diff --git a/oauth2client/tools.py b/oauth2client/tools.py
index 93b0171..839f296 100644
--- a/oauth2client/tools.py
+++ b/oauth2client/tools.py
@@ -24,7 +24,9 @@
 
 
 import BaseHTTPServer
-import gflags
+import argparse
+import logging
+import os
 import socket
 import sys
 import webbrowser
@@ -38,20 +40,31 @@
 except ImportError:
   from cgi import parse_qsl
 
+_CLIENT_SECRETS_MESSAGE = """WARNING: Please configure OAuth 2.0
 
-FLAGS = gflags.FLAGS
+To make this sample run you will need to populate the client_secrets.json file
+found at:
 
-gflags.DEFINE_boolean('auth_local_webserver', True,
-                      ('Run a local web server to handle redirects during '
-                       'OAuth authorization.'))
+   %s
 
-gflags.DEFINE_string('auth_host_name', 'localhost',
-                     ('Host name to use when running a local web server to '
-                      'handle redirects during OAuth authorization.'))
+with information from the APIs Console <https://code.google.com/apis/console>.
 
-gflags.DEFINE_multi_int('auth_host_port', [8080, 8090],
-                        ('Port to use when running a local web server to '
-                         'handle redirects during OAuth authorization.'))
+"""
+
+# run_parser is an ArgumentParser that contains command-line options expected
+# by tools.run(). Pass it in as part of the 'parents' argument to your own
+# ArgumentParser.
+argparser = argparse.ArgumentParser(add_help=False)
+argparser.add_argument('--auth_host_name', default='localhost',
+                        help='Hostname when running a local web server.')
+argparser.add_argument('--noauth_local_webserver', action='store_true',
+                        default=False, help='Do not run a local web server.')
+argparser.add_argument('--auth_host_port', default=[8080, 8090], type=int,
+                        nargs='*', help='Port web server should listen on.')
+argparser.add_argument('--logging_level', default='ERROR',
+                        choices=['DEBUG', 'INFO', 'WARNING', 'ERROR',
+                                 'CRITICAL'],
+                        help='Set the logging level of detail.')
 
 
 class ClientRedirectServer(BaseHTTPServer.HTTPServer):
@@ -92,8 +105,8 @@
     pass
 
 
-@util.positional(2)
-def run(flow, storage, http=None):
+@util.positional(3)
+def run(flow, storage, flags, http=None):
   """Core code for a command-line application.
 
   The run() function is called from your application and runs through all the
@@ -121,32 +134,40 @@
       during OAuth authorization.
       (default: 'true')
 
-  Since it uses flags make sure to initialize the gflags module before calling
-  run().
+  The tools module defines an ArgumentParser the already contains the flag
+  definitions that run() requires. You can pass that ArgumentParser to your
+  ArgumentParser constructor:
+
+    parser = argparse.ArgumentParser(description=__doc__,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        parents=[tools.run_parser])
+    flags = parser.parse_args(argv)
 
   Args:
     flow: Flow, an OAuth 2.0 Flow to step through.
     storage: Storage, a Storage to store the credential in.
+    flags: argparse.ArgumentParser, the command-line flags.
     http: An instance of httplib2.Http.request
          or something that acts like it.
 
   Returns:
     Credentials, the obtained credential.
   """
-  if FLAGS.auth_local_webserver:
+  logging.getLogger().setLevel(getattr(logging, flags.logging_level))
+  if not flags.noauth_local_webserver:
     success = False
     port_number = 0
-    for port in FLAGS.auth_host_port:
+    for port in flags.auth_host_port:
       port_number = port
       try:
-        httpd = ClientRedirectServer((FLAGS.auth_host_name, port),
+        httpd = ClientRedirectServer((flags.auth_host_name, port),
                                      ClientRedirectHandler)
       except socket.error, e:
         pass
       else:
         success = True
         break
-    FLAGS.auth_local_webserver = success
+    flags.noauth_local_webserver = not success
     if not success:
       print 'Failed to start a local webserver listening on either port 8080'
       print 'or port 9090. Please check your firewall settings and locally'
@@ -156,14 +177,14 @@
       print 'authorization.'
       print
 
-  if FLAGS.auth_local_webserver:
-    oauth_callback = 'http://%s:%s/' % (FLAGS.auth_host_name, port_number)
+  if not flags.noauth_local_webserver:
+    oauth_callback = 'http://%s:%s/' % (flags.auth_host_name, port_number)
   else:
     oauth_callback = OOB_CALLBACK_URN
   flow.redirect_uri = oauth_callback
   authorize_url = flow.step1_get_authorize_url()
 
-  if FLAGS.auth_local_webserver:
+  if not flags.noauth_local_webserver:
     webbrowser.open(authorize_url, new=1, autoraise=True)
     print 'Your browser has been opened to visit:'
     print
@@ -181,7 +202,7 @@
     print
 
   code = None
-  if FLAGS.auth_local_webserver:
+  if not flags.noauth_local_webserver:
     httpd.handle_request()
     if 'error' in httpd.query_params:
       sys.exit('Authentication request was rejected.')
@@ -203,3 +224,9 @@
   print 'Authentication successful.'
 
   return credential
+
+
+def message_if_missing(filename):
+  """Helpful message to display if the CLIENT_SECRETS file is missing."""
+
+  return _CLIENT_SECRETS_MESSAGE % filename