diff --git a/neode-ui/docker/nginx-demo.conf b/neode-ui/docker/nginx-demo.conf
index 4381040d..2c918631 100644
--- a/neode-ui/docker/nginx-demo.conf
+++ b/neode-ui/docker/nginx-demo.conf
@@ -78,6 +78,14 @@ http {
             }
         }
 
+        # Proxy AIUI API requests (web-search, claude) to backend
+        location /aiui/api/web-search {
+            proxy_pass http://neode-backend:5959;
+            proxy_http_version 1.1;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+        }
+
         # Proxy Claude API requests to backend (which handles API key + streaming)
         location /aiui/api/claude/ {
             proxy_pass http://neode-backend:5959;
diff --git a/neode-ui/mock-backend.js b/neode-ui/mock-backend.js
index 4340e12d..8e560485 100755
--- a/neode-ui/mock-backend.js
+++ b/neode-ui/mock-backend.js
@@ -1017,6 +1017,12 @@ app.get('/app/filebrowser/api/raw/*', (req, res) => {
 })
 
 // =============================================================================
+// AIUI Web Search stub (demo mode — no real search backend)
+// =============================================================================
+app.get('/aiui/api/web-search', (req, res) => {
+  res.json({ results: [] })
+})
+
 // Claude API Proxy (reads ANTHROPIC_API_KEY from environment)
 // =============================================================================
 import https from 'https'
@@ -1031,7 +1037,14 @@ app.post('/aiui/api/claude/*', (req, res) => {
   }
 
   const apiPath = '/' + req.params[0]
-  const bodyStr = JSON.stringify(req.body)
+
+  // Ensure max_tokens is set — Claude API requires it but AIUI may omit it
+  const body = req.body
+  if (body && !body.max_tokens) {
+    body.max_tokens = 4096
+  }
+
+  const bodyStr = JSON.stringify(body)
 
   const options = {
     hostname: 'api.anthropic.com',
@@ -1098,7 +1111,7 @@ wss.on('connection', (ws, req) => {
   const heartbeatInterval = setInterval(() => {
     if (ws.readyState === 1) {
       try {
-        ws.send(JSON.stringify({ rev: Date.now(), patch: [] }))
+        ws.send(JSON.stringify({ type: 'heartbeat', rev: Date.now() }))
       } catch { /* ignore */ }
     }
   }, 45000) // Every 45s (client expects data within 60s)