diff --git a/apps/stage-tamagotchi/src/main/index.ts b/apps/stage-tamagotchi/src/main/index.ts
index 2e09daa47..2fab89e75 100644
--- a/apps/stage-tamagotchi/src/main/index.ts
+++ b/apps/stage-tamagotchi/src/main/index.ts
@@ -19,7 +19,7 @@ import { openDebugger, setupDebugger } from './app/debugger'
 import { emitAppBeforeQuit, emitAppReady, emitAppWindowAllClosed, onAppBeforeQuit } from './libs/bootkit/lifecycle'
 import { setElectronMainDirname } from './libs/electron/location'
 import { setupChannelServer } from './services/airi/channel-server'
-import { setupBeatSyncBackgroundWindow } from './windows/beat-sync'
+import { setupBeatSync } from './windows/beat-sync'
 import { setupCaptionWindowManager } from './windows/caption'
 import { setupChatWindowReusableFunc } from './windows/chat'
 import { setupInlayWindow } from './windows/inlay'
@@ -77,7 +77,7 @@ function setupTray(params: {
   settingsWindow: () => Promise<BrowserWindow>
   captionWindow: ReturnType<typeof setupCaptionWindowManager>
   widgetsWindow: WidgetsWindowManager
-  beatSyncBackgroundWindow: BrowserWindow
+  beatSyncBgWindow: BrowserWindow
 }): void {
   once(() => {
     const trayImage = nativeImage.createFromPath(isMacOS ? macOSTrayIcon : icon).resize({ width: 16 })
@@ -105,7 +105,7 @@ function setupTray(params: {
       ...is.dev || env.MAIN_APP_DEBUG || env.APP_DEBUG
         ? [
             { type: 'header', label: 'DevTools' },
-            { label: 'Troubleshoot BeatSync...', click: () => params.beatSyncBackgroundWindow.webContents.openDevTools() },
+            { label: 'Troubleshoot BeatSync...', click: () => params.beatSyncBgWindow.webContents.openDevTools() },
             { type: 'separator' },
           ] as const // :(
         : [],
@@ -130,26 +130,38 @@ app.whenReady().then(async () => {
   const widgetsManager = injeca.provide('windows:widgets', { build: () => setupWidgetsWindowManager() })
   const noticeWindow = injeca.provide('windows:notice', { build: () => setupNoticeWindowManager() })
 
-  // This is a background window
-  const beatSyncBackgroundWindow = injeca.provide('windows:beat-sync', {
-    build: () => setupBeatSyncBackgroundWindow(),
+  // BeatSync will create a background window to capture and process audio.
+  const beatSync = injeca.provide('windows:beat-sync', {
+    build: () => setupBeatSync(),
   })
-
   const settingsWindow = injeca.provide('windows:settings', {
-    dependsOn: { widgetsManager, beatSyncBackgroundWindow },
-    build: ({ dependsOn }) => setupSettingsWindowReusableFunc(dependsOn),
+    dependsOn: { widgetsManager, beatSync },
+    build: async ({ dependsOn }) => async () => {
+      const { beatSync: _, ...setupArgs } = dependsOn
+      const window = await setupSettingsWindowReusableFunc(setupArgs)()
+      dependsOn.beatSync.dispatchTo(window)
+      return window
+    },
   })
   const mainWindow = injeca.provide('windows:main', {
-    dependsOn: { settingsWindow, chatWindow, widgetsManager, noticeWindow, beatSyncBackgroundWindow },
-    build: async ({ dependsOn }) => setupMainWindow(dependsOn),
+    dependsOn: { settingsWindow, chatWindow, widgetsManager, noticeWindow, beatSync },
+    build: async ({ dependsOn }) => {
+      const { beatSync: _, ...setupArgs } = dependsOn
+      const window = await setupMainWindow(setupArgs)
+      dependsOn.beatSync.dispatchTo(window)
+      return window
+    },
   })
   const captionWindow = injeca.provide('windows:caption', {
     dependsOn: { mainWindow },
     build: async ({ dependsOn }) => setupCaptionWindowManager(dependsOn),
   })
   const tray = injeca.provide('app:tray', {
-    dependsOn: { mainWindow, settingsWindow, captionWindow, widgetsWindow: widgetsManager, beatSyncBackgroundWindow },
-    build: async ({ dependsOn }) => setupTray(dependsOn),
+    dependsOn: { mainWindow, settingsWindow, captionWindow, widgetsWindow: widgetsManager, beatSync },
+    build: async ({ dependsOn }) => {
+      const { beatSync, ...setupArgs } = dependsOn
+      return setupTray({ ...setupArgs, beatSyncBgWindow: beatSync.window })
+    },
   })
   injeca.invoke({
     dependsOn: { mainWindow, tray, channelServerModule },
diff --git a/apps/stage-tamagotchi/src/main/windows/beat-sync/index.ts b/apps/stage-tamagotchi/src/main/windows/beat-sync/index.ts
index 923a833a9..b54fb3625 100644
--- a/apps/stage-tamagotchi/src/main/windows/beat-sync/index.ts
+++ b/apps/stage-tamagotchi/src/main/windows/beat-sync/index.ts
@@ -1,11 +1,14 @@
 import { dirname, join, resolve } from 'node:path'
 import { fileURLToPath } from 'node:url'
 
-import { BrowserWindow } from 'electron'
+import { defineInvoke, defineInvokeHandler } from '@moeru/eventa'
+import { createContext } from '@moeru/eventa/adapters/electron/main'
+import { beatSyncRequestSignalBeat, beatSyncSignalBeat } from '@proj-airi/stage-shared'
+import { BrowserWindow, ipcMain } from 'electron'
 
 import { baseUrl, getElectronMainDirname, load } from '../../libs/electron/location'
 
-export async function setupBeatSyncBackgroundWindow() {
+export async function setupBeatSync() {
   const window = new BrowserWindow({
     show: false,
     webPreferences: {
@@ -13,6 +16,16 @@ export async function setupBeatSyncBackgroundWindow() {
       sandbox: false,
     },
   })
+
   await load(window, baseUrl(resolve(getElectronMainDirname(), '..', 'renderer'), 'beat-sync.html'))
-  return window
+  return {
+    window,
+    dispatchTo: (window: BrowserWindow) => {
+      const context = createContext(ipcMain, window).context
+      const signalBeat = defineInvoke(context, beatSyncSignalBeat)
+      const removeHandler = defineInvokeHandler(context, beatSyncRequestSignalBeat, async e => signalBeat(e))
+      window.on('closed', () => removeHandler())
+      return removeHandler
+    },
+  }
 }
diff --git a/apps/stage-tamagotchi/src/renderer/beat-sync.main.ts b/apps/stage-tamagotchi/src/renderer/beat-sync.main.ts
index f4842bebc..5a59a80dd 100644
--- a/apps/stage-tamagotchi/src/renderer/beat-sync.main.ts
+++ b/apps/stage-tamagotchi/src/renderer/beat-sync.main.ts
@@ -1,13 +1,11 @@
 import { defineInvoke, defineInvokeHandler } from '@moeru/eventa'
 import { createContext } from '@moeru/eventa/adapters/electron/renderer'
-import { createDetector, StageEnvironment } from '@proj-airi/stage-shared'
-
-import { beatSyncSignalBeat, beatSyncToggle } from '../shared/eventa'
+import { beatSyncRequestSignalBeat, beatSyncToggle, createBeatSyncDetector, StageEnvironment } from '@proj-airi/stage-shared'
 
 const { ipcRenderer } = window.electron
 
 const context = createContext(ipcRenderer).context
-const signalBeat = defineInvoke(context, beatSyncSignalBeat)
+const requestSignalBeat = defineInvoke(context, beatSyncRequestSignalBeat)
 
 function enableLoopbackAudio() {
   // electron-audio-loopback currently registers this handler internally
@@ -19,13 +17,13 @@ function disableLoopbackAudio() {
   return ipcRenderer.invoke('disable-loopback-audio')
 }
 
-const detector = createDetector({
+const detector = createBeatSyncDetector({
   env: StageEnvironment.Tamagotchi,
   enableLoopbackAudio,
   disableLoopbackAudio,
 })
 
-detector.on('beat', () => signalBeat())
+detector.on('beat', e => requestSignalBeat(e))
 
 defineInvokeHandler(context, beatSyncToggle, async (enabled) => {
   if (enabled) {
diff --git a/apps/stage-tamagotchi/src/shared/eventa.ts b/apps/stage-tamagotchi/src/shared/eventa.ts
index 104a64ea7..ea5379384 100644
--- a/apps/stage-tamagotchi/src/shared/eventa.ts
+++ b/apps/stage-tamagotchi/src/shared/eventa.ts
@@ -71,7 +71,4 @@ export const widgetsRemoveEvent = defineEventa<{ id: string }>('eventa:event:ele
 export const widgetsClearEvent = defineEventa('eventa:event:electron:windows:widgets:clear')
 export const widgetsUpdateEvent = defineEventa<{ id: string, componentProps?: Record<string, any> }>('eventa:event:electron:windows:widgets:update')
 
-export const beatSyncToggle = defineInvokeEventa<void, boolean>('eventa:event:electron:beat-sync:toggle')
-export const beatSyncSignalBeat = defineInvokeEventa<void, void>('eventa:event:electron:beat-sync:signal-beat')
-
 export { electron } from './electron'
diff --git a/packages/stage-shared/package.json b/packages/stage-shared/package.json
index 4d21951d4..0727f7c45 100644
--- a/packages/stage-shared/package.json
+++ b/packages/stage-shared/package.json
@@ -23,6 +23,7 @@
   },
   "devDependencies": {
     "@electron-toolkit/preload": "^3.0.2",
+    "@moeru/eventa": "^0.3.0",
     "@nekopaw/tempora": "0.3.1-alpha.1"
   }
 }
diff --git a/packages/stage-shared/src/beat-sync.ts b/packages/stage-shared/src/beat-sync.ts
index 0671dd1ce..122102902 100644
--- a/packages/stage-shared/src/beat-sync.ts
+++ b/packages/stage-shared/src/beat-sync.ts
@@ -2,29 +2,30 @@ import type { Analyser, AnalyserBeatEvent, AnalyserWorkletParameters } from '@ne
 
 import analyserWorklet from '@nekopaw/tempora/worklet?url'
 
+import { defineInvokeEventa } from '@moeru/eventa'
 import { startAnalyser as startTemporaAnalyser } from '@nekopaw/tempora'
 
 import { StageEnvironment } from './environment'
 
-export interface DetectorEventMap {
+export interface BeatSyncDetectorEventMap {
   stateChange: (isActive: boolean) => void
   beat: (e: AnalyserBeatEvent) => void
 }
 
-export interface Detector {
+export interface BeatSyncDetector {
   start: (createSource: (context: AudioContext) => Promise<AudioNode>) => Promise<void>
   updateParameters: (params: Partial<AnalyserWorkletParameters>) => void
   startScreenCapture: () => Promise<void>
   stop: () => void
-  on: <E extends keyof DetectorEventMap>(event: E, listener: DetectorEventMap[E]) => void
-  off: <E extends keyof DetectorEventMap>(event: E, listener: DetectorEventMap[E]) => void
+  on: <E extends keyof BeatSyncDetectorEventMap>(event: E, listener: BeatSyncDetectorEventMap[E]) => void
+  off: <E extends keyof BeatSyncDetectorEventMap>(event: E, listener: BeatSyncDetectorEventMap[E]) => void
   readonly isActive: boolean
   readonly context: AudioContext | undefined
   readonly analyser: Analyser | undefined
   readonly source: AudioNode | undefined
 }
 
-export type CreateDetectorOptions = |
+export type CreateBeatSyncDetectorOptions = |
   {
     env: StageEnvironment.Tamagotchi
     enableLoopbackAudio: () => Promise<any>
@@ -34,7 +35,7 @@ export type CreateDetectorOptions = |
     env: StageEnvironment.Web
   }
 
-export function createDetector(options: CreateDetectorOptions): Detector {
+export function createBeatSyncDetector(options: CreateBeatSyncDetectorOptions): BeatSyncDetector {
   let context: AudioContext | undefined
   let analyser: Analyser | undefined
   let source: AudioNode | undefined
@@ -42,12 +43,12 @@ export function createDetector(options: CreateDetectorOptions): Detector {
 
   let stopSource: (() => void) | undefined
 
-  const listeners: { [K in keyof DetectorEventMap]: Array<(...args: any) => void> } = {
+  const listeners: { [K in keyof BeatSyncDetectorEventMap]: Array<(...args: any) => void> } = {
     stateChange: [],
     beat: [],
   }
 
-  const emit = <E extends keyof DetectorEventMap>(event: E, ...args: Parameters<DetectorEventMap[E]>) => {
+  const emit = <E extends keyof BeatSyncDetectorEventMap>(event: E, ...args: Parameters<BeatSyncDetectorEventMap[E]>) => {
     listeners[event].forEach(listener => listener(...args))
   }
 
@@ -161,7 +162,7 @@ export function createDetector(options: CreateDetectorOptions): Detector {
     updateParameters,
     startScreenCapture,
     stop,
-    on: <E extends keyof DetectorEventMap>(event: E, listener: DetectorEventMap[E]) => {
+    on: <E extends keyof BeatSyncDetectorEventMap>(event: E, listener: BeatSyncDetectorEventMap[E]) => {
       switch (event) {
         case 'beat':
           listeners.beat.push(listener)
@@ -170,7 +171,7 @@ export function createDetector(options: CreateDetectorOptions): Detector {
           throw new Error(`Unknown event: ${event}`)
       }
     },
-    off: (event, listener) => {
+    off: <E extends keyof BeatSyncDetectorEventMap>(event: E, listener: BeatSyncDetectorEventMap[E]) => {
       switch (event) {
         case 'beat': {
           const index = listeners.beat.indexOf(listener)
@@ -189,3 +190,7 @@ export function createDetector(options: CreateDetectorOptions): Detector {
     get source() { return source },
   }
 }
+
+export const beatSyncToggle = defineInvokeEventa<void, boolean>('eventa:event:electron:beat-sync:toggle')
+export const beatSyncRequestSignalBeat = defineInvokeEventa<void, AnalyserBeatEvent>('eventa:event:electron:beat-sync:request-signal-beat')
+export const beatSyncSignalBeat = defineInvokeEventa<void, AnalyserBeatEvent>('eventa:event:electron:beat-sync:signal-beat')
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index dd124fd1f..986351cb9 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1337,6 +1337,9 @@ importers:
       '@electron-toolkit/preload':
         specifier: ^3.0.2
         version: 3.0.2(electron@39.1.0)
+      '@moeru/eventa':
+        specifier: ^0.3.0
+        version: 0.3.0(electron@39.1.0)(h3@2.0.1-rc.5(crossws@0.4.1(srvx@0.9.4)))(web-worker@1.5.0)
       '@nekopaw/tempora':
         specifier: 0.3.1-alpha.1
         version: 0.3.1-alpha.1