diff --git a/frontend/src/stores/uiStore.test.ts b/frontend/src/stores/uiStore.test.ts
new file mode 100644
index 00000000..c17b13b5
--- /dev/null
+++ b/frontend/src/stores/uiStore.test.ts
@@ -0,0 +1,373 @@
+import { describe, it, expect, beforeEach } from "vitest";
+import {
+  useUIStore,
+  selectActiveModal,
+  selectModalData,
+  selectSidebarOpen,
+  selectToasts,
+  selectGlobalLoading,
+  selectSelectedAsset,
+  selectIsMobileView,
+  selectInsightsTray,
+} from "./uiStore";
+
+function resetStoreState() {
+  const initialState = useUIStore.getInitialState();
+  useUIStore.setState(initialState, true);
+}
+
+describe("uiStore", () => {
+  beforeEach(() => {
+    resetStoreState();
+  });
+
+  it("initializes with default UI state", () => {
+    const state = useUIStore.getState();
+
+    expect(state.activeModal).toBeNull();
+    expect(state.modalData).toBeNull();
+    expect(state.sidebarOpen).toBe(true);
+    expect(state.sidebarView).toBe("default");
+    expect(state.toasts).toEqual([]);
+    expect(state.globalLoading).toBe(false);
+    expect(state.loadingMessage).toBeNull();
+    expect(state.selectedAsset).toBeNull();
+    expect(state.selectedBridge).toBeNull();
+    expect(state.selectedTimeRange).toBe("24h");
+    expect(state.isMobileView).toBe(false);
+    expect(state.isTouchDevice).toBe(false);
+    expect(state.insightsTrayOpen).toBe(false);
+  });
+
+  describe("modal actions", () => {
+    it("opens a modal and sets its data", () => {
+      useUIStore.getState().openModal("assetDetails", { assetId: "XLM" });
+
+      const state = useUIStore.getState();
+      expect(state.activeModal).toBe("assetDetails");
+      expect(state.modalData).toEqual({ assetId: "XLM" });
+    });
+
+    it("opens a modal without data", () => {
+      useUIStore.getState().openModal("settings");
+
+      const state = useUIStore.getState();
+      expect(state.activeModal).toBe("settings");
+      expect(state.modalData).toBeNull();
+    });
+
+    it("closes the active modal and clears data", () => {
+      useUIStore.getState().openModal("bridgeDetails", { bridgeId: "1" });
+      useUIStore.getState().closeModal();
+
+      const state = useUIStore.getState();
+      expect(state.activeModal).toBeNull();
+      expect(state.modalData).toBeNull();
+    });
+
+    it("merges modal data with setModalData", () => {
+      useUIStore.getState().openModal("alertSettings", { alertId: "alert-1" });
+      useUIStore.getState().setModalData({ threshold: "high" });
+
+      const state = useUIStore.getState();
+      expect(state.modalData).toEqual({ alertId: "alert-1", threshold: "high" });
+    });
+
+    it("handles closeModal when no modal is open", () => {
+      useUIStore.getState().closeModal();
+
+      const state = useUIStore.getState();
+      expect(state.activeModal).toBeNull();
+      expect(state.modalData).toBeNull();
+    });
+  });
+
+  describe("sidebar actions", () => {
+    it("toggles sidebar from open to closed", () => {
+      expect(useUIStore.getState().sidebarOpen).toBe(true);
+
+      useUIStore.getState().toggleSidebar();
+
+      expect(useUIStore.getState().sidebarOpen).toBe(false);
+    });
+
+    it("toggles sidebar from closed to open", () => {
+      useUIStore.getState().setSidebarOpen(false);
+
+      useUIStore.getState().toggleSidebar();
+
+      expect(useUIStore.getState().sidebarOpen).toBe(true);
+    });
+
+    it("sets sidebar open state explicitly", () => {
+      useUIStore.getState().setSidebarOpen(false);
+      expect(useUIStore.getState().sidebarOpen).toBe(false);
+
+      useUIStore.getState().setSidebarOpen(true);
+      expect(useUIStore.getState().sidebarOpen).toBe(true);
+    });
+
+    it("sets sidebar view", () => {
+      useUIStore.getState().setSidebarView("favorites");
+      expect(useUIStore.getState().sidebarView).toBe("favorites");
+
+      useUIStore.getState().setSidebarView("alerts");
+      expect(useUIStore.getState().sidebarView).toBe("alerts");
+
+      useUIStore.getState().setSidebarView("settings");
+      expect(useUIStore.getState().sidebarView).toBe("settings");
+    });
+
+    it("resets sidebar view to default", () => {
+      useUIStore.getState().setSidebarView("alerts");
+
+      useUIStore.getState().setSidebarView("default");
+
+      expect(useUIStore.getState().sidebarView).toBe("default");
+    });
+  });
+
+  describe("toast actions", () => {
+    it("adds a toast with auto-generated id", () => {
+      useUIStore.getState().addToast("Operation successful", "success");
+
+      const state = useUIStore.getState();
+      expect(state.toasts).toHaveLength(1);
+      expect(state.toasts[0].message).toBe("Operation successful");
+      expect(state.toasts[0].type).toBe("success");
+      expect(state.toasts[0].id).toMatch(/^toast-/);
+      expect(state.toasts[0].duration).toBe(5000);
+    });
+
+    it("adds a toast with custom duration", () => {
+      useUIStore.getState().addToast("Persistent toast", "info", 10000);
+
+      expect(useUIStore.getState().toasts[0].duration).toBe(10000);
+    });
+
+    it("adds multiple toasts", () => {
+      useUIStore.getState().addToast("First", "info");
+      useUIStore.getState().addToast("Second", "warning");
+
+      const { toasts } = useUIStore.getState();
+      expect(toasts).toHaveLength(2);
+      expect(toasts[0].message).toBe("First");
+      expect(toasts[1].message).toBe("Second");
+    });
+
+    it("removes a toast by id", () => {
+      useUIStore.getState().addToast("Removable", "error");
+      const id = useUIStore.getState().toasts[0].id;
+
+      useUIStore.getState().removeToast(id);
+
+      expect(useUIStore.getState().toasts).toHaveLength(0);
+    });
+
+    it("removing a non-existent toast does nothing", () => {
+      useUIStore.getState().addToast("Stay", "info");
+
+      useUIStore.getState().removeToast("non-existent-id");
+
+      expect(useUIStore.getState().toasts).toHaveLength(1);
+    });
+
+    it("clears all toasts", () => {
+      useUIStore.getState().addToast("One", "info");
+      useUIStore.getState().addToast("Two", "warning");
+
+      useUIStore.getState().clearToasts();
+
+      expect(useUIStore.getState().toasts).toEqual([]);
+    });
+  });
+
+  describe("loading actions", () => {
+    it("sets global loading with a message", () => {
+      useUIStore.getState().setGlobalLoading(true, "Fetching data...");
+
+      const state = useUIStore.getState();
+      expect(state.globalLoading).toBe(true);
+      expect(state.loadingMessage).toBe("Fetching data...");
+    });
+
+    it("sets global loading without a message", () => {
+      useUIStore.getState().setGlobalLoading(true);
+
+      const state = useUIStore.getState();
+      expect(state.globalLoading).toBe(true);
+      expect(state.loadingMessage).toBeNull();
+    });
+
+    it("clears global loading", () => {
+      useUIStore.getState().setGlobalLoading(true, "Loading");
+      useUIStore.getState().setGlobalLoading(false);
+
+      const state = useUIStore.getState();
+      expect(state.globalLoading).toBe(false);
+      expect(state.loadingMessage).toBeNull();
+    });
+  });
+
+  describe("selection actions", () => {
+    it("sets selected asset", () => {
+      useUIStore.getState().setSelectedAsset("XLM");
+      expect(useUIStore.getState().selectedAsset).toBe("XLM");
+    });
+
+    it("clears selected asset", () => {
+      useUIStore.getState().setSelectedAsset("XLM");
+      useUIStore.getState().setSelectedAsset(null);
+
+      expect(useUIStore.getState().selectedAsset).toBeNull();
+    });
+
+    it("sets selected bridge", () => {
+      useUIStore.getState().setSelectedBridge("bridge-1");
+      expect(useUIStore.getState().selectedBridge).toBe("bridge-1");
+    });
+
+    it("clears selected bridge", () => {
+      useUIStore.getState().setSelectedBridge("bridge-1");
+      useUIStore.getState().setSelectedBridge(null);
+
+      expect(useUIStore.getState().selectedBridge).toBeNull();
+    });
+
+    it("sets selected time range", () => {
+      useUIStore.getState().setSelectedTimeRange("7d");
+      expect(useUIStore.getState().selectedTimeRange).toBe("7d");
+
+      useUIStore.getState().setSelectedTimeRange("1h");
+      expect(useUIStore.getState().selectedTimeRange).toBe("1h");
+
+      useUIStore.getState().setSelectedTimeRange("30d");
+      expect(useUIStore.getState().selectedTimeRange).toBe("30d");
+    });
+  });
+
+  describe("insights tray actions", () => {
+    it("opens insights tray and sets the asset symbol", () => {
+      useUIStore.getState().openInsightsTray("XLM");
+
+      const state = useUIStore.getState();
+      expect(state.insightsTrayOpen).toBe(true);
+      expect(state.selectedAsset).toBe("XLM");
+    });
+
+    it("closes insights tray", () => {
+      useUIStore.getState().openInsightsTray("XLM");
+      useUIStore.getState().closeInsightsTray();
+
+      const state = useUIStore.getState();
+      expect(state.insightsTrayOpen).toBe(false);
+    });
+
+    it("closing insights tray does not clear the selected asset", () => {
+      useUIStore.getState().openInsightsTray("XLM");
+      useUIStore.getState().closeInsightsTray();
+
+      expect(useUIStore.getState().selectedAsset).toBe("XLM");
+    });
+  });
+
+  describe("view actions", () => {
+    it("sets mobile view", () => {
+      useUIStore.getState().setIsMobileView(true);
+      expect(useUIStore.getState().isMobileView).toBe(true);
+
+      useUIStore.getState().setIsMobileView(false);
+      expect(useUIStore.getState().isMobileView).toBe(false);
+    });
+
+    it("sets touch device", () => {
+      useUIStore.getState().setIsTouchDevice(true);
+      expect(useUIStore.getState().isTouchDevice).toBe(true);
+
+      useUIStore.getState().setIsTouchDevice(false);
+      expect(useUIStore.getState().isTouchDevice).toBe(false);
+    });
+  });
+
+  describe("resetUI", () => {
+    it("resets all UI state to initial values", () => {
+      const store = useUIStore.getState();
+      store.openModal("help", { page: "overview" });
+      store.toggleSidebar();
+      store.setSidebarView("settings");
+      store.addToast("Temp", "warning");
+      store.setGlobalLoading(true, "Working");
+      store.setSelectedAsset("XLM");
+      store.setSelectedBridge("bridge-2");
+      store.setSelectedTimeRange("7d");
+      store.openInsightsTray("USDC");
+      store.setIsMobileView(true);
+      store.setIsTouchDevice(true);
+
+      useUIStore.getState().resetUI();
+
+      const state = useUIStore.getState();
+      expect(state.activeModal).toBeNull();
+      expect(state.modalData).toBeNull();
+      expect(state.sidebarOpen).toBe(true);
+      expect(state.sidebarView).toBe("default");
+      expect(state.toasts).toEqual([]);
+      expect(state.globalLoading).toBe(false);
+      expect(state.loadingMessage).toBeNull();
+      expect(state.selectedAsset).toBeNull();
+      expect(state.selectedBridge).toBeNull();
+      expect(state.selectedTimeRange).toBe("24h");
+      expect(state.insightsTrayOpen).toBe(false);
+      expect(state.isMobileView).toBe(false);
+      expect(state.isTouchDevice).toBe(false);
+    });
+  });
+
+  describe("selectors", () => {
+    it("selectActiveModal returns the active modal", () => {
+      useUIStore.getState().openModal("settings");
+      expect(selectActiveModal(useUIStore.getState())).toBe("settings");
+    });
+
+    it("selectModalData returns the modal data", () => {
+      useUIStore.getState().openModal("assetDetails", { assetId: "XLM" });
+      expect(selectModalData(useUIStore.getState())).toEqual({ assetId: "XLM" });
+    });
+
+    it("selectSidebarOpen returns sidebar state", () => {
+      useUIStore.getState().setSidebarOpen(false);
+      expect(selectSidebarOpen(useUIStore.getState())).toBe(false);
+    });
+
+    it("selectToasts returns the toasts array", () => {
+      useUIStore.getState().addToast("Test", "info");
+      const toasts = selectToasts(useUIStore.getState());
+      expect(toasts).toHaveLength(1);
+    });
+
+    it("selectGlobalLoading returns loading state and message", () => {
+      useUIStore.getState().setGlobalLoading(true, "Working");
+      const result = selectGlobalLoading(useUIStore.getState());
+      expect(result).toEqual({ loading: true, message: "Working" });
+    });
+
+    it("selectSelectedAsset returns the selected asset", () => {
+      useUIStore.getState().setSelectedAsset("ETH");
+      expect(selectSelectedAsset(useUIStore.getState())).toBe("ETH");
+    });
+
+    it("selectIsMobileView returns mobile view state", () => {
+      useUIStore.getState().setIsMobileView(true);
+      expect(selectIsMobileView(useUIStore.getState())).toBe(true);
+    });
+
+    it("selectInsightsTray returns tray state and actions", () => {
+      useUIStore.getState().openInsightsTray("USDC");
+      const result = selectInsightsTray(useUIStore.getState());
+      expect(result.open).toBe(true);
+      expect(result.symbol).toBe("USDC");
+      expect(typeof result.openInsightsTray).toBe("function");
+      expect(typeof result.closeInsightsTray).toBe("function");
+    });
+  });
+});