diff --git a/lib/sift/client.rb b/lib/sift/client.rb
index 7054b2a..2978b8b 100644
--- a/lib/sift/client.rb
+++ b/lib/sift/client.rb
@@ -92,6 +92,10 @@ def self.build_auth_header(api_key)
       { "Authorization" => "Basic #{Base64.encode64(api_key)}" }
     end
 
+    def self.user_agent
+      "sift-ruby/#{VERSION}"
+    end
+
     # Constructor
     #
     # ==== Parameters:
diff --git a/lib/sift/router.rb b/lib/sift/router.rb
index da826d8..69e4015 100644
--- a/lib/sift/router.rb
+++ b/lib/sift/router.rb
@@ -8,11 +8,13 @@ class Router
     class << self
       def get(path, options = {})
         serialize_body(options)
+        add_default_headers(options)
         wrap_response(super(path, options))
       end
 
       def post(path, options = {})
         serialize_body(options)
+        add_default_headers(options)
         wrap_response(super(path, options))
       end
 
@@ -20,6 +22,12 @@ def serialize_body(options)
         options[:body] = MultiJson.dump(options[:body]) if options[:body]
       end
 
+      def add_default_headers(options)
+        options[:headers] = {
+          "User-Agent" => Sift::Client.user_agent
+        }.merge(options[:headers] || {})
+      end
+
       def wrap_response(response)
         Response.new(
           response.body,
diff --git a/lib/sift/version.rb b/lib/sift/version.rb
index b3658ba..4b4a138 100644
--- a/lib/sift/version.rb
+++ b/lib/sift/version.rb
@@ -1,4 +1,4 @@
 module Sift
-  VERSION = "2.0.0.0"
+  VERSION = "2.1.0.0"
   API_VERSION = "204"
 end