diff --git a/src/tests/queue/listener-tui-queue-parity.test.ts b/src/tests/queue/listener-tui-queue-parity.test.ts
new file mode 100644
index 0000000..51061c2
--- /dev/null
+++ b/src/tests/queue/listener-tui-queue-parity.test.ts
@@ -0,0 +1,161 @@
+import { describe, expect, test } from "bun:test";
+import type { MessageCreate } from "@letta-ai/letta-client/resources/agents/agents";
+import type { DequeuedBatch } from "../../queue/queueRuntime";
+import { QueueRuntime } from "../../queue/queueRuntime";
+
+type QueueItemArrival = { isUserMessage: boolean; queueItemId?: string };
+
+function makeMessageCreate(text: string): MessageCreate {
+  return { role: "user", content: text } as unknown as MessageCreate;
+}
+
+/**
+ * Mirrors listen-client arrival + turn-start/turn-end queue wiring.
+ */
+function simulateListenerScript(
+  script: Array<"arrive_a" | "arrive_b" | "turn_a" | "turn_b">,
+): DequeuedBatch[] {
+  const dequeuedBatches: DequeuedBatch[] = [];
+  const q = new QueueRuntime({
+    maxItems: Infinity,
+    callbacks: {
+      onDequeued: (batch) => dequeuedBatches.push(batch),
+    },
+  });
+  const pendingTurns = { value: 0 };
+  const skipIds = new Set<string>();
+  const arrivals: Record<"a" | "b", QueueItemArrival | undefined> = {
+    a: undefined,
+    b: undefined,
+  };
+
+  const messageByKey: Record<"a" | "b", MessageCreate> = {
+    a: makeMessageCreate("a"),
+    b: makeMessageCreate("b"),
+  };
+
+  for (const step of script) {
+    if (step.startsWith("arrive_")) {
+      const key = step.endsWith("_a") ? "a" : "b";
+      const payload = messageByKey[key];
+      const enqueued = q.enqueue({
+        kind: "message",
+        source: "user",
+        content: payload.content,
+      } as Parameters<typeof q.enqueue>[0]);
+      arrivals[key] = {
+        isUserMessage: true,
+        queueItemId: enqueued?.id,
+      };
+      if (pendingTurns.value > 0) {
+        q.tryDequeue("runtime_busy");
+      }
+      pendingTurns.value++;
+      continue;
+    }
+
+    const key = step.endsWith("_a") ? "a" : "b";
+    const arrival = arrivals[key];
+    if (arrival?.isUserMessage && arrival.queueItemId) {
+      if (skipIds.has(arrival.queueItemId)) {
+        skipIds.delete(arrival.queueItemId);
+      } else {
+        const batch = q.tryDequeue(null);
+        if (batch) {
+          for (const item of batch.items) {
+            if (item.id !== arrival.queueItemId) {
+              skipIds.add(item.id);
+            }
+          }
+        }
+      }
+    }
+    pendingTurns.value--;
+    if (pendingTurns.value === 0) {
+      q.resetBlockedState();
+    }
+  }
+
+  return dequeuedBatches;
+}
+
+/**
+ * Mirrors TUI queue wiring at the QueueRuntime boundary for the same scripts.
+ */
+function simulateTuiScript(
+  script: Array<"arrive_a" | "arrive_b" | "turn_a" | "turn_b">,
+): DequeuedBatch[] {
+  const dequeuedBatches: DequeuedBatch[] = [];
+  const q = new QueueRuntime({
+    maxItems: Infinity,
+    callbacks: {
+      onDequeued: (batch) => dequeuedBatches.push(batch),
+    },
+  });
+  const pendingTurns = { value: 0 };
+  const arrivals: Record<"a" | "b", boolean> = { a: false, b: false };
+
+  for (const step of script) {
+    if (step.startsWith("arrive_")) {
+      const key = step.endsWith("_a") ? "a" : "b";
+      q.enqueue({
+        kind: "message",
+        source: "user",
+        content: key,
+      } as Parameters<typeof q.enqueue>[0]);
+      arrivals[key] = true;
+      pendingTurns.value++;
+      continue;
+    }
+
+    // TUI drains all currently pending queue items when turn processing starts.
+    if (pendingTurns.value > 0) {
+      q.consumeItems(pendingTurns.value);
+      pendingTurns.value = 0;
+    }
+  }
+
+  return dequeuedBatches;
+}
+
+function simplifyProgression(batches: DequeuedBatch[]) {
+  return batches.map((batch) => ({
+    batchId: batch.batchId,
+    mergedCount: batch.mergedCount,
+  }));
+}
+
+describe("listener/TUI queue lifecycle parity", () => {
+  test("rapid two arrivals while busy produce identical batch progression", () => {
+    const script: Array<"arrive_a" | "arrive_b" | "turn_a" | "turn_b"> = [
+      "arrive_a",
+      "arrive_b",
+      "turn_a",
+      "turn_b",
+    ];
+
+    const listener = simplifyProgression(simulateListenerScript(script));
+    const tui = simplifyProgression(simulateTuiScript(script));
+
+    expect(listener).toEqual([{ batchId: "batch-1", mergedCount: 2 }]);
+    expect(tui).toEqual(listener);
+  });
+
+  test("sequential arrivals when idle produce identical progression", () => {
+    const script: Array<"arrive_a" | "arrive_b" | "turn_a" | "turn_b"> = [
+      "arrive_a",
+      "turn_a",
+      "arrive_b",
+      "turn_b",
+    ];
+
+    const listener = simplifyProgression(simulateListenerScript(script));
+    const tui = simplifyProgression(simulateTuiScript(script));
+
+    expect(listener).toEqual([
+      { batchId: "batch-1", mergedCount: 1 },
+      { batchId: "batch-2", mergedCount: 1 },
+    ]);
+    expect(tui).toEqual(listener);
+  });
+});