diff --git a/lib/entities/alarm_control_panel/widgets/alarm_control_panel_controls.widget.dart b/lib/entities/alarm_control_panel/widgets/alarm_control_panel_controls.widget.dart
index 0d2bb92..ff9e707 100644
--- a/lib/entities/alarm_control_panel/widgets/alarm_control_panel_controls.widget.dart
+++ b/lib/entities/alarm_control_panel/widgets/alarm_control_panel_controls.widget.dart
@@ -26,10 +26,10 @@ class _AlarmControlPanelControlsWidgetWidgetState extends State<AlarmControlPane
 
   void _callService(AlarmControlPanelEntity entity, String service) {
     ConnectionManager().callService(
-      entity.domain,
-      service,
-      entity.entityId,
-      {"code": "$code"}
+      domain: entity.domain,
+      service: service,
+      entityId: entity.entityId,
+      data: {"code": "$code"}
     );
     setState(() {
       code = "";
@@ -62,10 +62,9 @@ class _AlarmControlPanelControlsWidgetWidgetState extends State<AlarmControlPane
               child: new Text("Yes"),
               onPressed: () {
                 ConnectionManager().callService(
-                  entity.domain,
-                  "alarm_trigger",
-                  entity.entityId,
-                  null
+                  domain: entity.domain,
+                  service: "alarm_trigger",
+                  entityId: entity.entityId
                 );
                 Navigator.of(context).pop();
               },
diff --git a/lib/entities/climate/widgets/climate_controls.dart b/lib/entities/climate/widgets/climate_controls.dart
index 711a752..f05e63a 100644
--- a/lib/entities/climate/widgets/climate_controls.dart
+++ b/lib/entities/climate/widgets/climate_controls.dart
@@ -84,10 +84,10 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
       setState(() {
         _changedHere = true;
         ConnectionManager().callService(
-          entity.domain,
-          "set_temperature",
-          entity.entityId,
-          {"temperature": "${_tmpTemperature.toStringAsFixed(1)}"}
+          domain: entity.domain,
+          service: "set_temperature",
+          entityId: entity.entityId,
+          data: {"temperature": "${_tmpTemperature.toStringAsFixed(1)}"}
         );
         _resetStateTimer(entity);
       });
@@ -107,10 +107,10 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
       setState(() {
         _changedHere = true;
         ConnectionManager().callService(
-          entity.domain,
-          "set_temperature",
-          entity.entityId,
-          {"target_temp_high": "${_tmpTargetHigh.toStringAsFixed(1)}", "target_temp_low": "${_tmpTargetLow.toStringAsFixed(1)}"}
+          domain: entity.domain,
+          service: "set_temperature",
+          entityId: entity.entityId,
+          data: {"target_temp_high": "${_tmpTargetHigh.toStringAsFixed(1)}", "target_temp_low": "${_tmpTargetLow.toStringAsFixed(1)}"}
         );
         _resetStateTimer(entity);
       });
@@ -121,7 +121,12 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpTargetHumidity = value.roundToDouble();
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_humidity", entity.entityId, {"humidity": "$_tmpTargetHumidity"});
+      ConnectionManager().callService(
+          domain: entity.domain,
+          service: "set_humidity",
+          entityId: entity.entityId,
+          data: {"humidity": "$_tmpTargetHumidity"}
+        );
       _resetStateTimer(entity);
     });
   }
@@ -130,7 +135,12 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpHVACMode = value;
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_hvac_mode", entity.entityId, {"hvac_mode": "$_tmpHVACMode"});
+      ConnectionManager().callService(
+          domain: entity.domain,
+          service: "set_hvac_mode",
+          entityId: entity.entityId,
+          data: {"hvac_mode": "$_tmpHVACMode"}
+        );
       _resetStateTimer(entity);
     });
   }
@@ -139,7 +149,12 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpSwingMode = value;
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_swing_mode", entity.entityId, {"swing_mode": "$_tmpSwingMode"});
+      ConnectionManager().callService(
+          domain: entity.domain,
+          service: "set_swing_mode",
+          entityId: entity.entityId,
+          data: {"swing_mode": "$_tmpSwingMode"}
+        );
       _resetStateTimer(entity);
     });
   }
@@ -148,7 +163,7 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpFanMode = value;
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_fan_mode", entity.entityId, {"fan_mode": "$_tmpFanMode"});
+      ConnectionManager().callService(domain: entity.domain, service: "set_fan_mode", entityId: entity.entityId, data: {"fan_mode": "$_tmpFanMode"});
       _resetStateTimer(entity);
     });
   }
@@ -157,7 +172,7 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpPresetMode = value;
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_preset_mode", entity.entityId, {"preset_mode": "$_tmpPresetMode"});
+      ConnectionManager().callService(domain: entity.domain, service: "set_preset_mode", entityId: entity.entityId, data: {"preset_mode": "$_tmpPresetMode"});
       _resetStateTimer(entity);
     });
   }
@@ -175,7 +190,7 @@ class _ClimateControlWidgetState extends State<ClimateControlWidget> {
     setState(() {
       _tmpAuxHeat = value;
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_aux_heat", entity.entityId, {"aux_heat": "$_tmpAuxHeat"});
+      ConnectionManager().callService(domain: entity.domain, service: "set_aux_heat", entityId: entity.entityId, data: {"aux_heat": "$_tmpAuxHeat"});
       _resetStateTimer(entity);
     });
   }
diff --git a/lib/entities/cover/widgets/cover_controls.widget.dart b/lib/entities/cover/widgets/cover_controls.widget.dart
index 0510c47..5075158 100644
--- a/lib/entities/cover/widgets/cover_controls.widget.dart
+++ b/lib/entities/cover/widgets/cover_controls.widget.dart
@@ -18,7 +18,7 @@ class _CoverControlWidgetState extends State<CoverControlWidget> {
     setState(() {
       _tmpPosition = position.roundToDouble();
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_cover_position", entity.entityId,{"position": _tmpPosition.round()});
+      ConnectionManager().callService(domain: entity.domain, service: "set_cover_position", entityId: entity.entityId, data: {"position": _tmpPosition.round()});
     });
   }
 
@@ -26,7 +26,7 @@ class _CoverControlWidgetState extends State<CoverControlWidget> {
     setState(() {
       _tmpTiltPosition = position.roundToDouble();
       _changedHere = true;
-      ConnectionManager().callService(entity.domain, "set_cover_tilt_position", entity.entityId,{"tilt_position": _tmpTiltPosition.round()});
+      ConnectionManager().callService(domain: entity.domain, service: "set_cover_tilt_position", entityId: entity.entityId, data: {"tilt_position": _tmpTiltPosition.round()});
     });
   }
 
@@ -136,17 +136,17 @@ class _CoverControlWidgetState extends State<CoverControlWidget> {
 class CoverTiltControlsWidget extends StatelessWidget {
   void _open(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "open_cover_tilt", entity.entityId, null);
+        domain: entity.domain, service: "open_cover_tilt", entityId: entity.entityId);
   }
 
   void _close(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "close_cover_tilt", entity.entityId, null);
+        domain: entity.domain, service: "close_cover_tilt", entityId: entity.entityId);
   }
 
   void _stop(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "stop_cover_tilt", entity.entityId, null);
+        domain: entity.domain, service: "stop_cover_tilt", entityId: entity.entityId);
   }
 
   @override
diff --git a/lib/entities/cover/widgets/cover_state.dart b/lib/entities/cover/widgets/cover_state.dart
index 77bed97..b52e60f 100644
--- a/lib/entities/cover/widgets/cover_state.dart
+++ b/lib/entities/cover/widgets/cover_state.dart
@@ -3,17 +3,26 @@ part of '../../../main.dart';
 class CoverStateWidget extends StatelessWidget {
   void _open(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "open_cover", entity.entityId, null);
+        domain: entity.domain,
+        service: "open_cover",
+        entityId: entity.entityId
+      );
   }
 
   void _close(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "close_cover", entity.entityId, null);
+        domain: entity.domain,
+        service: "close_cover",
+        entityId: entity.entityId
+      );
   }
 
   void _stop(CoverEntity entity) {
     ConnectionManager().callService(
-        entity.domain, "stop_cover", entity.entityId, null);
+        domain: entity.domain,
+        service: "stop_cover",
+        entityId: entity.entityId
+      );
   }
 
   @override
diff --git a/lib/entities/date_time/date_time_entity.class.dart b/lib/entities/date_time/date_time_entity.class.dart
index 2db63bd..2146d71 100644
--- a/lib/entities/date_time/date_time_entity.class.dart
+++ b/lib/entities/date_time/date_time_entity.class.dart
@@ -36,6 +36,6 @@ class DateTimeEntity extends Entity {
   }
 
   void setNewState(Map newValue) {
-    ConnectionManager().callService(domain, "set_datetime", entityId, newValue);
+    ConnectionManager().callService(domain: domain, service: "set_datetime", entityId: entityId, data: newValue);
   }
 }
\ No newline at end of file
diff --git a/lib/entities/entity_wrapper.class.dart b/lib/entities/entity_wrapper.class.dart
index 016d004..026abf0 100644
--- a/lib/entities/entity_wrapper.class.dart
+++ b/lib/entities/entity_wrapper.class.dart
@@ -32,15 +32,17 @@ class EntityWrapper {
   void handleTap() {
     switch (uiAction.tapAction) {
       case EntityUIAction.toggle: {
-        ConnectionManager().callService("homeassistant", "toggle", entity.entityId, null);
+        ConnectionManager().callService(domain: "homeassistant", service: "toggle", entityId: entity.entityId);
         break;
       }
 
       case EntityUIAction.callService: {
         if (uiAction.tapService != null) {
-          ConnectionManager().callService(uiAction.tapService.split(".")[0],
-                  uiAction.tapService.split(".")[1], null,
-                  uiAction.tapServiceData);
+          ConnectionManager().callService(
+            domain: uiAction.tapService.split(".")[0],
+            service: uiAction.tapService.split(".")[1],
+            data: uiAction.tapServiceData
+          );
         }
         break;
       }
@@ -74,15 +76,17 @@ class EntityWrapper {
   void handleHold() {
       switch (uiAction.holdAction) {
         case EntityUIAction.toggle: {
-          ConnectionManager().callService("homeassistant", "toggle", entity.entityId, null);
+          ConnectionManager().callService(domain: "homeassistant", service: "toggle", entityId: entity.entityId);
           break;
         }
 
         case EntityUIAction.callService: {
           if (uiAction.holdService != null) {
-            ConnectionManager().callService(uiAction.holdService.split(".")[0],
-                    uiAction.holdService.split(".")[1], null,
-                    uiAction.holdServiceData);
+            ConnectionManager().callService(
+              domain: uiAction.holdService.split(".")[0],
+              service: uiAction.holdService.split(".")[1],
+              data: uiAction.holdServiceData
+            );
           }
           break;
         }
diff --git a/lib/entities/fan/widgets/fan_controls.dart b/lib/entities/fan/widgets/fan_controls.dart
index dae4376..aebe235 100644
--- a/lib/entities/fan/widgets/fan_controls.dart
+++ b/lib/entities/fan/widgets/fan_controls.dart
@@ -25,8 +25,11 @@ class _FanControlsWidgetState extends State<FanControlsWidget> {
       _tmpOscillate = oscillate;
       _changedHere = true;
       ConnectionManager().callService(
-          "fan", "oscillate", entity.entityId,
-          {"oscillating": oscillate});
+          domain: "fan",
+          service: "oscillate",
+          entityId: entity.entityId,
+          data: {"oscillating": oscillate}
+        );
     });
   }
 
@@ -35,8 +38,11 @@ class _FanControlsWidgetState extends State<FanControlsWidget> {
       _tmpDirectionForward = forward;
       _changedHere = true;
       ConnectionManager().callService(
-          "fan", "set_direction", entity.entityId,
-          {"direction": forward ? "forward" : "reverse"});
+          domain: "fan",
+          service: "set_direction",
+          entityId: entity.entityId,
+          data: {"direction": forward ? "forward" : "reverse"}
+        );
     });
   }
 
@@ -45,8 +51,11 @@ class _FanControlsWidgetState extends State<FanControlsWidget> {
       _tmpSpeed = value;
       _changedHere = true;
       ConnectionManager().callService(
-            "fan", "set_speed", entity.entityId,
-            {"speed": value});
+            domain: "fan",
+            service: "set_speed",
+            entityId: entity.entityId,
+            data: {"speed": value}
+          );
     });
   }
 
diff --git a/lib/entities/flat_service_button.widget.dart b/lib/entities/flat_service_button.widget.dart
index df1adcc..097513d 100644
--- a/lib/entities/flat_service_button.widget.dart
+++ b/lib/entities/flat_service_button.widget.dart
@@ -18,7 +18,7 @@ class FlatServiceButton extends StatelessWidget {
   }) : super(key: key);
 
   void _setNewState() {
-    ConnectionManager().callService(serviceDomain, serviceName, entityId, null);
+    ConnectionManager().callService(domain: serviceDomain, service: serviceName, entityId: entityId);
   }
 
   @override
diff --git a/lib/entities/light/widgets/light_controls.dart b/lib/entities/light/widgets/light_controls.dart
index 80da7cf..13f45eb 100644
--- a/lib/entities/light/widgets/light_controls.dart
+++ b/lib/entities/light/widgets/light_controls.dart
@@ -29,8 +29,11 @@ class _LightControlsWidgetState extends State<LightControlsWidget> {
       _tmpBrightness = value.round();
       _changedHere = true;
       ConnectionManager().callService(
-          entity.domain, "turn_on", entity.entityId,
-          {"brightness": _tmpBrightness});
+          domain: entity.domain,
+          service: "turn_on",
+          entityId: entity.entityId,
+          data: {"brightness": _tmpBrightness}
+        );
     });
   }
 
@@ -39,8 +42,11 @@ class _LightControlsWidgetState extends State<LightControlsWidget> {
       _tmpWhiteValue = value.round();
       _changedHere = true;
       ConnectionManager().callService(
-            entity.domain, "turn_on", entity.entityId,
-            {"white_value": _tmpWhiteValue});
+            domain: entity.domain,
+            service: "turn_on",
+            entityId: entity.entityId,
+            data: {"white_value": _tmpWhiteValue}
+          );
 
     });
   }
@@ -50,8 +56,11 @@ class _LightControlsWidgetState extends State<LightControlsWidget> {
       _tmpColorTemp = value.round();
       _changedHere = true;
       ConnectionManager().callService(
-          entity.domain, "turn_on", entity.entityId,
-          {"color_temp": _tmpColorTemp});
+          domain: entity.domain,
+          service: "turn_on",
+          entityId: entity.entityId,
+          data: {"color_temp": _tmpColorTemp}
+        );
     });
   }
 
@@ -59,10 +68,12 @@ class _LightControlsWidgetState extends State<LightControlsWidget> {
     setState(() {
       _tmpColor = color;
       _changedHere = true;
-      Logger.d( "HS Color: [${color.hue}, ${color.saturation}]");
       ConnectionManager().callService(
-        entity.domain, "turn_on", entity.entityId,
-          {"hs_color": [color.hue, color.saturation*100]});
+        domain: entity.domain,
+        service: "turn_on",
+        entityId: entity.entityId,
+        data: {"hs_color": [color.hue, color.saturation*100]}
+      );
     });
   }
 
@@ -72,8 +83,11 @@ class _LightControlsWidgetState extends State<LightControlsWidget> {
       _changedHere = true;
       if (_tmpEffect != null) {
         ConnectionManager().callService(
-            entity.domain, "turn_on", entity.entityId,
-            {"effect": "$value"});
+            domain: entity.domain,
+            service: "turn_on",
+            entityId: entity.entityId,
+            data: {"effect": "$value"}
+          );
       }
     });
   }
diff --git a/lib/entities/lock/widgets/lock_state.dart b/lib/entities/lock/widgets/lock_state.dart
index fe98dbc..58287ca 100644
--- a/lib/entities/lock/widgets/lock_state.dart
+++ b/lib/entities/lock/widgets/lock_state.dart
@@ -7,11 +7,11 @@ class LockStateWidget extends StatelessWidget {
   const LockStateWidget({Key key, this.assumedState: false}) : super(key: key);
 
   void _lock(Entity entity) {
-    ConnectionManager().callService("lock", "lock", entity.entityId, null);
+    ConnectionManager().callService(domain: "lock", service: "lock", entityId: entity.entityId);
   }
 
   void _unlock(Entity entity) {
-    ConnectionManager().callService("lock", "unlock", entity.entityId, null);
+    ConnectionManager().callService(domain: "lock", service: "unlock", entityId: entity.entityId);
   }
 
   @override
diff --git a/lib/entities/media_player/widgets/media_player_seek_bar.widget.dart b/lib/entities/media_player/widgets/media_player_seek_bar.widget.dart
index e3cf446..edfb513 100644
--- a/lib/entities/media_player/widgets/media_player_seek_bar.widget.dart
+++ b/lib/entities/media_player/widgets/media_player_seek_bar.widget.dart
@@ -57,10 +57,10 @@ class _MediaPlayerSeekBarState extends State<MediaPlayerSeekBar> {
               focusColor: Colors.white,
               onPressed: () {
                 ConnectionManager().callService(
-                    "media_player",
-                    "media_seek",
-                    "${entity.entityId}",
-                    {"seek_position": _savedPosition}
+                    domain: "media_player",
+                    service: "media_seek",
+                    entityId: entity.entityId,
+                    data: {"seek_position": _savedPosition}
                 );
                 setState(() {
                   _savedPosition = 0;
@@ -104,10 +104,10 @@ class _MediaPlayerSeekBarState extends State<MediaPlayerSeekBar> {
                 Timer(Duration(milliseconds: 500), () {
                   if (!_seekStarted) {
                     ConnectionManager().callService(
-                        "media_player",
-                        "media_seek",
-                        "${entity.entityId}",
-                        {"seek_position": val}
+                        domain: "media_player",
+                        service: "media_seek",
+                        entityId: entity.entityId,
+                        data: {"seek_position": val}
                     );
                     setState(() {
                       _changedHere = true;
diff --git a/lib/entities/media_player/widgets/media_player_widgets.dart b/lib/entities/media_player/widgets/media_player_widgets.dart
index 9f0290e..fd7e79f 100644
--- a/lib/entities/media_player/widgets/media_player_widgets.dart
+++ b/lib/entities/media_player/widgets/media_player_widgets.dart
@@ -122,13 +122,17 @@ class MediaPlayerPlaybackControls extends StatelessWidget {
       if (entity.state == EntityState.off) {
         Logger.d("${entity.entityId} turn_on");
         ConnectionManager().callService(
-            entity.domain, "turn_on", entity.entityId,
-            null);
+            domain: entity.domain,
+            service: "turn_on",
+            entityId: entity.entityId
+          );
       } else {
         Logger.d("${entity.entityId} turn_off");
         ConnectionManager().callService(
-            entity.domain, "turn_off", entity.entityId,
-            null);
+            domain: entity.domain,
+            service: "turn_off",
+            entityId: entity.entityId
+          );
       }
     }
   }
@@ -136,8 +140,10 @@ class MediaPlayerPlaybackControls extends StatelessWidget {
   void _callAction(MediaPlayerEntity entity, String action) {
     Logger.d("${entity.entityId} $action");
     ConnectionManager().callService(
-        entity.domain, "$action", entity.entityId,
-        null);
+        domain: entity.domain,
+        service: "$action",
+        entityId: entity.entityId
+      );
   }
 
   @override
@@ -264,27 +270,50 @@ class _MediaPlayerControlsState extends State<MediaPlayerControls> {
     setState(() {
       _changedHere = true;
       _newVolumeLevel = value;
-      ConnectionManager().callService("media_player", "volume_set", entityId, {"volume_level": value});
+      ConnectionManager().callService(
+        domain: "media_player",
+        service: "volume_set",
+        entityId: entityId,
+        data: {"volume_level": value}
+      );
     });
   }
 
   void _setVolumeMute(bool isMuted, String entityId) {
-    ConnectionManager().callService("media_player", "volume_mute", entityId, {"is_volume_muted": isMuted});
+    ConnectionManager().callService(
+      domain: "media_player",
+      service: "volume_mute",
+      entityId: entityId,
+      data: {"is_volume_muted": isMuted}
+    );
   }
 
   void _setVolumeUp(String entityId) {
-    ConnectionManager().callService("media_player", "volume_up", entityId, null);
+    ConnectionManager().callService(
+      domain: "media_player",
+      service: "volume_up",
+      entityId: entityId
+    );
   }
 
   void _setVolumeDown(String entityId) {
-    ConnectionManager().callService("media_player", "volume_down", entityId, null);
+    ConnectionManager().callService(
+      domain: "media_player",
+      service: "volume_down",
+      entityId: entityId
+    );
   }
 
   void _setSoundMode(String value, String entityId) {
     setState(() {
       _newSoundMode = value;
       _changedHere = true;
-      ConnectionManager().callService("media_player", "select_sound_mode", entityId, {"sound_mode": "$value"});
+      ConnectionManager().callService(
+        domain: "media_player",
+        service: "select_sound_mode",
+        entityId: entityId,
+        data: {"sound_mode": "$value"}
+      );
     });
   }
 
@@ -292,7 +321,12 @@ class _MediaPlayerControlsState extends State<MediaPlayerControls> {
     setState(() {
       _newSource = source;
       _changedHere = true;
-      ConnectionManager().callService("media_player", "select_source", entityId, {"source": "$source"});
+      ConnectionManager().callService(
+        domain: "media_player",
+        service: "select_source",
+        entityId: entityId,
+        data: {"source": "$source"}
+      );
     });
   }
 
diff --git a/lib/entities/select/widgets/select_state.dart b/lib/entities/select/widgets/select_state.dart
index 8c6f40d..0d9b3d0 100644
--- a/lib/entities/select/widgets/select_state.dart
+++ b/lib/entities/select/widgets/select_state.dart
@@ -11,8 +11,12 @@ class SelectStateWidget extends StatefulWidget {
 class _SelectStateWidgetState extends State<SelectStateWidget> {
 
   void setNewState(domain, entityId, newValue) {
-    ConnectionManager().callService(domain, "select_option", entityId,
-        {"option": "$newValue"});
+    ConnectionManager().callService(
+      domain: domain,
+      service: "select_option",
+      entityId: entityId,
+      data: {"option": "$newValue"}
+    );
   }
 
   @override
diff --git a/lib/entities/slider/widgets/slider_controls.dart b/lib/entities/slider/widgets/slider_controls.dart
index 74faff9..19b9983 100644
--- a/lib/entities/slider/widgets/slider_controls.dart
+++ b/lib/entities/slider/widgets/slider_controls.dart
@@ -18,8 +18,12 @@ class _SliderControlsWidgetState extends State<SliderControlsWidget> {
       _newValue = newValue;
       _changedHere = true;
     });
-    ConnectionManager().callService(domain, "set_value", entityId,
-        {"value": "${newValue.toString()}"});
+    ConnectionManager().callService(
+      domain: domain,
+      service: "set_value",
+      entityId: entityId,
+      data: {"value": "${newValue.toString()}"}
+    );
   }
 
   @override
diff --git a/lib/entities/switch/widget/switch_state.dart b/lib/entities/switch/widget/switch_state.dart
index 2002e3f..73a1d09 100644
--- a/lib/entities/switch/widget/switch_state.dart
+++ b/lib/entities/switch/widget/switch_state.dart
@@ -39,7 +39,10 @@ class _SwitchStateWidgetState extends State<SwitchStateWidget> {
       domain = entity.domain;
     }
     ConnectionManager().callService(
-        domain, (newValue as bool) ? "turn_on" : "turn_off", entity.entityId, null);
+        domain: domain,
+        service: (newValue as bool) ? "turn_on" : "turn_off",
+        entityId: entity.entityId
+      );
   }
 
   @override
diff --git a/lib/entities/text/widgets/text_input_state.dart b/lib/entities/text/widgets/text_input_state.dart
index 9463f45..f82cf15 100644
--- a/lib/entities/text/widgets/text_input_state.dart
+++ b/lib/entities/text/widgets/text_input_state.dart
@@ -26,8 +26,12 @@ class _TextInputStateWidgetState extends State<TextInputStateWidget> {
 
   void setNewState(newValue, domain, entityId) {
     if (validate(newValue, _minLength, _maxLength)) {
-      ConnectionManager().callService(domain, "set_value", entityId,
-          {"value": "$newValue"});
+      ConnectionManager().callService(
+        domain: domain,
+        service: "set_value",
+        entityId: entityId,
+        data: {"value": "$newValue"}
+      );
     } else {
       setState(() {
         _tmpValue = _entityState;
diff --git a/lib/entities/vacuum/widgets/vacuum_controls.dart b/lib/entities/vacuum/widgets/vacuum_controls.dart
index 14212e4..42764de 100644
--- a/lib/entities/vacuum/widgets/vacuum_controls.dart
+++ b/lib/entities/vacuum/widgets/vacuum_controls.dart
@@ -77,10 +77,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:play")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "start",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "start"
             ),
           )
       );
@@ -91,10 +90,9 @@ class VacuumControls extends StatelessWidget {
           icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:play-pause")),
           iconSize: iconSize,
           onPressed: () => ConnectionManager().callService(
-              "vacuum",
-              entity.entityId,
-              "start_pause",
-              null
+              domain: "vacuum",
+              entityId: entity.entityId,
+              service: "start_pause"
           ),
         )
       );
@@ -104,10 +102,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:pause")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "pause",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "pause"
             ),
           )
       );
@@ -118,10 +115,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:stop")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "stop",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "stop"
             ),
           )
       );
@@ -132,10 +128,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:broom")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "clean_spot",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "clean_spot"
             ),
           )
       );
@@ -146,10 +141,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:map-marker")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "locate",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "locate"
             ),
           )
       );
@@ -160,10 +154,9 @@ class VacuumControls extends StatelessWidget {
             icon: Icon(MaterialDesignIcons.getIconDataFromIconName("mdi:home-map-marker")),
             iconSize: iconSize,
             onPressed: () => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "return_to_base",
-                null
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "return_to_base"
             ),
           )
       );
@@ -201,10 +194,10 @@ class VacuumControls extends StatelessWidget {
             options: entity.fanSpeedList,
             value: entity.fanSpeed,
             onChange: (val) => ConnectionManager().callService(
-                "vacuum",
-                entity.entityId,
-                "set_fan_speed",
-                {"fan_speed": val}
+                domain: "vacuum",
+                entityId: entity.entityId,
+                service: "set_fan_speed",
+                data: {"fan_speed": val}
             )
         ),
       );
diff --git a/lib/managers/connection_manager.class.dart b/lib/managers/connection_manager.class.dart
index 2012889..df72960 100644
--- a/lib/managers/connection_manager.class.dart
+++ b/lib/managers/connection_manager.class.dart
@@ -348,16 +348,16 @@ class ConnectionManager {
     _currentMessageId += 1;
   }
 
-  Future callService(String domain, String service, String entityId, Map additionalServiceData) {
+  Future callService({@required String domain, @required String service, String entityId, Map data}) {
     eventBus.fire(NotifyServiceCallEvent(domain, service, entityId));
-    Logger.d("Service call: $domain.$service, $entityId, $additionalServiceData");
+    Logger.d("Service call: $domain.$service, $entityId, $data");
     Completer completer = Completer();
     Map serviceData = {};
     if (entityId != null) {
       serviceData["entity_id"] = entityId;
     }
-    if (additionalServiceData != null && additionalServiceData.isNotEmpty) {
-      serviceData.addAll(additionalServiceData);
+    if (data != null && data.isNotEmpty) {
+      serviceData.addAll(data);
     }
     if (serviceData.isNotEmpty)
       sendHTTPPost(
diff --git a/lib/managers/mobile_app_integration_manager.class.dart b/lib/managers/mobile_app_integration_manager.class.dart
index 6b654e2..e277e2d 100644
--- a/lib/managers/mobile_app_integration_manager.class.dart
+++ b/lib/managers/mobile_app_integration_manager.class.dart
@@ -45,7 +45,7 @@ class MobileAppIntegrationManager {
             positiveText: "Restart now",
             negativeText: "Later",
             onPositive: () {
-              ConnectionManager().callService("homeassistant","restart", null, null);
+              ConnectionManager().callService(domain: "homeassistant", service: "restart");
             },
           ));
         });
diff --git a/lib/pages/integration_settings.page.dart b/lib/pages/integration_settings.page.dart
index c3c3ba4..3fc73e0 100644
--- a/lib/pages/integration_settings.page.dart
+++ b/lib/pages/integration_settings.page.dart
@@ -56,7 +56,7 @@ class _IntegrationSettingsPageState extends State<IntegrationSettingsPage> {
       positiveText: "Sure. Make it so",
       negativeText: "What?? No!",
       onPositive: () {
-        ConnectionManager().callService("homeassistant", "restart", null, null);
+        ConnectionManager().callService(domain: "homeassistant", service: "restart");
       },
     ));
   }
@@ -68,7 +68,7 @@ class _IntegrationSettingsPageState extends State<IntegrationSettingsPage> {
       positiveText: "Sure. Make it so",
       negativeText: "What?? No!",
       onPositive: () {
-        ConnectionManager().callService("homeassistant","stop", null, null);
+        ConnectionManager().callService(domain: "homeassistant", service: "stop");
       },
     ));
   }
diff --git a/lib/pages/play_media.page.dart b/lib/pages/play_media.page.dart
index b6a651b..8eddd4a 100644
--- a/lib/pages/play_media.page.dart
+++ b/lib/pages/play_media.page.dart
@@ -89,21 +89,20 @@ class _PlayMediaPageState extends State<PlayMediaPage> {
       }
       Navigator.pop(context);
       ConnectionManager().callService(
-          serviceDomain,
-          "play_media",
-          entity.entityId,
-          {
-            "media_content_id": _mediaUrl,
-            "media_content_type": _contentType
-          }
+          domain: serviceDomain,
+          service: "play_media",
+          entityId: entity.entityId,
+          data: {
+              "media_content_id": _mediaUrl,
+              "media_content_type": _contentType
+            }
       );
       HomeAssistant().sendToPlayerId = entity.entityId;
       if (HomeAssistant().sendFromPlayerId != null && HomeAssistant().sendFromPlayerId != HomeAssistant().sendToPlayerId) {
         ConnectionManager().callService(
-          HomeAssistant().sendFromPlayerId.split(".")[0],
-          "turn_off",
-          HomeAssistant().sendFromPlayerId,
-          null
+          domain: HomeAssistant().sendFromPlayerId.split(".")[0],
+          service: "turn_off",
+          entityId: HomeAssistant().sendFromPlayerId
         );
         HomeAssistant().sendFromPlayerId = null;
       }