diff --git a/apps/desktop/src/main/services/text-insert/nut-keyboard-port.ts b/apps/desktop/src/main/services/text-insert/nut-keyboard-port.ts
index 659a1c5..66e6f69 100644
--- a/apps/desktop/src/main/services/text-insert/nut-keyboard-port.ts
+++ b/apps/desktop/src/main/services/text-insert/nut-keyboard-port.ts
@@ -2,6 +2,7 @@
 // 키 입력 시뮬레이션 포트와 nut-js 어댑터.
 // nut-js 는 ESM + 네이티브 모듈이므로 첫 사용 시 lazy dynamic import 한다.
 
+import type { Key as NutKey } from '@nut-tree-fork/nut-js'
 import { getLogger } from '../LoggerService'
 import { D3ROError, ErrorCode } from '@d3ro/core/errors'
 
@@ -15,46 +16,96 @@ export interface KeyboardPort {
   type(text: string): Promise<void>
 }
 
-type NutModule = typeof import('@nut-tree-fork/nut-js')
+/**
+ * nut-js 가 키 이벤트마다 넣는 지연(ms).
+ * nut-js 기본값은 300ms 로, pressKey/releaseKey/글자마다 그만큼 잠든다 — Ctrl 이 300ms 동안
+ * 눌린 채 남아 사용자의 다음 키가 단축키가 되고, 60자 타이핑에 18초가 걸린다.
+ * 앱이 붙여넣기를 처리할 시간은 TextInsertService 가 자기 sleep 으로 따로 준다.
+ */
+export const NUT_KEY_DELAY_MS = 0
 
-interface NutKeyboard {
-  pressKey: NutModule['keyboard']['pressKey']
-  releaseKey: NutModule['keyboard']['releaseKey']
-  type: NutModule['keyboard']['type']
-  Key: NutModule['Key']
+/** nut-js 네이티브 키보드 provider 중 이 어댑터가 쓰는 부분. */
+export interface NutNativeKeyboard {
+  setKeyboardDelay(delay: number): void
+  /** 문자열 전체를 네이티브 호출 한 번으로 타이핑 */
+  type(input: string): Promise<void>
+  /** modifier down → 키 down/up → modifier up 을 네이티브 호출 한 번(keyTap)으로 */
+  click(...keys: NutKey[]): Promise<void>
 }
 
+/**
+ * 이 어댑터가 nut-js 모듈에서 쓰는 부분만 적은 구조 타입.
+ * 실제 모듈이 그대로 맞고, 테스트는 가짜 provider 로 만든 모듈을 넣을 수 있다.
+ */
+export interface NutKeyboardModule {
+  keyboard: { config: { autoDelayMs: number } }
+  providerRegistry: {
+    hasKeyboard(): boolean
+    getKeyboard(): NutNativeKeyboard
+  }
+  Key: Pick<typeof NutKey, 'LeftControl' | 'LeftSuper' | 'V'>
+}
+
+export type NutModuleLoader = () => Promise<NutKeyboardModule>
+
+const loadNutModule: NutModuleLoader = () => import('@nut-tree-fork/nut-js')
+
+/**
+ * nut-js 의 JS 쪽 autoDelay 와 네이티브 keyboardDelay 를 모두 NUT_KEY_DELAY_MS 로 맞춘다.
+ * 네이티브 지연은 키 토글 뒤 메인 스레드를 동기로 막으므로 JS 설정만으로는 부족하다.
+ */
+export function configureNutKeyDelay(nut: NutKeyboardModule, delayMs: number = NUT_KEY_DELAY_MS): void {
+  nut.keyboard.config.autoDelayMs = delayMs
+  if (nut.providerRegistry.hasKeyboard()) {
+    nut.providerRegistry.getKeyboard().setKeyboardDelay(delayMs)
+  }
+}
+
+interface LoadedNut {
+  native: NutNativeKeyboard
+  Key: NutKeyboardModule['Key']
+}
+
+/**
+ * nut-js 네이티브 provider 로 키를 보내는 KeyboardPort 어댑터.
+ * KeyboardClass(pressKey/releaseKey/type)를 거치지 않는다 — 그 경로는 키 이벤트·글자마다
+ * JS setTimeout 을 끼워 넣어, 지연 0 이어도 Windows 타이머 해상도(~15ms)만큼 글자가 늘어진다.
+ */
 export class NutKeyboardPort implements KeyboardPort {
-  private _nutKeyboard: NutKeyboard | null = null
+  private _nut: LoadedNut | null = null
   private _nutLoadPromise: Promise<void> | null = null
 
-  constructor(private readonly _platform: NodeJS.Platform = process.platform) {}
+  constructor(
+    private readonly _platform: NodeJS.Platform = process.platform,
+    private readonly _load: NutModuleLoader = loadNutModule
+  ) {}
 
+  /** 붙여넣기 단축키를 한 번의 코드(chord)로 보내 await 사이에 modifier 가 눌린 채 남지 않게 한다. */
   async paste(): Promise<void> {
     const nut = await this._ensureNut()
     const pasteModKey = this._platform === 'darwin' ? nut.Key.LeftSuper : nut.Key.LeftControl
-    await nut.pressKey(pasteModKey, nut.Key.V)
-    await nut.releaseKey(nut.Key.V, pasteModKey)
+    await nut.native.click(pasteModKey, nut.Key.V)
   }
 
+  /** 텍스트 전체를 네이티브 호출 한 번으로 타이핑한다 (글자 사이 JS 대기 없음). */
   async type(text: string): Promise<void> {
+    if (!text) return
     const nut = await this._ensureNut()
-    await nut.type(text)
+    await nut.native.type(text)
   }
 
-  private async _ensureNut(): Promise<NutKeyboard> {
-    if (this._nutKeyboard) return this._nutKeyboard
+  private async _ensureNut(): Promise<LoadedNut> {
+    if (this._nut) return this._nut
 
     if (!this._nutLoadPromise) {
       this._nutLoadPromise = (async () => {
         try {
-          const nut = await import('@nut-tree-fork/nut-js')
-          this._nutKeyboard = {
-            pressKey: nut.keyboard.pressKey.bind(nut.keyboard),
-            releaseKey: nut.keyboard.releaseKey.bind(nut.keyboard),
-            type: nut.keyboard.type.bind(nut.keyboard),
-            Key: nut.Key
+          const nut = await this._load()
+          if (!nut.providerRegistry.hasKeyboard()) {
+            throw new Error('no native keyboard provider registered')
           }
+          configureNutKeyDelay(nut)
+          this._nut = { native: nut.providerRegistry.getKeyboard(), Key: nut.Key }
           logger.info('nut-js loaded successfully')
         } catch (error) {
           logger.error(`Failed to load nut-js: ${error instanceof Error ? error.message : String(error)}`)
@@ -67,9 +118,9 @@ export class NutKeyboardPort implements KeyboardPort {
     }
 
     await this._nutLoadPromise
-    if (!this._nutKeyboard) {
+    if (!this._nut) {
       throw new D3ROError(ErrorCode.TextInsertKeySimulationFailed, 'nut-js not available')
     }
-    return this._nutKeyboard
+    return this._nut
   }
 }
diff --git a/apps/desktop/tests/main/services/textinsert-redteam-r2-4.test.ts b/apps/desktop/tests/main/services/textinsert-redteam-r2-4.test.ts
new file mode 100644
index 0000000..101de97
--- /dev/null
+++ b/apps/desktop/tests/main/services/textinsert-redteam-r2-4.test.ts
@@ -0,0 +1,240 @@
+// tests/main/services/textinsert-redteam-r2-4.test.ts
+// 회귀: nut-js 기본 autoDelay(300ms)가 그대로 남아 붙여넣기마다 Ctrl 이 ~300ms 눌린 채
+// 유지되고(사용자의 다음 키가 Ctrl 단축키가 됨), 키보드 삽입이 글자당 300ms 걸리던 버그.
+// 실제 nut-js KeyboardClass 를 가짜 네이티브 provider 위에 올려 검증한다 (키는 실제로 눌리지 않는다).
+
+import { describe, it, expect, vi } from 'vitest'
+import { KeyboardClass } from '@nut-tree-fork/nut-js/dist/lib/keyboard.class'
+import { Key } from '@nut-tree-fork/shared'
+import {
+  NutKeyboardPort,
+  NUT_KEY_DELAY_MS,
+  configureNutKeyDelay,
+  type NutKeyboardModule
+} from '../../../src/main/services/text-insert/nut-keyboard-port'
+import { TextInsertService } from '../../../src/main/services/TextInsertService'
+import type { ClipboardImage, ClipboardPort } from '../../../src/main/services/text-insert/clipboard-snapshot'
+import { ErrorCode } from '@d3ro/core/errors'
+
+type ProviderRegistryArg = ConstructorParameters<typeof KeyboardClass>[0]
+
+type NativeEvent =
+  | { kind: 'type'; char: string }
+  | { kind: 'click'; keys: Key[] }
+  | { kind: 'press'; keys: Key[] }
+  | { kind: 'release'; keys: Key[] }
+
+/** libnut 대신 이벤트만 기록하는 가짜 provider registry. */
+class FakeRegistry {
+  events: NativeEvent[] = []
+  nativeDelays: number[] = []
+  private readonly _log = { debug: vi.fn(), info: vi.fn(), error: vi.fn(), warn: vi.fn(), trace: vi.fn() }
+  private readonly _keyboard = {
+    setKeyboardDelay: (delay: number): void => {
+      this.nativeDelays.push(delay)
+    },
+    type: async (char: string): Promise<void> => {
+      this.events.push({ kind: 'type', char })
+    },
+    click: async (...keys: Key[]): Promise<void> => {
+      this.events.push({ kind: 'click', keys })
+    },
+    pressKey: async (...keys: Key[]): Promise<void> => {
+      this.events.push({ kind: 'press', keys })
+    },
+    releaseKey: async (...keys: Key[]): Promise<void> => {
+      this.events.push({ kind: 'release', keys })
+    }
+  }
+
+  hasKeyboard(): boolean {
+    return true
+  }
+  getKeyboard(): typeof this._keyboard {
+    return this._keyboard
+  }
+  getLogProvider(): typeof this._log {
+    return this._log
+  }
+}
+
+function makeNut(): { nut: NutKeyboardModule; registry: FakeRegistry; keyboard: KeyboardClass } {
+  const registry = new FakeRegistry()
+  const keyboard = new KeyboardClass(registry as unknown as ProviderRegistryArg)
+  return { nut: { keyboard, providerRegistry: registry, Key }, registry, keyboard }
+}
+
+async function timed(fn: () => Promise<unknown>): Promise<number> {
+  const start = performance.now()
+  await fn()
+  return performance.now() - start
+}
+
+describe('NutKeyboardPort key delay (redteam r2-4)', () => {
+  it('real nut-js KeyboardClass starts with a 300ms autoDelay (the hazard being fixed)', () => {
+    const { keyboard, registry } = makeNut()
+    expect(keyboard.config.autoDelayMs).toBe(300)
+    expect(registry.nativeDelays).toEqual([300])
+  })
+
+  it('zeroes both the JS autoDelay and the native keyboard delay on load', async () => {
+    const { nut, registry, keyboard } = makeNut()
+    const port = new NutKeyboardPort('win32', async () => nut)
+
+    await port.paste()
+
+    expect(NUT_KEY_DELAY_MS).toBe(0)
+    expect(keyboard.config.autoDelayMs).toBe(0)
+    expect(registry.nativeDelays.at(-1)).toBe(0)
+  })
+
+  it('sends Ctrl+V as a single native chord without holding the modifier across awaits', async () => {
+    const { nut, registry } = makeNut()
+    const port = new NutKeyboardPort('win32', async () => nut)
+
+    const elapsed = await timed(() => port.paste())
+
+    expect(registry.events).toEqual([{ kind: 'click', keys: [Key.LeftControl, Key.V] }])
+    expect(registry.events.some((e) => e.kind === 'press' || e.kind === 'release')).toBe(false)
+    // 수정 전: pressKey·releaseKey 앞에서 각각 300ms → 600ms 이상
+    expect(elapsed).toBeLessThan(150)
+  })
+
+  it('uses the Super (⌘) modifier on macOS', async () => {
+    const { nut, registry } = makeNut()
+    const port = new NutKeyboardPort('darwin', async () => nut)
+
+    await port.paste()
+
+    expect(registry.events).toEqual([{ kind: 'click', keys: [Key.LeftSuper, Key.V] }])
+  })
+
+  it('types a 60-character text without per-character 300ms sleeps', async () => {
+    const { nut, registry } = makeNut()
+    const port = new NutKeyboardPort('win32', async () => nut)
+    const text = '가나다라마바사아자차카타파하 hello world, this is a suggestion!!'.padEnd(60, '.')
+
+    const elapsed = await timed(() => port.type(text))
+
+    // 글자마다 JS sleep 을 끼우는 KeyboardClass.type 대신 네이티브 호출 한 번
+    expect(registry.events).toEqual([{ kind: 'type', char: text }])
+    // 수정 전: 60 × 300ms = 18s
+    expect(elapsed).toBeLessThan(150)
+  })
+
+  it('loads nut-js once and reuses it', async () => {
+    const { nut } = makeNut()
+    const load = vi.fn(async () => nut)
+    const port = new NutKeyboardPort('win32', load)
+
+    await Promise.all([port.paste(), port.type('a'), port.paste()])
+
+    expect(load).toHaveBeenCalledTimes(1)
+  })
+
+  it('does not touch the keyboard for empty text', async () => {
+    const { nut, registry } = makeNut()
+    const load = vi.fn(async () => nut)
+    const port = new NutKeyboardPort('win32', load)
+
+    await port.type('')
+
+    expect(load).not.toHaveBeenCalled()
+    expect(registry.events).toEqual([])
+  })
+
+  it('fails with TextInsertKeySimulationFailed when no native keyboard provider is registered', async () => {
+    const { nut, registry } = makeNut()
+    const port = new NutKeyboardPort('win32', async () => ({
+      ...nut,
+      providerRegistry: { hasKeyboard: () => false, getKeyboard: () => registry.getKeyboard() }
+    }))
+
+    await expect(port.paste()).rejects.toMatchObject({ code: ErrorCode.TextInsertKeySimulationFailed })
+  })
+
+  it('maps a load failure to TextInsertKeySimulationFailed', async () => {
+    const port = new NutKeyboardPort('win32', async () => {
+      throw new Error('native module missing')
+    })
+
+    await expect(port.paste()).rejects.toMatchObject({ code: ErrorCode.TextInsertKeySimulationFailed })
+  })
+
+  it('configureNutKeyDelay skips the native delay when no keyboard provider is registered', () => {
+    const { nut, keyboard } = makeNut()
+    const setKeyboardDelay = vi.fn()
+    const noProvider: NutKeyboardModule = {
+      ...nut,
+      providerRegistry: {
+        hasKeyboard: () => false,
+        getKeyboard: () => ({ setKeyboardDelay, type: vi.fn(), click: vi.fn() })
+      }
+    }
+
+    configureNutKeyDelay(noProvider, 5)
+
+    expect(keyboard.config.autoDelayMs).toBe(5)
+    expect(setKeyboardDelay).not.toHaveBeenCalled()
+  })
+})
+
+describe('TextInsertService with the nut-js adapter (redteam r2-4)', () => {
+  function memoryClipboard(): ClipboardPort<ClipboardImage> {
+    let text = 'original'
+    const empty: ClipboardImage = { isEmpty: () => true }
+    return {
+      availableFormats: () => (text ? ['text/plain'] : []),
+      readText: () => text,
+      readHTML: () => '',
+      readRTF: () => '',
+      readImage: () => empty,
+      readBuffer: () => Buffer.alloc(0),
+      writeText: (value: string) => {
+        text = value
+      },
+      write: (data) => {
+        text = data.text ?? ''
+      },
+      writeBuffer: () => undefined,
+      clear: () => {
+        text = ''
+      }
+    }
+  }
+
+  it('clipboard insert sends one paste chord and restores the clipboard', async () => {
+    const { nut, registry } = makeNut()
+    const clipboard = memoryClipboard()
+    const service = new TextInsertService({
+      clipboard,
+      keyboard: new NutKeyboardPort('win32', async () => nut),
+      sleep: async () => undefined,
+      platform: 'win32'
+    })
+
+    const result = await service.insertText('dictated text')
+
+    expect(result.method).toBe('clipboard')
+    expect(registry.events).toEqual([{ kind: 'click', keys: [Key.LeftControl, Key.V] }])
+    expect(clipboard.readText()).toBe('original')
+    expect(result.durationMs).toBeLessThan(150)
+  })
+
+  it('keyboard insert finishes promptly instead of 300ms per character', async () => {
+    const { nut, registry } = makeNut()
+    const service = new TextInsertService({
+      clipboard: memoryClipboard(),
+      keyboard: new NutKeyboardPort('win32', async () => nut),
+      sleep: async () => undefined,
+      platform: 'win32'
+    })
+    const text = 'x'.repeat(60)
+
+    const result = await service.insertText(text, 'keyboard')
+
+    expect(result.method).toBe('keyboard')
+    expect(registry.events).toEqual([{ kind: 'type', char: text }])
+    expect(result.durationMs).toBeLessThan(150)
+  })
+})