diff --git a/6.ts b/6.ts
index 651fc82..c1bb5cb 100644
--- a/6.ts
+++ b/6.ts
@@ -2,6 +2,30 @@ import { BufReader } from "https://deno.land/std@0.157.0/io/buffer.ts";
 
 const PORT = 5588;
 
+type Road = number;
+type Dispatcher = Road[];
+type Location = number;
+type SpeedLimit = number;
+type Timestamp = number;
+type Plate = string;
+type Car = Plate;
+
+type U8 = number;
+type U16 = number;
+type U32 = number;
+
+interface Camera {
+  road: Road;
+  location: Location;
+  speedLimit: SpeedLimit;
+}
+
+interface Report {
+  camera: Camera;
+  car: Car;
+  timestamp: Timestamp;
+}
+
 // const tEnc = new TextEncoder();
 
 console.log(`Starting TCP listener on on 0.0.0.0:${PORT}`);
@@ -19,11 +43,32 @@ function chatSession(conn: Deno.Conn) {
   serve(conn).catch((e) => e).finally(closeOnDisconnect);
 }
 
+enum MessageType {
+  ERROR = 0x10, // Server -> Client
+  PLATE = 0x20, // Client -> Server
+  TICKET = 0x21, // Server -> Client
+}
+
+type ErrorMessage = [
+  string, // msg
+];
+
+type PlateMessage = [
+  string, // plate
+  U32, // timestamp
+];
+
+interface TicketMessage {
+}
+
+type Message = ErrorMessage | PlateMessage;
+
 async function serve(conn: Deno.Conn) {
   const reader = new BufReader(conn);
   const type = await reader.peek(1);
   if (!type) throw new Error("failed to peek start of packet");
-  console.log(type);
+  console.log({ type }, 0x64);
+  // TODO: loop...
 }
 
 for await (const conn of Deno.listen({ port: PORT })) {