diff --git a/app/controllers/api/v2/mappings_controller.rb b/app/controllers/api/v2/mappings_controller.rb
index 4490e4af..186d6891 100644
--- a/app/controllers/api/v2/mappings_controller.rb
+++ b/app/controllers/api/v2/mappings_controller.rb
@@ -5,6 +5,27 @@ module Api
       def searchable_columns
         []
       end
+
+      def create
+        instantiate_resource
+        resource.user = current_user if current_user.present?
+        resource.updated_by = current_user if current_user.present?
+        authorize resource
+        create_action
+        respond_with_resource
+      end
+
+      def update
+        resource.updated_by = current_user if current_user.present?
+        update_action
+        respond_with_resource
+      end
+
+      def destroy
+        resource.updated_by = current_user if current_user.present?
+        destroy_action
+        head :no_content
+      end
     end
   end
 end
diff --git a/app/controllers/mappings_controller.rb b/app/controllers/mappings_controller.rb
index de2c8ea1..86db023e 100644
--- a/app/controllers/mappings_controller.rb
+++ b/app/controllers/mappings_controller.rb
@@ -19,10 +19,10 @@ class MappingsController < ApplicationController
     @mapping = Mapping.new(mapping_params)
     authorize @mapping
     @mapping.user = current_user
+    @mapping.updated_by = current_user
 
     if @mapping.save
       render json: @mapping, status: :created
-      Events::NewMapping.publish!(@mapping, current_user)
     else
       render json: @mapping.errors, status: :unprocessable_entity
     end
@@ -32,8 +32,10 @@ class MappingsController < ApplicationController
   def update
     @mapping = Mapping.find(params[:id])
     authorize @mapping
+    @mapping.updated_by = current_user
+    @mapping.assign_attributes(mapping_params)
 
-    if @mapping.update_attributes(mapping_params)
+    if @mapping.save
       head :no_content
     else
       render json: @mapping.errors, status: :unprocessable_entity
@@ -44,14 +46,7 @@ class MappingsController < ApplicationController
   def destroy
     @mapping = Mapping.find(params[:id])
     authorize @mapping
-
-    mappable = @mapping.mappable
-    if mappable.defer_to_map
-      mappable.permission = mappable.defer_to_map.permission
-      mappable.defer_to_map_id = nil
-      mappable.save
-    end
-
+    @mapping.updated_by = current_user
     @mapping.destroy
 
     head :no_content
diff --git a/app/models/event.rb b/app/models/event.rb
index 02c6d698..cf974664 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 class Event < ApplicationRecord
-  KINDS = %w(user_present_on_map conversation_started_on_map topic_added_to_map synapse_added_to_map).freeze
+  KINDS = %w(user_present_on_map conversation_started_on_map 
+               topic_added_to_map topic_moved_on_map topic_removed_from_map
+               synapse_added_to_map synapse_removed_from_map
+               topic_updated synapse_updated).freeze
 
-  # has_many :notifications, dependent: :destroy
   belongs_to :eventable, polymorphic: true
   belongs_to :map
   belongs_to :user
@@ -14,18 +16,12 @@ class Event < ApplicationRecord
   validates :kind, inclusion: { in: KINDS }
   validates :eventable, presence: true
 
-  # def notify!(user)
-  #  notifications.create!(user: user)
-  # end
-
   def belongs_to?(this_user)
     user_id == this_user.id
   end
 
   def notify_webhooks!
-    # group = self.discussion.group
     map.webhooks.each { |webhook| WebhookService.publish! webhook: webhook, event: self }
-    # group.webhooks.each           { |webhook| WebhookService.publish! webhook: webhook, event: self }
   end
   handle_asynchronously :notify_webhooks!
 end
diff --git a/app/models/events/new_mapping.rb b/app/models/events/new_mapping.rb
deleted file mode 100644
index 889c69bc..00000000
--- a/app/models/events/new_mapping.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-# frozen_string_literal: true
-class Events::NewMapping < Event
-  # after_create :notify_users!
-
-  def self.publish!(mapping, user)
-    create!(kind: mapping.mappable_type == 'Topic' ? 'topic_added_to_map' : 'synapse_added_to_map',
-            eventable: mapping,
-            map: mapping.map,
-            user: user)
-  end
-end
diff --git a/app/models/events/synapse_added_to_map.rb b/app/models/events/synapse_added_to_map.rb
new file mode 100644
index 00000000..5afa885d
--- /dev/null
+++ b/app/models/events/synapse_added_to_map.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class Events::SynapseAddedToMap < Event
+  # after_create :notify_users!
+
+  def self.publish!(synapse, map, user, meta)
+    create!(kind: 'synapse_added_to_map',
+            eventable: synapse,
+            map: map,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/synapse_removed_from_map.rb b/app/models/events/synapse_removed_from_map.rb
new file mode 100644
index 00000000..b64035dd
--- /dev/null
+++ b/app/models/events/synapse_removed_from_map.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class Events::SynapseRemovedFromMap < Event
+  # after_create :notify_users!
+
+  def self.publish!(synapse, map, user, meta)
+    create!(kind: 'synapse_removed_from_map',
+            eventable: synapse,
+            map: map,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/synapse_updated.rb b/app/models/events/synapse_updated.rb
new file mode 100644
index 00000000..0d85cbe8
--- /dev/null
+++ b/app/models/events/synapse_updated.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+class Events::SynapseUpdated < Event
+  # after_create :notify_users!
+
+  def self.publish!(synapse, user, meta)
+    create!(kind: 'synapse_updated',
+            eventable: synapse,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/topic_added_to_map.rb b/app/models/events/topic_added_to_map.rb
new file mode 100644
index 00000000..a3fa62cf
--- /dev/null
+++ b/app/models/events/topic_added_to_map.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class Events::TopicAddedToMap < Event
+  # after_create :notify_users!
+
+  def self.publish!(topic, map, user, meta)
+    create!(kind: 'topic_added_to_map',
+            eventable: topic,
+            map: map,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/topic_moved_on_map.rb b/app/models/events/topic_moved_on_map.rb
new file mode 100644
index 00000000..08d01277
--- /dev/null
+++ b/app/models/events/topic_moved_on_map.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class Events::TopicMovedOnMap < Event
+  # after_create :notify_users!
+
+  def self.publish!(topic, map, user, meta)
+    create!(kind: 'topic_moved_on_map',
+            eventable: topic,
+            map: map,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/topic_removed_from_map.rb b/app/models/events/topic_removed_from_map.rb
new file mode 100644
index 00000000..2f03ec26
--- /dev/null
+++ b/app/models/events/topic_removed_from_map.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class Events::TopicRemovedFromMap < Event
+  # after_create :notify_users!
+
+  def self.publish!(topic, map, user, meta)
+    create!(kind: 'topic_removed_from_map',
+            eventable: topic,
+            map: map,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/events/topic_updated.rb b/app/models/events/topic_updated.rb
new file mode 100644
index 00000000..fd41a4d6
--- /dev/null
+++ b/app/models/events/topic_updated.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+class Events::TopicUpdated < Event
+  # after_create :notify_users!
+
+  def self.publish!(topic, user, meta)
+    create!(kind: 'topic_updated',
+            eventable: topic,
+            user: user,
+            meta: meta)
+  end
+end
diff --git a/app/models/mapping.rb b/app/models/mapping.rb
index f7219008..99d23db0 100644
--- a/app/models/mapping.rb
+++ b/app/models/mapping.rb
@@ -6,6 +6,7 @@ class Mapping < ApplicationRecord
   belongs_to :mappable, polymorphic: true
   belongs_to :map, class_name: 'Map', foreign_key: 'map_id', touch: true
   belongs_to :user
+  belongs_to :updated_by, class_name: 'User'
 
   validates :xloc, presence: true,
                    unless: proc { |m| m.mappable_type == 'Synapse' }
@@ -16,6 +17,10 @@ class Mapping < ApplicationRecord
 
   delegate :name, to: :user, prefix: true
 
+  after_create :after_created
+  after_update :after_updated
+  before_destroy :before_destroyed
+
   def user_image
     user.image.url
   end
@@ -23,4 +28,35 @@ class Mapping < ApplicationRecord
   def as_json(_options = {})
     super(methods: [:user_name, :user_image])
   end
+
+  def after_created
+    if mappable_type == 'Topic'
+      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
+      Events::TopicAddedToMap.publish!(mappable, map, user, meta)
+    elsif mappable_type == 'Synapse'
+      Events::SynapseAddedToMap.publish!(mappable, map, user, meta)
+    end
+  end
+
+  def after_updated
+    if mappable_type == 'Topic' and (xloc_changed? or yloc_changed?)
+      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
+      Events::TopicMovedOnMap.publish!(mappable, map, updated_by, meta)
+    end
+  end
+
+  def before_destroyed
+    if mappable.defer_to_map
+      mappable.permission = mappable.defer_to_map.permission
+      mappable.defer_to_map_id = nil
+      mappable.save
+    end
+
+    meta = {'mapping_id': id}
+    if mappable_type == 'Topic'
+      Events::TopicRemovedFromMap.publish!(mappable, map, updated_by, meta)
+    elsif mappable_type == 'Synapse'
+      Events::SynapseRemovedFromMap.publish!(mappable, map, updated_by, meta)
+    end
+  end
 end
diff --git a/app/models/synapse.rb b/app/models/synapse.rb
index 08512e4f..d14a18f4 100644
--- a/app/models/synapse.rb
+++ b/app/models/synapse.rb
@@ -22,6 +22,8 @@ class Synapse < ApplicationRecord
     where(topic1_id: topic_id).or(where(topic2_id: topic_id))
   }
 
+  after_update :after_updated
+
   delegate :name, to: :user, prefix: true
 
   def user_image
@@ -39,4 +41,15 @@ class Synapse < ApplicationRecord
   def as_json(_options = {})
     super(methods: [:user_name, :user_image, :collaborator_ids])
   end
+
+  def after_updated
+    attrs = ['desc', 'category', 'permission', 'defer_to_map_id']
+    if attrs.any? {|k| changed_attributes.key?(k)}
+      new = self.attributes.select {|k| attrs.include?(k) }
+      old = changed_attributes.select {|k| attrs.include?(k) }
+      meta = new.merge(old) # we are prioritizing the old values, keeping them 
+      meta['changed'] = changed_attributes.keys.select {|k| attrs.include?(k) }
+      Events::SynapseUpdated.publish!(self, user, meta)
+    end
+  end
 end
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 256fc604..e5ea90ee 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -16,6 +16,7 @@ class Topic < ApplicationRecord
   belongs_to :metacode
 
   before_create :create_metamap?
+  after_update :after_updated
 
   validates :permission, presence: true
   validates :permission, inclusion: { in: Perm::ISSIONS.map(&:to_s) }
@@ -135,4 +136,15 @@ class Topic < ApplicationRecord
     self.link = Rails.application.routes.url_helpers
                      .map_url(host: ENV['MAILER_DEFAULT_URL'], id: @map.id)
   end
+
+  def after_updated
+    attrs = ['name', 'desc', 'link', 'metacode_id', 'permission', 'defer_to_map_id']
+    if attrs.any? {|k| changed_attributes.key?(k)}
+      new = self.attributes.select {|k| attrs.include?(k) }
+      old = changed_attributes.select {|k| attrs.include?(k) }
+      meta = new.merge(old) # we are prioritizing the old values, keeping them 
+      meta['changed'] = changed_attributes.keys.select {|k| attrs.include?(k) }
+      Events::TopicUpdated.publish!(self, user, meta)
+    end
+  end
 end
diff --git a/app/models/webhooks/slack/base.rb b/app/models/webhooks/slack/base.rb
index ba4e9ea5..27f95861 100644
--- a/app/models/webhooks/slack/base.rb
+++ b/app/models/webhooks/slack/base.rb
@@ -16,45 +16,14 @@ Webhooks::Slack::Base = Struct.new(:webhook, :event) do
 
   delegate :channel, to: :webhook
 
-  def attachments
-    [{
-      title:       attachment_title,
-      text:        attachment_text,
-      fields:      attachment_fields,
-      fallback:    attachment_fallback
-    }]
-  end
-
   alias_method :read_attribute_for_serialization, :send
 
   private
 
-  # def motion_vote_field
-  #  {
-  #    title: "Vote on this proposal",
-  #    value: "#{proposal_link(eventable, "yes")} · " +
-  #           "#{proposal_link(eventable, "abstain")} · " +
-  #           "#{proposal_link(eventable, "no")} · " +
-  #           "#{proposal_link(eventable, "block")}"
-  #  }
-  # end
-
   def view_map_on_metamaps(text = nil)
     "<#{map_url(event.map)}|#{text || event.map.name}>"
   end
 
-  # def view_discussion_on_loomio(params = {})
-  #  { value: discussion_link(I18n.t(:"webhooks.slack.view_it_on_loomio"), params) }
-  # end
-
-  # def proposal_link(proposal, position = nil)
-  #  discussion_link position || proposal.name, { proposal: proposal.key, position: position }
-  # end
-
-  # def discussion_link(text = nil, params = {})
-  #  "<#{discussion_url(eventable.map, params)}|#{text || eventable.discussion.title}>"
-  # end
-
   def eventable
     @eventable ||= event.eventable
   end
@@ -63,12 +32,3 @@ Webhooks::Slack::Base = Struct.new(:webhook, :event) do
     @author ||= eventable.author
   end
 end
-
-# webhooks:
-#    slack:
-#      motion_closed: "*%{name}* has closed"
-#      motion_closing_soon: "*%{name}* has a proposal closing in 24 hours"
-#      motion_outcome_created: "*%{author}* published an outcome in *%{name}*"
-#      motion_outcome_updated: "*%{author}* updated the outcome for *%{name}*"
-#      new_motion: "*%{author}* started a new proposal in *%{name}*"
-#      view_it_on_loomio: "View it on Loomio"
diff --git a/app/models/webhooks/slack/conversation_started_on_map.rb b/app/models/webhooks/slack/conversation_started_on_map.rb
index daf2270e..6b6595ce 100644
--- a/app/models/webhooks/slack/conversation_started_on_map.rb
+++ b/app/models/webhooks/slack/conversation_started_on_map.rb
@@ -3,24 +3,4 @@ class Webhooks::Slack::ConversationStartedOnMap < Webhooks::Slack::Base
   def text
     "There is a live conversation starting on map *#{event.map.name}*. #{view_map_on_metamaps('Join in!')}"
   end
-  # TODO: it would be sweet if it sends it with the metacode as the icon_url
-
-  def attachment_fallback
-    '' # {}"*#{eventable.name}*\n#{eventable.description}\n"
-  end
-
-  def attachment_title
-    '' # proposal_link(eventable)
-  end
-
-  def attachment_text
-    '' # "#{eventable.description}\n"
-  end
-
-  def attachment_fields
-    [{
-      title: 'nothing',
-      value: 'nothing'
-    }] # [motion_vote_field]
-  end
 end
diff --git a/app/models/webhooks/slack/synapse_added_to_map.rb b/app/models/webhooks/slack/synapse_added_to_map.rb
index 5157afa7..3d944878 100644
--- a/app/models/webhooks/slack/synapse_added_to_map.rb
+++ b/app/models/webhooks/slack/synapse_added_to_map.rb
@@ -1,25 +1,7 @@
 # frozen_string_literal: true
 class Webhooks::Slack::SynapseAddedToMap < Webhooks::Slack::Base
   def text
-    "\"*#{eventable.mappable.topic1.name}* #{eventable.mappable.desc || '->'} *#{eventable.mappable.topic2.name}*\" was added as a connection to the map *#{view_map_on_metamaps}*"
-  end
-
-  def attachment_fallback
-    '' # {}"*#{eventable.name}*\n#{eventable.description}\n"
-  end
-
-  def attachment_title
-    '' # proposal_link(eventable)
-  end
-
-  def attachment_text
-    '' # "#{eventable.description}\n"
-  end
-
-  def attachment_fields
-    [{
-      title: 'nothing',
-      value: 'nothing'
-    }] # [motion_vote_field]
+    connector = eventable.desc.empty? ? '->' : eventable.desc
+    "\"*#{eventable.topic1.name}* #{connector} *#{eventable.topic2.name}*\" was added as a connection by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
   end
 end
diff --git a/app/models/webhooks/slack/synapse_removed_from_map.rb b/app/models/webhooks/slack/synapse_removed_from_map.rb
new file mode 100644
index 00000000..06d31206
--- /dev/null
+++ b/app/models/webhooks/slack/synapse_removed_from_map.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+class Webhooks::Slack::SynapseRemovedFromMap < Webhooks::Slack::Base
+  def text
+    connector = eventable.desc.empty? ? '->' : eventable.desc
+    # todo express correct directionality of arrows when desc is empty
+    "\"*#{eventable.topic1.name}* #{connector} *#{eventable.topic2.name}*\" was removed by *#{event.user.name}* as a connection from the map *#{view_map_on_metamaps}*"
+  end
+end
diff --git a/app/models/webhooks/slack/topic_added_to_map.rb b/app/models/webhooks/slack/topic_added_to_map.rb
index d3a19760..4f726069 100644
--- a/app/models/webhooks/slack/topic_added_to_map.rb
+++ b/app/models/webhooks/slack/topic_added_to_map.rb
@@ -1,26 +1,7 @@
 # frozen_string_literal: true
 class Webhooks::Slack::TopicAddedToMap < Webhooks::Slack::Base
   def text
-    "New #{eventable.mappable.metacode.name} topic *#{eventable.mappable.name}* was added to the map *#{view_map_on_metamaps}*"
+    "*#{eventable.name}* was added by *#{event.user.name}* to the map *#{view_map_on_metamaps}*"
   end
   # TODO: it would be sweet if it sends it with the metacode as the icon_url
-
-  def attachment_fallback
-    '' # {}"*#{eventable.name}*\n#{eventable.description}\n"
-  end
-
-  def attachment_title
-    '' # proposal_link(eventable)
-  end
-
-  def attachment_text
-    '' # "#{eventable.description}\n"
-  end
-
-  def attachment_fields
-    [{
-      title: 'nothing',
-      value: 'nothing'
-    }] # [motion_vote_field]
-  end
 end
diff --git a/app/models/webhooks/slack/topic_moved_on_map.rb b/app/models/webhooks/slack/topic_moved_on_map.rb
new file mode 100644
index 00000000..dfe088ed
--- /dev/null
+++ b/app/models/webhooks/slack/topic_moved_on_map.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+class Webhooks::Slack::TopicMovedOnMap < Webhooks::Slack::Base
+  def text
+    "*#{eventable.name}* was moved by *#{event.user.name}* on the map *#{view_map_on_metamaps}*"
+  end
+end
diff --git a/app/models/webhooks/slack/topic_removed_from_map.rb b/app/models/webhooks/slack/topic_removed_from_map.rb
new file mode 100644
index 00000000..05a79c3b
--- /dev/null
+++ b/app/models/webhooks/slack/topic_removed_from_map.rb
@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+class Webhooks::Slack::TopicRemovedFromMap < Webhooks::Slack::Base
+  def text
+    "*#{eventable.name}* was removed by *#{event.user.name}* from the map *#{view_map_on_metamaps}*"
+  end
+end
diff --git a/app/models/webhooks/slack/user_present_on_map.rb b/app/models/webhooks/slack/user_present_on_map.rb
index c3185e48..4cee2992 100644
--- a/app/models/webhooks/slack/user_present_on_map.rb
+++ b/app/models/webhooks/slack/user_present_on_map.rb
@@ -3,24 +3,4 @@ class Webhooks::Slack::UserPresentOnMap < Webhooks::Slack::Base
   def text
     "Mapper *#{event.user.name}* has joined the map *#{event.map.name}*. #{view_map_on_metamaps('Map with them')}"
   end
-  # TODO: it would be sweet if it sends it with the metacode as the icon_url
-
-  def attachment_fallback
-    '' # {}"*#{eventable.name}*\n#{eventable.description}\n"
-  end
-
-  def attachment_title
-    '' # proposal_link(eventable)
-  end
-
-  def attachment_text
-    '' # "#{eventable.description}\n"
-  end
-
-  def attachment_fields
-    [{
-      title: 'nothing',
-      value: 'nothing'
-    }] # [motion_vote_field]
-  end
 end
diff --git a/app/serializers/api/v2/mapping_serializer.rb b/app/serializers/api/v2/mapping_serializer.rb
index 19e7318e..30c9bd7f 100644
--- a/app/serializers/api/v2/mapping_serializer.rb
+++ b/app/serializers/api/v2/mapping_serializer.rb
@@ -14,6 +14,7 @@ module Api
       def self.embeddable
         {
           user: {},
+          updated_by: {},
           map: {}
         }
       end
diff --git a/app/serializers/webhook_serializer.rb b/app/serializers/webhook_serializer.rb
index a2acf869..c1f0e266 100644
--- a/app/serializers/webhook_serializer.rb
+++ b/app/serializers/webhook_serializer.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 class WebhookSerializer < ActiveModel::Serializer
-  attributes :text, :username, :icon_url # , :attachments
+  attributes :text, :username, :icon_url
   attribute :channel, if: :has_channel?
 
   def has_channel?
diff --git a/db/migrate/20161214140124_add_meta_to_events.rb b/db/migrate/20161214140124_add_meta_to_events.rb
new file mode 100644
index 00000000..edbee3d6
--- /dev/null
+++ b/db/migrate/20161214140124_add_meta_to_events.rb
@@ -0,0 +1,5 @@
+class AddMetaToEvents < ActiveRecord::Migration[5.0]
+  def change
+    add_column :events, :meta, :json
+  end
+end
diff --git a/db/migrate/20161216174257_add_updated_by_to_mappings.rb b/db/migrate/20161216174257_add_updated_by_to_mappings.rb
new file mode 100644
index 00000000..e28b8281
--- /dev/null
+++ b/db/migrate/20161216174257_add_updated_by_to_mappings.rb
@@ -0,0 +1,5 @@
+class AddUpdatedByToMappings < ActiveRecord::Migration[5.0]
+  def change
+      add_reference :mappings, :updated_by, foreign_key: {to_table: :users}
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 5839929c..b30d597e 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20161125175229) do
+ActiveRecord::Schema.define(version: 20161216174257) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -49,6 +49,7 @@ ActiveRecord::Schema.define(version: 20161125175229) do
     t.integer  "map_id"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.json     "meta"
     t.index ["eventable_type", "eventable_id"], name: "index_events_on_eventable_type_and_eventable_id", using: :btree
     t.index ["map_id"], name: "index_events_on_map_id", using: :btree
     t.index ["user_id"], name: "index_events_on_user_id", using: :btree
@@ -128,10 +129,12 @@ ActiveRecord::Schema.define(version: 20161125175229) do
     t.datetime "updated_at",    null: false
     t.integer  "mappable_id"
     t.string   "mappable_type"
+    t.integer  "updated_by_id"
     t.index ["map_id", "synapse_id"], name: "index_mappings_on_map_id_and_synapse_id", using: :btree
     t.index ["map_id", "topic_id"], name: "index_mappings_on_map_id_and_topic_id", using: :btree
     t.index ["map_id"], name: "index_mappings_on_map_id", using: :btree
     t.index ["mappable_id", "mappable_type"], name: "index_mappings_on_mappable_id_and_mappable_type", using: :btree
+    t.index ["updated_by_id"], name: "index_mappings_on_updated_by_id", using: :btree
     t.index ["user_id"], name: "index_mappings_on_user_id", using: :btree
   end
 
@@ -336,5 +339,6 @@ ActiveRecord::Schema.define(version: 20161125175229) do
   add_foreign_key "mailboxer_conversation_opt_outs", "mailboxer_conversations", column: "conversation_id", name: "mb_opt_outs_on_conversations_id"
   add_foreign_key "mailboxer_notifications", "mailboxer_conversations", column: "conversation_id", name: "notifications_on_conversation_id"
   add_foreign_key "mailboxer_receipts", "mailboxer_notifications", column: "notification_id", name: "receipts_on_notification_id"
+  add_foreign_key "mappings", "users", column: "updated_by_id"
   add_foreign_key "tokens", "users"
 end
diff --git a/doc/api/apis/mappings.raml b/doc/api/apis/mappings.raml
index 00298387..af4965cb 100644
--- a/doc/api/apis/mappings.raml
+++ b/doc/api/apis/mappings.raml
@@ -1,6 +1,6 @@
 #type: collection
 get:
-  is: [ embeddable: { embedFields: "user,map" }, orderable, pageable ]
+  is: [ embeddable: { embedFields: "user,updated_by,map" }, orderable, pageable ]
   securedBy: [ null, token, oauth_2_0, cookie ]
   responses:
     200:
@@ -31,7 +31,7 @@ post:
 /{id}:
   #type: item
   get:
-    is: [ embeddable: { embedFields: "user,map" } ]
+    is: [ embeddable: { embedFields: "user,updated_by,map" } ]
     securedBy: [ null, token, oauth_2_0, cookie ]
     responses:
       200:
diff --git a/doc/api/examples/mapping.json b/doc/api/examples/mapping.json
index c4aa87bf..93d38bdb 100644
--- a/doc/api/examples/mapping.json
+++ b/doc/api/examples/mapping.json
@@ -6,6 +6,7 @@
     "mappable_id": 1,
     "mappable_type": "Synapse",
     "user_id": 1,
+    "updated_by_id": 1,
     "map_id": 1
   }
 }
diff --git a/doc/api/examples/mappings.json b/doc/api/examples/mappings.json
index 5a4a99c3..99f2e58d 100644
--- a/doc/api/examples/mappings.json
+++ b/doc/api/examples/mappings.json
@@ -8,6 +8,7 @@
       "mappable_type": "Topic",
       "updated_at": "2016-03-25T08:44:07.152Z",
       "user_id": 1,
+      "updated_by_id": 1,
       "xloc": -271,
       "yloc": 22
     },
@@ -19,6 +20,7 @@
       "mappable_type": "Topic",
       "updated_at": "2016-03-25T08:44:13.907Z",
       "user_id": 1,
+      "updated_by_id": 1,
       "xloc": -12,
       "yloc": 61
     },
@@ -30,6 +32,7 @@
       "mappable_type": "Topic",
       "updated_at": "2016-03-25T08:44:19.333Z",
       "user_id": 1,
+      "updated_by_id": 1,
       "xloc": -93,
       "yloc": -90
     },
@@ -40,7 +43,8 @@
       "mappable_id": 1,
       "mappable_type": "Synapse",
       "updated_at": "2016-03-25T08:44:21.337Z",
-      "user_id": 1
+      "user_id": 1,
+      "updated_by_id": 1
     }
   ],
   "page": {
diff --git a/doc/api/schemas/_mapping.json b/doc/api/schemas/_mapping.json
index 8789c5ec..efd12c92 100644
--- a/doc/api/schemas/_mapping.json
+++ b/doc/api/schemas/_mapping.json
@@ -35,6 +35,12 @@
     },
     "user": {
       "$ref": "_user.json"
+    },
+    "updated_by_id": {
+      "$ref": "_id.json"
+    },
+    "updated_by": {
+      "$ref": "_user.json"
     }
   },
   "required": [
@@ -56,6 +62,12 @@
         { "required": [ "user_id" ] },
         { "required": [ "user" ] }
       ]
+    },
+    {
+      "oneOf": [
+        { "required": [ "updated_by_id" ] },
+        { "required": [ "updated_by" ] }
+      ]
     }
   ]
 }