Remove agent directory syncing, make it pure derived state

Problem: Agent directory was still being synced from SessionProvider to
Zustand store, violating the "SessionProvider is just a message handler"
principle and creating unnecessary state duplication.

Solution: Make agent directory pure derived state:
- Removed agentDirectory from SessionStoreState
- Removed setAgentDirectory/clearAgentDirectory actions
- Changed getAgentDirectory to compute on-demand from session.agents
- Removed buildAgentDirectoryEntries and syncing from SessionProvider
- Updated useAggregatedAgents to derive from sessions directly

How it works now:
- Agent directory is computed on-demand from session.agents Map
- lastActivityAt automatically updates when agents update via WebSocket
- No syncing, no stale state, no overhead
- Single source of truth: session.agents

Benefits:
- Eliminated redundant state (agentDirectory was duplicate of agents)
- No sync overhead or complexity
- Always fresh data (derived on read)
- Simpler mental model (agents is the only source)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/app/src/contexts/session-context.tsx

@@ -137,22 +137,6 @@ function normalizeAgentSnapshot(snapshot: AgentSnapshotPayload, serverId: string
   };
 }
 
-function buildAgentDirectoryEntries(serverId: string, agents: Map<string, any>): AgentDirectoryEntry[] {
-  const entries: AgentDirectoryEntry[] = [];
-  for (const agent of agents.values()) {
-    entries.push({
-      id: agent.id,
-      serverId,
-      title: agent.title ?? null,
-      status: agent.status,
-      lastActivityAt: agent.lastActivityAt,
-      cwd: agent.cwd,
-      provider: agent.provider,
-    });
-  }
-  return entries;
-}
-
 const createExplorerState = () => ({
   directories: new Map(),
   files: new Map(),
@@ -231,8 +215,6 @@ export function SessionProvider({ children, serverUrl, serverId }: SessionProvid
   // Zustand store actions
   const initializeSession = useSessionStore((state) => state.initializeSession);
   const clearSession = useSessionStore((state) => state.clearSession);
-  const setAgentDirectory = useSessionStore((state) => state.setAgentDirectory);
-  const clearAgentDirectory = useSessionStore((state) => state.clearAgentDirectory);
   const setIsPlayingAudio = useSessionStore((state) => state.setIsPlayingAudio);
   const setMessages = useSessionStore((state) => state.setMessages);
   const setCurrentAssistantMessage = useSessionStore((state) => state.setCurrentAssistantMessage);
@@ -1087,14 +1069,6 @@ export function SessionProvider({ children, serverUrl, serverId }: SessionProvid
     };
   }, [ws, audioPlayer, serverId, setIsPlayingAudio, setMessages, setCurrentAssistantMessage, setAgentStreamState, setInitializingAgents, setAgents, setCommands, setPendingPermissions, setGitDiffs, setFileExplorer, setProviderModels, setHasHydratedAgents, updateConnectionStatus, getSession, saveDraftInput]);
 
-  // Sync agent directory
-  useEffect(() => {
-    const session = getSession(serverId);
-    if (!session) return;
-    const lightweightAgentDirectory = buildAgentDirectoryEntries(serverId, session.agents);
-    setAgentDirectory(serverId, lightweightAgentDirectory);
-  }, [serverId, getSession, setAgentDirectory]);
-
   // Auto-flush queued messages when agent transitions from running -> not running
   useEffect(() => {
     const session = getSession(serverId);
@@ -1546,9 +1520,8 @@ export function SessionProvider({ children, serverUrl, serverId }: SessionProvid
   useEffect(() => {
     return () => {
       clearSession(serverId);
-      clearAgentDirectory(serverId);
     };
-  }, [serverId, clearSession, clearAgentDirectory]);
+  }, [serverId, clearSession]);
 
   const value = useMemo<SessionContextValue>(
     () => ({

packages/app/src/hooks/use-aggregated-agents.ts

@@ -15,21 +15,27 @@ export interface AggregatedAgentsResult {
 
 export function useAggregatedAgents(): AggregatedAgentsResult {
   const { connectionStates } = useDaemonConnections();
-  const agentDirectory = useSessionStore((state) => state.agentDirectory);
+  const sessions = useSessionStore((state) => state.sessions);
 
   return useMemo(() => {
     const allAgents: AggregatedAgent[] = [];
 
-    for (const [serverId, agents] of Object.entries(agentDirectory)) {
-      if (!agents || agents.length === 0) {
+    // Derive agent directory from all sessions
+    for (const [serverId, session] of Object.entries(sessions)) {
+      if (!session?.agents || session.agents.size === 0) {
         continue;
       }
       const serverLabel = connectionStates.get(serverId)?.daemon.label ?? serverId;
-      for (const agent of agents) {
+      for (const agent of session.agents.values()) {
         allAgents.push({
-          ...agent,
+          id: agent.id,
           serverId,
           serverLabel,
+          title: agent.title ?? null,
+          status: agent.status,
+          lastActivityAt: agent.lastActivityAt,
+          cwd: agent.cwd,
+          provider: agent.provider,
         });
       }
     }
@@ -61,5 +67,5 @@ export function useAggregatedAgents(): AggregatedAgentsResult {
     });
 
     return { agents: allAgents, isLoading };
-  }, [agentDirectory, connectionStates]);
+  }, [sessions, connectionStates]);
 }

packages/app/src/stores/session-store.ts

@@ -203,7 +203,6 @@ export interface SessionState {
 // Global store state
 interface SessionStoreState {
   sessions: Record<string, SessionState>;
-  agentDirectory: Record<string, AgentDirectoryEntry[]>;
 }
 
 // Action types
@@ -257,9 +256,7 @@ interface SessionStoreActions {
   // Hydration
   setHasHydratedAgents: (serverId: string, hydrated: boolean) => void;
 
-  // Agent directory
-  setAgentDirectory: (serverId: string, agents: AgentDirectoryEntry[]) => void;
-  clearAgentDirectory: (serverId: string) => void;
+  // Agent directory (derived from agents)
   getAgentDirectory: (serverId: string) => AgentDirectoryEntry[] | undefined;
 }
 
@@ -288,29 +285,6 @@ function logSessionStoreUpdate(
   });
 }
 
-function areAgentDirectoriesEqual(left: AgentDirectoryEntry[] | undefined, right: AgentDirectoryEntry[]): boolean {
-  if (!left) {
-    return false;
-  }
-  if (left.length !== right.length) {
-    return false;
-  }
-  return left.every((entry, index) => {
-    const other = right[index];
-    if (!other) {
-      return false;
-    }
-    return (
-      entry.id === other.id &&
-      entry.status === other.status &&
-      entry.serverId === other.serverId &&
-      entry.lastActivityAt.getTime() === other.lastActivityAt.getTime() &&
-      entry.title === other.title &&
-      entry.cwd === other.cwd &&
-      entry.provider === other.provider
-    );
-  });
-}
 
 // Helper to create initial session state
 function createInitialSessionState(serverId: string, ws: UseWebSocketReturn, audioPlayer: ReturnType<typeof useAudioPlayer>): SessionState {
@@ -339,7 +313,6 @@ function createInitialSessionState(serverId: string, ws: UseWebSocketReturn, aud
 export const useSessionStore = create<SessionStore>()(
   subscribeWithSelector((set, get) => ({
     sessions: {},
-    agentDirectory: {},
 
     // Session management
     initializeSession: (serverId, ws, audioPlayer) => {
@@ -697,38 +670,26 @@ export const useSessionStore = create<SessionStore>()(
       });
     },
 
-    // Agent directory
-    setAgentDirectory: (serverId, agents) => {
-      set((prev) => {
-        const existing = prev.agentDirectory[serverId];
-        if (existing && areAgentDirectoriesEqual(existing, agents)) {
-          return prev;
-        }
-        logSessionStoreUpdate("setAgentDirectory", serverId, { agentCount: agents.length });
-        return {
-          ...prev,
-          agentDirectory: {
-            ...prev.agentDirectory,
-            [serverId]: agents,
-          },
-        };
-      });
-    },
-
-    clearAgentDirectory: (serverId) => {
-      set((prev) => {
-        if (!(serverId in prev.agentDirectory)) {
-          return prev;
-        }
-        logSessionStoreUpdate("clearAgentDirectory", serverId);
-        const nextDirectory = { ...prev.agentDirectory };
-        delete nextDirectory[serverId];
-        return { ...prev, agentDirectory: nextDirectory };
-      });
-    },
-
+    // Agent directory - derived from agents (computed on-demand)
     getAgentDirectory: (serverId) => {
-      return get().agentDirectory[serverId];
+      const session = get().sessions[serverId];
+      if (!session) {
+        return undefined;
+      }
+
+      const entries: AgentDirectoryEntry[] = [];
+      for (const agent of session.agents.values()) {
+        entries.push({
+          id: agent.id,
+          serverId,
+          title: agent.title ?? null,
+          status: agent.status,
+          lastActivityAt: agent.lastActivityAt,
+          cwd: agent.cwd,
+          provider: agent.provider,
+        });
+      }
+      return entries;
     },
   }))
 );