diff --git a/src/gateway/server-chat.ts b/src/gateway/server-chat.ts
index d54d0a99eeb..64675c8b5b7 100644
--- a/src/gateway/server-chat.ts
+++ b/src/gateway/server-chat.ts
@@ -352,6 +352,27 @@ export function createAgentEventHandler({
     const text = normalizedHeartbeatText.text.trim();
     const shouldSuppressSilent =
       normalizedHeartbeatText.suppress || isSilentReplyText(text, SILENT_REPLY_TOKEN);
+    // Flush any throttled delta so streaming clients receive the complete text
+    // before the final event.  The 150 ms throttle in emitChatDelta may have
+    // suppressed the most recent chunk, leaving the client with stale text.
+    if (text && !shouldSuppressSilent) {
+      const lastSent = chatRunState.deltaSentAt.get(clientRunId) ?? 0;
+      if (lastSent > 0) {
+        const flushPayload = {
+          runId: clientRunId,
+          sessionKey,
+          seq,
+          state: "delta" as const,
+          message: {
+            role: "assistant",
+            content: [{ type: "text", text }],
+            timestamp: Date.now(),
+          },
+        };
+        broadcast("chat", flushPayload, { dropIfSlow: true });
+        nodeSendToSession(sessionKey, "chat", flushPayload);
+      }
+    }
     chatRunState.buffers.delete(clientRunId);
     chatRunState.deltaSentAt.delete(clientRunId);
     if (jobState === "done") {