feat: expose per-session window list in sidebar

apps/tui/src/index.tsx

@@ -313,6 +313,13 @@ function App() {
     send({ type: "switch-session", name });
   }
 
+  function switchToWindow(sessionName: string, windowIndex: number) {
+    setCurrentSession(sessionName);
+    setFocusedSession(sessionName);
+    setPanelFocus("sessions");
+    send({ type: "switch-window", sessionName, windowIndex });
+  }
+
   function reIdentify() {
     const sessionName = getLocalSessionName();
     if (!sessionName) return;
@@ -881,6 +888,9 @@ function App() {
                 send({ type: "focus-session", name: session.name });
                 switchToSession(session.name);
               }}
+              onSwitchWindow={(windowIndex) => {
+                switchToWindow(session.name, windowIndex);
+              }}
             />
           )}
         </For>
@@ -1514,6 +1524,7 @@ interface SessionCardProps {
   theme: Accessor<Theme>;
   statusColors: Accessor<Theme["status"]>;
   onSelect: () => void;
+  onSwitchWindow?: (windowIndex: number) => void;
 }
 
 function SessionCard(props: SessionCardProps) {
@@ -1685,6 +1696,50 @@ function SessionCard(props: SessionCardProps) {
               <span style={{ fg: toneColor(metaTone(), P()), attributes: DIM }}>{metaSummary()}</span>
             </text>
           </Show>
+
+          {/* Row 4: window/tab list (when session has >1 window) */}
+          <Show when={(props.session.windowList?.length ?? 0) > 1}>
+            <For each={props.session.windowList}>
+              {(win) => {
+                const winAgentIcon = () => {
+                  const s = (win as any).agentStatus;
+                  if (!s) return "";
+                  if (s === "idle") return "○";
+                  if (s === "running") return SPINNERS[props.spinIdx() % SPINNERS.length]!;
+                  if (s === "tool-running") return "⚙";
+                  if (s === "done") return "✓";
+                  if (s === "error") return "✗";
+                  if (s === "waiting") return "◉";
+                  if (s === "interrupted" || s === "stale") return "⚠";
+                  return "";
+                };
+                const winAgentColor = () => {
+                  const s = (win as any).agentStatus;
+                  if (!s) return "";
+                  if (s === "idle") return P().surface2;
+                  return SC()[s] ?? P().overlay0;
+                };
+                return (
+                  <box flexDirection="row">
+                    <text truncate wrapMode="none" flexGrow={1}
+                      onMouseDown={() => {
+                        props.onSwitchWindow?.(win.index);
+                      }}
+                      fg={win.active ? P().green : P().overlay0}>
+                      <span style={{ fg: win.active ? P().green : P().overlay0 }}>
+                        {`  ${win.active ? "▸" : " "} ${win.index}:${win.name}`}
+                      </span>
+                    </text>
+                    <Show when={winAgentIcon()}>
+                      <text flexShrink={0}>
+                        <span style={{ fg: winAgentColor() }}>{" "}{winAgentIcon()}</span>
+                      </text>
+                    </Show>
+                  </box>
+                );
+              }}
+            </For>
+          </Show>
         </box>
       </box>
 

packages/mux/contract/src/index.ts

@@ -1,6 +1,7 @@
 // ─── Types ───────────────────────────────────────────────────────────────────
 export type {
   MuxSpecificationVersion,
+  MuxWindowInfo,
   MuxSessionInfo,
   ActiveWindow,
   SidebarPane,

packages/mux/contract/src/types.ts

@@ -5,11 +5,20 @@ export type MuxSpecificationVersion = "v1";
 
 // ─── Core data types ─────────────────────────────────────────────────────────
 
+export interface MuxWindowInfo {
+  readonly id: string;
+  readonly index: number;
+  readonly name: string;
+  readonly active: boolean;
+  readonly paneCount: number;
+}
+
 export interface MuxSessionInfo {
   readonly name: string;
   readonly createdAt: number;
   readonly dir: string;
   readonly windows: number;
+  readonly windowList?: readonly MuxWindowInfo[];
 }
 
 export interface ActiveWindow {

packages/mux/providers/tmux/src/provider.ts

@@ -48,11 +48,26 @@ export class TmuxProvider implements MuxProviderV1, WindowCapable, SidebarCapabl
     const sessions = tmux.listSessions()
       .filter((s) => s.name !== STASH_SESSION);
     const activeDirs = tmux.getActiveSessionDirs();
+    const allWindows = tmux.listWindows();
+    const windowsBySession = new Map<string, typeof allWindows>();
+    for (const w of allWindows) {
+      if (w.sessionName === STASH_SESSION) continue;
+      let list = windowsBySession.get(w.sessionName);
+      if (!list) { list = []; windowsBySession.set(w.sessionName, list); }
+      list.push(w);
+    }
     return sessions.map((s) => ({
       name: s.name,
       createdAt: s.createdAt,
       dir: activeDirs.get(s.name) ?? s.dir,
       windows: s.windowCount,
+      windowList: (windowsBySession.get(s.name) ?? []).map((w) => ({
+        id: w.id,
+        index: w.index,
+        name: w.name,
+        active: w.active,
+        paneCount: w.paneCount,
+      })),
     }));
   }
 

packages/runtime/src/contracts/index.ts

@@ -1,3 +1,3 @@
 export type { AgentStatus, AgentEvent } from "./agent";
 export { TERMINAL_STATUSES } from "./agent";
-export type { MuxProvider, MuxSessionInfo } from "./mux";
+export type { MuxProvider, MuxWindowInfo, MuxSessionInfo } from "./mux";

packages/runtime/src/contracts/mux.ts

@@ -1,5 +1,6 @@
 export type {
   MuxSpecificationVersion,
+  MuxWindowInfo,
   MuxSessionInfo,
   ActiveWindow,
   SidebarPane,

packages/runtime/src/index.ts

@@ -1,6 +1,7 @@
 export type {
   MuxProvider,
   MuxProviderV1,
+  MuxWindowInfo,
   MuxSessionInfo,
   ActiveWindow,
   SidebarPane,
@@ -48,6 +49,7 @@ export {
 } from "./shared";
 export type {
   SessionData,
+  WindowData,
   ServerState,
   FocusUpdate,
   ResizeNotify,

packages/runtime/src/server/index.ts

@@ -525,7 +525,18 @@ export function startServer(mux: MuxProvider, extraProviders?: MuxProvider[], wa
       }
     }
 
-    const sessions: SessionData[] = orderedMuxSessions.map(({ name, createdAt, windows, dir, provider }) => {
+    // Build paneId -> windowId map for agent-to-window association
+    const paneToWindow = new Map<string, string>();
+    try {
+      const raw = shell(["tmux", "list-panes", "-a", "-F", "#{pane_id}|#{window_id}"]);
+      for (const line of raw.split("\n")) {
+        if (!line) continue;
+        const sep = line.indexOf("|");
+        if (sep > 0) paneToWindow.set(line.slice(0, sep), line.slice(sep + 1));
+      }
+    } catch {}
+
+    const sessions: SessionData[] = orderedMuxSessions.map(({ name, createdAt, windows, windowList, dir, provider }) => {
       sessionProviders.set(name, provider);
       const git = getGitInfo(dir);
       const providerPaneCounts = paneCountMaps.get(provider);
@@ -554,6 +565,15 @@ export function startServer(mux: MuxProvider, extraProviders?: MuxProvider[], wa
         ports: getSessionPorts(name),
         localLinks: buildLocalLinks(getSessionPorts(name), portlessState),
         windows,
+        windowList: (windowList ?? []).map((w) => {
+          const agents = tracker.getAgents(name);
+          const windowAgent = agents.find((a) => a.paneId && paneToWindow.get(a.paneId) === w.id);
+          return {
+            ...w,
+            agentStatus: windowAgent?.status,
+            agentName: windowAgent?.agent,
+          };
+        }),
         uptime,
         agentState: tracker.getState(name),
         agents: tracker.getAgents(name),
@@ -1455,6 +1475,24 @@ export function startServer(mux: MuxProvider, extraProviders?: MuxProvider[], wa
         }
         break;
       }
+      case "switch-window": {
+        const clientSess = clientSessionNames.get(ws);
+        const tty = (clientSess ? clientTtyBySession.get(clientSess) : undefined)
+          ?? cmd.clientTty ?? clientTtys.get(ws);
+        const p = sessionProviders.get(cmd.sessionName) ?? mux;
+        p.switchSession(cmd.sessionName, tty);
+        // Select the target window by index
+        try {
+          Bun.spawnSync(["tmux", "select-window", "-t", `${cmd.sessionName}:${cmd.windowIndex}`], {
+            stdout: "pipe", stderr: "pipe",
+          });
+        } catch {}
+        focusedSession = cmd.sessionName;
+        cachedCurrentSession = cmd.sessionName;
+        cachedCurrentSessionTs = Date.now();
+        broadcastFocusOnly();
+        break;
+      }
       case "switch-index": {
         const clientSess = clientSessionNames.get(ws);
         const tty = (clientSess ? clientTtyBySession.get(clientSess) : undefined)

packages/runtime/src/shared.ts

@@ -1,5 +1,5 @@
 import type { AgentStatus, AgentEvent } from "./contracts/agent";
-import type { MuxSessionInfo } from "./contracts/mux";
+import type { MuxSessionInfo, MuxWindowInfo } from "./contracts/mux";
 import type { SessionFilterMode } from "./config";
 
 export const SERVER_PORT = 7391;
@@ -15,6 +15,11 @@ export interface LocalLink {
   label: string;
 }
 
+export interface WindowData extends MuxWindowInfo {
+  agentStatus?: AgentStatus;
+  agentName?: string;
+}
+
 export interface SessionData {
   name: string;
   createdAt: number;
@@ -27,6 +32,7 @@ export interface SessionData {
   ports: number[];
   localLinks: LocalLink[];
   windows: number;
+  windowList: WindowData[];
   uptime: string;
   agentState: AgentEvent | null;
   agents: AgentEvent[];
@@ -107,6 +113,7 @@ export interface SessionMetadata {
 
 export type ClientCommand =
   | { type: "switch-session"; name: string; clientTty?: string }
+  | { type: "switch-window"; sessionName: string; windowIndex: number; clientTty?: string }
   | { type: "switch-index"; index: number }
   | { type: "new-session" }
   | { type: "hide-session"; name: string }