diff --git a/src/components/Sidebar/index.jsx b/src/components/Sidebar/index.jsx
index 2d47f297..203b7d23 100644
--- a/src/components/Sidebar/index.jsx
+++ b/src/components/Sidebar/index.jsx
@@ -2,6 +2,7 @@ import React, { useRef, useEffect } from 'react';
 import { useDispatch, useSelector } from 'react-redux';
 import PropTypes from 'prop-types';
 import { sendTrackEvent } from '@edx/frontend-platform/analytics';
+import { getAuthenticatedUser } from '@edx/frontend-platform/auth';
 import {
   Button,
   Icon,
@@ -9,6 +10,7 @@ import {
 } from '@openedx/paragon';
 import { Close } from '@openedx/paragon/icons';
 
+import { usePromptExperiment } from '../../utils/optimizelyExperiment';
 import APIError from '../APIError';
 import ChatBox from '../ChatBox';
 import Disclosure from '../Disclosure';
@@ -31,6 +33,8 @@ const Sidebar = ({
   } = useSelector(state => state.learningAssistant);
   const chatboxContainerRef = useRef(null);
   const dispatch = useDispatch();
+  const { userId } = getAuthenticatedUser();
+  const [ variationKey, experimentName ] = usePromptExperiment(userId);
 
   // this use effect is intended to scroll to the bottom of the chat window, in the case
   // that a message is larger than the chat window height.
@@ -80,6 +84,7 @@ const Sidebar = ({
     dispatch(clearMessages());
     sendTrackEvent('edx.ui.lms.learning_assistant.clear', {
       course_id: courseId,
+      ...(variationKey ? { experiment_name: experimentName, variation_key: variationKey } : {}),
     });
   };
 
diff --git a/src/components/ToggleXpertButton/index.jsx b/src/components/ToggleXpertButton/index.jsx
index 6041c9bc..f32d49f2 100644
--- a/src/components/ToggleXpertButton/index.jsx
+++ b/src/components/ToggleXpertButton/index.jsx
@@ -12,6 +12,7 @@ import {
 } from '@openedx/paragon';
 import { Close } from '@openedx/paragon/icons';
 
+import { usePromptExperiment } from '../../utils/optimizelyExperiment';
 import { ReactComponent as XpertLogo } from '../../assets/xpert-logo.svg';
 import './index.scss';
 
@@ -25,6 +26,7 @@ const ToggleXpert = ({
   const [isModalOpen, setIsModalOpen] = useState(true);
   const [target, setTarget] = useState(null);
   const { userId } = getAuthenticatedUser();
+  const [ variationKey, experimentName ] = usePromptExperiment(userId);
 
   const handleClick = (event) => {
     // log event if the tool is opened
@@ -35,6 +37,7 @@ const ToggleXpert = ({
           course_id: courseId,
           user_id: userId,
           source: event.target.id === 'toggle-button' ? 'toggle' : 'cta',
+          ...(variationKey ? { experiment_name: experimentName, variation_key: variationKey } : {}),
         },
       );
     }
@@ -51,6 +54,7 @@ const ToggleXpert = ({
     localStorage.setItem('dismissedLearningAssistantCallToAction', 'true');
     sendTrackEvent('edx.ui.lms.learning_assistant.dismiss_action_message', {
       course_id: courseId,
+      ...(variationKey ? { experiment_name: experimentName, variation_key: variationKey } : {}),
     });
   };
 
@@ -63,6 +67,7 @@ const ToggleXpert = ({
         course_id: courseId,
         user_id: userId,
         source: 'product-tour',
+        ...(variationKey ? { experiment_name: experimentName, variation_key: variationKey } : {}),
       },
     );
   };
@@ -78,7 +83,7 @@ const ToggleXpert = ({
     (!isOpen && (
       <div
         className={
-          `toggle position-fixed closed d-flex flex-column justify-content-end align-items-end mx-3 border-0 
+          `toggle position-fixed closed d-flex flex-column justify-content-end align-items-end mx-3 border-0
            ${chatMargin}`
         }
       >
diff --git a/src/data/api.js b/src/data/api.js
index ec10b41e..c2b89335 100644
--- a/src/data/api.js
+++ b/src/data/api.js
@@ -1,5 +1,6 @@
 import { getConfig, snakeCaseObject } from '@edx/frontend-platform';
-import { getAuthenticatedHttpClient } from '@edx/frontend-platform/auth';
+import { getAuthenticatedHttpClient, getAuthenticatedUser } from '@edx/frontend-platform/auth';
+import { usePromptExperiment, trackChatBotMessageOptimizely } from '../utils/optimizelyExperiment'
 
 async function fetchChatResponse(courseId, messageList, unitId) {
   const payload = messageList.map((message) => ({
@@ -7,15 +8,24 @@ async function fetchChatResponse(courseId, messageList, unitId) {
     content: message?.content,
   }));
 
+  const { userId } = getAuthenticatedUser();
+  const [ variationKey ] = usePromptExperiment(userId);
+
   let queryParams = { unitId };
+
+  if (variationKey) {
+    queryParams.responseVariation = variationKey
+    trackChatBotMessageOptimizely(userId)
+  }
+
   queryParams = snakeCaseObject(queryParams);
 
   let queryString = new URLSearchParams(queryParams);
   queryString = queryString.toString();
 
   const url = new URL(`${getConfig().CHAT_RESPONSE_URL}/${courseId}?${queryString}`);
-
   const { data } = await getAuthenticatedHttpClient().post(url.href, payload);
+
   return data;
 }
 
diff --git a/src/data/thunks.js b/src/data/thunks.js
index bdc0a7f4..20c67f3e 100644
--- a/src/data/thunks.js
+++ b/src/data/thunks.js
@@ -1,5 +1,7 @@
 import { sendTrackEvent } from '@edx/frontend-platform/analytics';
 import { getAuthenticatedUser } from '@edx/frontend-platform/auth';
+
+import { usePromptExperiment } from '../utils/optimizelyExperiment';
 import fetchChatResponse, { fetchLearningAssistantEnabled } from './api';
 import {
   setCurrentMessage,
@@ -33,6 +35,8 @@ export function addChatMessage(role, content, courseId) {
     dispatch(resetApiError());
 
     const { userId } = getAuthenticatedUser();
+    const [ variationKey, experimentName ] = usePromptExperiment(userId);
+
     sendTrackEvent('edx.ui.lms.learning_assistant.message', {
       id: conversationId,
       course_id: courseId,
@@ -40,6 +44,7 @@ export function addChatMessage(role, content, courseId) {
       timestamp: message.timestamp,
       role: message.role,
       content: message.content,
+      ...(variationKey ? { experiment_name: experimentName, variation_key: variationKey } : {}),
     });
   };
 }
diff --git a/src/utils/optimizelyExperiment.js b/src/utils/optimizelyExperiment.js
index 1d192303..d907f968 100644
--- a/src/utils/optimizelyExperiment.js
+++ b/src/utils/optimizelyExperiment.js
@@ -1,3 +1,4 @@
+import { useDecision } from '@optimizely/react-sdk'
 import optimizelyInstance from '../data/optimizely';
 
 const PRODUCT_TOUR_EXP_KEY = 'la_product_tour';
@@ -11,6 +12,17 @@ const activateProductTourExperiment = (userId) => {
   return variant === PRODUCT_TOUR_EXP_VARIATION;
 };
 
+const PROMPT_EXPERIMENT_FLAG = '_cosmo__xpert_gpt_4_0_prompt'
+const PROMPT_EXPERIMENT_KEY = 'updated_prompt'
+
+const usePromptExperiment = (userId) => {
+  const [{ enabled, variationKey }] = useDecision(PROMPT_EXPERIMENT_FLAG, { autoUpdate: true }, { id: userId })
+
+  const active = enabled && variationKey === PROMPT_EXPERIMENT_KEY
+
+  return active ? [variationKey, PROMPT_EXPERIMENT_FLAG] : []
+}
+
 const trackChatBotLaunchOptimizely = (userId, userAttributes = {}) => {
   optimizelyInstance.track('learning_assistant_chat_click', userId, userAttributes);
 };
@@ -23,4 +35,5 @@ export {
   activateProductTourExperiment,
   trackChatBotLaunchOptimizely,
   trackChatBotMessageOptimizely,
+  usePromptExperiment,
 };