add user-agent for php
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index 48c0097..8c438e4 100755
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -60,7 +60,10 @@
       }
       unset($opts['update_metadata']);
     }
-         
+    $package_config = json_decode(
+        file_get_contents(dirname(__FILE__) . '/../../composer.json'), true);
+    $opts['grpc.primary_user_agent'] =
+        'grpc-php/' . $package_config['version'];
     $this->channel = new Channel($hostname, $opts);
   }