diff --git a/Gemfile.lock b/Gemfile.lock
index a776dc4..82e43ea 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    ruby-pardot (1.0.2)
+    ruby-pardot (1.1.0)
       crack
       httparty
 
@@ -15,7 +15,7 @@ GEM
     httparty (0.13.1)
       json (~> 1.8)
       multi_xml (>= 0.5.2)
-    json (1.8.1)
+    json (1.8.3)
     multi_xml (0.5.5)
     rspec (2.5.0)
       rspec-core (~> 2.5.0)
@@ -25,13 +25,16 @@ GEM
     rspec-expectations (2.5.0)
       diff-lcs (~> 1.1.2)
     rspec-mocks (2.5.0)
-    safe_yaml (1.0.3)
+    safe_yaml (1.0.4)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  bundler (>= 1.0.0)
+  bundler (>= 1.10)
   fakeweb
   rspec
   ruby-pardot!
+
+BUNDLED WITH
+   1.11.2
diff --git a/lib/pardot/authentication.rb b/lib/pardot/authentication.rb
index 84821b8..7919285 100644
--- a/lib/pardot/authentication.rb
+++ b/lib/pardot/authentication.rb
@@ -3,6 +3,7 @@ module Authentication
     
     def authenticate
       resp = post "login", nil, :email => @email, :password => @password, :user_key => @user_key
+      update_version(resp["version"]) if resp && resp["version"]
       @api_key = resp && resp["api_key"]
     end
     
@@ -14,6 +15,15 @@ def reauthenticate
       @api_key = nil
       authenticate
     end
-    
+
+    private
+
+    def update_version version
+      if version.is_a? Array
+        version = version.last
+      end
+      @version = version if version.to_i > 3
+    end
+
   end
 end
diff --git a/lib/pardot/client.rb b/lib/pardot/client.rb
index 914dbff..36e9745 100644
--- a/lib/pardot/client.rb
+++ b/lib/pardot/client.rb
@@ -20,16 +20,16 @@ class Client
     include Objects::Visits
     include Objects::VisitorActivities
 
-    attr_accessor :email, :password, :user_key, :api_key, :format
+    attr_accessor :email, :password, :user_key, :api_key, :version, :format
 
-    def initialize email, password, user_key
+    def initialize email, password, user_key, version = 3
       @email = email
       @password = password
       @user_key = user_key
+      @version = version
 
       @format = "simple"
     end
 
-
   end
 end
diff --git a/lib/pardot/http.rb b/lib/pardot/http.rb
index e0de31a..0dd33e9 100644
--- a/lib/pardot/http.rb
+++ b/lib/pardot/http.rb
@@ -58,8 +58,8 @@ def check_response http_response
       rsp
     end
     
-    def fullpath object, path, version = 3
-      full = File.join("/api", object, "version", version.to_s)
+    def fullpath object, path
+      full = File.join("/api", object, "version", @version.to_s)
       unless path.nil?
         full = File.join(full, path)
       end
diff --git a/lib/pardot/objects/prospects.rb b/lib/pardot/objects/prospects.rb
index 704eb9a..583f3d2 100644
--- a/lib/pardot/objects/prospects.rb
+++ b/lib/pardot/objects/prospects.rb
@@ -26,10 +26,22 @@ def assign_by_id id, params
           post "/do/assign/id/#{id}", params
         end
         
+        def assign_by_fid fid, params
+          post "/do/assign/fid/#{fid}", params
+        end
+        
         def create email, params = {}
           post "/do/create/email/#{email}", params
         end
         
+        def delete_by_id id, params = {}
+          post "/do/delete/id/#{id}", params
+        end
+        
+        def delete_by_fid fid, params = {}
+          post "/do/delete/fid/#{fid}", params
+        end
+        
         def read_by_email email, params = {}
           post "/do/read/email/#{email}", params
         end
@@ -38,6 +50,22 @@ def read_by_id id, params = {}
           post "/do/read/id/#{id}", params
         end
         
+        def read_by_fid fid, params = {}
+          post "/do/read/fid/#{fid}", params
+        end
+        
+        def unassign_by_email email, params = {}
+          post "/do/unassign/email/#{email}", params
+        end
+        
+        def unassign_by_id id, params = {}
+          post "/do/unassign/id/#{id}", params
+        end
+        
+        def unassign_by_fid fid, params = {}
+          post "/do/unassign/fid/#{fid}", params
+        end
+        
         def update_by_email email, params = {}
           post "/do/update/email/#{email}", params
         end
@@ -46,6 +74,10 @@ def update_by_id id, params = {}
           post "/do/update/id/#{id}", params
         end
         
+        def update_by_fid fid, params = {}
+          post "/do/update/fid/#{fid}", params
+        end
+        
         def upsert_by_email email, params = {}
           post "/do/upsert/email/#{email}", params
         end
@@ -54,6 +86,10 @@ def upsert_by_id id, params = {}
           post "/do/upsert/id/#{id}", params
         end
         
+        def upsert_by_fid fid, params = {}
+          post "/do/upsert/fid/#{fid}", params
+        end
+        
         protected
         
         def get path, params = {}, result = "prospect"
diff --git a/lib/pardot/version.rb b/lib/pardot/version.rb
index d71de34..e305cb3 100644
--- a/lib/pardot/version.rb
+++ b/lib/pardot/version.rb
@@ -1,3 +1,3 @@
 module Pardot
-  VERSION = "1.0.2"
+  VERSION = "1.1.0"
 end
diff --git a/ruby-pardot.gemspec b/ruby-pardot.gemspec
index 979b4b9..f710b11 100644
--- a/ruby-pardot.gemspec
+++ b/ruby-pardot.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.add_dependency "crack"
   s.add_dependency "httparty"
 
-  s.add_development_dependency "bundler", ">= 1.0.0"
+  s.add_development_dependency "bundler", ">= 1.10"
   s.add_development_dependency "rspec"
   s.add_development_dependency "fakeweb"
 
diff --git a/spec/pardot/authentication_spec.rb b/spec/pardot/authentication_spec.rb
index 845c265..ee0af8d 100644
--- a/spec/pardot/authentication_spec.rb
+++ b/spec/pardot/authentication_spec.rb
@@ -32,6 +32,45 @@ def authenticate
       authenticate
       @client.authenticated?.should == true
     end
+
+    it "should use version 3" do
+      authenticate
+      @client.version.to_i.should == 3
+    end
+    
+  end
+
+  describe "authenticateV4" do
+    
+    before do
+      @client = create_client
+      
+      fake_post "/api/login/version/3?email=user%40test.com&password=foo&user_key=bar",
+                %(<?xml version="1.0" encoding="UTF-8"?>\n<rsp stat="ok" version="1.0">\n   <api_key>my_api_key</api_key>\n<version>4</version>\n</rsp>\n)
+    end
+    
+    def authenticate
+      @client.authenticate
+    end
+    
+    it "should return the api key" do
+      authenticate.should == "my_api_key"
+    end
+    
+    it "should set the api key" do
+      authenticate
+      @client.api_key.should == "my_api_key"
+    end
+    
+    it "should make authenticated? true" do
+      authenticate
+      @client.authenticated?.should == true
+    end
+
+    it "should use version 4" do
+      authenticate
+      @client.version.to_i.should == 4
+    end
     
   end
   
diff --git a/spec/pardot/client_spec.rb b/spec/pardot/client_spec.rb
new file mode 100644
index 0000000..324f2e4
--- /dev/null
+++ b/spec/pardot/client_spec.rb
@@ -0,0 +1,28 @@
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
+
+describe Pardot::Client do
+  
+  def create_client
+    @client = Pardot::Client.new "user@test.com", "foo", "bar"
+  end
+  
+  describe "client" do
+    after do
+      @client.email.should == "user@test.com"
+      @client.password.should == "password"
+      @client.user_key.should == "user_key"
+      @client.format.should == "simple"
+    end
+
+    it "should set variables without version" do
+      @client = Pardot::Client.new "user@test.com", "password", "user_key"
+      @client.version.should == 3
+    end
+    
+    it "should set variables with version" do
+      @client = Pardot::Client.new "user@test.com", "password", "user_key", 4
+      @client.version.should == 4
+    end
+
+  end
+end
diff --git a/spec/pardot/http_spec.rb b/spec/pardot/http_spec.rb
index 9b98e70..0039887 100644
--- a/spec/pardot/http_spec.rb
+++ b/spec/pardot/http_spec.rb
@@ -68,5 +68,65 @@ def post object = "foo", path = "/bar", params = {}
     end
     
   end
+
+  describe "getV4" do
+    
+    def get object = "foo", path = "/bar", params = {}
+      @client.version = "4"
+      @client.get object, path, params
+    end
+    
+    it "should notice errors and raise them as Pardot::ResponseError" do
+      fake_get "/api/foo/version/4/bar?api_key=my_api_key&format=simple&user_key=bar",
+               %(?xml version="1.0" encoding="UTF-8"?>\n<rsp stat="fail" version="1.0">\n   <err code="15">Login failed</err>\n</rsp>\n)
+      
+      lambda { get }.should raise_error(Pardot::ResponseError)
+    end
+    
+    it "should catch and reraise SocketErrors as Pardot::NetError" do
+      Pardot::Client.should_receive(:get).and_raise(SocketError)
+      
+      lambda { get }.should raise_error(Pardot::NetError)
+    end
+    
+    it "should call handle_expired_api_key when the api key expires" do
+      fake_get "/api/foo/version/4/bar?api_key=my_api_key&format=simple&user_key=bar",
+               %(?xml version="1.0" encoding="UTF-8"?>\n<rsp stat="fail" version="1.0">\n   <err code="15">Invalid API key or user key</err>\n</rsp>\n)
+      
+      @client.should_receive(:handle_expired_api_key)
+      get
+    end
+    
+  end
+  
+  describe "postV4" do
+    
+    def post object = "foo", path = "/bar", params = {}
+      @client.version = "4"
+      @client.post object, path, params
+    end
+    
+    it "should notice errors and raise them as Pardot::ResponseError" do
+      fake_post "/api/foo/version/4/bar?api_key=my_api_key&format=simple&user_key=bar",
+                %(?xml version="1.0" encoding="UTF-8"?>\n<rsp stat="fail" version="1.0">\n   <err code="15">Login failed</err>\n</rsp>\n)
+      
+      lambda { post }.should raise_error(Pardot::ResponseError)
+    end
+    
+    it "should catch and reraise SocketErrors as Pardot::NetError" do
+      Pardot::Client.should_receive(:post).and_raise(SocketError)
+      
+      lambda { post }.should raise_error(Pardot::NetError)
+    end
+    
+    it "should call handle_expired_api_key when the api key expires" do
+      fake_post "/api/foo/version/4/bar?api_key=my_api_key&format=simple&user_key=bar",
+                %(?xml version="1.0" encoding="UTF-8"?>\n<rsp stat="fail" version="1.0">\n   <err code="15">Invalid API key or user key</err>\n</rsp>\n)
+      
+      @client.should_receive(:handle_expired_api_key)
+      post
+    end
+    
+  end
   
 end
\ No newline at end of file