diff --git a/src/bot/manager.ts b/src/bot/manager.ts
index 9768e21..02f43c3 100644
--- a/src/bot/manager.ts
+++ b/src/bot/manager.ts
@@ -85,6 +85,8 @@ export class BotManager {
       defaultChannel: params.defaultChannel ?? "",
       channelPassword: params.channelPassword ?? "",
       autoStart: params.autoStart ?? false,
+      serverProtocol: params.serverProtocol ?? "",
+      ts6ApiKey: params.ts6ApiKey ?? "",
     });
 
     this.logger.info({ botId: id, name: params.name }, "Bot instance created");
@@ -114,6 +116,8 @@ export class BotManager {
       nickname: params.nickname ?? existing.nickname,
       defaultChannel: params.defaultChannel ?? existing.defaultChannel,
       channelPassword: params.channelPassword ?? existing.channelPassword,
+      serverProtocol: params.serverProtocol ?? existing.serverProtocol,
+      ts6ApiKey: params.ts6ApiKey ?? existing.ts6ApiKey,
     });
     // Update in-memory name immediately (other fields need reconnect)
     const bot = this.bots.get(id);
@@ -150,17 +154,19 @@ export class BotManager {
   async loadSavedBots(): Promise<void> {
     const savedInstances = this.database.getBotInstances();
     for (const saved of savedInstances) {
+      const proto = saved.serverProtocol as "ts3" | "ts6" | "" | undefined;
       const bot = new BotInstance({
         id: saved.id,
         name: saved.name,
         tsOptions: {
           host: saved.serverAddress,
           port: saved.serverPort,
-          queryPort: 10011, // Will be overridden by auto-detection for TS6
+          queryPort: proto === "ts6" ? 10080 : 10011,
           nickname: saved.nickname,
           defaultChannel: saved.defaultChannel || undefined,
           channelPassword: saved.channelPassword || undefined,
-          // Protocol will be auto-detected on connect
+          serverProtocol: proto === "ts3" || proto === "ts6" ? proto : undefined,
+          ts6ApiKey: saved.ts6ApiKey || undefined,
         },
         neteaseProvider: this.neteaseProvider,
         qqProvider: this.qqProvider,
diff --git a/src/data/database.test.ts b/src/data/database.test.ts
index 51da01a..8807797 100644
--- a/src/data/database.test.ts
+++ b/src/data/database.test.ts
@@ -60,6 +60,8 @@ describe("database", () => {
       defaultChannel: "Music",
       channelPassword: "",
       autoStart: true,
+      serverProtocol: "",
+      ts6ApiKey: "",
     };
 
     botDb.saveBotInstance(instance);
@@ -86,6 +88,8 @@ describe("database", () => {
       defaultChannel: "Music",
       channelPassword: "",
       autoStart: false,
+      serverProtocol: "",
+      ts6ApiKey: "",
     });
 
     expect(botDb.deleteBotInstance("bot1")).toBe(true);
diff --git a/src/data/database.ts b/src/data/database.ts
index 8f043ba..5a3ad84 100644
--- a/src/data/database.ts
+++ b/src/data/database.ts
@@ -24,6 +24,10 @@ export interface BotInstance {
   defaultChannel: string;
   channelPassword: string;
   autoStart: boolean;
+  /** "ts3" | "ts6" | "" (empty = auto-detect) */
+  serverProtocol: string;
+  /** API key for TS6 HTTP Query */
+  ts6ApiKey: string;
 }
 
 export interface BotDatabase {
@@ -58,7 +62,9 @@ function initTables(db: Database.Database): void {
       nickname TEXT NOT NULL,
       defaultChannel TEXT NOT NULL,
       channelPassword TEXT NOT NULL,
-      autoStart INTEGER NOT NULL DEFAULT 0
+      autoStart INTEGER NOT NULL DEFAULT 0,
+      serverProtocol TEXT NOT NULL DEFAULT '',
+      ts6ApiKey TEXT NOT NULL DEFAULT ''
     );
   `);
 }
@@ -78,8 +84,8 @@ export function createDatabase(dbPath: string): BotDatabase {
   `);
 
   const upsertInstance = db.prepare(`
-    INSERT INTO bot_instances (id, name, serverAddress, serverPort, nickname, defaultChannel, channelPassword, autoStart)
-    VALUES (@id, @name, @serverAddress, @serverPort, @nickname, @defaultChannel, @channelPassword, @autoStart)
+    INSERT INTO bot_instances (id, name, serverAddress, serverPort, nickname, defaultChannel, channelPassword, autoStart, serverProtocol, ts6ApiKey)
+    VALUES (@id, @name, @serverAddress, @serverPort, @nickname, @defaultChannel, @channelPassword, @autoStart, @serverProtocol, @ts6ApiKey)
     ON CONFLICT(id) DO UPDATE SET
       name = excluded.name,
       serverAddress = excluded.serverAddress,
@@ -87,7 +93,9 @@ export function createDatabase(dbPath: string): BotDatabase {
       nickname = excluded.nickname,
       defaultChannel = excluded.defaultChannel,
       channelPassword = excluded.channelPassword,
-      autoStart = excluded.autoStart
+      autoStart = excluded.autoStart,
+      serverProtocol = excluded.serverProtocol,
+      ts6ApiKey = excluded.ts6ApiKey
   `);
 
   const selectInstances = db.prepare(`SELECT * FROM bot_instances`);
diff --git a/src/ts-protocol/client.ts b/src/ts-protocol/client.ts
index 5bded0d..bf574e6 100644
--- a/src/ts-protocol/client.ts
+++ b/src/ts-protocol/client.ts
@@ -53,6 +53,7 @@ export class TS3Client extends EventEmitter {
   private disconnecting = false;
   private detectedProtocol: ServerProtocol = "unknown";
   private httpQuery: TS6HttpQuery | null = null;
+  private udpErrorTimer: ReturnType<typeof setTimeout> | null = null;
 
   constructor(private options: TS3ClientOptions, logger: Logger) {
     super();
@@ -118,6 +119,14 @@ export class TS3Client extends EventEmitter {
       });
     }
 
+    // Guard against calling connect() while already connected
+    if (this.client) {
+      this.logger.warn("connect() called while already connected, disconnecting first");
+      this.disconnect();
+      // Give the old client a moment to tear down
+      await new Promise((r) => setTimeout(r, 100));
+    }
+
     this.logger.info(
       { addr, protocol: this.detectedProtocol },
       "Connecting to TeamSpeak server (full client protocol)",
@@ -125,19 +134,18 @@ export class TS3Client extends EventEmitter {
 
     // Throttle repeated "udp send error" warnings (fires every 20ms during playback if UDP breaks)
     let udpErrorCount = 0;
-    let udpErrorTimer: ReturnType<typeof setTimeout> | null = null;
     const throttledWarn = (msg: string, ...args: unknown[]) => {
       if (typeof msg === "string" && msg.includes("udp send error")) {
         udpErrorCount++;
         if (udpErrorCount === 1) {
           this.logger.warn(msg);
           // After 2 seconds, log a summary and reset
-          udpErrorTimer = setTimeout(() => {
+          this.udpErrorTimer = setTimeout(() => {
             if (udpErrorCount > 1) {
               this.logger.warn(`udp send error (repeated ${udpErrorCount} times, connection may be lost)`);
             }
             udpErrorCount = 0;
-            udpErrorTimer = null;
+            this.udpErrorTimer = null;
           }, 2000);
         }
         return;
@@ -285,6 +293,10 @@ export class TS3Client extends EventEmitter {
     this.clientId = 0;
     this.httpQuery = null;
     this.detectedProtocol = "unknown";
+    if (this.udpErrorTimer) {
+      clearTimeout(this.udpErrorTimer);
+      this.udpErrorTimer = null;
+    }
     this.logger.info("Disconnected from TeamSpeak server");
   }
 }
diff --git a/src/ts-protocol/http-query.ts b/src/ts-protocol/http-query.ts
index d483265..a0af0cd 100644
--- a/src/ts-protocol/http-query.ts
+++ b/src/ts-protocol/http-query.ts
@@ -1,6 +1,5 @@
 import http from "node:http";
 import https from "node:https";
-import { EventEmitter } from "node:events";
 
 export interface HttpQueryOptions {
   host: string;
@@ -31,11 +30,10 @@ export interface HttpQueryResult {
  *   GET  /1/channellist?sid={sid}  → list channels
  *   POST /1/clientupdate           → update client properties
  */
-export class TS6HttpQuery extends EventEmitter {
+export class TS6HttpQuery {
   private options: Required<HttpQueryOptions>;
 
   constructor(options: HttpQueryOptions) {
-    super();
     this.options = {
       host: options.host,
       port: options.port,
@@ -68,6 +66,13 @@ export class TS6HttpQuery extends EventEmitter {
     }
 
     return new Promise((resolve, reject) => {
+      let settled = false;
+      const fail = (err: Error) => {
+        if (settled) return;
+        settled = true;
+        reject(err);
+      };
+
       const req = transport.request(
         {
           hostname: host,
@@ -82,8 +87,10 @@ export class TS6HttpQuery extends EventEmitter {
           let data = "";
           res.setEncoding("utf-8");
           res.on("data", (chunk: string) => (data += chunk));
-          res.on("error", reject);
+          res.on("error", fail);
           res.on("end", () => {
+            if (settled) return;
+            settled = true;
             let parsed: unknown;
             try {
               parsed = JSON.parse(data);
@@ -98,10 +105,10 @@ export class TS6HttpQuery extends EventEmitter {
         },
       );
 
-      req.on("error", reject);
+      req.on("error", fail);
       req.on("timeout", () => {
         req.destroy();
-        reject(new Error("TS6 HTTP Query timeout"));
+        fail(new Error("TS6 HTTP Query timeout"));
       });
 
       if (bodyStr) {
diff --git a/src/ts-protocol/protocol-detect.ts b/src/ts-protocol/protocol-detect.ts
index 7ef9475..b58b1d5 100644
--- a/src/ts-protocol/protocol-detect.ts
+++ b/src/ts-protocol/protocol-detect.ts
@@ -67,11 +67,13 @@ function probeTS3Query(host: string, port: number, timeoutMs: number): Promise<b
 
     const socket = net.createConnection({ host, port, timeout: timeoutMs });
     let banner = "";
+    const MAX_BANNER = 256; // TS3 banner is ~50 bytes; cap to avoid memory abuse
 
     socket.setTimeout(timeoutMs);
 
     socket.on("data", (data: Buffer) => {
       banner += data.toString("utf-8");
+      if (banner.length > MAX_BANNER) banner = banner.slice(0, MAX_BANNER);
       if (banner.includes("TS3")) {
         done(true);
       }