Refac: Centralize storage file management (#4078)

Co-authored-by: Taylor Mullen <[email protected]>

9 files changed, 336 insertions, 277 deletions

diff --git a/packages/core/src/utils/editCorrector.test.ts b/packages/core/src/utils/editCorrector.test.ts
index cd588312..a7ef9522 100644
--- a/packages/core/src/utils/editCorrector.test.ts
+++ b/packages/core/src/utils/editCorrector.test.ts
@@ -27,6 +27,7 @@ let mockSendMessageStream: any;
 
 vi.mock('fs', () => ({
   statSync: vi.fn(),
+  mkdirSync: vi.fn(),
 }));
 
 vi.mock('../core/client.js', () => ({
diff --git a/packages/core/src/utils/installationManager.test.ts b/packages/core/src/utils/installationManager.test.ts
new file mode 100644
index 00000000..d6a35f68
--- /dev/null
+++ b/packages/core/src/utils/installationManager.test.ts
@@ -0,0 +1,102 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi, describe, it, expect, beforeEach, afterEach, Mock } from 'vitest';
+import { InstallationManager } from './installationManager.js';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import path from 'node:path';
+import { randomUUID } from 'crypto';
+
+vi.mock('node:fs', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('node:fs')>();
+  return {
+    ...actual,
+    readFileSync: vi.fn(actual.readFileSync),
+    existsSync: vi.fn(actual.existsSync),
+  } as typeof actual;
+});
+
+vi.mock('os', async (importOriginal) => {
+  const os = await importOriginal<typeof import('os')>();
+  return {
+    ...os,
+    homedir: vi.fn(),
+  };
+});
+
+vi.mock('crypto', async (importOriginal) => {
+  const crypto = await importOriginal<typeof import('crypto')>();
+  return {
+    ...crypto,
+    randomUUID: vi.fn(),
+  };
+});
+
+describe('InstallationManager', () => {
+  let tempHomeDir: string;
+  let installationManager: InstallationManager;
+  const installationIdFile = () =>
+    path.join(tempHomeDir, '.gemini', 'installation_id');
+
+  beforeEach(() => {
+    tempHomeDir = fs.mkdtempSync(
+      path.join(os.tmpdir(), 'gemini-cli-test-home-'),
+    );
+    (os.homedir as Mock).mockReturnValue(tempHomeDir);
+    installationManager = new InstallationManager();
+  });
+
+  afterEach(() => {
+    fs.rmSync(tempHomeDir, { recursive: true, force: true });
+    vi.clearAllMocks();
+  });
+
+  describe('getInstallationId', () => {
+    it('should create and write a new installation ID if one does not exist', () => {
+      const newId = 'new-uuid-123';
+      (randomUUID as Mock).mockReturnValue(newId);
+
+      const installationId = installationManager.getInstallationId();
+
+      expect(installationId).toBe(newId);
+      expect(fs.existsSync(installationIdFile())).toBe(true);
+      expect(fs.readFileSync(installationIdFile(), 'utf-8')).toBe(newId);
+    });
+
+    it('should read an existing installation ID from a file', () => {
+      const existingId = 'existing-uuid-123';
+      fs.mkdirSync(path.dirname(installationIdFile()), { recursive: true });
+      fs.writeFileSync(installationIdFile(), existingId);
+
+      const installationId = installationManager.getInstallationId();
+
+      expect(installationId).toBe(existingId);
+    });
+
+    it('should return the same ID on subsequent calls', () => {
+      const firstId = installationManager.getInstallationId();
+      const secondId = installationManager.getInstallationId();
+      expect(secondId).toBe(firstId);
+    });
+
+    it('should handle read errors and return a fallback ID', () => {
+      vi.mocked(fs.existsSync).mockReturnValueOnce(true);
+      const readSpy = vi.mocked(fs.readFileSync);
+      readSpy.mockImplementationOnce(() => {
+        throw new Error('Read error');
+      });
+      const consoleErrorSpy = vi
+        .spyOn(console, 'error')
+        .mockImplementation(() => {});
+
+      const id = installationManager.getInstallationId();
+
+      expect(id).toBe('123456789');
+      expect(consoleErrorSpy).toHaveBeenCalled();
+    });
+  });
+});
diff --git a/packages/core/src/utils/installationManager.ts b/packages/core/src/utils/installationManager.ts
new file mode 100644
index 00000000..9146ddd0
--- /dev/null
+++ b/packages/core/src/utils/installationManager.ts
@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'fs';
+import { randomUUID } from 'crypto';
+import * as path from 'node:path';
+import { Storage } from '../config/storage.js';
+
+export class InstallationManager {
+  private getInstallationIdPath(): string {
+    return Storage.getInstallationIdPath();
+  }
+
+  private readInstallationIdFromFile(): string | null {
+    const installationIdFile = this.getInstallationIdPath();
+    if (fs.existsSync(installationIdFile)) {
+      const installationid = fs
+        .readFileSync(installationIdFile, 'utf-8')
+        .trim();
+      return installationid || null;
+    }
+    return null;
+  }
+
+  private writeInstallationIdToFile(installationId: string) {
+    const installationIdFile = this.getInstallationIdPath();
+    const dir = path.dirname(installationIdFile);
+    fs.mkdirSync(dir, { recursive: true });
+    fs.writeFileSync(installationIdFile, installationId, 'utf-8');
+  }
+
+  /**
+   * Retrieves the installation ID from a file, creating it if it doesn't exist.
+   * This ID is used for unique user installation tracking.
+   * @returns A UUID string for the user.
+   */
+  getInstallationId(): string {
+    try {
+      let installationId = this.readInstallationIdFromFile();
+
+      if (!installationId) {
+        installationId = randomUUID();
+        this.writeInstallationIdToFile(installationId);
+      }
+
+      return installationId;
+    } catch (error) {
+      console.error(
+        'Error accessing installation ID file, generating ephemeral ID:',
+        error,
+      );
+      return '123456789';
+    }
+  }
+}
diff --git a/packages/core/src/utils/paths.ts b/packages/core/src/utils/paths.ts
index e7cf54cc..fe690b39 100644
--- a/packages/core/src/utils/paths.ts
+++ b/packages/core/src/utils/paths.ts
@@ -10,8 +10,6 @@ import * as crypto from 'crypto';
 
 export const GEMINI_DIR = '.gemini';
 export const GOOGLE_ACCOUNTS_FILENAME = 'google_accounts.json';
-const TMP_DIR_NAME = 'tmp';
-const COMMANDS_DIR_NAME = 'commands';
 
 /**
  * Special characters that need to be escaped in file paths for shell compatibility.
@@ -175,33 +173,6 @@ export function getProjectHash(projectRoot: string): string {
 }
 
 /**
- * Generates a unique temporary directory path for a project.
- * @param projectRoot The absolute path to the project's root directory.
- * @returns The path to the project's temporary directory.
- */
-export function getProjectTempDir(projectRoot: string): string {
-  const hash = getProjectHash(projectRoot);
-  return path.join(os.homedir(), GEMINI_DIR, TMP_DIR_NAME, hash);
-}
-
-/**
- * Returns the absolute path to the user-level commands directory.
- * @returns The path to the user's commands directory.
- */
-export function getUserCommandsDir(): string {
-  return path.join(os.homedir(), GEMINI_DIR, COMMANDS_DIR_NAME);
-}
-
-/**
- * Returns the absolute path to the project-level commands directory.
- * @param projectRoot The absolute path to the project's root directory.
- * @returns The path to the project's commands directory.
- */
-export function getProjectCommandsDir(projectRoot: string): string {
-  return path.join(projectRoot, GEMINI_DIR, COMMANDS_DIR_NAME);
-}
-
-/**
  * Checks if a path is a subpath of another path.
  * @param parentPath The parent path.
  * @param childPath The child path.
diff --git a/packages/core/src/utils/user_account.test.ts b/packages/core/src/utils/userAccountManager.test.ts
index 35231ca3..1e7e05aa 100644
--- a/packages/core/src/utils/user_account.test.ts
+++ b/packages/core/src/utils/userAccountManager.test.ts
@@ -5,12 +5,7 @@
  */
 
 import { vi, describe, it, expect, beforeEach, afterEach, Mock } from 'vitest';
-import {
-  cacheGoogleAccount,
-  getCachedGoogleAccount,
-  clearCachedGoogleAccount,
-  getLifetimeGoogleAccounts,
-} from './user_account.js';
+import { UserAccountManager } from './userAccountManager.js';
 import * as fs from 'node:fs';
 import * as os from 'node:os';
 import path from 'node:path';
@@ -23,16 +18,21 @@ vi.mock('os', async (importOriginal) => {
   };
 });
 
-describe('user_account', () => {
+describe('UserAccountManager', () => {
   let tempHomeDir: string;
-  const accountsFile = () =>
-    path.join(tempHomeDir, '.gemini', 'google_accounts.json');
+  let userAccountManager: UserAccountManager;
+  let accountsFile: () => string;
+
   beforeEach(() => {
     tempHomeDir = fs.mkdtempSync(
       path.join(os.tmpdir(), 'gemini-cli-test-home-'),
     );
     (os.homedir as Mock).mockReturnValue(tempHomeDir);
+    accountsFile = () =>
+      path.join(tempHomeDir, '.gemini', 'google_accounts.json');
+    userAccountManager = new UserAccountManager();
   });
+
   afterEach(() => {
     fs.rmSync(tempHomeDir, { recursive: true, force: true });
     vi.clearAllMocks();
@@ -40,7 +40,7 @@ describe('user_account', () => {
 
   describe('cacheGoogleAccount', () => {
     it('should create directory and write initial account file', async () => {
-      await cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
 
       // Verify Google Account ID was cached
       expect(fs.existsSync(accountsFile())).toBe(true);
@@ -60,7 +60,7 @@ describe('user_account', () => {
         ),
       );
 
-      await cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
 
       expect(fs.readFileSync(accountsFile(), 'utf-8')).toBe(
         JSON.stringify(
@@ -84,8 +84,8 @@ describe('user_account', () => {
           2,
         ),
       );
-      await cacheGoogleAccount('[email protected]');
-      await cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
 
       expect(fs.readFileSync(accountsFile(), 'utf-8')).toBe(
         JSON.stringify(
@@ -103,7 +103,7 @@ describe('user_account', () => {
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      await cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
 
       expect(consoleLogSpy).toHaveBeenCalled();
       expect(JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'))).toEqual({
@@ -122,7 +122,7 @@ describe('user_account', () => {
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      await cacheGoogleAccount('[email protected]');
+      await userAccountManager.cacheGoogleAccount('[email protected]');
 
       expect(consoleLogSpy).toHaveBeenCalled();
       expect(JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'))).toEqual({
@@ -139,19 +139,19 @@ describe('user_account', () => {
         accountsFile(),
         JSON.stringify({ active: '[email protected]', old: [] }, null, 2),
       );
-      const account = getCachedGoogleAccount();
+      const account = userAccountManager.getCachedGoogleAccount();
       expect(account).toBe('[email protected]');
     });
 
     it('should return null if file does not exist', () => {
-      const account = getCachedGoogleAccount();
+      const account = userAccountManager.getCachedGoogleAccount();
       expect(account).toBeNull();
     });
 
     it('should return null if file is empty', () => {
       fs.mkdirSync(path.dirname(accountsFile()), { recursive: true });
       fs.writeFileSync(accountsFile(), '');
-      const account = getCachedGoogleAccount();
+      const account = userAccountManager.getCachedGoogleAccount();
       expect(account).toBeNull();
     });
 
@@ -162,7 +162,7 @@ describe('user_account', () => {
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      const account = getCachedGoogleAccount();
+      const account = userAccountManager.getCachedGoogleAccount();
 
       expect(account).toBeNull();
       expect(consoleLogSpy).toHaveBeenCalled();
@@ -171,7 +171,7 @@ describe('user_account', () => {
     it('should return null if active key is missing', () => {
       fs.mkdirSync(path.dirname(accountsFile()), { recursive: true });
       fs.writeFileSync(accountsFile(), JSON.stringify({ old: [] }));
-      const account = getCachedGoogleAccount();
+      const account = userAccountManager.getCachedGoogleAccount();
       expect(account).toBeNull();
     });
   });
@@ -188,7 +188,7 @@ describe('user_account', () => {
         ),
       );
 
-      await clearCachedGoogleAccount();
+      await userAccountManager.clearCachedGoogleAccount();
 
       const stored = JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'));
       expect(stored.active).toBeNull();
@@ -198,7 +198,7 @@ describe('user_account', () => {
     it('should handle empty file gracefully', async () => {
       fs.mkdirSync(path.dirname(accountsFile()), { recursive: true });
       fs.writeFileSync(accountsFile(), '');
-      await clearCachedGoogleAccount();
+      await userAccountManager.clearCachedGoogleAccount();
       const stored = JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'));
       expect(stored.active).toBeNull();
       expect(stored.old).toEqual([]);
@@ -211,7 +211,7 @@ describe('user_account', () => {
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      await clearCachedGoogleAccount();
+      await userAccountManager.clearCachedGoogleAccount();
 
       expect(consoleLogSpy).toHaveBeenCalled();
       const stored = JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'));
@@ -226,7 +226,7 @@ describe('user_account', () => {
         JSON.stringify({ active: null, old: ['[email protected]'] }, null, 2),
       );
 
-      await clearCachedGoogleAccount();
+      await userAccountManager.clearCachedGoogleAccount();
 
       const stored = JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'));
       expect(stored.active).toBeNull();
@@ -247,7 +247,7 @@ describe('user_account', () => {
         ),
       );
 
-      await clearCachedGoogleAccount();
+      await userAccountManager.clearCachedGoogleAccount();
 
       const stored = JSON.parse(fs.readFileSync(accountsFile(), 'utf-8'));
       expect(stored.active).toBeNull();
@@ -257,24 +257,24 @@ describe('user_account', () => {
 
   describe('getLifetimeGoogleAccounts', () => {
     it('should return 0 if the file does not exist', () => {
-      expect(getLifetimeGoogleAccounts()).toBe(0);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(0);
     });
 
     it('should return 0 if the file is empty', () => {
       fs.mkdirSync(path.dirname(accountsFile()), { recursive: true });
       fs.writeFileSync(accountsFile(), '');
-      expect(getLifetimeGoogleAccounts()).toBe(0);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(0);
     });
 
     it('should return 0 if the file is corrupted', () => {
       fs.mkdirSync(path.dirname(accountsFile()), { recursive: true });
       fs.writeFileSync(accountsFile(), 'invalid json');
-      const consoleLogSpy = vi
+      const consoleDebugSpy = vi
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      expect(getLifetimeGoogleAccounts()).toBe(0);
-      expect(consoleLogSpy).toHaveBeenCalled();
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(0);
+      expect(consoleDebugSpy).toHaveBeenCalled();
     });
 
     it('should return 1 if there is only an active account', () => {
@@ -283,7 +283,7 @@ describe('user_account', () => {
         accountsFile(),
         JSON.stringify({ active: '[email protected]', old: [] }),
       );
-      expect(getLifetimeGoogleAccounts()).toBe(1);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(1);
     });
 
     it('should correctly count old accounts when active is null', () => {
@@ -295,7 +295,7 @@ describe('user_account', () => {
           old: ['[email protected]', '[email protected]'],
         }),
       );
-      expect(getLifetimeGoogleAccounts()).toBe(2);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(2);
     });
 
     it('should correctly count both active and old accounts', () => {
@@ -307,7 +307,7 @@ describe('user_account', () => {
           old: ['[email protected]', '[email protected]'],
         }),
       );
-      expect(getLifetimeGoogleAccounts()).toBe(3);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(3);
     });
 
     it('should handle valid JSON with incorrect schema by returning 0', () => {
@@ -320,7 +320,7 @@ describe('user_account', () => {
         .spyOn(console, 'log')
         .mockImplementation(() => {});
 
-      expect(getLifetimeGoogleAccounts()).toBe(0);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(0);
       expect(consoleLogSpy).toHaveBeenCalled();
     });
 
@@ -333,7 +333,7 @@ describe('user_account', () => {
           old: ['[email protected]', '[email protected]'],
         }),
       );
-      expect(getLifetimeGoogleAccounts()).toBe(2);
+      expect(userAccountManager.getLifetimeGoogleAccounts()).toBe(2);
     });
   });
 });
diff --git a/packages/core/src/utils/userAccountManager.ts b/packages/core/src/utils/userAccountManager.ts
new file mode 100644
index 00000000..28d3cef9
--- /dev/null
+++ b/packages/core/src/utils/userAccountManager.ts
@@ -0,0 +1,140 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import path from 'node:path';
+import { promises as fsp, readFileSync } from 'node:fs';
+import { Storage } from '../config/storage.js';
+
+interface UserAccounts {
+  active: string | null;
+  old: string[];
+}
+
+export class UserAccountManager {
+  private getGoogleAccountsCachePath(): string {
+    return Storage.getGoogleAccountsPath();
+  }
+
+  /**
+   * Parses and validates the string content of an accounts file.
+   * @param content The raw string content from the file.
+   * @returns A valid UserAccounts object.
+   */
+  private parseAndValidateAccounts(content: string): UserAccounts {
+    const defaultState = { active: null, old: [] };
+    if (!content.trim()) {
+      return defaultState;
+    }
+
+    const parsed = JSON.parse(content);
+
+    // Inlined validation logic
+    if (typeof parsed !== 'object' || parsed === null) {
+      console.log('Invalid accounts file schema, starting fresh.');
+      return defaultState;
+    }
+    const { active, old } = parsed as Partial<UserAccounts>;
+    const isValid =
+      (active === undefined || active === null || typeof active === 'string') &&
+      (old === undefined ||
+        (Array.isArray(old) && old.every((i) => typeof i === 'string')));
+
+    if (!isValid) {
+      console.log('Invalid accounts file schema, starting fresh.');
+      return defaultState;
+    }
+
+    return {
+      active: parsed.active ?? null,
+      old: parsed.old ?? [],
+    };
+  }
+
+  private readAccountsSync(filePath: string): UserAccounts {
+    const defaultState = { active: null, old: [] };
+    try {
+      const content = readFileSync(filePath, 'utf-8');
+      return this.parseAndValidateAccounts(content);
+    } catch (error) {
+      if (
+        error instanceof Error &&
+        'code' in error &&
+        error.code === 'ENOENT'
+      ) {
+        return defaultState;
+      }
+      console.log('Error during sync read of accounts, starting fresh.', error);
+      return defaultState;
+    }
+  }
+
+  private async readAccounts(filePath: string): Promise<UserAccounts> {
+    const defaultState = { active: null, old: [] };
+    try {
+      const content = await fsp.readFile(filePath, 'utf-8');
+      return this.parseAndValidateAccounts(content);
+    } catch (error) {
+      if (
+        error instanceof Error &&
+        'code' in error &&
+        error.code === 'ENOENT'
+      ) {
+        return defaultState;
+      }
+      console.log('Could not parse accounts file, starting fresh.', error);
+      return defaultState;
+    }
+  }
+
+  async cacheGoogleAccount(email: string): Promise<void> {
+    const filePath = this.getGoogleAccountsCachePath();
+    await fsp.mkdir(path.dirname(filePath), { recursive: true });
+
+    const accounts = await this.readAccounts(filePath);
+
+    if (accounts.active && accounts.active !== email) {
+      if (!accounts.old.includes(accounts.active)) {
+        accounts.old.push(accounts.active);
+      }
+    }
+
+    // If the new email was in the old list, remove it
+    accounts.old = accounts.old.filter((oldEmail) => oldEmail !== email);
+
+    accounts.active = email;
+    await fsp.writeFile(filePath, JSON.stringify(accounts, null, 2), 'utf-8');
+  }
+
+  getCachedGoogleAccount(): string | null {
+    const filePath = this.getGoogleAccountsCachePath();
+    const accounts = this.readAccountsSync(filePath);
+    return accounts.active;
+  }
+
+  getLifetimeGoogleAccounts(): number {
+    const filePath = this.getGoogleAccountsCachePath();
+    const accounts = this.readAccountsSync(filePath);
+    const allAccounts = new Set(accounts.old);
+    if (accounts.active) {
+      allAccounts.add(accounts.active);
+    }
+    return allAccounts.size;
+  }
+
+  async clearCachedGoogleAccount(): Promise<void> {
+    const filePath = this.getGoogleAccountsCachePath();
+    const accounts = await this.readAccounts(filePath);
+
+    if (accounts.active) {
+      if (!accounts.old.includes(accounts.active)) {
+        accounts.old.push(accounts.active);
+      }
+      accounts.active = null;
+    }
+
+    await fsp.writeFile(filePath, JSON.stringify(accounts, null, 2), 'utf-8');
+  }
+}
diff --git a/packages/core/src/utils/user_account.ts b/packages/core/src/utils/user_account.ts
deleted file mode 100644
index 18b7dcf4..00000000
--- a/packages/core/src/utils/user_account.ts
+++ /dev/null
@@ -1,131 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import path from 'node:path';
-import { promises as fsp, readFileSync } from 'node:fs';
-import * as os from 'os';
-import { GEMINI_DIR, GOOGLE_ACCOUNTS_FILENAME } from './paths.js';
-
-interface UserAccounts {
-  active: string | null;
-  old: string[];
-}
-
-function getGoogleAccountsCachePath(): string {
-  return path.join(os.homedir(), GEMINI_DIR, GOOGLE_ACCOUNTS_FILENAME);
-}
-
-/**
- * Parses and validates the string content of an accounts file.
- * @param content The raw string content from the file.
- * @returns A valid UserAccounts object.
- */
-function parseAndValidateAccounts(content: string): UserAccounts {
-  const defaultState = { active: null, old: [] };
-  if (!content.trim()) {
-    return defaultState;
-  }
-
-  const parsed = JSON.parse(content);
-
-  // Inlined validation logic
-  if (typeof parsed !== 'object' || parsed === null) {
-    console.log('Invalid accounts file schema, starting fresh.');
-    return defaultState;
-  }
-  const { active, old } = parsed as Partial<UserAccounts>;
-  const isValid =
-    (active === undefined || active === null || typeof active === 'string') &&
-    (old === undefined ||
-      (Array.isArray(old) && old.every((i) => typeof i === 'string')));
-
-  if (!isValid) {
-    console.log('Invalid accounts file schema, starting fresh.');
-    return defaultState;
-  }
-
-  return {
-    active: parsed.active ?? null,
-    old: parsed.old ?? [],
-  };
-}
-
-function readAccountsSync(filePath: string): UserAccounts {
-  const defaultState = { active: null, old: [] };
-  try {
-    const content = readFileSync(filePath, 'utf-8');
-    return parseAndValidateAccounts(content);
-  } catch (error) {
-    if (error instanceof Error && 'code' in error && error.code === 'ENOENT') {
-      return defaultState;
-    }
-    console.log('Error during sync read of accounts, starting fresh.', error);
-    return defaultState;
-  }
-}
-
-async function readAccounts(filePath: string): Promise<UserAccounts> {
-  const defaultState = { active: null, old: [] };
-  try {
-    const content = await fsp.readFile(filePath, 'utf-8');
-    return parseAndValidateAccounts(content);
-  } catch (error) {
-    if (error instanceof Error && 'code' in error && error.code === 'ENOENT') {
-      return defaultState;
-    }
-    console.log('Could not parse accounts file, starting fresh.', error);
-    return defaultState;
-  }
-}
-
-export async function cacheGoogleAccount(email: string): Promise<void> {
-  const filePath = getGoogleAccountsCachePath();
-  await fsp.mkdir(path.dirname(filePath), { recursive: true });
-
-  const accounts = await readAccounts(filePath);
-
-  if (accounts.active && accounts.active !== email) {
-    if (!accounts.old.includes(accounts.active)) {
-      accounts.old.push(accounts.active);
-    }
-  }
-
-  // If the new email was in the old list, remove it
-  accounts.old = accounts.old.filter((oldEmail) => oldEmail !== email);
-
-  accounts.active = email;
-  await fsp.writeFile(filePath, JSON.stringify(accounts, null, 2), 'utf-8');
-}
-
-export function getCachedGoogleAccount(): string | null {
-  const filePath = getGoogleAccountsCachePath();
-  const accounts = readAccountsSync(filePath);
-  return accounts.active;
-}
-
-export function getLifetimeGoogleAccounts(): number {
-  const filePath = getGoogleAccountsCachePath();
-  const accounts = readAccountsSync(filePath);
-  const allAccounts = new Set(accounts.old);
-  if (accounts.active) {
-    allAccounts.add(accounts.active);
-  }
-  return allAccounts.size;
-}
-
-export async function clearCachedGoogleAccount(): Promise<void> {
-  const filePath = getGoogleAccountsCachePath();
-  const accounts = await readAccounts(filePath);
-
-  if (accounts.active) {
-    if (!accounts.old.includes(accounts.active)) {
-      accounts.old.push(accounts.active);
-    }
-    accounts.active = null;
-  }
-
-  await fsp.writeFile(filePath, JSON.stringify(accounts, null, 2), 'utf-8');
-}
diff --git a/packages/core/src/utils/user_id.test.ts b/packages/core/src/utils/user_id.test.ts
deleted file mode 100644
index 5c11d773..00000000
--- a/packages/core/src/utils/user_id.test.ts
+++ /dev/null
@@ -1,24 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import { describe, it, expect } from 'vitest';
-import { getInstallationId } from './user_id.js';
-
-describe('user_id', () => {
-  describe('getInstallationId', () => {
-    it('should return a valid UUID format string', () => {
-      const installationId = getInstallationId();
-
-      expect(installationId).toBeDefined();
-      expect(typeof installationId).toBe('string');
-      expect(installationId.length).toBeGreaterThan(0);
-
-      // Should return the same ID on subsequent calls (consistent)
-      const secondCall = getInstallationId();
-      expect(secondCall).toBe(installationId);
-    });
-  });
-});
diff --git a/packages/core/src/utils/user_id.ts b/packages/core/src/utils/user_id.ts
deleted file mode 100644
index 6f16806f..00000000
--- a/packages/core/src/utils/user_id.ts
+++ /dev/null
@@ -1,58 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-import * as os from 'os';
-import * as fs from 'fs';
-import * as path from 'path';
-import { randomUUID } from 'crypto';
-import { GEMINI_DIR } from './paths.js';
-
-const homeDir = os.homedir() ?? '';
-const geminiDir = path.join(homeDir, GEMINI_DIR);
-const installationIdFile = path.join(geminiDir, 'installation_id');
-
-function ensureGeminiDirExists() {
-  if (!fs.existsSync(geminiDir)) {
-    fs.mkdirSync(geminiDir, { recursive: true });
-  }
-}
-
-function readInstallationIdFromFile(): string | null {
-  if (fs.existsSync(installationIdFile)) {
-    const installationid = fs.readFileSync(installationIdFile, 'utf-8').trim();
-    return installationid || null;
-  }
-  return null;
-}
-
-function writeInstallationIdToFile(installationId: string) {
-  fs.writeFileSync(installationIdFile, installationId, 'utf-8');
-}
-
-/**
- * Retrieves the installation ID from a file, creating it if it doesn't exist.
- * This ID is used for unique user installation tracking.
- * @returns A UUID string for the user.
- */
-export function getInstallationId(): string {
-  try {
-    ensureGeminiDirExists();
-    let installationId = readInstallationIdFromFile();
-
-    if (!installationId) {
-      installationId = randomUUID();
-      writeInstallationIdToFile(installationId);
-    }
-
-    return installationId;
-  } catch (error) {
-    console.error(
-      'Error accessing installation ID file, generating ephemeral ID:',
-      error,
-    );
-    return '123456789';
-  }
-}