diff --git a/source/event.ts b/source/event.ts
index 88fcd98b..4f862831 100644
--- a/source/event.ts
+++ b/source/event.ts
@@ -24,7 +24,7 @@ export class Event {
   constructor(
     topic: string,
     data: object,
-    options: { [key: string]: object } = {}
+    options: { [key: string]: unknown } = {}
   ) {
     this._data = {
       topic,
@@ -41,7 +41,15 @@ export class Event {
     return this._data;
   }
 
-  /** Add source to event data. */
+  /** Add source to event data, keeping any already avalable source information  */
+  prepareSource(source: object): void {
+    this._data.source = {
+      ...source,
+      ...this._data.source,
+    };
+  }
+
+  /** Add source to event data, replacing any previous data. */
   addSource(source: any): void {
     this._data.source = source;
   }
diff --git a/source/event_hub.ts b/source/event_hub.ts
index 9b06bbb9..4b2c3174 100644
--- a/source/event_hub.ts
+++ b/source/event_hub.ts
@@ -271,7 +271,7 @@ export class EventHub {
       );
     }
 
-    event.addSource({
+    event.prepareSource({
       id: this._id,
       applicationId: this._applicationId,
       user: {
@@ -613,13 +613,11 @@ export class EventHub {
     data: Data,
     source: Data | null = null
   ): Promise<string> {
-    const replyEvent = new Event("ftrack.meta.reply", {
-      ...data,
+    const replyEvent = new Event("ftrack.meta.reply", data, {
       target: `id=${sourceEventPayload.source.id}`,
       inReplyToEvent: sourceEventPayload.id,
-      source: source ?? data.source,
+      source: source,
     });
-
     return this.publish(replyEvent);
   }
 }
diff --git a/test/event.test.ts b/test/event.test.ts
new file mode 100644
index 00000000..2f3435a0
--- /dev/null
+++ b/test/event.test.ts
@@ -0,0 +1,98 @@
+// :copyright: Copyright (c) 2023 ftrack
+
+import { Event } from "../source/event";
+import { describe, expect, it } from "vitest";
+
+describe("Event class", () => {
+  it("should initialize with correct topic and data", () => {
+    const event = new Event("testTopic", { key: "value" });
+    const data = event.getData();
+    expect(data.topic).toBe("testTopic");
+    expect(data.data).toEqual({ key: "value" });
+  });
+
+  it("should have default properties", () => {
+    const event = new Event("testTopic", { key: "value" });
+    const data = event.getData();
+    expect(data.target).toBe("");
+    expect(data.inReplyToEvent).toBeNull();
+  });
+
+  it("should set properties from options", () => {
+    const event = new Event(
+      "testTopic",
+      { key: "value" },
+      { target: "sampleTarget", customOption: "customValue" }
+    );
+    const data = event.getData();
+    expect(data.target).toBe("sampleTarget");
+    expect(data.customOption).toBe("customValue");
+  });
+
+  it("should generate unique UUID", () => {
+    const event1 = new Event("testTopic", { key: "value" });
+    const event2 = new Event("testTopic", { key: "value" });
+    const data1 = event1.getData();
+    const data2 = event2.getData();
+    const uuidRegexExp =
+      /^[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{12}$/gi;
+    expect(data1.id).not.toBe(data2.id);
+    expect(uuidRegexExp.test(data1.id)).toBe(true);
+  });
+
+  it("should add source to event data", () => {
+    const event = new Event("testTopic", { key: "value" });
+    const source = {
+      id: "testId",
+      applicationId: "testApplicationId",
+      user: {
+        username: "testUser",
+      },
+    };
+    event.addSource(source);
+    const data = event.getData();
+    expect(data.source).toBe(source);
+  });
+  describe("prepareSource Method", () => {
+    it("should prepare and add source to event data", () => {
+      const event = new Event("testTopic", { key: "value" });
+      event.prepareSource({ newKey: "newValue" });
+      const data = event.getData();
+      expect(data.source).toEqual({ newKey: "newValue" });
+    });
+
+    it("should not override existing source when preparing a new source", () => {
+      const event = new Event(
+        "testTopic",
+        { key: "value" },
+        { source: { oldKey: "oldValue" } }
+      );
+      event.prepareSource({ oldKey: "newValue", newKey: "newValue" });
+      const data = event.getData();
+      expect(data.source).toEqual({
+        oldKey: "oldValue",
+        newKey: "newValue",
+      });
+    });
+    it("should handle source undefined", () => {
+      const event = new Event(
+        "testTopic",
+        { key: "value" },
+        { source: undefined }
+      );
+      event.prepareSource({ newKey: "newValue" });
+      const data = event.getData();
+      expect(data.source).toEqual({
+        newKey: "newValue",
+      });
+    });
+    it("Prepare should handle source null", () => {
+      const event = new Event("testTopic", { key: "value" }, { source: null });
+      event.prepareSource({ newKey: "newValue" });
+      const data = event.getData();
+      expect(data.source).toEqual({
+        newKey: "newValue",
+      });
+    });
+  });
+});
diff --git a/test/event_hub.test.ts b/test/event_hub.test.ts
index 94d94cf6..d27585a9 100644
--- a/test/event_hub.test.ts
+++ b/test/event_hub.test.ts
@@ -1,4 +1,5 @@
 import { EventHub } from "../source/event_hub";
+import { Event } from "../source/event";
 import { vi, describe, expect, beforeEach, afterEach, test } from "vitest";
 
 describe("EventHub", () => {
@@ -208,4 +209,33 @@ describe("EventHub", () => {
     );
     publishReplySpy.mockRestore();
   });
+  test("publishReply published Event with correct shape", async () => {
+    eventHub.publish = vi.fn();
+
+    const sourceEventPayload = {
+      source: { id: "testId" },
+      id: "anotherTestId",
+    };
+
+    const data = {
+      someData: "value",
+    };
+
+    await eventHub.publishReply(sourceEventPayload, data);
+
+    const publishedEvent = eventHub.publish.mock.calls[0][0];
+    expect(publishedEvent).toBeInstanceOf(Event);
+    const EventData = publishedEvent.getData();
+    // Ignoring the id field for comparison
+    delete EventData.id;
+
+    const expectedEvent = {
+      topic: "ftrack.meta.reply",
+      data: { someData: "value" },
+      source: null,
+      target: "id=testId",
+      inReplyToEvent: "anotherTestId",
+    };
+    expect(EventData).toEqual(expectedEvent);
+  });
 });