fix(patch): cherry-pick f08b4af to release/v0.45.2-pr-27749 to patch version v0.45.2 and create version 0.45.3

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

@@ -12,7 +12,12 @@ import { MessageType } from '../types.js';
 
 describe('helpCommand', () => {
   let mockContext: CommandContext;
-  const originalEnv = { ...process.env };
+  const originalPlatform = process.platform;
+  const action = helpCommand.action;
+
+  if (!action) {
+    throw new Error('Help command has no action');
+  }
 
   beforeEach(() => {
     mockContext = createMockCommandContext({
@@ -23,16 +28,13 @@ describe('helpCommand', () => {
   });
 
   afterEach(() => {
-    process.env = { ...originalEnv };
+    Object.defineProperty(process, 'platform', { value: originalPlatform });
+    vi.unstubAllEnvs();
     vi.clearAllMocks();
   });
 
-  it('should add a help message to the UI history', async () => {
-    if (!helpCommand.action) {
-      throw new Error('Help command has no action');
-    }
-
-    await helpCommand.action(mockContext, '');
+  it('should add a help message to the UI history by default', async () => {
+    await action(mockContext, '');
 
     expect(mockContext.ui.addItem).toHaveBeenCalledWith(
       expect.objectContaining({
@@ -47,4 +49,85 @@ describe('helpCommand', () => {
     expect(helpCommand.kind).toBe(CommandKind.BUILT_IN);
     expect(helpCommand.description).toBe('For help on gemini-cli');
   });
+
+  describe('Antigravity installer commands help', () => {
+    it('should output macOS installation command on darwin platform', async () => {
+      Object.defineProperty(process, 'platform', { value: 'darwin' });
+
+      await action(mockContext, 'install antigravity cli');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: `To install the Antigravity CLI on macOS, run the following command:\n\n'curl -fsSL https://antigravity.google/cli/install.sh | bash'`,
+        }),
+      );
+    });
+
+    it('should output Linux installation command on linux platform', async () => {
+      Object.defineProperty(process, 'platform', { value: 'linux' });
+
+      await action(mockContext, 'how do I install antigravity CLI');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: `To install the Antigravity CLI on Linux, run the following command:\n\n'curl -fsSL https://antigravity.google/cli/install.sh | bash'`,
+        }),
+      );
+    });
+
+    it('should output Windows PowerShell installation command on win32 when PSModulePath is set', async () => {
+      Object.defineProperty(process, 'platform', { value: 'win32' });
+      vi.stubEnv('PSModulePath', 'C:\\some\\path');
+
+      await action(mockContext, 'how do I migrate to antigravity CLI');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: `To install the Antigravity CLI on Windows (PowerShell), run the following command:\n\n'irm https://antigravity.google/cli/install.ps1 | iex'`,
+        }),
+      );
+    });
+
+    it('should output Windows CMD installation command on win32 when PSModulePath is not set', async () => {
+      Object.defineProperty(process, 'platform', { value: 'win32' });
+      vi.stubEnv('PSModulePath', '');
+
+      await action(mockContext, 'install antigravity cli');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: `To install the Antigravity CLI on Windows (Command Prompt), run the following command:\n\n'curl -fsSL https://antigravity.google/cli/install.cmd -o install.cmd && install.cmd && del install.cmd'`,
+        }),
+      );
+    });
+
+    it('should learn more message on unsupported platform', async () => {
+      Object.defineProperty(process, 'platform', { value: 'freebsd' });
+
+      await action(mockContext, 'install antigravity cli');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: 'Learn more about Antigravity CLI at https://antigravity.google/docs/cli-getting-started',
+        }),
+      );
+    });
+
+    it('should fall back to default help if query does not contain install or migrate', async () => {
+      Object.defineProperty(process, 'platform', { value: 'darwin' });
+
+      await action(mockContext, 'antigravity cli');
+
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: MessageType.HELP,
+        }),
+      );
+    });
+  });
 });

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

@@ -6,13 +6,36 @@
 
 import { CommandKind, type SlashCommand } from './types.js';
 import { MessageType, type HistoryItemHelp } from '../types.js';
+import { getAntigravityInstallInfo } from '../utils/antigravityUtils.js';
 
 export const helpCommand: SlashCommand = {
   name: 'help',
   kind: CommandKind.BUILT_IN,
   description: 'For help on gemini-cli',
   autoExecute: true,
-  action: async (context) => {
+  action: async (context, args) => {
+    const lowerArgs = args?.toLowerCase() || '';
+    const hasAntigravity = lowerArgs.includes('antigravity');
+    const hasInstallOrMigrate =
+      lowerArgs.includes('install') || lowerArgs.includes('migrate');
+
+    if (hasAntigravity && hasInstallOrMigrate) {
+      const info = getAntigravityInstallInfo();
+
+      if (info) {
+        context.ui.addItem({
+          type: MessageType.INFO,
+          text: `To install the Antigravity CLI on ${info.platformName}, run the following command:\n\n'${info.installCmd}'`,
+        });
+      } else {
+        context.ui.addItem({
+          type: MessageType.INFO,
+          text: `Learn more about Antigravity CLI at https://antigravity.google/docs/cli-getting-started`,
+        });
+      }
+      return;
+    }
+
     const helpItem: Omit<HistoryItemHelp, 'id'> = {
       type: MessageType.HELP,
       timestamp: new Date(),

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

@@ -10,12 +10,14 @@ import {
   expect,
   vi,
   beforeEach,
+  afterEach,
   type MockedFunction,
 } from 'vitest';
 import { renderHook } from '../../test-utils/render.js';
 import { useBanner, _clearSessionBannersForTest } from './useBanner.js';
 import { persistentState } from '../../utils/persistentState.js';
 import crypto from 'node:crypto';
+import chalk from 'chalk';
 
 vi.mock('../../utils/persistentState.js', () => ({
   persistentState: {
@@ -94,7 +96,9 @@ describe('useBanner', () => {
 
     const { result } = await renderHook(() => useBanner(antigravityBannerData));
 
-    expect(result.current.bannerText).toBe('Antigravity is coming to town!');
+    expect(result.current.bannerText).toContain(
+      'Antigravity is coming to town!',
+    );
   });
 
   it('should increment the persistent count when banner is shown', async () => {
@@ -137,4 +141,77 @@ describe('useBanner', () => {
 
     expect(result.current.bannerText).toBe('Line1\nLine2');
   });
+
+  describe('Antigravity installation commands', () => {
+    const originalPlatform = process.platform;
+
+    afterEach(() => {
+      Object.defineProperty(process, 'platform', { value: originalPlatform });
+      vi.unstubAllEnvs();
+    });
+
+    it('should append macOS & Linux install command when on darwin', async () => {
+      Object.defineProperty(process, 'platform', { value: 'darwin' });
+      const data = { defaultText: 'Welcome to Antigravity!', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe(
+        `Welcome to Antigravity!\n \nTo install run "${chalk.bold('curl -fsSL https://antigravity.google/cli/install.sh | bash')}"`,
+      );
+    });
+
+    it('should append macOS & Linux install command when on linux', async () => {
+      Object.defineProperty(process, 'platform', { value: 'linux' });
+      const data = { defaultText: 'Welcome to Antigravity!', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe(
+        `Welcome to Antigravity!\n \nTo install run "${chalk.bold('curl -fsSL https://antigravity.google/cli/install.sh | bash')}"`,
+      );
+    });
+
+    it('should append Windows PowerShell install command when on win32 and PSModulePath is set', async () => {
+      Object.defineProperty(process, 'platform', { value: 'win32' });
+      vi.stubEnv('PSModulePath', 'C:\\some\\path');
+      const data = { defaultText: 'Welcome to Antigravity!', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe(
+        `Welcome to Antigravity!\n \nTo install run "${chalk.bold('irm https://antigravity.google/cli/install.ps1 | iex')}"`,
+      );
+    });
+
+    it('should append Windows CMD install command when on win32 and PSModulePath is not set', async () => {
+      Object.defineProperty(process, 'platform', { value: 'win32' });
+      vi.stubEnv('PSModulePath', '');
+      const data = { defaultText: 'Welcome to Antigravity!', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe(
+        `Welcome to Antigravity!\n \nTo install run "${chalk.bold('curl -fsSL https://antigravity.google/cli/install.cmd -o install.cmd && install.cmd && del install.cmd')}"`,
+      );
+    });
+
+    it('should not append install command if banner text does not contain Antigravity', async () => {
+      Object.defineProperty(process, 'platform', { value: 'darwin' });
+      const data = { defaultText: 'Regular Banner', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe('Regular Banner');
+    });
+
+    it('should not append install command if process.platform is an unsupported platform', async () => {
+      Object.defineProperty(process, 'platform', { value: 'freebsd' });
+      const data = { defaultText: 'Welcome to Antigravity!', warningText: '' };
+
+      const { result } = await renderHook(() => useBanner(data));
+
+      expect(result.current.bannerText).toBe('Welcome to Antigravity!');
+    });
+  });
 });

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

@@ -7,6 +7,8 @@
 import { useState, useEffect } from 'react';
 import { persistentState } from '../../utils/persistentState.js';
 import crypto from 'node:crypto';
+import chalk from 'chalk';
+import { getAntigravityInstallInfo } from '../utils/antigravityUtils.js';
 
 const DEFAULT_MAX_BANNER_SHOWN_COUNT = 5;
 
@@ -46,7 +48,14 @@ export function useBanner(bannerData: BannerData) {
       activeText.includes('Antigravity'));
 
   const rawBannerText = showBanner ? activeText : '';
-  const bannerText = rawBannerText.replace(/\\n/g, '\n');
+  let bannerText = rawBannerText.replace(/\\n/g, '\n');
+
+  if (showBanner && activeText.includes('Antigravity')) {
+    const info = getAntigravityInstallInfo();
+    if (info) {
+      bannerText += `\n \nTo install run "${chalk.bold(info.installCmd)}"`;
+    }
+  }
 
   useEffect(() => {
     if (showBanner && activeText) {

packages/cli/src/ui/utils/antigravityUtils.test.ts

@@ -0,0 +1,72 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { getAntigravityInstallInfo } from './antigravityUtils.js';
+
+describe('antigravityUtils', () => {
+  const originalPlatform = process.platform;
+
+  afterEach(() => {
+    Object.defineProperty(process, 'platform', { value: originalPlatform });
+    vi.unstubAllEnvs();
+  });
+
+  it('should return macOS installation info on darwin platform', () => {
+    Object.defineProperty(process, 'platform', { value: 'darwin' });
+
+    const info = getAntigravityInstallInfo();
+
+    expect(info).toEqual({
+      platformName: 'macOS',
+      installCmd: 'curl -fsSL https://antigravity.google/cli/install.sh | bash',
+    });
+  });
+
+  it('should return Linux installation info on linux platform', () => {
+    Object.defineProperty(process, 'platform', { value: 'linux' });
+
+    const info = getAntigravityInstallInfo();
+
+    expect(info).toEqual({
+      platformName: 'Linux',
+      installCmd: 'curl -fsSL https://antigravity.google/cli/install.sh | bash',
+    });
+  });
+
+  it('should return Windows PowerShell installation info on win32 when PSModulePath is set', () => {
+    Object.defineProperty(process, 'platform', { value: 'win32' });
+    vi.stubEnv('PSModulePath', 'C:\\some\\path');
+
+    const info = getAntigravityInstallInfo();
+
+    expect(info).toEqual({
+      platformName: 'Windows (PowerShell)',
+      installCmd: 'irm https://antigravity.google/cli/install.ps1 | iex',
+    });
+  });
+
+  it('should return Windows CMD installation info on win32 when PSModulePath is not set', () => {
+    Object.defineProperty(process, 'platform', { value: 'win32' });
+    vi.stubEnv('PSModulePath', '');
+
+    const info = getAntigravityInstallInfo();
+
+    expect(info).toEqual({
+      platformName: 'Windows (Command Prompt)',
+      installCmd:
+        'curl -fsSL https://antigravity.google/cli/install.cmd -o install.cmd && install.cmd && del install.cmd',
+    });
+  });
+
+  it('should return null on unsupported platform', () => {
+    Object.defineProperty(process, 'platform', { value: 'freebsd' });
+
+    const info = getAntigravityInstallInfo();
+
+    expect(info).toBeNull();
+  });
+});