Migrate console to coreEvents.emitFeedback or debugLogger (#15219)

GEMINI.md

@@ -391,6 +391,15 @@ When working in the `/docs` directory, follow the guidelines in this section:
 Only write high-value comments if at all. Avoid talking to the user through
 comments.
 
+## Logging and Error Handling
+
+- **Avoid Console Statements:** Do not use `console.log`, `console.error`, or
+  similar methods directly.
+- **Non-User-Facing Logs:** For developer-facing debug messages, use
+  `debugLogger` (from `@google/gemini-cli-core`).
+- **User-Facing Feedback:** To surface errors or warnings to the user, use
+  `coreEvents.emitFeedback` (from `@google/gemini-cli-core`).
+
 ## General requirements
 
 - If there is something you do not understand or is ambiguous, seek confirmation

eslint.config.js

@@ -164,6 +164,7 @@ export default tseslint.config(
       'prefer-arrow-callback': 'error',
       'prefer-const': ['error', { destructuring: 'all' }],
       radix: 'error',
+      'no-console': 'error',
       'default-case': 'error',
       '@typescript-eslint/await-thenable': ['error'],
       '@typescript-eslint/no-floating-promises': ['error'],

packages/a2a-server/src/commands/command-registry.ts

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import { debugLogger } from '@google/gemini-cli-core';
 import { ExtensionsCommand } from './extensions.js';
 import { InitCommand } from './init.js';
 import { RestoreCommand } from './restore.js';
@@ -20,7 +21,7 @@ class CommandRegistry {
 
   register(command: Command) {
     if (this.commands.has(command.name)) {
-      console.warn(`Command ${command.name} already registered. Skipping.`);
+      debugLogger.warn(`Command ${command.name} already registered. Skipping.`);
       return;
     }
 

packages/a2a-server/src/config/settings.test.ts

@@ -9,6 +9,7 @@ import * as fs from 'node:fs';
 import * as path from 'node:path';
 import * as os from 'node:os';
 import { loadSettings, USER_SETTINGS_PATH } from './settings.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 const mocks = vi.hoisted(() => {
   const suffix = Math.random().toString(36).slice(2);
@@ -75,7 +76,7 @@ describe('loadSettings', () => {
         fs.rmSync(mockWorkspaceDir, { recursive: true, force: true });
       }
     } catch (e) {
-      console.error('Failed to cleanup temp dirs', e);
+      debugLogger.error('Failed to cleanup temp dirs', e);
     }
     vi.restoreAllMocks();
   });

packages/a2a-server/src/http/app.ts

@@ -25,7 +25,7 @@ import { loadConfig, loadEnvironment, setTargetDir } from '../config/config.js';
 import { loadSettings } from '../config/settings.js';
 import { loadExtensions } from '../config/extension.js';
 import { commandRegistry } from '../commands/command-registry.js';
-import { SimpleExtensionLoader } from '@google/gemini-cli-core';
+import { debugLogger, SimpleExtensionLoader } from '@google/gemini-cli-core';
 import type { Command, CommandArgument } from '../commands/types.js';
 import { GitService } from '@google/gemini-cli-core';
 
@@ -239,7 +239,7 @@ export async function createApp() {
         ): CommandResponse | undefined => {
           const commandName = command.name;
           if (visited.includes(commandName)) {
-            console.warn(
+            debugLogger.warn(
               `Command ${commandName} already inserted in the response, skipping`,
             );
             return undefined;

packages/cli/src/gemini.test.tsx

@@ -29,6 +29,7 @@ import {
   type Config,
   type ResumedSessionData,
   debugLogger,
+  coreEvents,
 } from '@google/gemini-cli-core';
 import { act } from 'react';
 import { type InitializationResult } from './core/initializer.js';
@@ -819,9 +820,7 @@ describe('gemini.tsx main function kitty protocol', () => {
       .mockImplementation((code) => {
         throw new MockProcessExitError(code);
       });
-    const consoleErrorSpy = vi
+    const emitFeedbackSpy = vi.spyOn(coreEvents, 'emitFeedback');
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
 
     vi.mocked(loadSettings).mockReturnValue({
       merged: { advanced: {}, security: { auth: {} }, ui: { theme: 'test' } },
@@ -875,12 +874,13 @@ describe('gemini.tsx main function kitty protocol', () => {
       if (!(e instanceof MockProcessExitError)) throw e;
     }
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(emitFeedbackSpy).toHaveBeenCalledWith(
+      'error',
       expect.stringContaining('Error resuming session: Session not found'),
     );
     expect(processExitSpy).toHaveBeenCalledWith(42);
     processExitSpy.mockRestore();
-    consoleErrorSpy.mockRestore();
+    emitFeedbackSpy.mockRestore();
   });
 
   it.skip('should log error when cleanupExpiredSessions fails', async () => {

packages/cli/src/gemini.tsx

@@ -41,6 +41,7 @@ import {
   type ResumedSessionData,
   type OutputPayload,
   type ConsoleLogPayload,
+  type UserFeedbackPayload,
   sessionId,
   logUserPrompt,
   AuthType,
@@ -597,7 +598,8 @@ export async function main() {
         // Use the existing session ID to continue recording to the same session
         config.setSessionId(resumedSessionData.conversation.sessionId);
       } catch (error) {
-        console.error(
+        coreEvents.emitFeedback(
+          'error',
           `Error resuming session: ${error instanceof Error ? error.message : 'Unknown error'}`,
         );
         await runExitCleanup();
@@ -719,13 +721,25 @@ export function initializeOutputListenersAndFlush() {
       }
     });
 
-    coreEvents.on(CoreEvent.ConsoleLog, (payload: ConsoleLogPayload) => {
+    if (coreEvents.listenerCount(CoreEvent.ConsoleLog) === 0) {
-      if (payload.type === 'error' || payload.type === 'warn') {
+      coreEvents.on(CoreEvent.ConsoleLog, (payload: ConsoleLogPayload) => {
-        writeToStderr(payload.content);
+        if (payload.type === 'error' || payload.type === 'warn') {
-      } else {
+          writeToStderr(payload.content);
-        writeToStdout(payload.content);
+        } else {
-      }
+          writeToStdout(payload.content);
-    });
+        }
+      });
+    }
+
+    if (coreEvents.listenerCount(CoreEvent.UserFeedback) === 0) {
+      coreEvents.on(CoreEvent.UserFeedback, (payload: UserFeedbackPayload) => {
+        if (payload.severity === 'error' || payload.severity === 'warning') {
+          writeToStderr(payload.message);
+        } else {
+          writeToStdout(payload.message);
+        }
+      });
+    }
   }
   coreEvents.drainBacklogs();
 }

packages/cli/src/nonInteractiveCli.test.ts

@@ -44,6 +44,7 @@ const mockCoreEvents = vi.hoisted(() => ({
   off: vi.fn(),
   drainBacklogs: vi.fn(),
   emit: vi.fn(),
+  emitFeedback: vi.fn(),
 }));
 
 vi.mock('@google/gemini-cli-core', async (importOriginal) => {
@@ -785,11 +786,6 @@ describe('runNonInteractive', () => {
       throw testError;
     });
 
-    // Mock console.error to capture JSON error output
-    const consoleErrorJsonSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
-
     let thrownError: Error | null = null;
     try {
       await runNonInteractive({
@@ -807,7 +803,8 @@ describe('runNonInteractive', () => {
     // Should throw because of mocked process.exit
     expect(thrownError?.message).toBe('process.exit(1) called');
 
-    expect(consoleErrorJsonSpy).toHaveBeenCalledWith(
+    expect(mockCoreEvents.emitFeedback).toHaveBeenCalledWith(
+      'error',
       JSON.stringify(
         {
           session_id: 'test-session-id',
@@ -831,11 +828,6 @@ describe('runNonInteractive', () => {
       throw fatalError;
     });
 
-    // Mock console.error to capture JSON error output
-    const consoleErrorJsonSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
-
     let thrownError: Error | null = null;
     try {
       await runNonInteractive({
@@ -853,7 +845,8 @@ describe('runNonInteractive', () => {
     // Should throw because of mocked process.exit with custom exit code
     expect(thrownError?.message).toBe('process.exit(42) called');
 
-    expect(consoleErrorJsonSpy).toHaveBeenCalledWith(
+    expect(mockCoreEvents.emitFeedback).toHaveBeenCalledWith(
+      'error',
       JSON.stringify(
         {
           session_id: 'test-session-id',

packages/cli/src/services/FileCommandLoader.ts

@@ -10,7 +10,7 @@ import toml from '@iarna/toml';
 import { glob } from 'glob';
 import { z } from 'zod';
 import type { Config } from '@google/gemini-cli-core';
-import { Storage } from '@google/gemini-cli-core';
+import { Storage, coreEvents } from '@google/gemini-cli-core';
 import type { ICommandLoader } from './types.js';
 import type {
   CommandContext,
@@ -126,7 +126,8 @@ export class FileCommandLoader implements ICommandLoader {
           !signal.aborted &&
           (error as { code?: string })?.code !== 'ENOENT'
         ) {
-          console.error(
+          coreEvents.emitFeedback(
+            'error',
             `[FileCommandLoader] Error loading commands from ${dirInfo.path}:`,
             error,
           );
@@ -189,7 +190,8 @@ export class FileCommandLoader implements ICommandLoader {
     try {
       fileContent = await fs.readFile(filePath, 'utf-8');
     } catch (error: unknown) {
-      console.error(
+      coreEvents.emitFeedback(
+        'error',
         `[FileCommandLoader] Failed to read file ${filePath}:`,
         error instanceof Error ? error.message : String(error),
       );
@@ -200,7 +202,8 @@ export class FileCommandLoader implements ICommandLoader {
     try {
       parsed = toml.parse(fileContent);
     } catch (error: unknown) {
-      console.error(
+      coreEvents.emitFeedback(
+        'error',
         `[FileCommandLoader] Failed to parse TOML file ${filePath}:`,
         error instanceof Error ? error.message : String(error),
       );
@@ -210,7 +213,8 @@ export class FileCommandLoader implements ICommandLoader {
     const validationResult = TomlCommandDefSchema.safeParse(parsed);
 
     if (!validationResult.success) {
-      console.error(
+      coreEvents.emitFeedback(
+        'error',
         `[FileCommandLoader] Skipping invalid command file: ${filePath}. Validation errors:`,
         validationResult.error.flatten(),
       );
@@ -278,7 +282,8 @@ export class FileCommandLoader implements ICommandLoader {
         _args: string,
       ): Promise<SlashCommandActionReturn> => {
         if (!context.invocation) {
-          console.error(
+          coreEvents.emitFeedback(
+            'error',
             `[FileCommandLoader] Critical error: Command '${baseCommandName}' was executed without invocation context.`,
           );
           return {

packages/cli/src/ui/AppContainer.tsx

@@ -842,16 +842,8 @@ Logging in with Google... Restarting Gemini CLI to continue.
   const handleClearScreen = useCallback(() => {
     historyManager.clearItems();
     clearConsoleMessagesState();
-    if (!isAlternateBuffer) {
-      console.clear();
-    }
     refreshStatic();
-  }, [
+  }, [historyManager, clearConsoleMessagesState, refreshStatic]);
-    historyManager,
-    clearConsoleMessagesState,
-    refreshStatic,
-    isAlternateBuffer,
-  ]);
 
   const { handleInput: vimHandleInput } = useVim(buffer, handleFinalSubmit);
 

packages/cli/src/ui/IdeIntegrationNudge.test.tsx

@@ -4,14 +4,30 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect, vi, afterEach } from 'vitest';
+import { describe, it, expect, vi, afterEach, beforeEach } from 'vitest';
-import { render } from 'ink-testing-library';
+import { render } from '../test-utils/render.js';
 import { act } from 'react';
 import { IdeIntegrationNudge } from './IdeIntegrationNudge.js';
 import { KeypressProvider } from './contexts/KeypressContext.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 const delay = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));
 
+// Mock debugLogger
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    debugLogger: {
+      log: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+      debug: vi.fn(),
+    },
+  };
+});
+
 describe('IdeIntegrationNudge', () => {
   const defaultProps = {
     ide: {
@@ -21,24 +37,20 @@ describe('IdeIntegrationNudge', () => {
     onComplete: vi.fn(),
   };
 
-  const originalError = console.error;
-
   afterEach(() => {
-    console.error = originalError;
     vi.restoreAllMocks();
     vi.unstubAllEnvs();
   });
 
   beforeEach(() => {
-    console.error = (...args) => {
+    vi.mocked(debugLogger.warn).mockImplementation((...args) => {
       if (
         typeof args[0] === 'string' &&
         /was not wrapped in act/.test(args[0])
       ) {
         return;
       }
-      originalError.call(console, ...args);
+    });
-    };
     vi.stubEnv('GEMINI_CLI_IDE_SERVER_PORT', '');
     vi.stubEnv('GEMINI_CLI_IDE_WORKSPACE_PATH', '');
   });

packages/cli/src/ui/auth/AuthInProgress.test.tsx

@@ -5,12 +5,27 @@
  */
 
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
-import { render } from 'ink-testing-library';
+import { render } from '../../test-utils/render.js';
 import { act } from 'react';
 import { AuthInProgress } from './AuthInProgress.js';
 import { useKeypress, type Key } from '../hooks/useKeypress.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 // Mock dependencies
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    debugLogger: {
+      log: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+      debug: vi.fn(),
+    },
+  };
+});
+
 vi.mock('../hooks/useKeypress.js', () => ({
   useKeypress: vi.fn(),
 }));
@@ -22,24 +37,20 @@ vi.mock('../components/CliSpinner.js', () => ({
 describe('AuthInProgress', () => {
   const onTimeout = vi.fn();
 
-  const originalError = console.error;
-
   beforeEach(() => {
     vi.clearAllMocks();
     vi.useFakeTimers();
-    console.error = (...args) => {
+    vi.mocked(debugLogger.error).mockImplementation((...args) => {
       if (
         typeof args[0] === 'string' &&
         args[0].includes('was not wrapped in act')
       ) {
         return;
       }
-      originalError.call(console, ...args);
+    });
-    };
   });
 
   afterEach(() => {
-    console.error = originalError;
     vi.useRealTimers();
   });
 

packages/cli/src/ui/components/EditorSettingsDialog.test.tsx

@@ -12,6 +12,7 @@ import type { LoadedSettings } from '../../config/settings.js';
 import { KeypressProvider } from '../contexts/KeypressContext.js';
 import { act } from 'react';
 import { waitFor } from '../../test-utils/async.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 vi.mock('@google/gemini-cli-core', async (importOriginal) => {
   const actual =
@@ -101,7 +102,7 @@ describe('EditorSettingsDialog', () => {
     await waitFor(() => {
       const frame = lastFrame() || '';
       if (!frame.includes('> Apply To')) {
-        console.log(
+        debugLogger.debug(
           'Waiting for scope focus. Current frame:',
           JSON.stringify(frame),
         );
@@ -166,7 +167,7 @@ describe('EditorSettingsDialog', () => {
 
     const frame = lastFrame() || '';
     if (!frame.includes('(Also modified')) {
-      console.log(
+      debugLogger.debug(
         'Modified message test failure. Frame:',
         JSON.stringify(frame),
       );

packages/cli/src/ui/components/EditorSettingsDialog.tsx

@@ -24,6 +24,7 @@ import {
   EDITOR_DISPLAY_NAMES,
 } from '@google/gemini-cli-core';
 import { useKeypress } from '../hooks/useKeypress.js';
+import { coreEvents } from '@google/gemini-cli-core';
 
 interface EditorDialogProps {
   onSelect: (
@@ -68,7 +69,10 @@ export function EditorSettingsDialog({
       )
     : 0;
   if (editorIndex === -1) {
-    console.error(`Editor is not supported: ${currentPreference}`);
+    coreEvents.emitFeedback(
+      'error',
+      `Editor is not supported: ${currentPreference}`,
+    );
     editorIndex = 0;
   }
 

packages/cli/src/ui/components/IdeTrustChangeDialog.test.tsx

@@ -8,6 +8,7 @@ import { vi, describe, it, expect, beforeEach } from 'vitest';
 import * as processUtils from '../../utils/processUtils.js';
 import { renderWithProviders } from '../../test-utils/render.js';
 import { IdeTrustChangeDialog } from './IdeTrustChangeDialog.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 describe('IdeTrustChangeDialog', () => {
   beforeEach(() => {
@@ -39,8 +40,8 @@ describe('IdeTrustChangeDialog', () => {
   });
 
   it('renders a generic message and logs an error for NONE reason', () => {
-    const consoleErrorSpy = vi
+    const debugLoggerWarnSpy = vi
-      .spyOn(console, 'error')
+      .spyOn(debugLogger, 'warn')
       .mockImplementation(() => {});
     const { lastFrame } = renderWithProviders(
       <IdeTrustChangeDialog reason="NONE" />,
@@ -48,7 +49,7 @@ describe('IdeTrustChangeDialog', () => {
 
     const frameText = lastFrame();
     expect(frameText).toContain('Workspace trust has changed.');
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
       'IdeTrustChangeDialog rendered with unexpected reason "NONE"',
     );
   });

packages/cli/src/ui/components/IdeTrustChangeDialog.tsx

@@ -9,6 +9,7 @@ import { theme } from '../semantic-colors.js';
 import { useKeypress } from '../hooks/useKeypress.js';
 import { relaunchApp } from '../../utils/processUtils.js';
 import { type RestartReason } from '../hooks/useIdeTrustListener.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 interface IdeTrustChangeDialogProps {
   reason: RestartReason;
@@ -28,7 +29,7 @@ export const IdeTrustChangeDialog = ({ reason }: IdeTrustChangeDialogProps) => {
   let message = 'Workspace trust has changed.';
   if (reason === 'NONE') {
     // This should not happen, but provides a fallback and a debug log.
-    console.error(
+    debugLogger.warn(
       'IdeTrustChangeDialog rendered with unexpected reason "NONE"',
     );
   } else if (reason === 'CONNECTION_CHANGE') {

packages/cli/src/ui/components/InputPrompt.test.tsx

@@ -15,7 +15,7 @@ import {
   calculateTransformedLine,
 } from './shared/text-buffer.js';
 import type { Config } from '@google/gemini-cli-core';
-import { ApprovalMode } from '@google/gemini-cli-core';
+import { ApprovalMode, debugLogger } from '@google/gemini-cli-core';
 import * as path from 'node:path';
 import type { CommandContext, SlashCommand } from '../commands/types.js';
 import { CommandKind } from '../commands/types.js';
@@ -577,8 +577,8 @@ describe('InputPrompt', () => {
     });
 
     it('should handle errors during clipboard operations', async () => {
-      const consoleErrorSpy = vi
+      const debugLoggerErrorSpy = vi
-        .spyOn(console, 'error')
+        .spyOn(debugLogger, 'error')
         .mockImplementation(() => {});
       vi.mocked(clipboardUtils.clipboardHasImage).mockRejectedValue(
         new Error('Clipboard error'),
@@ -592,14 +592,14 @@ describe('InputPrompt', () => {
         stdin.write('\x16'); // Ctrl+V
       });
       await waitFor(() => {
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
           'Error handling clipboard image:',
           expect.any(Error),
         );
       });
       expect(mockBuffer.setText).not.toHaveBeenCalled();
 
-      consoleErrorSpy.mockRestore();
+      debugLoggerErrorSpy.mockRestore();
       unmount();
     });
   });

packages/cli/src/ui/components/InputPrompt.tsx

@@ -24,7 +24,7 @@ import { useKeypress } from '../hooks/useKeypress.js';
 import { keyMatchers, Command } from '../keyMatchers.js';
 import type { CommandContext, SlashCommand } from '../commands/types.js';
 import type { Config } from '@google/gemini-cli-core';
-import { ApprovalMode } from '@google/gemini-cli-core';
+import { ApprovalMode, debugLogger } from '@google/gemini-cli-core';
 import {
   parseInputForHighlighting,
   parseSegmentsFromTokens,
@@ -354,7 +354,7 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
       const offset = buffer.getOffset();
       buffer.replaceRangeByOffset(offset, offset, textToInsert);
     } catch (error) {
-      console.error('Error handling clipboard image:', error);
+      debugLogger.error('Error handling clipboard image:', error);
     }
   }, [buffer, config]);
 

packages/cli/src/ui/components/Notifications.tsx

@@ -12,7 +12,7 @@ import { theme } from '../semantic-colors.js';
 import { StreamingState } from '../types.js';
 import { UpdateNotification } from './UpdateNotification.js';
 
-import { GEMINI_DIR, Storage } from '@google/gemini-cli-core';
+import { GEMINI_DIR, Storage, debugLogger } from '@google/gemini-cli-core';
 
 import * as fs from 'node:fs/promises';
 import os from 'node:os';
@@ -66,7 +66,7 @@ export const Notifications = () => {
           });
           await fs.writeFile(screenReaderNudgeFilePath, 'true');
         } catch (error) {
-          console.error('Error storing screen reader nudge', error);
+          debugLogger.error('Error storing screen reader nudge', error);
         }
       }
     };

packages/cli/src/ui/components/SettingsDialog.tsx

@@ -42,7 +42,7 @@ import {
   type SettingsValue,
   TOGGLE_TYPES,
 } from '../../config/settingsSchema.js';
-import { debugLogger } from '@google/gemini-cli-core';
+import { coreEvents, debugLogger } from '@google/gemini-cli-core';
 import { keyMatchers, Command } from '../keyMatchers.js';
 import type { Config } from '@google/gemini-cli-core';
 import { useUIState } from '../contexts/UIStateContext.js';
@@ -254,7 +254,11 @@ export function SettingsDialog({
             if (key === 'general.vimMode' && newValue !== vimEnabled) {
               // Call toggleVimEnabled to sync the VimModeContext local state
               toggleVimEnabled().catch((error) => {
-                console.error('Failed to toggle vim mode:', error);
+                coreEvents.emitFeedback(
+                  'error',
+                  'Failed to toggle vim mode:',
+                  error,
+                );
               });
             }
 

packages/cli/src/ui/components/shared/MaxSizedBox.tsx

@@ -10,6 +10,7 @@ import stringWidth from 'string-width';
 import { theme } from '../../semantic-colors.js';
 import { toCodePoints } from '../../utils/textUtils.js';
 import { useOverflowActions } from '../../contexts/OverflowContext.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 let enableDebugLog = false;
 
@@ -28,7 +29,7 @@ function debugReportError(message: string, element: React.ReactNode) {
   if (!enableDebugLog) return;
 
   if (!React.isValidElement(element)) {
-    console.error(
+    debugLogger.warn(
       message,
       `Invalid element: '${String(element)}' typeof=${typeof element}`,
     );
@@ -44,10 +45,13 @@ function debugReportError(message: string, element: React.ReactNode) {
     const lineNumber = elementWithSource._source?.lineNumber;
     sourceMessage = fileName ? `${fileName}:${lineNumber}` : '<Unknown file>';
   } catch (error) {
-    console.error('Error while trying to get file name:', error);
+    debugLogger.warn('Error while trying to get file name:', error);
   }
 
-  console.error(message, `${String(element.type)}. Source: ${sourceMessage}`);
+  debugLogger.warn(
+    message,
+    `${String(element.type)}. Source: ${sourceMessage}`,
+  );
 }
 interface MaxSizedBoxProps {
   children?: React.ReactNode;

packages/cli/src/ui/components/shared/text-buffer.ts

@@ -10,7 +10,12 @@ import os from 'node:os';
 import pathMod from 'node:path';
 import * as path from 'node:path';
 import { useState, useCallback, useEffect, useMemo, useReducer } from 'react';
-import { coreEvents, CoreEvent, unescapePath } from '@google/gemini-cli-core';
+import {
+  coreEvents,
+  CoreEvent,
+  debugLogger,
+  unescapePath,
+} from '@google/gemini-cli-core';
 import {
   toCodePoints,
   cpLen,
@@ -1411,7 +1416,7 @@ function textBufferReducerLogic(
             break;
           default: {
             const exhaustiveCheck: never = dir;
-            console.error(
+            debugLogger.error(
               `Unknown visual movement direction: ${exhaustiveCheck}`,
             );
             return state;
@@ -1751,7 +1756,7 @@ function textBufferReducerLogic(
 
     default: {
       const exhaustiveCheck: never = action;
-      console.error(`Unknown action encountered: ${exhaustiveCheck}`);
+      debugLogger.error(`Unknown action encountered: ${exhaustiveCheck}`);
       return state;
     }
   }
@@ -2173,7 +2178,11 @@ export function useTextBuffer({
         newText = newText.replace(/\r\n?/g, '\n');
         dispatch({ type: 'set_text', payload: newText, pushToUndo: false });
       } catch (err) {
-        console.error('[useTextBuffer] external editor error', err);
+        coreEvents.emitFeedback(
+          'error',
+          '[useTextBuffer] external editor error',
+          err,
+        );
       } finally {
         coreEvents.emit(CoreEvent.ExternalEditorClosed);
         if (wasRaw) setRawMode?.(true);

packages/cli/src/ui/hooks/atCommandProcessor.ts

@@ -502,7 +502,7 @@ export async function handleAtCommand({
     const errorMessages = resourceReadDisplays
       .filter((d) => d.status === ToolCallStatus.Error)
       .map((d) => d.resultDisplay);
-    console.error(errorMessages);
+    debugLogger.error(errorMessages);
     const errorMsg = `Exiting due to an error processing the @ command: ${firstError.resultDisplay}`;
     return { processedQuery: null, error: errorMsg };
   }

packages/cli/src/ui/hooks/slashCommandProcessor.test.tsx

@@ -244,7 +244,6 @@ describe('useSlashCommandProcessor', () => {
       });
 
       expect(mockClearItems).toHaveBeenCalled();
-      expect(console.clear).not.toHaveBeenCalled();
     });
 
     it('should call console.clear if alternate buffer is not active', async () => {
@@ -262,7 +261,6 @@ describe('useSlashCommandProcessor', () => {
       });
 
       expect(mockClearItems).toHaveBeenCalled();
-      expect(console.clear).toHaveBeenCalled();
     });
   });
 

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -50,7 +50,6 @@ import {
   type ExtensionUpdateStatus,
 } from '../state/extensions.js';
 import { appEvents } from '../../utils/events.js';
-import { useAlternateBuffer } from './useAlternateBuffer.js';
 import {
   LogoutConfirmationDialog,
   LogoutChoice,
@@ -96,7 +95,6 @@ export const useSlashCommandProcessor = (
   const [commands, setCommands] = useState<readonly SlashCommand[] | undefined>(
     undefined,
   );
-  const alternateBuffer = useAlternateBuffer();
   const [reloadTrigger, setReloadTrigger] = useState(0);
 
   const reloadCommands = useCallback(() => {
@@ -212,9 +210,6 @@ export const useSlashCommandProcessor = (
         addItem,
         clear: () => {
           clearItems();
-          if (!alternateBuffer) {
-            console.clear();
-          }
           refreshStatic();
           setBannerVisible(false);
         },
@@ -238,7 +233,6 @@ export const useSlashCommandProcessor = (
       },
     }),
     [
-      alternateBuffer,
       config,
       settings,
       gitService,

packages/cli/src/ui/hooks/useIncludeDirsTrust.tsx

@@ -8,7 +8,10 @@ import { useEffect } from 'react';
 import type { Config } from '@google/gemini-cli-core';
 import { loadTrustedFolders } from '../../config/trustedFolders.js';
 import { expandHomeDir } from '../utils/directoryUtils.js';
-import { refreshServerHierarchicalMemory } from '@google/gemini-cli-core';
+import {
+  debugLogger,
+  refreshServerHierarchicalMemory,
+} from '@google/gemini-cli-core';
 import { MultiFolderTrustDialog } from '../components/MultiFolderTrustDialog.js';
 import type { UseHistoryManagerReturn } from './useHistoryManager.js';
 import { MessageType, type HistoryItem } from '../types.js';
@@ -133,7 +136,7 @@ export function useIncludeDirsTrust(
     }
 
     if (undefinedTrustDirs.length > 0) {
-      console.log(
+      debugLogger.log(
         'Creating custom dialog with undecidedDirs:',
         undefinedTrustDirs,
       );

packages/cli/src/ui/hooks/useSelectionList.ts

@@ -7,6 +7,7 @@
 import { useReducer, useRef, useEffect, useCallback } from 'react';
 import { useKeypress, type Key } from './useKeypress.js';
 import { keyMatchers, Command } from '../keyMatchers.js';
+import { debugLogger } from '@google/gemini-cli-core';
 
 export interface SelectionListItem<T> {
   key: string;
@@ -198,7 +199,7 @@ function selectionListReducer(
 
     default: {
       const exhaustiveCheck: never = action;
-      console.error(`Unknown selection list action: ${exhaustiveCheck}`);
+      debugLogger.warn(`Unknown selection list action: ${exhaustiveCheck}`);
       return state;
     }
   }

packages/cli/src/ui/hooks/useSessionBrowser.test.ts

@@ -19,6 +19,7 @@ import type {
   ConversationRecord,
   MessageRecord,
 } from '@google/gemini-cli-core';
+import { coreEvents } from '@google/gemini-cli-core';
 
 // Mock modules
 vi.mock('fs/promises');
@@ -52,6 +53,7 @@ describe('useSessionBrowser', () => {
 
   beforeEach(() => {
     vi.resetAllMocks();
+    vi.spyOn(coreEvents, 'emitFeedback').mockImplementation(() => {});
     mockedPath.join.mockImplementation((...args) => args.join('/'));
     vi.mocked(mockConfig.storage.getProjectTempDir).mockReturnValue(
       MOCKED_PROJECT_TEMP_DIR,
@@ -100,9 +102,6 @@ describe('useSessionBrowser', () => {
       fileName: MOCKED_FILENAME,
     } as SessionInfo;
     mockedFs.readFile.mockRejectedValue(new Error('File not found'));
-    const consoleErrorSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
 
     const { result } = renderHook(() =>
       useSessionBrowser(mockConfig, mockOnLoadHistory),
@@ -112,9 +111,12 @@ describe('useSessionBrowser', () => {
       await result.current.handleResumeSession(mockSession);
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalled();
+    expect(coreEvents.emitFeedback).toHaveBeenCalledWith(
+      'error',
+      'Error resuming session:',
+      expect.any(Error),
+    );
     expect(result.current.isSessionBrowserOpen).toBe(false);
-    consoleErrorSpy.mockRestore();
   });
 
   it('should handle JSON parse error', async () => {
@@ -124,9 +126,6 @@ describe('useSessionBrowser', () => {
       fileName: MOCKED_FILENAME,
     } as SessionInfo;
     mockedFs.readFile.mockResolvedValue('invalid json');
-    const consoleErrorSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
 
     const { result } = renderHook(() =>
       useSessionBrowser(mockConfig, mockOnLoadHistory),
@@ -136,9 +135,12 @@ describe('useSessionBrowser', () => {
       await result.current.handleResumeSession(mockSession);
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalled();
+    expect(coreEvents.emitFeedback).toHaveBeenCalledWith(
+      'error',
+      'Error resuming session:',
+      expect.any(Error),
+    );
     expect(result.current.isSessionBrowserOpen).toBe(false);
-    consoleErrorSpy.mockRestore();
   });
 });
 

packages/cli/src/ui/hooks/useSessionBrowser.ts

@@ -14,7 +14,7 @@ import type {
   ResumedSessionData,
 } from '@google/gemini-cli-core';
 import type { Part } from '@google/genai';
-import { partListUnionToString } from '@google/gemini-cli-core';
+import { partListUnionToString, coreEvents } from '@google/gemini-cli-core';
 import type { SessionInfo } from '../../utils/sessionUtils.js';
 import { MessageType, ToolCallStatus } from '../types.js';
 
@@ -79,7 +79,7 @@ export const useSessionBrowser = (
             resumedSessionData,
           );
         } catch (error) {
-          console.error('Error resuming session:', error);
+          coreEvents.emitFeedback('error', 'Error resuming session:', error);
           setIsSessionBrowserOpen(false);
         }
       },
@@ -103,7 +103,7 @@ export const useSessionBrowser = (
             chatRecordingService.deleteSession(session.file);
           }
         } catch (error) {
-          console.error('Error deleting session:', error);
+          coreEvents.emitFeedback('error', 'Error deleting session:', error);
           throw error;
         }
       },

packages/cli/src/ui/hooks/useShellHistory.ts

@@ -7,7 +7,7 @@
 import { useState, useEffect, useCallback } from 'react';
 import * as fs from 'node:fs/promises';
 import * as path from 'node:path';
-import { isNodeError, Storage } from '@google/gemini-cli-core';
+import { debugLogger, isNodeError, Storage } from '@google/gemini-cli-core';
 
 const MAX_HISTORY_LENGTH = 100;
 
@@ -52,7 +52,7 @@ async function readHistoryFile(filePath: string): Promise<string[]> {
     return result;
   } catch (err) {
     if (isNodeError(err) && err.code === 'ENOENT') return [];
-    console.error('Error reading history:', err);
+    debugLogger.error('Error reading history:', err);
     return [];
   }
 }
@@ -65,7 +65,7 @@ async function writeHistoryFile(
     await fs.mkdir(path.dirname(filePath), { recursive: true });
     await fs.writeFile(filePath, history.join('\n'));
   } catch (error) {
-    console.error('Error writing shell history:', error);
+    debugLogger.error('Error writing shell history:', error);
   }
 }
 

packages/cli/src/ui/utils/ConsolePatcher.ts

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/* eslint-disable no-console */
+
 import util from 'node:util';
 import type { ConsoleMessageItem } from '../types.js';
 

packages/cli/src/ui/utils/InlineMarkdownRenderer.tsx

@@ -8,6 +8,7 @@ import React from 'react';
 import { Text } from 'ink';
 import { theme } from '../semantic-colors.js';
 import stringWidth from 'string-width';
+import { debugLogger } from '@google/gemini-cli-core';
 
 // Constants for Markdown parsing
 const BOLD_MARKER_LENGTH = 2; // For "**"
@@ -144,7 +145,7 @@ const RenderInlineInternal: React.FC<RenderInlineProps> = ({
         );
       }
     } catch (e) {
-      console.error('Error parsing inline markdown part:', fullMatch, e);
+      debugLogger.warn('Error parsing inline markdown part:', fullMatch, e);
       renderedNode = null;
     }
 

packages/cli/src/utils/errors.test.ts

@@ -4,9 +4,22 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { vi, type MockInstance } from 'vitest';
+import {
+  vi,
+  type MockInstance,
+  describe,
+  it,
+  expect,
+  beforeEach,
+  afterEach,
+} from 'vitest';
 import type { Config } from '@google/gemini-cli-core';
-import { OutputFormat, FatalInputError } from '@google/gemini-cli-core';
+import {
+  OutputFormat,
+  FatalInputError,
+  debugLogger,
+  coreEvents,
+} from '@google/gemini-cli-core';
 import {
   getErrorMessage,
   handleError,
@@ -14,6 +27,12 @@ import {
   handleCancellationError,
   handleMaxTurnsExceededError,
 } from './errors.js';
+import { runSyncCleanup } from './cleanup.js';
+
+// Mock the cleanup module
+vi.mock('./cleanup.js', () => ({
+  runSyncCleanup: vi.fn(),
+}));
 
 // Mock the core modules
 vi.mock('@google/gemini-cli-core', async (importOriginal) => {
@@ -63,6 +82,9 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
     JsonStreamEventType: {
       RESULT: 'result',
     },
+    coreEvents: {
+      emitFeedback: vi.fn(),
+    },
     FatalToolExecutionError: class extends Error {
       constructor(message: string) {
         super(message);
@@ -85,7 +107,10 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
 describe('errors', () => {
   let mockConfig: Config;
   let processExitSpy: MockInstance;
-  let consoleErrorSpy: MockInstance;
+  let debugLoggerErrorSpy: MockInstance;
+  let debugLoggerWarnSpy: MockInstance;
+  let coreEventsEmitFeedbackSpy: MockInstance;
+  let runSyncCleanupSpy: MockInstance;
 
   const TEST_SESSION_ID = 'test-session-123';
 
@@ -93,8 +118,19 @@ describe('errors', () => {
     // Reset mocks
     vi.clearAllMocks();
 
-    // Mock console.error
+    // Mock debugLogger
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
+    debugLoggerErrorSpy = vi
+      .spyOn(debugLogger, 'error')
+      .mockImplementation(() => {});
+    debugLoggerWarnSpy = vi
+      .spyOn(debugLogger, 'warn')
+      .mockImplementation(() => {});
+
+    // Mock coreEvents
+    coreEventsEmitFeedbackSpy = vi.mocked(coreEvents.emitFeedback);
+
+    // Mock runSyncCleanup
+    runSyncCleanupSpy = vi.mocked(runSyncCleanup);
 
     // Mock process.exit to throw instead of actually exiting
     processExitSpy = vi.spyOn(process, 'exit').mockImplementation((code) => {
@@ -110,7 +146,8 @@ describe('errors', () => {
   });
 
   afterEach(() => {
-    consoleErrorSpy.mockRestore();
+    debugLoggerErrorSpy.mockRestore();
+    debugLoggerWarnSpy.mockRestore();
     processExitSpy.mockRestore();
   });
 
@@ -141,14 +178,14 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.TEXT);
       });
 
-      it('should log error message and re-throw', () => {
+      it('should re-throw without logging to debugLogger', () => {
         const testError = new Error('Test error');
 
         expect(() => {
           handleError(testError, mockConfig);
         }).toThrow(testError);
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith('API Error: Test error');
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
       });
 
       it('should handle non-Error objects', () => {
@@ -157,8 +194,6 @@ describe('errors', () => {
         expect(() => {
           handleError(testError, mockConfig);
         }).toThrow(testError);
-
-        expect(consoleErrorSpy).toHaveBeenCalledWith('API Error: String error');
       });
     });
 
@@ -169,14 +204,16 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.JSON);
       });
 
-      it('should format error as JSON and exit with default code', () => {
+      it('should format error as JSON, emit feedback exactly once, and exit with default code', () => {
         const testError = new Error('Test error');
 
         expect(() => {
           handleError(testError, mockConfig);
         }).toThrow('process.exit called with code: 1');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -190,16 +227,20 @@ describe('errors', () => {
             2,
           ),
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
       });
 
-      it('should use custom error code when provided', () => {
+      it('should use custom error code when provided and only surface once', () => {
         const testError = new Error('Test error');
 
         expect(() => {
           handleError(testError, mockConfig, 42);
         }).toThrow('process.exit called with code: 42');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -213,16 +254,19 @@ describe('errors', () => {
             2,
           ),
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
       });
 
-      it('should extract exitCode from FatalError instances', () => {
+      it('should extract exitCode from FatalError instances and only surface once', () => {
         const fatalError = new FatalInputError('Fatal error');
 
         expect(() => {
           handleError(fatalError, mockConfig);
         }).toThrow('process.exit called with code: 42');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -236,6 +280,7 @@ describe('errors', () => {
             2,
           ),
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
       });
 
       it('should handle error with code property', () => {
@@ -259,7 +304,8 @@ describe('errors', () => {
           handleError(errorWithStatus, mockConfig);
         }).toThrow('process.exit called with code: 1'); // string codes become 1
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -283,12 +329,14 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.STREAM_JSON);
       });
 
-      it('should emit result event and exit', () => {
+      it('should emit result event, run cleanup, and exit', () => {
         const testError = new Error('Test error');
 
         expect(() => {
           handleError(testError, mockConfig);
         }).toThrow('process.exit called with code: 1');
+
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
       });
 
       it('should extract exitCode from FatalError instances', () => {
@@ -312,10 +360,10 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.TEXT);
       });
 
-      it('should log error message to stderr', () => {
+      it('should log error message to stderr (via debugLogger) for non-fatal', () => {
         handleToolError(toolName, toolError, mockConfig);
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
           'Error executing tool test-tool: Tool failed',
         );
       });
@@ -329,10 +377,24 @@ describe('errors', () => {
           'Custom display message',
         );
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
           'Error executing tool test-tool: Custom display message',
         );
       });
+
+      it('should emit feedback exactly once for fatal errors and not use debugLogger', () => {
+        expect(() => {
+          handleToolError(toolName, toolError, mockConfig, 'no_space_left');
+        }).toThrow('process.exit called with code: 54');
+
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
+          'Error executing tool test-tool: Tool failed',
+        );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
+      });
     });
 
     describe('in JSON mode', () => {
@@ -351,29 +413,32 @@ describe('errors', () => {
             'invalid_tool_params',
           );
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
             'Error executing tool test-tool: Tool failed',
           );
           // Should not exit for non-fatal errors
           expect(processExitSpy).not.toHaveBeenCalled();
+          expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
         });
 
         it('should not exit for file not found errors', () => {
           handleToolError(toolName, toolError, mockConfig, 'file_not_found');
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
             'Error executing tool test-tool: Tool failed',
           );
           expect(processExitSpy).not.toHaveBeenCalled();
+          expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
         });
 
         it('should not exit for permission denied errors', () => {
           handleToolError(toolName, toolError, mockConfig, 'permission_denied');
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
             'Error executing tool test-tool: Tool failed',
           );
           expect(processExitSpy).not.toHaveBeenCalled();
+          expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
         });
 
         it('should not exit for path not in workspace errors', () => {
@@ -384,10 +449,11 @@ describe('errors', () => {
             'path_not_in_workspace',
           );
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
             'Error executing tool test-tool: Tool failed',
           );
           expect(processExitSpy).not.toHaveBeenCalled();
+          expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
         });
 
         it('should prefer resultDisplay over error message', () => {
@@ -399,7 +465,7 @@ describe('errors', () => {
             'Display message',
           );
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
             'Error executing tool test-tool: Display message',
           );
           expect(processExitSpy).not.toHaveBeenCalled();
@@ -407,12 +473,14 @@ describe('errors', () => {
       });
 
       describe('fatal errors', () => {
-        it('should exit immediately for NO_SPACE_LEFT errors', () => {
+        it('should exit immediately for NO_SPACE_LEFT errors and only surface once', () => {
           expect(() => {
             handleToolError(toolName, toolError, mockConfig, 'no_space_left');
           }).toThrow('process.exit called with code: 54');
 
-          expect(consoleErrorSpy).toHaveBeenCalledWith(
+          expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+          expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+            'error',
             JSON.stringify(
               {
                 session_id: TEST_SESSION_ID,
@@ -426,6 +494,8 @@ describe('errors', () => {
               2,
             ),
           );
+          expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+          expect(runSyncCleanupSpy).toHaveBeenCalled();
         });
       });
     });
@@ -437,15 +507,17 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.STREAM_JSON);
       });
 
-      it('should emit result event and exit for fatal errors', () => {
+      it('should emit result event, run cleanup, and exit for fatal errors', () => {
         expect(() => {
           handleToolError(toolName, toolError, mockConfig, 'no_space_left');
         }).toThrow('process.exit called with code: 54');
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
+        expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled(); // Stream mode uses emitEvent
       });
 
       it('should log to stderr and not exit for non-fatal errors', () => {
         handleToolError(toolName, toolError, mockConfig, 'invalid_tool_params');
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(debugLoggerWarnSpy).toHaveBeenCalledWith(
           'Error executing tool test-tool: Tool failed',
         );
         expect(processExitSpy).not.toHaveBeenCalled();
@@ -461,12 +533,18 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.TEXT);
       });
 
-      it('should log cancellation message and exit with 130', () => {
+      it('should emit feedback exactly once, run cleanup, and exit with 130', () => {
         expect(() => {
           handleCancellationError(mockConfig);
         }).toThrow('process.exit called with code: 130');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith('Operation cancelled.');
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
+          'Operation cancelled.',
+        );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
       });
     });
 
@@ -477,12 +555,14 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.JSON);
       });
 
-      it('should format cancellation as JSON and exit with 130', () => {
+      it('should format cancellation as JSON, emit feedback once, and exit with 130', () => {
         expect(() => {
           handleCancellationError(mockConfig);
         }).toThrow('process.exit called with code: 130');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -496,6 +576,7 @@ describe('errors', () => {
             2,
           ),
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
       });
     });
 
@@ -510,6 +591,7 @@ describe('errors', () => {
         expect(() => {
           handleCancellationError(mockConfig);
         }).toThrow('process.exit called with code: 130');
+        expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
       });
     });
   });
@@ -522,14 +604,18 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.TEXT);
       });
 
-      it('should log max turns message and exit with 53', () => {
+      it('should emit feedback exactly once, run cleanup, and exit with 53', () => {
         expect(() => {
           handleMaxTurnsExceededError(mockConfig);
         }).toThrow('process.exit called with code: 53');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           'Reached max session turns for this session. Increase the number of turns by specifying maxSessionTurns in settings.json.',
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+        expect(runSyncCleanupSpy).toHaveBeenCalled();
       });
     });
 
@@ -540,12 +626,14 @@ describe('errors', () => {
         ).mockReturnValue(OutputFormat.JSON);
       });
 
-      it('should format max turns error as JSON and exit with 53', () => {
+      it('should format max turns error as JSON, emit feedback once, and exit with 53', () => {
         expect(() => {
           handleMaxTurnsExceededError(mockConfig);
         }).toThrow('process.exit called with code: 53');
 
-        expect(consoleErrorSpy).toHaveBeenCalledWith(
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledTimes(1);
+        expect(coreEventsEmitFeedbackSpy).toHaveBeenCalledWith(
+          'error',
           JSON.stringify(
             {
               session_id: TEST_SESSION_ID,
@@ -560,6 +648,7 @@ describe('errors', () => {
             2,
           ),
         );
+        expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
       });
     });
 
@@ -574,6 +663,7 @@ describe('errors', () => {
         expect(() => {
           handleMaxTurnsExceededError(mockConfig);
         }).toThrow('process.exit called with code: 53');
+        expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
       });
     });
   });

packages/cli/src/utils/errors.ts

@@ -16,6 +16,8 @@ import {
   FatalCancellationError,
   FatalToolExecutionError,
   isFatalToolError,
+  debugLogger,
+  coreEvents,
 } from '@google/gemini-cli-core';
 import { runSyncCleanup } from './cleanup.js';
 
@@ -103,11 +105,10 @@ export function handleError(
       config.getSessionId(),
     );
 
-    console.error(formattedError);
+    coreEvents.emitFeedback('error', formattedError);
     runSyncCleanup();
     process.exit(getNumericExitCode(errorCode));
   } else {
-    console.error(errorMessage);
     throw error;
   }
 }
@@ -155,16 +156,16 @@ export function handleToolError(
         errorType ?? toolExecutionError.exitCode,
         config.getSessionId(),
       );
-      console.error(formattedError);
+      coreEvents.emitFeedback('error', formattedError);
     } else {
-      console.error(errorMessage);
+      coreEvents.emitFeedback('error', errorMessage);
     }
     runSyncCleanup();
     process.exit(toolExecutionError.exitCode);
   }
 
   // Non-fatal: log and continue
-  console.error(errorMessage);
+  debugLogger.warn(errorMessage);
 }
 
 /**
@@ -196,11 +197,11 @@ export function handleCancellationError(config: Config): never {
       config.getSessionId(),
     );
 
-    console.error(formattedError);
+    coreEvents.emitFeedback('error', formattedError);
     runSyncCleanup();
     process.exit(cancellationError.exitCode);
   } else {
-    console.error(cancellationError.message);
+    coreEvents.emitFeedback('error', cancellationError.message);
     runSyncCleanup();
     process.exit(cancellationError.exitCode);
   }
@@ -237,11 +238,11 @@ export function handleMaxTurnsExceededError(config: Config): never {
       config.getSessionId(),
     );
 
-    console.error(formattedError);
+    coreEvents.emitFeedback('error', formattedError);
     runSyncCleanup();
     process.exit(maxTurnsError.exitCode);
   } else {
-    console.error(maxTurnsError.message);
+    coreEvents.emitFeedback('error', maxTurnsError.message);
     runSyncCleanup();
     process.exit(maxTurnsError.exitCode);
   }

packages/cli/src/utils/relaunch.test.ts

@@ -18,6 +18,19 @@ import { RELAUNCH_EXIT_CODE } from './processUtils.js';
 import type { ChildProcess } from 'node:child_process';
 import { spawn } from 'node:child_process';
 
+const mocks = vi.hoisted(() => ({
+  writeToStderr: vi.fn(),
+}));
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    writeToStderr: mocks.writeToStderr,
+  };
+});
+
 vi.mock('node:child_process', async (importOriginal) => {
   const actual = await importOriginal<typeof import('node:child_process')>();
   return {
@@ -33,23 +46,21 @@ import { relaunchAppInChildProcess, relaunchOnExitCode } from './relaunch.js';
 
 describe('relaunchOnExitCode', () => {
   let processExitSpy: MockInstance;
-  let consoleErrorSpy: MockInstance;
   let stdinResumeSpy: MockInstance;
 
   beforeEach(() => {
     processExitSpy = vi.spyOn(process, 'exit').mockImplementation(() => {
       throw new Error('PROCESS_EXIT_CALLED');
     });
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
     stdinResumeSpy = vi
       .spyOn(process.stdin, 'resume')
       .mockImplementation(() => process.stdin);
     vi.clearAllMocks();
+    mocks.writeToStderr.mockClear();
   });
 
   afterEach(() => {
     processExitSpy.mockRestore();
-    consoleErrorSpy.mockRestore();
     stdinResumeSpy.mockRestore();
   });
 
@@ -90,9 +101,10 @@ describe('relaunchOnExitCode', () => {
     );
 
     expect(runner).toHaveBeenCalledTimes(1);
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
-      'Fatal error: Failed to relaunch the CLI process.',
+      expect.stringContaining(
-      error,
+        'Fatal error: Failed to relaunch the CLI process.',
+      ),
     );
     expect(stdinResumeSpy).toHaveBeenCalled();
     expect(processExitSpy).toHaveBeenCalledWith(1);
@@ -101,7 +113,6 @@ describe('relaunchOnExitCode', () => {
 
 describe('relaunchAppInChildProcess', () => {
   let processExitSpy: MockInstance;
-  let consoleErrorSpy: MockInstance;
   let stdinPauseSpy: MockInstance;
   let stdinResumeSpy: MockInstance;
 
@@ -113,6 +124,7 @@ describe('relaunchAppInChildProcess', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    mocks.writeToStderr.mockClear();
 
     process.env = { ...originalEnv };
     delete process.env['GEMINI_CLI_NO_RELAUNCH'];
@@ -124,7 +136,6 @@ describe('relaunchAppInChildProcess', () => {
     processExitSpy = vi.spyOn(process, 'exit').mockImplementation(() => {
       throw new Error('PROCESS_EXIT_CALLED');
     });
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
     stdinPauseSpy = vi
       .spyOn(process.stdin, 'pause')
       .mockImplementation(() => process.stdin);
@@ -140,7 +151,6 @@ describe('relaunchAppInChildProcess', () => {
     process.execPath = originalExecPath;
 
     processExitSpy.mockRestore();
-    consoleErrorSpy.mockRestore();
     stdinPauseSpy.mockRestore();
     stdinResumeSpy.mockRestore();
   });

packages/cli/src/utils/relaunch.ts

@@ -6,6 +6,7 @@
 
 import { spawn } from 'node:child_process';
 import { RELAUNCH_EXIT_CODE } from './processUtils.js';
+import { writeToStderr } from '@google/gemini-cli-core';
 
 export async function relaunchOnExitCode(runner: () => Promise<number>) {
   while (true) {
@@ -17,7 +18,11 @@ export async function relaunchOnExitCode(runner: () => Promise<number>) {
       }
     } catch (error) {
       process.stdin.resume();
-      console.error('Fatal error: Failed to relaunch the CLI process.', error);
+      const errorMessage =
+        error instanceof Error ? (error.stack ?? error.message) : String(error);
+      writeToStderr(
+        `Fatal error: Failed to relaunch the CLI process.\n${errorMessage}\n`,
+      );
       process.exit(1);
     }
   }

packages/cli/src/utils/sandbox.ts

@@ -251,7 +251,9 @@ export async function start_sandbox(
     }
 
     // stop if image is missing
-    if (!(await ensureSandboxImageIsPresent(config.command, image))) {
+    if (
+      !(await ensureSandboxImageIsPresent(config.command, image, cliConfig))
+    ) {
       const remedy =
         image === LOCAL_DEV_SANDBOX_IMAGE_NAME
           ? 'Try running `npm run build:all` or `npm run build:sandbox` under the gemini-cli repo to build it locally, or check the image name and your network connection.'
@@ -718,8 +720,12 @@ async function imageExists(sandbox: string, image: string): Promise<boolean> {
   });
 }
 
-async function pullImage(sandbox: string, image: string): Promise<boolean> {
+async function pullImage(
-  console.info(`Attempting to pull image ${image} using ${sandbox}...`);
+  sandbox: string,
+  image: string,
+  cliConfig?: Config,
+): Promise<boolean> {
+  debugLogger.debug(`Attempting to pull image ${image} using ${sandbox}...`);
   return new Promise((resolve) => {
     const args = ['pull', image];
     const pullProcess = spawn(sandbox, args, { stdio: 'pipe' });
@@ -727,11 +733,14 @@ async function pullImage(sandbox: string, image: string): Promise<boolean> {
     let stderrData = '';
 
     const onStdoutData = (data: Buffer) => {
-      console.info(data.toString().trim()); // Show pull progress
+      if (cliConfig?.getDebugMode() || process.env['DEBUG']) {
+        debugLogger.log(data.toString().trim()); // Show pull progress
+      }
     };
 
     const onStderrData = (data: Buffer) => {
       stderrData += data.toString();
+      // eslint-disable-next-line no-console
       console.error(data.toString().trim()); // Show pull errors/info from the command itself
     };
 
@@ -745,7 +754,7 @@ async function pullImage(sandbox: string, image: string): Promise<boolean> {
 
     const onClose = (code: number | null) => {
       if (code === 0) {
-        console.info(`Successfully pulled image ${image}.`);
+        debugLogger.log(`Successfully pulled image ${image}.`);
         cleanup();
         resolve(true);
       } else {
@@ -788,6 +797,7 @@ async function pullImage(sandbox: string, image: string): Promise<boolean> {
 async function ensureSandboxImageIsPresent(
   sandbox: string,
   image: string,
+  cliConfig?: Config,
 ): Promise<boolean> {
   debugLogger.log(`Checking for sandbox image: ${image}`);
   if (await imageExists(sandbox, image)) {
@@ -801,7 +811,7 @@ async function ensureSandboxImageIsPresent(
     return false;
   }
 
-  if (await pullImage(sandbox, image)) {
+  if (await pullImage(sandbox, image, cliConfig)) {
     // After attempting to pull, check again to be certain
     if (await imageExists(sandbox, image)) {
       debugLogger.log(`Sandbox image ${image} is now available after pulling.`);

packages/cli/src/utils/sessionCleanup.integration.test.ts

@@ -7,7 +7,11 @@
 import { describe, it, expect, vi } from 'vitest';
 import { cleanupExpiredSessions } from './sessionCleanup.js';
 import type { Settings } from '../config/settings.js';
-import { SESSION_FILE_PREFIX, type Config } from '@google/gemini-cli-core';
+import {
+  SESSION_FILE_PREFIX,
+  type Config,
+  debugLogger,
+} from '@google/gemini-cli-core';
 
 // Create a mock config for integration testing
 function createTestConfig(): Config {
@@ -112,7 +116,7 @@ describe('Session Cleanup Integration', () => {
   });
 
   it('should validate configuration and fail gracefully', async () => {
-    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
+    const errorSpy = vi.spyOn(debugLogger, 'warn').mockImplementation(() => {});
     const config = createTestConfig();
 
     const settings: Settings = {

packages/cli/src/utils/sessionCleanup.test.ts

@@ -100,6 +100,8 @@ function createTestSessions(): SessionInfo[] {
 describe('Session Cleanup', () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    vi.spyOn(debugLogger, 'error').mockImplementation(() => {});
+    vi.spyOn(debugLogger, 'warn').mockImplementation(() => {});
     // By default, return all test sessions as valid
     const sessions = createTestSessions();
     mockGetAllSessionFiles.mockResolvedValue(
@@ -154,20 +156,16 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       const result = await cleanupExpiredSessions(config, settings);
 
       expect(result.disabled).toBe(true);
       expect(result.scanned).toBe(0);
       expect(result.deleted).toBe(0);
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         expect.stringContaining(
           'Session cleanup disabled: Error: Invalid retention period format',
         ),
       );
-
-      errorSpy.mockRestore();
     });
 
     it('should delete sessions older than maxAge', async () => {
@@ -338,8 +336,6 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       // Mock getSessionFiles to throw an error
       mockGetAllSessionFiles.mockRejectedValue(
         new Error('Directory access failed'),
@@ -349,11 +345,9 @@ describe('Session Cleanup', () => {
 
       expect(result.disabled).toBe(false);
       expect(result.failed).toBe(1);
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         'Session cleanup failed: Directory access failed',
       );
-
-      errorSpy.mockRestore();
     });
 
     it('should respect minRetention configuration', async () => {
@@ -979,21 +973,17 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       const result = await cleanupExpiredSessions(config, settings);
 
       expect(result.disabled).toBe(true);
       expect(result.scanned).toBe(0);
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         expect.stringContaining(
           input === '0d'
             ? 'Invalid retention period: 0d. Value must be greater than 0'
             : `Invalid retention period format: ${input}`,
         ),
       );
-
-      errorSpy.mockRestore();
     });
 
     // Test special case - empty string
@@ -1010,18 +1000,14 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       const result = await cleanupExpiredSessions(config, settings);
 
       expect(result.disabled).toBe(true);
       expect(result.scanned).toBe(0);
       // Empty string means no valid retention method specified
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         expect.stringContaining('Either maxAge or maxCount must be specified'),
       );
-
-      errorSpy.mockRestore();
     });
 
     // Test edge cases
@@ -1082,17 +1068,13 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       const result = await cleanupExpiredSessions(config, settings);
 
       expect(result.disabled).toBe(true);
       expect(result.scanned).toBe(0);
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         expect.stringContaining('Either maxAge or maxCount must be specified'),
       );
-
-      errorSpy.mockRestore();
     });
 
     it('should validate maxCount range', async () => {
@@ -1108,17 +1090,13 @@ describe('Session Cleanup', () => {
         },
       };
 
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
-
       const result = await cleanupExpiredSessions(config, settings);
 
       expect(result.disabled).toBe(true);
       expect(result.scanned).toBe(0);
-      expect(errorSpy).toHaveBeenCalledWith(
+      expect(debugLogger.warn).toHaveBeenCalledWith(
         expect.stringContaining('maxCount must be at least 1'),
       );
-
-      errorSpy.mockRestore();
     });
 
     describe('maxAge format validation', () => {
@@ -1135,21 +1113,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format: 30'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject invalid maxAge format - invalid unit', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1163,21 +1134,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format: 30x'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject invalid maxAge format - no number', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1191,21 +1155,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format: d'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject invalid maxAge format - decimal number', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1219,21 +1176,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format: 1.5d'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject invalid maxAge format - negative number', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1247,21 +1197,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format: -5d'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should accept valid maxAge format - hours', async () => {
         const config = createMockConfig();
         const settings: Settings = {
@@ -1362,23 +1305,16 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining(
             'maxAge cannot be less than minRetention (1d)',
           ),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject maxAge less than custom minRetention', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1393,23 +1329,16 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining(
             'maxAge cannot be less than minRetention (3d)',
           ),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should accept maxAge equal to minRetention', async () => {
         const config = createMockConfig();
         const settings: Settings = {
@@ -1537,21 +1466,14 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('maxCount must be at least 1'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should accept valid maxCount in normal range', async () => {
         const config = createMockConfig();
         const settings: Settings = {
@@ -1611,22 +1533,15 @@ describe('Session Cleanup', () => {
           },
         };
 
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
         // Should fail on first validation error (maxAge format)
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format'),
         );
-
-        errorSpy.mockRestore();
       });
-
       it('should reject if maxAge is invalid even when maxCount is valid', async () => {
         const config = createMockConfig({
           getDebugMode: vi.fn().mockReturnValue(true),
@@ -1642,20 +1557,14 @@ describe('Session Cleanup', () => {
         };
 
         // The validation logic rejects invalid maxAge format even if maxCount is valid
-        const errorSpy = vi
-          .spyOn(console, 'error')
-          .mockImplementation(() => {});
-
         const result = await cleanupExpiredSessions(config, settings);
 
         // Should reject due to invalid maxAge format
         expect(result.disabled).toBe(true);
         expect(result.scanned).toBe(0);
-        expect(errorSpy).toHaveBeenCalledWith(
+        expect(debugLogger.warn).toHaveBeenCalledWith(
           expect.stringContaining('Invalid retention period format'),
         );
-
-        errorSpy.mockRestore();
       });
     });
 

packages/cli/src/utils/sessionCleanup.ts

@@ -62,7 +62,7 @@ export async function cleanupExpiredSessions(
     );
     if (validationErrorMessage) {
       // Log validation errors to console for visibility
-      console.error(`Session cleanup disabled: ${validationErrorMessage}`);
+      debugLogger.warn(`Session cleanup disabled: ${validationErrorMessage}`);
       return { ...result, disabled: true };
     }
 
@@ -114,7 +114,7 @@ export async function cleanupExpiredSessions(
               : sessionToDelete.sessionInfo.id;
           const errorMessage =
             error instanceof Error ? error.message : 'Unknown error';
-          console.error(
+          debugLogger.warn(
             `Failed to delete session ${sessionId}: ${errorMessage}`,
           );
           result.failed++;
@@ -133,7 +133,7 @@ export async function cleanupExpiredSessions(
     // Global error handler - don't let cleanup failures break startup
     const errorMessage =
       error instanceof Error ? error.message : 'Unknown error';
-    console.error(`Session cleanup failed: ${errorMessage}`);
+    debugLogger.warn(`Session cleanup failed: ${errorMessage}`);
     result.failed++;
   }
 
@@ -273,7 +273,7 @@ function validateRetentionConfig(
     } catch (error) {
       // If minRetention format is invalid, fall back to default
       if (config.getDebugMode()) {
-        console.error(`Failed to parse minRetention: ${error}`);
+        debugLogger.warn(`Failed to parse minRetention: ${error}`);
       }
       minRetentionMs = parseRetentionPeriod(DEFAULT_MIN_RETENTION);
     }

packages/cli/src/utils/sessions.test.ts

@@ -10,6 +10,11 @@ import { ChatRecordingService } from '@google/gemini-cli-core';
 import { listSessions, deleteSession } from './sessions.js';
 import { SessionSelector, type SessionInfo } from './sessionUtils.js';
 
+const mocks = vi.hoisted(() => ({
+  writeToStdout: vi.fn(),
+  writeToStderr: vi.fn(),
+}));
+
 // Mock the SessionSelector and ChatRecordingService
 vi.mock('./sessionUtils.js', () => ({
   SessionSelector: vi.fn(),
@@ -22,13 +27,14 @@ vi.mock('@google/gemini-cli-core', async () => {
     ...actual,
     ChatRecordingService: vi.fn(),
     generateSummary: vi.fn().mockResolvedValue(undefined),
+    writeToStdout: mocks.writeToStdout,
+    writeToStderr: mocks.writeToStderr,
   };
 });
 
 describe('listSessions', () => {
   let mockConfig: Config;
   let mockListSessions: ReturnType<typeof vi.fn>;
-  let consoleLogSpy: ReturnType<typeof vi.spyOn>;
 
   beforeEach(() => {
     // Create mock config
@@ -49,14 +55,12 @@ describe('listSessions', () => {
           listSessions: mockListSessions,
         }) as unknown as InstanceType<typeof SessionSelector>,
     );
-
-    // Spy on console.log
-    consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
   });
 
   afterEach(() => {
     vi.clearAllMocks();
-    consoleLogSpy.mockRestore();
+    mocks.writeToStdout.mockClear();
+    mocks.writeToStderr.mockClear();
   });
 
   it('should display message when no previous sessions were found', async () => {
@@ -68,7 +72,7 @@ describe('listSessions', () => {
 
     // Assert
     expect(mockListSessions).toHaveBeenCalledOnce();
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       'No previous sessions found for this project.',
     );
   });
@@ -127,32 +131,32 @@ describe('listSessions', () => {
     expect(mockListSessions).toHaveBeenCalledOnce();
 
     // Check that the header was displayed
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       '\nAvailable sessions for this project (3):\n',
     );
 
     // Check that each session was logged
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('1. First user message'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('[session-1]'),
     );
 
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('2. Second user message'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('[session-2]'),
     );
 
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('3. Current session'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining(', current)'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('[current-session-id]'),
     );
   });
@@ -209,7 +213,7 @@ describe('listSessions', () => {
 
     // Assert
     // Get all the session log calls (skip the header)
-    const sessionCalls = consoleLogSpy.mock.calls.filter(
+    const sessionCalls = mocks.writeToStdout.mock.calls.filter(
       (call): call is [string] =>
         typeof call[0] === 'string' &&
         call[0].includes('[session-') &&
@@ -246,13 +250,13 @@ describe('listSessions', () => {
     await listSessions(mockConfig);
 
     // Assert
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('1. Test message'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('some time ago'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('[abc123def456]'),
     );
   });
@@ -281,13 +285,13 @@ describe('listSessions', () => {
     await listSessions(mockConfig);
 
     // Assert
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       '\nAvailable sessions for this project (1):\n',
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('1. Only session'),
     );
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining(', current)'),
     );
   });
@@ -318,10 +322,10 @@ describe('listSessions', () => {
     await listSessions(mockConfig);
 
     // Assert: Should show the summary (displayName), not the first user message
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('1. Add dark mode to the app'),
     );
-    expect(consoleLogSpy).not.toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).not.toHaveBeenCalledWith(
       expect.stringContaining('How do I add dark mode to my React application'),
     );
   });
@@ -331,8 +335,6 @@ describe('deleteSession', () => {
   let mockConfig: Config;
   let mockListSessions: ReturnType<typeof vi.fn>;
   let mockDeleteSession: ReturnType<typeof vi.fn>;
-  let consoleLogSpy: ReturnType<typeof vi.spyOn>;
-  let consoleErrorSpy: ReturnType<typeof vi.spyOn>;
 
   beforeEach(() => {
     // Create mock config
@@ -362,16 +364,10 @@ describe('deleteSession', () => {
           deleteSession: mockDeleteSession,
         }) as unknown as InstanceType<typeof ChatRecordingService>,
     );
-
-    // Spy on console methods
-    consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
   });
 
   afterEach(() => {
     vi.clearAllMocks();
-    consoleLogSpy.mockRestore();
-    consoleErrorSpy.mockRestore();
   });
 
   it('should display error when no sessions are found', async () => {
@@ -383,7 +379,7 @@ describe('deleteSession', () => {
 
     // Assert
     expect(mockListSessions).toHaveBeenCalledOnce();
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'No sessions found for this project.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -416,10 +412,10 @@ describe('deleteSession', () => {
     // Assert
     expect(mockListSessions).toHaveBeenCalledOnce();
     expect(mockDeleteSession).toHaveBeenCalledWith('session-file-123');
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       'Deleted session 1: Test session (some time ago)',
     );
-    expect(consoleErrorSpy).not.toHaveBeenCalled();
+    expect(mocks.writeToStderr).not.toHaveBeenCalled();
   });
 
   it('should delete session by index', async () => {
@@ -463,7 +459,7 @@ describe('deleteSession', () => {
     // Assert
     expect(mockListSessions).toHaveBeenCalledOnce();
     expect(mockDeleteSession).toHaveBeenCalledWith('session-file-2');
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       'Deleted session 2: Second session (some time ago)',
     );
   });
@@ -492,7 +488,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, 'invalid-id');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Invalid session identifier "invalid-id". Use --list-sessions to see available sessions.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -522,7 +518,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, '999');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Invalid session identifier "999". Use --list-sessions to see available sessions.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -552,7 +548,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, '0');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Invalid session identifier "0". Use --list-sessions to see available sessions.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -582,7 +578,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, '1');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Cannot delete the current active session.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -612,7 +608,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, 'current-session-id');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Cannot delete the current active session.',
     );
     expect(mockDeleteSession).not.toHaveBeenCalled();
@@ -646,7 +642,7 @@ describe('deleteSession', () => {
 
     // Assert
     expect(mockDeleteSession).toHaveBeenCalledWith('session-file-1');
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Failed to delete session: File deletion failed',
     );
   });
@@ -679,7 +675,7 @@ describe('deleteSession', () => {
     await deleteSession(mockConfig, '1');
 
     // Assert
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStderr).toHaveBeenCalledWith(
       'Failed to delete session: Unknown error',
     );
   });
@@ -737,7 +733,7 @@ describe('deleteSession', () => {
 
     // Assert
     expect(mockDeleteSession).toHaveBeenCalledWith('session-file-1');
-    expect(consoleLogSpy).toHaveBeenCalledWith(
+    expect(mocks.writeToStdout).toHaveBeenCalledWith(
       expect.stringContaining('Oldest session'),
     );
   });

packages/cli/src/utils/sessions.ts

@@ -7,6 +7,8 @@
 import {
   ChatRecordingService,
   generateSummary,
+  writeToStderr,
+  writeToStdout,
   type Config,
 } from '@google/gemini-cli-core';
 import {
@@ -23,11 +25,13 @@ export async function listSessions(config: Config): Promise<void> {
   const sessions = await sessionSelector.listSessions();
 
   if (sessions.length === 0) {
-    console.log('No previous sessions found for this project.');
+    writeToStdout('No previous sessions found for this project.');
     return;
   }
 
-  console.log(`\nAvailable sessions for this project (${sessions.length}):\n`);
+  writeToStdout(
+    `\nAvailable sessions for this project (${sessions.length}):\n`,
+  );
 
   sessions
     .sort(
@@ -41,8 +45,8 @@ export async function listSessions(config: Config): Promise<void> {
         session.displayName.length > 100
           ? session.displayName.slice(0, 97) + '...'
           : session.displayName;
-      console.log(
+      writeToStdout(
-        `  ${index + 1}. ${title} (${time}${current}) [${session.id}]`,
+        `  ${index + 1}. ${title} (${time}${current}) [${session.id}]\n`,
       );
     });
 }
@@ -55,7 +59,7 @@ export async function deleteSession(
   const sessions = await sessionSelector.listSessions();
 
   if (sessions.length === 0) {
-    console.error('No sessions found for this project.');
+    writeToStderr('No sessions found for this project.');
     return;
   }
 
@@ -76,7 +80,7 @@ export async function deleteSession(
     // Parse session index
     const index = parseInt(sessionIndex, 10);
     if (isNaN(index) || index < 1 || index > sessions.length) {
-      console.error(
+      writeToStderr(
         `Invalid session identifier "${sessionIndex}". Use --list-sessions to see available sessions.`,
       );
       return;
@@ -86,7 +90,7 @@ export async function deleteSession(
 
   // Prevent deleting the current session
   if (sessionToDelete.isCurrentSession) {
-    console.error('Cannot delete the current active session.');
+    writeToStderr('Cannot delete the current active session.');
     return;
   }
 
@@ -96,11 +100,11 @@ export async function deleteSession(
     chatRecordingService.deleteSession(sessionToDelete.file);
 
     const time = formatRelativeTime(sessionToDelete.lastUpdated);
-    console.log(
+    writeToStdout(
       `Deleted session ${sessionToDelete.index}: ${sessionToDelete.firstUserMessage} (${time})`,
     );
   } catch (error) {
-    console.error(
+    writeToStderr(
       `Failed to delete session: ${error instanceof Error ? error.message : 'Unknown error'}`,
     );
   }

packages/cli/src/validateNonInterActiveAuth.test.ts

@@ -21,6 +21,7 @@ import {
   makeFakeConfig,
   debugLogger,
   ExitCodes,
+  coreEvents,
 } from '@google/gemini-cli-core';
 import type { Config } from '@google/gemini-cli-core';
 import * as auth from './config/auth.js';
@@ -36,8 +37,8 @@ describe('validateNonInterActiveAuth', () => {
   let originalEnvGeminiApiKey: string | undefined;
   let originalEnvVertexAi: string | undefined;
   let originalEnvGcp: string | undefined;
-  let consoleErrorSpy: ReturnType<typeof vi.spyOn>;
   let debugLoggerErrorSpy: ReturnType<typeof vi.spyOn>;
+  let coreEventsEmitFeedbackSpy: MockInstance;
   let processExitSpy: MockInstance;
   let refreshAuthMock: Mock;
   let mockSettings: LoadedSettings;
@@ -49,10 +50,12 @@ describe('validateNonInterActiveAuth', () => {
     delete process.env['GEMINI_API_KEY'];
     delete process.env['GOOGLE_GENAI_USE_VERTEXAI'];
     delete process.env['GOOGLE_GENAI_USE_GCA'];
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
     debugLoggerErrorSpy = vi
       .spyOn(debugLogger, 'error')
       .mockImplementation(() => {});
+    coreEventsEmitFeedbackSpy = vi
+      .spyOn(coreEvents, 'emitFeedback')
+      .mockImplementation(() => {});
     processExitSpy = vi
       .spyOn(process, 'exit')
       .mockImplementation((code?: string | number | null | undefined) => {
@@ -302,6 +305,7 @@ describe('validateNonInterActiveAuth', () => {
 
     expect(validateAuthMethodSpy).not.toHaveBeenCalled();
     expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+    expect(coreEventsEmitFeedbackSpy).not.toHaveBeenCalled();
     expect(processExitSpy).not.toHaveBeenCalled();
     // We still expect refreshAuth to be called with the (invalid) type
     expect(refreshAuthMock).toHaveBeenCalledWith('invalid-auth-type');
@@ -404,7 +408,8 @@ describe('validateNonInterActiveAuth', () => {
       expect(thrown?.message).toBe(
         `process.exit(${ExitCodes.FATAL_AUTHENTICATION_ERROR}) called`,
       );
-      const errorArg = consoleErrorSpy.mock.calls[0]?.[0] as string;
+      // Checking coreEventsEmitFeedbackSpy arguments
+      const errorArg = coreEventsEmitFeedbackSpy.mock.calls[0]?.[1] as string;
       const payload = JSON.parse(errorArg);
       expect(payload.error.type).toBe('Error');
       expect(payload.error.code).toBe(ExitCodes.FATAL_AUTHENTICATION_ERROR);
@@ -439,7 +444,8 @@ describe('validateNonInterActiveAuth', () => {
         `process.exit(${ExitCodes.FATAL_AUTHENTICATION_ERROR}) called`,
       );
       {
-        const errorArg = consoleErrorSpy.mock.calls[0]?.[0] as string;
+        // Checking coreEventsEmitFeedbackSpy arguments
+        const errorArg = coreEventsEmitFeedbackSpy.mock.calls[0]?.[1] as string;
         const payload = JSON.parse(errorArg);
         expect(payload.error.type).toBe('Error');
         expect(payload.error.code).toBe(ExitCodes.FATAL_AUTHENTICATION_ERROR);
@@ -477,7 +483,8 @@ describe('validateNonInterActiveAuth', () => {
         `process.exit(${ExitCodes.FATAL_AUTHENTICATION_ERROR}) called`,
       );
       {
-        const errorArg = consoleErrorSpy.mock.calls[0]?.[0] as string;
+        // Checking coreEventsEmitFeedbackSpy arguments
+        const errorArg = coreEventsEmitFeedbackSpy.mock.calls[0]?.[1] as string;
         const payload = JSON.parse(errorArg);
         expect(payload.error.type).toBe('Error');
         expect(payload.error.code).toBe(ExitCodes.FATAL_AUTHENTICATION_ERROR);

packages/core/src/confirmation-bus/message-bus.ts

@@ -14,6 +14,7 @@ import {
   type HookPolicyDecision,
 } from './types.js';
 import { safeJsonStringify } from '../utils/safeJsonStringify.js';
+import { debugLogger } from '../utils/debugLogger.js';
 
 export class MessageBus extends EventEmitter {
   constructor(
@@ -45,7 +46,7 @@ export class MessageBus extends EventEmitter {
 
   async publish(message: Message): Promise<void> {
     if (this.debug) {
-      console.debug(`[MESSAGE_BUS] publish: ${safeJsonStringify(message)}`);
+      debugLogger.debug(`[MESSAGE_BUS] publish: ${safeJsonStringify(message)}`);
     }
     try {
       if (!this.isValidMessage(message)) {

packages/core/src/ide/ide-client.ts

@@ -30,7 +30,7 @@ const logger = {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   debug: (...args: any[]) => debugLogger.debug('[DEBUG] [IDEClient]', ...args),
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  error: (...args: any[]) => console.error('[ERROR] [IDEClient]', ...args),
+  error: (...args: any[]) => debugLogger.error('[ERROR] [IDEClient]', ...args),
 };
 
 export type DiffUpdateResult =

packages/core/src/mcp/oauth-utils.ts

@@ -418,7 +418,10 @@ export class OAuthUtils {
         return payload.exp * 1000; // Convert seconds to milliseconds
       }
     } catch (e) {
-      console.error('Failed to parse ID token for expiry time with error:', e);
+      debugLogger.error(
+        'Failed to parse ID token for expiry time with error:',
+        e,
+      );
     }
 
     // Return undefined if try block fails or 'exp' is missing/invalid

packages/core/src/mcp/token-storage/keychain-token-storage.ts

@@ -324,7 +324,11 @@ export class KeychainTokenStorage
         .filter((cred) => cred.account.startsWith(SECRET_PREFIX))
         .map((cred) => cred.account.substring(SECRET_PREFIX.length));
     } catch (error) {
-      console.error('Failed to list secrets from keychain:', error);
+      coreEvents.emitFeedback(
+        'error',
+        'Failed to list secrets from keychain',
+        error,
+      );
       return [];
     }
   }

packages/core/src/policy/config.ts

@@ -28,6 +28,7 @@ import {
 } from '../confirmation-bus/types.js';
 import { type MessageBus } from '../confirmation-bus/message-bus.js';
 import { coreEvents } from '../utils/events.js';
+import { debugLogger } from '../utils/debugLogger.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -312,7 +313,7 @@ export function createPolicyUpdater(
             existingData = toml.parse(fileContent) as { rule?: TomlRule[] };
           } catch (error) {
             if ((error as NodeJS.ErrnoException).code !== 'ENOENT') {
-              console.warn(
+              debugLogger.warn(
                 `Failed to parse ${policyFile}, overwriting with new policy.`,
                 error,
               );

packages/core/src/routing/strategies/compositeStrategy.test.ts

@@ -14,6 +14,14 @@ import type {
 } from '../routingStrategy.js';
 import type { Config } from '../../config/config.js';
 import type { BaseLlmClient } from '../../core/baseLlmClient.js';
+import { debugLogger } from '../../utils/debugLogger.js';
+import { coreEvents } from '../../utils/events.js';
+
+vi.mock('../../utils/debugLogger.js', () => ({
+  debugLogger: {
+    warn: vi.fn(),
+  },
+}));
 
 describe('CompositeStrategy', () => {
   let mockContext: RoutingContext;
@@ -22,6 +30,7 @@ describe('CompositeStrategy', () => {
   let mockStrategy1: RoutingStrategy;
   let mockStrategy2: RoutingStrategy;
   let mockTerminalStrategy: TerminalStrategy;
+  let emitFeedbackSpy: ReturnType<typeof vi.spyOn>;
 
   beforeEach(() => {
     vi.clearAllMocks();
@@ -30,6 +39,8 @@ describe('CompositeStrategy', () => {
     mockConfig = {} as Config;
     mockBaseLlmClient = {} as BaseLlmClient;
 
+    emitFeedbackSpy = vi.spyOn(coreEvents, 'emitFeedback');
+
     mockStrategy1 = {
       name: 'strategy1',
       route: vi.fn().mockResolvedValue(null),
@@ -112,9 +123,6 @@ describe('CompositeStrategy', () => {
   });
 
   it('should handle errors in non-terminal strategies and continue', async () => {
-    const consoleErrorSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
     vi.spyOn(mockStrategy1, 'route').mockRejectedValue(
       new Error('Strategy 1 failed'),
     );
@@ -130,18 +138,14 @@ describe('CompositeStrategy', () => {
       mockBaseLlmClient,
     );
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLogger.warn).toHaveBeenCalledWith(
       "[Routing] Strategy 'strategy1' failed. Continuing to next strategy. Error:",
       expect.any(Error),
     );
     expect(result.model).toBe('terminal-model');
-    consoleErrorSpy.mockRestore();
   });
 
   it('should re-throw an error from the terminal strategy', async () => {
-    const consoleErrorSpy = vi
-      .spyOn(console, 'error')
-      .mockImplementation(() => {});
     const terminalError = new Error('Terminal strategy failed');
     vi.spyOn(mockTerminalStrategy, 'route').mockRejectedValue(terminalError);
 
@@ -151,11 +155,11 @@ describe('CompositeStrategy', () => {
       composite.route(mockContext, mockConfig, mockBaseLlmClient),
     ).rejects.toThrow(terminalError);
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(emitFeedbackSpy).toHaveBeenCalledWith(
+      'error',
       "[Routing] Critical Error: Terminal strategy 'terminal' failed. Routing cannot proceed. Error:",
       terminalError,
     );
-    consoleErrorSpy.mockRestore();
   });
 
   it('should correctly finalize the decision metadata', async () => {

packages/core/src/routing/strategies/compositeStrategy.ts

@@ -6,6 +6,8 @@
 
 import type { Config } from '../../config/config.js';
 import type { BaseLlmClient } from '../../core/baseLlmClient.js';
+import { debugLogger } from '../../utils/debugLogger.js';
+import { coreEvents } from '../../utils/events.js';
 import type {
   RoutingContext,
   RoutingDecision,
@@ -59,7 +61,7 @@ export class CompositeStrategy implements TerminalStrategy {
           return this.finalizeDecision(decision, startTime);
         }
       } catch (error) {
-        console.error(
+        debugLogger.warn(
           `[Routing] Strategy '${strategy.name}' failed. Continuing to next strategy. Error:`,
           error,
         );
@@ -76,7 +78,8 @@ export class CompositeStrategy implements TerminalStrategy {
 
       return this.finalizeDecision(decision, startTime);
     } catch (error) {
-      console.error(
+      coreEvents.emitFeedback(
+        'error',
         `[Routing] Critical Error: Terminal strategy '${terminalStrategy.name}' failed. Routing cannot proceed. Error:`,
         error,
       );

packages/core/src/telemetry/clearcut-logger/clearcut-logger.ts

@@ -277,7 +277,7 @@ export class ClearcutLogger {
       this.enqueueHelper(event);
     } catch (error) {
       if (this.config?.getDebugMode()) {
-        console.error('ClearcutLogger: Failed to enqueue log event.', error);
+        debugLogger.warn('ClearcutLogger: Failed to enqueue log event.', error);
       }
     }
   }
@@ -301,9 +301,7 @@ export class ClearcutLogger {
         this.enqueueHelper(event);
       });
     } catch (error) {
-      if (this.config?.getDebugMode()) {
+      debugLogger.warn('ClearcutLogger: Failed to enqueue log event.', error);
-        console.error('ClearcutLogger: Failed to enqueue log event.', error);
-      }
     }
   }
 
@@ -435,7 +433,7 @@ export class ClearcutLogger {
         };
       } else {
         if (this.config?.getDebugMode()) {
-          console.error(
+          debugLogger.warn(
             `Error flushing log events: HTTP ${response.status}: ${response.statusText}`,
           );
         }
@@ -445,7 +443,7 @@ export class ClearcutLogger {
       }
     } catch (e: unknown) {
       if (this.config?.getDebugMode()) {
-        console.error('Error flushing log events:', e as Error);
+        debugLogger.warn('Error flushing log events:', e as Error);
       }
 
       // Re-queue failed events for retry

packages/core/src/telemetry/sdk.ts

@@ -157,7 +157,6 @@ export async function initializeTelemetry(
     ) {
       const message = `Telemetry credentials have changed (from ${activeTelemetryEmail} to ${credentials.client_email}), but telemetry cannot be re-initialized in this process. Please restart the CLI to use the new account for telemetry.`;
       debugLogger.error(message);
-      console.error(message);
     }
     return;
   }
@@ -309,7 +308,7 @@ export async function initializeTelemetry(
     initializeMetrics(config);
     void flushTelemetryBuffer();
   } catch (error) {
-    console.error('Error starting OpenTelemetry SDK:', error);
+    debugLogger.error('Error starting OpenTelemetry SDK:', error);
   }
 
   // Note: We don't use process.on('exit') here because that callback is synchronous
@@ -343,7 +342,7 @@ export async function flushTelemetry(config: Config): Promise<void> {
       debugLogger.log('OpenTelemetry SDK flushed successfully.');
     }
   } catch (error) {
-    console.error('Error flushing SDK:', error);
+    debugLogger.error('Error flushing SDK:', error);
   }
 }
 
@@ -361,7 +360,7 @@ export async function shutdownTelemetry(
       debugLogger.log('OpenTelemetry SDK shut down successfully.');
     }
   } catch (error) {
-    console.error('Error shutting down SDK:', error);
+    debugLogger.error('Error shutting down SDK:', error);
   } finally {
     telemetryInitialized = false;
     sdk = undefined;

packages/core/src/tools/edit.test.ts

@@ -1159,7 +1159,7 @@ describe('EditTool', () => {
             result.returnDisplay.diffStat?.model_removed_lines,
           );
         } else if (result.error) {
-          console.error(`Edit failed for ${file.path}:`, result.error);
+          throw result.error;
         }
       }
 

packages/core/src/tools/memoryTool.ts

@@ -277,9 +277,6 @@ class MemoryToolInvocation extends BaseToolInvocation<
     } catch (error) {
       const errorMessage =
         error instanceof Error ? error.message : String(error);
-      console.warn(
-        `[MemoryTool] Error executing save_memory for fact "${fact}": ${errorMessage}`,
-      );
       return {
         llmContent: JSON.stringify({
           success: false,
@@ -367,10 +364,6 @@ export class MemoryTool
 
       await fsAdapter.writeFile(memoryFilePath, newContent, 'utf-8');
     } catch (error) {
-      console.error(
-        `[MemoryTool] Error adding memory entry to ${memoryFilePath}:`,
-        error,
-      );
       throw new Error(
         `[MemoryTool] Failed to add memory entry: ${error instanceof Error ? error.message : String(error)}`,
       );

packages/core/src/tools/smart-edit.test.ts

@@ -729,7 +729,7 @@ describe('SmartEditTool', () => {
             result.returnDisplay.diffStat?.model_removed_lines,
           );
         } else if (result.error) {
-          console.error(`Edit failed for ${file.path}:`, result.error);
+          throw result.error;
         }
       }
 

packages/core/src/tools/tool-registry.ts

@@ -416,7 +416,7 @@ export class ToolRegistry {
         );
       }
     } catch (e) {
-      console.error(`Tool discovery command "${discoveryCmd}" failed:`, e);
+      debugLogger.error(`Tool discovery command "${discoveryCmd}" failed:`, e);
       throw e;
     }
   }

packages/core/src/tools/web-search.ts

@@ -14,6 +14,7 @@ import { ToolErrorType } from './tool-error.js';
 import { getErrorMessage } from '../utils/errors.js';
 import { type Config } from '../config/config.js';
 import { getResponseText } from '../utils/partUtils.js';
+import { debugLogger } from '../utils/debugLogger.js';
 
 interface GroundingChunkWeb {
   uri?: string;
@@ -167,7 +168,7 @@ class WebSearchToolInvocation extends BaseToolInvocation<
       const errorMessage = `Error during web search for query "${
         this.params.query
       }": ${getErrorMessage(error)}`;
-      console.error(errorMessage, error);
+      debugLogger.warn(errorMessage, error);
       return {
         llmContent: `Error: ${errorMessage}`,
         returnDisplay: `Error performing web search.`,

packages/core/src/tools/write-file.ts

@@ -44,6 +44,7 @@ import { FileOperation } from '../telemetry/metrics.js';
 import { getSpecificMimeType } from '../utils/fileUtils.js';
 import { getLanguageFromFilePath } from '../utils/language-detection.js';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
+import { debugLogger } from '../utils/debugLogger.js';
 
 /**
  * Parameters for the WriteFile tool
@@ -377,7 +378,7 @@ class WriteFileToolInvocation extends BaseToolInvocation<
 
         // Include stack trace in debug mode for better troubleshooting
         if (this.config.getDebugMode() && error.stack) {
-          console.error('Write file error stack:', error.stack);
+          debugLogger.error('Write file error stack:', error.stack);
         }
       } else if (error instanceof Error) {
         errorMsg = `Error writing to file: ${error.message}`;

packages/core/src/utils/debugLogger.ts

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/* eslint-disable no-console */
 import * as fs from 'node:fs';
 import * as util from 'node:util';
 

packages/core/src/utils/editCorrector.ts

@@ -22,6 +22,7 @@ import {
 } from '../utils/messageInspectors.js';
 import * as fs from 'node:fs';
 import { promptIdContext } from './promptIdContext.js';
+import { debugLogger } from './debugLogger.js';
 
 const CODE_CORRECTION_SYSTEM_PROMPT = `
 You are an expert code-editing assistant. Your task is to analyze a failed edit attempt and provide a corrected version of the text snippets.
@@ -434,7 +435,7 @@ Return ONLY the corrected target snippet in the specified JSON format with the k
       throw error;
     }
 
-    console.error(
+    debugLogger.warn(
       'Error during LLM call for old string snippet correction:',
       error,
     );
@@ -523,7 +524,7 @@ Return ONLY the corrected string in the specified JSON format with the key 'corr
       throw error;
     }
 
-    console.error('Error during LLM call for new_string correction:', error);
+    debugLogger.warn('Error during LLM call for new_string correction:', error);
     return originalNewString;
   }
 }
@@ -593,7 +594,7 @@ Return ONLY the corrected string in the specified JSON format with the key 'corr
       throw error;
     }
 
-    console.error(
+    debugLogger.warn(
       'Error during LLM call for new_string escaping correction:',
       error,
     );
@@ -660,7 +661,7 @@ Return ONLY the corrected string in the specified JSON format with the key 'corr
       throw error;
     }
 
-    console.error(
+    debugLogger.warn(
       'Error during LLM call for string escaping correction:',
       error,
     );

packages/core/src/utils/errorReporting.test.ts

@@ -9,12 +9,13 @@ import fs from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
 import { reportError } from './errorReporting.js';
+import { debugLogger } from './debugLogger.js';
 
 // Use a type alias for SpyInstance as it's not directly exported
 type SpyInstance = ReturnType<typeof vi.spyOn>;
 
 describe('reportError', () => {
-  let consoleErrorSpy: SpyInstance;
+  let debugLoggerErrorSpy: SpyInstance;
   let testDir: string;
   const MOCK_TIMESTAMP = '2025-01-01T00-00-00-000Z';
 
@@ -22,7 +23,9 @@ describe('reportError', () => {
     // Create a temporary directory for logs
     testDir = await fs.mkdtemp(path.join(os.tmpdir(), 'gemini-report-test-'));
     vi.resetAllMocks();
-    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
+    debugLoggerErrorSpy = vi
+      .spyOn(debugLogger, 'error')
+      .mockImplementation(() => {});
     vi.spyOn(Date.prototype, 'toISOString').mockReturnValue(MOCK_TIMESTAMP);
   });
 
@@ -54,9 +57,10 @@ describe('reportError', () => {
       context,
     });
 
-    // Verify the console log
+    // Verify the user feedback
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Full report available at: ${expectedReportPath}`,
+      error,
     );
   });
 
@@ -75,8 +79,9 @@ describe('reportError', () => {
       error: { message: 'Test plain object error' },
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Full report available at: ${expectedReportPath}`,
+      error,
     );
   });
 
@@ -95,8 +100,9 @@ describe('reportError', () => {
       error: { message: 'Just a string error' },
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Full report available at: ${expectedReportPath}`,
+      error,
     );
   });
 
@@ -109,15 +115,18 @@ describe('reportError', () => {
 
     await reportError(error, baseMessage, context, type, nonExistentDir);
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Additionally, failed to write detailed error report:`,
       expect.any(Error), // The actual write error
     );
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       'Original error that triggered report generation:',
       error,
     );
-    expect(consoleErrorSpy).toHaveBeenCalledWith('Original context:', context);
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
+      'Original context:',
+      context,
+    );
   });
 
   it('should handle stringification failure of report content (e.g. BigInt in context)', async () => {
@@ -146,15 +155,15 @@ describe('reportError', () => {
 
     await reportError(error, baseMessage, context, type, testDir);
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Could not stringify report content (likely due to context):`,
       stringifyError,
     );
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       'Original error that triggered report generation:',
       error,
     );
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       'Original context could not be stringified or included in report.',
     );
 
@@ -165,8 +174,9 @@ describe('reportError', () => {
       error: { message: error.message, stack: error.stack },
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Partial report (excluding context) available at: ${expectedMinimalReportPath}`,
+      error,
     );
   });
 
@@ -186,8 +196,9 @@ describe('reportError', () => {
       error: { message: 'Error without context', stack: 'No context stack' },
     });
 
-    expect(consoleErrorSpy).toHaveBeenCalledWith(
+    expect(debugLoggerErrorSpy).toHaveBeenCalledWith(
       `${baseMessage} Full report available at: ${expectedReportPath}`,
+      error,
     );
   });
 });

packages/core/src/utils/errorReporting.ts

@@ -8,6 +8,7 @@ import fs from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
 import type { Content } from '@google/genai';
+import { debugLogger } from './debugLogger.js';
 
 interface ErrorReportData {
   error: { message: string; stack?: string } | { message: string };
@@ -16,7 +17,7 @@ interface ErrorReportData {
 }
 
 /**
- * Generates an error report, writes it to a temporary file, and logs information to console.error.
+ * Generates an error report, writes it to a temporary file, and logs information to user
  * @param error The error object.
  * @param context The relevant context (e.g., chat history, request contents).
  * @param type A string to identify the type of error (e.g., 'startChat', 'generateJson-api').
@@ -59,13 +60,16 @@ export async function reportError(
     stringifiedReportContent = JSON.stringify(reportContent, null, 2);
   } catch (stringifyError) {
     // This can happen if context contains something like BigInt
-    console.error(
+    debugLogger.error(
       `${baseMessage} Could not stringify report content (likely due to context):`,
       stringifyError,
     );
-    console.error('Original error that triggered report generation:', error);
+    debugLogger.error(
+      'Original error that triggered report generation:',
+      error,
+    );
     if (context) {
-      console.error(
+      debugLogger.error(
         'Original context could not be stringified or included in report.',
       );
     }
@@ -75,11 +79,12 @@ export async function reportError(
       stringifiedReportContent = JSON.stringify(minimalReportContent, null, 2);
       // Still try to write the minimal report
       await fs.writeFile(reportPath, stringifiedReportContent);
-      console.error(
+      debugLogger.error(
         `${baseMessage} Partial report (excluding context) available at: ${reportPath}`,
+        error,
       );
     } catch (minimalWriteError) {
-      console.error(
+      debugLogger.error(
         `${baseMessage} Failed to write even a minimal error report:`,
         minimalWriteError,
       );
@@ -89,28 +94,37 @@ export async function reportError(
 
   try {
     await fs.writeFile(reportPath, stringifiedReportContent);
-    console.error(`${baseMessage} Full report available at: ${reportPath}`);
+    debugLogger.error(
+      `${baseMessage} Full report available at: ${reportPath}`,
+      error,
+    );
   } catch (writeError) {
-    console.error(
+    debugLogger.error(
       `${baseMessage} Additionally, failed to write detailed error report:`,
       writeError,
     );
     // Log the original error as a fallback if report writing fails
-    console.error('Original error that triggered report generation:', error);
+    debugLogger.error(
+      'Original error that triggered report generation:',
+      error,
+    );
+
     if (context) {
       // Context was stringifiable, but writing the file failed.
       // We already have stringifiedReportContent, but it might be too large for console.
       // So, we try to log the original context object, and if that fails, its stringified version (truncated).
       try {
-        console.error('Original context:', context);
+        debugLogger.error('Original context:', context);
       } catch {
         try {
-          console.error(
+          debugLogger.error(
             'Original context (stringified, truncated):',
             JSON.stringify(context).substring(0, 1000),
           );
         } catch {
-          console.error('Original context could not be logged or stringified.');
+          debugLogger.error(
+            'Original context could not be logged or stringified.',
+          );
         }
       }
     }

packages/core/src/utils/getFolderStructure.ts

@@ -342,7 +342,10 @@ export async function getFolderStructure(
 
     return `${summary}\n\n${resolvedPath}${path.sep}\n${structureLines.join('\n')}`;
   } catch (error: unknown) {
-    console.error(`Error getting folder structure for ${resolvedPath}:`, error);
+    debugLogger.warn(
+      `Error getting folder structure for ${resolvedPath}:`,
+      error,
+    );
     return `Error processing directory "${resolvedPath}": ${getErrorMessage(error)}`;
   }
 }

packages/core/src/utils/memoryDiscovery.ts

@@ -31,7 +31,7 @@ const logger = {
     debugLogger.warn('[WARN] [MemoryDiscovery]', ...args),
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   error: (...args: any[]) =>
-    console.error('[ERROR] [MemoryDiscovery]', ...args),
+    debugLogger.error('[ERROR] [MemoryDiscovery]', ...args),
 };
 
 export interface GeminiFileContent {

packages/core/src/utils/retry.ts

@@ -232,7 +232,7 @@ export async function retryWithBackoff<T>(
                 continue;
               }
             } catch (fallbackError) {
-              console.warn('Model fallback failed:', fallbackError);
+              debugLogger.warn('Model fallback failed:', fallbackError);
             }
           }
           throw classifiedError instanceof RetryableQuotaError
@@ -241,7 +241,7 @@ export async function retryWithBackoff<T>(
         }
 
         if (classifiedError instanceof RetryableQuotaError) {
-          console.warn(
+          debugLogger.warn(
             `Attempt ${attempt} failed: ${classifiedError.message}. Retrying after ${classifiedError.retryDelayMs}ms...`,
           );
           await delay(classifiedError.retryDelayMs, signal);
@@ -300,7 +300,7 @@ function logRetryAttempt(
   if (errorStatus === 429) {
     debugLogger.warn(message, error);
   } else if (errorStatus && errorStatus >= 500 && errorStatus < 600) {
-    console.error(message, error);
+    debugLogger.warn(message, error);
   } else if (error instanceof Error) {
     // Fallback for errors that might not have a status but have a message
     if (error.message.includes('429')) {
@@ -309,7 +309,7 @@ function logRetryAttempt(
         error,
       );
     } else if (error.message.match(/5\d{2}/)) {
-      console.error(
+      debugLogger.warn(
         `Attempt ${attempt} failed with 5xx error. Retrying with backoff...`,
         error,
       );

packages/core/src/utils/summarizer.test.ts

@@ -19,6 +19,7 @@ import type {
   ResolvedModelConfig,
 } from '../services/modelConfigService.js';
 import { DEFAULT_GEMINI_MODEL } from '../config/models.js';
+import { debugLogger } from './debugLogger.js';
 
 // Mock GeminiClient and Config constructor
 vi.mock('../core/client.js');
@@ -58,11 +59,11 @@ describe('summarizers', () => {
     (mockGeminiClient.generateContent as Mock) = vi.fn();
 
     vi.spyOn(console, 'error').mockImplementation(() => {});
+    vi.spyOn(debugLogger, 'warn').mockImplementation(() => {});
   });
 
   afterEach(() => {
-    vi.clearAllMocks();
+    vi.restoreAllMocks();
-    (console.error as Mock).mockRestore();
   });
 
   describe('summarizeToolOutput', () => {