diff --git a/googleapiclient/sample_tools.py b/googleapiclient/sample_tools.py
index 4dd6935..69f698e 100644
--- a/googleapiclient/sample_tools.py
+++ b/googleapiclient/sample_tools.py
@@ -31,7 +31,7 @@
 from oauth2client import tools
 
 
-def init(argv, name, version, doc, filename, scope=None, parents=[]):
+def init(argv, name, version, doc, filename, scope=None, parents=[], discovery_filename=None):
   """A common initialization routine for samples.
 
   Many of the sample applications do the same initialization, which has now
@@ -49,6 +49,7 @@
     file: string, filename of the application. Usually set to __file__.
     parents: list of argparse.ArgumentParser, additional command-line flags.
     scope: string, The OAuth scope used.
+    discovery_filename: string, name of local discovery file (JSON). Use when discovery doc not available via URL.
 
   Returns:
     A tuple of (service, flags), where service is the service object and flags
@@ -88,6 +89,14 @@
     credentials = tools.run_flow(flow, storage, flags)
   http = credentials.authorize(http = httplib2.Http())
 
-  # Construct a service object via the discovery service.
-  service = discovery.build(name, version, http=http)
+  if discovery_filename is None:
+    # Construct a service object via the discovery service.
+    service = discovery.build(name, version, http=http)
+  else:
+    # Construct a service object using a local discovery document file.
+	with open(discovery_filename) as discovery_file:
+	  service = discovery.build_from_document(
+		  discovery_file.read(),
+		  base='https://www.googleapis.com/',
+		  http=http)
   return (service, flags)