diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e14d00b..d52f97d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,6 +31,7 @@ jobs:
       - name: Install Dependencies
         if: steps.cache.outputs.cache-hit != 'true'
         run: npm ci --ignore-scripts
+      - run: npm run check
       - run: npm run build
       - name: Publish package to NPM
         if: startsWith(github.ref, 'refs/tags/v')
diff --git a/.gitignore b/.gitignore
index f06235c..4241c17 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 node_modules
 dist
+*~
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bef1c52..a4cf36c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -404,8 +404,6 @@ release date when you use `npm version` (see `README.md`).
 [0.15.0]: https://github.com/webxdc/webxdc-dev/tree/v0.15.0
 [unreleased]: https://github.com/webxdc/webxdc-dev/compare/v0.15.1...HEAD
 [0.15.1]: https://github.com/webxdc/webxdc-dev/tree/v0.15.1
-
-
 [Unreleased]: https://github.com/webxdc/webxdc-dev/compare/v0.18.0...HEAD
 [0.18.0]: https://github.com/webxdc/webxdc-dev/compare/v0.17.0...v0.18.0
 [0.17.0]: https://github.com/webxdc/webxdc-dev/compare/v0.16.0...v0.17.0
diff --git a/README.md b/README.md
index d78db53..9939cc5 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 # webxdc-dev
 
 [![CI](https://github.com/webxdc/webxdc-dev/actions/workflows/ci.yml/badge.svg)](https://github.com/webxdc/webxdc-dev/actions/workflows/ci.yml)
+[![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier)
 
 webxdc-dev is a development server for [webxdc apps](https://webxdc.org).
 Easily test your app's behavior as if it was shared in a real chat with
@@ -8,7 +9,6 @@ multiple people.
 
 ![example screenshot](https://raw.githubusercontent.com/webxdc/webxdc-dev/main/screenshot.png)
 
-
 In contrast to [hello](https://github.com/webxdc/hello), each "user"'s app
 instance gets its own isolated state (e.g. `localStorage`), since each is
 served from a separate port (therefore a separate origin).
@@ -80,7 +80,7 @@ to see full information. You can also filter messages. There is also a "chat"
 tab which you can use to see `info` contained in updates as well as any
 `summary` text contained in an update.
 
-The sidebar can be closed with `Close Messages` button within the sidebar and 
+The sidebar can be closed with `Close Messages` button within the sidebar and
 expanded by clicking on `Open Messages` within the devices tab.
 The sidebars width can also be adjusted by moving the separating line between
 devices and sidebar.
diff --git a/TODO.md b/TODO.md
index 5668d0d..f039eac 100644
--- a/TODO.md
+++ b/TODO.md
@@ -16,7 +16,7 @@
 ## Node version
 
 - Can I warn when the node version is too old upon installation.
-	
+
 ## Messages
 
 - Perhaps default message filter should see connect & sent at the same time?
diff --git a/backend/app.ts b/backend/app.ts
index 7349a42..a0e1365 100644
--- a/backend/app.ts
+++ b/backend/app.ts
@@ -29,7 +29,7 @@ export function createFrontend(
   appInfo: AppInfo,
   instances: Instances,
   injectFrontend: InjectExpress,
-  getIndexHtml: () => string
+  getIndexHtml: () => string,
 ): expressWs.Application {
   const expressApp = express();
   const wsInstance = expressWs(expressApp);
@@ -57,9 +57,7 @@ export function createFrontend(
     res.send(appInfo.icon.buffer);
   });
   app.get<{}, Instance[]>("/instances", (req, res) => {
-    res.json(
-      instances.list()
-    );
+    res.json(instances.list());
   });
   app.post<{}, Instance>("/instances", (req, res) => {
     const instance = instances.add();
@@ -71,9 +69,9 @@ export function createFrontend(
       color: instance.color,
     });
   });
-  app.delete<{id: string}, Instance[]>("/instances/:id", (req, res) => {
+  app.delete<{ id: string }, Instance[]>("/instances/:id", (req, res) => {
     instances.delete(parseInt(req.params.id));
-    res.json(instances.list())
+    res.json(instances.list());
   });
 
   app.post<{}, { status: string }>("/clear", (req, res) => {
@@ -126,7 +124,7 @@ export function createPeer(options: PeerOptions): expressWs.Instance {
     wsInstance.app.use((req, res, next) => {
       const contentSecurityPolicy = getContentSecurityPolicy(
         location,
-        options.instanceUrl
+        options.instanceUrl,
       );
       res.setHeader("Content-Security-Policy", contentSecurityPolicy);
       next();
@@ -144,7 +142,7 @@ export function createPeer(options: PeerOptions): expressWs.Instance {
       createProxyMiddleware(filter, {
         target: location.url,
         ws: false,
-      })
+      }),
     );
   } else {
     // serve webxdc project from directory
@@ -155,7 +153,7 @@ export function createPeer(options: PeerOptions): expressWs.Instance {
 
 function getContentSecurityPolicy(
   location: Location,
-  instanceUrl: string
+  instanceUrl: string,
 ): string {
   const connectSrcUrls = [];
 
@@ -180,7 +178,7 @@ function getContentSecurityPolicy(
 
   return policy.replace(
     /connect-src (.*?);/,
-    `connect-src $1 ${connectSrcUrls.join(" ")} ;`
+    `connect-src $1 ${connectSrcUrls.join(" ")} ;`,
   );
 }
 
diff --git a/backend/appInfo.test.ts b/backend/appInfo.test.ts
index d53067e..7c1807b 100644
--- a/backend/appInfo.test.ts
+++ b/backend/appInfo.test.ts
@@ -17,7 +17,7 @@ test("minimal directory app info", async () => {
 
 test("directory app info with manifest", async () => {
   const location = getLocation(
-    path.resolve(__dirname, "fixtures", "withManifest")
+    path.resolve(__dirname, "fixtures", "withManifest"),
   );
   const appInfo = await getAppInfo(location);
   expect(appInfo.location).toEqual(location);
@@ -31,7 +31,7 @@ test("directory app info with manifest", async () => {
 
 test("directory app info with manifest but no name entry", async () => {
   const location = getLocation(
-    path.resolve(__dirname, "fixtures", "withManifestWithoutName")
+    path.resolve(__dirname, "fixtures", "withManifestWithoutName"),
   );
   const appInfo = await getAppInfo(location);
   expect(appInfo.location).toEqual(location);
@@ -64,7 +64,7 @@ test("directory app info with manifest but no name entry", async () => {
 
 test("directory app info with jpg icon", async () => {
   const location = getLocation(
-    path.resolve(__dirname, "fixtures", "withJpgIcon")
+    path.resolve(__dirname, "fixtures", "withJpgIcon"),
   );
   const appInfo = await getAppInfo(location);
   expect(appInfo.location).toEqual(location);
@@ -83,7 +83,7 @@ test("directory app info with jpg icon", async () => {
 
 test("directory app info with png icon", async () => {
   const location = getLocation(
-    path.resolve(__dirname, "fixtures", "withPngIcon")
+    path.resolve(__dirname, "fixtures", "withPngIcon"),
   );
   const appInfo = await getAppInfo(location);
   expect(appInfo.location).toEqual(location);
@@ -210,7 +210,7 @@ test("url app info with broken manifest", async () => {
   } catch (e) {
     if (e instanceof AppInfoError) {
       expect(e.message).toEqual(
-        "Invalid manifest.toml, please check the format"
+        "Invalid manifest.toml, please check the format",
       );
     } else {
       throw e;
diff --git a/backend/appInfo.ts b/backend/appInfo.ts
index c683686..75987b8 100644
--- a/backend/appInfo.ts
+++ b/backend/appInfo.ts
@@ -49,7 +49,7 @@ export async function getAppInfo(location: Location): Promise<AppInfo> {
 
 export async function getAppInfoUrl(
   location: UrlLocation,
-  fetch: typeof nodeFetch
+  fetch: typeof nodeFetch,
 ): Promise<AppInfo> {
   return {
     location,
@@ -65,7 +65,7 @@ export function getToolVersion(): string {
 
 async function getManifestInfoFromUrl(
   url: string,
-  fetch: typeof nodeFetch
+  fetch: typeof nodeFetch,
 ): Promise<ManifestInfo> {
   if (!url.endsWith("/")) {
     url = url + "/";
@@ -89,7 +89,7 @@ async function getManifestInfoFromUrl(
 
 async function getIconInfoFromUrl(
   url: string,
-  fetch: typeof nodeFetch
+  fetch: typeof nodeFetch,
 ): Promise<IconInfo | null> {
   if (!url.endsWith("/")) {
     url = url + "/";
@@ -113,7 +113,7 @@ async function getIconInfoFromUrl(
 
 function getManifestInfoFromDir(
   dir: string,
-  fallbackName: string
+  fallbackName: string,
 ): ManifestInfo {
   const tomlBuffer = readFileBuffer(path.join(dir, "manifest.toml"));
   if (tomlBuffer === null) {
@@ -165,7 +165,7 @@ function readFileBuffer(location: string): Buffer | null {
 
 async function readUrlBuffer(
   url: string,
-  fetch: typeof nodeFetch
+  fetch: typeof nodeFetch,
 ): Promise<Buffer | null> {
   const response = await fetch(url);
   if (!response.ok) {
diff --git a/backend/fixtures/minimal/index.html b/backend/fixtures/minimal/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/minimal/index.html
+++ b/backend/fixtures/minimal/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/fixtures/notXdcDir.xdc/index.html b/backend/fixtures/notXdcDir.xdc/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/notXdcDir.xdc/index.html
+++ b/backend/fixtures/notXdcDir.xdc/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/fixtures/withJpgIcon/index.html b/backend/fixtures/withJpgIcon/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/withJpgIcon/index.html
+++ b/backend/fixtures/withJpgIcon/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/fixtures/withManifest/index.html b/backend/fixtures/withManifest/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/withManifest/index.html
+++ b/backend/fixtures/withManifest/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/fixtures/withManifestWithoutName/index.html b/backend/fixtures/withManifestWithoutName/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/withManifestWithoutName/index.html
+++ b/backend/fixtures/withManifestWithoutName/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/fixtures/withPngIcon/index.html b/backend/fixtures/withPngIcon/index.html
index 50a010e..a2728bd 100644
--- a/backend/fixtures/withPngIcon/index.html
+++ b/backend/fixtures/withPngIcon/index.html
@@ -1,3 +1,5 @@
 <html>
-    <body>Hello, world!</body>
-</html>
\ No newline at end of file
+  <body>
+    Hello, world!
+  </body>
+</html>
diff --git a/backend/instance.ts b/backend/instance.ts
index 0741e6a..cb35791 100644
--- a/backend/instance.ts
+++ b/backend/instance.ts
@@ -7,7 +7,7 @@ import { Location } from "./location";
 import { createPeer, InjectExpress } from "./app";
 import { AppInfo } from "./appInfo";
 import { getColorForId } from "./color";
-import { Instance as FrontendInstance } from '../types/instance';
+import { Instance as FrontendInstance } from "../types/instance";
 
 export type Options = {
   basePort: number;
@@ -39,7 +39,7 @@ class Instance {
     public app: expressWs.Application,
     public port: number,
     public url: string,
-    public webXdc: WebXdcMulti
+    public webXdc: WebXdcMulti,
   ) {
     this.id = port.toString();
     this.color = getColorForId(this.id);
@@ -52,7 +52,7 @@ class Instance {
   }
 
   close() {
-    this.server.close()
+    this.server.close();
   }
 }
 
@@ -107,7 +107,7 @@ export class Instances {
       app,
       port,
       instanceUrl,
-      this.processor.createClient(port.toString())
+      this.processor.createClient(port.toString()),
     );
 
     const wss = wsInstance.getWss();
@@ -117,7 +117,7 @@ export class Instances {
       ws.on("message", (msg: string) => {
         if (typeof msg !== "string") {
           console.error(
-            "webxdc: Don't know how to handle unexpected non-string data"
+            "webxdc: Don't know how to handle unexpected non-string data",
           );
           return;
         }
@@ -133,7 +133,7 @@ export class Instances {
                 JSON.stringify({
                   type: "updates",
                   updates: updates.map(([update]) => update),
-                })
+                }),
               );
             },
             parsed.serial,
@@ -152,7 +152,7 @@ export class Instances {
                 name: this.appInfo.manifest.name,
                 color: instance.color,
               },
-            })
+            }),
           );
         } else {
           throw new Error(`Unknown message: ${JSON.stringify(parsed)}`);
@@ -166,7 +166,9 @@ export class Instances {
   delete(id: number) {
     let instance = this.instances.get(id);
     if (instance == null) {
-      throw new Error(`Instance with id ${id} can't be deleted because it does not exist`);
+      throw new Error(
+        `Instance with id ${id} can't be deleted because it does not exist`,
+      );
     }
     instance.close();
     this.processor.removeClient(instance.id);
@@ -187,13 +189,13 @@ export class Instances {
     this._onMessage = onMessage;
   }
 
-  list(): FrontendInstance[]{
+  list(): FrontendInstance[] {
     return Array.from(this.instances.values()).map((instance) => ({
       id: instance.id,
       port: instance.port,
       url: instance.url,
       color: instance.color,
-    }))
+    }));
   }
 }
 
@@ -215,7 +217,7 @@ function isSendUpdateMessage(value: any): value is SendUpdateMessage {
 }
 
 function isSetUpdateListenerMessage(
-  value: any
+  value: any,
 ): value is SetUpdateListenerMessage {
   return value.type === "setUpdateListener";
 }
diff --git a/backend/location.ts b/backend/location.ts
index f1a21eb..a431140 100644
--- a/backend/location.ts
+++ b/backend/location.ts
@@ -45,7 +45,7 @@ export function getLocation(location: string): Location {
     }
     if (!hasIndexHtml(path)) {
       throw new LocationError(
-        `Invalid xdc file (no index.html file inside): ${location}`
+        `Invalid xdc file (no index.html file inside): ${location}`,
       );
     }
     return {
@@ -65,7 +65,7 @@ export function getLocation(location: string): Location {
 
   if (!hasIndexHtml(location)) {
     throw new LocationError(
-      `Invalid xdc dir (no index.html file): ${location}`
+      `Invalid xdc dir (no index.html file): ${location}`,
     );
   }
   return {
diff --git a/backend/message.test.ts b/backend/message.test.ts
index 164d85f..f6a1ec0 100644
--- a/backend/message.test.ts
+++ b/backend/message.test.ts
@@ -327,7 +327,7 @@ test("clear single client", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
   // we always clear on first connection with a new processor
   expect(client0Cleared).toMatchObject(["cleared"]);
@@ -343,7 +343,7 @@ test("clear single client", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
   expect(client0Cleared).toMatchObject(["cleared", "cleared"]);
 });
@@ -362,7 +362,7 @@ test("clear multiple clients", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   client1.connect(
@@ -371,7 +371,7 @@ test("clear multiple clients", () => {
     () => {
       client1Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Cleared).toMatchObject(["cleared"]);
@@ -389,7 +389,7 @@ test("clear multiple clients", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
   expect(client0Cleared).toMatchObject(["cleared", "cleared"]);
 });
@@ -407,7 +407,7 @@ test("clear client that is created later", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Cleared).toMatchObject(["cleared"]);
@@ -422,7 +422,7 @@ test("clear client that is created later", () => {
     () => {
       client1Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Cleared).toMatchObject(["cleared", "cleared"]);
@@ -444,7 +444,7 @@ test("clear multiple clients, multiple times", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   client1.connect(
@@ -453,7 +453,7 @@ test("clear multiple clients, multiple times", () => {
     () => {
       client1Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Cleared).toMatchObject(["cleared"]);
@@ -482,7 +482,7 @@ test("connect with clear means we get no catchup if no new updates", () => {
     () => {
       client0Heard.push("cleared");
       return true;
-    }
+    },
   );
 
   client0.sendUpdate({ payload: "Hello" }, "update");
@@ -511,7 +511,7 @@ test("connect with clear means we get no catchup if no new updates", () => {
     () => {
       client1Heard.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Heard).toMatchObject([
@@ -540,7 +540,7 @@ test("connect with clear means catchup only with updates after clear", () => {
     () => {
       client0Heard.push("cleared");
       return true;
-    }
+    },
   );
 
   client0.sendUpdate({ payload: "Hello" }, "update");
@@ -572,7 +572,7 @@ test("connect with clear means catchup only with updates after clear", () => {
     () => {
       client1Heard.push("cleared");
       return true;
-    }
+    },
   );
 
   expect(client0Heard).toMatchObject([
@@ -699,7 +699,7 @@ test("clear other client but was disconnected", () => {
     () => {
       client0Cleared.push("cleared");
       return true;
-    }
+    },
   );
 
   client1.connect(
@@ -708,7 +708,7 @@ test("clear other client but was disconnected", () => {
     () => {
       // we never got the clear
       return false;
-    }
+    },
   );
 
   expect(client0Cleared).toMatchObject(["cleared"]);
diff --git a/backend/message.ts b/backend/message.ts
index b6464fb..c41bcab 100644
--- a/backend/message.ts
+++ b/backend/message.ts
@@ -8,7 +8,7 @@ import type { Message } from "../types/message";
 import { getColorForId } from "./color";
 
 type UpdateListenerMulti = (
-  updates: [ReceivedUpdate<JsonValue>, string][]
+  updates: [ReceivedUpdate<JsonValue>, string][],
 ) => boolean;
 
 type ClearListener = () => boolean;
@@ -42,7 +42,10 @@ class Client implements WebXdcMulti {
   updateSerial: number | null = null;
   deleteListener: DeleteListener | null = null;
 
-  constructor(public processor: Processor, public id: string) {}
+  constructor(
+    public processor: Processor,
+    public id: string,
+  ) {}
 
   sendUpdate(update: Update<JsonValue>, descr: string): void {
     this.processor.distribute(this.id, update, descr);
@@ -124,10 +127,10 @@ class Client implements WebXdcMulti {
 
   // sends a message to the all clients to shut down
   delete() {
-    if ( this.deleteListener == null ) {
+    if (this.deleteListener == null) {
       return;
     }
-    this.deleteListener()
+    this.deleteListener();
   }
 }
 
@@ -186,7 +189,10 @@ class Processor implements IProcessor {
     updateListener(
       this.updates
         .slice(serial)
-        .map(([update, descr]) => [{ ...update, max_serial: maxSerial }, descr])
+        .map(([update, descr]) => [
+          { ...update, max_serial: maxSerial },
+          descr,
+        ]),
     );
   }
 }
diff --git a/backend/program.ts b/backend/program.ts
index 171a34e..10e07ee 100644
--- a/backend/program.ts
+++ b/backend/program.ts
@@ -25,28 +25,28 @@ export function createProgram(inject: Inject): Command {
     .command("run")
     .argument(
       "<location>",
-      "URL with dev server, path to .xdc file, or path to webxdc dist directory"
+      "URL with dev server, path to .xdc file, or path to webxdc dist directory",
     )
     .option(
       "-p, --port <port>",
       "start port for webxdc-dev UI, instance ports are incremented by one each",
       parsePort,
-      7000
+      7000,
     )
     .option("--no-csp", "run instances without CSP applied")
     .option(
       "-v, --verbose",
       "Print all messages sent and received by instances",
-      false
+      false,
     )
     .description(
-      "Run webxdc-dev simulator with webxdc from dev server URL, .xdc file or dist directory"
+      "Run webxdc-dev simulator with webxdc from dev server URL, .xdc file or dist directory",
     )
     .action((location, options) => {
       run(
         location,
         { basePort: options.port, csp: options.csp, verbose: options.verbose },
-        inject
+        inject,
       );
     });
   return program;
diff --git a/backend/run.ts b/backend/run.ts
index 7996df2..2c06417 100644
--- a/backend/run.ts
+++ b/backend/run.ts
@@ -25,7 +25,7 @@ function actualRun(appInfo: AppInfo, options: Options, inject: Inject): void {
     appInfo,
     instances,
     injectFrontend,
-    getIndexHtml
+    getIndexHtml,
   );
 
   frontend.listen(options.basePort, () => {
diff --git a/backend/unpack.ts b/backend/unpack.ts
index 30ad430..3365c83 100644
--- a/backend/unpack.ts
+++ b/backend/unpack.ts
@@ -17,7 +17,7 @@ export function withTempDir(fn: (tmpDir: string) => void) {
       fs.rmSync(tmpDir, { recursive: true });
     } catch (e) {
       console.error(
-        `An error has occurred while removing the temp dir at ${tmpDir}. Error: ${e}`
+        `An error has occurred while removing the temp dir at ${tmpDir}. Error: ${e}`,
       );
     }
   }
diff --git a/frontend/App.tsx b/frontend/App.tsx
index 3f12fa0..4180395 100644
--- a/frontend/App.tsx
+++ b/frontend/App.tsx
@@ -54,7 +54,12 @@ const App: Component = () => {
           <Tab>Main</Tab>
           <Tab>Info</Tab>
         </TabList>
-        <TabPanel flexGrow="1" display="flex" justifyContent="center" maxHeight="calc(100vh - 40px)">
+        <TabPanel
+          flexGrow="1"
+          display="flex"
+          justifyContent="center"
+          maxHeight="calc(100vh - 40px)"
+        >
           <AppRoutes />
         </TabPanel>
         <TabPanel>
diff --git a/frontend/InstanceHeader.tsx b/frontend/InstanceHeader.tsx
index b19657f..ebd7d1b 100644
--- a/frontend/InstanceHeader.tsx
+++ b/frontend/InstanceHeader.tsx
@@ -1,5 +1,12 @@
 import { Component, Show, createMemo, JSX, Accessor } from "solid-js";
-import { Flex, Text, Badge, Tooltip, IconButton, notificationService } from "@hope-ui/solid";
+import {
+  Flex,
+  Text,
+  Badge,
+  Tooltip,
+  IconButton,
+  notificationService,
+} from "@hope-ui/solid";
 import { IoRefreshOutline, IoStop, IoPlay } from "solid-icons/io";
 import { FiExternalLink, FiTrash } from "solid-icons/fi";
 
@@ -20,14 +27,15 @@ const InstanceHeader: Component<{
   });
 
   const handleRemoveInstance = async (id: string) => {
-    let new_instances = await (await fetch(`/instances/${id}`, { method: "DELETE" })).json()
+    let new_instances = await (
+      await fetch(`/instances/${id}`, { method: "DELETE" })
+    ).json();
     mutateInstances(new_instances);
     notificationService.show({
       title: `Deleted instance ${id}`,
     });
   };
 
-
   const receivedCount = createMemo(() => {
     return received(props.instance.id);
   });
@@ -39,7 +47,6 @@ const InstanceHeader: Component<{
   return (
     <Flex gap="$1" justifyContent="space-between" alignItems="center">
       <Tooltip label="Click to see all messages for this instance">
-
         <Text
           cursor="pointer"
           color={props.instance.color}
diff --git a/frontend/InstancesButtons.tsx b/frontend/InstancesButtons.tsx
index c7979cc..169b9f2 100644
--- a/frontend/InstancesButtons.tsx
+++ b/frontend/InstancesButtons.tsx
@@ -42,12 +42,18 @@ const InstancesButtons: Component<{
 
   return (
     <Flex direction="row" justifyContent="flex-start" gap="$3">
-      <Button colorScheme="neutral" size="xs" onClick={handleAddInstance}>Add Instance</Button>
+      <Button colorScheme="neutral" size="xs" onClick={handleAddInstance}>
+        Add Instance
+      </Button>
       <Tooltip label={CLEAR_INFO}>
-        <Button colorScheme="neutral" size="xs" onClick={handleClear}>Reset</Button>
+        <Button colorScheme="neutral" size="xs" onClick={handleClear}>
+          Reset
+        </Button>
       </Tooltip>
-      <Show when={props.show_messages_button} >
-        <Button colorScheme="neutral" size="xs" onClick={props.onOpenMessages}>Open Messages</Button>
+      <Show when={props.show_messages_button}>
+        <Button colorScheme="neutral" size="xs" onClick={props.onOpenMessages}>
+          Open Messages
+        </Button>
       </Show>
     </Flex>
   );
diff --git a/frontend/Main.tsx b/frontend/Main.tsx
index fe246c9..55b62a1 100644
--- a/frontend/Main.tsx
+++ b/frontend/Main.tsx
@@ -1,11 +1,5 @@
 import { Component, For, createSignal, Setter, Show } from "solid-js";
-import {
-  Flex,
-  Box,
-  createDisclosure,
-  Heading,
-  Button,
-} from "@hope-ui/solid";
+import { Flex, Box, createDisclosure, Heading, Button } from "@hope-ui/solid";
 
 import { instances } from "./store";
 import InstancesButtons from "./InstancesButtons";
@@ -29,9 +23,11 @@ const Main: Component = () => {
   return (
     <>
       {
-        <Show when={isOpen()} fallback={
-          <Flex>
-            <Flex flexDirection="column">
+        <Show
+          when={isOpen()}
+          fallback={
+            <Flex>
+              <Flex flexDirection="column">
                 <Flex mb="$1" justifyContent="space-between">
                   <Heading level="1">Devices</Heading>
                   <InstancesButtons
@@ -42,18 +38,22 @@ const Main: Component = () => {
                     onOpenMessages={onOpen}
                   />
                 </Flex>
-                <Box overflow="auto" >
+                <Box overflow="auto">
                   <Flex flexWrap="wrap" gap="$5" justifyContent="center">
                     <For each={instances()}>
                       {(instance: InstanceData) => (
-                        <Instance instance={instance} setSearch={setSearchAndOpen} />
+                        <Instance
+                          instance={instance}
+                          setSearch={setSearchAndOpen}
+                        />
                       )}
                     </For>
                   </Flex>
                 </Box>
               </Flex>
             </Flex>
-          }>
+          }
+        >
           <SplitView>
             <Flex flexDirection="column">
               <Flex mb="$1" justifyContent="space-between">
@@ -66,11 +66,14 @@ const Main: Component = () => {
                   onOpenMessages={() => {}}
                 />
               </Flex>
-              <Box overflow="auto" >
+              <Box overflow="auto">
                 <Flex flexWrap="wrap" gap="$5" justifyContent="center">
                   <For each={instances()}>
                     {(instance: InstanceData) => (
-                      <Instance instance={instance} setSearch={setSearchAndOpen} />
+                      <Instance
+                        instance={instance}
+                        setSearch={setSearchAndOpen}
+                      />
                     )}
                   </For>
                 </Flex>
@@ -78,8 +81,13 @@ const Main: Component = () => {
             </Flex>
             <Flex direction="column">
               <Flex justifyContent="space-between" marginBottom="$1">
-                <Heading display="inline-block" level="1" mb="1">Messages</Heading>
-                <Button colorScheme="neutral" size="xs" onClick={onClose}> Close Messages </Button>
+                <Heading display="inline-block" level="1" mb="1">
+                  Messages
+                </Heading>
+                <Button colorScheme="neutral" size="xs" onClick={onClose}>
+                  {" "}
+                  Close Messages{" "}
+                </Button>
               </Flex>
               <Sidebar search={search} setSearch={setSearchAndOpen} />
             </Flex>
diff --git a/frontend/RecordRow.tsx b/frontend/RecordRow.tsx
index 3177833..15dfcf1 100644
--- a/frontend/RecordRow.tsx
+++ b/frontend/RecordRow.tsx
@@ -2,7 +2,7 @@ import { Component, JSX } from "solid-js";
 import { Tr, Td } from "@hope-ui/solid";
 
 const RecordRow: Component<{ label: string; children: JSX.Element }> = (
-  props
+  props,
 ) => {
   return (
     <Tr>
diff --git a/frontend/SplitView.tsx b/frontend/SplitView.tsx
index 7c5f368..3bbefa2 100644
--- a/frontend/SplitView.tsx
+++ b/frontend/SplitView.tsx
@@ -1,71 +1,94 @@
-
 import { Box } from "@hope-ui/solid";
 import { Accessor } from "solid-js";
-import { createMemo, ParentComponent, Component, JSX, createSignal, children } from "solid-js";
+import {
+  createMemo,
+  ParentComponent,
+  Component,
+  JSX,
+  createSignal,
+  children,
+} from "solid-js";
 import { ResolvedJSXElement } from "solid-js/types/reactive/signal";
 
 let x = 0;
 let initialLeftWidth = 0;
-const SplitView: ParentComponent<{
-}> = (props) => {
-
-    // Somehow using `HtmlElement` here causes a type error
-    let leftSide: any;
-    let rightSide: any;
-    let resizer: any;
-
-
-    const resolvedChildren = children(() => props.children) as Accessor<ResolvedJSXElement[]>;
-
-    let [isResizing, setIsResizing] = createSignal(false);
-    let [leftWidth, setLeftWidth] = createSignal(60);
-    let leftStyleGet = createMemo(() => {
-      return {
-        width: leftWidth() + "%",
-        "user-select": isResizing() ? "none" : "user-select",
-        "pointer-event": isResizing() ? "none" : "pointer-events"
-      }
-    })
-    let rightStyleGet = createMemo(() => {
-      return {
-        "user-select": isResizing() ? "none" : "user-select",
-        "pointer-event": isResizing() ? "none" : "pointer-events"
-      }
-    })
-    let resizerStyleGet = createMemo(() => {
-      return isResizing() ? {cursor: 'col-resize'} : undefined
-    })
-
+const SplitView: ParentComponent<{}> = (props) => {
+  // Somehow using `HtmlElement` here causes a type error
+  let leftSide: any;
+  let rightSide: any;
+  let resizer: any;
 
-    function mouseMoveHandler(e: MouseEvent) {
-      const dx = e.clientX - x;
-      setLeftWidth(((initialLeftWidth + dx) * 100) / (resizer.parentNode as HTMLElement).getBoundingClientRect().width)
-      document.body.style.cursor = 'col-resize';
-    };
+  const resolvedChildren = children(() => props.children) as Accessor<
+    ResolvedJSXElement[]
+  >;
 
-    function mouseUpHandler () {
-      setIsResizing(false);
-      document.body.style.removeProperty('cursor');
-      document.removeEventListener('mousemove', mouseMoveHandler);
-      document.removeEventListener('mouseup', mouseUpHandler);
+  let [isResizing, setIsResizing] = createSignal(false);
+  let [leftWidth, setLeftWidth] = createSignal(60);
+  let leftStyleGet = createMemo(() => {
+    return {
+      width: leftWidth() + "%",
+      "user-select": isResizing() ? "none" : "user-select",
+      "pointer-event": isResizing() ? "none" : "pointer-events",
     };
-
-    function mouseDownHandler(e: MouseEvent) {
-      x = e.clientX;
-      initialLeftWidth = leftSide.getBoundingClientRect().width;
-      setIsResizing(true);
-      document.addEventListener('mousemove', mouseMoveHandler);
-      document.addEventListener('mouseup', mouseUpHandler);
+  });
+  let rightStyleGet = createMemo(() => {
+    return {
+      "user-select": isResizing() ? "none" : "user-select",
+      "pointer-event": isResizing() ? "none" : "pointer-events",
     };
+  });
+  let resizerStyleGet = createMemo(() => {
+    return isResizing() ? { cursor: "col-resize" } : undefined;
+  });
 
-    return (
-      <Box h="$full" class="splitview-container">
-        <div class="splitview-container-left" style={leftStyleGet()} ref={leftSide}>{resolvedChildren()[0]}</div>
-        <div class="splitview-resizer" style={resizerStyleGet()} ref={resizer} onMouseDown={mouseDownHandler}></div>
-        <div class="splitview-container-right" style={rightStyleGet()}  ref={rightSide}>{resolvedChildren()[1]}</div>
-      </Box>
+  function mouseMoveHandler(e: MouseEvent) {
+    const dx = e.clientX - x;
+    setLeftWidth(
+      ((initialLeftWidth + dx) * 100) /
+        (resizer.parentNode as HTMLElement).getBoundingClientRect().width,
     );
+    document.body.style.cursor = "col-resize";
+  }
+
+  function mouseUpHandler() {
+    setIsResizing(false);
+    document.body.style.removeProperty("cursor");
+    document.removeEventListener("mousemove", mouseMoveHandler);
+    document.removeEventListener("mouseup", mouseUpHandler);
+  }
+
+  function mouseDownHandler(e: MouseEvent) {
+    x = e.clientX;
+    initialLeftWidth = leftSide.getBoundingClientRect().width;
+    setIsResizing(true);
+    document.addEventListener("mousemove", mouseMoveHandler);
+    document.addEventListener("mouseup", mouseUpHandler);
+  }
+
+  return (
+    <Box h="$full" class="splitview-container">
+      <div
+        class="splitview-container-left"
+        style={leftStyleGet()}
+        ref={leftSide}
+      >
+        {resolvedChildren()[0]}
+      </div>
+      <div
+        class="splitview-resizer"
+        style={resizerStyleGet()}
+        ref={resizer}
+        onMouseDown={mouseDownHandler}
+      ></div>
+      <div
+        class="splitview-container-right"
+        style={rightStyleGet()}
+        ref={rightSide}
+      >
+        {resolvedChildren()[1]}
+      </div>
+    </Box>
+  );
 };
 
 export default SplitView;
-
diff --git a/frontend/index.html b/frontend/index.html
index 37c146e..6af3a9d 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+<!doctype html>
 <html lang="en">
   <head>
     <meta charset="utf-8" />
@@ -8,31 +8,31 @@
 
     <style>
       .splitview-container {
-          display: flex;
-          border: 1px solid #cbd5e0;
-          width: 100%;
+        display: flex;
+        border: 1px solid #cbd5e0;
+        width: 100%;
       }
       .splitview-container-left {
-          width: 60%;
-          min-width: 440px;
-          display: flex;
-          overflow: none;
-          padding: 5px;
+        width: 60%;
+        min-width: 440px;
+        display: flex;
+        overflow: none;
+        padding: 5px;
       }
       .splitview-resizer {
-          background-color: #cbd5e0;
-          cursor: ew-resize;
-          height: 100%;
-          width: 5px;
+        background-color: #cbd5e0;
+        cursor: ew-resize;
+        height: 100%;
+        width: 5px;
       }
       .splitview-container-right {
-          flex: 1;
-          display: flex;
-          padding: 5px;
-          height: 100%;
-          min-width: 450px;
+        flex: 1;
+        display: flex;
+        padding: 5px;
+        height: 100%;
+        min-width: 450px;
       }
-  </style>
+    </style>
   </head>
   <body>
     <noscript>You need to enable JavaScript to run this app.</noscript>
diff --git a/frontend/index.tsx b/frontend/index.tsx
index 10b0347..64914cf 100644
--- a/frontend/index.tsx
+++ b/frontend/index.tsx
@@ -25,5 +25,5 @@ render(
       </HopeProvider>
     </Router>
   ),
-  document.getElementById("root") as HTMLElement
+  document.getElementById("root") as HTMLElement,
 );
diff --git a/frontend/store.ts b/frontend/store.ts
index adfda0f..5e5d7fb 100644
--- a/frontend/store.ts
+++ b/frontend/store.ts
@@ -41,7 +41,7 @@ export function addMessage(message: Message): void {
   setState(
     produce((s) => {
       s.push(message);
-    })
+    }),
   );
 }
 
@@ -80,7 +80,7 @@ export function getMessages(search: Search): Message[] {
     (message) =>
       (instanceId == null || message.instanceId === instanceId) &&
       (type == null || message.type === type) &&
-      (!info || (isUpdateMessage(message) && hasText(message.update.info)))
+      (!info || (isUpdateMessage(message) && hasText(message.update.info))),
   );
 }
 
diff --git a/package-lock.json b/package-lock.json
index 86ef7b6..b54332f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -53,7 +53,7 @@
         "eslint-config-prettier": "^8.5.0",
         "html-webpack-plugin": "^5.5.0",
         "jest": "^28.1.1",
-        "prettier": "^2.7.1",
+        "prettier": "^3.3.3",
         "rimraf": "^3.0.2",
         "ts-node-dev": "^2.0.0",
         "typescript": "^4.7.3",
@@ -9271,15 +9271,15 @@
       }
     },
     "node_modules/prettier": {
-      "version": "2.8.4",
-      "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.8.4.tgz",
-      "integrity": "sha512-vIS4Rlc2FNh0BySk3Wkd6xmwxB0FpOndW5fisM5H8hsZSxU2VWVB5CWIkIjWvrHjIhxk2g3bfMKM87zNTrZddw==",
+      "version": "3.3.3",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-3.3.3.tgz",
+      "integrity": "sha512-i2tDNA0O5IrMO757lfrdQZCc2jPNDVntV0m/+4whiDfWaTKfMNgR7Qz0NAeGz/nRqF4m5/6CLzbP4/liHt12Ew==",
       "dev": true,
       "bin": {
-        "prettier": "bin-prettier.js"
+        "prettier": "bin/prettier.cjs"
       },
       "engines": {
-        "node": ">=10.13.0"
+        "node": ">=14"
       },
       "funding": {
         "url": "https://github.com/prettier/prettier?sponsor=1"
@@ -17907,9 +17907,9 @@
       "dev": true
     },
     "prettier": {
-      "version": "2.8.4",
-      "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.8.4.tgz",
-      "integrity": "sha512-vIS4Rlc2FNh0BySk3Wkd6xmwxB0FpOndW5fisM5H8hsZSxU2VWVB5CWIkIjWvrHjIhxk2g3bfMKM87zNTrZddw==",
+      "version": "3.3.3",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-3.3.3.tgz",
+      "integrity": "sha512-i2tDNA0O5IrMO757lfrdQZCc2jPNDVntV0m/+4whiDfWaTKfMNgR7Qz0NAeGz/nRqF4m5/6CLzbP4/liHt12Ew==",
       "dev": true
     },
     "pretty-error": {
diff --git a/package.json b/package.json
index c505208..fa79773 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,8 @@
   ],
   "scripts": {
     "dev": "ts-node-dev --project tsconfig-backend.json backend/dev-cli.ts",
+    "fix": "prettier --write .",
+    "check": "prettier --check .",
     "cli": "node dist/backend/cli.js",
     "test": "jest",
     "typecheck": "tsc --noEmit",
@@ -60,7 +62,7 @@
     "eslint-config-prettier": "^8.5.0",
     "html-webpack-plugin": "^5.5.0",
     "jest": "^28.1.1",
-    "prettier": "^2.7.1",
+    "prettier": "^3.3.3",
     "rimraf": "^3.0.2",
     "ts-node-dev": "^2.0.0",
     "typescript": "^4.7.3",
diff --git a/sim/create.ts b/sim/create.ts
index 1f65692..a48b9cf 100644
--- a/sim/create.ts
+++ b/sim/create.ts
@@ -44,7 +44,7 @@ type Log = (...args: any[]) => void;
 
 export function createWebXdc(
   transport: Transport,
-  log: Log = () => {}
+  log: Log = () => {},
 ): WebXdc {
   let resolveUpdateListenerPromise: (() => void) | null = null;
 
@@ -72,7 +72,7 @@ export function createWebXdc(
           transport.setInfo(message.info);
         } else if (isDeleteMessage(message)) {
           log("delete");
-          window.top?.close()
+          window.top?.close();
         }
       });
       transport.onConnect(() => {
@@ -85,109 +85,111 @@ export function createWebXdc(
       return promise;
     },
     sendToChat: async (content) => {
-        if (!content.file && !content.text) {
-            alert("🚨 Error: either file or text need to be set. (or both)");
-            return Promise.reject(
-                "Error from sendToChat: either file or text need to be set"
-            );
-        }
-
-        /** @type {(file: Blob) => Promise<string>} */
-        const blob_to_base64 = (file) => {
-            const data_start = ";base64,";
-            return new Promise((resolve, reject) => {
-                const reader = new FileReader();
-                reader.readAsDataURL(file);
-                reader.onload = () => {
-                    /** @type {string} */
-                    //@ts-ignore
-                    let data = reader.result;
-                    resolve(
-                        data.slice(data.indexOf(data_start) + data_start.length)
-                    );
-                };
-                reader.onerror = () => reject(reader.error);
-            });
-        };
+      if (!content.file && !content.text) {
+        alert("🚨 Error: either file or text need to be set. (or both)");
+        return Promise.reject(
+          "Error from sendToChat: either file or text need to be set",
+        );
+      }
+
+      /** @type {(file: Blob) => Promise<string>} */
+      const blob_to_base64 = (file) => {
+        const data_start = ";base64,";
+        return new Promise((resolve, reject) => {
+          const reader = new FileReader();
+          reader.readAsDataURL(file);
+          reader.onload = () => {
+            /** @type {string} */
+            //@ts-ignore
+            let data = reader.result;
+            resolve(data.slice(data.indexOf(data_start) + data_start.length));
+          };
+          reader.onerror = () => reject(reader.error);
+        });
+      };
 
-        let base64Content;
-        if (content.file) {
-            if (!content.file.name) {
-                return Promise.reject("file name is missing");
-            }
-            if (
-                Object.keys(content.file).filter((key) =>
-                    ["blob", "base64", "plainText"].includes(key)
-                                                ).length > 1
-            ) {
-                return Promise.reject(
-                    "you can only set one of `blob`, `base64` or `plainText`, not multiple ones"
-                );
-            }
-
-            // @ts-ignore - needed because typescript imagines that blob would not exist
-            if (content.file.blob instanceof Blob) {
-                // @ts-ignore - needed because typescript imagines that blob would not exist
-                base64Content = await blob_to_base64(content.file.blob);
-                // @ts-ignore - needed because typescript imagines that base64 would not exist
-            } else if (typeof content.file.base64 === "string") {
-                // @ts-ignore - needed because typescript imagines that base64 would not exist
-                base64Content = content.file.base64;
-                // @ts-ignore - needed because typescript imagines that plainText would not exist
-            } else if (typeof content.file.plainText === "string") {
-                base64Content = await blob_to_base64(
-                    // @ts-ignore - needed because typescript imagines that plainText would not exist
-                    new Blob([content.file.plainText])
-                );
-            } else {
-                return Promise.reject(
-                    "data is not set or wrong format, set one of `blob`, `base64` or `plainText`, see webxdc documentation for sendToChat"
-                );
-            }
+      let base64Content;
+      if (content.file) {
+        if (!content.file.name) {
+          return Promise.reject("file name is missing");
+        }
+        if (
+          Object.keys(content.file).filter((key) =>
+            ["blob", "base64", "plainText"].includes(key),
+          ).length > 1
+        ) {
+          return Promise.reject(
+            "you can only set one of `blob`, `base64` or `plainText`, not multiple ones",
+          );
         }
-        const msg = `The app would now close and the user would select a chat to send this message:\nText: ${
-content.text ? `"${content.text}"` : "No Text"
-}\nFile: ${
-content.file ? `${content.file.name} - ${base64Content.length} bytes` : "No File"
-}`;
-        if (content.file) {
-            const confirmed = confirm(msg + '\n\nDownload the file in the browser instead?');
-            if (confirmed) {
-                var element = document.createElement("a");
-                element.setAttribute(
-                    "href",
-                    "data:application/octet-stream;base64," + base64Content
-                );
-                element.setAttribute("download", content.file.name);
-                document.body.appendChild(element);
-                element.click();
-                document.body.removeChild(element);
-            }
+
+        // @ts-ignore - needed because typescript imagines that blob would not exist
+        if (content.file.blob instanceof Blob) {
+          // @ts-ignore - needed because typescript imagines that blob would not exist
+          base64Content = await blob_to_base64(content.file.blob);
+          // @ts-ignore - needed because typescript imagines that base64 would not exist
+        } else if (typeof content.file.base64 === "string") {
+          // @ts-ignore - needed because typescript imagines that base64 would not exist
+          base64Content = content.file.base64;
+          // @ts-ignore - needed because typescript imagines that plainText would not exist
+        } else if (typeof content.file.plainText === "string") {
+          base64Content = await blob_to_base64(
+            // @ts-ignore - needed because typescript imagines that plainText would not exist
+            new Blob([content.file.plainText]),
+          );
         } else {
-            alert(msg);
+          return Promise.reject(
+            "data is not set or wrong format, set one of `blob`, `base64` or `plainText`, see webxdc documentation for sendToChat",
+          );
         }
+      }
+      const msg = `The app would now close and the user would select a chat to send this message:\nText: ${
+        content.text ? `"${content.text}"` : "No Text"
+      }\nFile: ${
+        content.file
+          ? `${content.file.name} - ${base64Content.length} bytes`
+          : "No File"
+      }`;
+      if (content.file) {
+        const confirmed = confirm(
+          msg + "\n\nDownload the file in the browser instead?",
+        );
+        if (confirmed) {
+          var element = document.createElement("a");
+          element.setAttribute(
+            "href",
+            "data:application/octet-stream;base64," + base64Content,
+          );
+          element.setAttribute("download", content.file.name);
+          document.body.appendChild(element);
+          element.click();
+          document.body.removeChild(element);
+        }
+      } else {
+        alert(msg);
+      }
     },
     importFiles: (filters) => {
-        var element = document.createElement("input");
-        element.type = "file";
-        element.accept = [
-            ...(filters.extensions || []),
-            ...(filters.mimeTypes || []),
-        ].join(",");
-        element.multiple = filters.multiple || false;
-        const promise = new Promise((resolve, _reject) => {
-            element.onchange = (_ev) => {
-                console.log("element.files", element.files);
-                const files = Array.from(element.files || []);;
-                document.body.removeChild(element);
-                resolve(files);
-            };
-        });
-        element.style.display = "none";
-        document.body.appendChild(element);
-        element.click();
-        console.log(element);
-        return promise;
+      var element = document.createElement("input");
+      element.type = "file";
+      element.accept = [
+        ...(filters.extensions || []),
+        ...(filters.mimeTypes || []),
+      ].join(",");
+      element.multiple = filters.multiple || false;
+      const promise = new Promise((resolve, _reject) => {
+        element.onchange = (_ev) => {
+          console.log("element.files", element.files);
+          const files = Array.from(element.files || []);
+          document.body.removeChild(element);
+          resolve(files);
+        };
+      });
+      element.style.display = "none";
+      document.body.appendChild(element);
+      element.click();
+      console.log(element);
+      return promise;
     },
     selfAddr: transport.address(),
     selfName: transport.name(),
diff --git a/sim/ui.ts b/sim/ui.ts
index 7f9846d..57dd94d 100644
--- a/sim/ui.ts
+++ b/sim/ui.ts
@@ -3,9 +3,9 @@ import { DevServerTransport } from "./webxdc";
 const consoleFunctionNames = ["debug", "log", "info", "warn", "error"] as const;
 
 function overwriteConsoleFunction(
-  functionName: typeof consoleFunctionNames[number],
+  functionName: (typeof consoleFunctionNames)[number],
   deviceIdentifier: string,
-  logStyle: string
+  logStyle: string,
 ) {
   const original = console[functionName];
   const replacement = original.bind(null, `%c${deviceIdentifier}`, logStyle);
@@ -15,7 +15,7 @@ function overwriteConsoleFunction(
 
 export async function overwriteConsole(
   deviceIdentifier: string,
-  transport: DevServerTransport
+  transport: DevServerTransport,
 ) {
   const info = await transport.getInfo();
   const logStyle = `color:white;font-weight:bold;border-radius:4px;padding:2px;background: ${info.color}`;
@@ -26,7 +26,7 @@ export async function overwriteConsole(
 
 export async function alterUi(
   instanceName: string,
-  transport: DevServerTransport
+  transport: DevServerTransport,
 ): Promise<void> {
   const info = await transport.getInfo();
   let title = document.getElementsByTagName("title")[0];
diff --git a/sim/webxdc.test.ts b/sim/webxdc.test.ts
index 6d7170d..7a198d6 100644
--- a/sim/webxdc.test.ts
+++ b/sim/webxdc.test.ts
@@ -19,7 +19,7 @@ class FakeTransport implements Transport {
     public client: WebXdcMulti,
     address: string,
     name: string,
-    public onClear: () => void
+    public onClear: () => void,
   ) {
     this._address = address;
     this._name = name;
@@ -46,7 +46,7 @@ class FakeTransport implements Transport {
             this.messageCallback({ type: "clear" });
           }
           return true;
-        }
+        },
       );
     } else if (data.type === "requestInfo") {
       if (this.messageCallback != null) {
diff --git a/sim/webxdc.ts b/sim/webxdc.ts
index c951f02..1f152df 100644
--- a/sim/webxdc.ts
+++ b/sim/webxdc.ts
@@ -65,16 +65,18 @@ export class DevServerTransport implements Transport {
     window.sessionStorage.clear();
 
     const databases = await window.indexedDB.databases();
-    
-    await Promise.all(databases.map(result => {
-      return new Promise((resolve, reject) => {
-        const name = result?.name;
-        console.log(`Deleting indexedDB database: ${name}`);
-        const request = window.indexedDB.deleteDatabase(name);
-        request.onsuccess = ev => resolve(ev);
-        request.onerror = ev => reject(ev);
-      });
-    }));
+
+    await Promise.all(
+      databases.map((result) => {
+        return new Promise((resolve, reject) => {
+          const name = result?.name;
+          console.log(`Deleting indexedDB database: ${name}`);
+          const request = window.indexedDB.deleteDatabase(name);
+          request.onsuccess = (ev) => resolve(ev);
+          request.onerror = (ev) => reject(ev);
+        });
+      }),
+    );
 
     // we want to reload the window otherwise we won't take the
     // cleared localstorage into account
diff --git a/types/webxdc.ts b/types/webxdc.ts
index bf0af0b..72de897 100644
--- a/types/webxdc.ts
+++ b/types/webxdc.ts
@@ -59,20 +59,20 @@ export type SendUpdate<T> = (update: Update<T>, descr: string) => void;
 export type SendToChat = (message: SendOptions) => Promise<void>;
 
 export type ImportFiles = (filter: {
-    /**
-     * mimetypes as in https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/accept#unique_file_type_specifiers
-     */
-    mimeTypes?: string[];
-    /** only show files with these extensions.
-     * All extensions need to start with a dot and have the format `.ext`. */
-    extensions?: string[];
-    /** false by default, whether to allow multiple files to be selected */
-    multiple?: boolean;
-  }) => Promise<File[]>;
+  /**
+   * mimetypes as in https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/accept#unique_file_type_specifiers
+   */
+  mimeTypes?: string[];
+  /** only show files with these extensions.
+   * All extensions need to start with a dot and have the format `.ext`. */
+  extensions?: string[];
+  /** false by default, whether to allow multiple files to be selected */
+  multiple?: boolean;
+}) => Promise<File[]>;
 
 export type SetUpdateListener<T> = (
   listener: UpdateListener<T>,
-  serial: number
+  serial: number,
 ) => Promise<void>;
 
 export type WebXdc<T = JsonValue> = {