diff --git a/lib/rails_big_brother.rb b/lib/rails_big_brother.rb
index 62315da..cc4e37d 100644
--- a/lib/rails_big_brother.rb
+++ b/lib/rails_big_brother.rb
@@ -1,5 +1,48 @@
 require "rails_big_brother/version"
+require "rails_big_brother/controller"
+require "rails_big_brother/model"
 
 module RailsBigBrother
-  # Your code goes here...
+  def user=(value)
+    store[:user] = value
+  end
+
+  def user
+    store[:user]
+  end
+
+  def controller_info=(value)
+    store[:controller_info] = value
+  end
+
+  def controller_info
+    store[:controller_info]
+  end
+
+  def controller_info_string
+    case controller_info
+    when Array
+      controller_info.join(',')
+    when Hash
+      controller_info.map { |k,v| "#{k}:#{v}" }.join(',')
+    else
+      controller_info
+    end
+  end
+
+  private
+
+  def store
+    Thread.current[:big_brother_log] ||= {}
+  end
+
+  extend self
+end
+
+ActiveSupport.on_load(:active_record) do
+  include RailsBigBrother::Model
+end
+
+ActiveSupport.on_load(:action_controller) do
+  include RailsBigBrother::Controller
 end
diff --git a/lib/rails_big_brother/controller.rb b/lib/rails_big_brother/controller.rb
new file mode 100644
index 0000000..e8ce14b
--- /dev/null
+++ b/lib/rails_big_brother/controller.rb
@@ -0,0 +1,27 @@
+module RailsBigBrother
+  module Controller
+    def self.included(base)
+      base.before_filter :set_log_current_user, :set_log_infos
+    end
+
+    protected
+
+    def big_brother_user
+      nil
+    end
+
+    def big_brother_infos
+      {}
+    end
+
+    private
+
+    def set_log_current_user
+      ::RailsBigBrother.user = big_brother_user
+    end
+
+    def set_log_infos
+      ::RailsBigBrother.controller_info = big_brother_infos
+    end
+  end
+end
diff --git a/lib/rails_big_brother/model.rb b/lib/rails_big_brother/model.rb
new file mode 100644
index 0000000..1f4d778
--- /dev/null
+++ b/lib/rails_big_brother/model.rb
@@ -0,0 +1,53 @@
+module RailsBigBrother
+  module Model
+    def self.included(base)
+      base.send :extend, ClassMethods
+    end
+
+    module ClassMethods
+      def big_brother_watch(options = {})
+        send :include, InstanceMethods
+
+        class_attribute :big_brother_options
+        self.big_brother_options = {}
+
+        [:ignore, :only].each do |k|
+          self.big_brother_options[k] = [options[k]].flatten.compact.map(&:to_s) if options.has_key?(k)
+        end
+
+        after_create :log_create if !options[:on] || options[:on].include?(:create)
+        before_update :log_update if !options[:on] || options[:on].include?(:update)
+        after_destroy :log_destroy if !options[:on] || options[:on].include?(:destroy)
+      end
+    end
+
+    module InstanceMethods
+      private
+
+      def log_create
+        big_brother_log 'create'
+      end
+
+      def log_update
+        changed_fields = self.changed
+        changed_fields = changed_fields - self.class.big_brother_options[:ignore] if self.class.big_brother_options.has_key?(:ignore)
+        changed_fields = changed_fields & self.class.big_brother_options[:only] if self.class.big_brother_options.has_key?(:only)
+
+        unless changed_fields.empty?
+          big_brother_log 'update', changed_fields.join(',')
+        end
+      end
+
+      def log_destroy
+        big_brother_log 'destroy', to_s
+      end
+
+      def big_brother_log(action, *args)
+        # TODO RailsBigBrother.format, RailsBigBrother.separator
+        Rails.logger.info "big_brother;#{RailsBigBrother.user};" <<
+          "#{RailsBigBrother.controller_info_string};" <<
+          "#{self.class.name};#{self.to_param};#{action};#{args.join(';')}"
+      end
+    end
+  end
+end