diff --git a/docs/duplex_interaction.svg b/docs/duplex_interaction.svg
new file mode 100644
index 0000000..9ccd0bb
--- /dev/null
+++ b/docs/duplex_interaction.svg
@@ -0,0 +1,96 @@
+<svg width="1200" height="620" viewBox="0 0 1200 620" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <style>
+      .box { fill:#11131a; stroke:#3a3f4b; stroke-width:1.2; rx:10; ry:10; }
+      .title { font: 600 14px 'Arial'; fill:#f2f3f7; }
+      .text { font: 12px 'Arial'; fill:#c8ccd8; }
+      .arrow { stroke:#7aa2ff; stroke-width:1.6; marker-end:url(#arrow); fill:none; }
+      .arrow2 { stroke:#2dd4bf; stroke-width:1.6; marker-end:url(#arrow); fill:none; }
+      .arrow3 { stroke:#ff6b6b; stroke-width:1.6; marker-end:url(#arrow); fill:none; }
+      .label { font: 11px 'Arial'; fill:#9aa3b2; }
+    </style>
+    <marker id="arrow" markerWidth="8" markerHeight="8" refX="7" refY="4" orient="auto">
+      <path d="M0,0 L8,4 L0,8 Z" fill="#7aa2ff"/>
+    </marker>
+  </defs>
+
+  <rect x="40" y="40" width="250" height="120" class="box"/>
+  <text x="60" y="70" class="title">Web Client</text>
+  <text x="60" y="95" class="text">WS JSON commands</text>
+  <text x="60" y="115" class="text">WS binary PCM audio</text>
+
+  <rect x="350" y="40" width="250" height="120" class="box"/>
+  <text x="370" y="70" class="title">FastAPI /ws</text>
+  <text x="370" y="95" class="text">Session + Transport</text>
+
+  <rect x="660" y="40" width="250" height="120" class="box"/>
+  <text x="680" y="70" class="title">DuplexPipeline</text>
+  <text x="680" y="95" class="text">process_audio / process_text</text>
+
+  <rect x="920" y="40" width="240" height="120" class="box"/>
+  <text x="940" y="70" class="title">ConversationManager</text>
+  <text x="940" y="95" class="text">turns + state</text>
+
+  <rect x="660" y="200" width="180" height="100" class="box"/>
+  <text x="680" y="230" class="title">VADProcessor</text>
+  <text x="680" y="255" class="text">speech/silence</text>
+
+  <rect x="860" y="200" width="180" height="100" class="box"/>
+  <text x="880" y="230" class="title">EOU Detector</text>
+  <text x="880" y="255" class="text">end-of-utterance</text>
+
+  <rect x="1060" y="200" width="120" height="100" class="box"/>
+  <text x="1075" y="230" class="title">ASR</text>
+  <text x="1075" y="255" class="text">transcripts</text>
+
+  <rect x="920" y="350" width="240" height="110" class="box"/>
+  <text x="940" y="380" class="title">LLM (stream)</text>
+  <text x="940" y="405" class="text">llmResponse events</text>
+
+  <rect x="660" y="350" width="220" height="110" class="box"/>
+  <text x="680" y="380" class="title">TTS (stream)</text>
+  <text x="680" y="405" class="text">PCM audio</text>
+
+  <rect x="40" y="350" width="250" height="110" class="box"/>
+  <text x="60" y="380" class="title">Web Client</text>
+  <text x="60" y="405" class="text">audio playback + UI</text>
+
+  <path d="M290 80 L350 80" class="arrow"/>
+  <text x="300" y="70" class="label">JSON / PCM</text>
+
+  <path d="M600 80 L660 80" class="arrow"/>
+  <text x="615" y="70" class="label">dispatch</text>
+
+  <path d="M910 80 L920 80" class="arrow"/>
+  <text x="880" y="70" class="label">turn mgmt</text>
+
+  <path d="M750 160 L750 200" class="arrow"/>
+  <text x="705" y="190" class="label">audio chunks</text>
+
+  <path d="M840 250 L860 250" class="arrow"/>
+  <text x="835" y="240" class="label">vad status</text>
+
+  <path d="M1040 250 L1060 250" class="arrow"/>
+  <text x="1010" y="240" class="label">audio buffer</text>
+
+  <path d="M950 300 L950 350" class="arrow2"/>
+  <text x="930" y="340" class="label">EOU -> LLM</text>
+
+  <path d="M880 405 L920 405" class="arrow2"/>
+  <text x="870" y="395" class="label">text stream</text>
+
+  <path d="M660 405 L290 405" class="arrow2"/>
+  <text x="430" y="395" class="label">PCM audio</text>
+
+  <path d="M660 450 L350 450" class="arrow"/>
+  <text x="420" y="440" class="label">events: trackStart/End</text>
+
+  <path d="M350 450 L290 450" class="arrow"/>
+  <text x="315" y="440" class="label">UI updates</text>
+
+  <path d="M750 200 L750 160" class="arrow3"/>
+  <text x="700" y="145" class="label">barge-in detection</text>
+
+  <path d="M760 170 L920 170" class="arrow3"/>
+  <text x="820" y="160" class="label">interrupt event + cancel</text>
+</svg>
diff --git a/examples/web_client.html b/examples/web_client.html
index 02ab70e..6838171 100644
--- a/examples/web_client.html
+++ b/examples/web_client.html
@@ -331,7 +331,6 @@
           <button class="secondary" id="refreshDevicesBtn">Refresh Devices</button>
           <button class="good" id="startMicBtn">Start Mic</button>
           <button class="secondary" id="stopMicBtn">Stop Mic</button>
-          <button class="bad" id="interruptBtn">Interrupt</button>
         </div>
 
         <h2>Chat</h2>
@@ -372,7 +371,6 @@
       const outputSelect = document.getElementById("outputSelect");
       const startMicBtn = document.getElementById("startMicBtn");
       const stopMicBtn = document.getElementById("stopMicBtn");
-      const interruptBtn = document.getElementById("interruptBtn");
       const refreshDevicesBtn = document.getElementById("refreshDevicesBtn");
       const sendChatBtn = document.getElementById("sendChatBtn");
       const clearLogBtn = document.getElementById("clearLogBtn");
@@ -504,6 +502,7 @@
           setStatus(true, "Session open");
           logLine("sys", "WebSocket connected");
           ensureAudioContext();
+          sendCommand({ command: "invite", option: { codec: "pcm", sampleRate: targetSampleRate } });
         };
 
         ws.onclose = () => {
@@ -653,7 +652,6 @@
       });
       startMicBtn.addEventListener("click", startMic);
       stopMicBtn.addEventListener("click", stopMic);
-      interruptBtn.addEventListener("click", () => sendCommand({ command: "interrupt" }));
       sendChatBtn.addEventListener("click", () => {
         const text = chatInput.value.trim();
         if (!text) return;