diff --git a/oauth2client/clientsecrets.py b/oauth2client/clientsecrets.py
new file mode 100644
index 0000000..da48be7
--- /dev/null
+++ b/oauth2client/clientsecrets.py
@@ -0,0 +1,113 @@
+# Copyright (C) 2011 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.
+
+"""Utilities for reading OAuth 2.0 client secret files.
+
+A client_secrets.json file contains all the information needed to interact with
+an OAuth 2.0 protected service.
+"""
+
+__author__ = 'jcgregorio@google.com (Joe Gregorio)'
+
+
+try: # pragma: no cover
+  import simplejson
+except ImportError: # pragma: no cover
+  try:
+    # Try to import from django, should work on App Engine
+    from django.utils import simplejson
+  except ImportError:
+    # Should work for Python2.6 and higher.
+    import json as simplejson
+
+# Properties that make a client_secrets.json file valid.
+TYPE_WEB = 'web'
+TYPE_INSTALLED = 'installed'
+
+VALID_CLIENT = {
+    TYPE_WEB: {
+        'required': [
+            'client_id',
+            'client_secret',
+            'redirect_uris',
+            'auth_uri',
+            'token_uri'],
+        'string': [
+            'client_id',
+            'client_secret'
+            ]
+        },
+    TYPE_INSTALLED: {
+        'required': [
+            'client_id',
+            'client_secret',
+            'redirect_uris',
+            'auth_uri',
+            'token_uri'],
+        'string': [
+            'client_id',
+            'client_secret'
+            ]
+      }
+    }
+
+class Error(Exception):
+  """Base error for this module."""
+  pass
+
+
+class InvalidClientSecretsError(Error):
+  """Format of ClientSecrets file is invalid."""
+  pass
+
+
+def _validate_clientsecrets(obj):
+  if obj is None or len(obj) != 1:
+    raise InvalidClientSecretsError('Invalid file format.')
+  client_type = obj.keys()[0]
+  if client_type not in VALID_CLIENT.keys():
+    raise InvalidClientSecretsError('Unknown client type: %s.' % client_type)
+  client_info = obj[client_type]
+  for prop_name in VALID_CLIENT[client_type]['required']:
+    if prop_name not in client_info:
+      raise InvalidClientSecretsError(
+        'Missing property "%s" in a client type of "%s".' % (prop_name,
+                                                           client_type))
+  for prop_name in VALID_CLIENT[client_type]['string']:
+    if client_info[prop_name].startswith('[['):
+      raise InvalidClientSecretsError(
+        'Property "%s" is not configured.' % prop_name)
+  return client_type, client_info
+
+
+def load(fp):
+  obj = simplejson.load(fp)
+  return _validate_clientsecrets(obj)
+
+
+def loads(s):
+  obj = simplejson.loads(s)
+  return _validate_clientsecrets(obj)
+
+
+def loadfile(filename):
+  try:
+    fp = file(filename, 'r')
+    try:
+      obj = simplejson.load(fp)
+    finally:
+      fp.close()
+  except IOError:
+    raise InvalidClientSecretsError('File not found: "%s"' % filename)
+  return _validate_clientsecrets(obj)