diff --git a/apps/desktop/src/main/import/apple-journal/apple-journal-importer.test.ts b/apps/desktop/src/main/import/apple-journal/apple-journal-importer.test.ts
index c7074c0fb..6cb2a605b 100644
--- a/apps/desktop/src/main/import/apple-journal/apple-journal-importer.test.ts
+++ b/apps/desktop/src/main/import/apple-journal/apple-journal-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/apple-notes/apple-notes-importer.test.ts b/apps/desktop/src/main/import/apple-notes/apple-notes-importer.test.ts
index 47c203b9e..39b3f2775 100644
--- a/apps/desktop/src/main/import/apple-notes/apple-notes-importer.test.ts
+++ b/apps/desktop/src/main/import/apple-notes/apple-notes-importer.test.ts
@@ -26,7 +26,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/bear/bear-importer.test.ts b/apps/desktop/src/main/import/bear/bear-importer.test.ts
index abf3da8f2..0f71f37ce 100644
--- a/apps/desktop/src/main/import/bear/bear-importer.test.ts
+++ b/apps/desktop/src/main/import/bear/bear-importer.test.ts
@@ -17,7 +17,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/csv/csv-importer.test.ts b/apps/desktop/src/main/import/csv/csv-importer.test.ts
index 9280e287c..9d4401a85 100644
--- a/apps/desktop/src/main/import/csv/csv-importer.test.ts
+++ b/apps/desktop/src/main/import/csv/csv-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/evernote/evernote-importer.test.ts b/apps/desktop/src/main/import/evernote/evernote-importer.test.ts
index 4c0b82b6b..e0299aff3 100644
--- a/apps/desktop/src/main/import/evernote/evernote-importer.test.ts
+++ b/apps/desktop/src/main/import/evernote/evernote-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/google-keep/google-keep-importer.test.ts b/apps/desktop/src/main/import/google-keep/google-keep-importer.test.ts
index 2af1c99db..639979230 100644
--- a/apps/desktop/src/main/import/google-keep/google-keep-importer.test.ts
+++ b/apps/desktop/src/main/import/google-keep/google-keep-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/html/html-importer.test.ts b/apps/desktop/src/main/import/html/html-importer.test.ts
index 20071b457..9283d71b9 100644
--- a/apps/desktop/src/main/import/html/html-importer.test.ts
+++ b/apps/desktop/src/main/import/html/html-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/import-context.test.ts b/apps/desktop/src/main/import/import-context.test.ts
index 53ee69cd5..f83c94e7a 100644
--- a/apps/desktop/src/main/import/import-context.test.ts
+++ b/apps/desktop/src/main/import/import-context.test.ts
@@ -2,7 +2,11 @@ import { describe, it, expect, vi, beforeEach } from 'vitest'
 
 const send = vi.fn()
 vi.mock('electron', () => ({
-  BrowserWindow: { getAllWindows: () => [{ webContents: { send } }] }
+  BrowserWindow: {
+    getAllWindows: () => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+    ]
+  }
 }))
 
 import { createImportContext } from './import-context'
diff --git a/apps/desktop/src/main/import/import-context.ts b/apps/desktop/src/main/import/import-context.ts
index c791a2b62..a5a2b314b 100644
--- a/apps/desktop/src/main/import/import-context.ts
+++ b/apps/desktop/src/main/import/import-context.ts
@@ -1,6 +1,6 @@
-import { BrowserWindow } from 'electron'
 import { ImportChannels } from '@memry/contracts/import-channels'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import type { ImportContext, ImportProgress, ImportSummary } from './types'
 
 const logger = createLogger('Import')
@@ -37,9 +37,7 @@ export function createImportContext(importId: string, signal: AbortSignal): Impo
       done,
       summary: done ? toSummary() : undefined
     }
-    for (const win of BrowserWindow.getAllWindows()) {
-      win.webContents.send(ImportChannels.events.PROGRESS, payload)
-    }
+    broadcastToAllWindows(ImportChannels.events.PROGRESS, payload)
   }
 
   return {
diff --git a/apps/desktop/src/main/import/markdown/markdown-importer.test.ts b/apps/desktop/src/main/import/markdown/markdown-importer.test.ts
index d0e4af20a..6f529f9e7 100644
--- a/apps/desktop/src/main/import/markdown/markdown-importer.test.ts
+++ b/apps/desktop/src/main/import/markdown/markdown-importer.test.ts
@@ -16,7 +16,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/notion/notion-importer.test.ts b/apps/desktop/src/main/import/notion/notion-importer.test.ts
index 403d9c150..afa7b575f 100644
--- a/apps/desktop/src/main/import/notion/notion-importer.test.ts
+++ b/apps/desktop/src/main/import/notion/notion-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/import/roam/roam-importer.test.ts b/apps/desktop/src/main/import/roam/roam-importer.test.ts
index 6a6b98777..76195795b 100644
--- a/apps/desktop/src/main/import/roam/roam-importer.test.ts
+++ b/apps/desktop/src/main/import/roam/roam-importer.test.ts
@@ -15,7 +15,11 @@ import { createNoteDerivedStateProjector } from '../../projections/projectors/no
 vi.mock('electron', () => {
   const send = vi.fn()
   return {
-    BrowserWindow: { getAllWindows: vi.fn(() => [{ webContents: { send } }]) },
+    BrowserWindow: {
+      getAllWindows: vi.fn(() => [
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
+    },
     shell: { openPath: vi.fn(() => Promise.resolve('')), showItemInFolder: vi.fn() }
   }
 })
diff --git a/apps/desktop/src/main/ipc/ai-inline-handlers.test.ts b/apps/desktop/src/main/ipc/ai-inline-handlers.test.ts
index 04e55725a..bb288704b 100644
--- a/apps/desktop/src/main/ipc/ai-inline-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/ai-inline-handlers.test.ts
@@ -16,7 +16,7 @@ const mocks = vi.hoisted(() => {
     BrowserWindow: {
       getAllWindows: vi.fn()
     },
-    webContents: { send: vi.fn() },
+    webContents: { isDestroyed: () => false, send: vi.fn() },
     startChatServer: vi.fn(),
     stopChatServer: vi.fn(),
     getServerPort: vi.fn(),
@@ -74,7 +74,9 @@ describe('AI inline IPC handlers', () => {
     mocks.getSetting.mockReturnValue(
       JSON.stringify({ enabled: true, provider: 'openai', apiKey: 'sk-real', model: 'gpt-4o-mini' })
     )
-    mocks.BrowserWindow.getAllWindows.mockReturnValue([{ webContents: mocks.webContents }])
+    mocks.BrowserWindow.getAllWindows.mockReturnValue([
+      { isDestroyed: () => false, webContents: mocks.webContents }
+    ])
     mocks.getServerPort.mockReturnValue(3434)
     mocks.startChatServer.mockResolvedValue(4545)
     mocks.stopChatServer.mockResolvedValue(undefined)
diff --git a/apps/desktop/src/main/ipc/ai-inline-handlers.ts b/apps/desktop/src/main/ipc/ai-inline-handlers.ts
index c7a5944f5..d397aaabf 100644
--- a/apps/desktop/src/main/ipc/ai-inline-handlers.ts
+++ b/apps/desktop/src/main/ipc/ai-inline-handlers.ts
@@ -1,10 +1,11 @@
-import { ipcMain, BrowserWindow } from 'electron'
+import { ipcMain } from 'electron'
 import { AIInlineChannels, AI_INLINE_SETTINGS_DEFAULTS } from '@memry/contracts/ai-inline-channels'
 import type { AIInlineSettings } from '@memry/contracts/ai-inline-channels'
 
 import { startChatServer, stopChatServer, getServerPort } from '../ai-inline/ai-chat-server'
 import { getDatabase } from '../database'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { getSetting, setSetting } from '../settings/settings-store'
 import { isConnectionRefusedError, markExpectedCondition } from '../telemetry/expected-conditions'
 import { withErrorHandler } from './validate'
@@ -61,11 +62,9 @@ export function registerAIInlineHandlers(): void {
       const updated = { ...current, ...updates }
       setSetting(db, SETTINGS_KEY, JSON.stringify(updated))
 
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(AIInlineChannels.events.SERVER_READY, {
-          key: SETTINGS_KEY,
-          value: maskApiKey(updated)
-        })
+      broadcastToAllWindows(AIInlineChannels.events.SERVER_READY, {
+        key: SETTINGS_KEY,
+        value: maskApiKey(updated)
       })
 
       return { success: true }
diff --git a/apps/desktop/src/main/ipc/auth-device-handlers.test.ts b/apps/desktop/src/main/ipc/auth-device-handlers.test.ts
index 3629ae798..9194855c0 100644
--- a/apps/desktop/src/main/ipc/auth-device-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/auth-device-handlers.test.ts
@@ -339,8 +339,8 @@ describe('auth-device handlers', () => {
       await invokeHandler(SYNC_CHANNELS.AUTH_REQUEST_OTP, { email: 'user@example.com' })
 
       // then clipboard polling is started - verified by advancing timers
-      const mockWebContents = { send: vi.fn() }
-      const mockWindow = { webContents: mockWebContents }
+      const mockWebContents = { isDestroyed: () => false, send: vi.fn() }
+      const mockWindow = { isDestroyed: () => false, webContents: mockWebContents }
       mockGetAllWindows.mockReturnValue([mockWindow])
       mockClipboardReadText.mockReturnValue('123456')
 
@@ -368,8 +368,10 @@ describe('auth-device handlers', () => {
         code: '123456'
       })
 
-      const mockWebContents = { send: vi.fn() }
-      mockGetAllWindows.mockReturnValue([{ webContents: mockWebContents }])
+      const mockWebContents = { isDestroyed: () => false, send: vi.fn() }
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: mockWebContents }
+      ])
       mockClipboardReadText.mockReturnValue('654321')
 
       vi.advanceTimersByTime(2000)
@@ -384,8 +386,10 @@ describe('auth-device handlers', () => {
       mockPostToServer.mockResolvedValue({ success: true })
       await invokeHandler(SYNC_CHANNELS.AUTH_REQUEST_OTP, { email: 'user@example.com' })
 
-      const mockWebContents = { send: vi.fn() }
-      mockGetAllWindows.mockReturnValue([{ webContents: mockWebContents }])
+      const mockWebContents = { isDestroyed: () => false, send: vi.fn() }
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: mockWebContents }
+      ])
       mockClipboardReadText.mockReturnValue('not-a-code')
 
       // #when
@@ -404,8 +408,10 @@ describe('auth-device handlers', () => {
       // #when - advance past 10-minute timeout
       vi.advanceTimersByTime(10 * 60 * 1000 + 1000)
 
-      const mockWebContents = { send: vi.fn() }
-      mockGetAllWindows.mockReturnValue([{ webContents: mockWebContents }])
+      const mockWebContents = { isDestroyed: () => false, send: vi.fn() }
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: mockWebContents }
+      ])
       mockClipboardReadText.mockReturnValue('123456')
 
       vi.advanceTimersByTime(2000)
@@ -801,7 +807,9 @@ describe('auth-device handlers', () => {
     it('removes remote devices locally without revoking the current renderer, and tolerates server 404s', async () => {
       registerAuthDeviceHandlers()
       const send = vi.fn()
-      mockGetAllWindows.mockReturnValue([{ webContents: { send } }])
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
 
       await expect(
         invokeHandler(SYNC_CHANNELS.REMOVE_DEVICE, { deviceId: 'dev-remote' })
@@ -837,7 +845,9 @@ describe('auth-device handlers', () => {
     it('renames a device locally and broadcasts the new name', async () => {
       registerAuthDeviceHandlers()
       const send = vi.fn()
-      mockGetAllWindows.mockReturnValue([{ webContents: { send } }])
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
 
       await expect(
         invokeHandler(SYNC_CHANNELS.RENAME_DEVICE, {
diff --git a/apps/desktop/src/main/ipc/auth-device-handlers.ts b/apps/desktop/src/main/ipc/auth-device-handlers.ts
index 5d83305ae..6915d07c7 100644
--- a/apps/desktop/src/main/ipc/auth-device-handlers.ts
+++ b/apps/desktop/src/main/ipc/auth-device-handlers.ts
@@ -1,4 +1,4 @@
-import { BrowserWindow, clipboard, ipcMain } from 'electron'
+import { clipboard, ipcMain } from 'electron'
 
 import { syncDevices } from '@memry/db-schema/schema/sync-devices'
 import { KEYCHAIN_ENTRIES } from '@memry/contracts/crypto'
@@ -43,6 +43,7 @@ import {
 } from '../sync/linking-service'
 import { getValidAccessToken, retrieveToken, storeToken } from '../sync/token-manager'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { registerCommand } from './lib/register-command'
 
 const logger = createLogger('IPC:Sync:Device')
@@ -193,10 +194,7 @@ const startOtpClipboardDetection = (): void => {
     lastClipboardValue = text
 
     if (OTP_PATTERN.test(text)) {
-      const windows = BrowserWindow.getAllWindows()
-      for (const win of windows) {
-        win.webContents.send(SYNC_EVENTS.OTP_DETECTED, { code: text })
-      }
+      broadcastToAllWindows(SYNC_EVENTS.OTP_DETECTED, { code: text })
     }
   }, OTP_CLIPBOARD_POLL_MS)
 
@@ -507,12 +505,10 @@ export function registerAuthDeviceHandlers(): void {
           .run()
       }
 
-      for (const win of BrowserWindow.getAllWindows()) {
-        win.webContents.send(SYNC_EVENTS.DEVICE_RENAMED, {
-          deviceId: input.deviceId,
-          name: input.newName
-        })
-      }
+      broadcastToAllWindows(SYNC_EVENTS.DEVICE_RENAMED, {
+        deviceId: input.deviceId,
+        name: input.newName
+      })
 
       logger.info(`Device renamed: ${input.deviceId} → ${input.newName}`)
       return { success: true }
diff --git a/apps/desktop/src/main/ipc/auth-oauth-handlers.test.ts b/apps/desktop/src/main/ipc/auth-oauth-handlers.test.ts
index 214839d93..6f99e64c7 100644
--- a/apps/desktop/src/main/ipc/auth-oauth-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/auth-oauth-handlers.test.ts
@@ -201,7 +201,9 @@ describe('auth-oauth handlers', () => {
   describe('AUTH_INIT_OAUTH', () => {
     it('opens the provider URL and relays successful loopback callbacks', async () => {
       const send = vi.fn()
-      mockGetAllWindows.mockReturnValue([{ webContents: { send } }])
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
       registerAuthOAuthHandlers()
 
       const result = await invokeHandler(SYNC_CHANNELS.AUTH_INIT_OAUTH, { provider: 'google' })
@@ -247,7 +249,9 @@ describe('auth-oauth handlers', () => {
 
     it('relays OAuth errors and rejects malformed provider responses', async () => {
       const send = vi.fn()
-      mockGetAllWindows.mockReturnValue([{ webContents: { send } }])
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
       registerAuthOAuthHandlers()
 
       await invokeHandler(SYNC_CHANNELS.AUTH_INIT_OAUTH, { provider: 'google' })
diff --git a/apps/desktop/src/main/ipc/auth-oauth-handlers.ts b/apps/desktop/src/main/ipc/auth-oauth-handlers.ts
index da0ebfeb2..b639f3b45 100644
--- a/apps/desktop/src/main/ipc/auth-oauth-handlers.ts
+++ b/apps/desktop/src/main/ipc/auth-oauth-handlers.ts
@@ -1,4 +1,4 @@
-import { BrowserWindow, ipcMain, shell } from 'electron'
+import { ipcMain, shell } from 'electron'
 import http from 'node:http'
 import https from 'node:https'
 
@@ -19,6 +19,7 @@ import { startGoogleCalendarSyncRunner } from '../calendar/google/sync-service'
 import { teardownSession } from '../sync/session-teardown'
 import { refreshAccessToken, storeToken } from '../sync/token-manager'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { registerCommand } from './lib/register-command'
 import {
   clearPendingRecoveryPhrase,
@@ -185,9 +186,7 @@ export function registerAuthOAuthHandlers(): void {
           const cbState = reqUrl.searchParams.get('state')
           if (cbState) oauthSessions.delete(cbState)
 
-          for (const win of BrowserWindow.getAllWindows()) {
-            win.webContents.send(SYNC_EVENTS.OAUTH_ERROR, { error: oauthError })
-          }
+          broadcastToAllWindows(SYNC_EVENTS.OAUTH_ERROR, { error: oauthError })
 
           shutdownLoopbackServer()
           return
@@ -200,9 +199,7 @@ export function registerAuthOAuthHandlers(): void {
         res.end(SUCCESS_HTML)
 
         if (code && cbState) {
-          for (const win of BrowserWindow.getAllWindows()) {
-            win.webContents.send(SYNC_EVENTS.OAUTH_CALLBACK, { code, state: cbState })
-          }
+          broadcastToAllWindows(SYNC_EVENTS.OAUTH_CALLBACK, { code, state: cbState })
         }
 
         shutdownLoopbackServer()
diff --git a/apps/desktop/src/main/ipc/bookmarks-handlers.test.ts b/apps/desktop/src/main/ipc/bookmarks-handlers.test.ts
index ecf3eaa38..4369f7e2f 100644
--- a/apps/desktop/src/main/ipc/bookmarks-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/bookmarks-handlers.test.ts
@@ -24,7 +24,9 @@ vi.mock('electron', () => ({
     })
   },
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: mockSend } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: mockSend } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/ipc/bookmarks-handlers.ts b/apps/desktop/src/main/ipc/bookmarks-handlers.ts
index 8db828b17..ccfe20c42 100644
--- a/apps/desktop/src/main/ipc/bookmarks-handlers.ts
+++ b/apps/desktop/src/main/ipc/bookmarks-handlers.ts
@@ -5,7 +5,7 @@
  * @module ipc/bookmarks-handlers
  */
 
-import { ipcMain, BrowserWindow } from 'electron'
+import { ipcMain } from 'electron'
 import {
   BookmarksChannels,
   BookmarkItemTypes,
@@ -23,6 +23,7 @@ import {
 } from '@memry/contracts/bookmarks-api'
 import { bookmarkSyncId } from '@memry/contracts/bookmark-types'
 import { createValidatedHandler, createStringHandler } from './validate'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { requireDatabase, getIndexDatabase } from '../database'
 import { bookmarkQueries, notesQueries, tasksQueries } from '../bookmarks/store'
 import {
@@ -35,9 +36,7 @@ import {
  * Emit bookmark event to all windows
  */
 function emitBookmarkEvent(channel: string, data: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, data)
-  })
+  broadcastToAllWindows(channel, data)
 }
 
 /**
diff --git a/apps/desktop/src/main/ipc/calendar-handlers.test.ts b/apps/desktop/src/main/ipc/calendar-handlers.test.ts
index 0c34d6683..81310b112 100644
--- a/apps/desktop/src/main/ipc/calendar-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/calendar-handlers.test.ts
@@ -53,7 +53,9 @@ vi.mock('electron', () => ({
     })
   },
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: webContentsSend } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: webContentsSend } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/ipc/calendar-handlers.ts b/apps/desktop/src/main/ipc/calendar-handlers.ts
index 0e6ef6915..ec82c8345 100644
--- a/apps/desktop/src/main/ipc/calendar-handlers.ts
+++ b/apps/desktop/src/main/ipc/calendar-handlers.ts
@@ -1,4 +1,4 @@
-import { BrowserWindow, ipcMain } from 'electron'
+import { ipcMain } from 'electron'
 import { and, asc, eq, inArray, isNull } from 'drizzle-orm'
 import { CalendarChannels } from '@memry/contracts/ipc-channels'
 import {
@@ -39,6 +39,7 @@ import { calendarExternalEvents } from '@memry/db-schema/schema/calendar-externa
 import { calendarSources } from '@memry/db-schema/schema/calendar-sources'
 import { calendarBindings } from '@memry/db-schema/schema/calendar-bindings'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { trackCalendar } from './calendar-telemetry'
 import { requireDatabase, getIndexDatabase, type DataDb } from '../database'
 import { generateId } from '../lib/id'
@@ -89,9 +90,7 @@ import {
 const log = createLogger('IPC:Calendar')
 
 function emitCalendarChanged(event: CalendarChangedEvent): void {
-  for (const win of BrowserWindow.getAllWindows()) {
-    win.webContents.send(CalendarChannels.events.CHANGED, event)
-  }
+  broadcastToAllWindows(CalendarChannels.events.CHANGED, event)
 }
 
 function mapCalendarEvent(row: typeof calendarEvents.$inferSelect): CalendarEventRecord {
diff --git a/apps/desktop/src/main/ipc/canvas-handlers.ts b/apps/desktop/src/main/ipc/canvas-handlers.ts
index 063c59cef..626d287b6 100644
--- a/apps/desktop/src/main/ipc/canvas-handlers.ts
+++ b/apps/desktop/src/main/ipc/canvas-handlers.ts
@@ -27,6 +27,7 @@ import {
   type CanvasUpdateResponse
 } from '@memry/contracts/canvas-api'
 import { createValidatedHandler, createHandler, createStringHandler } from './validate'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { getCanvasContext, disposeCanvasVaultKey } from '../canvas/vault-key'
 import { forgetWindow, markCanvasClosed, markCanvasOpen } from '../canvas/live-registry'
 import { createCanvas, deleteCanvas, getCanvas, listCanvases, updateCanvas } from '../canvas/store'
@@ -46,9 +47,7 @@ function emitCanvasEvent(
   channel: string,
   data: CanvasCreatedEvent | CanvasUpdatedEvent | CanvasDeletedEvent | CanvasTooLargeEvent
 ): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, data)
-  })
+  broadcastToAllWindows(channel, data)
 }
 
 /** Windows already carrying a 'closed' listener for live-canvas cleanup. */
diff --git a/apps/desktop/src/main/ipc/journal-handlers.test.ts b/apps/desktop/src/main/ipc/journal-handlers.test.ts
index 5b7efd1b4..617c07a49 100644
--- a/apps/desktop/src/main/ipc/journal-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/journal-handlers.test.ts
@@ -24,7 +24,9 @@ vi.mock('electron', () => ({
     })
   },
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: vi.fn() } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: vi.fn() } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/ipc/journal-handlers.ts b/apps/desktop/src/main/ipc/journal-handlers.ts
index 90e289b8d..5e10ac144 100644
--- a/apps/desktop/src/main/ipc/journal-handlers.ts
+++ b/apps/desktop/src/main/ipc/journal-handlers.ts
@@ -5,7 +5,7 @@
  * @module ipc/journal-handlers
  */
 
-import { ipcMain, BrowserWindow } from 'electron'
+import { ipcMain } from 'electron'
 import { JournalChannels } from '@memry/contracts/ipc-channels'
 import {
   GetEntryInputSchema,
@@ -24,6 +24,7 @@ import {
   type GetAllTagsOutput
 } from '@memry/contracts/journal-api'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { createValidatedHandler, createHandler } from './validate'
 import {
   readJournalEntry,
@@ -69,9 +70,7 @@ const logger = createLogger('IPC:Journal')
  * Emit journal event to all windows.
  */
 function emitJournalEvent(channel: string, payload: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, payload)
-  })
+  broadcastToAllWindows(channel, payload)
 }
 
 // ============================================================================
diff --git a/apps/desktop/src/main/ipc/locale-handler.test.ts b/apps/desktop/src/main/ipc/locale-handler.test.ts
index f75a88cb0..44a59cdfc 100644
--- a/apps/desktop/src/main/ipc/locale-handler.test.ts
+++ b/apps/desktop/src/main/ipc/locale-handler.test.ts
@@ -1,7 +1,10 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 const hoisted = vi.hoisted(() => ({
-  windows: [] as Array<{ webContents: { send: ReturnType<typeof vi.fn> } }>,
+  windows: [] as Array<{
+    isDestroyed: () => boolean
+    webContents: { isDestroyed: () => boolean; send: ReturnType<typeof vi.fn> }
+  }>,
   getDatabase: vi.fn(() => ({})),
   getSetting: vi.fn(() => null),
   setSetting: vi.fn(),
@@ -73,7 +76,9 @@ describe('locale handler', () => {
     const send = vi.fn()
     const mockI18n = { changeLanguage: vi.fn(), language: 'en' } as any
     const rebuildMenu = vi.fn()
-    hoisted.windows = [{ webContents: { send } }]
+    hoisted.windows = [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+    ]
     hoisted.getSetting.mockReturnValue(JSON.stringify({ theme: 'dark', language: 'en' }))
 
     registerLocaleHandlers(mockI18n, rebuildMenu)
@@ -105,7 +110,9 @@ describe('locale handler', () => {
     const send = vi.fn()
     const mockI18n = { changeLanguage: vi.fn(), language: 'en' } as any
     const rebuildMenu = vi.fn()
-    hoisted.windows = [{ webContents: { send } }]
+    hoisted.windows = [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+    ]
     hoisted.getCurrentVaultPath.mockReturnValue(null)
     hoisted.getDatabase.mockImplementation(() => {
       throw new Error('Database not initialized')
diff --git a/apps/desktop/src/main/ipc/locale-handler.ts b/apps/desktop/src/main/ipc/locale-handler.ts
index 7e27ed414..a83f087e7 100644
--- a/apps/desktop/src/main/ipc/locale-handler.ts
+++ b/apps/desktop/src/main/ipc/locale-handler.ts
@@ -1,10 +1,11 @@
-import { BrowserWindow, ipcMain } from 'electron'
+import { ipcMain } from 'electron'
 import { LocaleChannels } from '@memry/contracts/ipc-channels'
 import { LocaleSchema, SUPPORTED_LOCALES, type Locale } from '@memry/contracts/locale-api'
 import { GENERAL_SETTINGS_DEFAULTS, type GeneralSettings } from '@memry/contracts/settings-schemas'
 import type { I18nInstance } from '@memry/i18n/main'
 import { getDatabase, type DataDb } from '../database'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { getSetting, setSetting } from '../settings/settings-store'
 import { getCurrentVaultPath, setStoredLocale } from '../store'
 import { writePreferences } from '../vault/vault-preferences'
@@ -81,9 +82,7 @@ export function registerLocaleHandlers(i18n: I18nInstance, rebuildMenu: RebuildM
       await i18n.changeLanguage(locale)
       rebuildMenu(locale)
 
-      for (const win of BrowserWindow.getAllWindows()) {
-        win.webContents.send(LocaleChannels.Changed, locale)
-      }
+      broadcastToAllWindows(LocaleChannels.Changed, locale)
 
       activeLocale = locale
       logger.info('Locale changed', { locale })
diff --git a/apps/desktop/src/main/ipc/saved-filters-handlers.test.ts b/apps/desktop/src/main/ipc/saved-filters-handlers.test.ts
index 2186d239a..bf382d6e2 100644
--- a/apps/desktop/src/main/ipc/saved-filters-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/saved-filters-handlers.test.ts
@@ -24,7 +24,9 @@ vi.mock('electron', () => ({
     })
   },
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: mockSend } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: mockSend } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/ipc/saved-filters-handlers.ts b/apps/desktop/src/main/ipc/saved-filters-handlers.ts
index 431080c17..27ac33b78 100644
--- a/apps/desktop/src/main/ipc/saved-filters-handlers.ts
+++ b/apps/desktop/src/main/ipc/saved-filters-handlers.ts
@@ -5,7 +5,7 @@
  * @module ipc/saved-filters-handlers
  */
 
-import { ipcMain, BrowserWindow } from 'electron'
+import { ipcMain } from 'electron'
 import { SavedFiltersChannels } from '@memry/contracts/ipc-channels'
 import {
   SavedFilterCreateSchema,
@@ -17,6 +17,7 @@ import {
 import { createValidatedHandler, createHandler } from './validate'
 import { requireDatabase } from '../database'
 import { generateId } from '../lib/id'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import * as savedFiltersStore from '../settings/saved-filters-store'
 import {
   syncFilterCreate,
@@ -28,9 +29,7 @@ import {
  * Emit saved filter event to all windows
  */
 function emitSavedFilterEvent(channel: string, data: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, data)
-  })
+  broadcastToAllWindows(channel, data)
 }
 
 /**
diff --git a/apps/desktop/src/main/ipc/settings-handlers.test.ts b/apps/desktop/src/main/ipc/settings-handlers.test.ts
index 44e2771e0..7a7b3f4f4 100644
--- a/apps/desktop/src/main/ipc/settings-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/settings-handlers.test.ts
@@ -940,7 +940,7 @@ describe('settings-handlers', () => {
 
       callback?.()
       expect(mockGlobalShortcutRegister).toHaveBeenCalledWith('Control+K', expect.any(Function))
-      expect(mockSend).toHaveBeenCalledWith('quick-capture:open')
+      expect(mockSend).toHaveBeenCalledWith('quick-capture:open', undefined)
     })
   })
 
diff --git a/apps/desktop/src/main/ipc/settings-handlers.ts b/apps/desktop/src/main/ipc/settings-handlers.ts
index d73dde8d2..46bbaf546 100644
--- a/apps/desktop/src/main/ipc/settings-handlers.ts
+++ b/apps/desktop/src/main/ipc/settings-handlers.ts
@@ -7,7 +7,7 @@
  * @module main/ipc/settings-handlers
  */
 
-import { ipcMain, BrowserWindow, app, globalShortcut, systemPreferences, shell } from 'electron'
+import { ipcMain, app, globalShortcut, systemPreferences, shell } from 'electron'
 import { SettingsChannels } from '@memry/contracts/ipc-channels'
 import {
   GENERAL_SETTINGS_DEFAULTS,
@@ -38,6 +38,7 @@ import type {
 import { GRAPH_SETTINGS_DEFAULTS } from '@memry/contracts/graph-api'
 import type { GraphSettings } from '@memry/contracts/graph-api'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { getDatabase } from '../database'
 import { getSetting, setSetting, deleteSetting } from '../settings/settings-store'
 import { withErrorHandler } from './validate'
@@ -316,11 +317,9 @@ function writeGroupSettings<T extends Record<string, unknown>>(
   const updated = { ...current, ...updates }
   setSetting(db, groupKey, JSON.stringify(updated))
 
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(SettingsChannels.events.CHANGED, {
-      key: groupKey,
-      value: updates
-    })
+  broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+    key: groupKey,
+    value: updates
   })
 
   return { success: true }
@@ -358,9 +357,7 @@ export function registerSettingsHandlers(): void {
       setSetting(db, key, value)
 
       // Emit settings changed event
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(SettingsChannels.events.CHANGED, { key, value })
-      })
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, { key, value })
 
       if (SafeDimensionValueSchema.safeParse(key).success) {
         trackMainEvent('setting_changed', {
@@ -447,11 +444,9 @@ export function registerSettingsHandlers(): void {
       }
 
       // Emit settings changed event
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(SettingsChannels.events.CHANGED, {
-          key: 'journal',
-          value: settings
-        })
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+        key: 'journal',
+        value: settings
       })
 
       return { success: true }
@@ -491,11 +486,9 @@ export function registerSettingsHandlers(): void {
       }
 
       // Emit settings changed event
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(SettingsChannels.events.CHANGED, {
-          key: 'ai',
-          value: settings
-        })
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+        key: 'ai',
+        value: settings
       })
 
       return { success: true }
@@ -737,11 +730,9 @@ export function registerSettingsHandlers(): void {
       }
 
       // Emit settings changed event
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(SettingsChannels.events.CHANGED, {
-          key: 'tabs',
-          value: settings
-        })
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+        key: 'tabs',
+        value: settings
       })
 
       return { success: true }
@@ -778,11 +769,9 @@ export function registerSettingsHandlers(): void {
       }
 
       // Emit settings changed event
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(SettingsChannels.events.CHANGED, {
-          key: 'noteEditor',
-          value: settings
-        })
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+        key: 'noteEditor',
+        value: settings
       })
 
       return { success: true }
@@ -928,11 +917,9 @@ export function registerSettingsHandlers(): void {
 
     deleteSetting(db, 'keyboard')
 
-    BrowserWindow.getAllWindows().forEach((win) => {
-      win.webContents.send(SettingsChannels.events.CHANGED, {
-        key: 'keyboard',
-        value: KEYBOARD_SHORTCUTS_DEFAULTS
-      })
+    broadcastToAllWindows(SettingsChannels.events.CHANGED, {
+      key: 'keyboard',
+      value: KEYBOARD_SHORTCUTS_DEFAULTS
     })
 
     return { success: true }
@@ -990,9 +977,7 @@ export function applyGlobalCaptureShortcut(): GlobalCaptureResult {
 
   const accelerator = toElectronAccelerator(binding)
   const registered = globalShortcut.register(accelerator, () => {
-    BrowserWindow.getAllWindows().forEach((win) => {
-      if (!win.isDestroyed()) win.webContents.send('quick-capture:open')
-    })
+    broadcastToAllWindows('quick-capture:open')
   })
 
   if (!registered) {
diff --git a/apps/desktop/src/main/ipc/sync-attachment-handlers.test.ts b/apps/desktop/src/main/ipc/sync-attachment-handlers.test.ts
index 03da3bfb5..7f4b73cb2 100644
--- a/apps/desktop/src/main/ipc/sync-attachment-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/sync-attachment-handlers.test.ts
@@ -43,7 +43,9 @@ vi.mock('electron', () => ({
   BrowserWindow: {
     getAllWindows: vi.fn(() => [
       {
+        isDestroyed: () => false,
         webContents: {
+          isDestroyed: () => false,
           send: (channel: string, payload: unknown) =>
             attachmentMocks.sent.push({ channel, payload })
         }
diff --git a/apps/desktop/src/main/ipc/sync-attachment-handlers.ts b/apps/desktop/src/main/ipc/sync-attachment-handlers.ts
index e24f9cc3d..b28f36b2e 100644
--- a/apps/desktop/src/main/ipc/sync-attachment-handlers.ts
+++ b/apps/desktop/src/main/ipc/sync-attachment-handlers.ts
@@ -1,4 +1,4 @@
-import { BrowserWindow, ipcMain } from 'electron'
+import { ipcMain } from 'electron'
 import fs from 'node:fs'
 import path from 'node:path'
 import sodium from 'libsodium-wrappers-sumo'
@@ -45,6 +45,7 @@ import {
 } from '../crypto'
 import { getDatabase, isDatabaseInitialized } from '../database/client'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import {
   recordDownloadedFileSize,
   recordUploadedAttachment
@@ -80,14 +81,12 @@ const broadcastUploadProgress = (progress: TransferProgress): void => {
     progress.totalChunks > 0
       ? Math.round((progress.chunksCompleted / progress.totalChunks) * 100)
       : 0
-  for (const win of BrowserWindow.getAllWindows()) {
-    win.webContents.send(SYNC_EVENTS.UPLOAD_PROGRESS, {
-      attachmentId: progress.attachmentId,
-      sessionId: '',
-      progress: percent,
-      status: progress.phase
-    })
-  }
+  broadcastToAllWindows(SYNC_EVENTS.UPLOAD_PROGRESS, {
+    attachmentId: progress.attachmentId,
+    sessionId: '',
+    progress: percent,
+    status: progress.phase
+  })
 }
 
 const getOrCreateAttachmentService = (): AttachmentSyncService | null => {
@@ -231,13 +230,11 @@ export function registerAttachmentHandlers(): void {
           progress.totalChunks > 0
             ? Math.round((progress.chunksCompleted / progress.totalChunks) * 100)
             : 0
-        for (const win of BrowserWindow.getAllWindows()) {
-          win.webContents.send(SYNC_EVENTS.DOWNLOAD_PROGRESS, {
-            attachmentId: progress.attachmentId,
-            progress: percent,
-            status: progress.phase
-          })
-        }
+        broadcastToAllWindows(SYNC_EVENTS.DOWNLOAD_PROGRESS, {
+          attachmentId: progress.attachmentId,
+          progress: percent,
+          status: progress.phase
+        })
       })
 
       try {
@@ -370,14 +367,12 @@ export function registerAttachmentHandlers(): void {
           invalidateCachedEntitlementLimits()
         }
 
-        for (const win of BrowserWindow.getAllWindows()) {
-          win.webContents.send(SYNC_EVENTS.ATTACHMENT_UPLOAD_FAILED, {
-            noteId,
-            diskPath,
-            error: message,
-            errorCategory: category
-          })
-        }
+        broadcastToAllWindows(SYNC_EVENTS.ATTACHMENT_UPLOAD_FAILED, {
+          noteId,
+          diskPath,
+          error: message,
+          errorCategory: category
+        })
       }
     })()
   })
@@ -410,13 +405,11 @@ export function registerAttachmentHandlers(): void {
           diskPath,
           error: message
         })
-        for (const win of BrowserWindow.getAllWindows()) {
-          win.webContents.send(SYNC_EVENTS.ATTACHMENT_UPLOAD_FAILED, {
-            noteId,
-            diskPath,
-            error: message
-          })
-        }
+        broadcastToAllWindows(SYNC_EVENTS.ATTACHMENT_UPLOAD_FAILED, {
+          noteId,
+          diskPath,
+          error: message
+        })
       }
     })()
   })
diff --git a/apps/desktop/src/main/ipc/sync-core-handlers.test.ts b/apps/desktop/src/main/ipc/sync-core-handlers.test.ts
index c6a61dd9a..ab0c35498 100644
--- a/apps/desktop/src/main/ipc/sync-core-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/sync-core-handlers.test.ts
@@ -667,7 +667,9 @@ describe('sync IPC handlers', () => {
       mockGetDevicePublicKey.mockReturnValue(new Uint8Array(32).fill(8))
       mockCheckLocalKeyAgainstAccount.mockResolvedValue('mismatch')
       const send = vi.fn()
-      mockGetAllWindows.mockReturnValue([{ webContents: { send } }])
+      mockGetAllWindows.mockReturnValue([
+        { isDestroyed: () => false, webContents: { isDestroyed: () => false, send } }
+      ])
 
       await checkSyncIntegrity()
 
diff --git a/apps/desktop/src/main/ipc/sync-core-handlers.ts b/apps/desktop/src/main/ipc/sync-core-handlers.ts
index b9bed72bb..12a12e441 100644
--- a/apps/desktop/src/main/ipc/sync-core-handlers.ts
+++ b/apps/desktop/src/main/ipc/sync-core-handlers.ts
@@ -1,4 +1,4 @@
-import { BrowserWindow, ipcMain } from 'electron'
+import { ipcMain } from 'electron'
 import sodium from 'libsodium-wrappers-sumo'
 
 import { syncDevices } from '@memry/db-schema/schema/sync-devices'
@@ -22,6 +22,7 @@ import { getDatabase, isDatabaseInitialized } from '../database/client'
 import { getFromServer } from '../sync/http-client'
 
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { withErrorHandler } from './validate'
 import { registerCommand } from './lib/register-command'
 import { getSyncEngine, startSyncRuntime } from '../sync/runtime'
@@ -174,9 +175,7 @@ export async function checkSyncIntegrity(): Promise<void> {
 }
 
 function emitVaultRecoveryNeededToWindows(event: VaultRecoveryNeededEvent): void {
-  for (const win of BrowserWindow.getAllWindows()) {
-    win.webContents.send(EVENT_CHANNELS.VAULT_RECOVERY_NEEDED, event)
-  }
+  broadcastToAllWindows(EVENT_CHANNELS.VAULT_RECOVERY_NEEDED, event)
 }
 
 async function cleanupLocalSyncState(): Promise<void> {
diff --git a/apps/desktop/src/main/ipc/tags-handlers.test.ts b/apps/desktop/src/main/ipc/tags-handlers.test.ts
index 18c38766b..cf47d826b 100644
--- a/apps/desktop/src/main/ipc/tags-handlers.test.ts
+++ b/apps/desktop/src/main/ipc/tags-handlers.test.ts
@@ -41,7 +41,9 @@ vi.mock('electron', () => ({
     })
   },
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: mockSend } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: mockSend } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/ipc/tags-handlers.ts b/apps/desktop/src/main/ipc/tags-handlers.ts
index 86bead3bd..7cdcdf8eb 100644
--- a/apps/desktop/src/main/ipc/tags-handlers.ts
+++ b/apps/desktop/src/main/ipc/tags-handlers.ts
@@ -6,7 +6,7 @@
  */
 
 import { readFile } from 'fs/promises'
-import { ipcMain, BrowserWindow } from 'electron'
+import { ipcMain } from 'electron'
 import { eq } from 'drizzle-orm'
 import { TagsChannels } from '@memry/contracts/ipc-channels'
 import {
@@ -63,6 +63,7 @@ import {
   type TagAssignment
 } from '../tags/store'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { toAbsolutePath } from '../vault/notes'
 import { parseNote, serializeParsedNote } from '../vault/frontmatter'
 import { atomicWrite } from '../vault/file-ops'
@@ -84,9 +85,7 @@ const log = createLogger('TagsHandlers')
  * Emit tag event to all windows
  */
 function emitTagEvent(channel: string, data: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, data)
-  })
+  broadcastToAllWindows(channel, data)
 }
 
 /**
diff --git a/apps/desktop/src/main/lib/window-broadcast.ts b/apps/desktop/src/main/lib/window-broadcast.ts
index eb7c68b73..8d7551e1a 100644
--- a/apps/desktop/src/main/lib/window-broadcast.ts
+++ b/apps/desktop/src/main/lib/window-broadcast.ts
@@ -9,7 +9,7 @@ import { BrowserWindow } from 'electron'
  * handlers), where an unguarded throw rolls back an applied item — so skip
  * destroyed windows, mirroring window-rpc.ts and crdt-provider.ts.
  */
-export function broadcastToAllWindows(channel: string, data: unknown): void {
+export function broadcastToAllWindows(channel: string, data?: unknown): void {
   for (const win of BrowserWindow.getAllWindows()) {
     if (win.isDestroyed()) continue
     if (typeof win.webContents.isDestroyed === 'function' && win.webContents.isDestroyed()) continue
diff --git a/apps/desktop/src/main/sync/crdt-writeback.test.ts b/apps/desktop/src/main/sync/crdt-writeback.test.ts
index 3d3f2e995..a379a8688 100644
--- a/apps/desktop/src/main/sync/crdt-writeback.test.ts
+++ b/apps/desktop/src/main/sync/crdt-writeback.test.ts
@@ -42,7 +42,9 @@ vi.mock('electron', () => ({
   BrowserWindow: {
     getAllWindows: () => [
       {
+        isDestroyed: () => false,
         webContents: {
+          isDestroyed: () => false,
           send: (channel: string, payload: unknown) => mocks.sent.push({ channel, payload })
         }
       }
diff --git a/apps/desktop/src/main/sync/crdt-writeback.ts b/apps/desktop/src/main/sync/crdt-writeback.ts
index fbc21dbb2..94af77087 100644
--- a/apps/desktop/src/main/sync/crdt-writeback.ts
+++ b/apps/desktop/src/main/sync/crdt-writeback.ts
@@ -1,5 +1,6 @@
 import * as Y from 'yjs'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { getCrdtProvider } from './crdt-provider'
 import { yDocToMarkdown } from './blocknote-converter'
 import { readCriticMarkupMarksFromYDoc, serializeCriticMarkup } from '@memry/shared'
@@ -34,7 +35,6 @@ import { createRemindersService, type RemindersServiceHooks } from '@memry/app-c
 import { syncNoteDateReminders, clearNoteDateReminders } from '../notes/note-date-reminders'
 import { deleteFile } from '../vault/file-ops'
 import { NotesChannels, JournalChannels } from '@memry/contracts/ipc-channels'
-import { BrowserWindow } from 'electron'
 import path from 'path'
 import {
   enqueueLocalSyncCreate,
@@ -134,9 +134,7 @@ export function wasRecentNetworkUpdate(noteId: string): boolean {
 }
 
 function emitToRenderer(channel: string, data: unknown): void {
-  for (const win of BrowserWindow.getAllWindows()) {
-    win.webContents.send(channel, data)
-  }
+  broadcastToAllWindows(channel, data)
 }
 
 export function scheduleWriteback(noteId: string, doc: Y.Doc): void {
diff --git a/apps/desktop/src/main/sync/item-handlers/settings-handler.test.ts b/apps/desktop/src/main/sync/item-handlers/settings-handler.test.ts
index 23d42f4b4..ea30569e8 100644
--- a/apps/desktop/src/main/sync/item-handlers/settings-handler.test.ts
+++ b/apps/desktop/src/main/sync/item-handlers/settings-handler.test.ts
@@ -46,7 +46,9 @@ vi.mock('../../store', () => ({
 const mockSend = vi.fn()
 vi.mock('electron', () => ({
   BrowserWindow: {
-    getAllWindows: vi.fn(() => [{ webContents: { send: mockSend } }])
+    getAllWindows: vi.fn(() => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: mockSend } }
+    ])
   }
 }))
 
diff --git a/apps/desktop/src/main/sync/item-handlers/settings-handler.ts b/apps/desktop/src/main/sync/item-handlers/settings-handler.ts
index 2f66fe4b0..044100a36 100644
--- a/apps/desktop/src/main/sync/item-handlers/settings-handler.ts
+++ b/apps/desktop/src/main/sync/item-handlers/settings-handler.ts
@@ -1,4 +1,3 @@
-import { BrowserWindow } from 'electron'
 import { SettingsChannels } from '@memry/contracts/ipc-channels'
 import { SettingsSyncPayloadSchema } from '@memry/contracts/settings-sync'
 import type { SettingsSyncPayload, SyncedSettings } from '@memry/contracts/settings-sync'
@@ -13,6 +12,7 @@ import { getDatabase } from '../../database'
 import { getSetting, setSetting, deleteSetting } from '../../database/queries/settings'
 import { INBOX_REVIEW_LAST_NOTIFIED_KEY } from '../../inbox/review-reminder-constants'
 import { createLogger } from '../../lib/logger'
+import { broadcastToAllWindows } from '../../lib/window-broadcast'
 import type { SyncItemHandler, ApplyContext, ApplyResult, DrizzleDb } from './types'
 
 const log = createLogger('SettingsHandler')
@@ -135,38 +135,26 @@ function propagateMergedSettings(merged: SyncedSettings): void {
 }
 
 function broadcastSettingsChanged(merged: SyncedSettings): void {
-  let windows: Electron.BrowserWindow[]
   try {
-    windows = BrowserWindow.getAllWindows()
-  } catch {
-    return
-  }
-  if (windows.length === 0) return
-
-  if (merged.general) {
-    for (const win of windows) {
-      win.webContents.send(SettingsChannels.events.CHANGED, {
+    if (merged.general) {
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
         key: 'general',
         value: merged.general
       })
     }
-  }
-
-  if (merged.editor) {
-    for (const win of windows) {
-      win.webContents.send(SettingsChannels.events.CHANGED, {
+    if (merged.editor) {
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
         key: 'editor',
         value: merged.editor
       })
     }
-  }
-
-  if (merged.inbox) {
-    for (const win of windows) {
-      win.webContents.send(SettingsChannels.events.CHANGED, {
+    if (merged.inbox) {
+      broadcastToAllWindows(SettingsChannels.events.CHANGED, {
         key: 'inbox',
         value: merged.inbox
       })
     }
+  } catch {
+    return
   }
 }
diff --git a/apps/desktop/src/main/sync/linking-service.test.ts b/apps/desktop/src/main/sync/linking-service.test.ts
index be9b0a0b6..8aacd3d8f 100644
--- a/apps/desktop/src/main/sync/linking-service.test.ts
+++ b/apps/desktop/src/main/sync/linking-service.test.ts
@@ -50,7 +50,9 @@ const {
 
 vi.mock('electron', () => ({
   BrowserWindow: {
-    getAllWindows: () => [{ webContents: { send: mockSend } }]
+    getAllWindows: () => [
+      { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: mockSend } }
+    ]
   }
 }))
 
diff --git a/apps/desktop/src/main/sync/linking-service.ts b/apps/desktop/src/main/sync/linking-service.ts
index 7d8afe8e2..771d618fd 100644
--- a/apps/desktop/src/main/sync/linking-service.ts
+++ b/apps/desktop/src/main/sync/linking-service.ts
@@ -1,6 +1,5 @@
 import os from 'os'
 import sodium from 'libsodium-wrappers-sumo'
-import { BrowserWindow } from 'electron'
 
 import { KEYCHAIN_ENTRIES } from '@memry/contracts/crypto'
 import type {
@@ -35,6 +34,7 @@ import {
   persistImportedGoogleProviderAuth
 } from '../calendar/google/provider-auth-transfer'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 import { getFromServer, postToServer, RateLimitError, SyncServerError } from './http-client'
 import { withRetry } from './retry'
@@ -542,9 +542,7 @@ function emitLinkingFinalized(payload: {
   error?: string
   warning?: string
 }): void {
-  for (const win of BrowserWindow.getAllWindows()) {
-    win.webContents.send('sync:linking-finalized', payload)
-  }
+  broadcastToAllWindows('sync:linking-finalized', payload)
 }
 
 // ============================================================================
diff --git a/apps/desktop/src/main/sync/token-manager.test.ts b/apps/desktop/src/main/sync/token-manager.test.ts
index b18241f91..49cbe8432 100644
--- a/apps/desktop/src/main/sync/token-manager.test.ts
+++ b/apps/desktop/src/main/sync/token-manager.test.ts
@@ -217,7 +217,10 @@ describe('token-manager', () => {
       const { SyncServerError } = await import('./http-client')
       mockPostToServer.mockRejectedValue(new SyncServerError('Unauthorized', 401))
 
-      const mockWin = { webContents: { send: vi.fn() } }
+      const mockWin = {
+        isDestroyed: () => false,
+        webContents: { isDestroyed: () => false, send: vi.fn() }
+      }
       mockGetAllWindows.mockReturnValue([mockWin])
 
       // #when
@@ -281,7 +284,10 @@ describe('token-manager', () => {
         return Promise.resolve(null)
       })
       mockDecodeJwt.mockReturnValue({ exp: nowSeconds() - 100 })
-      const win = { webContents: { send: vi.fn() } }
+      const win = {
+        isDestroyed: () => false,
+        webContents: { isDestroyed: () => false, send: vi.fn() }
+      }
       mockGetAllWindows.mockReturnValue([win])
       return { win }
     }
diff --git a/apps/desktop/src/main/sync/token-manager.ts b/apps/desktop/src/main/sync/token-manager.ts
index 4419e6e43..931383f25 100644
--- a/apps/desktop/src/main/sync/token-manager.ts
+++ b/apps/desktop/src/main/sync/token-manager.ts
@@ -1,4 +1,3 @@
-import { BrowserWindow } from 'electron'
 import { decodeJwt } from 'jose'
 
 import { KEYCHAIN_ENTRIES } from '@memry/contracts/crypto'
@@ -8,6 +7,7 @@ import { RefreshTokenResponseSchema } from '@memry/contracts/auth-api'
 import { storeKey, retrieveKey } from '../crypto'
 import { postToServer, SyncServerError } from './http-client'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 const log = createLogger('TokenManager')
 
@@ -104,10 +104,7 @@ export const cancelTokenRefresh = (): void => {
 
 export const emitSessionExpired = (reason: SessionExpiredReason = 'token_expired'): void => {
   cancelTokenRefresh()
-  const windows = BrowserWindow.getAllWindows()
-  for (const win of windows) {
-    win.webContents.send(SYNC_EVENTS.SESSION_EXPIRED, { reason })
-  }
+  broadcastToAllWindows(SYNC_EVENTS.SESSION_EXPIRED, { reason })
 }
 
 const clearRefreshRejections = (): void => {
diff --git a/apps/desktop/src/main/test-hooks.test.ts b/apps/desktop/src/main/test-hooks.test.ts
index c8dd2efdf..36aa6d6fb 100644
--- a/apps/desktop/src/main/test-hooks.test.ts
+++ b/apps/desktop/src/main/test-hooks.test.ts
@@ -1,7 +1,9 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
 const windowSendMock = vi.fn()
-const browserWindows = [{ webContents: { send: windowSendMock } }]
+const browserWindows = [
+  { isDestroyed: () => false, webContents: { isDestroyed: () => false, send: windowSendMock } }
+]
 const storeGetMock = vi.fn(() => ({ existing: true }))
 const storeSetMock = vi.fn()
 const persistKeysAndRegisterDeviceMock = vi.fn(async () => 'device-1')
diff --git a/apps/desktop/src/main/test-hooks.ts b/apps/desktop/src/main/test-hooks.ts
index db8be0ced..4a0221cb0 100644
--- a/apps/desktop/src/main/test-hooks.ts
+++ b/apps/desktop/src/main/test-hooks.ts
@@ -21,6 +21,7 @@ import {
 import { listCalendarExternalEventsBySource } from './calendar/repositories/calendar-external-events-repository'
 import { calendarEvents } from '@memry/db-schema/schema/calendar-events'
 import { getMainI18n } from './lib/main-i18n'
+import { broadcastToAllWindows } from './lib/window-broadcast'
 import { getOrInitializeLocalVaultKey, VAULT_KEY_VERIFIER_SETTING } from './crypto/vault-key-state'
 import { getOrCreateVaultUuid } from './agent/storage/vault-id'
 import { inboxItems, inboxItemType } from '@memry/db-schema/schema/inbox'
@@ -517,20 +518,18 @@ export function registerTestHooks(): void {
         `)
       }
 
-      BrowserWindow.getAllWindows().forEach((win) => {
-        win.webContents.send(CalendarChannels.events.CHANGED, {
-          entityType: 'calendar_external_event',
-          id: 'calendar-e2e-external'
-        })
-        if (input.overlapMemryTitle) {
-          win.webContents.send(CalendarChannels.events.CHANGED, {
-            entityType: 'calendar_event',
-            id: 'calendar-e2e-memry-overlap'
-          })
-        }
-        win.webContents.send(TasksChannels.events.CREATED, {
-          task: { id: 'calendar-e2e-task' }
+      broadcastToAllWindows(CalendarChannels.events.CHANGED, {
+        entityType: 'calendar_external_event',
+        id: 'calendar-e2e-external'
+      })
+      if (input.overlapMemryTitle) {
+        broadcastToAllWindows(CalendarChannels.events.CHANGED, {
+          entityType: 'calendar_event',
+          id: 'calendar-e2e-memry-overlap'
         })
+      }
+      broadcastToAllWindows(TasksChannels.events.CREATED, {
+        task: { id: 'calendar-e2e-task' }
       })
     },
 
diff --git a/apps/desktop/src/main/vault/index.test.ts b/apps/desktop/src/main/vault/index.test.ts
index 42ee2ea8e..19c68dd2b 100644
--- a/apps/desktop/src/main/vault/index.test.ts
+++ b/apps/desktop/src/main/vault/index.test.ts
@@ -67,7 +67,9 @@ vi.mock('electron', () => ({
   BrowserWindow: {
     getAllWindows: () => [
       {
+        isDestroyed: () => false,
         webContents: {
+          isDestroyed: () => false,
           send: (channel: string, payload: unknown) => mocks.sent.push({ channel, payload })
         }
       }
diff --git a/apps/desktop/src/main/vault/index.ts b/apps/desktop/src/main/vault/index.ts
index 5271b8cf8..41a8d6b61 100644
--- a/apps/desktop/src/main/vault/index.ts
+++ b/apps/desktop/src/main/vault/index.ts
@@ -1,4 +1,4 @@
-import { dialog, BrowserWindow } from 'electron'
+import { dialog } from 'electron'
 import type {
   VaultInfo,
   VaultStatus,
@@ -46,6 +46,7 @@ import {
 import { ensureDefaultTaskProject } from '../database/defaults'
 import { VaultChannels } from '@memry/contracts/ipc-channels'
 import { VaultError, VaultErrorCode } from '../lib/errors'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 import { startWatcher, stopWatcher } from './watcher'
 import { indexVault, rebuildIndex } from './indexer'
 import { createLogger } from '../lib/logger'
@@ -188,9 +189,7 @@ function emitStatusChanged(): void {
   // nothing should react to it while the app is quitting/installing.
   if (isShuttingDown) return
   statusListeners.forEach((listener) => listener(currentStatus))
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send('vault:status-changed', currentStatus)
-  })
+  broadcastToAllWindows('vault:status-changed', currentStatus)
 }
 
 /**
@@ -198,9 +197,7 @@ function emitStatusChanged(): void {
  */
 export function emitIndexProgress(progress: number): void {
   updateStatus({ indexProgress: progress })
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send('vault:index-progress', progress)
-  })
+  broadcastToAllWindows('vault:index-progress', progress)
 }
 
 /**
@@ -208,9 +205,7 @@ export function emitIndexProgress(progress: number): void {
  */
 export function emitVaultError(error: string): void {
   updateStatus({ error })
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send('vault:error', error)
-  })
+  broadcastToAllWindows('vault:error', error)
 }
 
 /**
@@ -227,9 +222,7 @@ export interface IndexRecoveredEvent {
  * Sent after automatic recovery from corrupt or missing index.
  */
 export function emitIndexRecovered(event: IndexRecoveredEvent): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(VaultChannels.events.INDEX_RECOVERED, event)
-  })
+  broadcastToAllWindows(VaultChannels.events.INDEX_RECOVERED, event)
 }
 
 /**
diff --git a/apps/desktop/src/main/vault/notes-io.ts b/apps/desktop/src/main/vault/notes-io.ts
index e027b71ba..ee08cf5ae 100644
--- a/apps/desktop/src/main/vault/notes-io.ts
+++ b/apps/desktop/src/main/vault/notes-io.ts
@@ -7,10 +7,10 @@
  */
 
 import path from 'path'
-import { BrowserWindow } from 'electron'
 import { getStatus, getConfig } from './index'
 import { normalizeRelativePath } from '../lib/paths'
 import { VaultError, VaultErrorCode } from '../lib/errors'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 // ============================================================================
 // Helpers
@@ -49,7 +49,5 @@ export function toRelativePath(absolutePath: string): string {
 // ============================================================================
 
 export function emitNoteEvent(channel: string, payload: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, payload)
-  })
+  broadcastToAllWindows(channel, payload)
 }
diff --git a/apps/desktop/src/main/vault/notes.test.ts b/apps/desktop/src/main/vault/notes.test.ts
index 960c08833..fcc86257c 100644
--- a/apps/desktop/src/main/vault/notes.test.ts
+++ b/apps/desktop/src/main/vault/notes.test.ts
@@ -21,8 +21,8 @@ import * as projections from '../projections'
 
 // Mock electron (must be at module level)
 vi.mock('electron', () => {
-  const mockWebContents = { send: vi.fn() }
-  const mockWindow = { webContents: mockWebContents }
+  const mockWebContents = { isDestroyed: () => false, send: vi.fn() }
+  const mockWindow = { isDestroyed: () => false, webContents: mockWebContents }
 
   return {
     BrowserWindow: {
@@ -238,7 +238,10 @@ describe('notes operations', () => {
       const { BrowserWindow } = await import('electron')
       const mockSend = vi.fn()
       vi.mocked(BrowserWindow.getAllWindows).mockReturnValue([
-        { webContents: { send: mockSend } } as never
+        {
+          isDestroyed: () => false,
+          webContents: { isDestroyed: () => false, send: mockSend }
+        } as never
       ])
 
       await notes.createNote({
@@ -523,7 +526,10 @@ describe('notes operations', () => {
       const { BrowserWindow } = await import('electron')
       const mockSend = vi.fn()
       vi.mocked(BrowserWindow.getAllWindows).mockReturnValue([
-        { webContents: { send: mockSend } } as never
+        {
+          isDestroyed: () => false,
+          webContents: { isDestroyed: () => false, send: mockSend }
+        } as never
       ])
 
       const created = await notes.createNote({
@@ -726,7 +732,10 @@ describe('notes operations', () => {
       const { BrowserWindow } = await import('electron')
       const mockSend = vi.fn()
       vi.mocked(BrowserWindow.getAllWindows).mockReturnValue([
-        { webContents: { send: mockSend } } as never
+        {
+          isDestroyed: () => false,
+          webContents: { isDestroyed: () => false, send: mockSend }
+        } as never
       ])
 
       const created = await notes.createNote({
@@ -879,7 +888,10 @@ describe('notes operations', () => {
       const { BrowserWindow } = await import('electron')
       const mockSend = vi.fn()
       vi.mocked(BrowserWindow.getAllWindows).mockReturnValue([
-        { webContents: { send: mockSend } } as never
+        {
+          isDestroyed: () => false,
+          webContents: { isDestroyed: () => false, send: mockSend }
+        } as never
       ])
 
       const created = await notes.createNote({
@@ -982,7 +994,10 @@ describe('notes operations', () => {
       const { BrowserWindow } = await import('electron')
       const mockSend = vi.fn()
       vi.mocked(BrowserWindow.getAllWindows).mockReturnValue([
-        { webContents: { send: mockSend } } as never
+        {
+          isDestroyed: () => false,
+          webContents: { isDestroyed: () => false, send: mockSend }
+        } as never
       ])
 
       const created = await notes.createNote({
diff --git a/apps/desktop/src/main/vault/rename-tracker.ts b/apps/desktop/src/main/vault/rename-tracker.ts
index fcc7835cc..283c4e212 100644
--- a/apps/desktop/src/main/vault/rename-tracker.ts
+++ b/apps/desktop/src/main/vault/rename-tracker.ts
@@ -11,10 +11,10 @@
  */
 
 import path from 'path'
-import { BrowserWindow } from 'electron'
 import { NotesChannels } from '@memry/contracts/ipc-channels'
 import type { NoteRenamedEvent } from '@memry/contracts/notes-api'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 const logger = createLogger('RenameTracker')
 
@@ -77,11 +77,9 @@ export function unregisterRenameSyncCallback(): void {
  * Emit note renamed event to all renderer windows.
  */
 function emitNoteRenamed(event: NoteRenamedEvent): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(NotesChannels.events.RENAMED, {
-      ...event,
-      source: 'external'
-    })
+  broadcastToAllWindows(NotesChannels.events.RENAMED, {
+    ...event,
+    source: 'external'
   })
 }
 
diff --git a/apps/desktop/src/main/vault/templates.ts b/apps/desktop/src/main/vault/templates.ts
index cf1f30cd9..841902ea1 100644
--- a/apps/desktop/src/main/vault/templates.ts
+++ b/apps/desktop/src/main/vault/templates.ts
@@ -8,7 +8,6 @@
 import path from 'path'
 import fs from 'fs/promises'
 import { existsSync, mkdirSync } from 'fs'
-import { BrowserWindow } from 'electron'
 import matter from 'gray-matter'
 import { getStatus } from './index'
 import { getMemryDir } from './init'
@@ -23,6 +22,7 @@ import type {
   TemplateProperty
 } from '@memry/contracts/templates-api'
 import { createLogger } from '../lib/logger'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 const logger = createLogger('Templates')
 
@@ -330,9 +330,7 @@ async function seedBuiltInTemplates(): Promise<void> {
  * Emit template event to all windows.
  */
 function emitTemplateEvent(channel: string, payload: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, payload)
-  })
+  broadcastToAllWindows(channel, payload)
 }
 
 /**
diff --git a/apps/desktop/src/main/vault/watcher.ts b/apps/desktop/src/main/vault/watcher.ts
index a6bbd1764..56f31c95c 100644
--- a/apps/desktop/src/main/vault/watcher.ts
+++ b/apps/desktop/src/main/vault/watcher.ts
@@ -11,7 +11,6 @@ import path from 'path'
 import fs from 'fs/promises'
 import chokidar from 'chokidar'
 import type { FSWatcher } from 'chokidar'
-import { BrowserWindow } from 'electron'
 import { getConfig } from './index'
 import { parseNote, generateContentHash, extractProperties } from './frontmatter'
 import { safeRead } from './file-ops'
@@ -46,6 +45,7 @@ import {
 } from '../journal/runtime-effects'
 import { syncNoteCreate, syncNoteDelete, syncNoteUpdate } from '../notes/runtime-effects'
 import { normalizeRelativePath } from '../lib/paths'
+import { broadcastToAllWindows } from '../lib/window-broadcast'
 
 const logger = createLogger('Watcher')
 
@@ -112,9 +112,7 @@ function createPathDebouncer(
  * Emit event to all renderer windows.
  */
 function emitEvent(channel: string, payload: unknown): void {
-  BrowserWindow.getAllWindows().forEach((win) => {
-    win.webContents.send(channel, payload)
-  })
+  broadcastToAllWindows(channel, payload)
 }
 
 /**
diff --git a/apps/docs/src/architecture/ipc.md b/apps/docs/src/architecture/ipc.md
index dd9a94744..daac6b56d 100644
--- a/apps/docs/src/architecture/ipc.md
+++ b/apps/docs/src/architecture/ipc.md
@@ -83,4 +83,17 @@ log.info('created note', { id })
 
 ## Main → Renderer Broadcasts
 
-Main-process code that fans an event out to every open window — sync status, task and calendar change events, inbox capture/filing/snooze/transcription events, search and embedding progress, updater state, reminders, agent events, and FTS rebuild progress — goes through `broadcastToAllWindows(channel, data)` in `src/main/lib/window-broadcast.ts`. The helper skips destroyed windows: short-lived windows (splash, quick capture, print/export) can still appear in `BrowserWindow.getAllWindows()` after destruction, and an unguarded `webContents.send()` throws — inside a sync item handler that throw escapes `ctx.emit` within the item's DB transaction and rolls it back. Use the helper instead of hand-rolling a `getAllWindows()` loop.
+Main-process code that fans an event out to every open window goes through `broadcastToAllWindows(channel, data?)` in `src/main/lib/window-broadcast.ts`. The helper skips destroyed windows: short-lived windows (splash, quick capture, print/export) can still appear in `BrowserWindow.getAllWindows()` after destruction, and an unguarded `webContents.send()` throws — inside a sync item handler that throw escapes `ctx.emit` within the item's DB transaction and rolls it back. Use the helper instead of hand-rolling a `getAllWindows()` loop.
+
+```ts
+import { broadcastToAllWindows } from '../lib/window-broadcast'
+
+broadcastToAllWindows(SettingsChannels.events.CHANGED, { key, value })
+broadcastToAllWindows('quick-capture:open') // payload is optional
+```
+
+Every fan-out site in main uses it: sync status, session expiry, OAuth and device pairing events, settings changes (local writes and merged remote settings), attachment upload/download progress, vault status, index progress and index recovery, watcher and note-rename events, import progress, template events, inbox capture/filing/snooze/transcription events, search and embedding progress, updater state, reminders, agent events, FTS rebuild progress, and calendar, task, tag, bookmark, saved-filter, journal, canvas, locale, and AI inline events.
+
+The helper is for fan-out only. Code that targets one specific window — a `find()` / `filter()` lookup, `getAllWindows()[0]`, or `BrowserWindow.fromWebContents()` — still uses `BrowserWindow` directly.
+
+Main-process tests that mock `electron` must give each mocked window an `isDestroyed()` that returns `false`, and the same on its `webContents`; otherwise the guard filters the window out and the broadcast assertion never fires.