diff --git a/server.js b/server.js
index 491f8db..e8da91d 100644
--- a/server.js
+++ b/server.js
@@ -771,18 +771,33 @@ wss.on('connection', async (clientWs, req) => {
     }
   });
 
-  // Proxy: OpenClaw → Client (inject user preferences into connect response)
+  // Proxy: OpenClaw → Client (inject user preferences into connect response + filter by session)
   openclawWs.on('message', (data) => {
     const message = data.toString('utf8');
     console.log(`[proxy] OpenClaw → Client: ${message.substring(0, 100)}...`);
     console.log(`[proxy] Client WebSocket state: ${clientWs.readyState} (1=OPEN)`);
     
     let messageToSend = data;
+    let shouldForward = true;
     
-    // Try to inject user preferences into connect response
+    // Try to filter and modify messages
     try {
       const parsed = JSON.parse(message);
       
+      // Filter chat events by sessionKey - only forward if it's for this user's session
+      if (parsed.type === 'event' && parsed.event === 'chat') {
+        const payloadSessionKey = parsed.payload?.sessionKey;
+        const expectedSessionKey = `agent:main:${clientUserId}`;
+        
+        // Only forward if sessionKey matches user's session (or is main/unspecified for backwards compat)
+        if (payloadSessionKey && payloadSessionKey !== 'agent:main:main' && payloadSessionKey !== expectedSessionKey) {
+          console.log(`[proxy] Filtering out chat event: sessionKey=${payloadSessionKey}, expected=${expectedSessionKey}`);
+          shouldForward = false;
+        } else {
+          console.log(`[proxy] Forwarding chat event: sessionKey=${payloadSessionKey || 'main'} for user ${clientUserId}`);
+        }
+      }
+      
       // If this is a connect response, inject user preferences
       if (parsed.type === 'res' && parsed.ok && parsed.id && parsed.id.startsWith('connect-')) {
         console.log(`[prefs] Injecting user preferences into connect response for ${clientUserId}`);
@@ -841,13 +856,16 @@ This file is dynamically updated on each user connection by alfred-proxy.
       // Not JSON or couldn't parse, send as-is
     }
     
-    if (clientWs.readyState === WebSocket.OPEN) {
+    // Only forward if not filtered
+    if (shouldForward && clientWs.readyState === WebSocket.OPEN) {
       try {
         clientWs.send(messageToSend);
         console.log(`[proxy] Message sent to client successfully`);
       } catch (err) {
         console.error(`[proxy] Failed to send to client:`, err.message);
       }
+    } else if (!shouldForward) {
+      console.log(`[proxy] Message filtered, not forwarding to client`);
     } else {
       console.warn(`[proxy] Client WebSocket not open, cannot send (state=${clientWs.readyState})`);
     }