diff --git a/main.go b/main.go
index b91b0fe..aa46825 100644
--- a/main.go
+++ b/main.go
@@ -2287,7 +2287,38 @@ func apiAlarms(w http.ResponseWriter, r *http.Request) {
 
 func serveUI(w http.ResponseWriter, r *http.Request) {
 	if r.URL.Path == "/" {
-		// Parse and execute template with config data
+		// Check license before serving the UI
+		if licenseMgr != nil {
+			status := licenseMgr.Status()
+			if status.Locked {
+				// Serve fallback activation page when locked
+				w.Header().Set("Content-Type", "text/html; charset=utf-8")
+				fmt.Fprintf(w, `<!doctype html>
+<html><head><meta charset="utf-8"><title>Force Monitor — License Required</title>
+<style>body{font-family:Segoe UI,Arial,sans-serif;background:#0f172a;color:#e2e8f0;margin:0;padding:32px} .card{max-width:760px;margin:0 auto;background:#111827;padding:24px;border-radius:16px} code,pre{background:#020617;padding:10px;border-radius:12px;display:block;white-space:pre-wrap} button{padding:10px 16px;border-radius:10px;border:0;background:#2563eb;color:#fff;cursor:pointer} textarea{width:100%%;min-height:180px;border-radius:12px;padding:12px;background:#020617;color:#e2e8f0;border:1px solid #334155}</style></head>
+<body><div class="card"><h1>Force Monitor</h1><p><strong>Machine fingerprint:</strong> %s</p>
+<p><strong>License mode:</strong> %s</p>
+<p><strong>Message:</strong> %s</p>
+<p><a href="/api/license/status" style="color:#93c5fd">GET /api/license/status</a></p>
+<p><a href="/api/license/request" style="color:#93c5fd">GET /api/license/request</a></p>
+<h3>Paste signed license JSON</h3>
+<textarea id="licenseText" placeholder='{"app":"force_monitor",...}'></textarea>
+<div style="margin-top:12px"><button onclick="activate()">Activate license</button></div>
+<pre id="out"></pre>
+<script>
+async function activate(){
+  const t = document.getElementById('licenseText').value;
+  const res = await fetch('/api/license/activate', {method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify({license_text:t})});
+  const j = await res.json().catch(() => ({}));
+  document.getElementById('out').textContent = JSON.stringify(j, null, 2);
+  if(j.status === 'activated') setTimeout(() => location.reload(), 800);
+}
+</script></div></body></html>`, status.FingerprintShort, status.Mode, status.Message)
+				return
+			}
+		}
+
+		// License OK — serve the full dashboard template
 		tmpl, err := template.ParseFiles(filepath.Join("static", "index.html"))
 		if err != nil {
 			log.Printf("template parse error: %v", err)
