diff --git a/test/event-target-redis.test.ts b/test/event-target-redis.test.ts
new file mode 100644
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--- /dev/null
+++ b/test/event-target-redis.test.ts
@@ -0,0 +1,435 @@
+import { describe, it, expect, vi } from "vitest";
+import { createRedisEventTarget } from "../src/event-target-redis.js";
+import type { EventEnvelope, TypedEvent } from "../src/types.js";
+
+type TestEvent = TypedEvent<string, EventEnvelope>;
+
+function createMockRedis() {
+  const publications: { channel: string; message: string }[] = [];
+  const subscriptions: { channel: string }[] = [];
+  const unsubscriptions: { channel: string }[] = [];
+  let messageListener: ((channel: string, message: string) => void) | null = null;
+
+  return {
+    publish: vi.fn((channel: string, message: string) => {
+      publications.push({ channel, message });
+    }),
+    subscribe: vi.fn((channel: string) => {
+      subscriptions.push({ channel });
+    }),
+    unsubscribe: vi.fn((channel: string) => {
+      unsubscriptions.push({ channel });
+    }),
+    on: vi.fn((event: string, callback: (channel: string, message: string) => void) => {
+      if (event === "message") {
+        messageListener = callback;
+      }
+      return {} as any;
+    }),
+    publications,
+    subscriptions,
+    unsubscriptions,
+    simulateMessage(channel: string, message: string) {
+      if (messageListener) {
+        messageListener(channel, message);
+      }
+    },
+  };
+}
+
+describe("createRedisEventTarget", () => {
+  describe("dispatchEvent (publish path)", () => {
+    it("publishes to Redis with correct channel name matching event type", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const event = new CustomEvent("call.responded:uuid-123", {
+        detail: { type: "call.responded", id: "uuid-123", payload: { status: "ok" } },
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      expect(publishClient.publish).toHaveBeenCalledTimes(1);
+      expect(publishClient.publish).toHaveBeenCalledWith(
+        "call.responded:uuid-123",
+        JSON.stringify({ type: "call.responded", id: "uuid-123", payload: { status: "ok" } }),
+      );
+    });
+
+    it("serializes the envelope detail using the default JSON serializer", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const envelope: EventEnvelope<"user.joined", { name: string }> = {
+        type: "user.joined",
+        id: "user-42",
+        payload: { name: "Alice" },
+      };
+
+      const event = new CustomEvent("user.joined:user-42", {
+        detail: envelope,
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      expect(publishClient.publish).toHaveBeenCalledTimes(1);
+      const publishedMessage = publishClient.publications[0].message;
+      expect(JSON.parse(publishedMessage)).toEqual(envelope);
+    });
+
+    it("returns true from dispatchEvent", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const event = new CustomEvent("test.event:id1", {
+        detail: { type: "test.event", id: "id1", payload: null },
+      }) as TestEvent;
+
+      const result = eventTarget.dispatchEvent(event);
+      expect(result).toBe(true);
+    });
+  });
+
+  describe("addEventListener (subscribe path)", () => {
+    it("subscribes to Redis on the topic when first listener is added", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("message.sent:msg1", listener);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledTimes(1);
+      expect(subscribeClient.subscribe).toHaveBeenCalledWith("message.sent:msg1");
+    });
+
+    it("dispatches deserialized messages to local listeners", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("message.sent:msg1", listener);
+
+      const envelope: EventEnvelope = {
+        type: "message.sent",
+        id: "msg1",
+        payload: "hello world",
+      };
+      subscribeClient.simulateMessage("message.sent:msg1", JSON.stringify(envelope));
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const receivedEvent = listener.mock.calls[0][0] as TestEvent;
+      expect(receivedEvent.type).toBe("message.sent:msg1");
+      expect(receivedEvent.detail).toEqual(envelope);
+    });
+
+    it("ignores messages on channels with no registered listeners", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("topic:a", listener);
+
+      subscribeClient.simulateMessage("topic:b", JSON.stringify({ type: "topic", id: "b", payload: null }));
+
+      expect(listener).not.toHaveBeenCalled();
+    });
+  });
+
+  describe("removeEventListener (unsubscribe path)", () => {
+    it("unsubscribes from Redis when the last listener for a topic is removed", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("topic:a", listener);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledTimes(1);
+
+      eventTarget.removeEventListener("topic:a", listener);
+
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledTimes(1);
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledWith("topic:a");
+    });
+
+    it("does not unsubscribe from Redis while other listeners remain on the same topic", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener1 = vi.fn();
+      const listener2 = vi.fn();
+      eventTarget.addEventListener("event:type1", listener1);
+      eventTarget.addEventListener("event:type1", listener2);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledTimes(1);
+
+      eventTarget.removeEventListener("event:type1", listener1);
+
+      expect(subscribeClient.unsubscribe).not.toHaveBeenCalled();
+
+      eventTarget.removeEventListener("event:type1", listener2);
+
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledTimes(1);
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledWith("event:type1");
+    });
+  });
+
+  describe("topic scoping", () => {
+    it("uses type:id strings as Redis channel names", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("call.responded:uuid-456", listener);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledWith("call.responded:uuid-456");
+
+      const event = new CustomEvent("call.responded:uuid-456", {
+        detail: { type: "call.responded", id: "uuid-456", payload: { ok: true } },
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      expect(publishClient.publications[0].channel).toBe("call.responded:uuid-456");
+    });
+  });
+
+  describe("EventEnvelope serialization round-trip", () => {
+    it("round-trips full { type, id, payload } envelope through JSON", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("user.joined:user-99", listener);
+
+      const originalEnvelope: EventEnvelope<"user.joined", { name: string; role: string }> = {
+        type: "user.joined",
+        id: "user-99",
+        payload: { name: "Bob", role: "admin" },
+      };
+
+      const event = new CustomEvent("user.joined:user-99", {
+        detail: originalEnvelope,
+      }) as TestEvent;
+
+      eventTarget.dispatchEvent(event);
+
+      const publishedMessage = publishClient.publications[0].message;
+      subscribeClient.simulateMessage("user.joined:user-99", publishedMessage);
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const receivedDetail = (listener.mock.calls[0][0] as TestEvent).detail as EventEnvelope;
+      expect(receivedDetail).toEqual(originalEnvelope);
+      expect(receivedDetail.type).toBe("user.joined");
+      expect(receivedDetail.id).toBe("user-99");
+      expect(receivedDetail.payload).toEqual({ name: "Bob", role: "admin" });
+    });
+
+    it("round-trips envelope with null payload", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("ping:1", listener);
+
+      const envelope: EventEnvelope = { type: "ping", id: "1", payload: null };
+      subscribeClient.simulateMessage("ping:1", JSON.stringify(envelope));
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const receivedDetail = (listener.mock.calls[0][0] as TestEvent).detail as EventEnvelope;
+      expect(receivedDetail).toEqual(envelope);
+    });
+  });
+
+  describe("multiple listeners on the same topic", () => {
+    it("subscribes to Redis only once when multiple listeners are added to the same topic", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener1 = vi.fn();
+      const listener2 = vi.fn();
+      const listener3 = vi.fn();
+
+      eventTarget.addEventListener("topic:x", listener1);
+      eventTarget.addEventListener("topic:x", listener2);
+      eventTarget.addEventListener("topic:x", listener3);
+
+      expect(subscribeClient.subscribe).toHaveBeenCalledTimes(1);
+      expect(subscribeClient.subscribe).toHaveBeenCalledWith("topic:x");
+    });
+
+    it("delivers messages to all listeners on the same topic", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const listener1 = vi.fn();
+      const listener2 = vi.fn();
+      eventTarget.addEventListener("topic:x", listener1);
+      eventTarget.addEventListener("topic:x", listener2);
+
+      const envelope: EventEnvelope = { type: "topic", id: "x", payload: "data" };
+      subscribeClient.simulateMessage("topic:x", JSON.stringify(envelope));
+
+      expect(listener1).toHaveBeenCalledTimes(1);
+      expect(listener2).toHaveBeenCalledTimes(1);
+      expect((listener1.mock.calls[0][0] as TestEvent).detail).toEqual(envelope);
+      expect((listener2.mock.calls[0][0] as TestEvent).detail).toEqual(envelope);
+    });
+  });
+
+  describe("custom serializer", () => {
+    it("uses custom serializer for stringify and parse", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const customSerializer = {
+        stringify: vi.fn((value: unknown) => JSON.stringify(value)),
+        parse: vi.fn((text: string) => JSON.parse(text)),
+      };
+
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        serializer: customSerializer,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("custom:event1", listener);
+
+      const envelope: EventEnvelope = { type: "custom", id: "event1", payload: { key: "value" } };
+      const event = new CustomEvent("custom:event1", { detail: envelope }) as TestEvent;
+      eventTarget.dispatchEvent(event);
+
+      expect(customSerializer.stringify).toHaveBeenCalledTimes(1);
+      expect(customSerializer.stringify).toHaveBeenCalledWith(envelope);
+
+      const publishedMessage = publishClient.publications[0].message;
+      subscribeClient.simulateMessage("custom:event1", publishedMessage);
+
+      expect(customSerializer.parse).toHaveBeenCalledTimes(1);
+      expect(customSerializer.parse).toHaveBeenCalledWith(publishedMessage);
+      expect(listener).toHaveBeenCalledTimes(1);
+    });
+
+    it("allows non-JSON serializers to round-trip envelopes", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+
+      const prefixSerializer = {
+        stringify: (value: unknown) => `PREFIX:${JSON.stringify(value)}`,
+        parse: (text: string) => JSON.parse(text.slice(7)),
+      };
+
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+        serializer: prefixSerializer,
+      });
+
+      const listener = vi.fn();
+      eventTarget.addEventListener("test:str", listener);
+
+      const envelope: EventEnvelope = { type: "test", id: "str", payload: 42 };
+      const event = new CustomEvent("test:str", { detail: envelope }) as TestEvent;
+      eventTarget.dispatchEvent(event);
+
+      const publishedMessage = publishClient.publications[0].message;
+      expect(publishedMessage).toBe(`PREFIX:${JSON.stringify(envelope)}`);
+
+      subscribeClient.simulateMessage("test:str", publishedMessage);
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const receivedDetail = (listener.mock.calls[0][0] as TestEvent).detail as EventEnvelope;
+      expect(receivedDetail).toEqual(envelope);
+    });
+  });
+
+  describe("EventListenerObject support", () => {
+    it("addEventListener accepts EventListenerObject with handleEvent", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const handleEvent = vi.fn();
+      const listenerObject = { handleEvent };
+
+      eventTarget.addEventListener("obj:test", listenerObject);
+
+      const envelope: EventEnvelope = { type: "obj", id: "test", payload: true };
+      subscribeClient.simulateMessage("obj:test", JSON.stringify(envelope));
+
+      expect(handleEvent).toHaveBeenCalledTimes(1);
+    });
+
+    it("removeEventListener accepts EventListenerObject with handleEvent", () => {
+      const publishClient = createMockRedis();
+      const subscribeClient = createMockRedis();
+      const eventTarget = createRedisEventTarget<TestEvent>({
+        publishClient: publishClient as any,
+        subscribeClient: subscribeClient as any,
+      });
+
+      const handleEvent = vi.fn();
+      const listenerObject = { handleEvent };
+
+      eventTarget.addEventListener("obj:test2", listenerObject);
+      expect(subscribeClient.subscribe).toHaveBeenCalledWith("obj:test2");
+
+      eventTarget.removeEventListener("obj:test2", listenerObject);
+      expect(subscribeClient.unsubscribe).toHaveBeenCalledWith("obj:test2");
+    });
+  });
+});
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