diff --git a/package.json b/package.json
index 1fa3ec89..7536f71a 100644
--- a/package.json
+++ b/package.json
@@ -99,7 +99,7 @@
     "build:default": "GENERATE_SOURCEMAP=false CI=false react-scripts build",
     "prebuild": "node -e \"let pkg=require('./package.json'); pkg.homepage='/'; require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2));\"",
     "postbuild": "run-script-os",
-    "postbuild:win32": "node -e \"let pkg=require('./package.json'); pkg.homepage='.'; require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2));\" && del /q build\\app && rm -rf build\\preload.js && rm -rf build\\renderer.js && rm -rf build\\electron.js",
+    "postbuild:win32": "node -e \"let pkg=require('./package.json'); pkg.homepage='.'; require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2));\" && del /q build\\app && del /q build\\preload.js && del /q build\\renderer.js && del /q build\\electron.js",
     "postbuild:default": "node -e \"let pkg=require('./package.json'); pkg.homepage='.'; require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2));\" && rm -rf build/app && rm -rf build/preload.js && rm -rf build/renderer.js && rm -rf build/electron.js",
     "buildhass": "GENERATE_SOURCEMAP=false CI=false react-scripts build",
     "prebuildhass": "node -e \"let pkg=require('./package.json'); pkg.homepage='./'; require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2));\"",
@@ -195,6 +195,7 @@
     "@types/eslint__js": "^8.42.3",
     "@types/node": "^22.10.2",
     "@types/prop-types": "^15.7.11",
+    "@types/qrcode": "^1.5.5",
     "@types/react": "^18.3.12",
     "@types/react-beautiful-dnd": "^13.1.8",
     "@types/react-dom": "^18.2.19",
@@ -287,4 +288,4 @@
       ]
     }
   }
-}
+}
\ No newline at end of file
diff --git a/src/app/app/handlers.js b/src/app/app/handlers.mts
similarity index 70%
rename from src/app/app/handlers.js
rename to src/app/app/handlers.mts
index 33e6c9a3..03f882ea 100644
--- a/src/app/app/handlers.js
+++ b/src/app/app/handlers.mts
@@ -1,34 +1,47 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 import { app, shell, BrowserWindow, nativeTheme } from 'electron'
 import path from 'path'
 import { generateMfaQr, handleVerifyOTP } from './otp.js'
-import { startInstance, stopInstance, sendStatus } from './instances.js'
+import {
+  startInstance,
+  stopInstance,
+  sendStatus,
+  Subprocesses,
+  IPlatform
+} from './instances.mjs'
 import coreParams from './utils/coreParams.mjs'
 import defaultCoreParams from './utils/defaultCoreParams.mjs'
 import store from './utils/store.mjs'
 import isCC from './utils/isCC.mjs'
 
-export const handlers = async (wind, subprocesses, event, parameters) => {
+export const handlers = async (
+  wind: BrowserWindow,
+  subprocesses: Subprocesses,
+  event: any,
+  parameters: any
+) => {
   console.log('ALL PARAMS', parameters)
 
   try {
     switch (parameters.command) {
       case 'close-others':
-        BrowserWindow.getAllWindows().forEach(win => {
+        BrowserWindow.getAllWindows().forEach((win) => {
           if (win !== wind) {
-            win.close();
+            win.close()
           }
-        });
-        break;
-      case 'get-all-windows':
+        })
+        break
+      case 'get-all-windows': {
         const allWIndows = BrowserWindow.getAllWindows()
         console.log('allWIndows', allWIndows)
         wind.webContents.send('fromMain', ['all-windows', allWIndows])
         break
+      }
       case 'verify_otp':
-        handleVerifyOTP(wind, event, parameters)
+        handleVerifyOTP(wind, parameters)
         break
       case 'generate-mfa-qr':
-        generateMfaQr(event, parameters)
+        generateMfaQr(wind)
         break
       case 'get-platform':
         wind.webContents.send('fromMain', ['platform', process.platform])
@@ -39,7 +52,7 @@ export const handlers = async (wind, subprocesses, event, parameters) => {
             'coreParams',
             coreParams[process.platform]
           ])
-          sendStatus(wind, subprocesses)
+          sendStatus(wind, subprocesses, false, parameters.instance)
         }
         break
       case 'start-core':
@@ -81,12 +94,12 @@ export const handlers = async (wind, subprocesses, event, parameters) => {
       case 'delete-core-params':
         if (isCC) {
           store.set('coreParams', defaultCoreParams)
-          coreParams.darwin = defaultCoreParams['darwin']
-          coreParams.win32 = defaultCoreParams['win32']
-          coreParams.linux = defaultCoreParams['linux']
+          coreParams.darwin = defaultCoreParams.darwin
+          coreParams.win32 = defaultCoreParams.win32
+          coreParams.linux = defaultCoreParams.linux
           wind.webContents.send('fromMain', [
             'coreParams',
-            defaultCoreParams[process.platform]
+            defaultCoreParams[process.platform as IPlatform]
           ])
           app.relaunch()
           app.exit()
@@ -97,20 +110,35 @@ export const handlers = async (wind, subprocesses, event, parameters) => {
 
         if (parameters.instance && parameters.instance !== 'instance1') {
           shell.showItemInFolder(
-            path.join(app.getPath("userData"), '.ledfx-cc', parameters.instance, 'config.json')
+            path.join(
+              app.getPath('userData'),
+              '.ledfx-cc',
+              parameters.instance,
+              'config.json'
+            )
           )
           shell.showItemInFolder(
-            path.join(app.getPath("appData"), '.ledfx-cc', parameters.instance, 'config.json')
+            path.join(
+              app.getPath('appData'),
+              '.ledfx-cc',
+              parameters.instance,
+              'config.json'
+            )
           )
           shell.showItemInFolder(
-            path.join(app.getPath("home"), '.ledfx-cc', parameters.instance, 'config.json')
+            path.join(
+              app.getPath('home'),
+              '.ledfx-cc',
+              parameters.instance,
+              'config.json'
+            )
           )
         } else {
           shell.showItemInFolder(
-            path.join(app.getPath("userData"), '.ledfx', 'config.json')
+            path.join(app.getPath('userData'), '.ledfx', 'config.json')
           )
           shell.showItemInFolder(
-            path.join(app.getPath("appData"), '.ledfx', 'config.json')
+            path.join(app.getPath('appData'), '.ledfx', 'config.json')
           )
           shell.showItemInFolder(
             path.join(app.getPath('home'), '.ledfx', 'config.json')
@@ -137,4 +165,3 @@ export const handlers = async (wind, subprocesses, event, parameters) => {
     console.error(`Error handling command "${parameters.command}": ${error}`)
   }
 }
-
diff --git a/src/app/app/instances.js b/src/app/app/instances.mts
similarity index 55%
rename from src/app/app/instances.js
rename to src/app/app/instances.mts
index 866fb3e3..145aec16 100644
--- a/src/app/app/instances.js
+++ b/src/app/app/instances.mts
@@ -1,22 +1,49 @@
 import { BrowserWindow } from 'electron'
 import coreParams from './utils/coreParams.mjs'
 import startCore from './utils/startCore.mjs'
+import { ChildProcessWithoutNullStreams } from 'child_process'
 
-export const poll = async (wind, subprocesses, name, p) => {
+export interface Subprocess extends ChildProcessWithoutNullStreams {
+  running?: boolean
+}
+
+export interface Subprocesses {
+  [key: string]: Subprocess
+}
+
+export type IPlatform = 'darwin' | 'win32' | 'linux'
+
+export function kills(subprocess: Subprocess | null): void {
+  if (subprocess !== null) {
+    subprocess.kill('SIGINT')
+  }
+}
+
+export const poll = async (
+  wind: BrowserWindow,
+  subprocesses: Subprocesses,
+  name: string,
+  p: string
+) => {
   console.log('Polling core', name, 'on port', p)
   if (!p) return
   try {
     const response = await fetch(`http://127.0.0.1:${p}/api/info`)
-    const data = await response.json()
+    await response.json()
     sendStatus(wind, subprocesses, true, name)
     console.log('Polling core succeeded')
-  } catch (err) {
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  } catch (e) {
     console.log('Polling core ...')
     setTimeout(() => poll(wind, subprocesses, name, p), 1000)
   }
 }
 
-export function stopInstance(wind, name, subprocesses) {
+export function stopInstance(
+  wind: BrowserWindow,
+  name: string,
+  subprocesses: Subprocesses
+) {
   if (subprocesses[name]) {
     subprocesses[name].running = false
     sendStatus(wind, subprocesses, false, name)
@@ -24,14 +51,23 @@ export function stopInstance(wind, name, subprocesses) {
   }
 }
 
-export function startInstance(wind, name, subprocesses, port) {
+export function startInstance(
+  wind: BrowserWindow,
+  name: string,
+  subprocesses: Subprocesses,
+  port: string = '8889'
+) {
   try {
-    let subpy = startCore(wind, process.platform, name, port)
+    const subpy = startCore(wind, process.platform as IPlatform, name, port)
     if (subpy !== null) {
       subprocesses[name] = subpy
       subprocesses[name].running = true
       sendStatus(wind, subprocesses, false, name)
       poll(wind, subprocesses, name, port)
+      if (!subpy) {
+        console.error('Error starting subprocess')
+        return
+      }
       subpy.on('exit', () => {
         if (subprocesses[name]) {
           subprocesses[name].running = false
@@ -39,13 +75,13 @@ export function startInstance(wind, name, subprocesses, port) {
         if (wind && wind.webContents && !wind.isDestroyed() && subprocesses) {
           // `subprocesses` is defined, proceed with calling `sendStatus`
           try {
-            sendStatus(wind, subprocesses, false, name);
+            sendStatus(wind, subprocesses, false, name)
           } catch (error) {
-            console.error(error);
+            console.error(error)
           }
         } else {
           // `subprocesses` is not defined, handle this case as needed
-          console.error('subprocesses is not defined');
+          console.error('subprocesses is not defined')
         }
       })
       subpy.on('error', () => {
@@ -60,28 +96,33 @@ export function startInstance(wind, name, subprocesses, port) {
   }
 }
 
-export function sendStatus(wind, subprocesses, connected = false, n) {
-  let status = {}
-  let platformParams = coreParams[process.platform]
+export function sendStatus(
+  wind: BrowserWindow,
+  subprocesses: Subprocesses,
+  connected = false,
+  n: string
+) {
+  const status: { [key: string]: string } = {}
+  const platformParams = coreParams[process.platform]
   // Check if `wind` is an instance of `BrowserWindow`
   if (!(wind instanceof BrowserWindow)) {
-    console.error('wind is not an instance of BrowserWindow');
-    return;
+    console.error('wind is not an instance of BrowserWindow')
+    return
   }
 
   // Check if `subprocesses` is defined
   if (!subprocesses) {
-    console.error('subprocesses is not defined');
-    return;
+    console.error('subprocesses is not defined')
+    return
   }
 
   // Check if `n` is defined
   if (!n) {
-    console.error('n is not defined');
-    return;
+    console.error('n is not defined')
+    return
   }
 
-  for (let name in platformParams) {
+  for (const name in platformParams) {
     if (subprocesses && subprocesses[name]) {
       if (name === n) {
         status[name] = connected
@@ -96,17 +137,17 @@ export function sendStatus(wind, subprocesses, connected = false, n) {
       status[name] = 'stopped'
     }
   }
-  if (wind && wind.webContents  && !wind.isDestroyed() && status) wind.webContents.send('fromMain', ['status', status])
-}
-
-export function kills(subprocess) {
-  if (subprocess !== null) {
-    subprocess.kill('SIGINT')
-  }
+  if (wind && wind.webContents && !wind.isDestroyed() && status)
+    wind.webContents.send('fromMain', ['status', status])
 }
 
-export function closeAllSubs(wind, subpy, subprocesses) {
-  if (wind && wind.webContents && !wind.isDestroyed()) wind.webContents.send('fromMain', 'shutdown')
+export function closeAllSubs(
+  wind: BrowserWindow,
+  subpy: Subprocess,
+  subprocesses: Subprocesses
+) {
+  if (wind && wind.webContents && !wind.isDestroyed())
+    wind.webContents.send('fromMain', 'shutdown')
   if (subpy !== null) kills(subpy)
   if (subprocesses && Object.keys(subprocesses).length > 0) {
     Object.values(subprocesses).forEach((sub) => {
@@ -114,4 +155,3 @@ export function closeAllSubs(wind, subpy, subprocesses) {
     })
   }
 }
-
diff --git a/src/app/app/media.js b/src/app/app/media.ts
similarity index 58%
rename from src/app/app/media.js
rename to src/app/app/media.ts
index 9df3a7c4..55bf478f 100644
--- a/src/app/app/media.js
+++ b/src/app/app/media.ts
@@ -1,9 +1,20 @@
 const { execFile } = require('child_process');
 const path = require('path');
+import { fileURLToPath } from 'node:url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
 
 const exePath = path.join(__dirname, 'path_to_dist_folder', 'media.exe');
 
-execFile(exePath, (error, stdout, stderr) => {
+interface MediaInfo {
+    title: string;
+    artist: string;
+    album: string;
+    error?: string;
+}
+
+execFile(exePath, (error: Error | null, stdout: string, stderr: string) => {
     if (error) {
         console.error(`Error: ${error.message}`);
         return;
@@ -13,7 +24,7 @@ execFile(exePath, (error, stdout, stderr) => {
         return;
     }
     try {
-        const mediaInfo = JSON.parse(stdout);
+        const mediaInfo: MediaInfo = JSON.parse(stdout);
         if (mediaInfo.error) {
             console.log(mediaInfo.error);
         } else {
@@ -22,6 +33,6 @@ execFile(exePath, (error, stdout, stderr) => {
             console.log(`Album: ${mediaInfo.album}`);
         }
     } catch (parseError) {
-        console.error(`JSON Parse Error: ${parseError.message}`);
+        console.error(`JSON Parse Error: ${(parseError as Error).message}`);
     }
 });
\ No newline at end of file
diff --git a/src/app/app/otp.js b/src/app/app/otp.ts
similarity index 85%
rename from src/app/app/otp.js
rename to src/app/app/otp.ts
index 94daad6c..cf0a2fc0 100644
--- a/src/app/app/otp.js
+++ b/src/app/app/otp.ts
@@ -3,9 +3,10 @@ import qrcode from 'qrcode'
 import base32Decode from 'base32-decode'
 import base32Encode from 'base32-encode'
 import store from './utils/store.mjs'
+import { BrowserWindow } from 'electron'
 
 
-export function generateHOTP(secret, counter) {
+export function generateHOTP(secret: string, counter: number) {
   const decodedSecret = base32Decode(secret, 'RFC4648');
 
   const buffer = Buffer.alloc(8);
@@ -31,12 +32,12 @@ export function generateHOTP(secret, counter) {
   return `${code % 10 ** 6}`.padStart(6, '0');
 }
 
-export function generateTOTP(secret, window = 0) {
+export function generateTOTP(secret: string, window = 0) {
   const counter = Math.floor(Date.now() / 30000);
   return generateHOTP(secret, counter + window);
 }
 
-export function verifyTOTP(token, secret, window = 1) {
+export function verifyTOTP(token: string, secret: string, window = 1) {
   for (let errorWindow = -window; errorWindow <= +window; errorWindow++) {
     const totp = generateTOTP(secret, errorWindow);
     if (token === totp) {
@@ -46,7 +47,7 @@ export function verifyTOTP(token, secret, window = 1) {
   return false;
 }
 
-export function generateMfaQr(event, parameters) {
+export function generateMfaQr(wind: BrowserWindow) {
   const user = store.get('user') || {
     username: 'FreeUser',
     mfaEnabled: false,
@@ -73,11 +74,11 @@ export function generateMfaQr(event, parameters) {
 
   qrcode.toDataURL(configUri, {
     color: { dark: '#333333FF', light: '#00000000' },
-  }).then((png=>wind.webContents.send('fromMain', ['mfa-qr-code', png])));
+  }).then(((png: any) => wind.webContents.send('fromMain', ['mfa-qr-code', png])));
 
   return;
 }
-export function handleVerifyOTP(wind, event, parameters) {
+export function handleVerifyOTP(wind: BrowserWindow, parameters: any) {
   const user = store.get('user') || {
     username: 'FreeUser',
     mfaEnabled: false,
diff --git a/src/app/app/protocol.js b/src/app/app/protocol.js
deleted file mode 100644
index 81abaad1..00000000
--- a/src/app/app/protocol.js
+++ /dev/null
@@ -1,48 +0,0 @@
-import { app } from 'electron'
-import path from 'path'
-
-export const setupProtocol = () => {
-  (async () => {    
-    const isSquirrelStartup = await import('electron-squirrel-startup');
-    if (isSquirrelStartup.default) {
-      app.quit()
-    }
-  })()
-
-  if (process.defaultApp) {
-    if (process.argv.length >= 2) {
-      app.setAsDefaultProtocolClient('ledfx', process.execPath, [
-        path.resolve(process.argv[1])
-      ])
-    }
-  } else {
-    app.setAsDefaultProtocolClient('ledfx')
-  }
-}
-
-export const handleProtocol = (getWind, gotTheLock, ready) => {
-  if (process.platform === 'win32') {
-    if (!gotTheLock) {
-      app.quit()
-    } else {
-      app.on('second-instance', (event, commandLine, workingDirectory) => {
-        const wind = getWind()
-        console.log(commandLine, wind)
-        if (wind) {
-          if (wind.isMinimized()) wind.restore()
-          wind.webContents.send('fromMain', [
-            'protocol',
-            JSON.stringify({ event, commandLine, workingDirectory })
-          ])
-          wind.focus()
-        }
-      })
-      ready()
-      app.on('open-url', (event, url) => console.log(event, url))
-    }
-  } else {
-    ready()
-    app.on('open-url', (event, url) => console.log(event, url))
-  }
-}
-
diff --git a/src/app/app/protocol.mts b/src/app/app/protocol.mts
new file mode 100644
index 00000000..7317a5b5
--- /dev/null
+++ b/src/app/app/protocol.mts
@@ -0,0 +1,62 @@
+import { app } from 'electron'
+import path from 'path'
+
+export const setupProtocol = () => {
+  ;(async () => {
+    const isSquirrelStartup = await import('electron-squirrel-startup')
+    if (isSquirrelStartup.default) {
+      app.quit()
+    }
+  })()
+
+  if (process.defaultApp) {
+    if (process.argv.length >= 2) {
+      app.setAsDefaultProtocolClient('ledfx', process.execPath, [
+        path.resolve(process.argv[1])
+      ])
+    }
+  } else {
+    app.setAsDefaultProtocolClient('ledfx')
+  }
+}
+
+export const handleProtocol = (
+  getWind: () => Electron.BrowserWindow | null,
+  gotTheLock: boolean,
+  ready: () => void
+) => {
+  if (process.platform === 'win32') {
+    if (!gotTheLock) {
+      app.quit()
+    } else {
+      app.on(
+        'second-instance',
+        (
+          event: Electron.Event,
+          commandLine: string[],
+          workingDirectory: string
+        ) => {
+          const wind = getWind()
+          console.log(commandLine, wind)
+          if (wind) {
+            if (wind.isMinimized()) wind.restore()
+            wind.webContents.send('fromMain', [
+              'protocol',
+              JSON.stringify({ event, commandLine, workingDirectory })
+            ])
+            wind.focus()
+          }
+        }
+      )
+      ready()
+      app.on('open-url', (event: Electron.Event, url: string) =>
+        console.log(event, url)
+      )
+    }
+  } else {
+    ready()
+    app.on('open-url', (event: Electron.Event, url: string) =>
+      console.log(event, url)
+    )
+  }
+}
diff --git a/src/app/app/toast.js b/src/app/app/toast.ts
similarity index 93%
rename from src/app/app/toast.js
rename to src/app/app/toast.ts
index 880a21ff..1faae695 100644
--- a/src/app/app/toast.js
+++ b/src/app/app/toast.ts
@@ -2,6 +2,7 @@ import fs from 'fs'
 import path from 'path'
 import { Notification } from 'electron'
 import { fileURLToPath } from 'node:url'
+import isDev from 'electron-is-dev';
 
 const __filename = fileURLToPath(import.meta.url)
 const __dirname = path.dirname(__filename)
@@ -11,7 +12,7 @@ const NOTIFICATION_BODY = 'Testing Notification from the Main process';
 function getConfig() {
   const configPath = path.join(path.dirname(__dirname), isDev ? '../' : '../../', 'frontend_config.json')
   const configData = fs.readFileSync(configPath);
-  return JSON.parse(configData);
+  return JSON.parse(configData.toString());
 }
 
 export function showNotification(title = NOTIFICATION_TITLE, body = NOTIFICATION_BODY) {
diff --git a/src/app/app/utils/coreFile.mjs b/src/app/app/utils/coreFile.mts
similarity index 100%
rename from src/app/app/utils/coreFile.mjs
rename to src/app/app/utils/coreFile.mts
diff --git a/src/app/app/utils/coreParams.mjs b/src/app/app/utils/coreParams.mts
similarity index 100%
rename from src/app/app/utils/coreParams.mjs
rename to src/app/app/utils/coreParams.mts
diff --git a/src/app/app/utils/corePath.mjs b/src/app/app/utils/corePath.mts
similarity index 90%
rename from src/app/app/utils/corePath.mjs
rename to src/app/app/utils/corePath.mts
index ba3f65f9..54034668 100644
--- a/src/app/app/utils/corePath.mjs
+++ b/src/app/app/utils/corePath.mts
@@ -5,7 +5,7 @@ import { fileURLToPath } from 'url'
 const __filename = fileURLToPath(import.meta.url)
 const __dirname = path.dirname(__filename)
 
-const corePath = (file) =>
+const corePath = (file: string) =>
   path.join(
     path.dirname(__dirname),
     isDev ? '../extraResources' : '../../extraResources',
diff --git a/src/app/app/utils/defaultCoreParams.mjs b/src/app/app/utils/defaultCoreParams.mts
similarity index 100%
rename from src/app/app/utils/defaultCoreParams.mjs
rename to src/app/app/utils/defaultCoreParams.mts
diff --git a/src/app/app/utils/isCC.mjs b/src/app/app/utils/isCC.mts
similarity index 52%
rename from src/app/app/utils/isCC.mjs
rename to src/app/app/utils/isCC.mts
index a84d4416..fda121a2 100644
--- a/src/app/app/utils/isCC.mjs
+++ b/src/app/app/utils/isCC.mts
@@ -2,6 +2,8 @@ import fs from 'fs'
 import corePath from './corePath.mjs'
 import coreFile from './coreFile.mjs'
 
-export const isCC = fs.existsSync(corePath(coreFile[process.platform]))
+export const isCC = fs.existsSync(
+  corePath(coreFile[process.platform as 'darwin' | 'linux' | 'win32'])
+)
 
 export default isCC
diff --git a/src/app/app/utils/runCore.mjs b/src/app/app/utils/runCore.mts
similarity index 68%
rename from src/app/app/utils/runCore.mjs
rename to src/app/app/utils/runCore.mts
index 40c03284..9e6cd824 100644
--- a/src/app/app/utils/runCore.mjs
+++ b/src/app/app/utils/runCore.mts
@@ -1,7 +1,8 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 import * as cp from 'child_process'
 import corePath from './corePath.mjs'
 
-const runCore = (file, options) =>
+const runCore = (file: string, options: any) =>
   cp.spawn(`${corePath(file)}`, options).on('error', (err) => {
     console.error(`Failed to start subprocess. ${err}`)
   })
diff --git a/src/app/app/utils/startCore.mjs b/src/app/app/utils/startCore.mts
similarity index 88%
rename from src/app/app/utils/startCore.mjs
rename to src/app/app/utils/startCore.mts
index 11ab6606..7ff7fcc1 100644
--- a/src/app/app/utils/startCore.mjs
+++ b/src/app/app/utils/startCore.mts
@@ -1,4 +1,4 @@
-import { app } from 'electron'
+import { app, BrowserWindow } from 'electron'
 import fs from 'fs'
 import path from 'path'
 import runCore from './runCore.mjs'
@@ -6,9 +6,15 @@ import corePath from './corePath.mjs'
 import coreFile from './coreFile.mjs'
 import coreParams from './coreParams.mjs'
 import store from './store.mjs'
+import { ChildProcessWithoutNullStreams } from 'child_process'
 
-function startCore(wind, platform, instance = 'instance1', port = '8889') {
-  let subpy
+function startCore(
+  wind: BrowserWindow,
+  platform: 'darwin' | 'linux' | 'win32',
+  instance = 'instance1',
+  port = '8889'
+) {
+  let subpy: ChildProcessWithoutNullStreams | null = null
 
   if (fs.existsSync(corePath(coreFile[platform]))) {
     if (coreParams[platform] && instance && coreParams[platform][instance]) {
diff --git a/src/app/app/utils/store.mjs b/src/app/app/utils/store.mjs
deleted file mode 100644
index 0ebf2af3..00000000
--- a/src/app/app/utils/store.mjs
+++ /dev/null
@@ -1,5 +0,0 @@
-import Store from 'electron-store'
-
-const store = new Store()
-
-export default store
diff --git a/src/app/app/utils/store.mts b/src/app/app/utils/store.mts
new file mode 100644
index 00000000..a5015e95
--- /dev/null
+++ b/src/app/app/utils/store.mts
@@ -0,0 +1,6 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import Store from 'electron-store'
+
+const store: any = new Store()
+
+export default store
diff --git a/src/app/app/utils/tray.mjs b/src/app/app/utils/tray.mts
similarity index 89%
rename from src/app/app/utils/tray.mjs
rename to src/app/app/utils/tray.mts
index 5e6fc32f..b21e29a5 100644
--- a/src/app/app/utils/tray.mjs
+++ b/src/app/app/utils/tray.mts
@@ -1,11 +1,15 @@
 import path from 'path'
-import { app, Menu, shell, Tray } from 'electron'
+import { app, BrowserWindow, Menu, shell, Tray } from 'electron'
 import isDev from 'electron-is-dev'
 import startCore from './startCore.mjs'
 import coreParams from './coreParams.mjs'
 // import { download } from 'electron-dl'
 
-export function createMenu(isCC, wind, thePath) {
+export function createMenu(
+  isCC: boolean,
+  wind: BrowserWindow,
+  thePath: string
+) {
   let contextMenu
 
   if (isCC) {
@@ -31,7 +35,12 @@ export function createMenu(isCC, wind, thePath) {
       { label: 'seperator', type: 'separator' },
       {
         label: 'Start core',
-        click: () => startCore(wind, process.platform, coreParams.instance)
+        click: () =>
+          startCore(
+            wind,
+            process.platform as 'darwin' | 'linux' | 'win32',
+            coreParams.instance
+          )
       },
       {
         label: 'Stop core',
@@ -91,7 +100,12 @@ export function createMenu(isCC, wind, thePath) {
   return contextMenu
 }
 
-export function createTray(isCC, wind, thePath, dir) {
+export function createTray(
+  isCC: boolean,
+  wind: BrowserWindow,
+  thePath: string,
+  dir: string
+) {
   const icon = path.join(dir, 'icon_16x16a.png')
   const tray = new Tray(icon)
 
diff --git a/src/app/app/utils/win.mjs b/src/app/app/utils/win.mts
similarity index 91%
rename from src/app/app/utils/win.mjs
rename to src/app/app/utils/win.mts
index 718d4b2a..65e7f643 100644
--- a/src/app/app/utils/win.mjs
+++ b/src/app/app/utils/win.mts
@@ -7,7 +7,8 @@ import { fileURLToPath } from 'node:url'
 const __filename = fileURLToPath(import.meta.url)
 const __dirname = path.dirname(__filename)
 
-function createWindow(win, args = {}) {
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function createWindow(win?: any, args = {}) {
   initialize()
   // Create the browser window.
   win = new BrowserWindow({
diff --git a/src/app/electron.ts b/src/app/electron.ts
index 1ac49f42..251b06b6 100644
--- a/src/app/electron.ts
+++ b/src/app/electron.ts
@@ -1,15 +1,15 @@
 import fs from 'fs';
 import path from 'path';
-import isCC from './app/utils/isCC.mjs';
 import isDev from 'electron-is-dev';
-import createWindow from './app/utils/win.mjs';
 import { app, nativeTheme, BrowserWindow, ipcMain, shell, session } from 'electron';
-import { createTray } from './app/utils/tray.mjs';
-import { startInstance, closeAllSubs } from './app/instances.js';
-import { handlers } from './app/handlers.js';
-import { setupProtocol, handleProtocol } from './app/protocol.js';
 import { EventEmitter } from 'events';
 import { fileURLToPath } from 'node:url';
+import isCC from './app/utils/isCC.mjs';
+import createWindow from './app/utils/win.mjs';
+import { handleProtocol, setupProtocol } from './app/protocol.mjs';
+import { closeAllSubs, startInstance } from './app/instances.mjs';
+import { createTray } from './app/utils/tray.mjs'
+import { handlers } from './app/handlers.mjs';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -63,10 +63,10 @@ const ready = () =>
     createTray(isCC, wind, thePath, __dirname)
 
     ipcMain.on('toMain', async (event, parameters) =>
-      handlers(wind, subprocesses, event, parameters)
+      wind && handlers(wind, subprocesses, event, parameters)
     )
     wind.on('close', () => {
-      closeAllSubs(wind, subpy, subprocesses)
+      wind && closeAllSubs(wind, subpy, subprocesses)
       wind = null;
     })
   })
@@ -74,11 +74,11 @@ const ready = () =>
 handleProtocol(() => wind, gotTheLock, ready)
 
 app.on('window-all-closed', () => {
-  closeAllSubs(wind, subpy, subprocesses)
+  wind && closeAllSubs(wind, subpy, subprocesses)
   app.quit()
 })
 
-app.on('before-quit', () => closeAllSubs(wind, subpy, subprocesses))
+app.on('before-quit', () => wind && closeAllSubs(wind, subpy, subprocesses))
 
 app.on(
   'activate',
diff --git a/src/electronsquirrelstartup.d..ts b/src/electronsquirrelstartup.d..ts
new file mode 100644
index 00000000..ea53c53e
--- /dev/null
+++ b/src/electronsquirrelstartup.d..ts
@@ -0,0 +1 @@
+declare module 'electron-squirrel-startup';
\ No newline at end of file
diff --git a/tsconfig.json b/tsconfig.json
index 47c2bc76..9a288031 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -15,7 +15,7 @@
     "isolatedModules": true,
     "noEmit": true,
     "jsx": "react-jsx",
-    "skipLibCheck": true
+    "skipLibCheck": true,
   },
   "include": ["src"]
 }