diff --git a/app/src/service-worker/serviceWorker.js b/app/src/service-worker/serviceWorker.js
index d9a2567..72d1914 100644
--- a/app/src/service-worker/serviceWorker.js
+++ b/app/src/service-worker/serviceWorker.js
@@ -1,13 +1,13 @@
 import { precacheAndRoute } from "workbox-precaching";
 import { openDB } from "idb";
-import init, { Client as CoreClient } from "meal-core";
-import sqlite3InitModule from '@sqlite.org/sqlite-wasm';
+import init, { create_client } from "meal-core";
 
 /**
-* @import { Schema } from "./schema"
-* @import { Operation } from "./operation"
-*/
+ * @import { Schema } from "./schema"
+ * @import { Operation } from "./operation"
+ */
 
+// Reduce noise
 // @ts-expect-error
 self.__WB_DISABLE_DEV_LOGS = true;
 
@@ -24,23 +24,18 @@ const openDatabase = /** @type {typeof openDB<Schema>} */ (openDB)("meal", 1, {
   },
 });
 
-
 openDatabase.then((database) => {
   const transaction = database.transaction("configuration", "readwrite");
   const store = transaction.objectStore("configuration");
   if (store.add === undefined) throw new Error("Store is undefined");
 
   store.add({});
-
-})
+});
 
 /**
-*
-* @param {Operation} operation
-*/
-function handleDatabaseRequest(operation) {
-  console.debug("handle database request", arguments);
-}
+ *
+ * @returns {Promise<ArrayBuffer>}
+ */
 async function initializeClient() {
   // Get configuration
   const database = await openDatabase;
@@ -52,26 +47,57 @@ async function initializeClient() {
   // Have to use wasm-pack --target web to build the wasm package to get the init function because with the bundler target
   // it is included as a top level await which is not supported by service workers according to the web spec
   await init();
-  const client = new CoreClient(
-    configuration?.clientId,
-    configuration?.user?.name,
-    handleDatabaseRequest
+
+  // Persist client state
+  const directory = await navigator.storage.getDirectory();
+
+  const FILE_NAME = "client.meal";
+  /** @type {FileSystemFileHandle | undefined} */
+  let fileHandle;
+  try {
+    fileHandle = await directory.getFileHandle(FILE_NAME);
+  } catch (error) {
+    // Finding out if the file does not exist is a bit unergonomic
+    if (!(error instanceof DOMException) || error.name !== "NotFoundError")
+      throw error;
+
+    console.debug("No client.meal file found");
+  }
+
+  if (fileHandle !== undefined) {
+    const file = await fileHandle.getFile();
+    return await file.arrayBuffer();
+  }
+
+  const client = create_client(
+    configuration.clientId,
+    configuration.user?.name
   );
 
-  return client;
+  fileHandle = await directory.getFileHandle(FILE_NAME, {
+    create: true,
+  });
+
+  const writeStream = await fileHandle.createWritable();
+  if (client.buffer instanceof SharedArrayBuffer)
+    throw new Error("Did not expect a SharedArrayBuffer");
+
+  try {
+    await writeStream.write(client.buffer);
+  } finally {
+    writeStream.close();
+  }
+
+  console.debug("Created new client", client);
+
+  return client.buffer;
 }
 
 const setupClient = initializeClient();
 
-// const id = localStorage.getItem("id");
-// const name = localStorage.getItem("name");
-// const isOnboarded = localStorage.getItem("isOnboarded") !== null;
-// const client = new Client(id ?? undefined, name ?? undefined);
-
 /** The url for messages endpoint. Don't forget the trailing slash. */
 const messagesUrl = new URL("/messages/", self.location.origin);
 
-const broadcast = new BroadcastChannel("melt");
 /**
  * @param {MessageEvent<ServiceWorkerRequest | ServiceWorkerMessage>} event
  */
@@ -101,44 +127,44 @@ async function handleMessage(event) {
     }
     case "sendMessage": {
       const client = await setupClient;
-      const body = client.send_message(event.data.groupId, {
-        sent: event.data.sent.toISOString(),
-        text: event.data.text,
-      });
-      const url = new URL(event.data.friendId, messagesUrl);
-      const request = new Request(url, {
-        method: "post",
-        headers: {
-          //https://www.rfc-editor.org/rfc/rfc9420.html#name-the-message-mls-media-type
-          "Content-Type": "message/mls",
-        },
-        body,
-      });
-
-      //TODO error handling
-      //TODO retry
-      await fetch(request);
+      // const body = client.send_message(event.data.groupId, {
+      //   sent: event.data.sent.toISOString(),
+      //   text: event.data.text,
+      // });
+      // const url = new URL(event.data.friendId, messagesUrl);
+      // const request = new Request(url, {
+      //   method: "post",
+      //   headers: {
+      //     //https://www.rfc-editor.org/rfc/rfc9420.html#name-the-message-mls-media-type
+      //     "Content-Type": "message/mls",
+      //   },
+      //   body,
+      // });
+
+      // //TODO error handling
+      // //TODO retry
+      // await fetch(request);
       return;
     }
     case "createInvite": {
       const client = await setupClient;
-      const encodedInvite = client.create_invite(client.get_name());
-      const inviteUrl = new URL(`/join/${encodedInvite}`, location.origin);
-
-      if (event.source === null)
-        throw new Error(
-          "Expected browser context source to send invite url back to"
-        );
-
-      if (!(event.source instanceof Client))
-        throw new Error("Expected message event source to be a client");
-
-      /** @type {ServiceWorkerResponse} */
-      const response = {
-        type: "inviteUrl",
-        inviteUrl: inviteUrl.href,
-      };
-      event.ports[0].postMessage(response);
+      // const encodedInvite = client.create_invite(client.get_name());
+      // const inviteUrl = new URL(`/join/${encodedInvite}`, location.origin);
+
+      // if (event.source === null)
+      //   throw new Error(
+      //     "Expected browser context source to send invite url back to"
+      //   );
+
+      // if (!(event.source instanceof Client))
+      //   throw new Error("Expected message event source to be a client");
+
+      // /** @type {ServiceWorkerResponse} */
+      // const response = {
+      //   type: "inviteUrl",
+      //   inviteUrl: inviteUrl.href,
+      // };
+      // event.ports[0].postMessage(response);
       return;
     }
     case "inviteFromPackage": {