diff --git a/packages/web-shell/client/App.test.tsx b/packages/web-shell/client/App.test.tsx
index 75fcc7a333e..24c8a1b42a6 100644
--- a/packages/web-shell/client/App.test.tsx
+++ b/packages/web-shell/client/App.test.tsx
@@ -3532,6 +3532,161 @@ describe('App session callbacks', () => {
     );
   });
 
+  it('reports the selected workspace, not the stale connection workspace, when no session is active', async () => {
+    // A cleared session leaves connection.workspaceCwd pointing at the old
+    // workspace (here: a secondary with a running task). Starting a new chat
+    // in the primary must report the primary, not route the host back to the
+    // stale workspace.
+    mockConnection.sessionId = undefined;
+    mockConnection.workspaceCwd = '/work/secondary';
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    };
+    const onSessionIdChange = vi.fn();
+
+    renderApp({
+      onSessionIdChange,
+      initialSelectedWorkspaceCwd: '/workspace',
+    });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenCalledWith(
+      undefined,
+      undefined,
+      '/workspace',
+    );
+    expect(onSessionIdChange).not.toHaveBeenCalledWith(
+      undefined,
+      'secondary',
+      '/work/secondary',
+    );
+  });
+
+  it('reports the primary workspace, not the stale connection workspace, when the selection is unset', async () => {
+    // The common new-chat path (sidebar "New task", /clear, /new) leaves
+    // selectedWorkspaceCwd undefined — that is how "primary" is spelled. The
+    // report must fall back to the primary workspace, not the stale
+    // connection.workspaceCwd left over from the previous session.
+    mockConnection.sessionId = undefined;
+    mockConnection.workspaceCwd = '/work/secondary';
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    };
+    const onSessionIdChange = vi.fn();
+
+    renderApp({ onSessionIdChange });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenCalledWith(
+      undefined,
+      undefined,
+      '/workspace',
+    );
+    expect(onSessionIdChange).not.toHaveBeenCalledWith(
+      undefined,
+      'secondary',
+      '/work/secondary',
+    );
+  });
+
+  it('keeps reporting the active session workspace despite a conflicting next-session selection', async () => {
+    // A selection for the next session must not leak into an active session's
+    // report: while a session is live the host is routed by that session's own
+    // workspace.
+    mockConnection.workspaceCwd = '/work/secondary';
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    };
+    const onSessionIdChange = vi.fn();
+
+    renderApp({
+      onSessionIdChange,
+      initialSelectedWorkspaceCwd: '/workspace',
+    });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenCalledWith(
+      'session-1',
+      'secondary',
+      '/work/secondary',
+    );
+    expect(onSessionIdChange).not.toHaveBeenCalledWith(
+      'session-1',
+      undefined,
+      '/workspace',
+    );
+  });
+
+  it('notifies the host on each deferred workspace switch while no session is active', async () => {
+    // With no active session the report must re-run when the next-session
+    // workspace selection changes, so a routing host follows each switch
+    // rather than reacting to session-id changes alone.
+    mockConnection.sessionId = undefined;
+    mockConnection.workspaceCwd = '/work/secondary';
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+        {
+          id: 'tertiary',
+          cwd: '/work/tertiary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    };
+    const onSessionIdChange = vi.fn();
+
+    renderApp({ onSessionIdChange });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenLastCalledWith(
+      undefined,
+      undefined,
+      '/workspace',
+    );
+
+    act(() => {
+      testState.latestChatEditorProps?.onSelectWorkspace?.('/work/tertiary');
+    });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenLastCalledWith(
+      undefined,
+      'tertiary',
+      '/work/tertiary',
+    );
+  });
+
   it('creates scratch once, accepts refreshed capabilities, and opens a fresh chat', async () => {
     mockWorkspace.capabilities = {
       features: [
diff --git a/packages/web-shell/client/App.tsx b/packages/web-shell/client/App.tsx
index 70da8510a02..05b505f5c3b 100644
--- a/packages/web-shell/client/App.tsx
+++ b/packages/web-shell/client/App.tsx
@@ -4619,8 +4619,14 @@ export function App({
       lastNotifiedWorkspaceCwdRef.current = undefined;
       return;
     }
+    // After a session is cleared the connection's workspaceCwd is a leftover
+    // from the previous session; reporting it would misroute the host back to
+    // the old workspace. activeWorkspaceCwd resolves the workspace picked for
+    // the next session (locked / selected / primary) and is what the composer
+    // chip reports, so the host and the chip stay in agreement.
+    const reportedWorkspaceCwd = activeWorkspaceCwd ?? connection.workspaceCwd;
     const activeWorkspace = workspaces.find(
-      (entry) => entry.cwd === connection.workspaceCwd,
+      (entry) => entry.cwd === reportedWorkspaceCwd,
     );
     if (connection.sessionId && !workspace.capabilities) return;
     const workspaceId =
@@ -4630,23 +4636,24 @@ export function App({
     if (
       lastNotifiedSessionIdRef.current === connection.sessionId &&
       lastNotifiedWorkspaceIdRef.current === workspaceId &&
-      lastNotifiedWorkspaceCwdRef.current === connection.workspaceCwd
+      lastNotifiedWorkspaceCwdRef.current === reportedWorkspaceCwd
     ) {
       return;
     }
     lastNotifiedSessionIdRef.current = connection.sessionId;
     lastNotifiedWorkspaceIdRef.current = workspaceId;
-    lastNotifiedWorkspaceCwdRef.current = connection.workspaceCwd;
+    lastNotifiedWorkspaceCwdRef.current = reportedWorkspaceCwd;
     onSessionIdChange?.(
       connection.sessionId,
       workspaceId,
-      connection.workspaceCwd,
+      reportedWorkspaceCwd,
     );
   }, [
     connection.missingSession,
     connection.sessionId,
     connection.workspaceCwd,
     onSessionIdChange,
+    activeWorkspaceCwd,
     workspace.capabilities,
     workspaces,
   ]);