diff --git a/apps/desktop/electron/main.ts b/apps/desktop/electron/main.ts
index b24decc00815d..b67e8b69f3a7e 100644
--- a/apps/desktop/electron/main.ts
+++ b/apps/desktop/electron/main.ts
@@ -20,6 +20,7 @@ import {
   nativeTheme,
   Notification,
   powerMonitor,
+  powerSaveBlocker,
   protocol,
   safeStorage,
   screen,
@@ -105,6 +106,7 @@ import {
 import { createLinkTitleWindow, guardLinkTitleSession, readLinkTitleWindowTitle } from './link-title-window'
 import { ensureMainWindow } from './main-window-lifecycle'
 import { serializeJsonBody, setJsonRequestHeaders } from './oauth-net-request'
+import { createKeepAwake } from './power-save'
 import { decideProfileDeleteAction, profileNameFromDeleteRequest, resolveRouteProfile } from './profile-delete-routing'
 import {
   buildSessionWindowUrl,
@@ -8643,6 +8645,33 @@ ipcMain.on('hermes:translucency', (_event, payload) => {
   }
 })
 
+// Keep-awake: hold the machine awake for long/overnight runs. Main owns the one
+// blocker and its persisted state so a cold launch restores it (applied on
+// ready — powerSaveBlocker needs the app ready). The renderer toggles it from
+// Settings → Advanced over IPC. See store/keep-awake.
+const KEEP_AWAKE_CONFIG_PATH = path.join(app.getPath('userData'), 'keep-awake.json')
+const keepAwake = createKeepAwake(powerSaveBlocker)
+
+function readPersistedKeepAwake() {
+  try {
+    return JSON.parse(fs.readFileSync(KEEP_AWAKE_CONFIG_PATH, 'utf8')).on === true
+  } catch {
+    return false
+  }
+}
+
+ipcMain.on('hermes:keep-awake', (_event, on) => {
+  const enabled = Boolean(on)
+  keepAwake.set(enabled)
+
+  try {
+    fs.mkdirSync(path.dirname(KEEP_AWAKE_CONFIG_PATH), { recursive: true })
+    fs.writeFileSync(KEEP_AWAKE_CONFIG_PATH, JSON.stringify({ on: enabled }, null, 2), 'utf8')
+  } catch (error) {
+    rememberLog(`[keep-awake] write failed: ${error.message}`)
+  }
+})
+
 ipcMain.handle('hermes:openExternal', (_event, url) => {
   if (!openExternalUrl(url)) {
     throw new Error('Invalid external URL')
@@ -9643,6 +9672,7 @@ app.whenReady().then(() => {
   ensureWslWindowsFonts()
   configureSpellChecker()
   registerPowerResumeListeners()
+  keepAwake.set(readPersistedKeepAwake())
   createWindow()
 
   // Win/Linux cold start: the launching hermes:// URL is in our own argv.
diff --git a/apps/desktop/electron/power-save.test.ts b/apps/desktop/electron/power-save.test.ts
new file mode 100644
index 0000000000000..97725e0ed019e
--- /dev/null
+++ b/apps/desktop/electron/power-save.test.ts
@@ -0,0 +1,58 @@
+import { describe, expect, it, vi } from 'vitest'
+
+import { createKeepAwake, type PowerSaveBlockerLike } from './power-save'
+
+function fakeBlocker() {
+  let next = 1
+  const started = new Set<number>()
+
+  const blocker: PowerSaveBlockerLike = {
+    isStarted: id => started.has(id),
+    start: vi.fn(() => {
+      const id = next++
+      started.add(id)
+
+      return id
+    }),
+    stop: vi.fn(id => void started.delete(id))
+  }
+
+  return { blocker, started }
+}
+
+describe('createKeepAwake', () => {
+  it('starts once, is idempotent, and stops', () => {
+    const { blocker } = fakeBlocker()
+    const keepAwake = createKeepAwake(blocker)
+
+    expect(keepAwake.isActive()).toBe(false)
+    expect(keepAwake.set(true)).toBe(true)
+    keepAwake.set(true) // idempotent — no second blocker
+    expect(blocker.start).toHaveBeenCalledTimes(1)
+    expect(blocker.start).toHaveBeenCalledWith('prevent-app-suspension')
+
+    expect(keepAwake.set(false)).toBe(false)
+    keepAwake.set(false)
+    expect(blocker.stop).toHaveBeenCalledTimes(1)
+  })
+
+  it('re-arms after the OS dropped the blocker', () => {
+    const { blocker, started } = fakeBlocker()
+    const keepAwake = createKeepAwake(blocker)
+
+    keepAwake.set(true)
+    started.clear() // system released it out from under us
+    expect(keepAwake.isActive()).toBe(false)
+
+    keepAwake.set(true)
+    expect(blocker.start).toHaveBeenCalledTimes(2)
+    expect(keepAwake.isActive()).toBe(true)
+  })
+
+  it('honors a custom blocker type', () => {
+    const { blocker } = fakeBlocker()
+    createKeepAwake(blocker, 'prevent-display-sleep').set(true)
+
+    expect(blocker.start).toHaveBeenCalledWith('prevent-display-sleep')
+  })
+})
diff --git a/apps/desktop/electron/power-save.ts b/apps/desktop/electron/power-save.ts
new file mode 100644
index 0000000000000..0939de99d80cc
--- /dev/null
+++ b/apps/desktop/electron/power-save.ts
@@ -0,0 +1,50 @@
+/**
+ * Keep-awake — hold a single machine-global power-save blocker.
+ *
+ * `prevent-app-suspension` stops the system from sleeping (long overnight
+ * agent runs keep going) while still letting the display dim. The renderer
+ * owns the preference (persisted in localStorage) and mirrors it here over
+ * IPC; the main process owns the one native blocker, same authority split as
+ * translucency/zoom. Electron auto-releases the blocker on quit.
+ */
+
+export type KeepAwakeType = 'prevent-app-suspension' | 'prevent-display-sleep'
+
+/** The slice of Electron's `powerSaveBlocker` we use (injected for testing). */
+export interface PowerSaveBlockerLike {
+  start(type: KeepAwakeType): number
+  stop(id: number): void
+  isStarted(id: number): boolean
+}
+
+export interface KeepAwake {
+  /** Turn the blocker on/off (idempotent). Returns the resulting state. */
+  set(on: boolean): boolean
+  isActive(): boolean
+}
+
+export function createKeepAwake(
+  blocker: PowerSaveBlockerLike,
+  type: KeepAwakeType = 'prevent-app-suspension'
+): KeepAwake {
+  let id: null | number = null
+
+  const isActive = () => id !== null && blocker.isStarted(id)
+
+  return {
+    isActive,
+    set(on) {
+      if (on && !isActive()) {
+        id = blocker.start(type)
+      } else if (!on && id !== null) {
+        if (blocker.isStarted(id)) {
+          blocker.stop(id)
+        }
+
+        id = null
+      }
+
+      return isActive()
+    }
+  }
+}
diff --git a/apps/desktop/electron/preload.ts b/apps/desktop/electron/preload.ts
index 952fdfdc8dad0..732d13a53668b 100644
--- a/apps/desktop/electron/preload.ts
+++ b/apps/desktop/electron/preload.ts
@@ -79,6 +79,7 @@ contextBridge.exposeInMainWorld('hermesDesktop', {
   setTitleBarTheme: payload => ipcRenderer.send('hermes:titlebar-theme', payload),
   setNativeTheme: mode => ipcRenderer.send('hermes:native-theme', mode),
   setTranslucency: payload => ipcRenderer.send('hermes:translucency', payload),
+  setKeepAwake: on => ipcRenderer.send('hermes:keep-awake', on),
   setPreviewShortcutActive: active => ipcRenderer.send('hermes:previewShortcutActive', Boolean(active)),
   openExternal: url => ipcRenderer.invoke('hermes:openExternal', url),
   openPreviewInBrowser: url => ipcRenderer.invoke('hermes:openPreviewInBrowser', url),
diff --git a/apps/desktop/src/app/settings/config-settings.tsx b/apps/desktop/src/app/settings/config-settings.tsx
index 2674fa1910392..50708ef4b88a1 100644
--- a/apps/desktop/src/app/settings/config-settings.tsx
+++ b/apps/desktop/src/app/settings/config-settings.tsx
@@ -1,3 +1,4 @@
+import { useStore } from '@nanostores/react'
 import { useQuery } from '@tanstack/react-query'
 import type { ChangeEvent } from 'react'
 import { useEffect, useMemo, useRef, useState } from 'react'
@@ -6,6 +7,7 @@ import { useSearchParams } from 'react-router-dom'
 import { Button } from '@/components/ui/button'
 import { getElevenLabsVoices, getHermesConfigSchema, saveHermesConfig } from '@/hermes'
 import { useI18n } from '@/i18n'
+import { $keepAwake, setKeepAwake } from '@/store/keep-awake'
 import { notify, notifyError } from '@/store/notifications'
 import type { ConfigFieldSchema, HermesConfigRecord } from '@/types/hermes'
 
@@ -18,7 +20,7 @@ import { enumOptionsFor, getNested, isExternalMemoryProvider, sectionFieldEntrie
 import { MemoryConnect } from './memory/connect'
 import { ProviderConfigPanel } from './memory/provider-config-panel'
 import { ModelSettings, ModelSettingsSkeleton } from './model-settings'
-import { EmptyState, LoadingState, SettingsContent } from './primitives'
+import { EmptyState, LoadingState, SettingsContent, ToggleRow } from './primitives'
 
 // On the Voice page, only surface the sub-fields of the *selected* TTS/STT
 // provider — otherwise every provider's options render at once (the "totally
@@ -53,6 +55,7 @@ export function ConfigSettings({
 }) {
   const { t } = useI18n()
   const c = t.settings.config
+  const keepAwake = useStore($keepAwake)
   // The editable draft is local (debounced autosave watches it), but it's seeded
   // from — and saved back through — the shared config cache, so edits are visible
   // in the MCP/model surfaces and reopening the page doesn't reload-flash.
@@ -269,6 +272,11 @@ export function ConfigSettings({
           <ModelSettings onMainModelChanged={onMainModelChanged} />
         </div>
       )}
+      {/* Device-local desktop pref (not config.yaml) — lives here since keeping
+          the machine awake is a power-user knob. */}
+      {activeSectionId === 'advanced' && (
+        <ToggleRow checked={keepAwake} description={c.keepAwakeDesc} label={c.keepAwakeTitle} onChange={setKeepAwake} />
+      )}
       {visibleFields.length === 0 ? (
         <EmptyState description={c.emptyDesc} title={c.emptyTitle} />
       ) : (
diff --git a/apps/desktop/src/app/settings/memory/provider-config-panel.tsx b/apps/desktop/src/app/settings/memory/provider-config-panel.tsx
index ab7b29da9884f..aa0c5ffd86616 100644
--- a/apps/desktop/src/app/settings/memory/provider-config-panel.tsx
+++ b/apps/desktop/src/app/settings/memory/provider-config-panel.tsx
@@ -1,5 +1,6 @@
 import { useCallback, useEffect, useState } from 'react'
 
+import { PageLoader } from '@/components/page-loader'
 import { Button } from '@/components/ui/button'
 import { DisclosureCaret } from '@/components/ui/disclosure-caret'
 import { getMemoryProviderConfig, saveMemoryProviderConfig } from '@/hermes'
@@ -7,7 +8,7 @@ import { SlidersHorizontal } from '@/lib/icons'
 import { notifyError } from '@/store/notifications'
 import type { MemoryProviderConfig, MemoryProviderField } from '@/types/hermes'
 
-import { ListRow, LoadingState, Pill } from '../primitives'
+import { ListRow, Pill } from '../primitives'
 
 import { FieldControl, FieldTitle } from './field-control'
 import { ProviderConfigModal } from './provider-config-modal'
@@ -95,7 +96,7 @@ export function ProviderConfigPanel({ provider }: { provider: string }) {
       )
     }
 
-    return <LoadingState label="Loading memory provider settings..." />
+    return <PageLoader className="min-h-24" label="Loading memory provider settings..." />
   }
 
   const inlineFields = config.fields.filter(field => field.inline)
diff --git a/apps/desktop/src/app/settings/notifications-settings.tsx b/apps/desktop/src/app/settings/notifications-settings.tsx
index efb0bf662f6e9..b2810f691fed9 100644
--- a/apps/desktop/src/app/settings/notifications-settings.tsx
+++ b/apps/desktop/src/app/settings/notifications-settings.tsx
@@ -3,7 +3,6 @@ import type { ReactNode } from 'react'
 
 import { Button } from '@/components/ui/button'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
-import { Switch } from '@/components/ui/switch'
 import { useI18n } from '@/i18n'
 import { COMPLETION_SOUND_VARIANTS, previewCompletionSound } from '@/lib/completion-sound'
 import { triggerHaptic } from '@/lib/haptics'
@@ -20,7 +19,7 @@ import {
 import { notify } from '@/store/notifications'
 
 import { CONTROL_TEXT } from './constants'
-import { ListRow, SectionHeading, SettingsContent } from './primitives'
+import { ListRow, SectionHeading, SettingsContent, ToggleRow } from './primitives'
 
 const CAPTION = 'text-[length:var(--conversation-caption-font-size)] text-(--ui-text-tertiary)'
 
@@ -28,32 +27,6 @@ function Caption({ children, className }: { children: ReactNode; className?: str
   return <p className={cn(CAPTION, className)}>{children}</p>
 }
 
-function ToggleRow(props: {
-  checked: boolean
-  description: string
-  disabled?: boolean
-  label: string
-  onChange: (on: boolean) => void
-}) {
-  return (
-    <ListRow
-      action={
-        <Switch
-          aria-label={props.label}
-          checked={props.checked}
-          disabled={props.disabled}
-          onCheckedChange={on => {
-            triggerHaptic('selection')
-            props.onChange(on)
-          }}
-        />
-      }
-      description={props.description}
-      title={props.label}
-    />
-  )
-}
-
 export function NotificationsSettings() {
   const { t } = useI18n()
   const prefs = useStore($nativeNotifyPrefs)
diff --git a/apps/desktop/src/app/settings/primitives.tsx b/apps/desktop/src/app/settings/primitives.tsx
index 2d9d1906ef5ff..4e55a2f9f4b97 100644
--- a/apps/desktop/src/app/settings/primitives.tsx
+++ b/apps/desktop/src/app/settings/primitives.tsx
@@ -3,6 +3,8 @@ import type { ReactNode } from 'react'
 import { PageLoader } from '@/components/page-loader'
 import { Badge } from '@/components/ui/badge'
 import { Button } from '@/components/ui/button'
+import { Switch } from '@/components/ui/switch'
+import { triggerHaptic } from '@/lib/haptics'
 import type { IconComponent } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 
@@ -108,8 +110,50 @@ export function ListRow({
   )
 }
 
+// A labelled on/off row — the canonical device-pref switch (haptic baked in).
+export function ToggleRow({
+  checked,
+  description,
+  disabled,
+  label,
+  onChange
+}: {
+  checked: boolean
+  description?: string
+  disabled?: boolean
+  label: string
+  onChange: (on: boolean) => void
+}) {
+  return (
+    <ListRow
+      action={
+        <Switch
+          aria-label={label}
+          checked={checked}
+          disabled={disabled}
+          onCheckedChange={on => {
+            triggerHaptic('selection')
+            onChange(on)
+          }}
+        />
+      }
+      description={description}
+      title={label}
+    />
+  )
+}
+
+// The settings panels render this as the sole child of the top-padded
+// OverlayMain (pt = titlebar + 1rem, no bottom pad — see settings/index.tsx).
+// Cancel that top pad so the loader centers in the whole card, not just the
+// band beneath it. Inline loaders (mid-panel) should use <PageLoader> directly.
 export function LoadingState({ label }: { label: string }) {
-  return <PageLoader label={label} />
+  return (
+    <PageLoader
+      className="-mt-[calc(var(--titlebar-height)+1rem)] h-[calc(100%+var(--titlebar-height)+1rem)]"
+      label={label}
+    />
+  )
 }
 
 // Canonical implementation lives in components/ui; re-exported so the many
diff --git a/apps/desktop/src/global.d.ts b/apps/desktop/src/global.d.ts
index a37091ceeb49c..9202c28e7fc62 100644
--- a/apps/desktop/src/global.d.ts
+++ b/apps/desktop/src/global.d.ts
@@ -88,6 +88,7 @@ declare global {
       setTitleBarTheme?: (payload: HermesTitleBarTheme) => void
       setNativeTheme?: (mode: 'dark' | 'light' | 'system') => void
       setTranslucency?: (payload: { intensity: number }) => void
+      setKeepAwake?: (on: boolean) => void
       setPreviewShortcutActive?: (active: boolean) => void
       openExternal: (url: string) => Promise<void>
       openPreviewInBrowser?: (url: string) => Promise<void>
diff --git a/apps/desktop/src/i18n/en.ts b/apps/desktop/src/i18n/en.ts
index a0e79037f8752..a17ecbb3bd60b 100644
--- a/apps/desktop/src/i18n/en.ts
+++ b/apps/desktop/src/i18n/en.ts
@@ -523,7 +523,9 @@ export const en: Translations = {
       failedLoad: 'Settings failed to load',
       autosaveFailed: 'Autosave failed',
       imported: 'Config imported',
-      invalidJson: 'Invalid config JSON'
+      invalidJson: 'Invalid config JSON',
+      keepAwakeTitle: 'Keep computer awake',
+      keepAwakeDesc: 'Stop this machine from sleeping so long or overnight runs keep going. The display can still dim.'
     },
     credentials: {
       pasteKey: 'Paste key',
diff --git a/apps/desktop/src/i18n/ja.ts b/apps/desktop/src/i18n/ja.ts
index ed902c8ee8b7a..3ade882c6ab87 100644
--- a/apps/desktop/src/i18n/ja.ts
+++ b/apps/desktop/src/i18n/ja.ts
@@ -621,7 +621,9 @@ export const ja = defineLocale({
       failedLoad: '設定の読み込みに失敗しました',
       autosaveFailed: '自動保存に失敗しました',
       imported: '設定をインポートしました',
-      invalidJson: '設定 JSON が無効です'
+      invalidJson: '設定 JSON が無効です',
+      keepAwakeTitle: 'コンピューターをスリープさせない',
+      keepAwakeDesc: '本体のスリープを防ぎ、長時間や夜通しの実行を継続します。画面は暗転できます。'
     },
     credentials: {
       pasteKey: 'キーを貼り付け',
diff --git a/apps/desktop/src/i18n/types.ts b/apps/desktop/src/i18n/types.ts
index ae2ec69bcdac1..25a9f67e21980 100644
--- a/apps/desktop/src/i18n/types.ts
+++ b/apps/desktop/src/i18n/types.ts
@@ -435,6 +435,8 @@ export interface Translations {
       autosaveFailed: string
       imported: string
       invalidJson: string
+      keepAwakeTitle: string
+      keepAwakeDesc: string
     }
     credentials: {
       pasteKey: string
diff --git a/apps/desktop/src/i18n/zh-hant.ts b/apps/desktop/src/i18n/zh-hant.ts
index c30818309a426..d061a6d57a796 100644
--- a/apps/desktop/src/i18n/zh-hant.ts
+++ b/apps/desktop/src/i18n/zh-hant.ts
@@ -609,7 +609,9 @@ export const zhHant = defineLocale({
       failedLoad: '設定載入失敗',
       autosaveFailed: '自動儲存失敗',
       imported: '設定已匯入',
-      invalidJson: '設定 JSON 無效'
+      invalidJson: '設定 JSON 無效',
+      keepAwakeTitle: '保持電腦喚醒',
+      keepAwakeDesc: '阻止本機睡眠，讓長時間或整夜執行持續進行。螢幕仍可變暗。'
     },
     credentials: {
       pasteKey: '貼上金鑰',
diff --git a/apps/desktop/src/i18n/zh.ts b/apps/desktop/src/i18n/zh.ts
index 253e01326c617..61d6ff602aab3 100644
--- a/apps/desktop/src/i18n/zh.ts
+++ b/apps/desktop/src/i18n/zh.ts
@@ -720,7 +720,9 @@ export const zh: Translations = {
       failedLoad: '设置加载失败',
       autosaveFailed: '自动保存失败',
       imported: '配置已导入',
-      invalidJson: '配置 JSON 无效'
+      invalidJson: '配置 JSON 无效',
+      keepAwakeTitle: '保持电脑唤醒',
+      keepAwakeDesc: '阻止本机休眠，让长时间或通宵运行继续进行。屏幕仍可变暗。'
     },
     credentials: {
       pasteKey: '粘贴密钥',
diff --git a/apps/desktop/src/store/keep-awake.test.ts b/apps/desktop/src/store/keep-awake.test.ts
new file mode 100644
index 0000000000000..4807e436ae4c9
--- /dev/null
+++ b/apps/desktop/src/store/keep-awake.test.ts
@@ -0,0 +1,33 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { storedBoolean } from '@/lib/storage'
+
+import { $keepAwake, setKeepAwake } from './keep-awake'
+
+const KEY = 'hermes.desktop.keepAwake.v1'
+const desktopWindow = window as unknown as { hermesDesktop?: Window['hermesDesktop'] }
+const initialHermesDesktop = desktopWindow.hermesDesktop
+const setKeepAwakeBridge = vi.fn()
+
+beforeEach(() => {
+  desktopWindow.hermesDesktop = { setKeepAwake: setKeepAwakeBridge } as unknown as Window['hermesDesktop']
+  setKeepAwake(false)
+  setKeepAwakeBridge.mockClear()
+})
+
+afterEach(() => {
+  desktopWindow.hermesDesktop = initialHermesDesktop
+})
+
+describe('keep-awake store', () => {
+  it('persists the pref and mirrors it to the main process', () => {
+    setKeepAwake(true)
+    expect($keepAwake.get()).toBe(true)
+    expect(storedBoolean(KEY, false)).toBe(true)
+    expect(setKeepAwakeBridge).toHaveBeenLastCalledWith(true)
+
+    setKeepAwake(false)
+    expect(storedBoolean(KEY, true)).toBe(false)
+    expect(setKeepAwakeBridge).toHaveBeenLastCalledWith(false)
+  })
+})
diff --git a/apps/desktop/src/store/keep-awake.ts b/apps/desktop/src/store/keep-awake.ts
new file mode 100644
index 0000000000000..f2d2022391f37
--- /dev/null
+++ b/apps/desktop/src/store/keep-awake.ts
@@ -0,0 +1,29 @@
+/**
+ * Keep-awake — stop the machine sleeping during long, unattended runs.
+ *
+ * A device-local preference (each computer keeps its own), off by default. This
+ * atom backs the Settings → Advanced toggle and mirrors changes to the main
+ * process, which owns the real power-save blocker AND its own persisted copy —
+ * so a cold launch restores the blocker without the renderer visiting Settings
+ * (see electron/main.ts + electron/power-save.ts). Linux/web without the bridge
+ * just no-op.
+ */
+
+import { atom } from 'nanostores'
+
+import { persistBoolean, storedBoolean } from '@/lib/storage'
+
+const KEY = 'hermes.desktop.keepAwake.v1'
+
+export const $keepAwake = atom<boolean>(typeof window === 'undefined' ? false : storedBoolean(KEY, false))
+
+export function setKeepAwake(on: boolean): void {
+  $keepAwake.set(on)
+}
+
+if (typeof window !== 'undefined') {
+  $keepAwake.subscribe(on => {
+    persistBoolean(KEY, on)
+    window.hermesDesktop?.setKeepAwake?.(on)
+  })
+}