diff --git a/Vagrantfile b/Vagrantfile
index ee5fb04c..a1cb6bcb 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -10,9 +10,6 @@ require_relative 'lib/configurator'
 VERSION='0.6.0-a1-SNAPSHOT'
 
 
-# load File.dirname(__FILE__) + '/lib/utility.rb'
-# load File.dirname(__FILE__) + '/lib/settings_processor.rb'
-
 $logger = get_logger()
 
 
@@ -37,26 +34,43 @@ require_version(settings['teracy-dev']['require_version'])
 
 
 # preload-ext list here
-preload_ext_paths = settings["vagrant"]["preload_extension_paths"] ||= []
+extension_paths = settings["vagrant"]["extension_paths"] ||= []
+
 
+$logger.debug("load extensions")
 
-preload_ext_paths.each do |path|
+extension_paths.each do |path|
   load_file_path(path)
 end
 
 
+# for example, extension can register hooks
+=begin
+
+my_before_configure = Proc.new do |node_config, node|
+  $logger.debug("my_before_configure")
+end
+
+my_after_configure = Proc.new do |node_config, node|
+  $logger.debug("my_after_configure")
+end
+
+register_before_configure_hook(&my_before_configure)
+register_after_configure_hook(&my_after_configure)
+
+=end
+
+
 Vagrant.configure("2") do |config|
+
   settings["nodes"].each do |node_config|
-    $logger.debug("node_config: #{node_config}")
     primary = node_config["primary"] ||= false
     autostart = node_config["autostart"] === false ? false : true
+    # NOTE: the next line is async
     config.vm.define node_config["name"], primary: primary, autostart: autostart do |node|
+      $logger.debug("node_config: #{node_config}")
       configure(node_config, node)
     end
   end
-  # postload-ext list here
-  postload_ext_paths = settings["vagrant"]["postload_extension_paths"] ||= []
-  postload_ext_paths.each do |path|
-    load_file_path(path)
-  end
+
 end
diff --git a/config_default.yaml b/config_default.yaml
index efd22e1a..991c56ba 100644
--- a/config_default.yaml
+++ b/config_default.yaml
@@ -34,10 +34,9 @@ vagrant:
       options:
         manage_host: true
         manage_guest: true
-  # usually defined from workspace/dev-setup/
-  preload_extension_paths:
-  postload_extension_paths:
-  config_paths:
+  # usually defined on workspace/dev-setup/config_default.yaml
+  extension_file_paths:
+  config_file_paths:
 
 
 # teracy-dev related settings
diff --git a/lib/configurator.rb b/lib/configurator.rb
index ff46d090..84b37d4c 100644
--- a/lib/configurator.rb
+++ b/lib/configurator.rb
@@ -61,7 +61,42 @@ def _configure_providers(providers_config, node)
 end
 
 
+$before_hooks = []
+$after_hooks = []
+
+def _run_before_configure_hooks(node_config, node)
+  $logger.debug("_run_before_configure_hooks")
+  $before_hooks.each do |block|
+    block.call(node_config, node)
+  end
+end
+
+
+def _run_after_configure_hooks(node_config, node)
+  $logger.debug("_run_after_configure_hooks")
+  $after_hooks.each do |block|
+    block.call(node_config, node)
+  end
+end
+
+
+def register_before_configure_hook(&block)
+  $before_hooks << block
+  $logger.debug("$before_hooks: #{$before_hooks}")
+end
+
+
+def register_after_configure_hook(&block)
+  $after_hooks << block
+  $logger.debug("$after_hooks: #{$after_hooks}")
+end
+
+
+
 def configure(node_config, node)
+  # hooks callback
+  _run_before_configure_hooks(node_config, node)
+
   _configure_vm(node_config["vm"], node)
   _configure_ssh(node_config["ssh"], node)
   _configure_winrm(node_config["winrm"], node)
@@ -71,4 +106,7 @@ def configure(node_config, node)
   _configure_networks(node_config["networks"], node)
   _configure_sync_folders(node_config["synced-folders"], node)
   _configure_provisioners(node_config["providers"], node)
+
+  # hooks calback
+  _run_after_configure_hooks(node_config, node)
 end