diff --git a/frontend/src/components/PluginsPanel.jsx b/frontend/src/components/PluginsPanel.jsx
index 90f80e2..22c72b2 100644
--- a/frontend/src/components/PluginsPanel.jsx
+++ b/frontend/src/components/PluginsPanel.jsx
@@ -72,7 +72,7 @@ export default function PluginsPanel({ sessionId, onClose }) {
     }
   });
 
-  // State for contextual menu and action toast feedback (#605)
+  // State for contextual menu and action toast feedback (#602, #605)
   const [activeMenuId, setActiveMenuId] = useState(null);
   const [notification, setNotification] = useState("");
 
@@ -188,7 +188,7 @@ export default function PluginsPanel({ sessionId, onClose }) {
     }
   }, [input, sessionId]);
 
-  // Close contextual action menu on global click or Escape key (#605)
+  // Close contextual action menu on global click or Escape key (#602, #605)
   useEffect(() => {
     const handleGlobalClick = () => setActiveMenuId(null);
     const handleKeyDown = (e) => {
@@ -395,7 +395,7 @@ export default function PluginsPanel({ sessionId, onClose }) {
             />
           </div>
 
-          {/* Plugin selector with favorite & pin toggles (#601), compatibility badges (#597), & contextual menus (#605) */}
+          {/* Plugin selector with favorite & pin toggles (#601), compatibility badges (#597), & contextual menus (#602, #605) */}
           <div data-testid="plugin-selector-list" className="flex flex-wrap gap-2 mb-4 md:mb-3 shrink-0 min-h-[32px]">
             {filteredPlugins.length > 0 ? (
               filteredPlugins.map((p) => {
@@ -426,7 +426,7 @@ export default function PluginsPanel({ sessionId, onClose }) {
                       {isPinned ? "★" : "☆"}
                     </button>
 
-                    {/* Context Menu Trigger Button */}
+                    {/* Context Menu Trigger Button (#602) */}
                     <button
                       type="button"
                       onClick={(e) => toggleContextMenu(e, p.id)}
@@ -436,7 +436,7 @@ export default function PluginsPanel({ sessionId, onClose }) {
                       ⋮
                     </button>
 
-                    {/* Context Dropdown Menu (#605) */}
+                    {/* Context Dropdown Menu (#602, #605) */}
                     {isMenuOpen && (
                       <div
                         onClick={(e) => e.stopPropagation()}
diff --git a/frontend/src/components/PluginsPanel.test.jsx b/frontend/src/components/PluginsPanel.test.jsx
index cecb3e5..94bc845 100644
--- a/frontend/src/components/PluginsPanel.test.jsx
+++ b/frontend/src/components/PluginsPanel.test.jsx
@@ -319,6 +319,44 @@ describe("PluginsPanel Export & Share Suite (#605)", () => {
   });
 });
 
+describe("PluginsPanel Favorite & Pin Support (#601)", () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.clearAllMocks();
+    api.getPlugins.mockResolvedValue({ plugins: mockPluginsList });
+    api.getPluginLogs.mockResolvedValue({ logs: [] });
+  });
+
+  afterEach(() => {
+    cleanup();
+  });
+
+  test("toggles pin state and saves to localStorage", async () => {
+    render(<PluginsPanel sessionId="session-601" onClose={vi.fn()} />);
+
+    await waitFor(() => {
+      expect(screen.getByText("Summarizer")).toBeInTheDocument();
+    });
+
+    const pinBtn = screen.getByLabelText("Pin Summarizer");
+    fireEvent.click(pinBtn);
+
+    expect(screen.getByLabelText("Unpin Summarizer")).toBeInTheDocument();
+    expect(JSON.parse(localStorage.getItem("plugins-panel-pinned:session-601"))).toContain("summarizer");
+  });
+
+  test("restores pinned favorites from localStorage on mount", async () => {
+    localStorage.setItem("plugins-panel-pinned:session-601", JSON.stringify(["summarizer"]));
+
+    render(<PluginsPanel sessionId="session-601" onClose={vi.fn()} />);
+
+    await waitFor(() => {
+      expect(screen.getByLabelText("Unpin Summarizer")).toBeInTheDocument();
+      expect(screen.getByLabelText("Pin Calculator")).toBeInTheDocument();
+    });
+  });
+});
+
 describe("PluginsPanel View State & Persistence Suite (#592)", () => {
   let store = {};