diff --git a/frontend/app.js b/frontend/app.js
new file mode 100644
index 0000000..1a36543
--- /dev/null
+++ b/frontend/app.js
@@ -0,0 +1,111 @@
+(function () {
+  'use strict';
+
+  // ── DOM refs ──────────────────────────────────────────────────────────────
+  const body        = document.body;
+  const wsDot       = document.getElementById('ws-dot');
+  const stateLabel  = document.getElementById('state-label');
+  const progressFill  = document.getElementById('progress-fill');
+  const progressLabel = document.getElementById('progress-label');
+  const svModel     = document.getElementById('sv-model');
+  const svState     = document.getElementById('sv-state');
+  const svPrompt    = document.getElementById('sv-prompt');
+  const svSpeed     = document.getElementById('sv-speed');
+  const svTokens    = document.getElementById('sv-tokens');
+  const svLoadStage = document.getElementById('sv-load-stage');
+  const svReqs      = document.getElementById('sv-reqs');
+
+  // ── State class management ────────────────────────────────────────────────
+  const ALL_STATES = [
+    'offline','starting','loading','warming_up','idle',
+    'sleeping','waiting','processing_prompt','generating','unloading'
+  ];
+
+  function applyState(stateName) {
+    ALL_STATES.forEach(s => body.classList.remove('state-' + s));
+    body.classList.add('state-' + (ALL_STATES.includes(stateName) ? stateName : 'offline'));
+  }
+
+  // ── DOM update ────────────────────────────────────────────────────────────
+  function fmt(val, unit) {
+    return val != null ? val.toFixed(1) + ' ' + unit : '—';
+  }
+
+  function truncate(str, max) {
+    return str.length > max ? '…' + str.slice(-(max - 1)) : str;
+  }
+
+  function update(msg) {
+    const { state, model, loading, metrics, request_count } = msg;
+
+    applyState(state);
+
+    stateLabel.textContent = state.replace('_', ' ').toUpperCase();
+    svState.textContent    = state.replace('_', ' ');
+    svModel.textContent    = model ? truncate(model, 22) : '—';
+    svReqs.textContent     = request_count ?? 0;
+
+    // Loading progress
+    if (loading) {
+      const pct = Math.round((loading.progress ?? 0) * 100);
+      progressFill.style.width  = pct + '%';
+      progressLabel.textContent = loading.current + '  ' + pct + '%';
+      svLoadStage.textContent   = loading.current;
+    } else {
+      progressFill.style.width  = '0%';
+      progressLabel.textContent = '';
+      svLoadStage.textContent   = '—';
+    }
+
+    // Metrics
+    if (metrics) {
+      svPrompt.textContent  = fmt(metrics.prompt_speed, 't/s');
+      svSpeed.textContent   = fmt(metrics.gen_speed, 't/s');
+      svTokens.textContent  = metrics.n_decoded != null ? metrics.n_decoded + ' tok' : '—';
+    } else {
+      svPrompt.textContent = svSpeed.textContent = svTokens.textContent = '—';
+    }
+
+    // Pulse dot on message
+    wsDot.classList.remove('pulse');
+    void wsDot.offsetWidth; // force reflow to restart animation
+    wsDot.classList.add('pulse');
+  }
+
+  // ── WebSocket with auto-reconnect ─────────────────────────────────────────
+  let ws = null;
+  let retryDelay = 1000;
+  const MAX_DELAY = 30000;
+
+  function connect() {
+    const url = 'ws://' + location.host + '/ws';
+    ws = new WebSocket(url);
+
+    ws.addEventListener('open', () => {
+      wsDot.className = 'connected';
+      retryDelay = 1000;
+    });
+
+    ws.addEventListener('message', (event) => {
+      try {
+        update(JSON.parse(event.data));
+      } catch (e) {
+        console.error('llamagochi: bad message', e);
+      }
+    });
+
+    ws.addEventListener('close', () => {
+      wsDot.className = '';
+      applyState('offline');
+      stateLabel.textContent = 'DISCONNECTED';
+      setTimeout(connect, retryDelay);
+      retryDelay = Math.min(retryDelay * 2, MAX_DELAY);
+    });
+
+    ws.addEventListener('error', () => {
+      ws.close();
+    });
+  }
+
+  connect();
+})();