diff --git a/ruby/lib/jam_ruby/models/jam_track.rb b/ruby/lib/jam_ruby/models/jam_track.rb
index 7db7b3905..a00206792 100644
--- a/ruby/lib/jam_ruby/models/jam_track.rb
+++ b/ruby/lib/jam_ruby/models/jam_track.rb
@@ -528,6 +528,28 @@ module JamRuby
       "#{self.name} (#{self.original_artist})"
     end
 
+    def self.latestPurchase(user_id)
+      jtx_created = JamTrackRight
+        .select('created_at')
+        .where(user_id: user_id)
+        .order('created_at DESC')
+        .limit(1)
+      jtx_created.first.created_at.to_i
+    end
+
+    def self.mixdownChecksum(user_id, jam_track_id)
+      dates = JamTrackMixdown
+        .select('created_at')
+        .where(user_id:  user_id, jam_track_id: jam_track_id)
+        .order(:id)
+      
+      dates = dates.map do |date|
+        date.created_at.to_i.to_s
+      end.join('')
+
+      Digest::MD5.hexdigest(dates)
+    end
+
     attr_accessor :preview_generate_error
 
     before_save :jmep_json_generate
diff --git a/web/app/controllers/api_jam_tracks_controller.rb b/web/app/controllers/api_jam_tracks_controller.rb
index a07170432..86af55c28 100644
--- a/web/app/controllers/api_jam_tracks_controller.rb
+++ b/web/app/controllers/api_jam_tracks_controller.rb
@@ -97,8 +97,40 @@ class ApiJamTracksController < ApiController
     end
   end
 
+  def _handlePurchasedHead
+    if jtid = params[:id]
+      if params[:mixcheck]
+        checksum = JamTrack.mixdownChecksum(current_user.id, jtid)
+        head :ok, checksum: checksum
+        return
+      else
+        # if the requested jamtrack is not purchased, send status code 204
+        if 0 == JamTrack.where(id: jtid, user_id: current_user.id).count
+          head(:no_content)
+          return
+        end
+      end
+    elsif params[:syncbuys]
+      syncbuys = params[:syncbuys].to_i
+      latestPurchase = JamTrack.latestPurchase(current_user.id)
+      if 0 == syncbuys || (0 < latestPurchase && (latestPurchase <= syncbuys))
+        head :no_content, latestpurchase: latestPurchase
+        return 
+      else
+        head :ok, latestpurchase: latestPurchase
+        return
+      end
+    end
+    head(:ok)
+  end
+
   def purchased
-    params[:show_purchased_only] = true
+    if request.head?
+      self._handlePurchasedHead 
+      return
+    end
+
+   params[:show_purchased_only] = true
     data = JamTrack.index(params, current_user)
     @jam_tracks, @next = data[0], data[1]
 
diff --git a/web/app/controllers/api_users_controller.rb b/web/app/controllers/api_users_controller.rb
index e664e4697..c267e23bd 100644
--- a/web/app/controllers/api_users_controller.rb
+++ b/web/app/controllers/api_users_controller.rb
@@ -78,7 +78,7 @@ ApiUsersController < ApiController
         email: params[:email],
         password: params[:password],
         password_confirmation: params[:password],
-        terms_of_service: params[:terms],
+        terms_of_service: params[:terms_of_service].to_i,
         location: {:country => nil, :state => nil, :city => nil},
         signup_hint: signup_hint,
         gift_card: params[:gift_card],
diff --git a/web/app/views/api_jam_track_mixdowns/show.rabl b/web/app/views/api_jam_track_mixdowns/show.rabl
index a599f8a64..4ec76afb1 100644
--- a/web/app/views/api_jam_track_mixdowns/show.rabl
+++ b/web/app/views/api_jam_track_mixdowns/show.rabl
@@ -2,6 +2,10 @@ object @jam_track_mixdown
 
 attributes :id, :name, :description, :jam_track_id
 
+node :created_at do |item|
+  item.created_at.to_i
+end
+
 node :settings do |item|
   JSON.parse(item.settings)
 end
diff --git a/web/app/views/api_jam_tracks/show_for_client.rabl b/web/app/views/api_jam_tracks/show_for_client.rabl
index da99ba6e9..8d19fc807 100644
--- a/web/app/views/api_jam_tracks/show_for_client.rabl
+++ b/web/app/views/api_jam_tracks/show_for_client.rabl
@@ -10,10 +10,6 @@ node :jmep do |jam_track|
   jam_track.jmep_json ? JSON.parse(jam_track.jmep_json) : nil
 end
 
-node :jam_track_right_id do |jam_track|
-  jam_track.right_for_user(current_user).id
-end
-
 child(:jam_track_tracks => :tracks) {
   attributes :id, :part, :instrument, :track_type, :position
 
@@ -29,6 +25,8 @@ child(:jam_track_tracks => :tracks) {
 node do |jam_track|
   right = jam_track.right_for_user(current_user)
   {
+    jam_track_right_id: right.id,
+    purchased_at: right.created_at.to_i,
     last_mixdown_id: right.last_mixdown_id,
     last_stem_id: right.last_stem_id
   }