },
      "encoding": "Codificando…",
      "remove": "Remover anexo",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "Mô hình đang trả lời…",
      "inputAria": "Ô nhập tin nhắn",
      "sendHint": "Enter để gửi · Shift+Enter để xuống dòng",
+      "runRuntimeTitle": "Đang chạy · {{elapsed}}",
      "goalStateStrip": "Mục tiêu · {{label}}",
      "goalStateFallback": "Mục tiêu",
      "goalStateExpandAria": "Xem đầy đủ mục tiêu",
@@ -1325,7 +1326,9 @@
        "cliDescription": "Dùng @{{name}} như ứng dụng CLI cục bộ",
        "mcpDescription": "Dùng @{{name}} như máy chủ MCP",
        "cliTitle": "Ứng dụng CLI: {{name}}",
-        "mcpTitle": "Máy chủ MCP: {{name}}"
+        "mcpTitle": "Máy chủ MCP: {{name}}",
+        "sessionBadge": "Cuộc trò chuyện Nanobot",
+        "sessionDescription": "Tham chiếu @{{name}} như cuộc trò chuyện trước"
      },
      "workspace": {
        "accessAria": "Chế độ truy cập không gian làm việc",
@@ -1180,6 +1180,7 @@
      "placeholderStreaming": "模型正在回复…",
      "inputAria": "消息输入框",
      "sendHint": "Enter 发送 · Shift+Enter 换行",
+      "runRuntimeTitle": "运行中 · {{elapsed}}",
      "goalStateStrip": "目标 · {{label}}",
      "goalStateFallback": "目标",
      "goalStateExpandAria": "查看完整目标",
@@ -1322,7 +1323,9 @@
        "cliDescription": "使用 @{{name}} 调用本地 CLI",
        "mcpDescription": "使用 @{{name}} 调用 MCP 服务",
        "cliTitle": "CLI 应用：{{name}}",
-        "mcpTitle": "MCP 服务：{{name}}"
+        "mcpTitle": "MCP 服务：{{name}}",
+        "sessionBadge": "Nanobot 对话",
+        "sessionDescription": "引用历史会话 @{{name}}"
      },
      "encoding": "处理中…",
      "remove": "移除附件",
@@ -1166,6 +1166,7 @@
      "placeholderStreaming": "模型正在回覆…",
      "inputAria": "訊息輸入框",
      "sendHint": "Enter 送出 · Shift+Enter 換行",
+      "runRuntimeTitle": "執行中 · {{elapsed}}",
      "goalStateStrip": "目標 · {{label}}",
      "goalStateFallback": "目標",
      "goalStateExpandAria": "檢視完整目標",
@@ -1325,7 +1326,9 @@
        "cliDescription": "將 @{{name}} 作為本機 CLI 應用程式使用",
        "mcpDescription": "將 @{{name}} 作為 MCP 伺服器使用",
        "cliTitle": "CLI 應用程式：{{name}}",
-        "mcpTitle": "MCP 伺服器：{{name}}"
+        "mcpTitle": "MCP 伺服器：{{name}}",
+        "sessionBadge": "Nanobot 對話",
+        "sessionDescription": "引用先前的對話 @{{name}}"
      },
      "workspace": {
        "accessAria": "工作區存取模式",
@@ -23,7 +23,7 @@ import type {
  ProviderOAuthLoginResult,
  ProviderSettingsUpdate,
  SessionDeleteResult,
-  SessionListHandle,
+  SessionHandle,
  SessionAutomationsPayload,
  SettingsPayload,
  SettingsUpdate,
@@ -167,20 +167,17 @@ function splitKey(key: string): { channel: string; chatId: string } {
  return { channel: key.slice(0, idx), chatId: key.slice(idx + 1) };
 }

-function normalizeSessionListHandle(value: unknown): SessionListHandle | null {
+function normalizeSessionHandle(value: unknown): SessionHandle | null {
  if (!value || typeof value !== "object") return null;
-  const handle = value as Partial<SessionListHandle>;
+  const handle = value as Partial<SessionHandle>;
  const id = typeof handle.id === "string" ? handle.id.trim() : "";
  const name = typeof handle.name === "string" ? handle.name.trim() : "";
  if (
    !/^handle_[a-f0-9]{32}$/i.test(id)
    || !name
    || !/^[\p{L}\p{N}_-]+$/u.test(name)
-    || !Number.isInteger(handle.color_slot)
-    || (handle.color_slot ?? -1) < 0
-    || (handle.color_slot ?? 8) >= 8
  ) return null;
-  return { id, name, color_slot: handle.color_slot as number };
+  return { id, name };
 }

 export async function listSessions(
@@ -196,7 +193,7 @@ export async function listSessions(
    model_preset?: string | null;
    run_started_at?: number | null;
    workspace_scope?: WorkspaceScopePayload | null;
-    handle?: SessionListHandle | null;
+    handle?: SessionHandle | null;
  };
  const body = await request<{ sessions: Row[] }>(
    `${base}/api/sessions`,
@@ -205,8 +202,7 @@ export async function listSessions(
    API_READ_TIMEOUT_MS,
  );
  return body.sessions.map((s) => {
-    const rawSession = normalizeSessionListHandle(s.handle);
-    const handle = rawSession ? { ...rawSession, session_key: s.key } : null;
+    const handle = normalizeSessionHandle(s.handle);
    return {
      key: s.key,
      ...splitKey(s.key),
@@ -5,7 +5,6 @@ import type {
  OutboundCliAppMention,
  OutboundMcpPresetMention,
  OutboundMedia,
-  SessionHandle,
  SessionMention,
  SidebarStatePayload,
  GoalStateWsPayload,
@@ -196,7 +195,7 @@ export class NanobotClient {
  private knownChats = new Set<string>();
  /** Temporary chats are connection-owned and intentionally not reattached. */
  private temporaryChatIds = new Set<string>();
-  /** Per-chat run projection, started optimistically and reconciled by lifecycle events. */
+  /** Wall-clock run strip: updated from ``goal_status`` even with no ``onChat`` subscriber. */
  private runStartedAtByChatId = new Map<string, number>();
  /** Per-turn clocks let a rejected newer turn fall back without borrowing its timer. */
  private runStartedAtByTurnKey = new Map<string, number>();
@@ -538,14 +537,6 @@ export class NanobotClient {
    }
  }

-  private startRunLocally(chatId: string, turnId: string): void {
-    const startedAt = Date.now() / 1000;
-    this.runStartedAtByTurnKey.set(this.runSendKey(chatId, turnId), startedAt);
-    const previous = this.runStartedAtByChatId.get(chatId);
-    this.runStartedAtByChatId.set(chatId, startedAt);
-    if (previous !== startedAt) this.emitRunStatus(chatId, startedAt);
-  }
-
  private settleRunTurn(chatId: string, turnId?: string): void {
    if (!turnId) return;
    this.clearPendingMessageSend(chatId, turnId);
@@ -725,7 +716,7 @@ export class NanobotClient {
    }
  }

-  private recordRunStatus(chatId: string, ev: InboundEvent): void {
+  private recordGoalStatusForRunStrip(chatId: string, ev: InboundEvent): void {
    if (ev.event === "turn_end") {
      this.recordRunCompletion(chatId, ev.turn_id);
      return;
@@ -976,7 +967,6 @@ export class NanobotClient {
      cliApps?: OutboundCliAppMention[];
      mcpPresets?: OutboundMcpPresetMention[];
      sessionMentions?: SessionMention[];
-      sessionHandles?: SessionHandle[];
      quotedContext?: string;
      workspaceScope?: WorkspaceScopePayload | null;
      turnId?: string;
@@ -996,9 +986,6 @@ export class NanobotClient {
      ...(options?.sessionMentions?.length
        ? { session_mentions: options.sessionMentions }
        : {}),
-      ...(options?.sessionHandles?.length
-        ? { session_handles: options.sessionHandles }
-        : {}),
      ...(options?.quotedContext?.trim() ? { quoted_context: options.quotedContext.trim() } : {}),
      ...(options?.workspaceScope ? { workspace_scope: options.workspaceScope } : {}),
      ...(options?.turnId ? { turn_id: options.turnId } : {}),
@@ -1017,10 +1004,7 @@ export class NanobotClient {
    }
    if (options?.turnId && !isSystemCommandTurnId(options.turnId)) {
      const startsNewRun = options.startsNewRun !== false;
-      if (startsNewRun) {
-        this.advanceRunGeneration(chatId, options.turnId);
-        this.startRunLocally(chatId, options.turnId);
-      }
+      if (startsNewRun) this.advanceRunGeneration(chatId, options.turnId);
      this.trackPendingMessageSend(chatId, options.turnId, startsNewRun);
    }
    this.queueSend(frame);
@@ -1256,7 +1240,7 @@ export class NanobotClient {
    if (chatId) {
      if (this.isCanonicalCompletedTurnEvent(chatId, parsed)) return;
      const supersededRunCompletion = this.isSupersededRunCompletion(chatId, parsed);
-      this.recordRunStatus(chatId, parsed);
+      this.recordGoalStatusForRunStrip(chatId, parsed);
      if (supersededRunCompletion) return;
      this.recordGoalStateSnapshot(chatId, parsed);
      this.dispatch(chatId, parsed);
@@ -0,0 +1,9 @@
+export function sessionHandleColor(handleId: string): string {
+  let hash = 2166136261;
+  for (const char of handleId) {
+    hash ^= char.codePointAt(0) ?? 0;
+    hash = Math.imul(hash, 16777619);
+  }
+  const hue = (hash >>> 0) % 360;
+  return `oklch(var(--session-handle-lightness) var(--session-handle-chroma) ${hue})`;
+}
@@ -66,8 +66,6 @@ export interface UIMessage {
  mcpPresets?: UIMcpPresetAttachment[];
  /** Persisted sessions explicitly referenced by this user turn. */
  sessionMentions?: SessionMention[];
-  /** Active session handles structurally selected by this user turn. */
-  sessionHandles?: SessionHandle[];
  /** Assistant turn: accumulated model reasoning / thinking text. Built up
   * incrementally from ``reasoning_delta`` frames; finalized when
   * ``reasoning_end`` arrives. */
@@ -114,29 +112,24 @@ export interface UIMcpPresetAttachment {
 }

 export interface SessionMention {
-  /** Text token inserted in the composer, without the leading #. */
+  /** Stable public identity. Older transcript rows may not include it. */
+  id?: string;
+  /** Text token inserted in the composer, without the leading @. */
  name: string;
  /** Stable persisted-session identifier used by read_session. */
  session_key: string;
  title: string;
 }

-/** Exact public handle DTO returned by the session-list endpoint. */
-export interface SessionListHandle {
+/** Stable public handle returned by the session-list endpoint. */
+export interface SessionHandle {
  id: string;
  name: string;
-  color_slot: number;
-}
-
-/** Public session handle enriched with its UI navigation target. */
-export interface SessionHandle extends SessionListHandle {
-  session_key: string;
 }

 export interface UISessionMessage {
-  direction: "incoming" | "outgoing";
  message_id: string;
-  session: SessionListHandle;
+  session: SessionHandle;
 }

 export interface SessionAutomationJob {
@@ -1249,10 +1242,12 @@ export type InboundEvent =
      active_turn_id?: string;
      starts_turn: boolean;
      started_at?: number;
+      created_at_ms?: number;
      media_urls?: UIMediaAttachment[];
      cli_apps?: UICliAppAttachment[];
      mcp_presets?: UIMcpPresetAttachment[];
      session_mentions?: SessionMention[];
+      provenance?: { session_message?: UISessionMessage };
    }
  | ({
      event: "message";
@@ -1272,13 +1267,6 @@ export type InboundEvent =
      /** Optional structured payload on progress frames (channel-specific). */
      agent_ui?: AgentUIBlob;
    } & InboundTurnMetadata)
-  | ({
-      event: "session_message";
-      chat_id: string;
-      text: string;
-      created_at_ms: number;
-      session_message: UISessionMessage;
-    } & InboundTurnMetadata)
  | ({
      event: "file_edit";
      chat_id: string;
@@ -1473,7 +1461,6 @@ export type Outbound =
      cli_apps?: OutboundCliAppMention[];
      mcp_presets?: OutboundMcpPresetMention[];
      session_mentions?: SessionMention[];
-      session_handles?: SessionHandle[];
      quoted_context?: string;
      workspace_scope?: WorkspaceScopePayload;
      turn_id?: string;
@@ -1049,7 +1049,7 @@ describe("webui API helpers", () => {
    );
  });

-  it("maps title-free handle handles", async () => {
+  it("maps generated session titles from the sessions list", async () => {
    vi.mocked(fetch).mockResolvedValueOnce({
      ok: true,
      json: async () => ({
@@ -1062,9 +1062,8 @@ describe("webui API helpers", () => {
            model_preset: "fast",
            run_started_at: 1_700_000_000,
            handle: {
-              id: "handle_1234567890abcdef1234567890abcdef",
-              name: "webui-review",
-              color_slot: 5,
+              id: "handle_0123456789abcdef0123456789abcdef",
+              name: "mira-0123456789",
            },
          },
        ],
@@ -1079,38 +1078,13 @@ describe("webui API helpers", () => {
        modelPreset: "fast",
        runStartedAt: 1_700_000_000,
        handle: {
-          id: "handle_1234567890abcdef1234567890abcdef",
-          name: "webui-review",
-          color_slot: 5,
-          session_key: "websocket:chat-1",
+          id: "handle_0123456789abcdef0123456789abcdef",
+          name: "mira-0123456789",
        },
      },
    ]);
  });

-  it("rejects malformed session-list handle DTOs instead of trusting enriched fields", async () => {
-    vi.mocked(fetch).mockResolvedValueOnce({
-      ok: true,
-      json: async () => ({
-        sessions: [
-          {
-            key: "websocket:chat-1",
-            created_at: null,
-            updated_at: null,
-            handle: {
-              id: "handle_1234567890abcdef1234567890abcdef",
-              name: "valid-handle",
-              color_slot: 8,
-              session_key: "websocket:attacker-controlled",
-            },
-          },
-        ],
-      }),
-    } as Response);
-
-    await expect(listSessions("tok")).resolves.toMatchObject([{ handle: null }]);
-  });
-
  it("maps slash command metadata from the commands endpoint", async () => {
    vi.mocked(fetch).mockResolvedValueOnce({
      ok: true,
@@ -519,7 +519,7 @@ describe("App layout", () => {

    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
    const firstMessage = "keep this first turn visible";
-    fireEvent.change(screen.getByRole("combobox", { name: "Message input" }), {
+    fireEvent.change(screen.getByRole("textbox", { name: "Message input" }), {
      target: { value: firstMessage },
    });
    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
@@ -3375,7 +3375,7 @@ describe("App layout", () => {
      .toEqual(["Alpha", "New topic"]);

    const activeComposer = screen.getByTestId("active-pane-composer");
-    const paneInput = within(activeComposer).getByRole("combobox", {
+    const paneInput = within(activeComposer).getByRole("textbox", {
      name: "Message New topic",
    });
    expect(paneInput).toHaveClass("min-h-[50px]");
@@ -66,104 +66,6 @@ describe("ChatList", () => {
    expect(onTogglePin).toHaveBeenCalledWith("websocket:review");
  });

-  it("keeps each handle handle visible beside its conversation title", () => {
-    render(
-      <ChatList
-        sessions={[session({
-          chatId: "review",
-          title: "Review the patch",
-          handle: {
-            id: "handle_1234",
-            name: "mira",
-            color_slot: 3,
-            session_key: "websocket:review",
-          },
-        })]}
-        activeKey="websocket:review"
-        onSelect={vi.fn()}
-        onRequestDelete={vi.fn()}
-        onTogglePin={vi.fn()}
-        onRequestRename={vi.fn()}
-        onToggleArchive={vi.fn()}
-      />,
-    );
-
-    const conversation = screen.getByRole("button", {
-      name: "@mira Review the patch",
-    });
-    expect(conversation).toHaveTextContent("Review the patch");
-    expect(conversation).toHaveTextContent("@mira");
-    expect(conversation.querySelector("[data-sidebar-handle-handle]"))
-      .toHaveClass("max-w-20", "shrink-0");
-    const handle = conversation.querySelector("[data-sidebar-handle-handle]");
-    expect(handle?.querySelector("[aria-hidden]")).toBeNull();
-    const decoration = handle?.querySelector("span[style*='border-bottom-color']");
-    expect(decoration?.getAttribute("style"))
-      .toContain("var(--session-handle-3)");
-    expect(decoration?.querySelector("[data-testid], .text-foreground"))
-      .toHaveClass("text-foreground");
-    const selectionTrack = conversation.querySelector("[data-sidebar-selection-track]");
-    expect(selectionTrack).toHaveAttribute("data-active", "true");
-    expect(selectionTrack?.getAttribute("style")).toContain("var(--session-handle-3)");
-  });
-
-  it("keeps aligned handle handles when conversations become grouped panes", () => {
-    const mira = {
-      id: "handle_1234",
-      name: "mira",
-      color_slot: 3,
-      session_key: "websocket:root",
-    };
-    const nora = {
-      id: "handle_5678",
-      name: "nora",
-      color_slot: 5,
-      session_key: "websocket:child",
-    };
-    render(
-      <ChatList
-        sessions={[session({
-          key: "tab:group",
-          chatId: "workbench-tab:group",
-          title: "Grouped work",
-        })]}
-        activeKey="websocket:root"
-        paneGroups={{
-          "tab:group": {
-            tabKey: "tab:group",
-            title: "Grouped work",
-            activePaneKey: "websocket:root",
-            visible: true,
-            panes: [
-              { key: "websocket:root", chatId: "root", title: "Short", handle: mira },
-              {
-                key: "websocket:child",
-                chatId: "child",
-                title: "A much longer conversation title",
-                handle: nora,
-              },
-            ],
-          },
-        }}
-        onSelect={vi.fn()}
-        onRequestDelete={vi.fn()}
-        onTogglePin={vi.fn()}
-        onRequestRename={vi.fn()}
-        onToggleArchive={vi.fn()}
-      />,
-    );
-
-    const root = screen.getByRole("button", { name: "@mira Short" });
-    const child = screen.getByRole("button", {
-      name: "@nora A much longer conversation title",
-    });
-    expect(root).toHaveTextContent("@mira");
-    expect(child).toHaveTextContent("@nora");
-    for (const handle of document.querySelectorAll("[data-sidebar-handle-handle]")) {
-      expect(handle).toHaveClass("max-w-20", "shrink-0");
-    }
-  });
-
  it("keeps tab grouping out of drag protocols while exposing inactive panes as mention sources", () => {
    render(
      <ChatList
@@ -1080,10 +982,10 @@ describe("ChatList", () => {

    const activeButton = screen.getByRole("button", { name: "Active topic" });
    expect(activeButton).toHaveAttribute("aria-current", "page");
-    const activeTrack = activeButton.querySelector("[data-sidebar-selection-track]");
-    expect(activeTrack)
+    expect(activeButton.querySelector("[data-sidebar-selection-track]"))
      .toHaveClass("origin-left", "scale-x-100", "transition-transform");
-    expect(activeTrack?.getAttribute("style")).toContain("currentcolor");
+    expect(activeButton.querySelector("[data-sidebar-selection-track]"))
+      .toHaveStyle({ backgroundColor: "currentColor" });

    rerender(
      <ChatList
@@ -23,7 +23,6 @@ describe("generic tool activity semantics", () => {
    ['generate_image({"prompt":"private launch art"})', "Generated image", ""],
    ['spawn({"label":"Research competitors","task":"private task"})', "Delegated task", "Research competitors"],
    ['message({"channel":"telegram","content":"private message"})', "Sent message", "telegram"],
-    ['send_session_message({"to":"@reviewer","content":"private message","expect_reply":true})', "Asked", "@reviewer"],
    ['my({"action":"check","key":"context_window_tokens"})', "Checked agent settings", "context_window_tokens"],
    ['my({"action":"set","key":"model","value":"private-model"})', "Updated agent settings", "model"],
    ['cron({"action":"add","name":"Daily digest","message":"private prompt"})', "Scheduled automation", "Daily digest"],
@@ -41,60 +40,6 @@ describe("generic tool activity semantics", () => {
    expect(`${presentation.label} ${presentation.detail}`).not.toMatch(/[{}]|private|tool-results/);
  });

-  it("renders a handle target once and uses plural copy for grouped messages", () => {
-    const first = parseGenericToolTrace(
-      'send_session_message({"to":"@kai","content":"first","expect_reply":false})',
-    )!;
-    const second = parseGenericToolTrace(
-      'send_session_message({"to":"@mira","content":"second","expect_reply":false})',
-    )!;
-
-    const single = describeGenericToolRun([{ trace: first, status: "done" }]);
-    expect([single.label, single.detail].filter(Boolean).join(" ")).toBe("Sent to @kai");
-
-    const grouped = describeGenericToolRun([
-      { trace: first, status: "done" },
-      { trace: second, status: "done" },
-    ]);
-    expect(grouped).toMatchObject({
-      label: "Sent messages",
-      detail: "",
-      aside: "2 messages",
-    });
-  });
-
-  it.each([
-    [true, "running", "Asking"],
-    [true, "done", "Asked"],
-    [false, "running", "Sending to"],
-    [false, "done", "Sent to"],
-    [false, "error", "Could not reach"],
-  ] as const)(
-    "describes expect_reply=%s handle activity while %s",
-    (expectReply, status, label) => {
-      const presentation = describeRun(
-        `send_session_message({"to":"@kai","content":"private","expect_reply":${expectReply}})`,
-        status,
-      );
-      expect(presentation).toMatchObject({ label, detail: "@kai" });
-    },
-  );
-
-  it.each([
-    ["true", "Asked"],
-    ["1", "Asked"],
-    ["yes", "Asked"],
-    ["false", "Sent to"],
-    ["0", "Sent to"],
-    ["no", "Sent to"],
-  ])("matches backend boolean casting for expect_reply=%s", (expectReply, label) => {
-    const presentation = describeRun(
-      `send_session_message({"to":"@kai","content":"private","expect_reply":"${expectReply}"})`,
-      "done",
-    );
-    expect(presentation).toMatchObject({ label, detail: "@kai" });
-  });
-
  it.each([
    ["running", "Generating image"],
    ["done", "Generated image"],
@@ -28,53 +28,6 @@ describe("MarkdownTextRenderer", () => {
    );
  });

-  it("highlights only known handle handles in prose with their identity color", () => {
-    render(
-      <MarkdownTextRenderer
-        sessionHandles={[{
-          id: "handle-jules",
-          name: "jules",
-          session_key: "websocket:jules",
-          color_slot: 0,
-        }]}
-      >
-        {"已直接回复 @jules；未知 @ghost；邮箱 hello@jules.test；代码 `@jules`。"}
-      </MarkdownTextRenderer>,
-    );
-
-    const mention = screen.getByTestId("message-handle-mention-jules");
-    expect(mention).toHaveTextContent("@jules");
-    expect(mention).toHaveClass("text-foreground");
-    expect(mention.parentElement?.getAttribute("style"))
-      .toContain("var(--session-handle-0)");
-    expect(mention.closest("a")).toHaveAttribute(
-      "href",
-      "#/chat/websocket%3Ajules",
-    );
-    expect(screen.getByText("@jules", { selector: "code" })).toBeInTheDocument();
-    expect(screen.getByText(/未知 @ghost/)).toBeInTheDocument();
-    expect(screen.getByText(/hello@jules\.test/)).toBeInTheDocument();
-    expect(screen.getAllByText("@jules")).toHaveLength(2);
-  });
-
-  it("does not highlight handle handles inside raw or normalized HTML", () => {
-    render(
-      <MarkdownTextRenderer
-        sessionHandles={[{
-          id: "handle-jules",
-          name: "jules",
-          session_key: "websocket:jules",
-          color_slot: 0,
-        }]}
-      >
-        {"<code>@jules</code> <span>@jules</span> <mark>@jules</mark> outside @jules"}
-      </MarkdownTextRenderer>,
-    );
-
-    expect(screen.getAllByTestId("message-handle-mention-jules")).toHaveLength(1);
-    expect(screen.getByTestId("message-handle-mention-jules")).toHaveTextContent("@jules");
-  });
-
  it("does not link non-WebUI session references", () => {
    const { container } = render(
      <MarkdownTextRenderer>
@@ -2,7 +2,6 @@ import { act, fireEvent, render, screen, waitFor } from "@testing-library/react"
 import { describe, expect, it, vi } from "vitest";

 import { MessageBubble } from "@/components/MessageBubble";
-import { preloadMarkdownText } from "@/components/MarkdownText";
 import { fmtDateTime, formatMessageEndTime } from "@/lib/format";
 import type {
  CliAppInfo,
@@ -114,6 +113,28 @@ describe("MessageBubble", () => {
    expect(screen.queryByRole("button", { name: "Fork" })).not.toBeInTheDocument();
  });

+  it("renders cross-session input with its public handle", () => {
+    const message: UIMessage = {
+      id: "session-message:message-1",
+      role: "user",
+      content: "Please review this.",
+      createdAt: 1_700_000_000_123,
+      sessionMessage: {
+        message_id: "message-1",
+        session: {
+          id: "handle_0123456789abcdef0123456789abcdef",
+          name: "mira-0123456789",
+        },
+      },
+    };
+
+    const { container } = render(<MessageBubble message={message} />);
+
+    expect(container.querySelector("[data-session-message]")).toBeInTheDocument();
+    expect(screen.getByText("@mira-0123456789")).toBeInTheDocument();
+    expect(screen.getByText("Please review this.")).toBeInTheDocument();
+  });
+
  it("outlines temporary-chat user messages with a short dashed border", () => {
    const message: UIMessage = {
      id: "u-temporary",
@@ -594,11 +615,11 @@ describe("MessageBubble", () => {
    expect(screen.getByTestId("message-mcp-mention-logo-browserbase")).toBeInTheDocument();
  });

-  it("renders new # session references as links", () => {
+  it("renders persisted session mentions inside sent user messages", () => {
    const message: UIMessage = {
      id: "u-session",
      role: "user",
-      content: "Use #收费设计",
+      content: "Use @收费设计 as context",
      createdAt: Date.now(),
      sessionMentions: [{
        name: "收费设计",
@@ -609,113 +630,13 @@ describe("MessageBubble", () => {

    render(<MessageBubble message={message} />);

-    const token = screen.getByTestId("message-session-reference-收费设计");
-    expect(token).toHaveTextContent("#收费设计");
+    const token = screen.getByTestId("message-session-mention-收费设计");
+    expect(token).toHaveTextContent("@收费设计");
    expect(token).toHaveAttribute("title", "Session: 收费设计");
    expect(token.closest("a")).toHaveAttribute("href", "#/chat/websocket%3Apricing");
-  });
-
-  it("prefers legacy @ session metadata over a same-name catalog capability", () => {
-    const message: UIMessage = {
-      id: "u-legacy-session",
-      role: "user",
-      content: "Review @zoom",
-      createdAt: Date.now(),
-      sessionMentions: [{
-        name: "zoom",
-        session_key: "websocket:zoom-notes",
-        title: "Zoom notes",
-      }],
-    };
-
-    render(<MessageBubble message={message} cliApps={CLI_APPS} />);
-
-    const token = screen.getByTestId("message-session-reference-zoom");
-    expect(token).toHaveTextContent("@zoom");
-    expect(token.closest("a")).toHaveAttribute("href", "#/chat/websocket%3Azoom-notes");
-    expect(screen.queryByTestId("message-cli-mention-zoom")).not.toBeInTheDocument();
-  });
-
-  it("keeps a new # reference distinct from a structured same-name capability", () => {
-    const message: UIMessage = {
-      id: "u-session-and-cli",
-      role: "user",
-      content: "Compare #zoom with @zoom",
-      createdAt: Date.now(),
-      sessionMentions: [{
-        name: "zoom",
-        session_key: "websocket:zoom-notes",
-        title: "Zoom notes",
-      }],
-      cliApps: [{ name: "zoom" }],
-    };
-
-    render(<MessageBubble message={message} cliApps={CLI_APPS} />);
-
-    expect(screen.getByTestId("message-session-reference-zoom")).toHaveTextContent("#zoom");
-    expect(screen.getByTestId("message-cli-mention-zoom")).toHaveTextContent("@zoom");
-  });
-
-  it("renders incoming handle input as assistant markdown with session provenance", async () => {
-    await act(async () => {
-      await preloadMarkdownText();
-    });
-    const message: UIMessage = {
-      id: "handle-input-1",
-      role: "user",
-      content: "**Please verify** the release notes.",
-      createdAt: Date.now(),
-      sessionMessage: {
-        direction: "incoming",
-        message_id: "handle-message-1",
-        session: {
-          id: "handle_reviewer",
-          name: "reviewer",
-          color_slot: 4,
-          session_key: "websocket:reviewer",
-        },
-      },
-    };
-
-    const { container } = render(
-      <MessageBubble message={message} sessionDirectory={[message.sessionMessage!.session]} />,
+    expect(token.closest("a")?.getAttribute("style")).toContain(
+      "text-decoration-color: var(--inline-token-highlight)",
    );
-
-    const sessionMessage = container.querySelector('[data-handle-message="incoming"]');
-    expect(sessionMessage).toHaveClass("w-full");
-    expect(screen.getByText("Please verify").tagName).toBe("STRONG");
-    const sessionLink = screen.getByRole("link", { name: "@reviewer" });
-    expect(sessionLink).toHaveAttribute("href", "#/chat/websocket%3Areviewer");
-    const sessionRange = sessionMessage?.querySelector("[data-handle-message-body]");
-    expect(sessionRange).toHaveClass("border-s-2", "rounded-es-[16px]", "ps-2.5");
-    expect(sessionRange?.getAttribute("style")).toContain("var(--session-handle-4)");
-  });
-
-  it("renders provenance for a deleted handle as plain text", async () => {
-    await act(async () => {
-      await preloadMarkdownText();
-    });
-    const message: UIMessage = {
-      id: "handle-input-deleted",
-      role: "user",
-      content: "This message remains in history.",
-      createdAt: Date.now(),
-      sessionMessage: {
-        direction: "incoming",
-        message_id: "handle-message-deleted",
-        session: {
-          id: "handle_deleted",
-          name: "noah",
-          color_slot: 2,
-          session_key: "websocket:noah",
-        },
-      },
-    };
-
-    render(<MessageBubble message={message} sessionDirectory={[]} />);
-
-    expect(screen.getByText("@noah")).toBeInTheDocument();
-    expect(screen.queryByRole("link", { name: "@noah" })).not.toBeInTheDocument();
  });

  it("copies completed assistant replies from the action row", async () => {
@@ -504,7 +504,7 @@ describe("NanobotClient", () => {
    expect(handler).toHaveBeenCalledTimes(3);
  });

-  it("records canonical run status without an onChat subscriber", () => {
+  it("records goal_status run strip without an onChat subscriber", () => {
    const client = new NanobotClient({
      url: "ws://test",
      reconnect: false,
@@ -527,50 +527,7 @@ describe("NanobotClient", () => {
    expect(client.getRunStartedAt("chat-strip")).toBeNull();
  });

-  it("starts the run projection immediately when a lifecycle message is submitted", () => {
-    vi.useFakeTimers();
-    vi.setSystemTime(new Date("2026-08-13T10:00:00.000Z"));
-    const client = new NanobotClient({
-      url: "ws://test",
-      reconnect: false,
-      socketFactory: (url) => new FakeSocket(url) as unknown as WebSocket,
-    });
-    const handler = vi.fn();
-    client.onRunStatus(handler);
-    client.connect();
-    lastSocket().fakeOpen();
-
-    client.sendMessage("chat-optimistic", "hello", undefined, {
-      turnId: "turn-optimistic",
-    });
-
-    const submittedAt = Date.now() / 1000;
-    expect(client.getRunStartedAt("chat-optimistic")).toBe(submittedAt);
-    expect(handler).toHaveBeenLastCalledWith("chat-optimistic", submittedAt);
-    expect(client.hasUnsettledRun("chat-optimistic")).toBe(true);
-  });
-
-  it("does not start a separate run projection for side-channel guidance", () => {
-    const client = new NanobotClient({
-      url: "ws://test",
-      reconnect: false,
-      socketFactory: (url) => new FakeSocket(url) as unknown as WebSocket,
-    });
-    const handler = vi.fn();
-    client.onRunStatus(handler);
-    client.connect();
-    lastSocket().fakeOpen();
-
-    client.sendMessage("chat-guidance-only", "focus here", undefined, {
-      turnId: "turn-guidance-only",
-      startsNewRun: false,
-    });
-
-    expect(client.getRunStartedAt("chat-guidance-only")).toBeNull();
-    expect(handler).not.toHaveBeenCalled();
-  });
-
-  it("clears the local run status immediately when a stop is requested", () => {
+  it("clears the local run strip immediately when a stop is requested", () => {
    const client = new NanobotClient({
      url: "ws://test",
      reconnect: false,
@@ -595,7 +552,7 @@ describe("NanobotClient", () => {
    expect(handler).toHaveBeenLastCalledWith("chat-stop", null);
  });

-  it("clears stale run status when reconnecting after a dropped socket", async () => {
+  it("clears stale run strip when reconnecting after a dropped socket", async () => {
    const client = new NanobotClient({
      url: "ws://test",
      reconnect: true,
@@ -621,7 +578,7 @@ describe("NanobotClient", () => {
    expect(FakeSocket.instances.length).toBeGreaterThan(1);
  });

-  it("clears run status when a turn_end arrives without idle", () => {
+  it("clears run strip when a turn_end arrives without idle", () => {
    const client = new NanobotClient({
      url: "ws://test",
      reconnect: false,
@@ -771,7 +728,6 @@ describe("NanobotClient", () => {
    expect(
      client.reconcileCanonicalCompletion("chat-rejected", requestGeneration, []),
    ).toBe(true);
-    expect(client.getRunStartedAt("chat-rejected")).toBeNull();
  });

  it("does not let an older rejection settle or stop a newer run", () => {
@@ -2106,7 +2062,7 @@ describe("NanobotClient", () => {
    );
  });

-  it("keeps session references and handle mentions separate on the wire", () => {
+  it("includes session mentions in outbound messages", () => {
    const client = new NanobotClient({
      url: "ws://test",
      reconnect: false,
@@ -2115,35 +2071,23 @@ describe("NanobotClient", () => {
    client.connect();
    lastSocket().fakeOpen();

-    client.sendMessage("chat-current", "Use #pricing and ask @mira", undefined, {
+    client.sendMessage("chat-current", "Use @pricing", undefined, {
      sessionMentions: [{
        name: "pricing",
        session_key: "websocket:pricing",
        title: "Pricing",
      }],
-      sessionHandles: [{
-        id: "handle_mira",
-        name: "mira",
-        session_key: "websocket:mira",
-        color_slot: 3,
-      }],
    });

    expect(lastSocket().sent).toContain(JSON.stringify({
      type: "message",
      chat_id: "chat-current",
-      content: "Use #pricing and ask @mira",
+      content: "Use @pricing",
      session_mentions: [{
        name: "pricing",
        session_key: "websocket:pricing",
        title: "Pricing",
      }],
-      session_handles: [{
-        id: "handle_mira",
-        name: "mira",
-        session_key: "websocket:mira",
-        color_slot: 3,
-      }],
      webui: true,
    }));
  });
@@ -127,14 +127,15 @@ const MCP_PRESETS: McpPresetInfo[] = [
  },
 ];

-function session(
-  chatId: string,
-  title: string,
-  preview = "",
-  mentionName = title,
-): ChatSummary {
+function session(chatId: string, title: string, preview = ""): ChatSummary {
+  const key = `websocket:${chatId}`;
+  const handleId = Array.from(chatId)
+    .map((character) => character.codePointAt(0)?.toString(16).padStart(4, "0") ?? "0000")
+    .join("")
+    .padEnd(32, "0")
+    .slice(0, 32);
  return {
-    key: `websocket:${chatId}`,
+    key,
    channel: "websocket",
    chatId,
    createdAt: null,
@@ -142,10 +143,8 @@ function session(
    title,
    preview,
    handle: {
-      id: `handle_${chatId}`,
-      name: mentionName,
-      color_slot: 2,
-      session_key: `websocket:${chatId}`,
+      id: `handle_${handleId}`,
+      name: title,
    },
  };
 }
@@ -1733,32 +1732,32 @@ describe("ThreadComposer", () => {

    const input = screen.getByLabelText("Message input");
    fireEvent.change(input, {
-      target: { value: "普通文字 #收费设计", selectionStart: 10 },
+      target: { value: "普通文字 @收费设计", selectionStart: 10 },
    });
-    expect(screen.queryByTestId("composer-session-reference-收费设计")).not.toBeInTheDocument();
+    expect(screen.queryByTestId("composer-session-mention-收费设计")).not.toBeInTheDocument();
    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenLastCalledWith("普通文字 #收费设计", undefined, undefined);
+    expect(onSend).toHaveBeenLastCalledWith("普通文字 @收费设计", undefined, undefined);

    fireEvent.change(input, {
-      target: { value: "参考 #收费", selectionStart: 6 },
+      target: { value: "参考 @收费", selectionStart: 6 },
    });

    expect(screen.getByRole("group", { name: "Nanobot conversations" })).toBeInTheDocument();
-    expect(screen.getByRole("option", { name: /^收费设计 #收费设计$/i }))
-      .toBeInTheDocument();
+    expect(screen.getByRole("option", { name: /@收费设计/i })).toBeInTheDocument();
    fireEvent.keyDown(input, { key: "Tab" });

-    expect(input).toHaveValue("参考 #收费设计 ");
-    const mention = screen.getByTestId("composer-session-reference-收费设计");
-    expect(mention).toHaveTextContent("#收费设计");
+    expect(input).toHaveValue("参考 @收费设计 ");
+    const mention = screen.getByTestId("composer-session-mention-收费设计");
+    expect(mention).toHaveTextContent("@收费设计");
    expect(mention).toHaveClass("font-normal");
    expect(mention).not.toHaveClass("font-[550]");
    expect(mention.closest("a")).toBeNull();

    fireEvent.click(screen.getByRole("button", { name: "Send message" }));

-    expect(onSend).toHaveBeenCalledWith("参考 #收费设计", undefined, {
+    expect(onSend).toHaveBeenCalledWith("参考 @收费设计", undefined, {
      sessionMentions: [{
+        id: session("pricing", "收费设计").handle?.id,
        name: "收费设计",
        session_key: "websocket:pricing",
        title: "收费设计",
@@ -1766,198 +1765,6 @@ describe("ThreadComposer", () => {
    });
  });

-  it("keeps a selected session reference bound across title refreshes", () => {
-    const onSend = vi.fn();
-    const target = session("planning", "Plan");
-    const { rerender } = render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[target]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, { target: { value: "#Pla", selectionStart: 4 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-
-    rerender(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[{ ...target, title: "Renamed plan" }]}
-      />,
-    );
-
-    expect(screen.getByTestId("composer-session-reference-Plan"))
-      .toHaveTextContent("#Plan");
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("#Plan", undefined, {
-      sessionMentions: [{
-        name: "Plan",
-        session_key: "websocket:planning",
-        title: "Renamed plan",
-      }],
-    });
-  });
-
-  it("does not revive structured session identity after its token is removed", () => {
-    const onSend = vi.fn();
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[session("pricing", "收费设计", "讨论云存储")]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, {
-      target: { value: "#收费", selectionStart: 3 },
-    });
-    fireEvent.keyDown(input, { key: "Tab" });
-    expect(screen.getByTestId("composer-session-reference-收费设计")).toBeInTheDocument();
-
-    fireEvent.change(input, { target: { value: "", selectionStart: 0 } });
-    fireEvent.change(input, {
-      target: { value: "普通文字 #收费设计", selectionStart: 10 },
-    });
-
-    expect(screen.queryByTestId("composer-session-reference-收费设计")).not.toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("普通文字 #收费设计", undefined, undefined);
-  });
-
-  it("does not migrate a structured identity across an atomic select-all replacement", () => {
-    const onSend = vi.fn();
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[session("pricing", "收费设计", "讨论云存储")]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input") as HTMLTextAreaElement;
-    fireEvent.change(input, { target: { value: "#收费", selectionStart: 3 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-    expect(screen.getByTestId("composer-session-reference-收费设计")).toBeInTheDocument();
-
-    input.setSelectionRange(0, input.value.length);
-    fireEvent.select(input);
-    const replacement = "普通文字 #收费设计";
-    fireEvent.change(input, {
-      target: {
-        value: replacement,
-        selectionStart: replacement.length,
-        selectionEnd: replacement.length,
-      },
-    });
-
-    expect(screen.queryByTestId("composer-session-reference-收费设计")).not.toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith(replacement, undefined, undefined);
-  });
-
-  it("keeps same-name session references distinct from capability mentions", () => {
-    const onSend = vi.fn();
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-        sessions={[session("blender-chat", "blender")]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, { target: { value: "#blend", selectionStart: 6 } });
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(screen.getByTestId("composer-session-reference-blender")).toBeInTheDocument();
-
-    const next = "#blender @blend";
-    fireEvent.change(input, { target: { value: next, selectionStart: next.length } });
-    fireEvent.keyDown(input, { key: "Enter" });
-
-    expect(screen.getByTestId("composer-session-reference-blender")).toBeInTheDocument();
-    expect(screen.getByTestId("composer-cli-mention-blender")).toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("#blender @blender", undefined, {
-      cliApps: [expect.objectContaining({ name: "blender" })],
-      sessionMentions: [{
-        name: "blender",
-        session_key: "websocket:blender-chat",
-        title: "blender",
-      }],
-    });
-  });
-
-  it("drops structured session semantics when the identity leaves the current catalog", () => {
-    const onSend = vi.fn();
-    const target = session("pricing", "pricing", "", "pricing");
-    const { rerender } = render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[target]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, { target: { value: "#pricing", selectionStart: 8 } });
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(screen.getByTestId("composer-session-reference-pricing")).toBeInTheDocument();
-
-    rerender(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[]}
-      />,
-    );
-    expect(screen.queryByTestId("composer-session-reference-pricing")).not.toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("#pricing", undefined, undefined);
-  });
-
-  it("exposes mention suggestions as an aria-activedescendant combobox and ignores IME Enter", () => {
-    render(
-      <ThreadComposer
-        onSend={vi.fn()}
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
-    const combobox = screen.getByRole("combobox", { name: "Message input" });
-    const listbox = screen.getByRole("listbox", { name: "Mentions" });
-    const firstOption = screen.getByRole("option", { name: /@gimp/i });
-    expect(combobox).toHaveAttribute("aria-expanded", "true");
-    expect(combobox).toHaveAttribute("aria-controls", listbox.id);
-    expect(combobox).toHaveAttribute("aria-activedescendant", firstOption.id);
-    expect(firstOption).toHaveAttribute("tabindex", "-1");
-
-    fireEvent.keyDown(input, { key: "Enter", isComposing: true });
-    expect(input).toHaveValue("@");
-    expect(listbox).toBeInTheDocument();
-
-    fireEvent.keyDown(input, { key: "ArrowDown" });
-    const secondOption = screen.getByRole("option", { name: /@blender/i });
-    expect(combobox).toHaveAttribute("aria-activedescendant", secondOption.id);
-  });
-
-  it("keeps combobox semantics when the mention popup is closed", () => {
-    render(<ThreadComposer onSend={vi.fn()} placeholder="Type your message..." />);
-
-    const input = screen.getByRole("combobox", { name: "Message input" });
-    expect(input).toHaveAttribute("aria-autocomplete", "list");
-    expect(input).toHaveAttribute("aria-expanded", "false");
-    expect(input).not.toHaveAttribute("aria-controls");
-    expect(input).not.toHaveAttribute("aria-activedescendant");
-  });
-
  it("turns a dropped sidebar session into the shared structured mention", () => {
    const onSend = vi.fn();
    render(
@@ -1986,7 +1793,7 @@ describe("ThreadComposer", () => {

    expect(input).toHaveValue("Compare notes");
    expect(screen.getByTestId("composer-session-drag-preview"))
-      .toHaveTextContent("#收费设计");
+      .toHaveTextContent("@收费设计");

    fireEvent.dragEnd(document);
    expect(screen.queryByTestId("composer-session-drag-preview")).not.toBeInTheDocument();
@@ -1996,14 +1803,15 @@ describe("ThreadComposer", () => {

    fireEvent.drop(input, { dataTransfer });

-    expect(input).toHaveValue("Compare #收费设计 notes");
+    expect(input).toHaveValue("Compare @收费设计 notes");
    expect(screen.queryByTestId("composer-session-drag-preview")).not.toBeInTheDocument();
-    expect(screen.getByTestId("composer-session-reference-收费设计"))
-      .toHaveTextContent("#收费设计");
+    expect(screen.getByTestId("composer-session-mention-收费设计"))
+      .toHaveTextContent("@收费设计");

    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("Compare #收费设计 notes", undefined, {
+    expect(onSend).toHaveBeenCalledWith("Compare @收费设计 notes", undefined, {
      sessionMentions: [{
+        id: session("pricing", "收费设计").handle?.id,
        name: "收费设计",
        session_key: "websocket:pricing",
        title: "收费设计",
@@ -2033,154 +1841,6 @@ describe("ThreadComposer", () => {
    expect(screen.queryByTestId("composer-session-drag-preview")).not.toBeInTheDocument();
  });

-  it("uses stable handle identities without exposing session titles", () => {
-    const handles = [
-      session("a", "First planning title", "", "Plan"),
-      session("b", "Second planning title", "", "Plan-2"),
-      session("blender-chat", "3D notes", "", "Blender"),
-    ];
-    render(
-      <ThreadComposer
-        onSend={vi.fn()}
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-        mcpPresets={MCP_PRESETS}
-        handleSessions={handles}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input");
-    fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
-
-    const palette = screen.getByRole("listbox", { name: "Mentions" });
-    expect(within(palette).getAllByRole("group").map((group) => (
-      group.getAttribute("aria-label")
-    ))).toEqual(["Nanobot conversations", "CLI apps", "MCP services"]);
-    const firstSession = screen.getByRole("option", { name: /^@Plan$/i });
-    expect(firstSession).toHaveAttribute("aria-selected", "true");
-    expect(input).toHaveAttribute("aria-activedescendant", firstSession.id);
-    expect(screen.getByRole("option", { name: /^@Plan-2$/i }))
-      .toBeInTheDocument();
-    expect(screen.getByRole("group", { name: "Nanobot conversations" }))
-      .toBeInTheDocument();
-    expect(screen.getByRole("group", { name: "CLI apps" })).toBeInTheDocument();
-    expect(screen.getByRole("option", { name: /^@Blender$/i }))
-      .toBeInTheDocument();
-    expect(screen.getByRole("option", { name: /Blender @blender Use/i }))
-      .toBeInTheDocument();
-    expect(screen.queryByText("First planning title")).not.toBeInTheDocument();
-    expect(screen.queryByText("Second planning title")).not.toBeInTheDocument();
-  });
-
-  it("binds every same-name occurrence to one selected namespace across queue replay", () => {
-    const onSend = vi.fn();
-    const sameNameSession = session("blender-handle", "Session title", "", "blender");
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        onStop={vi.fn()}
-        isStreaming
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-        handleSessions={[sameNameSession]}
-      />,
-    );
-
-    const input = screen.getByRole("combobox", { name: "Message input" });
-    fireEvent.change(input, { target: { value: "@blend", selectionStart: 6 } });
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(screen.getByTestId("composer-handle-mention-blender")).toBeInTheDocument();
-
-    const withSecondOccurrence = "@blender then @blender";
-    fireEvent.change(input, {
-      target: { value: withSecondOccurrence, selectionStart: withSecondOccurrence.length },
-    });
-    expect(screen.getAllByTestId("composer-handle-mention-blender")).toHaveLength(2);
-
-    input.setSelectionRange("@blender then ".length, withSecondOccurrence.length);
-    fireEvent.select(input);
-    fireEvent.change(input, {
-      target: { value: "@blender then @blend", selectionStart: 20 },
-    });
-    const cliOption = screen.getByRole("option", { name: /Blender @blender .* CLI/i });
-    fireEvent.mouseDown(cliOption);
-
-    expect(screen.getAllByTestId("composer-cli-mention-blender")).toHaveLength(2);
-    expect(screen.queryByTestId("composer-handle-mention-blender")).not.toBeInTheDocument();
-    fireEvent.keyDown(input, { key: "Enter" });
-    fireEvent.keyDown(input, { key: "Enter" });
-
-    expect(onSend).toHaveBeenCalledWith("@blender then @blender", undefined, {
-      cliApps: [expect.objectContaining({ name: "blender" })],
-      continueActiveTurn: true,
-    });
-  });
-
-  it("does not reinterpret a disappeared handle as a same-name CLI app", () => {
-    const onSend = vi.fn();
-    const handle = session("blender-handle", "Session title", "", "blender");
-    const { rerender } = render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-        handleSessions={[handle]}
-      />,
-    );
-
-    const input = screen.getByRole("combobox", { name: "Message input" });
-    fireEvent.change(input, { target: { value: "@blend", selectionStart: 6 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-    expect(screen.getByTestId("composer-handle-mention-blender")).toBeInTheDocument();
-
-    rerender(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        cliApps={CLI_APPS}
-        handleSessions={[]}
-      />,
-    );
-
-    expect(screen.queryByTestId("composer-handle-mention-blender")).not.toBeInTheDocument();
-    expect(screen.queryByTestId("composer-cli-mention-blender")).not.toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith("@blender", undefined, undefined);
-  });
-
-  it("supports a prototype-named MCP through live and queued mention parsing", () => {
-    const onSend = vi.fn();
-    const constructorPreset: McpPresetInfo = {
-      ...MCP_PRESETS[0],
-      name: "constructor",
-      display_name: "Constructor",
-    };
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        onStop={vi.fn()}
-        isStreaming
-        placeholder="Type your message..."
-        mcpPresets={[constructorPreset]}
-      />,
-    );
-
-    const input = screen.getByRole("combobox", { name: "Message input" });
-    fireEvent.change(input, {
-      target: { value: "use @constructor", selectionStart: 16 },
-    });
-    expect(screen.getByTestId("composer-mcp-mention-constructor")).toBeInTheDocument();
-
-    fireEvent.keyDown(input, { key: "Enter" });
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(screen.getByText("use @constructor")).toBeInTheDocument();
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(onSend).toHaveBeenCalledWith("use @constructor", undefined, {
-      mcpPresets: [expect.objectContaining({ name: "constructor" })],
-      continueActiveTurn: true,
-    });
-  });
-
  it("releases the eight-session limit when a mention is removed", () => {
    const onSend = vi.fn();
    render(
@@ -2196,21 +1856,11 @@ describe("ThreadComposer", () => {

    const input = screen.getByLabelText("Message input") as HTMLTextAreaElement;
    for (let index = 0; index < 8; index += 1) {
-      const value = `${input.value}${input.value ? " " : ""}#Topic${index}`;
-      input.setSelectionRange(input.value.length, input.value.length);
-      fireEvent.select(input);
+      const value = `${input.value}${input.value ? " " : ""}@Topic${index}`;
      fireEvent.change(input, { target: { value, selectionStart: value.length } });
      fireEvent.keyDown(input, { key: "Tab" });
    }
-    const withoutFirst = input.value.replace("#Topic0 ", "");
-    input.setSelectionRange(0, "#Topic0 ".length);
-    fireEvent.select(input);
-    fireEvent.change(input, {
-      target: { value: withoutFirst, selectionStart: 0 },
-    });
-    const replacement = `${withoutFirst}#Topic8`;
-    input.setSelectionRange(withoutFirst.length, withoutFirst.length);
-    fireEvent.select(input);
+    const replacement = `${input.value.replace("@Topic0 ", "")} @Topic8`;
    fireEvent.change(input, {
      target: { value: replacement, selectionStart: replacement.length },
    });
@@ -2224,7 +1874,7 @@ describe("ThreadComposer", () => {
    ))).toEqual(expect.arrayContaining(["websocket:topic-8"]));
  });

-  it("keeps a selected handle mention when queuing guidance for the active turn", () => {
+  it("keeps a selected session stable across refreshes and queued guidance", () => {
    const onSend = vi.fn();
    const target = session("z-target", "Plan", "Original plan");
    const { rerender } = render(
@@ -2233,7 +1883,7 @@ describe("ThreadComposer", () => {
        onStop={vi.fn()}
        isStreaming
        placeholder="Type your message..."
-        handleSessions={[target]}
+        sessions={[target]}
      />,
    );

@@ -2247,26 +1897,23 @@ describe("ThreadComposer", () => {
        onStop={vi.fn()}
        isStreaming
        placeholder="Type your message..."
-        handleSessions={[
+        sessions={[
          { ...target, title: "Renamed plan" },
-          session("a-new", "Another title", target.preview, "Other"),
+          session("a-new", "Plan", target.preview),
        ]}
      />,
    );

-    expect(screen.getByTestId("composer-handle-mention-Plan")).toHaveTextContent("@Plan");
-    fireEvent.keyDown(input, { key: "Enter" });
-    expect(
-      within(screen.getByRole("group", { name: "Queued guidance" })).getByText("@Plan"),
-    ).toBeInTheDocument();
+    expect(screen.getByTestId("composer-session-mention-Plan")).toHaveTextContent("@Plan");
    fireEvent.keyDown(input, { key: "Enter" });
+    fireEvent.click(screen.getByRole("button", { name: "Guide" }));

    expect(onSend).toHaveBeenCalledWith("@Plan", undefined, {
-      sessionHandles: [{
-        id: "handle_z-target",
+      sessionMentions: [{
+        id: session("z-target", "Plan").handle?.id,
        name: "Plan",
        session_key: "websocket:z-target",
-        color_slot: 2,
+        title: "Plan",
      }],
      continueActiveTurn: true,
    });
@@ -2325,49 +1972,6 @@ describe("ThreadComposer", () => {
    expect(input).toHaveValue(`please use $${skillName} `);
  });

-  it("keeps a later session occurrence bound while completing an earlier skill", () => {
-    const onSend = vi.fn();
-    const skillName = "arxiv-intelligence-filter";
-    render(
-      <ThreadComposer
-        onSend={onSend}
-        placeholder="Type your message..."
-        sessions={[session("plan", "Plan")]}
-        skills={[{
-          name: skillName,
-          description: "Research papers",
-          source: "builtin",
-          enabled: true,
-          available: true,
-        }]}
-      />,
-    );
-
-    const input = screen.getByLabelText("Message input") as HTMLTextAreaElement;
-    fireEvent.change(input, { target: { value: "#Pla", selectionStart: 4 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-    expect(screen.getByTestId("composer-session-reference-Plan")).toBeInTheDocument();
-
-    input.setSelectionRange(0, 0);
-    fireEvent.select(input);
-    const withSkillQuery = `$arx ${input.value}`;
-    fireEvent.change(input, {
-      target: { value: withSkillQuery, selectionStart: 4, selectionEnd: 4 },
-    });
-    fireEvent.keyDown(input, { key: "Tab" });
-
-    expect(input).toHaveValue(`$${skillName} #Plan `);
-    expect(screen.getByTestId("composer-session-reference-Plan")).toBeInTheDocument();
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-    expect(onSend).toHaveBeenCalledWith(`$${skillName} #Plan`, undefined, {
-      sessionMentions: [{
-        name: "Plan",
-        session_key: "websocket:plan",
-        title: "Plan",
-      }],
-    });
-  });
-
  it("ranks skill name matches ahead of earlier description matches", () => {
    render(
      <ThreadComposer
@@ -3418,38 +3022,6 @@ describe("ThreadComposer", () => {
    });
  });

-  it("migrates queued guidance from the v1 storage key without losing the prompt", async () => {
-    const legacyKey = "nanobot.webui.composerQueuedGuidance.v1:chat-a";
-    const currentKey = "nanobot.webui.composerQueuedGuidance.v2:chat-a";
-    window.localStorage.setItem(legacyKey, JSON.stringify([{
-      id: "legacy-guidance",
-      text: "keep this older queued prompt",
-      sessionMentions: [{
-        name: "old-handle",
-        session_key: "websocket:old-handle",
-        title: "Old handle",
-      }],
-    }]));
-
-    render(
-      <ThreadComposer
-        onSend={vi.fn()}
-        onStop={vi.fn()}
-        isStreaming
-        pendingQueueKey="chat-a"
-        placeholder="Type your message..."
-      />,
-    );
-
-    expect(await screen.findByText("keep this older queued prompt")).toBeInTheDocument();
-    expect(window.localStorage.getItem(legacyKey)).toBeNull();
-    expect(JSON.parse(window.localStorage.getItem(currentKey) ?? "[]"))
-      .toEqual([expect.objectContaining({
-        id: "legacy-guidance",
-        text: "keep this older queued prompt",
-      })]);
-  });
-
  it("keeps temporary chat guidance in memory only", async () => {
    const onSend = vi.fn();
    const view = render(
@@ -3469,7 +3041,7 @@ describe("ThreadComposer", () => {
    expect(await screen.findByText("do not persist this")).toBeInTheDocument();
    expect(
      window.localStorage.getItem(
-        "nanobot.webui.composerQueuedGuidance.v2:temporary-private",
+        "nanobot.webui.composerQueuedGuidance.v1:temporary-private",
      ),
    ).toBeNull();

@@ -3489,7 +3061,7 @@ describe("ThreadComposer", () => {
    });
    expect(
      window.localStorage.getItem(
-        "nanobot.webui.composerQueuedGuidance.v2:temporary-private",
+        "nanobot.webui.composerQueuedGuidance.v1:temporary-private",
      ),
    ).toBeNull();
  });
@@ -21,7 +21,6 @@ function makeClient() {
    (modelName: string | null, modelPreset?: string | null) => void
  >();
  const sessionUpdateHandlers = new Set<(chatId: string, scope?: string) => void>();
-  const runStatusHandlers = new Set<(chatId: string, startedAt: number | null) => void>();
  const runStartedAtByChatId = new Map<string, number>();
  const runGenerationByChatId = new Map<string, number>();
  const latestRunTurnIdByChatId = new Map<string, string>();
@@ -109,13 +108,6 @@ function makeClient() {
    },
    getRunStartedAt: (chatId: string) => runStartedAtByChatId.get(chatId) ?? null,
    getRunTurnId: (chatId: string) => latestRunTurnIdByChatId.get(chatId) ?? null,
-    onRunStatus: (handler: (chatId: string, startedAt: number | null) => void) => {
-      runStatusHandlers.add(handler);
-      for (const [chatId, startedAt] of runStartedAtByChatId) handler(chatId, startedAt);
-      return () => {
-        runStatusHandlers.delete(handler);
-      };
-    },
    finishRunLocally: vi.fn((chatId: string) => {
      runStartedAtByChatId.delete(chatId);
      latestRunTurnIdByChatId.delete(chatId);
@@ -425,164 +417,6 @@ describe("ThreadShell", () => {
    );
  });

-  it("keeps the current handle handle visible in the thread header", async () => {
-    const client = makeClient();
-    const currentSession = {
-      ...session("handle-handle"),
-      handle: {
-        id: "handle-current",
-        name: "mira",
-        session_key: "websocket:handle-handle",
-        color_slot: 3,
-      },
-    };
-
-    render(wrap(
-      client,
-      <ThreadShell
-        session={currentSession}
-        title="A title that may change independently"
-        onToggleSidebar={() => {}}
-      />,
-    ));
-
-    const handle = await screen.findByTestId("thread-handle-handle");
-    expect(handle).toHaveTextContent("@mira");
-    expect(handle.querySelector("[aria-hidden]")).toBeNull();
-    const headerDecoration = handle.querySelector("span[style*='border-bottom-color']");
-    expect(headerDecoration?.getAttribute("style"))
-      .toContain("var(--session-handle-3)");
-    expect(headerDecoration?.querySelector(".text-foreground"))
-      .toHaveClass("text-foreground");
-  });
-
-  it("pins each handle identity inside its workbench pane", async () => {
-    const client = makeClient();
-    const currentSession = {
-      ...session("pane-handle"),
-      handle: {
-        id: "handle-pane",
-        name: "kai",
-        session_key: "websocket:pane-handle",
-        color_slot: 2,
-      },
-    };
-
-    render(wrap(
-      client,
-      <ThreadShell
-        session={currentSession}
-        title="Investigate incoming messages"
-        onToggleSidebar={() => {}}
-        hideHeaderTitle
-        headerActive={false}
-      />,
-    ));
-
-    expect(screen.queryByTestId("thread-handle-handle")).not.toBeInTheDocument();
-    const identity = await screen.findByTestId("pane-handle-identity");
-    expect(identity).toHaveAttribute("data-active", "false");
-    expect(identity).toHaveAttribute("aria-label", "Session @kai");
-    expect(identity.querySelector("[data-pane-handle-handle]")).toHaveTextContent("@kai");
-    expect(identity.querySelector("[aria-hidden]")).toBeNull();
-    const paneDecoration = identity.querySelector(
-      "[data-pane-handle-handle] span[style*='border-bottom-color']",
-    );
-    expect(paneDecoration?.getAttribute("style")).toContain("var(--session-handle-2)");
-    const paneText = paneDecoration?.querySelector(".text-foreground");
-    expect(paneText).toHaveClass("text-foreground");
-    expect(paneText).not.toHaveClass("opacity-80");
-    expect(identity).not.toHaveTextContent("Investigate incoming messages");
-    expect(identity.className).not.toContain("bg-");
-    expect(identity.className).not.toContain("border-");
-  });
-
-  it("sends a structured handle mention through the focused thread", async () => {
-    const client = makeClient();
-    const source = {
-      ...session("source"),
-      handle: {
-        id: "handle_00000000000000000000000000000001",
-        name: "source",
-        session_key: "websocket:source",
-        color_slot: 1,
-      },
-    };
-    const reviewer = {
-      ...session("reviewer"),
-      handle: {
-        id: "handle_00000000000000000000000000000002",
-        name: "reviewer",
-        session_key: "websocket:reviewer",
-        color_slot: 2,
-      },
-    };
-    render(wrap(
-      client,
-      <ThreadShell
-        session={source}
-        sessions={[source, reviewer]}
-        title="Source"
-        onToggleSidebar={() => {}}
-      />,
-    ));
-
-    const input = await screen.findByLabelText("Message input") as HTMLTextAreaElement;
-    fireEvent.change(input, { target: { value: "@rev", selectionStart: 4 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-    const message = `${input.value}check this`;
-    fireEvent.change(input, { target: { value: message, selectionStart: message.length } });
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-
-    expect(client.sendMessage).toHaveBeenCalledWith(
-      source.chatId,
-      message,
-      undefined,
-      expect.objectContaining({
-        sessionHandles: [reviewer.handle],
-        turnId: expect.any(String),
-      }),
-    );
-  });
-
-  it("offers the focused session's own handle handle as a structured mention", async () => {
-    const client = makeClient();
-    const source = {
-      ...session("source-self"),
-      handle: {
-        id: "handle_00000000000000000000000000000003",
-        name: "bea",
-        session_key: "websocket:source-self",
-        color_slot: 3,
-      },
-    };
-
-    render(wrap(
-      client,
-      <ThreadShell
-        session={source}
-        sessions={[source]}
-        title="Source"
-        onToggleSidebar={() => {}}
-      />,
-    ));
-
-    const input = await screen.findByLabelText("Message input") as HTMLTextAreaElement;
-    fireEvent.change(input, { target: { value: "@be", selectionStart: 3 } });
-    fireEvent.keyDown(input, { key: "Tab" });
-    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
-
-    expect(client.sendMessage).toHaveBeenCalledWith(
-      source.chatId,
-      "@bea",
-      undefined,
-      expect.objectContaining({
-        sessionHandles: [source.handle],
-        turnId: expect.any(String),
-      }),
-    );
-  });
-
  it("keeps inferred file paths non-interactive when the availability probe fails", async () => {
    await preloadMarkdownText();
    const client = makeClient();
@@ -953,7 +787,7 @@ describe("ThreadShell", () => {
    fireEvent.click(badge);
    expect(onOpenModelSettings).toHaveBeenCalledTimes(1);

-    fireEvent.change(screen.getByRole("combobox", { name: "Message input" }), {
+    fireEvent.change(screen.getByRole("textbox", { name: "Message input" }), {
      target: { value: "hello" },
    });
    fireEvent.click(screen.getByRole("button", { name: "Configure model" }));
@@ -1109,39 +943,6 @@ describe("ThreadShell", () => {
    });
  });

-  it("does not offer persisted sessions inside a temporary chat", async () => {
-    const client = makeClient();
-    const handle = {
-      ...session("handle"),
-      title: "Reviewer",
-      handle: {
-        id: "handle_11111111111111111111111111111111",
-        name: "reviewer",
-        color_slot: 3,
-        session_key: "websocket:handle",
-      },
-    };
-    render(wrap(
-      client,
-      <ThreadShell
-        session={session("temporary")}
-        sessions={[handle]}
-        title="Temporary chat"
-        temporary
-        temporaryChatIds={["temporary"]}
-        onToggleSidebar={() => {}}
-      />,
-    ));
-
-    const input = await screen.findByLabelText("Message input");
-    await act(async () => {
-      fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
-    });
-
-    expect(screen.queryByRole("group", { name: "Nanobot conversations" }))
-      .not.toBeInTheDocument();
-  });
-
  it("highlights sent skill references without skill metadata", async () => {
    const client = makeClient();
    render(wrap(
@@ -2251,7 +2052,7 @@ describe("ThreadShell", () => {
    );

    await waitFor(() => expect(historyCalls).toBe(1));
-    const input = screen.getByRole("combobox", { name: "Message input" });
+    const input = screen.getByRole("textbox", { name: "Message input" });
    fireEvent.change(input, { target: { value: "rejected local turn" } });
    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
    await waitFor(() => expect(screen.getByText("rejected local turn")).toBeInTheDocument());
@@ -2488,7 +2289,7 @@ describe("ThreadShell", () => {
    act(() => client._emitSessionUpdate("chat-version-a"));
    await waitFor(() => expect(chatACalls).toBe(2));

-    fireEvent.change(screen.getByRole("combobox", { name: "Message input" }), {
+    fireEvent.change(screen.getByRole("textbox", { name: "Message input" }), {
      target: { value: "new question" },
    });
    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
@@ -2589,7 +2390,7 @@ describe("ThreadShell", () => {
        turn_id: newTurnId,
      });
    });
-    const input = screen.getByRole("combobox", { name: "Message input" });
+    const input = screen.getByRole("textbox", { name: "Message input" });
    fireEvent.change(input, { target: { value: "queued for the new run" } });
    fireEvent.keyDown(input, { key: "Enter" });
    expect(client.sendMessage).not.toHaveBeenCalled();
@@ -2888,7 +2689,7 @@ describe("ThreadShell", () => {
        turn_id: turnId,
      });
    });
-    const input = screen.getByRole("combobox", { name: "Message input" });
+    const input = screen.getByRole("textbox", { name: "Message input" });
    fireEvent.change(input, { target: { value: "queued guidance" } });
    fireEvent.keyDown(input, { key: "Enter" });
    expect(client.sendMessage).not.toHaveBeenCalled();
@@ -2991,7 +2792,7 @@ describe("ThreadShell", () => {
      });
    });
    await waitFor(() => expect(screen.getByText("partial answer")).toBeInTheDocument());
-    const input = screen.getByRole("combobox", { name: "Message input" });
+    const input = screen.getByRole("textbox", { name: "Message input" });
    fireEvent.change(input, { target: { value: "queued guidance" } });
    fireEvent.keyDown(input, { key: "Enter" });
    expect(screen.getByText("queued guidance")).toBeInTheDocument();
@@ -3087,7 +2888,7 @@ describe("ThreadShell", () => {
    });

    await waitFor(() => expect(screen.getByText("Continuing the search.")).toBeInTheDocument());
-    const input = screen.getByRole("combobox", { name: "Message input" });
+    const input = screen.getByRole("textbox", { name: "Message input" });
    fireEvent.change(input, { target: { value: "How is it going?" } });
    fireEvent.keyDown(input, { key: "Enter" });
    fireEvent.keyDown(input, { key: "Enter" });
@@ -4129,56 +3930,50 @@ describe("ThreadShell", () => {
    );
  });

-  it.each(["restricted", "full"] as const)(
-    "offers routable sessions across projects in %s mode",
-    async (accessMode) => {
-      const client = makeClient();
-      const currentScope = {
-        project_path: "/projects/current",
-        access_mode: accessMode,
-      };
-      const sameProject = {
-        ...session("same-project"),
-        title: "Same project",
-        workspaceScope: currentScope,
-        handle: {
-          id: "handle_same_project",
-          name: "same-project",
-          color_slot: 1,
-          session_key: "websocket:same-project",
-        },
-      };
-      const otherProject = {
-        ...session("other-project"),
-        title: "Other project",
-        workspaceScope: {
-          project_path: "/projects/other",
-          access_mode: accessMode,
-        },
-        handle: {
-          id: "handle_other_project",
-          name: "other-project",
-          color_slot: 2,
-          session_key: "websocket:other-project",
-        },
-      };
+  it("offers sessions across projects in restricted mode", async () => {
+    const client = makeClient();
+    const currentScope = {
+      project_path: "/projects/current",
+      access_mode: "restricted" as const,
+    };
+    const sameProject = {
+      ...session("same-project"),
+      title: "Same project",
+      workspaceScope: currentScope,
+      handle: {
+        id: "handle_11111111111111111111111111111111",
+        name: "same-1111111111",
+      },
+    };
+    const otherProject = {
+      ...session("other-project"),
+      title: "Other project",
+      workspaceScope: {
+        project_path: "/projects/other",
+        access_mode: "restricted" as const,
+      },
+      handle: {
+        id: "handle_22222222222222222222222222222222",
+        name: "other-2222222222",
+      },
+    };

-      render(wrap(
-        client,
-        <ThreadShell
-          session={session("current")}
-          sessions={[sameProject, otherProject]}
-          title="Current"
-          onToggleSidebar={() => {}}
-          workspaceScope={currentScope}
-        />,
-      ));
+    render(wrap(
+      client,
+      <ThreadShell
+        session={session("current")}
+        sessions={[sameProject, otherProject]}
+        title="Current"
+        onToggleSidebar={() => {}}
+        workspaceScope={currentScope}
+      />,
+    ));

-      const input = await screen.findByLabelText("Message input");
-      fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
+    const input = await screen.findByLabelText("Message input");
+    fireEvent.change(input, { target: { value: "@", selectionStart: 1 } });
+
+    expect(screen.getByRole("option", { name: /Same project/i })).toBeInTheDocument();
+    expect(screen.getByRole("option", { name: /Other project/i })).toBeInTheDocument();
+  });

-      expect(screen.getByRole("option", { name: /^@same-project$/i })).toBeInTheDocument();
-      expect(screen.getByRole("option", { name: /^@other-project$/i })).toBeInTheDocument();
-    },
-  );
 });
@@ -215,7 +215,7 @@ function ViewportWithPromptNavigator({ messages }: { messages: UIMessage[] }) {
 }

 describe("ThreadViewport", () => {
-  it("keeps unmanaged reasoning disclosure anchored for pointer and keyboard toggles", () => {
+  it("keeps reasoning disclosure anchored for pointer and keyboard toggles", () => {
    const takeUserControl = vi.spyOn(
      ThreadMotionCoordinator.prototype,
      "takeUserControl",
@@ -38,8 +38,6 @@ const SEMANTIC_MESSAGE_FIELDS = [
  "cliApps",
  "mcpPresets",
  "sessionMentions",
-  "sessionHandles",
-  "handle",
  "reasoning",
  "latencyMs",
  "source",
@@ -72,7 +70,6 @@ function fakeClient() {
  const handlers = new Map<string, Set<(ev: InboundEvent) => void>>();
  const statusHandlers = new Set<(status: ConnectionStatus) => void>();
  const errorHandlers = new Set<(error: StreamError) => void>();
-  const runStatusHandlers = new Set<(chatId: string, startedAt: number | null) => void>();
  const runStartedAtByChatId = new Map<string, number>();
  const unsettledRunByChatId = new Map<string, boolean>();
  const goalStateByChatId = new Map<string, GoalStateWsPayload>();
@@ -116,13 +113,6 @@ function fakeClient() {
        errorHandlers.add(handler);
        return () => errorHandlers.delete(handler);
      },
-      onRunStatus(handler: (chatId: string, startedAt: number | null) => void) {
-        runStatusHandlers.add(handler);
-        for (const [chatId, startedAt] of runStartedAtByChatId) {
-          handler(chatId, startedAt);
-        }
-        return () => runStatusHandlers.delete(handler);
-      },
      getRunStartedAt(chatId: string) {
        const v = runStartedAtByChatId.get(chatId);
        return v === undefined ? null : v;
@@ -164,11 +154,6 @@ function fakeClient() {
    emitError(error: StreamError) {
      errorHandlers.forEach((handler) => handler(error));
    },
-    emitRunStatus(chatId: string, startedAt: number | null) {
-      if (startedAt === null) runStartedAtByChatId.delete(chatId);
-      else runStartedAtByChatId.set(chatId, startedAt);
-      runStatusHandlers.forEach((handler) => handler(chatId, startedAt));
-    },
    setUnsettled(chatId: string, unsettled: boolean) {
      unsettledRunByChatId.set(chatId, unsettled);
    },
@@ -197,101 +182,6 @@ async function flushStreamFrame() {
 }

 describe("useNanobotStream", () => {
-  it("keeps a handle mention on the focused chat's optimistic and outbound turn", () => {
-    const fake = fakeClient();
-    const { result } = renderHook(
-      () => useNanobotStream("chat-source", EMPTY_MESSAGES),
-      { wrapper: wrap(fake.client) },
-    );
-    const reviewer = {
-      id: "handle_00000000000000000000000000000001",
-      name: "reviewer",
-      session_key: "websocket:chat-reviewer",
-      color_slot: 3,
-    };
-
-    act(() => {
-      result.current.send("@reviewer check this", undefined, {
-        sessionHandles: [reviewer],
-      });
-    });
-
-    expect(result.current.messages).toEqual([
-      expect.objectContaining({
-        role: "user",
-        content: "@reviewer check this",
-        deliveryStatus: "sending",
-        sessionHandles: [reviewer],
-      }),
-    ]);
-    expect(result.current.isStreaming).toBe(true);
-    expect(fake.client.sendMessage).toHaveBeenCalledWith(
-      "chat-source",
-      "@reviewer check this",
-      undefined,
-      expect.objectContaining({
-        sessionHandles: [reviewer],
-        turnId: expect.any(String),
-      }),
-    );
-  });
-
-  it("renders an incoming handle message before the target model responds", async () => {
-    const fake = fakeClient();
-    const { result } = renderHook(
-      () => useNanobotStream("chat-handle", EMPTY_MESSAGES),
-      { wrapper: wrap(fake.client) },
-    );
-    const sessionMessageEvent: InboundEvent = {
-      event: "session_message",
-      chat_id: "chat-handle",
-      text: "What did you change?",
-      created_at_ms: 1_234,
-      turn_id: "handle-turn-1",
-      turn_phase: "user",
-      session_message: {
-        direction: "incoming",
-        message_id: "handle-message-1",
-        session: {
-          id: "handle_11111111111111111111111111111111",
-          name: "kai",
-          session_key: "websocket:source",
-          color_slot: 2,
-        },
-      },
-    };
-
-    act(() => {
-      fake.emit("chat-handle", sessionMessageEvent);
-      fake.emit("chat-handle", sessionMessageEvent);
-    });
-
-    expect(result.current.messages).toHaveLength(1);
-    expect(result.current.messages[0]).toMatchObject({
-      id: "session-message:handle-message-1",
-      role: "user",
-      content: "What did you change?",
-      createdAt: 1_234,
-      turnId: "handle-turn-1",
-      turnPhase: "user",
-      sessionMessage: sessionMessageEvent.session_message,
-    });
-    expect(result.current.isStreaming).toBe(true);
-
-    act(() => fake.emit("chat-handle", {
-      event: "delta",
-      chat_id: "chat-handle",
-      text: "I changed",
-      turn_id: "handle-turn-1",
-    }));
-    await flushStreamFrame();
-
-    expect(result.current.messages.map((message) => message.role)).toEqual([
-      "user",
-      "assistant",
-    ]);
-  });
-
  it("batches answer deltas into one animation-frame update", async () => {
    const fake = fakeClient();
    const requestFrame = vi.spyOn(window, "requestAnimationFrame");
@@ -2029,6 +1919,44 @@ describe("useNanobotStream", () => {
    expect(result.current.runStartedAt).toBe(1_700_000_000);
  });

+  it("projects a cross-session input with its public handle exactly once", () => {
+    const fake = fakeClient();
+    const { result } = renderHook(
+      () => useNanobotStream("chat-target", EMPTY_MESSAGES),
+      { wrapper: wrap(fake.client) },
+    );
+    const event: InboundEvent = {
+      event: "user_message",
+      chat_id: "chat-target",
+      text: "Please review this.",
+      created_at_ms: 1_700_000_000_123,
+      starts_turn: false,
+      provenance: {
+        session_message: {
+          message_id: "message-1",
+          session: {
+            id: "handle_0123456789abcdef0123456789abcdef",
+            name: "mira-0123456789",
+          },
+        },
+      },
+    };
+
+    act(() => {
+      fake.emit("chat-target", event);
+      fake.emit("chat-target", event);
+    });
+
+    expect(result.current.messages).toEqual([expect.objectContaining({
+      id: "session-message:message-1",
+      role: "user",
+      content: "Please review this.",
+      createdAt: 1_700_000_000_123,
+      sessionMessage: event.provenance?.session_message,
+    })]);
+    expect(result.current.isStreaming).toBe(true);
+  });
+
  it("marks only the optimistic turn named by a correlated rejection as failed", () => {
    const fake = fakeClient();
    const { result } = renderHook(
@@ -2975,28 +2903,6 @@ describe("useNanobotStream", () => {
    expect(result.current.isStreaming).toBe(false);
  });

-  it("clears the pane timer when canonical reconciliation settles the client run", () => {
-    const fake = fakeClient();
-    const { result } = renderHook(() => useNanobotStream("chat-g", EMPTY_MESSAGES), {
-      wrapper: wrap(fake.client),
-    });
-
-    act(() => {
-      fake.emit("chat-g", {
-        event: "goal_status",
-        chat_id: "chat-g",
-        status: "running",
-        started_at: 1700,
-        turn_id: "handle:turn-1",
-      });
-    });
-    expect(result.current.runStartedAt).toBe(1700);
-
-    act(() => fake.emitRunStatus("chat-g", null));
-
-    expect(result.current.runStartedAt).toBeNull();
-  });
-
  it("restores runStartedAt after switching away and back when goal_status was recorded without a subscriber", () => {
    const fake = fakeClient();
    const { result, rerender } = renderHook(