diff --git a/package.json b/package.json
index 36631f51c..9aa3e9588 100644
--- a/package.json
+++ b/package.json
@@ -70,6 +70,7 @@
     "@apollo/client": "^3.2.1",
     "classnames": "^2.2.5",
     "core-js": "^3.26.1",
+    "fake-xml-http-request": "^2.1.2",
     "final-form": "^4.18.2",
     "graphql": "^16.0.0",
     "history": "^4.6.3",
@@ -80,6 +81,7 @@
     "localforage": "^1.5.6",
     "lodash": "^4.17.21",
     "moment-timezone": "^0.5.14",
+    "pretender": "^3.4.7",
     "prop-types": "^15.5.10",
     "query-string": "^7.1.2",
     "react-cookie": "^4.0.3",
@@ -96,7 +98,8 @@
     "regenerator-runtime": "^0.13.10",
     "rtl-detect": "^1.0.2",
     "rxjs": "^6.6.3",
-    "use-deep-compare": "^1.1.0"
+    "use-deep-compare": "^1.1.0",
+    "whatwg-fetch": "^3.6.19"
   },
   "peerDependencies": {
     "@folio/stripes-components": "^12.0.0",
diff --git a/src/App.js b/src/App.js
index 8d7503b59..4fd499369 100644
--- a/src/App.js
+++ b/src/App.js
@@ -11,7 +11,8 @@ import gatherActions from './gatherActions';
 import { destroyStore } from './mainActions';
 
 import Root from './components/Root';
-import { registerServiceWorker } from './serviceWorkerRegistration';
+// import { registerServiceWorker } from './serviceWorkerRegistration';
+import FolioFetch from './folio-fetch';
 
 export default class StripesCore extends Component {
   static propTypes = {
@@ -36,7 +37,8 @@ export default class StripesCore extends Component {
     // the service worker functions as a proxy between between the browser
     // and the network, intercepting ALL fetch requests to make sure they
     // are accompanied by a valid access-token.
-    registerServiceWorker(okapiConfig, config, this.logger);
+    // registerServiceWorker(okapiConfig, config, this.logger);
+    this.ffetch = new FolioFetch();
   }
 
   componentWillUnmount() {
diff --git a/src/loginServices.js b/src/loginServices.js
index b99107f93..350b26442 100644
--- a/src/loginServices.js
+++ b/src/loginServices.js
@@ -392,21 +392,21 @@ export async function logout(okapiUrl, store) {
  * @returns {Promise}
  */
 export const postTokenExpiration = (tokenExpiration) => {
-  if ('serviceWorker' in navigator && navigator.serviceWorker.controller) {
-    return navigator.serviceWorker.ready
-      .then((reg) => {
-        const sw = reg.active;
-        if (sw) {
-          const message = { source: '@folio/stripes-core', type: 'TOKEN_EXPIRATION', value: { tokenExpiration } };
-          logger.log('rtr', '<= sending', message);
-          sw.postMessage(message);
-        } else {
-          logger.log('rtr', 'error, could not send TOKEN_EXPIRATION message; no ServiceWorker is active');
-        }
-      });
-  }
-
-  logger.log('rtr', 'error, could not send TOKEN_EXPIRATION message; navigator.serviceWorker is empty');
+  // if ('serviceWorker' in navigator && navigator.serviceWorker.controller) {
+  //   return navigator.serviceWorker.ready
+  //     .then((reg) => {
+  //       const sw = reg.active;
+  //       if (sw) {
+  //         const message = { source: '@folio/stripes-core', type: 'TOKEN_EXPIRATION', value: { tokenExpiration } };
+  //         logger.log('rtr', '<= sending', message);
+  //         sw.postMessage(message);
+  //       } else {
+  //         logger.log('rtr', 'error, could not send TOKEN_EXPIRATION message; no ServiceWorker is active');
+  //       }
+  //     });
+  // }
+
+  // logger.log('rtr', 'error, could not send TOKEN_EXPIRATION message; navigator.serviceWorker is empty');
   return Promise.resolve();
 };
 
diff --git a/src/service-worker.js b/src/service-worker.js
index 0bff7a9bc..64e954c31 100644
--- a/src/service-worker.js
+++ b/src/service-worker.js
@@ -50,7 +50,12 @@
  *
  */
 
-import { okapiUrl, okapiTenant } from 'micro-stripes-config';
+import { okapi } from 'stripes-config';
+
+const {
+  url: okapiUrl,
+  tenant: okapiTenant
+} = okapi;
 
 /** { atExpires, rtExpires } both are JS millisecond timestamps */
 let tokenExpiration = null;
@@ -327,9 +332,9 @@ const passThroughWithRT = (event) => {
  * @returns Promise
  * @throws if any fetch fails
  */
-const passThroughWithAT = (event) => {
+export const passThroughWithAT = (event, handler) => {
   if (shouldLog) console.log('-- (rtr-sw)    (valid AT or authn request)');
-  return fetch(event.request, { credentials: 'include' })
+  return handler(event.request, { credentials: 'include' })
     .then(response => {
       // Handle three different situations:
       // 1. 403: AT was expired (try RTR)