diff --git a/kennel/engine/components/component.py b/kennel/engine/components/component.py
index c8ef2d0..da55138 100644
--- a/kennel/engine/components/component.py
+++ b/kennel/engine/components/component.py
@@ -12,5 +12,5 @@ class Component:
         self.component_type = component_type
 
     @abstractmethod
-    def dict(self) -> dict:
+    def to_dict(self) -> dict:
         pass
diff --git a/kennel/engine/components/controllable.py b/kennel/engine/components/controllable.py
index 25ec835..a9173af 100644
--- a/kennel/engine/components/controllable.py
+++ b/kennel/engine/components/controllable.py
@@ -9,6 +9,6 @@ class Controllable(Component):
     def __repr__(self) -> str:
         return f"Controllable(by={self.by})"
 
-    def dict(self) -> dict:
+    def to_dict(self) -> dict:
         # don't serialize who owns this
         return {}
diff --git a/kennel/engine/components/position.py b/kennel/engine/components/position.py
index 2a4da4a..5c5b372 100644
--- a/kennel/engine/components/position.py
+++ b/kennel/engine/components/position.py
@@ -10,5 +10,5 @@ class Position(Component):
     def __repr__(self) -> str:
         return f"Position(x={self.x}, y={self.y})"
 
-    def dict(self) -> dict:
+    def to_dict(self) -> dict:
         return {"x": self.x, "y": self.y}
diff --git a/kennel/engine/entities/entity.py b/kennel/engine/entities/entity.py
index 6623512..1d8c34d 100644
--- a/kennel/engine/entities/entity.py
+++ b/kennel/engine/entities/entity.py
@@ -27,7 +27,7 @@ class Entity:
         return {
             "entity_type": self.entity_type,
             "id": self.id,
-            "components": {k: v.dict() for k, v in self.components.items()},
+            "components": {k: v.to_dict() for k, v in self.components.items()},
         }
 
 
diff --git a/kennel/engine/systems/network.py b/kennel/engine/systems/network.py
index c9696c8..8dbf4cf 100644
--- a/kennel/engine/systems/network.py
+++ b/kennel/engine/systems/network.py
@@ -1,15 +1,17 @@
 from enum import Enum
-from kennel.engine.entities.entity import EntityManager
+from kennel.engine.entities.entity import Entity, EntityType, EntityManager
 from .system import System, SystemType
 from abc import abstractmethod
+from typing import Optional, List
 import asyncio
 
 
 class EventType(str, Enum):
     INITIAL_STATE = "INITIAL_STATE"
+    SET_CONTROLLABLE = "SET_CONTROLLABLE"
     ENTITY_BORN = "ENTITY_BORN"
-    ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE"
     ENTITY_DEATH = "ENTITY_DEATH"
+    ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE"
 
 
 class Event:
@@ -17,29 +19,86 @@ class Event:
         self.event_type = event_type
         self.data = data
 
-    def __str__(self):
+    def __str__(self) -> str:
         return f"Event({self.event_type}, {self.data})"
 
-    def dict(self):
+    def to_dict(self) -> dict:
         return {"event_type": self.event_type, "data": self.data}
 
     @staticmethod
-    def from_dict(data: dict):
+    def from_dict(data: dict) -> Optional["Event"]:
+        if "event_type" not in data or "data" not in data:
+            return
+        event_type = data["event_type"]
+        if event_type == EventType.INITIAL_STATE:
+            return InitialStateEvent(
+                data["data"]["world"]["width"],
+                data["data"]["world"]["height"],
+                data["data"]["entities"],
+            )
+        if event_type == EventType.SET_CONTROLLABLE:
+            return SetControllableEvent(data["data"]["id"], data["data"]["client_id"])
+        if event_type == EventType.ENTITY_BORN:
+            return EntityBornEvent(data["data"])
+        if event_type == EventType.ENTITY_POSITION_UPDATE:
+            return EntityPositionUpdateEvent(
+                data["data"]["id"], data["data"]["position"]
+            )
+        if event_type == EventType.ENTITY_DEATH:
+            return EntityDeathEvent(data["data"]["id"])
+
+        logger.warn(f"Unknown event type: {data['event_type']}")
         return Event(EventType(data["event_type"]), data["data"])
 
 
+class InitialStateEvent(Event):
+    def __init__(self, world_width: int, world_height: int, entities: List[Entity]):
+        self.world_width = world_width
+        self.world_height = world_height
+        self.entities = entities
+        super().__init__(
+            EventType.INITIAL_STATE,
+            {
+                "world": {"width": world_width, "height": world_height},
+                "entities": [entity.to_dict() for entity in entities],
+            },
+        )
+
+
+class SetControllableEvent(Event):
+    def __init__(self, entity_id: str, client_id: str):
+        self.entity_id = entity_id
+        self.client_id = client_id
+        super().__init__(
+            EventType.SET_CONTROLLABLE, {"id": entity_id, "client_id": client_id}
+        )
+
+
+class EntityBornEvent(Event):
+    def __init__(self, entity: Entity):
+        self.entity = entity
+        super().__init__(EventType.ENTITY_BORN, {"entity": entity.to_dict()})
+
+
+class EntityPositionUpdateEvent(Event):
+    def __init__(self, entity_id: str, position: dict):
+        super().__init__(
+            EventType.ENTITY_POSITION_UPDATE,
+            {"id": entity_id, "position": position},
+        )
+
+
+class EntityDeathEvent(Event):
+    def __init__(self, entity_id: str):
+        super().__init__(EventType.ENTITY_DEATH, {"id": entity_id})
+
+
 class Publishable:
     @abstractmethod
     async def publish(self, event: Event):
         pass
 
 
-class ClientEventTransformer:
-    @abstractmethod
-    def apply(self, event: Event) -> Event:
-        pass
-
-
 class EventProcessor:
     @abstractmethod
     def accept(self, entity_manager: EntityManager, event: Event) -> None:
@@ -47,37 +106,32 @@ class EventProcessor:
 
 
 class NetworkSystem(System):
-    def __init__(
-        self,
-        event_processor: EventProcessor,
-        client_event_transformer: ClientEventTransformer,
-    ):
+    def __init__(self, event_processor: EventProcessor):
         super().__init__(SystemType.NETWORK)
         self.event_processor = event_processor
-        self.client_event_transformer = client_event_transformer
 
         self.events = []
+        self.client_events = []
         self.clients = {}
 
     async def update(self, entity_manager: EntityManager, delta_time: float) -> None:
-        for event in self.events:
+        if len(self.events) + len(self.client_events) == 0:
+            return
+        for event in self.events + self.client_events:
             self.event_processor.accept(entity_manager, event)
-        client_events = [
-            self.client_event_transformer.apply(entity_manager, event)
-            for event in self.events
-        ]
+        client_sendable = self.events + [event for event, _ in self.client_events]
         await asyncio.gather(
             *[
                 client.publish(event)
                 for client in self.clients.values()
-                for event in client_events
+                for event in client_sendable
             ]
         )
         self.events = []
+        self.client_events = []
 
     def client_event(self, client_id: str, event: Event) -> None:
-        event.data["client_id"] = client_id
-        self.events.append(event)
+        self.client_events.append((event, client_id))
 
     def add_event(self, event: Event) -> None:
         self.events.append(event)
diff --git a/kennel/kennel.py b/kennel/kennel.py
index 61847a5..bb0438c 100644
--- a/kennel/kennel.py
+++ b/kennel/kennel.py
@@ -6,7 +6,6 @@ from kennel.engine.systems.system import SystemManager
 from kennel.engine.systems.network import (
     NetworkSystem,
     EventProcessor,
-    ClientEventTransformer,
     Event,
     EventType,
 )
@@ -21,28 +20,33 @@ system_manager = SystemManager()
 
 
 class KennelEventProcessor(EventProcessor):
-    def accept(self, entity_manager: EntityManager, event: Event) -> None:
+    def accept(
+        self, entity_manager: EntityManager, event: type[Event | tuple[Event, str]]
+    ) -> None:
+        if isinstance(event, tuple):
+            client_event, client_id = event
+            self._process_client_event(entity_manager, client_event, client_id)
+            return
+
+    def _process_client_event(
+        self, entity_manager: EntityManager, event: Event, client_id: str
+    ) -> None:
         if event.event_type == EventType.ENTITY_POSITION_UPDATE:
-            self._process_entity_position_update(entity_manager, event)
+            self._process_entity_position_update(entity_manager, event, client_id)
 
     def _process_entity_position_update(
-        self, entity_manager: EntityManager, event: Event
+        self, entity_manager: EntityManager, event: Event, client_id: str
     ) -> None:
-        entity = entity_manager.get_entity(event.data["entity_id"])
+        entity = entity_manager.get_entity(event.data["id"])
         if entity is None:
-            logger.error(f"Entity {event.data['entity_id']} does not exist")
-            return
-        if event.data["client_id"] is None:
-            logger.error("Client ID is required for position updates")
+            logger.error(f"Entity(id={event.data['id']}) does not exist")
             return
         controllable = entity.get_component(ComponentType.CONTROLLABLE)
         if controllable is None:
             logger.error(f"Entity {entity} is not controllable")
             return
-        if controllable.by != event.data["client_id"]:
-            logger.error(
-                f"Entity {entity} is not controllable by client {event.data['client_id']}"
-            )
+        if controllable.by != client_id:
+            logger.error(f"Entity {entity} is not controllable by client {client_id}")
             return
         position = entity.get_component(ComponentType.POSITION)
         if position is None:
@@ -51,30 +55,14 @@ class KennelEventProcessor(EventProcessor):
         entity.add_component(position)
 
 
-class KennelClientEventTransformer(ClientEventTransformer):
-    def apply(self, entity_manager: EntityManager, event: Event) -> Event:
-        if event.event_type == EventType.ENTITY_BORN:
-            id = event.data["id"]
-            entity = entity_manager.get_entity(id)
-            if entity is None:
-                logger.error(f"Entity {id} does not exist")
-                return event
-            for component_type in entity.components:
-                component = entity.get_component(component_type)
-                if component is not None:
-                    event.data[component_type] = component.dict()
-
-        return event
-
-
 system_manager.add_system(WorldSystem(config.WORLD_WIDTH, config.WORLD_HEIGHT))
 system_manager.add_system(
-    NetworkSystem(EventProcessor(), KennelClientEventTransformer()),
+    NetworkSystem(KennelEventProcessor()),
 )
 
 kennel = Game(entity_manager, system_manager, config.MIN_TIME_STEP)
 
 
 def create_session_controllable_entities(session: str) -> List[Entity]:
-    laser = Laser(uuid.uuid4().hex, session)
+    laser = Laser(uuid.uuid4().hex[:10], session)
     return [laser]
diff --git a/kennel/main.py b/kennel/main.py
index 6f661cb..fc0fd0e 100644
--- a/kennel/main.py
+++ b/kennel/main.py
@@ -11,7 +11,14 @@ from fastapi import (
 from fastapi.responses import FileResponse
 from fastapi.staticfiles import StaticFiles
 from kennel.engine.systems.system import SystemType
-from kennel.engine.systems.network import Event, Publishable, EventType
+from kennel.engine.systems.network import (
+    Event,
+    Publishable,
+    EventType,
+    InitialStateEvent,
+    SetControllableEvent,
+    EntityBornEvent,
+)
 from typing import Annotated, Optional
 from kennel.kennel import (
     kennel,
@@ -76,7 +83,7 @@ class WebSocketClient(Publishable):
         self.websocket = websocket
 
     async def publish(self, event: Event):
-        await self.websocket.send_json(event.dict())
+        await self.websocket.send_json([event.event_type, event.data])
 
 
 @app.websocket("/ws")
@@ -85,19 +92,16 @@ async def websocket_endpoint(
     session: Annotated[str, Depends(get_cookie_or_token)],
 ):
     await websocket.accept()
+    client = WebSocketClient(websocket)
     logger.info(f"Websocket connection established for session {session}")
 
-    await websocket.send_json(
-        {
-            "event_type": EventType.INITIAL_STATE,
-            "data": {
-                "world": {"width": config.WORLD_WIDTH, "height": config.WORLD_HEIGHT},
-                "entities": kennel.entity_manager.to_dict(),
-            },
-        }
+    initial_state = InitialStateEvent(
+        config.WORLD_WIDTH, config.WORLD_HEIGHT, kennel.entity_manager.to_dict()
     )
+    await client.publish(initial_state)
 
     session_entities = create_session_controllable_entities(session)
+    logger.info(f"Creating {len(session_entities)} entities for session {session}")
     try:
         network_system = system_manager.get_system(SystemType.NETWORK)
         if network_system is None:
@@ -106,14 +110,26 @@ async def websocket_endpoint(
         for entity in session_entities:
             logger.info(f"Adding entity {entity.id} for session {session}")
             entity_manager.add_entity(entity)
-            network_system.add_event(Event(EventType.ENTITY_BORN, {"id": entity.id}))
+            network_system.add_event(EntityBornEvent(entity))
+
+            set_controllable_event = SetControllableEvent(entity.id, session)
+            await client.publish(set_controllable_event)
 
         network_system.add_client(session, WebSocketClient(websocket))
         while True:
             message = await websocket.receive_json()
-            network_system.client_event(session, Event.from_dict(message))
+            if type(message) is not list:
+                message = [message]
+            events = [Event.from_dict(event) for event in message]
+            if not all([event is not None for event in events]):
+                logger.info(f"Invalid events in: {message}"[:100])
+                continue
+            for event in events:
+                network_system.client_event(session, event)
+    except WebSocketDisconnect as e:
+        logger.info(f"Websocket connection closed by client: {session}")
     except Exception as e:
-        logger.error(f"WebSocket exception {e}")
+        logger.error("Exception occurred", exc_info=e)
     finally:
         logger.info("Websocket connection closed")
         for entity in session_entities:
diff --git a/static/src/component.ts b/static/src/component.ts
new file mode 100644
index 0000000..d338cad
--- /dev/null
+++ b/static/src/component.ts
@@ -0,0 +1,8 @@
+export enum ComponentType {
+  POSITION = "POSITION",
+  RENDERABLE = "RENDERABLE",
+}
+
+export interface Component {
+  name: string;
+}
diff --git a/static/src/entity.ts b/static/src/entity.ts
new file mode 100644
index 0000000..811d05a
--- /dev/null
+++ b/static/src/entity.ts
@@ -0,0 +1,11 @@
+import type { Component } from "./component";
+
+export enum EntityType {
+  LASER = "LASER",
+}
+
+export interface Entity {
+  entity_type: EntityType;
+  id: string;
+  components: Record<string, Component>;
+}
diff --git a/static/src/event.ts b/static/src/event.ts
new file mode 100644
index 0000000..cd50122
--- /dev/null
+++ b/static/src/event.ts
@@ -0,0 +1,28 @@
+export enum EventType {
+  INITIAL_STATE = "INITIAL_STATE",
+  SET_CONTROLLABLE = "SET_CONTROLLABLE",
+  ENTITY_BORN = "ENTITY_BORN",
+  ENTITY_DEATH = "ENTITY_DEATH",
+  ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE",
+}
+
+export interface Event {
+  event_type: EventType;
+  data: any;
+}
+
+export interface InitialStateEvent extends Event {
+  event_type: EventType.INITIAL_STATE;
+  data: {
+    world: { width: number; height: number };
+    entities: any[];
+  };
+}
+
+export interface SetControllableEvent extends Event {
+  event_type: EventType.SET_CONTROLLABLE;
+  data: {
+    id: string;
+    client_id: string;
+  };
+}
diff --git a/static/src/main.ts b/static/src/main.ts
index 8d12587..fc04b72 100644
--- a/static/src/main.ts
+++ b/static/src/main.ts
@@ -1,18 +1,51 @@
 import $ from "jquery";
+import { Vec2 } from "./vector";
+import { EventType, type SetControllableEvent, type Event } from "./event";
+import { MouseController } from "./mouse_controller";
 
 $(document).ready(async () => {
-  await fetch("/assign", {
+  const session_id = await fetch("/assign", {
     credentials: "include",
+  })
+    .then((res) => res.json())
+    .then(({ session }) => session);
+
+  const controllable_entities = new Set<string>();
+  const control_callback = (movement: Vec2) => {
+    for (const id of controllable_entities) {
+      const message = JSON.stringify({
+        event_type: EventType.ENTITY_POSITION_UPDATE,
+        data: { id, position: movement },
+      });
+      ws.send(message);
+    }
+  };
+  const mouse_controller = new MouseController(control_callback);
+  $(document).on("mousemove", (event) => {
+    mouse_controller.move(event.clientX, event.clientY);
   });
+  mouse_controller.start();
 
   const ws = new WebSocket("/ws");
-  ws.onopen = () => {
-    console.log("connected");
-  };
+  await new Promise<void>((resolve) => {
+    ws.onopen = () => {
+      console.log("connected");
+      resolve();
+    };
+  });
   ws.onmessage = ({ data }) => {
-    console.log(JSON.parse(data));
+    const [event_type, event_data] = JSON.parse(data);
+    const message = { event_type, data: event_data } as Event;
+
+    console.log("Received message", message);
+    if (message.event_type === EventType.SET_CONTROLLABLE) {
+      const event = message as SetControllableEvent;
+      if (event.data.client_id === session_id) {
+        controllable_entities.add(event.data.id);
+      }
+    }
   };
-  ws.onclose = (e) => {
-    console.log("disconnected", e);
+  ws.onclose = () => {
+    controllable_entities.clear();
   };
 });
diff --git a/static/src/mouse_controller.ts b/static/src/mouse_controller.ts
new file mode 100644
index 0000000..b8849b4
--- /dev/null
+++ b/static/src/mouse_controller.ts
@@ -0,0 +1,54 @@
+import { Vec2 } from "./vector";
+
+export class MouseController {
+  private readonly debounce_ms = 400;
+  private readonly movement_threshold = 40;
+  private last_event_time = Date.now();
+  private movement_queue: Vec2[] = [];
+  private interval_id: number | null = null;
+
+  constructor(private readonly callback: (new_movement: Vec2) => void) {}
+
+  public start() {
+    if (this.interval_id !== null) {
+      return;
+    }
+    this.interval_id = setInterval(() => {
+      this.publish_movement();
+    }, this.debounce_ms);
+  }
+
+  public stop() {
+    if (this.interval_id === null) {
+      return;
+    }
+    clearInterval(this.interval_id);
+    this.interval_id = null;
+  }
+
+  public move(x: number, y: number) {
+    const new_movement = new Vec2(x, y);
+    const last_movement = this.movement_queue.at(-1);
+    this.movement_queue.push(new_movement);
+    if (
+      typeof last_movement === "undefined" ||
+      new_movement.distance_to(last_movement) < this.movement_threshold
+    ) {
+      return;
+    }
+    this.publish_movement();
+  }
+
+  private publish_movement() {
+    if (
+      Date.now() - this.last_event_time < this.debounce_ms ||
+      this.movement_queue.length === 0
+    ) {
+      return;
+    }
+
+    this.last_event_time = Date.now();
+    this.callback(this.movement_queue.at(-1)!);
+    this.movement_queue = [];
+  }
+}
diff --git a/static/src/vector.ts b/static/src/vector.ts
new file mode 100644
index 0000000..e7be9fa
--- /dev/null
+++ b/static/src/vector.ts
@@ -0,0 +1,10 @@
+export class Vec2 {
+  constructor(
+    private readonly x: number,
+    private readonly y: number,
+  ) {}
+
+  public distance_to(that: Vec2): number {
+    return Math.sqrt((this.x - that.x) ** 2 + (this.y - that.y) ** 2);
+  }
+}
diff --git a/static/tsconfig.json b/static/tsconfig.json
index 0511b9f..8f3e483 100644
--- a/static/tsconfig.json
+++ b/static/tsconfig.json
@@ -1,9 +1,9 @@
 {
   "compilerOptions": {
-    "target": "ES2020",
+    "target": "ES2022",
     "useDefineForClassFields": true,
     "module": "ESNext",
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "skipLibCheck": true,
 
     /* Bundler mode */