diff --git a/extension/src/ws-client.ts b/extension/src/ws-client.ts
index 28d9fda..afafda1 100644
--- a/extension/src/ws-client.ts
+++ b/extension/src/ws-client.ts
@@ -212,36 +212,68 @@ export class WSBridgeClient {
             this.logFn(`[WS] Connecting to ${this.hubUrl}...`);
             const ws = new WebSocket(this.hubUrl);
 
-            ws.on('open', () => {
-                this.logFn('[WS] Connection opened, authenticating...');
-                this.ws = ws;
-                this.connected = true;
-                this._authenticate();
-            });
+            // Detect API style: Node.js 'ws' module has .on(), browser WebSocket doesn't
+            const isNodeWs = typeof ws.on === 'function';
 
-            ws.on('message', (raw: Buffer | string) => {
-                try {
-                    const data = JSON.parse(typeof raw === 'string' ? raw : raw.toString('utf-8'));
-                    this._handleMessage(data);
-                } catch (e: any) {
-                    this.logFn(`[WS] Parse error: ${e.message}`);
-                }
-            });
+            if (isNodeWs) {
+                // ─── Node.js ws module (EventEmitter API) ───
+                ws.on('open', () => {
+                    this.logFn('[WS] Connection opened, authenticating...');
+                    this.ws = ws;
+                    this.connected = true;
+                    this._authenticate();
+                });
 
-            ws.on('close', (code: number, reason: Buffer) => {
-                const reasonStr = reason ? reason.toString('utf-8') : '';
-                this.logFn(`[WS] Connection closed: code=${code} reason=${reasonStr}`);
-                this._onDisconnect();
-            });
+                ws.on('message', (raw: Buffer | string) => {
+                    try {
+                        const data = JSON.parse(typeof raw === 'string' ? raw : raw.toString('utf-8'));
+                        this._handleMessage(data);
+                    } catch (e: any) {
+                        this.logFn(`[WS] Parse error: ${e.message}`);
+                    }
+                });
 
-            ws.on('error', (err: Error) => {
-                this.logFn(`[WS] Error: ${err.message}`);
-                // close event will follow
-            });
+                ws.on('close', (code: number, reason: Buffer) => {
+                    const reasonStr = reason ? reason.toString('utf-8') : '';
+                    this.logFn(`[WS] Connection closed: code=${code} reason=${reasonStr}`);
+                    this._onDisconnect();
+                });
 
-            ws.on('pong', () => {
-                // Server responded to our ping — connection is alive
-            });
+                ws.on('error', (err: Error) => {
+                    this.logFn(`[WS] Error: ${err.message}`);
+                });
+
+                ws.on('pong', () => {
+                    // Server responded to our ping — connection is alive
+                });
+            } else {
+                // ─── Browser-style WebSocket API (.onopen / .onmessage) ───
+                ws.onopen = () => {
+                    this.logFn('[WS] Connection opened (browser API), authenticating...');
+                    this.ws = ws;
+                    this.connected = true;
+                    this._authenticate();
+                };
+
+                ws.onmessage = (event: any) => {
+                    try {
+                        const raw = typeof event.data === 'string' ? event.data : event.data.toString();
+                        const data = JSON.parse(raw);
+                        this._handleMessage(data);
+                    } catch (e: any) {
+                        this.logFn(`[WS] Parse error: ${e.message}`);
+                    }
+                };
+
+                ws.onclose = (event: any) => {
+                    this.logFn(`[WS] Connection closed: code=${event.code} reason=${event.reason || ''}`);
+                    this._onDisconnect();
+                };
+
+                ws.onerror = (event: any) => {
+                    this.logFn(`[WS] Error: ${event.message || 'connection error'}`);
+                };
+            }
 
         } catch (e: any) {
             this.logFn(`[WS] Connect failed: ${e.message}`);
@@ -251,16 +283,16 @@ export class WSBridgeClient {
 
     private async _getWebSocketClass(): Promise<any> {
         try {
-            // Try Node.js built-in WebSocket (v21+)
-            if (typeof globalThis.WebSocket !== 'undefined') {
-                return globalThis.WebSocket;
-            }
-            // Try require('ws') — should be available in VS Code's Node.js
+            // Prefer require('ws') — Node.js EventEmitter API with .on()
+            // VS Code runs in Node.js, so this should be available
             const ws = require('ws');
             return ws;
         } catch {
-            // ws module not available  
+            // ws module not available — try built-in WebSocket
             try {
+                if (typeof globalThis.WebSocket !== 'undefined') {
+                    return globalThis.WebSocket;
+                }
                 // Fallback: try the built-in undici WebSocket
                 const { WebSocket } = require('undici');
                 return WebSocket;
@@ -424,7 +456,13 @@ export class WSBridgeClient {
         this.heartbeatTimer = setInterval(() => {
             if (this.ws && this.connected) {
                 try {
-                    this.ws.ping();
+                    // Node.js ws has .ping(), browser WebSocket doesn't
+                    if (typeof this.ws.ping === 'function') {
+                        this.ws.ping();
+                    } else {
+                        // Fallback: send heartbeat as JSON message
+                        this.ws.send(JSON.stringify({ type: 'heartbeat' }));
+                    }
                 } catch {
                     // ping failure will trigger close event
                 }