diff --git a/speckle_connector/src/actions/cancel_operation.rb b/speckle_connector/src/actions/cancel_operation.rb
new file mode 100644
index 0000000..7424421
--- /dev/null
+++ b/speckle_connector/src/actions/cancel_operation.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require_relative 'action'
+require_relative 'deactivate_diffing'
+require_relative '../convertors/units'
+require_relative '../convertors/to_speckle'
+
+module SpeckleConnector
+  module Actions
+    # Cancel the operation.
+    class CancelOperation < Action
+      # @param state [States::State] the current state of the {App::SpeckleConnectorApp}
+      # @return [States::State] the new updated state object
+      def self.update_state(state, _data)
+        state.ready = false
+        state
+      end
+    end
+  end
+end
diff --git a/speckle_connector/src/actions/send_selection.rb b/speckle_connector/src/actions/send_selection.rb
index 1e61564..cd6a509 100644
--- a/speckle_connector/src/actions/send_selection.rb
+++ b/speckle_connector/src/actions/send_selection.rb
@@ -20,6 +20,11 @@ module SpeckleConnector
         state = DeactivateDiffing.update_state(state, {})
         converter = Converters::ToSpeckle.new(state, @stream_id)
         new_speckle_state, base = converter.convert_selection_to_base(state.user_state.preferences)
+        unless state.ready
+          state = state.with(:@ready => true)
+          return state.with_add_queue('sendOperationCancelled', @stream_id, [])
+        end
+
         id, total_children_count, batches, new_speckle_state = converter.serialize(base, new_speckle_state,
                                                                                    state.user_state.preferences)
         puts("converted #{base.count} objects for stream #{@stream_id}")
@@ -30,10 +35,10 @@ module SpeckleConnector
 
         new_state = state.with_speckle_state(new_speckle_state)
         new_state.with_add_queue('convertedFromSketchup', @stream_id, [
-                                   { is_string: false, val: batches },
-                                   { is_string: true, val: id },
-                                   { is_string: false, val: total_children_count }
-                                 ])
+          { is_string: false, val: batches },
+          { is_string: true, val: id },
+          { is_string: false, val: total_children_count }
+        ])
       end
     end
   end
diff --git a/speckle_connector/src/convertors/to_speckle.rb b/speckle_connector/src/convertors/to_speckle.rb
index 6d3e0ef..f68e3c6 100644
--- a/speckle_connector/src/convertors/to_speckle.rb
+++ b/speckle_connector/src/convertors/to_speckle.rb
@@ -61,6 +61,11 @@ module SpeckleConnector
       # @param speckle_state [States::SpeckleState] the current speckle state of the {States::State}
       # @param parent [Symbol, String] parent of the Sketchup Entity to be converted.
       def convert(entity, preferences, speckle_state, parent = :base)
+        unless state.ready
+          puts 'Terminating..'
+          return speckle_state, nil
+        end
+
         convert = method(:convert)
 
         unless SketchupModel::Reader::SpeckleEntitiesReader.mapped_with_schema?(entity)
diff --git a/speckle_connector/src/states/state.rb b/speckle_connector/src/states/state.rb
index e605d94..68e8037 100644
--- a/speckle_connector/src/states/state.rb
+++ b/speckle_connector/src/states/state.rb
@@ -8,6 +8,9 @@ module SpeckleConnector
     class State < InitialState
       include Immutable::ImmutableUtils
 
+      # @return [Boolean] is state ready for updating.
+      attr_accessor :ready
+
       # @return [States::SketchupState] the state of the Sketchup Application
       attr_reader :sketchup_state
 
@@ -18,6 +21,7 @@ module SpeckleConnector
       attr_reader :user_state
 
       def initialize(user_state, speckle_state, sketchup_state, is_connected)
+        @ready = true
         @speckle_state = speckle_state
         @is_connected = is_connected
         @sketchup_state = sketchup_state
diff --git a/speckle_connector/src/ui/vue_view.rb b/speckle_connector/src/ui/vue_view.rb
index af48d13..07bfeaf 100644
--- a/speckle_connector/src/ui/vue_view.rb
+++ b/speckle_connector/src/ui/vue_view.rb
@@ -29,6 +29,7 @@ require_relative '../actions/isolate_mappings_from_table'
 require_relative '../actions/hide_mappings_from_table'
 require_relative '../actions/select_mappings_from_table'
 require_relative '../actions/show_all_entities'
+require_relative '../actions/cancel_operation'
 
 module SpeckleConnector
   module Ui
@@ -89,7 +90,8 @@ module SpeckleConnector
           isolate_mappings_from_table: Commands::ActionCommand.new(@app, Actions::IsolateMappingsFromTable),
           hide_mappings_from_table: Commands::ActionCommand.new(@app, Actions::HideMappingsFromTable),
           select_mappings_from_table: Commands::ActionCommand.new(@app, Actions::SelectMappingsFromTable),
-          show_all_entities: Commands::ActionCommand.new(@app, Actions::ShowAllEntities)
+          show_all_entities: Commands::ActionCommand.new(@app, Actions::ShowAllEntities),
+          cancel_operation: Commands::ActionCommand.new(@app, Actions::CancelOperation)
         }.freeze
       end
       # rubocop:enable Metrics/MethodLength
diff --git a/ui/src/components/StreamCard.vue b/ui/src/components/StreamCard.vue
index 7f486e7..64e3c79 100644
--- a/ui/src/components/StreamCard.vue
+++ b/ui/src/components/StreamCard.vue
@@ -40,6 +40,14 @@
             <v-img v-if="$vuetify.theme.dark" src="@/assets/SenderWhite.png" max-width="30" />
             <v-img v-else src="@/assets/Sender.png" max-width="30" />
           </v-btn>
+          <v-btn
+              v-tooltip="'Stop'"
+              icon
+              class="mr-3 elevation-2"
+              @click="cancel"
+          >
+            STOP
+          </v-btn>
           <v-btn
             v-tooltip="'Receive'"
             icon
@@ -163,6 +171,10 @@ import streamQuery from '../graphql/stream.gql'
 import ObjectLoader from '@speckle/objectloader'
 import {HostApplications} from '@/utils/hostApplications'
 
+global.sendOperationCancelled = function (streamId) {
+  bus.$emit(`send-operation-cancelled-${streamId}`)
+}
+
 global.convertedFromSketchup = function (streamId, batches, commitId, totalChildrenCount) {
   bus.$emit(`sketchup-objects-${streamId}`, batches, commitId, totalChildrenCount)
 }
@@ -314,6 +326,9 @@ export default {
 
       await this.createCommit(batches, commitId, totalChildrenCount)
     })
+    bus.$on(`send-operation-cancelled-${this.streamId}`, () => {
+      this.loadingSend = false
+    })
     bus.$on(`sketchup-received-${this.streamId}`, () => {
       console.log('>>> SpeckleSketchUp: Finished receiving in sketchup', this.streamId)
       this.loadingReceive = false
@@ -435,6 +450,9 @@ export default {
       console.log('>>> SpeckleSketchUp: Objects requested from SketchUp')
       await this.sleep(2000)
     },
+    cancel(){
+      sketchup.exec({name:"cancel_operation" , data: {}})
+    },
     async createCommit(batches, commitId, totalChildrenCount) {
       if (batches.length === 0) {
         this.loadingSend = false