diff --git a/packages/cli/src/gemini.test.tsx b/packages/cli/src/gemini.test.tsx
index c503bda7ba..5b257ed6f5 100644
--- a/packages/cli/src/gemini.test.tsx
+++ b/packages/cli/src/gemini.test.tsx
@@ -40,6 +40,28 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
   return {
     ...actual,
     recordSlowRender: vi.fn(),
+    writeToStdout: vi.fn((...args) =>
+      process.stdout.write(
+        ...(args as Parameters<typeof process.stdout.write>),
+      ),
+    ),
+    patchStdio: vi.fn(() => () => {}),
+    createInkStdio: vi.fn(() => ({
+      stdout: {
+        write: vi.fn((...args) =>
+          process.stdout.write(
+            ...(args as Parameters<typeof process.stdout.write>),
+          ),
+        ),
+        columns: 80,
+        rows: 24,
+        on: vi.fn(),
+        removeListener: vi.fn(),
+      },
+      stderr: {
+        write: vi.fn(),
+      },
+    })),
   };
 });
 
@@ -149,35 +171,6 @@ vi.mock('./ui/utils/mouse.js', () => ({
   isIncompleteMouseSequence: vi.fn(),
 }));
 
-vi.mock('./utils/stdio.js', async (importOriginal) => {
-  const actual = await importOriginal<typeof import('./utils/stdio.js')>();
-  return {
-    ...actual,
-    writeToStdout: vi.fn((...args) =>
-      process.stdout.write(
-        ...(args as Parameters<typeof process.stdout.write>),
-      ),
-    ),
-    patchStdio: vi.fn(() => () => {}),
-    createInkStdio: vi.fn(() => ({
-      stdout: {
-        write: vi.fn((...args) =>
-          process.stdout.write(
-            ...(args as Parameters<typeof process.stdout.write>),
-          ),
-        ),
-        columns: 80,
-        rows: 24,
-        on: vi.fn(),
-        removeListener: vi.fn(),
-      },
-      stderr: {
-        write: vi.fn(),
-      },
-    })),
-  };
-});
-
 describe('gemini.tsx main function', () => {
   let originalEnvGeminiSandbox: string | undefined;
   let originalEnvSandbox: string | undefined;
diff --git a/packages/cli/src/gemini.tsx b/packages/cli/src/gemini.tsx
index 7d8a4684aa..15617fa9a8 100644
--- a/packages/cli/src/gemini.tsx
+++ b/packages/cli/src/gemini.tsx
@@ -49,6 +49,10 @@ import {
   recordSlowRender,
   coreEvents,
   CoreEvent,
+  createInkStdio,
+  patchStdio,
+  writeToStdout,
+  writeToStderr,
 } from '@google/gemini-cli-core';
 import {
   initializeApp,
@@ -85,12 +89,6 @@ import { disableMouseEvents, enableMouseEvents } from './ui/utils/mouse.js';
 import { ScrollProvider } from './ui/contexts/ScrollProvider.js';
 import ansiEscapes from 'ansi-escapes';
 import { isAlternateBufferEnabled } from './ui/hooks/useAlternateBuffer.js';
-import {
-  createInkStdio,
-  patchStdio,
-  writeToStderr,
-  writeToStdout,
-} from './utils/stdio.js';
 
 import { profiler } from './ui/components/DebugProfiler.js';
 
diff --git a/packages/cli/src/ui/AppContainer.test.tsx b/packages/cli/src/ui/AppContainer.test.tsx
index 8ea2296b3e..43a0de7c92 100644
--- a/packages/cli/src/ui/AppContainer.test.tsx
+++ b/packages/cli/src/ui/AppContainer.test.tsx
@@ -54,6 +54,21 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
     ...actual,
     coreEvents: mockCoreEvents,
     IdeClient: mockIdeClient,
+    writeToStdout: vi.fn((...args) =>
+      process.stdout.write(
+        ...(args as Parameters<typeof process.stdout.write>),
+      ),
+    ),
+    writeToStderr: vi.fn((...args) =>
+      process.stderr.write(
+        ...(args as Parameters<typeof process.stderr.write>),
+      ),
+    ),
+    patchStdio: vi.fn(() => () => {}),
+    createInkStdio: vi.fn(() => ({
+      stdout: process.stdout,
+      stderr: process.stderr,
+    })),
   };
 });
 import type { LoadedSettings } from '../config/settings.js';
@@ -126,19 +141,6 @@ vi.mock('./utils/mouse.js', () => ({
   enableMouseEvents: vi.fn(),
   disableMouseEvents: vi.fn(),
 }));
-vi.mock('../utils/stdio.js', () => ({
-  writeToStdout: vi.fn((...args) =>
-    process.stdout.write(...(args as Parameters<typeof process.stdout.write>)),
-  ),
-  writeToStderr: vi.fn((...args) =>
-    process.stderr.write(...(args as Parameters<typeof process.stderr.write>)),
-  ),
-  patchStdio: vi.fn(() => () => {}),
-  createInkStdio: vi.fn(() => ({
-    stdout: process.stdout,
-    stderr: process.stderr,
-  })),
-}));
 
 import { useHistory } from './hooks/useHistoryManager.js';
 import { useThemeCommand } from './hooks/useThemeCommand.js';
@@ -163,10 +165,9 @@ import { useLoadingIndicator } from './hooks/useLoadingIndicator.js';
 import { useKeypress, type Key } from './hooks/useKeypress.js';
 import { measureElement } from 'ink';
 import { useTerminalSize } from './hooks/useTerminalSize.js';
-import { ShellExecutionService } from '@google/gemini-cli-core';
+import { ShellExecutionService, writeToStdout } from '@google/gemini-cli-core';
 import { type ExtensionManager } from '../config/extension-manager.js';
 import { enableMouseEvents, disableMouseEvents } from './utils/mouse.js';
-import { writeToStdout } from '../utils/stdio.js';
 
 describe('AppContainer State Management', () => {
   let mockConfig: Config;
diff --git a/packages/cli/src/ui/AppContainer.tsx b/packages/cli/src/ui/AppContainer.tsx
index 4b2bac8868..1ae809a96e 100644
--- a/packages/cli/src/ui/AppContainer.tsx
+++ b/packages/cli/src/ui/AppContainer.tsx
@@ -110,7 +110,7 @@ import { disableMouseEvents, enableMouseEvents } from './utils/mouse.js';
 import { useAlternateBuffer } from './hooks/useAlternateBuffer.js';
 import { useSettings } from './contexts/SettingsContext.js';
 import { enableSupportedProtocol } from './utils/kittyProtocolDetector.js';
-import { writeToStdout } from '../utils/stdio.js';
+import { writeToStdout } from '@google/gemini-cli-core';
 
 const WARNING_PROMPT_DURATION_MS = 1000;
 const QUEUE_ERROR_DISPLAY_DURATION_MS = 3000;
diff --git a/packages/cli/src/ui/hooks/useBracketedPaste.ts b/packages/cli/src/ui/hooks/useBracketedPaste.ts
index 3a9382c110..b8a763af42 100644
--- a/packages/cli/src/ui/hooks/useBracketedPaste.ts
+++ b/packages/cli/src/ui/hooks/useBracketedPaste.ts
@@ -5,7 +5,7 @@
  */
 
 import { useEffect } from 'react';
-import { writeToStdout } from '../../utils/stdio.js';
+import { writeToStdout } from '@google/gemini-cli-core';
 
 const ENABLE_BRACKETED_PASTE = '\x1b[?2004h';
 const DISABLE_BRACKETED_PASTE = '\x1b[?2004l';
diff --git a/packages/cli/src/ui/utils/mouse.ts b/packages/cli/src/ui/utils/mouse.ts
index e12aa5927c..e5f2cd8241 100644
--- a/packages/cli/src/ui/utils/mouse.ts
+++ b/packages/cli/src/ui/utils/mouse.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { writeToStdout } from '../../utils/stdio.js';
+import { writeToStdout } from '@google/gemini-cli-core';
 import {
   SGR_MOUSE_REGEX,
   X11_MOUSE_REGEX,
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index fe34a98cac..ad227b8db7 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -144,3 +144,6 @@ export * from './test-utils/index.js';
 
 // Export hook types
 export * from './hooks/types.js';
+
+// Export stdio utils
+export * from './utils/stdio.js';
diff --git a/packages/cli/src/utils/stdio.test.ts b/packages/core/src/utils/stdio.test.ts
similarity index 94%
rename from packages/cli/src/utils/stdio.test.ts
rename to packages/core/src/utils/stdio.test.ts
index f6fb0d5535..2c1a74fecc 100644
--- a/packages/cli/src/utils/stdio.test.ts
+++ b/packages/core/src/utils/stdio.test.ts
@@ -6,9 +6,9 @@
 
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import { patchStdio, createInkStdio } from './stdio.js';
-import { coreEvents } from '@google/gemini-cli-core';
+import { coreEvents } from './events.js';
 
-vi.mock('@google/gemini-cli-core', () => ({
+vi.mock('./events.js', () => ({
   coreEvents: {
     emitOutput: vi.fn(),
   },
diff --git a/packages/cli/src/utils/stdio.ts b/packages/core/src/utils/stdio.ts
similarity index 98%
rename from packages/cli/src/utils/stdio.ts
rename to packages/core/src/utils/stdio.ts
index fec66deb6c..74b5361160 100644
--- a/packages/cli/src/utils/stdio.ts
+++ b/packages/core/src/utils/stdio.ts
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { coreEvents } from '@google/gemini-cli-core';
+import { coreEvents } from './events.js';
 
 // Capture the original stdout and stderr write methods before any monkey patching occurs.
 const originalStdoutWrite = process.stdout.write.bind(process.stdout);