diff --git a/src/client.ts b/src/client.ts
index 5a061ec..5a8038b 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -70,6 +70,9 @@ export function createClient(config: CreateClientConfig): Base44Client {
     headers: optionalHeaders,
   } = config;
 
+  // Normalize appBaseUrl to always be a string (empty if not provided or invalid)
+  const normalizedAppBaseUrl = typeof appBaseUrl === "string" ? appBaseUrl : "";
+
   const socketConfig: RoomsSocketConfig = {
     serverUrl,
     mountPath: "/ws-user-apps/socket.io/",
@@ -135,7 +138,7 @@ export function createClient(config: CreateClientConfig): Base44Client {
     functionsAxiosClient,
     appId,
     {
-      appBaseUrl,
+      appBaseUrl: normalizedAppBaseUrl,
       serverUrl,
     }
   );
diff --git a/src/modules/auth.ts b/src/modules/auth.ts
index 50f0e0e..d186622 100644
--- a/src/modules/auth.ts
+++ b/src/modules/auth.ts
@@ -49,9 +49,7 @@ export function createAuthModule(
         : window.location.href;
 
       // Build the login URL
-      const loginUrl = `${
-        options.appBaseUrl ?? ""
-      }/login?from_url=${encodeURIComponent(redirectUrl)}`;
+      const loginUrl = `${options.appBaseUrl}/login?from_url=${encodeURIComponent(redirectUrl)}`;
 
       // Redirect to the login page
       window.location.href = loginUrl;
@@ -65,7 +63,7 @@ export function createAuthModule(
       // Build the provider login URL (google is the default, so no provider path needed)
       const providerPath = provider === "google" ? "" : `/${provider}`;
       const loginUrl = `${
-        options.serverUrl
+        options.appBaseUrl
       }/api/apps/auth${providerPath}/login?app_id=${appId}&from_url=${encodeURIComponent(
         redirectUrl
       )}`;
@@ -75,29 +73,29 @@ export function createAuthModule(
     },
 
     // Logout the current user
-    // Removes the token from localStorage and optionally redirects to a URL or reloads the page
     logout(redirectUrl?: string) {
-      // Remove token from axios headers
+      // Remove token from axios headers (always do this)
       delete axios.defaults.headers.common["Authorization"];
 
-      // Remove token from localStorage
-      if (typeof window !== "undefined" && window.localStorage) {
-        try {
-          window.localStorage.removeItem("base44_access_token");
-          // Remove "token" that is set by the built-in SDK of platform version 2
-          window.localStorage.removeItem("token");
-        } catch (e) {
-          console.error("Failed to remove token from localStorage:", e);
-        }
-      }
-
-      // Redirect if a URL is provided
+      // Only do the rest if in a browser environment
       if (typeof window !== "undefined") {
-        if (redirectUrl) {
-          window.location.href = redirectUrl;
-        } else {
-          window.location.reload();
+        // Remove token from localStorage
+        if (window.localStorage) {
+          try {
+            window.localStorage.removeItem("base44_access_token");
+            // Remove "token" that is set by the built-in SDK of platform version 2
+            window.localStorage.removeItem("token");
+          } catch (e) {
+            console.error("Failed to remove token from localStorage:", e);
+          }
         }
+
+        // Determine the from_url parameter
+        const fromUrl = redirectUrl || window.location.href;
+
+        // Redirect to server-side logout endpoint to clear HTTP-only cookies
+        const logoutUrl = `${options.appBaseUrl}/api/apps/auth/logout?from_url=${encodeURIComponent(fromUrl)}`;
+        window.location.href = logoutUrl;
       }
     },
 
diff --git a/src/modules/auth.types.ts b/src/modules/auth.types.ts
index 48d5101..52dedec 100644
--- a/src/modules/auth.types.ts
+++ b/src/modules/auth.types.ts
@@ -98,8 +98,8 @@ export interface ResetPasswordParams {
 export interface AuthModuleOptions {
   /** Server URL for API requests. */
   serverUrl: string;
-  /** Optional base URL for the app (used for login redirects). */
-  appBaseUrl?: string;
+  /** Base URL for the app (used for login redirects). */
+  appBaseUrl: string;
 }
 
 /**
diff --git a/tests/unit/auth.test.js b/tests/unit/auth.test.js
index 9ed354e..81aa9aa 100644
--- a/tests/unit/auth.test.js
+++ b/tests/unit/auth.test.js
@@ -7,17 +7,33 @@ describe('Auth Module', () => {
   let scope;
   const appId = 'test-app-id';
   const serverUrl = 'https://api.base44.com';
-  
+  const appBaseUrl = 'https://api.base44.com';
+
   beforeEach(() => {
+    // Mock window.addEventListener and document for analytics module
+    if (typeof window !== 'undefined') {
+      if (!window.addEventListener) {
+        window.addEventListener = vi.fn();
+        window.removeEventListener = vi.fn();
+      }
+    }
+    if (typeof document === 'undefined') {
+      global.document = {
+        referrer: '',
+        visibilityState: 'visible'
+      };
+    }
+
     // Create a new client for each test
     base44 = createClient({
       serverUrl,
       appId,
+      appBaseUrl,
     });
-    
+
     // Create a nock scope for mocking API calls
     scope = nock(serverUrl);
-    
+
     // Enable request debugging for Nock
     nock.disableNetConnect();
     nock.emitter.on('no match', (req) => {
@@ -143,15 +159,15 @@ describe('Auth Module', () => {
       global.window = {
         location: mockLocation
       };
-      
+
       const nextUrl = 'https://example.com/dashboard';
       base44.auth.redirectToLogin(nextUrl);
-      
+
       // Verify the redirect URL was set correctly
       expect(mockLocation.href).toBe(
-        `/login?from_url=${encodeURIComponent(nextUrl)}`
+        `${appBaseUrl}/login?from_url=${encodeURIComponent(nextUrl)}`
       );
-      
+
       // Restore window
       global.window = originalWindow;
     });
@@ -169,7 +185,7 @@ describe('Auth Module', () => {
 
       // Verify the redirect URL uses current URL
       expect(mockLocation.href).toBe(
-        `/login?from_url=${encodeURIComponent(currentUrl)}`
+        `${appBaseUrl}/login?from_url=${encodeURIComponent(currentUrl)}`
       );
 
       // Restore window
@@ -204,6 +220,12 @@ describe('Auth Module', () => {
     });
 
     test('should use relative URL for login redirect when appBaseUrl is not provided', () => {
+      // Create a client without appBaseUrl
+      const clientWithoutAppBaseUrl = createClient({
+        serverUrl,
+        appId,
+      });
+
       // Mock window.location
       const originalWindow = global.window;
       const mockLocation = { href: '', origin: 'https://current-app.com' };
@@ -212,7 +234,7 @@ describe('Auth Module', () => {
       };
 
       const nextUrl = 'https://example.com/dashboard';
-      base44.auth.redirectToLogin(nextUrl);
+      clientWithoutAppBaseUrl.auth.redirectToLogin(nextUrl);
 
       // Verify the redirect URL uses a relative path (no appBaseUrl prefix)
       expect(mockLocation.href).toBe(
@@ -316,33 +338,33 @@ describe('Auth Module', () => {
       global.window = {
         location: mockLocation
       };
-      
+
       const redirectUrl = 'https://example.com/logout-success';
       base44.auth.logout(redirectUrl);
-      
-      // Verify redirect
-      expect(mockLocation.href).toBe(redirectUrl);
-      
+
+      // Verify redirect to server-side logout endpoint with from_url parameter
+      const expectedUrl = `${appBaseUrl}/api/apps/auth/logout?from_url=${encodeURIComponent(redirectUrl)}`;
+      expect(mockLocation.href).toBe(expectedUrl);
+
       // Restore window
       global.window = originalWindow;
     });
     
-    test('should reload page when no redirect URL is provided', async () => {
-      // Mock window object with reload function
-      const mockReload = vi.fn();
+    test('should redirect to logout endpoint when no redirect URL is provided', async () => {
+      // Mock window object
+      const mockLocation = { href: 'https://example.com/current-page' };
       const originalWindow = global.window;
       global.window = {
-        location: {
-          reload: mockReload
-        }
+        location: mockLocation
       };
-      
+
       // Call logout without redirect URL
       base44.auth.logout();
-      
-      // Verify page reload was called
-      expect(mockReload).toHaveBeenCalledTimes(1);
-      
+
+      // Verify redirect to server-side logout endpoint with current page as from_url
+      const expectedUrl = `${appBaseUrl}/api/apps/auth/logout?from_url=${encodeURIComponent('https://example.com/current-page')}`;
+      expect(mockLocation.href).toBe(expectedUrl);
+
       // Restore window
       global.window = originalWindow;
     });
diff --git a/tests/unit/client.test.js b/tests/unit/client.test.js
index 74c97aa..4a7b3ef 100644
--- a/tests/unit/client.test.js
+++ b/tests/unit/client.test.js
@@ -64,7 +64,7 @@ describe('Client Creation', () => {
       serviceToken: 'service-token-123',
       requiresAuth: true,
     });
-    
+
     expect(client).toBeDefined();
     expect(client.entities).toBeDefined();
     expect(client.integrations).toBeDefined();
@@ -78,6 +78,59 @@ describe('Client Creation', () => {
 
 });
 
+describe('appBaseUrl Normalization', () => {
+  test('should use appBaseUrl when provided as a string', () => {
+    const customAppBaseUrl = 'https://custom-app.example.com';
+    const client = createClient({
+      appId: 'test-app-id',
+      appBaseUrl: customAppBaseUrl,
+    });
+
+    // Mock window.location
+    const originalWindow = global.window;
+    const mockLocation = { href: '', origin: 'https://current-app.com' };
+    global.window = {
+      location: mockLocation
+    };
+
+    const nextUrl = 'https://example.com/dashboard';
+    client.auth.redirectToLogin(nextUrl);
+
+    // Verify the redirect URL uses the custom appBaseUrl
+    expect(mockLocation.href).toBe(
+      `${customAppBaseUrl}/login?from_url=${encodeURIComponent(nextUrl)}`
+    );
+
+    // Restore window
+    global.window = originalWindow;
+  });
+
+  test('should normalize appBaseUrl to empty string when not provided', () => {
+    const client = createClient({
+      appId: 'test-app-id',
+      // appBaseUrl not provided
+    });
+
+    // Mock window.location
+    const originalWindow = global.window;
+    const mockLocation = { href: '', origin: 'https://current-app.com' };
+    global.window = {
+      location: mockLocation
+    };
+
+    const nextUrl = 'https://example.com/dashboard';
+    client.auth.redirectToLogin(nextUrl);
+
+    // Verify the redirect URL uses empty string (relative path)
+    expect(mockLocation.href).toBe(
+      `/login?from_url=${encodeURIComponent(nextUrl)}`
+    );
+
+    // Restore window
+    global.window = originalWindow;
+  });
+});
+
 describe('createClientFromRequest', () => {
   test('should create client from request with all headers', () => {
     const mockRequest = {