stacklok · jtenniswood · Sep 2, 2026
diff --git a/docs/design/PRODUCTION-READINESS.md b/docs/design/PRODUCTION-READINESS.md
@@ -46,7 +46,7 @@ record; current behaviour is in the linked [architecture](../architecture.md) do
 | mecak8s (storage-free k8s-native agent) | ✅ shipped (MVP) · ✅ OPT-IN `/metrics` loopback scrape + OTLP push (ADR 0098) · ✅ verified external Redis TLS/ACL with transactional projected-file reload + last-valid generations (ADR 0240) · ✅ Helm 0.3.0 secure real-provider in-pod TLS+OIDC or edge-terminated TLS+OIDC (ClusterIP h2c), nullable spend ceilings, and pod scheduling controls · ⛔ CRD/Operator · ⛔ HPA (custom-metrics on active-runs) · ⛔ managed Redis provisioning (ElastiCache/MemoryStore — endpoint only) · ⛔ fix `mecated`'s unbounded `GracefulStop` (pre-existing, follow-up) | [mecak8s.md](../adr/0048-mecak8s.md) · [0098](../adr/0098-headless-telemetry.md) · [0240](../adr/0240-mecak8s-credential-reload-and-chart-security.md) · [0278](../adr/0278-mecak8s-edge-terminated-tls.md) · [MECAK8S-PLAN.md](./MECAK8S-PLAN.md) | [overview](../architecture.md) |
 | ACP adapter (editor stdio surface) | ✅ Phase 1+2 + bounded Phase 3 + multimodal shipped · ⛔ Phase 3 long-tail (rule persistence, grep-over-buffers, fs/* on resume) | [0001-acp-adapter.md](../adr/0001-acp-adapter.md) | [api surface](../architecture/api-surface.md) |
 | Conversation fork (peer session from a history snapshot) | ✅ shipped · ✅ effort override (mid-conversation effort switch, keeps the transcript — [0068](../adr/0068-effort-change-via-fork.md)) · ⛔ cross-provider/model fork (v2: replay-blob stripping) · ⛔ workspace-branching fork · ⛔ fork-from-event-log-at-arbitrary-point · ⛔ fork lineage (`forked_from` label) | [0065-conversation-fork.md](../adr/0065-conversation-fork.md) | [overview](../architecture.md) |
-| Studio (web client) | 🚧 landing as a stacked PR series: ✅ module foundation (vendored Atrium UI kit, toolchain, CI gates) · ✅ server tier (trusted proxy + managed-mode controller core, hermetic suite) · ✅ protocol seam + harness transport · ✅ workspace shell + runtime status · ✅ Chats core + hermetic browser e2e (fixture daemon) · ✅ Scheduled (authoring, carried-spec edit, fire log + per-fire transcripts) · ✅ Skills (browse/create/upload/enable-disable, controller-mediated; learned-skills panel) · ✅ Memory (read-only table + detail + consolidate, honest disabled/empty states) · ✅ Settings core (Personalize, agent identity, learning review) · ✅ provider management + model router + MCP gateway (controller-mediated; server-side auth.yaml ownership, no key material on the wire) · ✅ external-mode OIDC sign-in (PKCE, server-held tokens) · ✅ advanced chat: attachments/previews, tool drill-down + context meter + typed retry + live delegation cards, queue + steer, threads + canvas, live re-attach via the session watch (residual: the driving tab's prompt stream still cancels on disconnect) · ✅ session modes + fork-based mid-chat model switch + consented debug-with-AI (ADR 0254) · ⛔ Labs · ⛔ mobile round · ⛔ advanced chat tiers (attachments, steer/queue, threads, re-attach, modes, mobile) | [0288](../adr/0288-studio-atrium-module.md) · [0289](../adr/0289-studio-server-backed-chats.md) | [overview](../architecture.md) |
+| Studio (web client) | 🚧 landing as a stacked PR series: ✅ module foundation (vendored Atrium UI kit, toolchain, CI gates) · ✅ server tier (trusted proxy + managed-mode controller core, hermetic suite) · ✅ protocol seam + harness transport · ✅ workspace shell + runtime status · ✅ Chats core + hermetic browser e2e (fixture daemon) · ✅ Scheduled (authoring, carried-spec edit, fire log + per-fire transcripts) · ✅ Skills (browse/create/upload/enable-disable, controller-mediated; learned-skills panel) · ✅ Memory (read-only table + detail + consolidate, honest disabled/empty states) · ✅ Settings core (Personalize, agent identity, learning review) · ✅ provider management + model router + MCP gateway (controller-mediated; server-side auth.yaml ownership, no key material on the wire) · ✅ external-mode OIDC sign-in (PKCE, server-held tokens) · ✅ advanced chat: attachments/previews, tool drill-down + context meter + typed retry + live delegation cards, queue + steer, threads + canvas, live re-attach via the session watch (residual: the driving tab's prompt stream still cancels on disconnect) · ✅ session modes + fork-based mid-chat model switch + consented debug-with-AI (ADR 0254) · ✅ Labs mock Projects + feature tour (default-off; mock ids hard-gated from the daemon) · ⛔ mobile round · ⛔ advanced chat tiers (attachments, steer/queue, threads, re-attach, modes, mobile) | [0288](../adr/0288-studio-atrium-module.md) · [0289](../adr/0289-studio-server-backed-chats.md) | [overview](../architecture.md) |
 | _Historical / retired_ | — | [ARCHITECTURE.md](../adr/0004-v1-architecture.md) · [STEP-CHAIN.md](../adr/0006-v1-step-chain.md) · [TWELVE-PATTERNS-AUDIT.md](../adr/0007-twelve-patterns-audit.md) · [REPOMAP-TREE-SITTER.md](../adr/0029-repomap-tree-sitter.md) | — |
 
 ## Security

diff --git a/studio/src/app/workspace/_components/chat-input.tsx b/studio/src/app/workspace/_components/chat-input.tsx
@@ -9,6 +9,8 @@ import {
   Bot,
   Check,
   ChevronDown,
+  FolderClosed,
+  FolderPlus,
   Mic,
   Paperclip,
   Plus,
@@ -19,7 +21,9 @@ import { Button } from "@/components/ui/button";
 import {
   DropdownMenu,
   DropdownMenuContent,
+  DropdownMenuGroup,
   DropdownMenuItem,
+  DropdownMenuLabel,
   DropdownMenuSeparator,
   DropdownMenuSub,
   DropdownMenuSubContent,
@@ -30,6 +34,7 @@ import {
   getAgentMentions,
   getSlashCommands,
 } from "@/features/agent/composer-capabilities";
+import { usePrompt } from "@/hooks/use-prompt";
 import { fileKindMeta } from "@/lib/file-meta";
 import {
   type EnterSendBehavior,
@@ -44,9 +49,19 @@ import {
   setComposerText,
 } from "./composer-mentions";
 
+interface ProjectItem {
+  id: string;
+  name: string;
+  color: string;
+}
+
 interface ChatInputProps {
   placeholder?: string;
   rows?: number;
+  projects?: ProjectItem[];
+  selectedProjectId?: string | null;
+  onSelectProject?: (id: string | null) => void;
+  onCreateProject?: (name: string) => void;
   compact?: boolean;
   onSend?: (content: string, files?: File[]) => void;
   onQueue?: (content: string) => void;
@@ -473,6 +488,80 @@ function MemoryToggle() {
   );
 }
 
+function ProjectsDropdown({
+  projects,
+  selectedProjectId,
+  onSelect,
+  onCreate,
+}: {
+  projects?: ProjectItem[];
+  selectedProjectId?: string | null;
+  onSelect?: (id: string | null) => void;
+  onCreate?: (name: string) => void;
+}) {
+  const { prompt, PromptDialog } = usePrompt();
+  const selected = projects?.find((p) => p.id === selectedProjectId);
+
+  return (
+    <>
+      {PromptDialog}
+      <DropdownMenu>
+        <DropdownMenuTrigger asChild>
+          <Button size="sm" className={GHOST_TRIGGER_CLASS}>
+            <FolderClosed className="size-3.5 text-muted-foreground" />
+            {selected ? selected.name : "Project"}
+            <ChevronDown className="size-3.5 text-muted-foreground" />
+          </Button>
+        </DropdownMenuTrigger>
+        <DropdownMenuContent
+          onCloseAutoFocus={(e) => e.preventDefault()}
+          align="start"
+          className="w-56"
+        >
+          <DropdownMenuLabel>Projects</DropdownMenuLabel>
+          <DropdownMenuSeparator />
+          <DropdownMenuGroup>
+            <DropdownMenuItem onClick={() => onSelect?.(null)}>
+              <span className={cn(!selectedProjectId && "font-semibold")}>
+                Chats
+              </span>
+            </DropdownMenuItem>
+            {projects?.map((p) => (
+              <DropdownMenuItem key={p.id} onClick={() => onSelect?.(p.id)}>
+                <FolderClosed className="size-3.5 shrink-0 mr-1.5 text-muted-foreground" />
+                <span
+                  className={cn(
+                    "truncate",
+                    p.id === selectedProjectId && "font-semibold",
+                  )}
+                >
+                  {p.name}
+                </span>
+              </DropdownMenuItem>
+            ))}
+          </DropdownMenuGroup>
+          <DropdownMenuSeparator />
+          <DropdownMenuItem
+            onClick={async () => {
+              const name = await prompt({
+                title: "New project",
+                description:
+                  "Give your project a name to organize related conversations.",
+                placeholder: "Project name",
+                confirmText: "Create project",
+              });
+              if (name) onCreate?.(name);
+            }}
+          >
+            <FolderPlus className="size-3.5 mr-2" />
+            New project
+          </DropdownMenuItem>
+        </DropdownMenuContent>
+      </DropdownMenu>
+    </>
+  );
+}
+
 function useVoiceInput(onTranscript: (text: string) => void) {
   const [isListening, setIsListening] = useState(false);
   const [isSupported, setIsSupported] = useState(false);
@@ -723,6 +812,10 @@ function handleMenuNavKey(
 
 export function ChatInput({
   placeholder: placeholderProp,
+  projects,
+  selectedProjectId,
+  onSelectProject,
+  onCreateProject,
   compact = false,
   onSend,
   onQueue,
@@ -1167,6 +1260,14 @@ export function ChatInput({
           container queries when THIS row runs narrow (a ~400px side-panel
           composer), independent of the viewport width. */}
       <div className="@container -mt-4 pt-5 px-2 pb-1.5 flex items-center gap-1 rounded-b-2xl border border-t-0 border-zinc-300 dark:border-zinc-700 bg-zinc-50 dark:bg-zinc-900 overflow-x-auto hide-scrollbar">
+        {projects && (
+          <ProjectsDropdown
+            projects={projects}
+            selectedProjectId={selectedProjectId}
+            onSelect={onSelectProject}
+            onCreate={onCreateProject}
+          />
+        )}
         {!compact && (
           <>
             {onModeChange && (

diff --git a/studio/src/app/workspace/chat/_components/chat-view.tsx b/studio/src/app/workspace/chat/_components/chat-view.tsx
@@ -45,6 +45,7 @@ import {
   useAgentChat,
 } from "@/features/agent";
 import type { QueuedMessage } from "@/features/agent/hooks/use-agent-chat";
+import { isMockTourSession } from "@/features/agent/mock-tour";
 import { formatTokens } from "@/lib/formatters";
 import {
   createThreadHarnessSession,
@@ -368,6 +369,9 @@ function ThreadPanel({
 
   const handleSend = useCallback(
     async (content: string, files?: File[]) => {
+      // Defense in depth: a mock session id must never mint a daemon thread
+      // session (the panel router already sends mock threads elsewhere).
+      if (isMockTourSession(parentSessionId)) return;
       setSourceBusy(false);
       setCreateError(null);
       if (threadIdRef.current) {
@@ -550,6 +554,57 @@ function ThreadPanel({
   );
 }
 
+/**
+ * The thread panel for the Labs mock chat: a read-only view of the root
+ * message's canned replies. Entirely local — a mock session id must never
+ * mint a daemon thread session, so this replaces ThreadPanel outright.
+ */
+function MockThreadPanel({
+  rootMessage,
+  botName,
+  onClose,
+  maximized,
+  onToggleMaximize,
+}: {
+  rootMessage: AgentMessage;
+  botName: string;
+  onClose: () => void;
+  maximized: boolean;
+  onToggleMaximize: () => void;
+}) {
+  const replies = rootMessage.replies ?? [];
+  return (
+    <SidePanel
+      icon={MessageSquareText}
+      title="Thread"
+      closeLabel="Close thread"
+      maximized={maximized}
+      onToggleMaximize={onToggleMaximize}
+      onClose={onClose}
+      minWidth={340}
+    >
+      <div className="flex-1 min-h-0 overflow-y-auto px-3 pt-3 pb-4 lg:px-4">
+        <div className="rounded-lg border border-dashed border-border/70 px-1 py-1">
+          <MessageBubble message={rootMessage} botName={botName} />
+        </div>
+        {replies.length > 0 && (
+          <div className="my-2 flex items-center gap-2 px-2 text-[11px] font-medium uppercase tracking-wide text-muted-foreground/70">
+            <span className="h-px flex-1 bg-border" />
+            {replies.length} {replies.length === 1 ? "reply" : "replies"}
+            <span className="h-px flex-1 bg-border" />
+          </div>
+        )}
+        {replies.map((reply) => (
+          <MessageBubble key={reply.id} message={reply} botName={botName} />
+        ))}
+        <p className="px-2 pt-2 text-xs text-muted-foreground">
+          Mock thread &mdash; read-only demo content.
+        </p>
+      </div>
+    </SidePanel>
+  );
+}
+
 function TextSelectionToolbar({
   containerRef,
   onAddToChat,
@@ -690,6 +745,7 @@ export function ChatView({
   onCancelRun,
   onCompact,
   contextInfo,
+  readOnlyPlaceholder,
   mode,
   onModeChange,
   models,
@@ -746,6 +802,9 @@ export function ChatView({
   /** The session's effective model + context window (B1.1): feeds the slim
       approximate context meter near the composer. */
   contextInfo?: { modelLabel: string; contextWindow: number } | null;
+  /** Disables the composer and shows this placeholder instead (the Labs
+      mock chat is read-only demo content). */
+  readOnlyPlaceholder?: string;
   /** The session's current permission mode, for the composer's Mode selector. */
   mode?: SessionPermissionMode;
   /** Renders the composer's Mode selector when provided (the mock tour chat
@@ -1131,7 +1190,7 @@ export function ChatView({
                   mode={mode}
                   onModeChange={onModeChange}
                   isStreaming={isStreaming}
-                  disabled={!!pendingApproval}
+                  disabled={!!pendingApproval || readOnlyPlaceholder != null}
                   appendText={appendText}
                   onAppendConsumed={handleAppendConsumed}
                   initialText={editSeed ?? initialDraft}
@@ -1140,13 +1199,14 @@ export function ChatView({
                     else onInitialDraftConsumed?.();
                   }}
                   placeholder={
-                    isStreaming
+                    readOnlyPlaceholder ??
+                    (isStreaming
                       ? // "Steer" is only an honest promise while the daemon
                         // actually supports it (C1.2) — absent, sends queue.
                         enterBehavior === "steer" && onSteerMessage
                         ? "Steer the agent..."
                         : "Queue a message..."
-                      : "Send a message..."
+                      : "Send a message...")
                   }
                 />
               )}
@@ -1196,6 +1256,16 @@ function SidePanelForKind({
     case "toolcall":
       return <ToolCallPanel call={panel.call} {...shared} />;
     case "thread":
+      // Mock chat threads stay local: read-only replies, no daemon session.
+      if (isMockTourSession(parentSessionId)) {
+        return (
+          <MockThreadPanel
+            rootMessage={panel.message}
+            botName={botName}
+            {...shared}
+          />
+        );
+      }
       return (
         <ThreadPanel
           // Re-key per root message: switching threads must remount the