diff --git a/src/myfasthtml/auth/routes.py b/src/myfasthtml/auth/routes.py
index db92c18..38cf3e9 100644
--- a/src/myfasthtml/auth/routes.py
+++ b/src/myfasthtml/auth/routes.py
@@ -18,7 +18,7 @@ from ..auth.utils import (
 )
 
 
-def setup_auth_routes(app, rt, mount_auth_app=True, sqlite_db_path="Users.db"):
+def setup_auth_routes(app, rt, mount_auth_app=True, sqlite_db_path="Users.db", base_url=None):
   """
   Setup all authentication and protected routes.
 
@@ -27,6 +27,7 @@ def setup_auth_routes(app, rt, mount_auth_app=True, sqlite_db_path="Users.db"):
       rt: Route decorator from FastHTML
       mount_auth_app: Whether to mount the auth FastApi API routes
       sqlite_db_path: by default, create a new SQLite database at this path
+      base_url: Base URL for the application (default to localhost:5001 if not provided)
   """
   
   # ============================================================================
@@ -61,7 +62,7 @@ def setup_auth_routes(app, rt, mount_auth_app=True, sqlite_db_path="Users.db"):
         RedirectResponse on success, or LoginPage with error on failure
     """
     # Attempt login
-    auth_data = login_user(email, password)
+    auth_data = login_user(email, password, base_url=base_url)
     
     if auth_data:
       # Login successful - store tokens in session
diff --git a/src/myfasthtml/auth/utils.py b/src/myfasthtml/auth/utils.py
index dc7d369..5b4c892 100644
--- a/src/myfasthtml/auth/utils.py
+++ b/src/myfasthtml/auth/utils.py
@@ -163,13 +163,14 @@ def check_token_expiry(token: str) -> Optional[float]:
     return None
 
 
-def login_user(email: str, password: str) -> Optional[Dict[str, Any]]:
+def login_user(email: str, password: str, base_url: str = None) -> Optional[Dict[str, Any]]:
   """
   Authenticate user with email and password.
 
   Args:
       email: User email address
       password: User password
+      base_url:
 
   Returns:
       Dictionary containing access_token, refresh_token, and user_info if successful,
@@ -177,7 +178,7 @@ def login_user(email: str, password: str) -> Optional[Dict[str, Any]]:
   """
   try:
     response = http_client.post(
-      f"{API_BASE_URL}/auth/login",
+      f"{base_url or API_BASE_URL}/auth/login",
       data={"username": email, "password": password},
       headers={"Content-Type": "application/x-www-form-urlencoded"},
       timeout=10.0
@@ -196,7 +197,7 @@ def login_user(email: str, password: str) -> Optional[Dict[str, Any]]:
     return None
 
 
-def register_user(email: str, username: str, password: str) -> Optional[Dict[str, Any]]:
+def register_user(email: str, username: str, password: str, base_url: str = None) -> Optional[Dict[str, Any]]:
   """
   Register a new user.
 
@@ -204,14 +205,14 @@ def register_user(email: str, username: str, password: str) -> Optional[Dict[str
       email: User email address
       username: User name
       password: User password
-
+      base_url:
   Returns:
       Dictionary containing success message if registration succeeds,
       None if registration fails
   """
   try:
     response = http_client.post(
-      f"{API_BASE_URL}/auth/register",
+      f"{base_url or API_BASE_URL}/auth/register",
       json={"email": email, "username": username, "password": password},
       timeout=10.0
     )
@@ -224,20 +225,20 @@ def register_user(email: str, username: str, password: str) -> Optional[Dict[str
     return None
 
 
-def refresh_access_token(refresh_token: str) -> Optional[Dict[str, Any]]:
+def refresh_access_token(refresh_token: str, base_url: str = None) -> Optional[Dict[str, Any]]:
   """
   Refresh the access token using a refresh token.
 
   Args:
       refresh_token: Valid refresh token
-
+      base_url:
   Returns:
       Dictionary containing new access_token and refresh_token if successful,
       None if refresh fails
   """
   try:
     response = http_client.post(
-      f"{API_BASE_URL}/auth/refresh",
+      f"{base_url or API_BASE_URL}/auth/refresh",
       json={"refresh_token": refresh_token},
       timeout=10.0
     )
@@ -254,20 +255,20 @@ def refresh_access_token(refresh_token: str) -> Optional[Dict[str, Any]]:
     return None
 
 
-def get_user_info(access_token: str) -> Optional[Dict[str, Any]]:
+def get_user_info(access_token: str, base_url: str = None) -> Optional[Dict[str, Any]]:
   """
   Get current user information using access token.
 
   Args:
       access_token: Valid access token
-
+      base_url:
   Returns:
       Dictionary containing user information if successful,
       None if request fails
   """
   try:
     response = http_client.get(
-      f"{API_BASE_URL}/auth/me",
+      f"{base_url or API_BASE_URL}/auth/me",
       headers={"Authorization": f"Bearer {access_token}"},
       timeout=10.0
     )
@@ -280,19 +281,19 @@ def get_user_info(access_token: str) -> Optional[Dict[str, Any]]:
     return None
 
 
-def logout_user(refresh_token: str) -> bool:
+def logout_user(refresh_token: str, base_url: str = None) -> bool:
   """
   Logout user by revoking the refresh token.
 
   Args:
       refresh_token: Refresh token to revoke
-
+      base_url:
   Returns:
       True if logout successful, False otherwise
   """
   try:
     response = http_client.post(
-      f"{API_BASE_URL}/auth/logout",
+      f"{base_url or API_BASE_URL}/auth/logout",
       json={"refresh_token": refresh_token},
       timeout=10.0
     )