feat(cli): implement /upgrade command (google-gemini#21511)

Author: sehoon38

docs/reference/commands.md

@@ -439,6 +439,12 @@ Slash commands provide meta-level control over the CLI itself.
   - **`nodesc`** or **`nodescriptions`**:
     - **Description:** Hide tool descriptions, showing only the tool names.
 
+### `/upgrade`
+
+- **Description:** Open the Gemini Code Assist upgrade page in your browser.
+  This lets you upgrade your tier for higher usage limits.
+- **Note:** This command is only available when logged in with Google.
+
 ### `/vim`
 
 - **Description:** Toggle vim mode on or off. When vim mode is enabled, the

packages/cli/src/services/BuiltinCommandLoader.test.ts

@@ -142,6 +142,14 @@ vi.mock('../ui/commands/mcpCommand.js', () => ({
   },
 }));
 
+vi.mock('../ui/commands/upgradeCommand.js', () => ({
+  upgradeCommand: {
+    name: 'upgrade',
+    description: 'Upgrade command',
+    kind: 'BUILT_IN',
+  },
+}));
+
 describe('BuiltinCommandLoader', () => {
   let mockConfig: Config;
 
@@ -163,6 +171,9 @@ describe('BuiltinCommandLoader', () => {
         getAllSkills: vi.fn().mockReturnValue([]),
         isAdminEnabled: vi.fn().mockReturnValue(true),
       }),
+      getContentGeneratorConfig: vi.fn().mockReturnValue({
+        authType: 'other',
+      }),
     } as unknown as Config;
 
     restoreCommandMock.mockReturnValue({
@@ -172,6 +183,27 @@ describe('BuiltinCommandLoader', () => {
     });
   });
 
+  it('should include upgrade command when authType is login_with_google', async () => {
+    const { AuthType } = await import('@google/gemini-cli-core');
+    (mockConfig.getContentGeneratorConfig as Mock).mockReturnValue({
+      authType: AuthType.LOGIN_WITH_GOOGLE,
+    });
+    const loader = new BuiltinCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+    const upgradeCmd = commands.find((c) => c.name === 'upgrade');
+    expect(upgradeCmd).toBeDefined();
+  });
+
+  it('should exclude upgrade command when authType is NOT login_with_google', async () => {
+    (mockConfig.getContentGeneratorConfig as Mock).mockReturnValue({
+      authType: 'other',
+    });
+    const loader = new BuiltinCommandLoader(mockConfig);
+    const commands = await loader.loadCommands(new AbortController().signal);
+    const upgradeCmd = commands.find((c) => c.name === 'upgrade');
+    expect(upgradeCmd).toBeUndefined();
+  });
+
   it('should correctly pass the config object to restore command factory', async () => {
     const loader = new BuiltinCommandLoader(mockConfig);
     await loader.loadCommands(new AbortController().signal);
@@ -364,6 +396,9 @@ describe('BuiltinCommandLoader profile', () => {
         getAllSkills: vi.fn().mockReturnValue([]),
         isAdminEnabled: vi.fn().mockReturnValue(true),
       }),
+      getContentGeneratorConfig: vi.fn().mockReturnValue({
+        authType: 'other',
+      }),
     } as unknown as Config;
   });
 

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -16,6 +16,7 @@ import {
   isNightly,
   startupProfiler,
   getAdminErrorMessage,
+  AuthType,
 } from '@google/gemini-cli-core';
 import { aboutCommand } from '../ui/commands/aboutCommand.js';
 import { agentsCommand } from '../ui/commands/agentsCommand.js';
@@ -59,6 +60,7 @@ import { shellsCommand } from '../ui/commands/shellsCommand.js';
 import { vimCommand } from '../ui/commands/vimCommand.js';
 import { setupGithubCommand } from '../ui/commands/setupGithubCommand.js';
 import { terminalSetupCommand } from '../ui/commands/terminalSetupCommand.js';
+import { upgradeCommand } from '../ui/commands/upgradeCommand.js';
 
 /**
  * Loads the core, hard-coded slash commands that are an integral part
@@ -223,6 +225,10 @@ export class BuiltinCommandLoader implements ICommandLoader {
       vimCommand,
       setupGithubCommand,
       terminalSetupCommand,
+      ...(this.config?.getContentGeneratorConfig()?.authType ===
+      AuthType.LOGIN_WITH_GOOGLE
+        ? [upgradeCommand]
+        : []),
     ];
     handle?.end();
     return allDefinitions.filter((cmd): cmd is SlashCommand => cmd !== null);

packages/cli/src/ui/commands/upgradeCommand.test.ts

@@ -0,0 +1,99 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { upgradeCommand } from './upgradeCommand.js';
+import { type CommandContext } from './types.js';
+import { createMockCommandContext } from '../../test-utils/mockCommandContext.js';
+import {
+  AuthType,
+  openBrowserSecurely,
+  UPGRADE_URL_PAGE,
+} from '@google/gemini-cli-core';
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    openBrowserSecurely: vi.fn(),
+    UPGRADE_URL_PAGE: 'https://goo.gle/set-up-gemini-code-assist',
+  };
+});
+
+describe('upgradeCommand', () => {
+  let mockContext: CommandContext;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockContext = createMockCommandContext({
+      services: {
+        config: {
+          getContentGeneratorConfig: vi.fn().mockReturnValue({
+            authType: AuthType.LOGIN_WITH_GOOGLE,
+          }),
+        },
+      },
+    } as unknown as CommandContext);
+  });
+
+  it('should have the correct name and description', () => {
+    expect(upgradeCommand.name).toBe('upgrade');
+    expect(upgradeCommand.description).toBe(
+      'Upgrade your Gemini Code Assist tier for higher limits',
+    );
+  });
+
+  it('should call openBrowserSecurely with UPGRADE_URL_PAGE when logged in with Google', async () => {
+    if (!upgradeCommand.action) {
+      throw new Error('The upgrade command must have an action.');
+    }
+
+    await upgradeCommand.action(mockContext, '');
+
+    expect(openBrowserSecurely).toHaveBeenCalledWith(UPGRADE_URL_PAGE);
+  });
+
+  it('should return an error message when NOT logged in with Google', async () => {
+    vi.mocked(
+      mockContext.services.config!.getContentGeneratorConfig,
+    ).mockReturnValue({
+      authType: AuthType.USE_GEMINI,
+    });
+
+    if (!upgradeCommand.action) {
+      throw new Error('The upgrade command must have an action.');
+    }
+
+    const result = await upgradeCommand.action(mockContext, '');
+
+    expect(result).toEqual({
+      type: 'message',
+      messageType: 'error',
+      content:
+        'The /upgrade command is only available when logged in with Google.',
+    });
+    expect(openBrowserSecurely).not.toHaveBeenCalled();
+  });
+
+  it('should return an error message if openBrowserSecurely fails', async () => {
+    vi.mocked(openBrowserSecurely).mockRejectedValue(
+      new Error('Failed to open'),
+    );
+
+    if (!upgradeCommand.action) {
+      throw new Error('The upgrade command must have an action.');
+    }
+
+    const result = await upgradeCommand.action(mockContext, '');
+
+    expect(result).toEqual({
+      type: 'message',
+      messageType: 'error',
+      content: 'Failed to open upgrade page: Failed to open',
+    });
+  });
+});

packages/cli/src/ui/commands/upgradeCommand.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  AuthType,
+  openBrowserSecurely,
+  UPGRADE_URL_PAGE,
+} from '@google/gemini-cli-core';
+import type { SlashCommand } from './types.js';
+import { CommandKind } from './types.js';
+
+/**
+ * Command to open the upgrade page for Gemini Code Assist.
+ * Only intended to be shown/available when the user is logged in with Google.
+ */
+export const upgradeCommand: SlashCommand = {
+  name: 'upgrade',
+  kind: CommandKind.BUILT_IN,
+  description: 'Upgrade your Gemini Code Assist tier for higher limits',
+  autoExecute: true,
+  action: async (context) => {
+    const authType =
+      context.services.config?.getContentGeneratorConfig()?.authType;
+    if (authType !== AuthType.LOGIN_WITH_GOOGLE) {
+      // This command should ideally be hidden if not logged in with Google,
+      // but we add a safety check here just in case.
+      return {
+        type: 'message',
+        messageType: 'error',
+        content:
+          'The /upgrade command is only available when logged in with Google.',
+      };
+    }
+
+    try {
+      await openBrowserSecurely(UPGRADE_URL_PAGE);
+    } catch (error) {
+      return {
+        type: 'message',
+        messageType: 'error',
+        content: `Failed to open upgrade page: ${error instanceof Error ? error.message : String(error)}`,
+      };
+    }
+
+    return undefined;
+  },
+};

packages/core/src/fallback/handler.ts

@@ -18,7 +18,7 @@ import {
   applyAvailabilityTransition,
 } from '../availability/policyHelpers.js';
 
-const UPGRADE_URL_PAGE = 'https://goo.gle/set-up-gemini-code-assist';
+export const UPGRADE_URL_PAGE = 'https://goo.gle/set-up-gemini-code-assist';
 
 export async function handleFallback(
   config: Config,

packages/core/src/index.ts

@@ -48,6 +48,7 @@ export * from './scheduler/tool-executor.js';
 export * from './core/recordingContentGenerator.js';
 
 export * from './fallback/types.js';
+export * from './fallback/handler.js';
 
 export * from './code_assist/codeAssist.js';
 export * from './code_assist/oauth2.js';