diff --git a/agent/agent.py b/agent/agent.py
index 24a3b9c..5f00453 100644
--- a/agent/agent.py
+++ b/agent/agent.py
@@ -758,6 +758,17 @@ async def handle_job(ctx: JobContext) -> None:
     )
 
     await ctx.connect()
+    # The participant can appear in the browser slightly before AgentSession is
+    # ready to accept lk.chat streams. Explicitly signal readiness so the first
+    # typed message is never raced against session startup.
+    try:
+        await ctx.room.local_participant.publish_data(
+            json.dumps({"type": "agent_ready"}),
+            reliable=True,
+            topic="conversation-control",
+        )
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("failed to publish agent readiness: %s", exc)
     logger.info("Agent connected to room %s", ctx.room.name)
 
 
diff --git a/web/app.js b/web/app.js
index 20ac5e5..d84f6e3 100644
--- a/web/app.js
+++ b/web/app.js
@@ -31,6 +31,7 @@ const MODE_KEY = "hope_conversation_mode";
 // ── State ───────────────────────────────────────────────────────────────────
 let room = null;
 let agentParticipant = null;
+let agentReady = false;
 let uiState = "idle";            // idle | connecting | listening | thinking | speaking
 let micLevel = 0;                // 0..1, smoothed
 let agentAudioLevel = 0;         // 0..1, smoothed
@@ -518,7 +519,9 @@ function registerTranscriptionStream(rm) {
 function handleDataPacket(payload, participant, topic) {
     try {
         const msg = JSON.parse(new TextDecoder().decode(payload));
-        if (msg.type === "transcript") {
+        if (msg.type === "agent_ready") {
+            agentReady = true;
+        } else if (msg.type === "transcript") {
             addMessage(msg.role || "agent", msg.text);
             if (conversationMode === "text" && (msg.role || "agent") === "agent") {
                 setState("listening");
@@ -721,6 +724,7 @@ function createRoom(token) {
         startBtn.disabled = false;
         stopBtn.disabled = true;
         agentParticipant = null;
+        agentReady = false;
     });
 
     return newRoom.connect(LIVEKIT_URL, token, {
@@ -733,6 +737,22 @@ function createRoom(token) {
     });
 }
 
+function waitForAgentReady(timeoutMs) {
+    return new Promise((resolve) => {
+        if (agentReady) return resolve(true);
+        const deadline = Date.now() + timeoutMs;
+        const timer = setInterval(() => {
+            if (agentReady) {
+                clearInterval(timer);
+                resolve(true);
+            } else if (Date.now() > deadline) {
+                clearInterval(timer);
+                resolve(false);
+            }
+        }, 100);
+    });
+}
+
 function waitForAgent(timeoutMs) {
     return new Promise((resolve) => {
         if (findAgent(room)) return resolve(true);
@@ -773,6 +793,7 @@ async function connectConversation() {
                 const stale = room;
                 room = null;
                 agentParticipant = null;
+                agentReady = false;
                 await stale.disconnect();
                 const freshToken = await fetchToken(ROOM_NAME);
                 room = await createRoom(freshToken);
@@ -780,6 +801,10 @@ async function connectConversation() {
                     throw new Error("Assistant did not join — reload the page and try again");
                 }
             }
+            statusEl.textContent = "Hope joined · Finishing setup…";
+            if (!(await waitForAgentReady(10000))) {
+                throw new Error("Assistant joined but was not ready — try again");
+            }
 
             sendModeMessage(conversationMode);
             if (conversationMode === "voice") {
@@ -870,6 +895,7 @@ stopBtn.addEventListener("click", () => {
         room.disconnect();
         room = null;
         agentParticipant = null;
+        agentReady = false;
     }
     teardownAudio();
     stopVisualLoop();