diff --git a/apiclient/discovery.py b/apiclient/discovery.py
index cf83530..16683e7 100644
--- a/apiclient/discovery.py
+++ b/apiclient/discovery.py
@@ -57,6 +57,7 @@
 from apiclient.schema import Schemas
 from email.mime.multipart import MIMEMultipart
 from email.mime.nonmultipart import MIMENonMultipart
+from oauth2client import util
 from oauth2client.anyjson import simplejson
 
 logger = logging.getLogger(__name__)
@@ -139,6 +140,7 @@
   return ''.join(result)
 
 
+@util.positional(2)
 def build(serviceName,
           version,
           http=None,
@@ -194,7 +196,7 @@
     raise UnknownApiNameOrVersion("name: %s  version: %s" % (serviceName,
                                                             version))
   if resp.status >= 400:
-    raise HttpError(resp, content, requested_url)
+    raise HttpError(resp, content, uri=requested_url)
 
   try:
     service = simplejson.loads(content)
@@ -202,10 +204,11 @@
     logger.error('Failed to parse as JSON: ' + content)
     raise InvalidJsonError()
 
-  return build_from_document(content, discoveryServiceUrl, http=http,
+  return build_from_document(content, base=discoveryServiceUrl, http=http,
       developerKey=developerKey, model=model, requestBuilder=requestBuilder)
 
 
+@util.positional(1)
 def build_from_document(
     service,
     base=None,
@@ -529,7 +532,8 @@
             raise UnknownFileType(media_filename)
           if not mimeparse.best_match([media_mime_type], ','.join(accept)):
             raise UnacceptableMimeTypeError(media_mime_type)
-          media_upload = MediaFileUpload(media_filename, media_mime_type)
+          media_upload = MediaFileUpload(media_filename,
+                                         mimetype=media_mime_type)
         elif isinstance(media_filename, MediaUpload):
           media_upload = media_filename
         else:
diff --git a/apiclient/errors.py b/apiclient/errors.py
index e744519..938d8d1 100644
--- a/apiclient/errors.py
+++ b/apiclient/errors.py
@@ -23,6 +23,7 @@
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
 
+from oauth2client import util
 from oauth2client.anyjson import simplejson
 
 
@@ -34,6 +35,7 @@
 class HttpError(Error):
   """HTTP data was invalid or unexpected."""
 
+  @util.positional(3)
   def __init__(self, resp, content, uri=None):
     self.resp = resp
     self.content = content
@@ -92,6 +94,7 @@
 class BatchError(HttpError):
   """Error occured during batch operations."""
 
+  @util.positional(2)
   def __init__(self, reason, resp=None, content=None):
     self.resp = resp
     self.content = content
@@ -106,6 +109,7 @@
 class UnexpectedMethodError(Error):
   """Exception raised by RequestMockBuilder on unexpected calls."""
 
+  @util.positional(1)
   def __init__(self, methodId=None):
     """Constructor for an UnexpectedMethodError."""
     super(UnexpectedMethodError, self).__init__(
diff --git a/apiclient/http.py b/apiclient/http.py
index 753dd09..4331cc2 100644
--- a/apiclient/http.py
+++ b/apiclient/http.py
@@ -43,6 +43,7 @@
 from errors import UnexpectedBodyError
 from errors import UnexpectedMethodError
 from model import JsonModel
+from oauth2client import util
 from oauth2client.anyjson import simplejson
 
 
@@ -162,6 +163,7 @@
     """
     raise NotImplementedError()
 
+  @util.positional(1)
   def _to_json(self, strip=None):
     """Utility function for creating a JSON representation of a MediaUpload.
 
@@ -226,6 +228,7 @@
         media_body=media).execute()
   """
 
+  @util.positional(2)
   def __init__(self, filename, mimetype=None, chunksize=DEFAULT_CHUNK_SIZE, resumable=False):
     """Constructor.
 
@@ -302,13 +305,13 @@
        string, a JSON representation of this instance, suitable to pass to
        from_json().
     """
-    return self._to_json(['_fd'])
+    return self._to_json(strip=['_fd'])
 
   @staticmethod
   def from_json(s):
     d = simplejson.loads(s)
-    return MediaFileUpload(
-        d['_filename'], d['_mimetype'], d['_chunksize'], d['_resumable'])
+    return MediaFileUpload(d['_filename'], mimetype=d['_mimetype'],
+                           chunksize=d['_chunksize'], resumable=d['_resumable'])
 
 
 class MediaIoBaseUpload(MediaUpload):
@@ -326,6 +329,7 @@
         media_body=media).execute()
   """
 
+  @util.positional(3)
   def __init__(self, fd, mimetype, chunksize=DEFAULT_CHUNK_SIZE,
       resumable=False):
     """Constructor.
@@ -414,6 +418,7 @@
   method.
   """
 
+  @util.positional(2)
   def __init__(self, body, mimetype='application/octet-stream',
                chunksize=DEFAULT_CHUNK_SIZE, resumable=False):
     """Create a new MediaBytesUpload.
@@ -496,8 +501,9 @@
   def from_json(s):
     d = simplejson.loads(s)
     return MediaInMemoryUpload(base64.b64decode(d['_b64body']),
-                               d['_mimetype'], d['_chunksize'],
-                               d['_resumable'])
+                               mimetype=d['_mimetype'],
+                               chunksize=d['_chunksize'],
+                               resumable=d['_resumable'])
 
 
 class MediaIoBaseDownload(object):
@@ -520,6 +526,7 @@
     print "Download Complete!"
   """
 
+  @util.positional(3)
   def __init__(self, fd, request, chunksize=DEFAULT_CHUNK_SIZE):
     """Constructor.
 
@@ -574,12 +581,13 @@
         self._done = True
       return MediaDownloadProgress(self._progress, self._total_size), self._done
     else:
-      raise HttpError(resp, content, self._uri)
+      raise HttpError(resp, content, uri=self._uri)
 
 
 class HttpRequest(object):
   """Encapsulates a single HTTP request."""
 
+  @util.positional(4)
   def __init__(self, http, postproc, uri,
                method='GET',
                body=None,
@@ -623,6 +631,7 @@
     # The bytes that have been uploaded.
     self.resumable_progress = 0
 
+  @util.positional(1)
   def execute(self, http=None):
     """Execute the request.
 
@@ -643,7 +652,7 @@
     if self.resumable:
       body = None
       while body is None:
-        _, body = self.next_chunk(http)
+        _, body = self.next_chunk(http=http)
       return body
     else:
       if 'content-length' not in self.headers:
@@ -661,13 +670,14 @@
         self.body = parsed.query
         self.headers['content-length'] = str(len(self.body))
 
-      resp, content = http.request(self.uri, self.method,
+      resp, content = http.request(self.uri, method=self.method,
                                    body=self.body,
                                    headers=self.headers)
       if resp.status >= 300:
-        raise HttpError(resp, content, self.uri)
+        raise HttpError(resp, content, uri=self.uri)
     return self.postproc(resp, content)
 
+  @util.positional(1)
   def next_chunk(self, http=None):
     """Execute the next step of a resumable upload.
 
@@ -782,7 +792,7 @@
         self.resumable_uri = resp['location']
     else:
       self._in_error_state = True
-      raise HttpError(resp, content, self.uri)
+      raise HttpError(resp, content, uri=self.uri)
 
     return (MediaUploadProgress(self.resumable_progress, self.resumable.size()),
             None)
@@ -844,9 +854,10 @@
 
     batch.add(service.animals().list(), list_animals)
     batch.add(service.farmers().list(), list_farmers)
-    batch.execute(http)
+    batch.execute(http=http)
   """
 
+  @util.positional(1)
   def __init__(self, callback=None, batch_uri=None):
     """Constructor for a BatchHttpRequest.
 
@@ -1042,6 +1053,7 @@
       self._last_auto_id += 1
     return str(self._last_auto_id)
 
+  @util.positional(2)
   def add(self, request, callback=None, request_id=None):
     """Add a new request.
 
@@ -1119,7 +1131,7 @@
                                  headers=headers)
 
     if resp.status >= 300:
-      raise HttpError(resp, content, self._batch_uri)
+      raise HttpError(resp, content, uri=self._batch_uri)
 
     # Now break out the individual responses and store each one.
     boundary, _ = content.split(None, 1)
@@ -1133,14 +1145,15 @@
     mime_response = parser.close()
 
     if not mime_response.is_multipart():
-      raise BatchError("Response not in multipart/mixed format.", resp,
-          content)
+      raise BatchError("Response not in multipart/mixed format.", resp=resp,
+                       content=content)
 
     for part in mime_response.get_payload():
       request_id = self._header_to_id(part['Content-ID'])
       response, content = self._deserialize_response(part.get_payload())
       self._responses[request_id] = (response, content)
 
+  @util.positional(1)
   def execute(self, http=None):
     """Execute all the requests as a single batched HTTP request.
 
@@ -1200,7 +1213,7 @@
       exception = None
       try:
         if resp.status >= 300:
-          raise HttpError(resp, content, request.uri)
+          raise HttpError(resp, content, uri=request.uri)
         response = request.postproc(resp, content)
       except HttpError, e:
         exception = e
@@ -1310,7 +1323,7 @@
           raise UnexpectedBodyError(expected_body, body)
       return HttpRequestMock(resp, content, postproc)
     elif self.check_unexpected:
-      raise UnexpectedMethodError(methodId)
+      raise UnexpectedMethodError(methodId=methodId)
     else:
       model = JsonModel(False)
       return HttpRequestMock(None, '{}', model.response)
diff --git a/apiclient/schema.py b/apiclient/schema.py
index cfed7de..d076a86 100644
--- a/apiclient/schema.py
+++ b/apiclient/schema.py
@@ -62,6 +62,8 @@
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
 import copy
+
+from oauth2client import util
 from oauth2client.anyjson import simplejson
 
 
@@ -80,6 +82,7 @@
     # Cache of pretty printed schemas.
     self.pretty = {}
 
+  @util.positional(2)
   def _prettyPrintByName(self, name, seen=None, dent=0):
     """Get pretty printed object prototype from the schema name.
 
@@ -102,7 +105,7 @@
 
     if name not in self.pretty:
       self.pretty[name] = _SchemaToStruct(self.schemas[name],
-          seen, dent).to_str(self._prettyPrintByName)
+          seen, dent=dent).to_str(self._prettyPrintByName)
 
     seen.pop()
 
@@ -121,6 +124,7 @@
     # Return with trailing comma and newline removed.
     return self._prettyPrintByName(name, seen=[], dent=1)[:-2]
 
+  @util.positional(2)
   def _prettyPrintSchema(self, schema, seen=None, dent=0):
     """Get pretty printed object prototype of schema.
 
@@ -136,7 +140,7 @@
     if seen is None:
       seen = []
 
-    return _SchemaToStruct(schema, seen, dent).to_str(self._prettyPrintByName)
+    return _SchemaToStruct(schema, seen, dent=dent).to_str(self._prettyPrintByName)
 
   def prettyPrintSchema(self, schema):
     """Get pretty printed object prototype of schema.
@@ -163,6 +167,7 @@
 class _SchemaToStruct(object):
   """Convert schema to a prototype object."""
 
+  @util.positional(3)
   def __init__(self, schema, seen, dent=0):
     """Constructor.
 
@@ -256,7 +261,7 @@
     elif '$ref' in schema:
       schemaName = schema['$ref']
       description = schema.get('description', '')
-      s = self.from_cache(schemaName, self.seen)
+      s = self.from_cache(schemaName, seen=self.seen)
       parts = s.splitlines()
       self.emitEnd(parts[0], description)
       for line in parts[1:]:
diff --git a/oauth2client/appengine.py b/oauth2client/appengine.py
index 12ba04d..6f63831 100644
--- a/oauth2client/appengine.py
+++ b/oauth2client/appengine.py
@@ -27,21 +27,20 @@
 
 import clientsecrets
 
-from anyjson import simplejson
-from client import AccessTokenRefreshError
-from client import AssertionCredentials
-from client import Credentials
-from client import Flow
-from client import OAuth2WebServerFlow
-from client import Storage
-from google.appengine.api import memcache
-from google.appengine.api import users
 from google.appengine.api import app_identity
+from google.appengine.api import users
 from google.appengine.ext import db
 from google.appengine.ext import webapp
 from google.appengine.ext.webapp.util import login_required
 from google.appengine.ext.webapp.util import run_wsgi_app
-
+from oauth2client import util
+from oauth2client.anyjson import simplejson
+from oauth2client.client import AccessTokenRefreshError
+from oauth2client.client import AssertionCredentials
+from oauth2client.client import Credentials
+from oauth2client.client import Flow
+from oauth2client.client import OAuth2WebServerFlow
+from oauth2client.client import Storage
 
 logger = logging.getLogger(__name__)
 
@@ -66,6 +65,7 @@
   generate and refresh its own access tokens.
   """
 
+  @util.positional(2)
   def __init__(self, scope, **kwargs):
     """Constructor for AppAssertionCredentials
 
@@ -77,9 +77,8 @@
     self.scope = scope
 
     super(AppAssertionCredentials, self).__init__(
-        None,
-        None,
-        None)
+        'ignored' # assertion_type is ignore in this subclass.
+        )
 
   @classmethod
   def from_json(cls, json):
@@ -195,6 +194,7 @@
   are stored by key_name.
   """
 
+  @util.positional(4)
   def __init__(self, model, key_name, property_name, cache=None):
     """Constructor for Storage.
 
@@ -286,11 +286,14 @@
 
   """
 
+  @util.positional(4)
   def __init__(self, client_id, client_secret, scope,
                auth_uri='https://accounts.google.com/o/oauth2/auth',
                token_uri='https://accounts.google.com/o/oauth2/token',
                user_agent=None,
-               message=None, **kwargs):
+               message=None,
+               callback_path='/oauth2callback',
+               **kwargs):
 
     """Constructor for OAuth2Decorator
 
@@ -307,15 +310,24 @@
       message: Message to display if there are problems with the OAuth 2.0
         configuration. The message may contain HTML and will be presented on the
         web interface for any method that uses the decorator.
+      callback_path: string, The absolute path to use as the callback URI. Note
+        that this must match up with the URI given when registering the
+        application in the APIs Console.
       **kwargs: dict, Keyword arguments are be passed along as kwargs to the
         OAuth2WebServerFlow constructor.
     """
-    self.flow = OAuth2WebServerFlow(client_id, client_secret, scope, user_agent,
-        auth_uri, token_uri, **kwargs)
+    self.flow = None
     self.credentials = None
-    self._request_handler = None
+    self._client_id = client_id
+    self._client_secret = client_secret
+    self._scope = scope
+    self._auth_uri = auth_uri
+    self._token_uri = token_uri
+    self._user_agent = user_agent
+    self._kwargs = kwargs
     self._message = message
     self._in_error = False
+    self._callback_path = callback_path
 
   def _display_error_message(self, request_handler):
     request_handler.response.out.write('<html><body>')
@@ -344,9 +356,11 @@
         request_handler.redirect(users.create_login_url(
             request_handler.request.uri))
         return
+
+      self._create_flow(request_handler)
+
       # Store the request URI in 'state' so we can use it later
       self.flow.params['state'] = request_handler.request.url
-      self._request_handler = request_handler
       self.credentials = StorageByKeyName(
           CredentialsModel, user.user_id(), 'credentials').get()
 
@@ -359,6 +373,26 @@
 
     return check_oauth
 
+  def _create_flow(self, request_handler):
+    """Create the Flow object.
+
+    The Flow is calculated lazily since we don't know where this app is
+    running until it receives a request, at which point redirect_uri can be
+    calculated and then the Flow object can be constructed.
+
+    Args:
+      request_handler: webapp.RequestHandler, the request handler.
+    """
+    if self.flow is None:
+      redirect_uri = request_handler.request.relative_url(
+          self._callback_path) # Usually /oauth2callback
+      self.flow = OAuth2WebServerFlow(self._client_id, self._client_secret,
+                                      self._scope, redirect_uri=redirect_uri,
+                                      user_agent=self._user_agent,
+                                      auth_uri=self._auth_uri,
+                                      token_uri=self._token_uri, **self._kwargs)
+
+
   def oauth_aware(self, method):
     """Decorator that sets up for OAuth 2.0 dance, but doesn't do it.
 
@@ -385,9 +419,9 @@
             request_handler.request.uri))
         return
 
+      self._create_flow(request_handler)
 
       self.flow.params['state'] = request_handler.request.url
-      self._request_handler = request_handler
       self.credentials = StorageByKeyName(
           CredentialsModel, user.user_id(), 'credentials').get()
       method(request_handler, *args, **kwargs)
@@ -407,11 +441,7 @@
     Must only be called from with a webapp.RequestHandler subclassed method
     that had been decorated with either @oauth_required or @oauth_aware.
     """
-    callback = self._request_handler.request.relative_url('/oauth2callback')
-    url = self.flow.step1_get_authorize_url(callback)
-    user = users.get_current_user()
-    memcache.set(user.user_id(), pickle.dumps(self.flow),
-                 namespace=OAUTH2CLIENT_NAMESPACE)
+    url = self.flow.step1_get_authorize_url()
     return str(url)
 
   def http(self):
@@ -423,6 +453,70 @@
     """
     return self.credentials.authorize(httplib2.Http())
 
+  @property
+  def callback_path(self):
+    """The absolute path where the callback will occur.
+
+    Note this is the absolute path, not the absolute URI, that will be
+    calculated by the decorator at runtime. See callback_handler() for how this
+    should be used.
+
+    Returns:
+      The callback path as a string.
+    """
+    return self._callback_path
+
+
+  def callback_handler(self):
+    """RequestHandler for the OAuth 2.0 redirect callback.
+
+    Usage:
+       app = webapp.WSGIApplication([
+         ('/index', MyIndexHandler),
+         ...,
+         (decorator.callback_path, decorator.callback_handler())
+       ])
+
+    Returns:
+      A webapp.RequestHandler that handles the redirect back from the
+      server during the OAuth 2.0 dance.
+    """
+    decorator = self
+
+    class OAuth2Handler(webapp.RequestHandler):
+      """Handler for the redirect_uri of the OAuth 2.0 dance."""
+
+      @login_required
+      def get(self):
+        error = self.request.get('error')
+        if error:
+          errormsg = self.request.get('error_description', error)
+          self.response.out.write(
+              'The authorization request failed: %s' % errormsg)
+        else:
+          user = users.get_current_user()
+          decorator._create_flow(self)
+          credentials = decorator.flow.step2_exchange(self.request.params)
+          StorageByKeyName(
+              CredentialsModel, user.user_id(), 'credentials').put(credentials)
+          self.redirect(str(self.request.get('state')))
+
+    return OAuth2Handler
+
+  def callback_application(self):
+    """WSGI application for handling the OAuth 2.0 redirect callback.
+
+    If you need finer grained control use `callback_handler` which returns just
+    the webapp.RequestHandler.
+
+    Returns:
+      A webapp.WSGIApplication that handles the redirect back from the
+      server during the OAuth 2.0 dance.
+    """
+    return webapp.WSGIApplication([
+        (self.callback_path, self.callback_handler())
+        ])
+
 
 class OAuth2DecoratorFromClientSecrets(OAuth2Decorator):
   """An OAuth2Decorator that builds from a clientsecrets file.
@@ -446,6 +540,7 @@
         # in API calls
   """
 
+  @util.positional(3)
   def __init__(self, filename, scope, message=None, cache=None):
     """Constructor
 
@@ -457,7 +552,7 @@
         clientsecrets file is missing or invalid. The message may contain HTML and
         will be presented on the web interface for any method that uses the
         decorator.
-      cache: An optional cache service client that implements get() and set() 
+      cache: An optional cache service client that implements get() and set()
         methods. See clientsecrets.loadfile() for details.
     """
     try:
@@ -469,9 +564,9 @@
                 client_info['client_id'],
                 client_info['client_secret'],
                 scope,
-                client_info['auth_uri'],
-                client_info['token_uri'],
-                message)
+                auth_uri=client_info['auth_uri'],
+                token_uri=client_info['token_uri'],
+                message=message)
     except clientsecrets.InvalidClientSecretsError:
       self._in_error = True
     if message is not None:
@@ -480,7 +575,8 @@
       self._message = "Please configure your application for OAuth 2.0"
 
 
-def oauth2decorator_from_clientsecrets(filename, scope, 
+@util.positional(2)
+def oauth2decorator_from_clientsecrets(filename, scope,
                                        message=None, cache=None):
   """Creates an OAuth2Decorator populated from a clientsecrets file.
 
@@ -492,46 +588,11 @@
       clientsecrets file is missing or invalid. The message may contain HTML and
       will be presented on the web interface for any method that uses the
       decorator.
-    cache: An optional cache service client that implements get() and set() 
+    cache: An optional cache service client that implements get() and set()
       methods. See clientsecrets.loadfile() for details.
 
   Returns: An OAuth2Decorator
 
   """
-  return OAuth2DecoratorFromClientSecrets(filename, scope, 
+  return OAuth2DecoratorFromClientSecrets(filename, scope,
     message=message, cache=cache)
-
-
-class OAuth2Handler(webapp.RequestHandler):
-  """Handler for the redirect_uri of the OAuth 2.0 dance."""
-
-  @login_required
-  def get(self):
-    error = self.request.get('error')
-    if error:
-      errormsg = self.request.get('error_description', error)
-      self.response.out.write(
-          'The authorization request failed: %s' % errormsg)
-    else:
-      user = users.get_current_user()
-      flow = pickle.loads(memcache.get(user.user_id(),
-                                       namespace=OAUTH2CLIENT_NAMESPACE))
-      # This code should be ammended with application specific error
-      # handling. The following cases should be considered:
-      # 1. What if the flow doesn't exist in memcache? Or is corrupt?
-      # 2. What if the step2_exchange fails?
-      if flow:
-        credentials = flow.step2_exchange(self.request.params)
-        StorageByKeyName(
-            CredentialsModel, user.user_id(), 'credentials').put(credentials)
-        self.redirect(str(self.request.get('state')))
-      else:
-        # TODO Add error handling here.
-        pass
-
-
-application = webapp.WSGIApplication([('/oauth2callback', OAuth2Handler)])
-
-
-def main():
-  run_wsgi_app(application)
diff --git a/oauth2client/client.py b/oauth2client/client.py
index 4e7ffcb..6b1bdbd 100644
--- a/oauth2client/client.py
+++ b/oauth2client/client.py
@@ -31,7 +31,8 @@
 import urllib
 import urlparse
 
-from anyjson import simplejson
+from oauth2client import util
+from oauth2client.anyjson import simplejson
 
 HAS_OPENSSL = False
 try:
@@ -327,6 +328,7 @@
   OAuth2Credentials objects may be safely pickled and unpickled.
   """
 
+  @util.positional(8)
   def __init__(self, access_token, client_id, client_secret, refresh_token,
                token_expiry, token_uri, user_agent, id_token=None):
     """Create an instance of OAuth2Credentials.
@@ -394,6 +396,7 @@
     request_orig = http.request
 
     # The closure that will replace 'httplib2.Http.request'.
+    @util.positional(1)
     def new_request(uri, method='GET', body=None, headers=None,
                     redirections=httplib2.DEFAULT_MAX_REDIRECTS,
                     connection_type=None):
@@ -481,7 +484,7 @@
         data['token_expiry'],
         data['token_uri'],
         data['user_agent'],
-        data.get('id_token', None))
+        id_token=data.get('id_token', None))
     retval.invalid = data['invalid']
     return retval
 
@@ -699,7 +702,8 @@
   AssertionCredentials objects may be safely pickled and unpickled.
   """
 
-  def __init__(self, assertion_type, user_agent,
+  @util.positional(2)
+  def __init__(self, assertion_type, user_agent=None,
                token_uri='https://accounts.google.com/o/oauth2/token',
                **unused_kwargs):
     """Constructor for AssertionFlowCredentials.
@@ -757,6 +761,7 @@
 
     MAX_TOKEN_LIFETIME_SECS = 3600 # 1 hour in seconds
 
+    @util.positional(4)
     def __init__(self,
         service_account_name,
         private_key,
@@ -781,7 +786,7 @@
 
       super(SignedJwtAssertionCredentials, self).__init__(
           'http://oauth.net/grant_type/jwt/1.0/bearer',
-          user_agent,
+          user_agent=user_agent,
           token_uri=token_uri,
           )
 
@@ -833,6 +838,7 @@
   # for the certs.
   _cached_http = httplib2.Http(MemoryCache())
 
+  @util.positional(2)
   def verify_id_token(id_token, audience, http=None,
       cert_uri=ID_TOKEN_VERIFICATON_CERTS):
     """Verifies a signed JWT id_token.
@@ -892,6 +898,7 @@
 
   return simplejson.loads(_urlsafe_b64decode(segments[1]))
 
+
 def _parse_exchange_token_response(content):
   """Parses response of an exchange token request.
 
@@ -919,10 +926,11 @@
 
   return resp
 
+
+@util.positional(4)
 def credentials_from_code(client_id, client_secret, scope, code,
-                        redirect_uri = 'postmessage',
-                        http=None, user_agent=None,
-                        token_uri='https://accounts.google.com/o/oauth2/token'):
+    redirect_uri='postmessage', http=None, user_agent=None,
+    token_uri='https://accounts.google.com/o/oauth2/token'):
   """Exchanges an authorization code for an OAuth2Credentials object.
 
   Args:
@@ -943,19 +951,19 @@
     FlowExchangeError if the authorization code cannot be exchanged for an
      access token
   """
-  flow = OAuth2WebServerFlow(client_id, client_secret, scope, user_agent,
-                             'https://accounts.google.com/o/oauth2/auth',
-                             token_uri)
+  flow = OAuth2WebServerFlow(client_id, client_secret, scope,
+                             redirect_uri=redirect_uri, user_agent=user_agent,
+                             auth_uri='https://accounts.google.com/o/oauth2/auth',
+                             token_uri=token_uri)
 
-  # We primarily make this call to set up the redirect_uri in the flow object
-  uriThatWeDontReallyUse = flow.step1_get_authorize_url(redirect_uri)
-  credentials = flow.step2_exchange(code, http)
+  credentials = flow.step2_exchange(code, http=http)
   return credentials
 
 
+@util.positional(3)
 def credentials_from_clientsecrets_and_code(filename, scope, code,
                                             message = None,
-                                            redirect_uri = 'postmessage',
+                                            redirect_uri='postmessage',
                                             http=None,
                                             cache=None):
   """Returns OAuth2Credentials from a clientsecrets file and an auth code.
@@ -966,7 +974,7 @@
   Args:
     filename: string, File name of clientsecrets.
     scope: string or list of strings, scope(s) to request.
-    code: string, An authroization code, most likely passed down from
+    code: string, An authorization code, most likely passed down from
       the client
     message: string, A friendly string to display to the user if the
       clientsecrets file is missing or invalid. If message is provided then
@@ -975,7 +983,7 @@
     redirect_uri: string, this is generally set to 'postmessage' to match the
       redirect_uri that the client specified
     http: httplib2.Http, optional http instance to use to do the fetch
-    cache: An optional cache service client that implements get() and set() 
+    cache: An optional cache service client that implements get() and set()
       methods. See clientsecrets.loadfile() for details.
 
   Returns:
@@ -988,20 +996,22 @@
     clientsecrets.InvalidClientSecretsError if the clientsecrets file is
       invalid.
   """
-  flow = flow_from_clientsecrets(filename, scope, message=message, cache=cache)
-  # We primarily make this call to set up the redirect_uri in the flow object
-  uriThatWeDontReallyUse = flow.step1_get_authorize_url(redirect_uri)
-  credentials = flow.step2_exchange(code, http)
+  flow = flow_from_clientsecrets(filename, scope, message=message, cache=cache,
+                                 redirect_uri=redirect_uri)
+  credentials = flow.step2_exchange(code, http=http)
   return credentials
 
 
 class OAuth2WebServerFlow(Flow):
   """Does the Web Server Flow for OAuth 2.0.
 
-  OAuth2Credentials objects may be safely pickled and unpickled.
+  OAuth2WebServerFlow objects may be safely pickled and unpickled.
   """
 
-  def __init__(self, client_id, client_secret, scope, user_agent=None,
+  @util.positional(4)
+  def __init__(self, client_id, client_secret, scope,
+               redirect_uri=None,
+               user_agent=None,
                auth_uri='https://accounts.google.com/o/oauth2/auth',
                token_uri='https://accounts.google.com/o/oauth2/token',
                **kwargs):
@@ -1012,6 +1022,9 @@
       client_secret: string client secret.
       scope: string or list of strings, scope(s) of the credentials being
         requested.
+      redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for
+          a non-web-based application, or a URI that handles the callback from
+          the authorization server.
       user_agent: string, HTTP User-Agent to provide for this application.
       auth_uri: string, URI for authorization endpoint. For convenience
         defaults to Google's endpoints but any OAuth 2.0 provider can be used.
@@ -1025,6 +1038,7 @@
     if type(scope) is list:
       scope = ' '.join(scope)
     self.scope = scope
+    self.redirect_uri = redirect_uri
     self.user_agent = user_agent
     self.auth_uri = auth_uri
     self.token_uri = token_uri
@@ -1032,27 +1046,33 @@
         'access_type': 'offline',
         }
     self.params.update(kwargs)
-    self.redirect_uri = None
 
-  def step1_get_authorize_url(self, redirect_uri=OOB_CALLBACK_URN):
+  @util.positional(1)
+  def step1_get_authorize_url(self, redirect_uri=None):
     """Returns a URI to redirect to the provider.
 
     Args:
       redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for
           a non-web-based application, or a URI that handles the callback from
-          the authorization server.
+          the authorization server. This parameter is deprecated, please move to
+          passing the redirect_uri in via the constructor.
 
-    If redirect_uri is 'urn:ietf:wg:oauth:2.0:oob' then pass in the
-    generated verification code to step2_exchange,
-    otherwise pass in the query parameters received
-    at the callback uri to step2_exchange.
+    Returns:
+      A URI as a string to redirect the user to begin the authorization flow.
     """
+    if redirect_uri is not None:
+      logger.warning(('The redirect_uri parameter for'
+          'OAuth2WebServerFlow.step1_get_authorize_url is deprecated. Please'
+          'move to passing the redirect_uri in via the constructor.'))
+      self.redirect_uri = redirect_uri
 
-    self.redirect_uri = redirect_uri
+    if self.redirect_uri is None:
+      raise ValueError('The value of redirect_uri must not be None.')
+
     query = {
         'response_type': 'code',
         'client_id': self.client_id,
-        'redirect_uri': redirect_uri,
+        'redirect_uri': self.redirect_uri,
         'scope': self.scope,
         }
     query.update(self.params)
@@ -1061,6 +1081,7 @@
     parts[4] = urllib.urlencode(query)
     return urlparse.urlunparse(parts)
 
+  @util.positional(2)
   def step2_exchange(self, code, http=None):
     """Exhanges a code for OAuth2Credentials.
 
@@ -1134,7 +1155,9 @@
         error_msg = 'Invalid response: %s.' % str(resp.status)
       raise FlowExchangeError(error_msg)
 
-def flow_from_clientsecrets(filename, scope, message=None, cache=None):
+
+@util.positional(2)
+def flow_from_clientsecrets(filename, scope, redirect_uri=None, message=None, cache=None):
   """Create a Flow from a clientsecrets file.
 
   Will create the right kind of Flow based on the contents of the clientsecrets
@@ -1143,11 +1166,14 @@
   Args:
     filename: string, File name of client secrets.
     scope: string or list of strings, scope(s) to request.
+    redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for
+        a non-web-based application, or a URI that handles the callback from
+        the authorization server.
     message: string, A friendly string to display to the user if the
       clientsecrets file is missing or invalid. If message is provided then
       sys.exit will be called in the case of an error. If message in not
       provided then clientsecrets.InvalidClientSecretsError will be raised.
-    cache: An optional cache service client that implements get() and set() 
+    cache: An optional cache service client that implements get() and set()
       methods. See clientsecrets.loadfile() for details.
 
   Returns:
@@ -1165,9 +1191,11 @@
             client_info['client_id'],
             client_info['client_secret'],
             scope,
-            None, # user_agent
-            client_info['auth_uri'],
-            client_info['token_uri'])
+            redirect_uri=redirect_uri,
+            user_agent=None,
+            auth_uri=client_info['auth_uri'],
+            token_uri=client_info['token_uri'])
+
   except clientsecrets.InvalidClientSecretsError:
     if message:
       sys.exit(message)
diff --git a/oauth2client/locked_file.py b/oauth2client/locked_file.py
index 8a7aff5..8f35c90 100644
--- a/oauth2client/locked_file.py
+++ b/oauth2client/locked_file.py
@@ -23,6 +23,8 @@
 import os
 import time
 
+from oauth2client import util
+
 logger = logging.getLogger(__name__)
 
 
@@ -292,6 +294,7 @@
 class LockedFile(object):
   """Represent a file that has exclusive access."""
 
+  @util.positional(4)
   def __init__(self, filename, mode, fallback_mode, use_native_locking=True):
     """Construct a LockedFile.
 
diff --git a/oauth2client/multistore_file.py b/oauth2client/multistore_file.py
index 60ac684..e190c6a 100644
--- a/oauth2client/multistore_file.py
+++ b/oauth2client/multistore_file.py
@@ -38,8 +38,9 @@
 import threading
 
 from anyjson import simplejson
-from client import Storage as BaseStorage
-from client import Credentials
+from oauth2client.client import Storage as BaseStorage
+from oauth2client.client import Credentials
+from oauth2client import util
 from locked_file import LockedFile
 
 logger = logging.getLogger(__name__)
@@ -59,6 +60,7 @@
   pass
 
 
+@util.positional(4)
 def get_credential_storage(filename, client_id, user_agent, scope,
                            warn_on_readonly=True):
   """Get a Storage instance for a credential.
@@ -78,7 +80,7 @@
   _multistores_lock.acquire()
   try:
     multistore = _multistores.setdefault(
-        filename, _MultiStore(filename, warn_on_readonly))
+        filename, _MultiStore(filename, warn_on_readonly=warn_on_readonly))
   finally:
     _multistores_lock.release()
   if type(scope) is list:
@@ -89,6 +91,7 @@
 class _MultiStore(object):
   """A file backed store for multiple credentials."""
 
+  @util.positional(2)
   def __init__(self, filename, warn_on_readonly=True):
     """Initialize the class.
 
diff --git a/oauth2client/tools.py b/oauth2client/tools.py
index 5d96ea4..1faa9ff 100644
--- a/oauth2client/tools.py
+++ b/oauth2client/tools.py
@@ -29,8 +29,9 @@
 import sys
 import webbrowser
 
-from client import FlowExchangeError
-from client import OOB_CALLBACK_URN
+from oauth2client.client import FlowExchangeError
+from oauth2client.client import OOB_CALLBACK_URN
+from oauth2client import util
 
 try:
   from urlparse import parse_qsl
@@ -91,6 +92,7 @@
     pass
 
 
+@util.positional(2)
 def run(flow, storage, http=None):
   """Core code for a command-line application.
 
@@ -130,7 +132,8 @@
     oauth_callback = 'http://%s:%s/' % (FLAGS.auth_host_name, port_number)
   else:
     oauth_callback = OOB_CALLBACK_URN
-  authorize_url = flow.step1_get_authorize_url(oauth_callback)
+  flow.redirect_uri = oauth_callback
+  authorize_url = flow.step1_get_authorize_url()
 
   if FLAGS.auth_local_webserver:
     webbrowser.open(authorize_url, new=1, autoraise=True)
@@ -163,7 +166,7 @@
     code = raw_input('Enter verification code: ').strip()
 
   try:
-    credential = flow.step2_exchange(code, http)
+    credential = flow.step2_exchange(code, http=http)
   except FlowExchangeError, e:
     sys.exit('Authentication has failed: %s' % e)
 
diff --git a/oauth2client/util.py b/oauth2client/util.py
new file mode 100644
index 0000000..bda14c6
--- /dev/null
+++ b/oauth2client/util.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+"""Common utility library."""
+
+__author__ = ['rafek@google.com (Rafe Kaplan)',
+              'guido@google.com (Guido van Rossum)',
+]
+__all__ = [
+  'positional',
+]
+
+import gflags
+import inspect
+import logging
+
+logger = logging.getLogger(__name__)
+
+FLAGS = gflags.FLAGS
+
+gflags.DEFINE_enum('positional_parameters_enforcement', 'WARNING',
+    ['EXCEPTION', 'WARNING', 'IGNORE'],
+    'The action when an oauth2client.util.positional declaration is violated.')
+
+
+def positional(max_positional_args):
+  """A decorator to declare that only the first N arguments my be positional.
+
+  This decorator makes it easy to support Python 3 style key-word only
+  parameters.  For example, in Python 3 it is possible to write:
+
+    def fn(pos1, *, kwonly1=None, kwonly1=None):
+      ...
+
+  All named parameters after * must be a keyword:
+
+    fn(10, 'kw1', 'kw2')  # Raises exception.
+    fn(10, kwonly1='kw1')  # Ok.
+
+  Example:
+    To define a function like above, do:
+
+      @positional(1)
+      def fn(pos1, kwonly1=None, kwonly2=None):
+        ...
+
+    If no default value is provided to a keyword argument, it becomes a required
+    keyword argument:
+
+      @positional(0)
+      def fn(required_kw):
+        ...
+
+    This must be called with the keyword parameter:
+
+      fn()  # Raises exception.
+      fn(10)  # Raises exception.
+      fn(required_kw=10)  # Ok.
+
+    When defining instance or class methods always remember to account for
+    'self' and 'cls':
+
+      class MyClass(object):
+
+        @positional(2)
+        def my_method(self, pos1, kwonly1=None):
+          ...
+
+        @classmethod
+        @positional(2)
+        def my_method(cls, pos1, kwonly1=None):
+          ...
+
+  The positional decorator behavior is controlled by the
+  --positional_parameters_enforcement flag. The flag may be set to 'EXCEPTION',
+  'WARNING' or 'IGNORE' to raise an exception, log a warning, or do nothing,
+  respectively, if a declaration is violated.
+
+  Args:
+    max_positional_arguments: Maximum number of positional arguments.  All
+      parameters after the this index must be keyword only.
+
+  Returns:
+    A decorator that prevents using arguments after max_positional_args from
+    being used as positional parameters.
+
+  Raises:
+    TypeError if a key-word only argument is provided as a positional parameter,
+    but only if the --positional_parameters_enforcement flag is set to
+    'EXCEPTION'.
+  """
+  def positional_decorator(wrapped):
+    def positional_wrapper(*args, **kwargs):
+      if len(args) > max_positional_args:
+        plural_s = ''
+        if max_positional_args != 1:
+          plural_s = 's'
+        message = '%s() takes at most %d positional argument%s (%d given)' % (
+            wrapped.__name__, max_positional_args, plural_s, len(args))
+        if FLAGS.positional_parameters_enforcement == 'EXCEPTION':
+          raise TypeError(message)
+        elif FLAGS.positional_parameters_enforcement == 'WARNING':
+          logger.warning(message)
+        else: # IGNORE
+          pass
+      return wrapped(*args, **kwargs)
+    return positional_wrapper
+
+  if isinstance(max_positional_args, (int, long)):
+    return positional_decorator
+  else:
+    args, _, _, defaults = inspect.getargspec(max_positional_args)
+    return positional(len(args) - len(defaults))(max_positional_args)
diff --git a/runtests.py b/runtests.py
index 9e695ea..0176cc7 100644
--- a/runtests.py
+++ b/runtests.py
@@ -1,14 +1,21 @@
 #!/usr/bin/env python
+import gflags
 import glob
 import imp
 import logging
 import os
 import sys
 import unittest
+
+# import oauth2client.util for its gflags.
+import oauth2client.util
+
 from trace import fullmodname
 
 logging.basicConfig(level=logging.CRITICAL)
 
+FLAGS = gflags.FLAGS
+
 APP_ENGINE_PATH='../google_appengine'
 
 # Conditional import of cleanup function
@@ -26,12 +33,13 @@
 use_library('django', '1.2')
 
 
-def main():
-  for t in sys.argv[1:]:
+def main(argv):
+  argv = FLAGS(argv)
+  for t in argv[1:]:
     module = imp.load_source('test', t)
     test = unittest.TestLoader().loadTestsFromModule(module)
     result = unittest.TextTestRunner(verbosity=1).run(test)
 
 
 if __name__ == '__main__':
-  main()
+  main(sys.argv)
diff --git a/runtests.sh b/runtests.sh
index a4fc9cd..b7e8489 100755
--- a/runtests.sh
+++ b/runtests.sh
@@ -4,18 +4,19 @@
 #
 # The python interpreter to use is passed in on the command line.
 
-$1 runtests.py tests/test_discovery.py
-$1 runtests.py tests/test_errors.py
-$1 runtests.py tests/test_http.py
-$1 runtests.py tests/test_json_model.py
-$1 runtests.py tests/test_mocks.py
-$1 runtests.py tests/test_model.py
-$1 runtests.py tests/test_oauth2client_clientsecrets.py
-$1 runtests.py tests/test_oauth2client_django_orm.py
-$1 runtests.py tests/test_oauth2client_file.py
-$1 runtests.py tests/test_oauth2client_jwt.py
-$1 runtests.py tests/test_oauth2client.py
-$1 runtests.py tests/test_protobuf_model.py
-$1 runtests.py tests/test_schema.py
-$1 runtests.py tests/test_oauth2client_appengine.py
-$1 runtests.py tests/test_oauth2client_keyring.py
+FLAGS=--positional_parameters_enforcement=EXCEPTION
+$1 runtests.py $FLAGS tests/test_discovery.py
+$1 runtests.py $FLAGS tests/test_errors.py
+$1 runtests.py $FLAGS tests/test_http.py
+$1 runtests.py $FLAGS tests/test_json_model.py
+$1 runtests.py $FLAGS tests/test_mocks.py
+$1 runtests.py $FLAGS tests/test_model.py
+$1 runtests.py $FLAGS tests/test_oauth2client_clientsecrets.py
+$1 runtests.py $FLAGS tests/test_oauth2client_django_orm.py
+$1 runtests.py $FLAGS tests/test_oauth2client_file.py
+$1 runtests.py $FLAGS tests/test_oauth2client_jwt.py
+$1 runtests.py $FLAGS tests/test_oauth2client.py
+$1 runtests.py $FLAGS tests/test_protobuf_model.py
+$1 runtests.py $FLAGS tests/test_schema.py
+$1 runtests.py $FLAGS tests/test_oauth2client_appengine.py
+$1 runtests.py $FLAGS tests/test_oauth2client_keyring.py
diff --git a/samples/adexchangebuyer/sample_utils.py b/samples/adexchangebuyer/sample_utils.py
index fd04097..89f95ff 100644
--- a/samples/adexchangebuyer/sample_utils.py
+++ b/samples/adexchangebuyer/sample_utils.py
@@ -28,6 +28,7 @@
 import gflags
 import httplib2
 from oauth2client.client import flow_from_clientsecrets
+from oauth2client.client import OOB_CALLBACK_URN
 from oauth2client.file import Storage
 from oauth2client.tools import run
 
@@ -58,6 +59,7 @@
 FLOW = flow_from_clientsecrets(
     CLIENT_SECRETS,
     scope='https://www.googleapis.com/auth/adexchange.buyer',
+    redirect_uri=OOB_CALLBACK_URN,
     message=MISSING_CLIENT_SECRETS_MESSAGE
     )
 
@@ -108,4 +110,3 @@
   # Construct a service object via the discovery service.
   service = build('adexchangebuyer', 'v1', http=http)
   return service
- 
diff --git a/samples/adsense/sample_utils.py b/samples/adsense/sample_utils.py
index f057e04..25bd3e9 100644
--- a/samples/adsense/sample_utils.py
+++ b/samples/adsense/sample_utils.py
@@ -28,6 +28,7 @@
 import gflags
 import httplib2
 from oauth2client.client import flow_from_clientsecrets
+from oauth2client.client import OOB_CALLBACK_URN
 from oauth2client.file import Storage
 from oauth2client.tools import run
 
@@ -57,6 +58,7 @@
 # Set up a Flow object to be used if we need to authenticate.
 FLOW = flow_from_clientsecrets(CLIENT_SECRETS,
     scope='https://www.googleapis.com/auth/adsense.readonly',
+    redirect_uri=OOB_CALLBACK_URN,
     message=MISSING_CLIENT_SECRETS_MESSAGE)
 
 # The gflags module makes defining command-line options easy for applications.
diff --git a/samples/analytics/sample_utils.py b/samples/analytics/sample_utils.py
index c397bf8..10aa12c 100644
--- a/samples/analytics/sample_utils.py
+++ b/samples/analytics/sample_utils.py
@@ -40,6 +40,7 @@
 import gflags
 import httplib2
 from oauth2client.client import flow_from_clientsecrets
+from oauth2client.client import OOB_CALLBACK_URN
 from oauth2client.file import Storage
 from oauth2client.tools import run
 
@@ -70,6 +71,7 @@
 # Set up a Flow object to be used if we need to authenticate.
 FLOW = flow_from_clientsecrets(CLIENT_SECRETS,
     scope='https://www.googleapis.com/auth/analytics.readonly',
+    redirect_uri=OOB_CALLBACK_URN,
     message=MISSING_CLIENT_SECRETS_MESSAGE)
 
 # The gflags module makes defining command-line options easy for applications.
diff --git a/samples/appengine/app.yaml b/samples/appengine/app.yaml
index bdc4be1..1361642 100644
--- a/samples/appengine/app.yaml
+++ b/samples/appengine/app.yaml
@@ -4,9 +4,6 @@
 api_version: 1
 
 handlers:
-- url: /oauth2callback
-  script: oauth2client/appengine.py
-
 - url: .*
   script: main.py
 
diff --git a/samples/appengine/main.py b/samples/appengine/main.py
index 309376c..f649bfb 100644
--- a/samples/appengine/main.py
+++ b/samples/appengine/main.py
@@ -66,8 +66,8 @@
 service = build("plus", "v1", http=http)
 decorator = oauth2decorator_from_clientsecrets(
     CLIENT_SECRETS,
-    'https://www.googleapis.com/auth/plus.me',
-    MISSING_CLIENT_SECRETS_MESSAGE)
+    scope='https://www.googleapis.com/auth/plus.me',
+    message=MISSING_CLIENT_SECRETS_MESSAGE)
 
 class MainHandler(webapp.RequestHandler):
 
@@ -87,7 +87,7 @@
   def get(self):
     try:
       http = decorator.http()
-      user = service.people().get(userId='me').execute(http)
+      user = service.people().get(userId='me').execute(http=http)
       text = 'Hello, %s!' % user['displayName']
 
       path = os.path.join(os.path.dirname(__file__), 'welcome.html')
@@ -101,6 +101,7 @@
       [
        ('/', MainHandler),
        ('/about', AboutHandler),
+       (decorator.callback_path, decorator.callback_handler()),
       ],
       debug=True)
   run_wsgi_app(application)
diff --git a/samples/blogger/blogger.py b/samples/blogger/blogger.py
index da67afe..8e3ccdd 100644
--- a/samples/blogger/blogger.py
+++ b/samples/blogger/blogger.py
@@ -113,7 +113,7 @@
       users = service.users()
 
       # Retrieve this user's profile information
-      thisuser = users.get(userId="self").execute(http)
+      thisuser = users.get(userId="self").execute(http=http)
       print "This user's display name is: %s" % thisuser['displayName']
 
       # Retrieve the list of Blogs this user has write privileges on
@@ -128,7 +128,7 @@
         print "The posts for %s:" % blog['name']
         request = posts.list(blogId=blog['id'])
         while request != None:
-          posts_doc = request.execute(http)
+          posts_doc = request.execute(http=http)
           if 'items' in posts_doc and not (posts_doc['items'] is None):
             for post in posts_doc['items']:
               print "  %s (%s)" % (post['title'], post['url'])
diff --git a/samples/coordinate/coordinate.py b/samples/coordinate/coordinate.py
index ef426dc..49ca852 100644
--- a/samples/coordinate/coordinate.py
+++ b/samples/coordinate/coordinate.py
@@ -128,7 +128,7 @@
 
   try:
     # List all the jobs for a team
-    jobs_result = service.jobs().list(teamId=FLAGS.teamId).execute(http)
+    jobs_result = service.jobs().list(teamId=FLAGS.teamId).execute(http=http)
 
     print('List of Jobs:')
     pprint.pprint(jobs_result)
diff --git a/samples/dailymotion/main.py b/samples/dailymotion/main.py
index 1b75239..7f7256f 100644
--- a/samples/dailymotion/main.py
+++ b/samples/dailymotion/main.py
@@ -26,7 +26,6 @@
 from oauth2client.appengine import CredentialsProperty
 from oauth2client.appengine import StorageByKeyName
 from oauth2client.client import OAuth2WebServerFlow
-from google.appengine.api import memcache
 from google.appengine.api import users
 from google.appengine.ext import db
 from google.appengine.ext import webapp
@@ -39,6 +38,7 @@
     client_id='2ad565600216d25d9cde',
     client_secret='03b56df2949a520be6049ff98b89813f17b467dc',
     scope='read',
+    redirect_uri='https://dailymotoauth2test.appspot.com/auth_return',
     user_agent='oauth2client-sample/1.0',
     auth_uri='https://api.dailymotion.com/oauth/authorize',
     token_uri='https://api.dailymotion.com/oauth/token'
@@ -58,9 +58,7 @@
         Credentials, user.user_id(), 'credentials').get()
 
     if credentials is None or credentials.invalid == True:
-      callback = self.request.relative_url('/auth_return')
-      authorize_url = FLOW.step1_get_authorize_url(callback)
-      memcache.set(user.user_id(), pickle.dumps(FLOW))
+      authorize_url = FLOW.step1_get_authorize_url()
       self.redirect(authorize_url)
     else:
       http = httplib2.Http()
@@ -82,14 +80,10 @@
   @login_required
   def get(self):
     user = users.get_current_user()
-    flow = pickle.loads(memcache.get(user.user_id()))
-    if flow:
-      credentials = flow.step2_exchange(self.request.params)
-      StorageByKeyName(
-          Credentials, user.user_id(), 'credentials').put(credentials)
-      self.redirect("/")
-    else:
-      pass
+    credentials = FLOW.step2_exchange(self.request.params)
+    StorageByKeyName(
+        Credentials, user.user_id(), 'credentials').put(credentials)
+    self.redirect("/")
 
 
 def main():
diff --git a/samples/django_sample/plus/models.py b/samples/django_sample/plus/models.py
index 69c180c..fd4bf74 100644
--- a/samples/django_sample/plus/models.py
+++ b/samples/django_sample/plus/models.py
@@ -8,13 +8,6 @@
 from oauth2client.django_orm import FlowField
 from oauth2client.django_orm import CredentialsField
 
-# The Flow could also be stored in memcache since it is short lived.
-
-
-class FlowModel(models.Model):
-  id = models.ForeignKey(User, primary_key=True)
-  flow = FlowField()
-
 
 class CredentialsModel(models.Model):
   id = models.ForeignKey(User, primary_key=True)
@@ -30,4 +23,3 @@
 
 
 admin.site.register(CredentialsModel, CredentialsAdmin)
-admin.site.register(FlowModel, FlowAdmin)
diff --git a/samples/django_sample/plus/views.py b/samples/django_sample/plus/views.py
index 8cc5838..f5d5d18 100644
--- a/samples/django_sample/plus/views.py
+++ b/samples/django_sample/plus/views.py
@@ -9,7 +9,6 @@
 from oauth2client.django_orm import Storage
 from oauth2client.client import OAuth2WebServerFlow
 from django_sample.plus.models import CredentialsModel
-from django_sample.plus.models import FlowModel
 from apiclient.discovery import build
 
 from django.http import HttpResponseRedirect
@@ -17,22 +16,21 @@
 
 STEP2_URI = 'http://localhost:8000/oauth2callback'
 
+FLOW = OAuth2WebServerFlow(
+    client_id='[[Insert Client ID here.]]',
+    client_secret='[[Insert Client Secret here.]]',
+    scope='https://www.googleapis.com/auth/plus.me',
+    redirect_uri=STEP2_URI,
+    user_agent='plus-django-sample/1.0',
+    )
+
 
 @login_required
 def index(request):
   storage = Storage(CredentialsModel, 'id', request.user, 'credential')
   credential = storage.get()
   if credential is None or credential.invalid == True:
-    flow = OAuth2WebServerFlow(
-        client_id='[[Insert Client ID here.]]',
-        client_secret='[[Insert Client Secret here.]]',
-        scope='https://www.googleapis.com/auth/plus.me',
-        user_agent='plus-django-sample/1.0',
-        )
-
-    authorize_url = flow.step1_get_authorize_url(STEP2_URI)
-    f = FlowModel(id=request.user, flow=flow)
-    f.save()
+    authorize_url = FLOW.step1_get_authorize_url()
     return HttpResponseRedirect(authorize_url)
   else:
     http = httplib2.Http()
@@ -50,12 +48,7 @@
 
 @login_required
 def auth_return(request):
-    try:
-      f = FlowModel.objects.get(id=request.user)
-      credential = f.flow.step2_exchange(request.REQUEST)
-      storage = Storage(CredentialsModel, 'id', request.user, 'credential')
-      storage.put(credential)
-      f.delete()
-      return HttpResponseRedirect("/")
-    except FlowModel.DoesNotExist:
-      pass
+  credential = FLOW.step2_exchange(request.REQUEST)
+  storage = Storage(CredentialsModel, 'id', request.user, 'credential')
+  storage.put(credential)
+  return HttpResponseRedirect("/")
diff --git a/samples/plus/plus.py b/samples/plus/plus.py
index 6b9dbf0..c6089f9 100644
--- a/samples/plus/plus.py
+++ b/samples/plus/plus.py
@@ -113,7 +113,7 @@
   service = build("plus", "v1", http=http)
 
   try:
-    person = service.people().get(userId='me').execute(http)
+    person = service.people().get(userId='me').execute(http=http)
 
     print "Got your ID: %s" % person['displayName']
     print
diff --git a/samples/service_account/tasks.py b/samples/service_account/tasks.py
index bb9cd1a..54f4936 100644
--- a/samples/service_account/tasks.py
+++ b/samples/service_account/tasks.py
@@ -57,7 +57,7 @@
   service = build("tasks", "v1", http=http)
 
   # List all the tasklists for the account.
-  lists = service.tasklists().list().execute(http)
+  lists = service.tasklists().list().execute(http=http)
   pprint.pprint(lists)
 
 
diff --git a/samples/tasks_appengine/app.yaml b/samples/tasks_appengine/app.yaml
index 35a7dc6..27372f7 100644
--- a/samples/tasks_appengine/app.yaml
+++ b/samples/tasks_appengine/app.yaml
@@ -4,9 +4,8 @@
 api_version: 1
 
 handlers:
-- url: /oauth2callback
-  script: oauth2client/appengine.py
 - url: /css
   static_dir: css
+
 - url: .*
   script: main.py
diff --git a/samples/tasks_appengine/main.py b/samples/tasks_appengine/main.py
index 54260bd..64ccb68 100644
--- a/samples/tasks_appengine/main.py
+++ b/samples/tasks_appengine/main.py
@@ -50,7 +50,10 @@
 def truncate(s, l):
   return s[:l] + '...' if len(s) > l else s
 
-application = webapp.WSGIApplication([('/', MainHandler)], debug=True)
+application = webapp.WSGIApplication([
+    ('/', MainHandler),
+    (decorator.callback_path, decorator.callback_handler()),
+    ], debug=True)
 
 
 def main():
diff --git a/samples/threadqueue/main.py b/samples/threadqueue/main.py
index 817de59..5b9764a 100644
--- a/samples/threadqueue/main.py
+++ b/samples/threadqueue/main.py
@@ -100,7 +100,7 @@
       backoff = Backoff()
       while backoff.loop():
         try:
-          response = request.execute(http)
+          response = request.execute(http=http)
           print "Processed: %s in thread %d" % (response['id'], n)
           break
         except HttpError, e:
diff --git a/samples/tz/README b/samples/tz/README
deleted file mode 100644
index 1afa540..0000000
--- a/samples/tz/README
+++ /dev/null
@@ -1,36 +0,0 @@
-This is an example program that can run as a power
-management hook to set the timezone on the computer
-based on the user's location, as determined by Google
-Latitude. To use this application you will need Google
-Latitude running on a mobile device.
-
-api: latitude
-keywords: cmdline
-
-Installation
-============
-  The google-api-python-client library will need to
-be installed.
-
-$ sudo python setup.py install
-
-Then you will need to install the tznever application:
-
-$ sudo cp tznever /usr/sbin/tznever
-
-And then add it in as a power management hook:
-
-$ sudo ln -s /usr/sbin/tznever /etc/pm/sleep.d/45tznever
-
-Once that is done you need to run tznever once from the
-the command line to tie it to your Latitude account:
-
-$ sudo tznever
-
-After that, every time your laptop resumes it will
-check you Latitude location and set the timezone
-accordingly.
-
-TODO
-====
-1. What about stale Latitude data?
diff --git a/samples/tz/tznever b/samples/tz/tznever
deleted file mode 100755
index b9331bb..0000000
--- a/samples/tz/tznever
+++ /dev/null
@@ -1,289 +0,0 @@
-#!/usr/bin/python
-# -*- coding: utf-8 -*-
-#
-# Copyright 2010 Google Inc. All Rights Reserved.
-# Portions copyright PSF License
-#   http://code.activestate.com/recipes/278731-creating-a-daemon-the-python-way/
-
-"""A pm-action hook for setting timezone.
-
-Uses the Google Latitude API and the geonames.org
-API to find your cellphones latitude and longitude
-and from the determine the timezone you are in,
-and then sets the computer's timezone to that.
-"""
-
-__author__ = 'jcgregorio@google.com (Joe Gregorio)'
-
-
-from apiclient.discovery import build
-
-import httplib2
-import os
-import pickle
-import pprint
-import subprocess
-import sys
-import time
-import uritemplate
-
-from apiclient.anyjson import simplejson
-from apiclient.discovery import build
-from apiclient.oauth import FlowThreeLegged
-from apiclient.ext.authtools import run
-from apiclient.ext.file import Storage
-
-# Uncomment to get detailed logging
-# httplib2.debuglevel = 4
-
-# URI Template to convert latitude and longitude into a timezone
-GEONAMES = 'http://api.geonames.org/timezoneJSON?lat={lat}&lng={long}&username=jcgregorio'
-PID_FILE = '/var/lock/tznever.pid'
-CACHE = '/var/local/tznever/.cache'
-
-# Default daemon parameters.
-# File mode creation mask of the daemon.
-UMASK = 0
-
-# Default working directory for the daemon.
-WORKDIR = "/"
-
-# Default maximum for the number of available file descriptors.
-MAXFD = 1024
-
-# The standard I/O file descriptors are redirected to /dev/null by default.
-if (hasattr(os, "devnull")):
-   REDIRECT_TO = os.devnull
-else:
-   REDIRECT_TO = "/dev/null"
-
-
-def main():
-  storage = Storage('/var/local/tznever/latitude_credentials.dat')
-  credentials = storage.get()
-  if len(sys.argv) == 1:
-    if credentials is None or credentials.invalid == True:
-      auth_discovery = build('latitude', 'v1').auth_discovery()
-      flow = FlowThreeLegged(auth_discovery,
-          consumer_key='m-buzz.appspot.com',
-          consumer_secret='NQEHb4eU6GkjjFGe1MD5W6IC',
-          user_agent='tz-never/1.0',
-          domain='m-buzz.appspot.com',
-          scope='https://www.googleapis.com/auth/latitude',
-          xoauth_displayname='TZ Never Again',
-          location='current',
-          granularity='city'
-          )
-
-      credentials = run(flow, storage)
-    else:
-      print "You are already authorized"
-  else:
-    if credentials is None or credentials.invalid == True:
-      print "This app, tznever, is not authorized. Run from the command-line to re-authorize."
-      os.exit(1)
-
-  if len(sys.argv) > 1 and sys.argv[1] in ['hibernate', 'suspend']:
-    print "Hibernating"
-    # Kill off the possibly still running process by its pid
-    if os.path.isfile(PID_FILE):
-      f = file(PID_FILE, 'r')
-      pid = f.read()
-      f.close()
-      cmdline = ['/bin/kill', '-2', pid]
-      subprocess.Popen(cmdline)
-      os.unlink(PID_FILE)
-  elif len(sys.argv) > 1 and sys.argv[1] in ['thaw', 'resume']:
-    print "Resuming"
-    # write our pid out
-    f = file(PID_FILE, 'w')
-    f.write(str(os.getpid()))
-    f.close()
-
-    success = False
-    first_time = True
-    while not success:
-      try:
-        if not first_time:
-          time.sleep(5)
-        else:
-          first_time = False
-          print "Daemonizing so as not to gum up the works."
-          createDaemon()
-          # rewrite the PID file with our new PID
-          f = file(PID_FILE, 'w')
-          f.write(str(os.getpid()))
-          f.close()
-        http = httplib2.Http(CACHE)
-        http = credentials.authorize(http)
-
-        service = build('latitude', 'v1', http=http)
-
-        location = service.currentLocation().get(granularity='city').execute()
-        position = {
-            'lat': str(location['latitude']),
-            'long': str(location['longitude'])
-            }
-        http2 = httplib2.Http(CACHE)
-        resp, content = http2.request(uritemplate.expand(GEONAMES, position))
-        geodata = simplejson.loads(content)
-        tz = geodata['timezoneId']
-        f = file('/etc/timezone', 'w')
-        f.write(tz)
-        f.close()
-        cmdline = 'dpkg-reconfigure -f noninteractive tzdata'.split(' ')
-        subprocess.Popen(cmdline)
-        success = True
-      except httplib2.ServerNotFoundError, e:
-        print "still not connected, sleeping"
-      except KeyboardInterrupt, e:
-        if os.path.isfile(PID_FILE):
-          os.unlink(PID_FILE)
-        success = True
-    # clean up pid file
-    if os.path.isfile(PID_FILE):
-      os.unlink(PID_FILE)
-
-
-def createDaemon():
-   """Detach a process from the controlling terminal and run it in the
-   background as a daemon.
-   """
-
-   try:
-      # Fork a child process so the parent can exit.  This returns control to
-      # the command-line or shell.  It also guarantees that the child will not
-      # be a process group leader, since the child receives a new process ID
-      # and inherits the parent's process group ID.  This step is required
-      # to insure that the next call to os.setsid is successful.
-      pid = os.fork()
-   except OSError, e:
-      raise Exception, "%s [%d]" % (e.strerror, e.errno)
-
-   if (pid == 0):	# The first child.
-      # To become the session leader of this new session and the process group
-      # leader of the new process group, we call os.setsid().  The process is
-      # also guaranteed not to have a controlling terminal.
-      os.setsid()
-
-      # Is ignoring SIGHUP necessary?
-      #
-      # It's often suggested that the SIGHUP signal should be ignored before
-      # the second fork to avoid premature termination of the process.  The
-      # reason is that when the first child terminates, all processes, e.g.
-      # the second child, in the orphaned group will be sent a SIGHUP.
-      #
-      # "However, as part of the session management system, there are exactly
-      # two cases where SIGHUP is sent on the death of a process:
-      #
-      #   1) When the process that dies is the session leader of a session that
-      #      is attached to a terminal device, SIGHUP is sent to all processes
-      #      in the foreground process group of that terminal device.
-      #   2) When the death of a process causes a process group to become
-      #      orphaned, and one or more processes in the orphaned group are
-      #      stopped, then SIGHUP and SIGCONT are sent to all members of the
-      #      orphaned group." [2]
-      #
-      # The first case can be ignored since the child is guaranteed not to have
-      # a controlling terminal.  The second case isn't so easy to dismiss.
-      # The process group is orphaned when the first child terminates and
-      # POSIX.1 requires that every STOPPED process in an orphaned process
-      # group be sent a SIGHUP signal followed by a SIGCONT signal.  Since the
-      # second child is not STOPPED though, we can safely forego ignoring the
-      # SIGHUP signal.  In any case, there are no ill-effects if it is ignored.
-      #
-      # import signal           # Set handlers for asynchronous events.
-      # signal.signal(signal.SIGHUP, signal.SIG_IGN)
-
-      try:
-         # Fork a second child and exit immediately to prevent zombies.  This
-         # causes the second child process to be orphaned, making the init
-         # process responsible for its cleanup.  And, since the first child is
-         # a session leader without a controlling terminal, it's possible for
-         # it to acquire one by opening a terminal in the future (System V-
-         # based systems).  This second fork guarantees that the child is no
-         # longer a session leader, preventing the daemon from ever acquiring
-         # a controlling terminal.
-         pid = os.fork()	# Fork a second child.
-      except OSError, e:
-         raise Exception, "%s [%d]" % (e.strerror, e.errno)
-
-      if (pid == 0):	# The second child.
-         # Since the current working directory may be a mounted filesystem, we
-         # avoid the issue of not being able to unmount the filesystem at
-         # shutdown time by changing it to the root directory.
-         os.chdir(WORKDIR)
-         # We probably don't want the file mode creation mask inherited from
-         # the parent, so we give the child complete control over permissions.
-         os.umask(UMASK)
-      else:
-         # exit() or _exit()?  See below.
-         os._exit(0)	# Exit parent (the first child) of the second child.
-   else:
-      # exit() or _exit()?
-      # _exit is like exit(), but it doesn't call any functions registered
-      # with atexit (and on_exit) or any registered signal handlers.  It also
-      # closes any open file descriptors.  Using exit() may cause all stdio
-      # streams to be flushed twice and any temporary files may be unexpectedly
-      # removed.  It's therefore recommended that child branches of a fork()
-      # and the parent branch(es) of a daemon use _exit().
-      os._exit(0)	# Exit parent of the first child.
-
-   # Close all open file descriptors.  This prevents the child from keeping
-   # open any file descriptors inherited from the parent.  There is a variety
-   # of methods to accomplish this task.  Three are listed below.
-   #
-   # Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
-   # number of open file descriptors to close.  If it doesn't exists, use
-   # the default value (configurable).
-   #
-   # try:
-   #    maxfd = os.sysconf("SC_OPEN_MAX")
-   # except (AttributeError, ValueError):
-   #    maxfd = MAXFD
-   #
-   # OR
-   #
-   # if (os.sysconf_names.has_key("SC_OPEN_MAX")):
-   #    maxfd = os.sysconf("SC_OPEN_MAX")
-   # else:
-   #    maxfd = MAXFD
-   #
-   # OR
-   #
-   # Use the getrlimit method to retrieve the maximum file descriptor number
-   # that can be opened by this process.  If there is not limit on the
-   # resource, use the default value.
-   #
-   import resource		# Resource usage information.
-   maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
-   if (maxfd == resource.RLIM_INFINITY):
-      maxfd = MAXFD
-
-   # Iterate through and close all file descriptors.
-   for fd in range(0, maxfd):
-      try:
-         os.close(fd)
-      except OSError:	# ERROR, fd wasn't open to begin with (ignored)
-         pass
-
-   # Redirect the standard I/O file descriptors to the specified file.  Since
-   # the daemon has no controlling terminal, most daemons redirect stdin,
-   # stdout, and stderr to /dev/null.  This is done to prevent side-effects
-   # from reads and writes to the standard I/O file descriptors.
-
-   # This call to open is guaranteed to return the lowest file descriptor,
-   # which will be 0 (stdin), since it was closed above.
-   os.open(REDIRECT_TO, os.O_RDWR)	# standard input (0)
-
-   # Duplicate standard input to standard output and standard error.
-   os.dup2(0, 1)			# standard output (1)
-   os.dup2(0, 2)			# standard error (2)
-
-   return(0)
-
-if __name__ == '__main__':
-  main()
-
-
-
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index b1656c4..b2f69c5 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -64,10 +64,17 @@
 
 class DiscoveryErrors(unittest.TestCase):
 
+  def test_tests_should_be_run_with_strict_positional_enforcement(self):
+    try:
+      plus = build('plus', 'v1', None)
+      self.fail("should have raised a TypeError exception over missing http=.")
+    except TypeError:
+      pass
+
   def test_failed_to_parse_discovery_json(self):
     self.http = HttpMock(datafile('malformed.json'), {'status': '200'})
     try:
-      plus = build('plus', 'v1', self.http)
+      plus = build('plus', 'v1', http=self.http)
       self.fail("should have raised an exception over malformed JSON.")
     except InvalidJsonError:
       pass
@@ -103,7 +110,7 @@
       http = HttpMockSequence([
         ({'status': '400'}, file(datafile('zoo.json'), 'r').read()),
         ])
-      zoo = build('zoo', 'v1', http, developerKey='foo',
+      zoo = build('zoo', 'v1', http=http, developerKey='foo',
                   discoveryServiceUrl='http://example.com')
       self.fail('Should have raised an exception.')
     except HttpError, e:
@@ -116,7 +123,7 @@
       http = HttpMockSequence([
         ({'status': '400'}, file(datafile('zoo.json'), 'r').read()),
         ])
-      zoo = build('zoo', 'v1', http, developerKey=None,
+      zoo = build('zoo', 'v1', http=http, developerKey=None,
                   discoveryServiceUrl='http://example.com')
       self.fail('Should have raised an exception.')
     except HttpError, e:
@@ -127,7 +134,7 @@
 
   def test_method_error_checking(self):
     self.http = HttpMock(datafile('plus.json'), {'status': '200'})
-    plus = build('plus', 'v1', self.http)
+    plus = build('plus', 'v1', http=self.http)
 
     # Missing required parameters
     try:
@@ -170,7 +177,7 @@
 
   def test_type_coercion(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
 
     request = zoo.query(
         q="foo", i=1.0, n=1.0, b=0, a=[1,2,3], o={'a':1}, e='bar')
@@ -192,7 +199,7 @@
 
   def test_optional_stack_query_parameters(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.query(trace='html', fields='description')
 
     parsed = urlparse.urlparse(request.uri)
@@ -202,7 +209,7 @@
 
   def test_string_params_value_of_none_get_dropped(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.query(trace=None, fields='description')
 
     parsed = urlparse.urlparse(request.uri)
@@ -211,7 +218,7 @@
 
   def test_model_added_query_parameters(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.animals().get(name='Lion')
 
     parsed = urlparse.urlparse(request.uri)
@@ -221,7 +228,7 @@
 
   def test_fallback_to_raw_model(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.animals().getmedia(name='Lion')
 
     parsed = urlparse.urlparse(request.uri)
@@ -231,7 +238,7 @@
 
   def test_patch(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.animals().patch(name='lion', body='{"description": "foo"}')
 
     self.assertEqual(request.method, 'PATCH')
@@ -242,7 +249,7 @@
       ({'status': '200'}, 'echo_request_headers_as_json'),
       ])
     http = tunnel_patch(http)
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     resp = zoo.animals().patch(
         name='lion', body='{"description": "foo"}').execute()
 
@@ -250,7 +257,7 @@
 
   def test_plus_resources(self):
     self.http = HttpMock(datafile('plus.json'), {'status': '200'})
-    plus = build('plus', 'v1', self.http)
+    plus = build('plus', 'v1', http=self.http)
     self.assertTrue(getattr(plus, 'activities'))
     self.assertTrue(getattr(plus, 'people'))
 
@@ -258,7 +265,7 @@
     # Zoo should exercise all discovery facets
     # and should also have no future.json file.
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     self.assertTrue(getattr(zoo, 'animals'))
 
     request = zoo.animals().list(name='bat', projection="full")
@@ -269,7 +276,7 @@
 
   def test_nested_resources(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     self.assertTrue(getattr(zoo, 'animals'))
     request = zoo.my().favorites().list(max_results="5")
     parsed = urlparse.urlparse(request.uri)
@@ -278,7 +285,7 @@
 
   def test_methods_with_reserved_names(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     self.assertTrue(getattr(zoo, 'animals'))
     request = zoo.global_().print_().assert_(max_results="5")
     parsed = urlparse.urlparse(request.uri)
@@ -286,7 +293,7 @@
 
   def test_top_level_functions(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     self.assertTrue(getattr(zoo, 'query'))
     request = zoo.query(q="foo")
     parsed = urlparse.urlparse(request.uri)
@@ -295,20 +302,20 @@
 
   def test_simple_media_uploads(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     doc = getattr(zoo.animals().insert, '__doc__')
     self.assertTrue('media_body' in doc)
 
   def test_simple_media_upload_no_max_size_provided(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
     request = zoo.animals().crossbreed(media_body=datafile('small.png'))
     self.assertEquals('image/png', request.headers['content-type'])
     self.assertEquals('PNG', request.body[1:4])
 
   def test_simple_media_raise_correct_exceptions(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     try:
       zoo.animals().insert(media_body=datafile('smiley.png'))
@@ -324,7 +331,7 @@
 
   def test_simple_media_good_upload(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     request = zoo.animals().insert(media_body=datafile('small.png'))
     self.assertEquals('image/png', request.headers['content-type'])
@@ -335,7 +342,7 @@
 
   def test_multipart_media_raise_correct_exceptions(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     try:
       zoo.animals().insert(media_body=datafile('smiley.png'), body={})
@@ -351,7 +358,7 @@
 
   def test_multipart_media_good_upload(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     request = zoo.animals().insert(media_body=datafile('small.png'), body={})
     self.assertTrue(request.headers['content-type'].startswith(
@@ -363,14 +370,14 @@
 
   def test_media_capable_method_without_media(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     request = zoo.animals().insert(body={})
     self.assertTrue(request.headers['content-type'], 'application/json')
 
   def test_resumable_multipart_media_good_upload(self):
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     media_upload = MediaFileUpload(datafile('small.png'), resumable=True)
     request = zoo.animals().insert(media_body=media_upload, body={})
@@ -396,7 +403,7 @@
       ({'status': '200'}, '{"foo": "bar"}'),
       ])
 
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(None, body)
     self.assertTrue(isinstance(status, MediaUploadProgress))
     self.assertEquals(13, status.resumable_progress)
@@ -408,13 +415,13 @@
     self.assertEquals(media_upload, request.resumable)
     self.assertEquals(13, request.resumable_progress)
 
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(request.resumable_uri, 'http://upload.example.com/3')
     self.assertEquals(media_upload.size()-1, request.resumable_progress)
     self.assertEquals('{"data": {}}', request.body)
 
     # Final call to next_chunk should complete the upload.
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(body, {"foo": "bar"})
     self.assertEquals(status, None)
 
@@ -422,7 +429,7 @@
   def test_resumable_media_good_upload(self):
     """Not a multipart upload."""
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     media_upload = MediaFileUpload(datafile('small.png'), resumable=True)
     request = zoo.animals().insert(media_body=media_upload, body=None)
@@ -445,7 +452,7 @@
       ({'status': '200'}, '{"foo": "bar"}'),
       ])
 
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(None, body)
     self.assertTrue(isinstance(status, MediaUploadProgress))
     self.assertEquals(13, status.resumable_progress)
@@ -457,13 +464,13 @@
     self.assertEquals(media_upload, request.resumable)
     self.assertEquals(13, request.resumable_progress)
 
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(request.resumable_uri, 'http://upload.example.com/3')
     self.assertEquals(media_upload.size()-1, request.resumable_progress)
     self.assertEquals(request.body, None)
 
     # Final call to next_chunk should complete the upload.
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(body, {"foo": "bar"})
     self.assertEquals(status, None)
 
@@ -471,7 +478,7 @@
   def test_resumable_media_good_upload_from_execute(self):
     """Not a multipart upload."""
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     media_upload = MediaFileUpload(datafile('small.png'), resumable=True)
     request = zoo.animals().insert(media_body=media_upload, body=None)
@@ -491,13 +498,13 @@
       ({'status': '200'}, '{"foo": "bar"}'),
       ])
 
-    body = request.execute(http)
+    body = request.execute(http=http)
     self.assertEquals(body, {"foo": "bar"})
 
   def test_resumable_media_fail_unknown_response_code_first_request(self):
     """Not a multipart upload."""
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     media_upload = MediaFileUpload(datafile('small.png'), resumable=True)
     request = zoo.animals().insert(media_body=media_upload, body=None)
@@ -507,12 +514,12 @@
         'location': 'http://upload.example.com'}, ''),
       ])
 
-    self.assertRaises(ResumableUploadError, request.execute, http)
+    self.assertRaises(ResumableUploadError, request.execute, http=http)
 
   def test_resumable_media_fail_unknown_response_code_subsequent_request(self):
     """Not a multipart upload."""
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     media_upload = MediaFileUpload(datafile('small.png'), resumable=True)
     request = zoo.animals().insert(media_body=media_upload, body=None)
@@ -523,7 +530,7 @@
       ({'status': '400'}, ''),
       ])
 
-    self.assertRaises(HttpError, request.execute, http)
+    self.assertRaises(HttpError, request.execute, http=http)
     self.assertTrue(request._in_error_state)
 
     http = HttpMockSequence([
@@ -533,7 +540,7 @@
         'range': '0-6'}, ''),
       ])
 
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEquals(status.resumable_progress, 7,
       'Should have first checked length and then tried to PUT more.')
     self.assertFalse(request._in_error_state)
@@ -542,14 +549,14 @@
     http = HttpMockSequence([
       ({'status': '400'}, ''),
       ])
-    self.assertRaises(HttpError, request.execute, http)
+    self.assertRaises(HttpError, request.execute, http=http)
     self.assertTrue(request._in_error_state)
 
     # Pretend the last request that 400'd actually succeeded.
     http = HttpMockSequence([
       ({'status': '200'}, '{"foo": "bar"}'),
       ])
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEqual(body, {'foo': 'bar'})
 
   def test_resumable_media_handle_uploads_of_unknown_size(self):
@@ -560,7 +567,7 @@
       ])
 
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     fd = StringIO.StringIO('data goes here')
 
@@ -569,7 +576,7 @@
         fd=fd, mimetype='image/png', chunksize=10, resumable=True)
 
     request = zoo.animals().insert(media_body=upload, body=None)
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEqual(body, {'Content-Range': 'bytes 0-9/*'},
       'Should be 10 out of * bytes.')
 
@@ -581,7 +588,7 @@
       ])
 
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     fd = StringIO.StringIO('data goes here')
 
@@ -590,7 +597,7 @@
         fd=fd, mimetype='image/png', chunksize=15, resumable=True)
 
     request = zoo.animals().insert(media_body=upload, body=None)
-    status, body = request.next_chunk(http)
+    status, body = request.next_chunk(http=http)
     self.assertEqual(body, {'Content-Range': 'bytes 0-13/14'})
 
   def test_resumable_media_handle_resume_of_upload_of_unknown_size(self):
@@ -601,7 +608,7 @@
       ])
 
     self.http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', self.http)
+    zoo = build('zoo', 'v1', http=self.http)
 
     # Create an upload that doesn't know the full size of the media.
     fd = StringIO.StringIO('data goes here')
@@ -612,7 +619,7 @@
     request = zoo.animals().insert(media_body=upload, body=None)
 
     # Put it in an error state.
-    self.assertRaises(HttpError, request.next_chunk, http)
+    self.assertRaises(HttpError, request.next_chunk, http=http)
 
     http = HttpMockSequence([
       ({'status': '400',
@@ -620,7 +627,7 @@
       ])
     try:
       # Should resume the upload by first querying the status of the upload.
-      request.next_chunk(http)
+      request.next_chunk(http=http)
     except HttpError, e:
       expected = {
           'Content-Range': 'bytes */*',
@@ -634,13 +641,13 @@
 
   def test_next_successful_none_on_no_next_page_token(self):
     self.http = HttpMock(datafile('tasks.json'), {'status': '200'})
-    tasks = build('tasks', 'v1', self.http)
+    tasks = build('tasks', 'v1', http=self.http)
     request = tasks.tasklists().list()
     self.assertEqual(None, tasks.tasklists().list_next(request, {}))
 
   def test_next_successful_with_next_page_token(self):
     self.http = HttpMock(datafile('tasks.json'), {'status': '200'})
-    tasks = build('tasks', 'v1', self.http)
+    tasks = build('tasks', 'v1', http=self.http)
     request = tasks.tasklists().list()
     next_request = tasks.tasklists().list_next(
         request, {'nextPageToken': '123abc'})
@@ -650,7 +657,7 @@
 
   def test_next_with_method_with_no_properties(self):
     self.http = HttpMock(datafile('latitude.json'), {'status': '200'})
-    service = build('latitude', 'v1', self.http)
+    service = build('latitude', 'v1', http=self.http)
     request = service.currentLocation().get()
 
 
@@ -658,7 +665,7 @@
 
   def test_get_media(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     request = zoo.animals().get_media(name='Lion')
 
     parsed = urlparse.urlparse(request.uri)
@@ -669,7 +676,7 @@
     http = HttpMockSequence([
       ({'status': '200'}, 'standing in for media'),
       ])
-    response = request.execute(http)
+    response = request.execute(http=http)
     self.assertEqual('standing in for media', response)
 
 
diff --git a/tests/test_errors.py b/tests/test_errors.py
index 25e5d2c..c45ce35 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -59,7 +59,7 @@
     resp, content = fake_response(JSON_ERROR_CONTENT,
         {'status':'400', 'content-type': 'application/json'},
         reason='Failed')
-    error = HttpError(resp, content, 'http://example.org')
+    error = HttpError(resp, content, uri='http://example.org')
     self.assertEqual(str(error), '<HttpError 400 when requesting http://example.org returned "country is required">')
 
   def test_bad_json_body(self):
@@ -75,7 +75,7 @@
     resp, content = fake_response('{',
         {'status':'400', 'content-type': 'application/json'},
         reason='Failure')
-    error = HttpError(resp, content, 'http://example.org')
+    error = HttpError(resp, content, uri='http://example.org')
     self.assertEqual(str(error), '<HttpError 400 when requesting http://example.org returned "Failure">')
 
   def test_missing_message_json_body(self):
diff --git a/tests/test_http.py b/tests/test_http.py
index 9387e3a..45cdaf5 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -140,7 +140,7 @@
     self.assertEqual('PNG', new_upload.getbytes(1, 3))
 
   def test_media_inmemory_upload(self):
-    media = MediaInMemoryUpload('abcdef', 'text/plain', chunksize=10,
+    media = MediaInMemoryUpload('abcdef', mimetype='text/plain', chunksize=10,
                                 resumable=True)
     self.assertEqual('text/plain', media.mimetype())
     self.assertEqual(10, media.chunksize())
@@ -149,7 +149,7 @@
     self.assertEqual(6, media.size())
 
   def test_media_inmemory_upload_json_roundtrip(self):
-    media = MediaInMemoryUpload(os.urandom(64), 'text/plain', chunksize=10,
+    media = MediaInMemoryUpload(os.urandom(64), mimetype='text/plain', chunksize=10,
                                 resumable=True)
     data = media.to_json()
     newmedia = MediaInMemoryUpload.new_from_json(data)
@@ -261,7 +261,7 @@
 
   def setUp(self):
     http = HttpMock(datafile('zoo.json'), {'status': '200'})
-    zoo = build('zoo', 'v1', http)
+    zoo = build('zoo', 'v1', http=http)
     self.request = zoo.animals().get_media(name='Lion')
     self.fd = StringIO.StringIO()
 
@@ -587,7 +587,7 @@
         'content-type': 'multipart/mixed; boundary="batch_foobarbaz"'},
        BATCH_RESPONSE),
       ])
-    batch.execute(http)
+    batch.execute(http=http)
     self.assertEqual({'foo': 42}, callbacks.responses['1'])
     self.assertEqual(None, callbacks.exceptions['1'])
     self.assertEqual({'baz': 'qux'}, callbacks.responses['2'])
@@ -604,7 +604,7 @@
         'echo_request_body'),
       ])
     try:
-      batch.execute(http)
+      batch.execute(http=http)
       self.fail('Should raise exception')
     except BatchError, e:
       boundary, _ = e.content.split(None, 1)
@@ -642,7 +642,7 @@
 
     batch.add(self.request1, callback=callbacks.f)
     batch.add(self.request2, callback=callbacks.f)
-    batch.execute(http)
+    batch.execute(http=http)
 
     self.assertEqual({'foo': 42}, callbacks.responses['1'])
     self.assertEqual(None, callbacks.exceptions['1'])
@@ -684,7 +684,7 @@
 
     batch.add(self.request1, callback=callbacks.f)
     batch.add(self.request2, callback=callbacks.f)
-    batch.execute(http)
+    batch.execute(http=http)
 
     self.assertEqual(None, callbacks.responses['1'])
     self.assertEqual(401, callbacks.exceptions['1'].resp.status)
@@ -704,7 +704,7 @@
         'content-type': 'multipart/mixed; boundary="batch_foobarbaz"'},
        BATCH_RESPONSE),
       ])
-    batch.execute(http)
+    batch.execute(http=http)
     self.assertEqual({'foo': 42}, callbacks.responses['1'])
     self.assertEqual({'baz': 'qux'}, callbacks.responses['2'])
 
@@ -719,7 +719,7 @@
         'content-type': 'multipart/mixed; boundary="batch_foobarbaz"'},
        BATCH_ERROR_RESPONSE),
       ])
-    batch.execute(http)
+    batch.execute(http=http)
     self.assertEqual({'foo': 42}, callbacks.responses['1'])
     expected = ('<HttpError 403 when requesting '
         'https://www.googleapis.com/someapi/v1/collection/?foo=bar returned '
diff --git a/tests/test_oauth2client.py b/tests/test_oauth2client.py
index a618674..be94fa1 100644
--- a/tests/test_oauth2client.py
+++ b/tests/test_oauth2client.py
@@ -55,13 +55,16 @@
 
 DATA_DIR = os.path.join(os.path.dirname(__file__), 'data')
 
+
 def datafile(filename):
   return os.path.join(DATA_DIR, filename)
 
+
 def load_and_cache(existing_file, fakename, cache_mock):
   client_type, client_info = _loadfile(datafile(existing_file))
   cache_mock.cache[fakename] = {client_type: client_info}
 
+
 class CacheMock(object):
     def __init__(self):
       self.cache = {}
@@ -195,7 +198,7 @@
   def setUp(self):
     user_agent = "fun/2.0"
     self.credentials = self.AssertionCredentialsTestImpl(self.assertion_type,
-        user_agent)
+        user_agent=user_agent)
 
   def test_assertion_body(self):
     body = urlparse.parse_qs(self.credentials._generate_refresh_request_body())
@@ -230,6 +233,7 @@
 
     self.assertRaises(VerifyJwtTokenError, _extract_id_token, jwt)
 
+
 class OAuth2WebServerFlowTest(unittest.TestCase):
 
   def setUp(self):
@@ -237,18 +241,19 @@
         client_id='client_id+1',
         client_secret='secret+1',
         scope='foo',
+        redirect_uri=OOB_CALLBACK_URN,
         user_agent='unittest-sample/1.0',
         )
 
   def test_construct_authorize_url(self):
-    authorize_url = self.flow.step1_get_authorize_url('OOB_CALLBACK_URN')
+    authorize_url = self.flow.step1_get_authorize_url()
 
     parsed = urlparse.urlparse(authorize_url)
     q = parse_qs(parsed[4])
     self.assertEqual('client_id+1', q['client_id'][0])
     self.assertEqual('code', q['response_type'][0])
     self.assertEqual('foo', q['scope'][0])
-    self.assertEqual('OOB_CALLBACK_URN', q['redirect_uri'][0])
+    self.assertEqual(OOB_CALLBACK_URN, q['redirect_uri'][0])
     self.assertEqual('offline', q['access_type'][0])
 
   def test_override_flow_access_type(self):
@@ -257,17 +262,18 @@
         client_id='client_id+1',
         client_secret='secret+1',
         scope='foo',
+        redirect_uri=OOB_CALLBACK_URN,
         user_agent='unittest-sample/1.0',
         access_type='online'
         )
-    authorize_url = flow.step1_get_authorize_url('OOB_CALLBACK_URN')
+    authorize_url = flow.step1_get_authorize_url()
 
     parsed = urlparse.urlparse(authorize_url)
     q = parse_qs(parsed[4])
     self.assertEqual('client_id+1', q['client_id'][0])
     self.assertEqual('code', q['response_type'][0])
     self.assertEqual('foo', q['scope'][0])
-    self.assertEqual('OOB_CALLBACK_URN', q['redirect_uri'][0])
+    self.assertEqual(OOB_CALLBACK_URN, q['redirect_uri'][0])
     self.assertEqual('online', q['access_type'][0])
 
   def test_exchange_failure(self):
@@ -276,7 +282,7 @@
       ])
 
     try:
-      credentials = self.flow.step2_exchange('some random code', http)
+      credentials = self.flow.step2_exchange('some random code', http=http)
       self.fail("should raise exception if exchange doesn't get 200")
     except FlowExchangeError:
       pass
@@ -287,7 +293,7 @@
     ])
 
     try:
-      credentials = self.flow.step2_exchange('some random code', http)
+      credentials = self.flow.step2_exchange('some random code', http=http)
       self.fail("should raise exception if exchange doesn't get 200")
     except FlowExchangeError, e:
       self.assertEquals('invalid_request', str(e))
@@ -305,7 +311,7 @@
       ])
 
     try:
-      credentials = self.flow.step2_exchange('some random code', http)
+      credentials = self.flow.step2_exchange('some random code', http=http)
       self.fail("should raise exception if exchange doesn't get 200")
     except FlowExchangeError, e:
       pass
@@ -318,7 +324,7 @@
        "refresh_token":"8xLOxBtZp8" }"""),
       ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertEqual('SlAV32hkKG', credentials.access_token)
     self.assertNotEqual(None, credentials.token_expiry)
     self.assertEqual('8xLOxBtZp8', credentials.refresh_token)
@@ -328,7 +334,7 @@
       ({'status': '200'}, "access_token=SlAV32hkKG&expires_in=3600"),
     ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertEqual('SlAV32hkKG', credentials.access_token)
     self.assertNotEqual(None, credentials.token_expiry)
 
@@ -339,7 +345,7 @@
       ({'status': '200'}, "access_token=SlAV32hkKG&expires=3600"),
     ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertNotEqual(None, credentials.token_expiry)
 
   def test_exchange_no_expires_in(self):
@@ -348,7 +354,7 @@
        "refresh_token":"8xLOxBtZp8" }"""),
       ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertEqual(None, credentials.token_expiry)
 
   def test_urlencoded_exchange_no_expires_in(self):
@@ -358,7 +364,7 @@
       ({'status': '200'}, "access_token=SlAV32hkKG"),
     ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertEqual(None, credentials.token_expiry)
 
   def test_exchange_fails_if_no_code(self):
@@ -369,7 +375,7 @@
 
     code = {'error': 'thou shall not pass'}
     try:
-      credentials = self.flow.step2_exchange(code, http)
+      credentials = self.flow.step2_exchange(code, http=http)
       self.fail('should raise exception if no code in dictionary.')
     except FlowExchangeError, e:
       self.assertTrue('shall not pass' in str(e))
@@ -382,7 +388,7 @@
       ])
 
     self.assertRaises(VerifyJwtTokenError, self.flow.step2_exchange,
-      'some random code', http)
+      'some random code', http=http)
 
   def test_exchange_id_token_fail(self):
     body = {'foo': 'bar'}
@@ -396,19 +402,21 @@
        "id_token": "%s"}""" % jwt),
       ])
 
-    credentials = self.flow.step2_exchange('some random code', http)
+    credentials = self.flow.step2_exchange('some random code', http=http)
     self.assertEqual(credentials.id_token, body)
 
-class FlowFromCachedClientsecrets(unittest.TestCase):  
+
+class FlowFromCachedClientsecrets(unittest.TestCase):
 
   def test_flow_from_clientsecrets_cached(self):
     cache_mock = CacheMock()
     load_and_cache('client_secrets.json', 'some_secrets', cache_mock)
-    
-    # flow_from_clientsecrets(filename, scope, message=None, cache=None)
-    flow = flow_from_clientsecrets('some_secrets', '', cache=cache_mock)
+
+    flow = flow_from_clientsecrets(
+        'some_secrets', '', redirect_uri='oob', cache=cache_mock)
     self.assertEquals('foo_client_secret', flow.client_secret)
 
+
 class CredentialsFromCodeTests(unittest.TestCase):
   def setUp(self):
     self.client_id = 'client_id_abc'
@@ -424,8 +432,8 @@
        "expires_in":3600 }"""),
     ])
     credentials = credentials_from_code(self.client_id, self.client_secret,
-                                    self.scope, self.code, self.redirect_uri,
-                                    http)
+        self.scope, self.code, redirect_uri=self.redirect_uri,
+        http=http)
     self.assertEquals(credentials.access_token, 'asdfghjkl')
     self.assertNotEqual(None, credentials.token_expiry)
 
@@ -436,13 +444,12 @@
 
     try:
       credentials = credentials_from_code(self.client_id, self.client_secret,
-                                      self.scope, self.code, self.redirect_uri,
-                                      http)
+          self.scope, self.code, redirect_uri=self.redirect_uri,
+          http=http)
       self.fail("should raise exception if exchange doesn't get 200")
     except FlowExchangeError:
       pass
 
-
   def test_exchange_code_and_file_for_token(self):
     http = HttpMockSequence([
       ({'status': '200'},
@@ -481,7 +488,6 @@
       pass
 
 
-
 class MemoryCacheTests(unittest.TestCase):
 
   def test_get_set_delete(self):
diff --git a/tests/test_oauth2client_appengine.py b/tests/test_oauth2client_appengine.py
index 58f3e55..6774abd 100644
--- a/tests/test_oauth2client_appengine.py
+++ b/tests/test_oauth2client_appengine.py
@@ -55,7 +55,6 @@
 from oauth2client.appengine import CredentialsModel
 from oauth2client.appengine import FlowProperty
 from oauth2client.appengine import OAuth2Decorator
-from oauth2client.appengine import OAuth2Handler
 from oauth2client.appengine import StorageByKeyName
 from oauth2client.appengine import oauth2decorator_from_clientsecrets
 from oauth2client.client import AccessTokenRefreshError
@@ -200,7 +199,8 @@
 
   def test_flow_get_put(self):
     instance = TestFlowModel(
-        flow=flow_from_clientsecrets(datafile('client_secrets.json'), 'foo'),
+        flow=flow_from_clientsecrets(datafile('client_secrets.json'), 'foo',
+                                     redirect_uri='oob'),
         key_name='foo'
         )
     instance.put()
@@ -276,6 +276,14 @@
     self.assertEqual(None, credentials)
     self.assertEqual(None, memcache.get('foo'))
 
+class MockRequest(object):
+  url = 'https://example.org'
+
+  def relative_url(self, rel):
+    return self.url + rel
+
+class MockRequestHandler(object):
+  request = MockRequest()
 
 class DecoratorTests(unittest.TestCase):
 
@@ -312,7 +320,7 @@
 
 
     application = webapp2.WSGIApplication([
-        ('/oauth2callback', OAuth2Handler),
+        ('/oauth2callback', self.decorator.callback_handler()),
         ('/foo_path', TestRequiredHandler),
         webapp2.Route(r'/bar_path/<year:\d{4}>/<month:\d{2}>',
           handler=TestAwareHandler, name='bar')],
@@ -441,6 +449,11 @@
         scope=['foo_scope', 'bar_scope'],
         access_type='offline',
         approval_prompt='force')
+    request_handler = MockRequestHandler()
+    decorator._create_flow(request_handler)
+
+    self.assertEqual('https://example.org/oauth2callback',
+                     decorator.flow.redirect_uri)
     self.assertEqual('offline', decorator.flow.params['access_type'])
     self.assertEqual('force', decorator.flow.params['approval_prompt'])
     self.assertEqual('foo_user_agent', decorator.flow.user_agent)
diff --git a/tests/test_oauth2client_jwt.py b/tests/test_oauth2client_jwt.py
index 65a3410..11162be 100644
--- a/tests/test_oauth2client_jwt.py
+++ b/tests/test_oauth2client_jwt.py
@@ -114,7 +114,7 @@
       ])
 
     contents = verify_id_token(jwt,
-        'some_audience_address@testing.gserviceaccount.com', http)
+        'some_audience_address@testing.gserviceaccount.com', http=http)
     self.assertEqual('billy bob', contents['user'])
     self.assertEqual('data', contents['metadata']['meta'])
 
@@ -126,7 +126,7 @@
       ])
 
     self.assertRaises(VerifyJwtTokenError, verify_id_token, jwt,
-        'some_audience_address@testing.gserviceaccount.com', http)
+        'some_audience_address@testing.gserviceaccount.com', http=http)
 
   def test_verify_id_token_bad_tokens(self):
     private_key = datafile('privatekey.p12')