diff --git a/packages/main/src/NPSMessage.js b/packages/main/src/NPSMessage.js
new file mode 100644
index 0000000..cf3f776
--- /dev/null
+++ b/packages/main/src/NPSMessage.js
@@ -0,0 +1,45 @@
+import { NPSMessageHeader } from "./NPSMessageHeader.js";
+import { NPSMessagePayload } from "./NPSMessagePayload.js";
+
+export class NPSMessage {
+  constructor() {
+    this._header = new NPSMessageHeader();
+    this.data = new NPSMessagePayload();
+  }
+  /**
+   *
+   * @param {Buffer} data
+   * @returns {NPSMessage}
+   */
+  static parse(data) {
+    const self = new NPSMessage();
+    if (data.length < 8) {
+      throw new Error(`Invalid message length: ${data.length}`);
+    }
+
+    self._header = NPSMessageHeader.parse(data);
+
+    const expectedLength = self._header.messageLength - self._header.dataOffset;
+
+    self.data = NPSMessagePayload.parse(
+      data.subarray(self._header.dataOffset),
+      expectedLength,
+    );
+
+    return self;
+  }
+
+  /**
+   * @returns Buffer
+   */
+  toBuffer() {
+    return Buffer.concat([this._header.toBuffer(), this.data.toBuffer()]);
+  }
+
+  /**
+   * @returns string
+   */
+  toString() {
+    return `${this._header.toString()}, Data: ${this.data.toString()}`;
+  }
+}
diff --git a/packages/main/src/NPSMessageHeader.js b/packages/main/src/NPSMessageHeader.js
new file mode 100644
index 0000000..eb37b24
--- /dev/null
+++ b/packages/main/src/NPSMessageHeader.js
@@ -0,0 +1,69 @@
+export class NPSMessageHeader {
+  constructor() {
+    this._dataStart = -1;
+    this.messageId = -1;
+    this.messageLength = -1;
+    this.version = -1;
+  }
+
+  /**
+   *
+   * @param {Buffer} data
+   * @returns NPSMessageHeader
+   */
+  static parse(data) {
+    const self = new NPSMessageHeader();
+    if (data.length < 6) {
+      throw new Error("Invalid header length");
+    }
+    self.messageId = data.readUInt16BE(0);
+    self.messageLength = data.readUInt16BE(2);
+
+    self.version = data.readUInt16BE(4);
+
+    if (self.version === 257) {
+      self._dataStart = 12;
+    } else {
+      self._dataStart = 6;
+    }
+
+    return self;
+  }
+
+  get dataOffset() {
+    return this._dataStart;
+  }
+
+  /**
+   * @private
+   * @returns Buffer
+   */
+  _writeExtraData() {
+    const buffer = Buffer.alloc(6);
+    buffer.writeUInt16BE(0, 0);
+    buffer.writeUInt32BE(this.messageLength, 2);
+    return buffer;
+  }
+
+  /**
+   * @returns Buffer
+   */
+  toBuffer() {
+    let buffer = Buffer.alloc(6);
+    buffer.writeUInt16BE(this.messageId, 0);
+    buffer.writeUInt16BE(this.messageLength, 2);
+    buffer.writeUInt16BE(this.version, 4);
+
+    if (this.version === 257) {
+      return Buffer.concat([buffer, this._writeExtraData()]);
+    }
+    return buffer;
+  }
+
+  /**
+   * @returns string
+   */
+  toString() {
+    return `ID: ${this.messageId}, Length: ${this.messageLength}, Version: ${this.version}`;
+  }
+}
diff --git a/packages/main/src/NPSMessagePayload.js b/packages/main/src/NPSMessagePayload.js
new file mode 100644
index 0000000..11dad46
--- /dev/null
+++ b/packages/main/src/NPSMessagePayload.js
@@ -0,0 +1,91 @@
+/**
+ * @interface INPSPayload
+ */
+/**
+ * @interface INPSPayload
+ * @static parse
+ * @property {Buffer} data
+ */
+export class INPSPayload {
+  constructor() {
+    this.data = Buffer.alloc(0);
+    this.toBuffer = function () {};
+    this.toString = function () {};
+  }
+
+  /**
+   * @param {Buffer} data
+   * @returns INPSPayload
+   */
+  static parse(data) {
+    const self = new NPSMessagePayload();
+    self.data = data;
+    return self;
+  }
+}
+
+/**
+ * To be used as a base class for NPS message payloads.
+ *
+ * @implements {INPSPayload}
+ * @class
+ * @property {Buffer} data
+ *
+ * @example
+ * class MyPayload extends NPSMessagePayload {
+ *  constructor() {
+ *      super();
+ *      this.myProperty = 0;
+ *  }
+ *
+ *  static parse(data) {
+ *      this.myProperty = data.readUInt32LE(0);
+ *  }
+ *
+ *  toBuffer() {
+ *      const buffer = Buffer.alloc(4);
+ *      buffer.writeUInt32LE(this.myProperty, 0);
+ *      return buffer;
+ *  }
+ *
+ *  toString() {
+ *      return `MyPayload: ${this.myProperty}`;
+ *  }
+ * }
+ */
+
+export class NPSMessagePayload {
+  constructor() {
+    this.data = Buffer.alloc(0);
+  }
+
+  /**
+   *
+   * @param {Buffer} data
+   * @returns NPSMessagePayload
+   */
+  static parse(data, len = data.length) {
+    if (data.length !== len) {
+      throw new Error(
+        `Invalid payload length: ${data.length}, expected: ${len}`,
+      );
+    }
+    const self = new NPSMessagePayload();
+    self.data = data;
+    return self;
+  }
+
+  /**
+   * @returns Buffer
+   */
+  toBuffer() {
+    return this.data;
+  }
+
+  /**
+   * @returns string
+   */
+  toString() {
+    return this.data.toString("hex");
+  }
+}
diff --git a/packages/main/src/NPSUserLoginPayload.js b/packages/main/src/NPSUserLoginPayload.js
new file mode 100644
index 0000000..3b99c89
--- /dev/null
+++ b/packages/main/src/NPSUserLoginPayload.js
@@ -0,0 +1,73 @@
+import { NPSMessagePayload } from "./NPSMessagePayload.js";
+
+/**
+ * @typedef INPSPayload
+ * @type {import("./NPSMessagePayload.js").INPSPayload}
+ */
+
+/**
+ * @implements {INPSPayload}
+ * @extends {NPSMessagePayload}
+ * Payload for the NPSUserLogin message.
+ */
+export class NPSUserLoginPayload extends NPSMessagePayload {
+  constructor() {
+    super();
+    this.data = Buffer.alloc(0);
+    this.ticket = "";
+    this.sessionKey = "";
+    this.gameId = "";
+  }
+
+  /**
+   *
+   * @param {number} len
+   * @param {Buffer} data
+   * @returns {NPSUserLoginPayload}
+   */
+  static parse(data, len = data.length) {
+    if (data.length !== len) {
+      throw new Error(
+        `Invalid payload length: ${data.length}, expected: ${len}`,
+      );
+    }
+
+    const self = new NPSUserLoginPayload();
+    try {
+      let offset = 0;
+      let nextLen = data.readUInt16BE(0);
+      self.ticket = data.toString("utf8", 2, nextLen + 2);
+      offset = nextLen + 2;
+      offset += 2; // Skip one empty word
+      nextLen = data.readUInt16BE(offset);
+      self.sessionKey = data.toString("hex", offset + 2, offset + 2 + nextLen);
+      offset += nextLen + 2;
+      nextLen = data.readUInt16BE(offset);
+      self.gameId = data
+        .subarray(offset + 2, offset + 2 + nextLen)
+        .toString("utf8");
+    } catch (error) {
+      if (!(error instanceof Error)) {
+        throw new Error(`Error parsing payload: ${error}`);
+      }
+      console.error(`Error parsing payload: ${error.message}`);
+      throw new Error(`Error parsing payload: ${error.message}`);
+    }
+
+    return self;
+  }
+
+  /**
+   * @returns {Buffer}
+   */
+  toBuffer() {
+    throw new Error("Method not implemented.");
+  }
+
+  /**
+   * @returns {string}
+   */
+  toString() {
+    return `Ticket: ${this.ticket}, SessionKey: ${this.sessionKey}, GameId: ${this.gameId}`;
+  }
+}
diff --git a/packages/main/src/index.js b/packages/main/src/index.js
index 454a323..e413578 100644
--- a/packages/main/src/index.js
+++ b/packages/main/src/index.js
@@ -21,6 +21,8 @@ import { UserLoginService } from "./UserLoginService.js";
 import { WebServer } from "./WebServer.js";
 import { onNPSData } from "./nps.js";
 import { onWebRequest } from "./web.js";
+import crypto from "node:crypto";
+import * as Sentry from "@sentry/node";
 
 /** @type {WebServer} */
 let authServer;
@@ -33,12 +35,21 @@ let personaServer;
 
 /**
  * @param {import("node:net").Socket} socket
- * @param {(port:number, data: Buffer) => void} onData
+ * @param {(port:number, data: Buffer, sendToClient: (data: Buffer) => void) => void} onData
  */
 function onSocketConnection(socket, onData) {
   console.log("Connection established");
+
+  const connectionId = crypto.randomUUID();
+
+  Sentry.setTag("connection_id", connectionId);
+
+  const sendToClient = (/** @type {Buffer} */ data) => {
+    socket.write(data);
+  };
+
   socket.on("data", (data) => {
-    onData(socket.localPort ?? -1, data);
+    onData(socket.localPort ?? -1, data, sendToClient);
   });
 }
 
@@ -133,7 +144,7 @@ export default function main() {
     "Rusty Motors",
     "A test shard",
     "10.10.5.20",
-    "Group - 1"
+    "Group - 1",
   );
 
   const userLoginService = new UserLoginService();
diff --git a/packages/main/src/nps.js b/packages/main/src/nps.js
index 0e4dd49..302ffdf 100644
--- a/packages/main/src/nps.js
+++ b/packages/main/src/nps.js
@@ -1,8 +1,36 @@
+import { NPSMessage } from "./NPSMessage.js";
+import { NPSUserLoginPayload } from "./NPSUserLoginPayload.js";
+
+/**
+ * @typedef INPSPayload
+ * @type {import("./NPSMessagePayload.js").INPSPayload}
+ */
+
+/** @type {Map<number, (data: Buffer, len: number) => INPSPayload>} */
+const payloadMap = new Map();
+
+payloadMap.set(1281, NPSUserLoginPayload.parse);
+
 /**
  * @param {number} port
  * @param {Buffer} data
+ * @param {(data: Buffer) => void} sendToClient
  */
-export function onNPSData(port, data) {
-  const hex = data.toString("hex");
-  console.log(`Data received: ${hex}`);
+export function onNPSData(port, data, sendToClient) {
+  const message = NPSMessage.parse(data);
+  console.log(`Received message on port ${port}: ${message.toString()}`);
+
+  const messageType = payloadMap.get(message._header.messageId);
+
+  if (!messageType) {
+    console.error(`Unknown message type: ${message._header.messageId}`);
+    return;
+  }
+
+  const payload = messageType(
+    message.data.data,
+    message._header.messageLength - message._header.dataOffset,
+  );
+
+  console.log(`Parsed payload: ${payload.toString()}`);
 }