diff --git a/packages/cli/src/commands/extensions/install.test.ts b/packages/cli/src/commands/extensions/install.test.ts
index 8f861246e6..d7cbaa1799 100644
--- a/packages/cli/src/commands/extensions/install.test.ts
+++ b/packages/cli/src/commands/extensions/install.test.ts
@@ -4,11 +4,23 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { describe, it, expect, vi, type MockInstance, type Mock } from 'vitest';
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type MockInstance,
+  type Mock,
+} from 'vitest';
 import { handleInstall, installCommand } from './install.js';
 import yargs from 'yargs';
 import { debugLogger, type GeminiCLIExtension } from '@google/gemini-cli-core';
-import type { ExtensionManager } from '../../config/extension-manager.js';
+import type {
+  ExtensionManager,
+  inferInstallMetadata,
+} from '../../config/extension-manager.js';
 import type { requestConsentNonInteractive } from '../../config/extensions/consent.js';
 import type * as fs from 'node:fs/promises';
 import type { Stats } from 'node:fs';
@@ -20,12 +32,15 @@ const mockRequestConsentNonInteractive: Mock<
   typeof requestConsentNonInteractive
 > = vi.hoisted(() => vi.fn());
 const mockStat: Mock<typeof fs.stat> = vi.hoisted(() => vi.fn());
+const mockInferInstallMetadata: Mock<typeof inferInstallMetadata> = vi.hoisted(
+  () => vi.fn(),
+);
 
 vi.mock('../../config/extensions/consent.js', () => ({
   requestConsentNonInteractive: mockRequestConsentNonInteractive,
 }));
 
-vi.mock('../../config/extension-manager.ts', async (importOriginal) => {
+vi.mock('../../config/extension-manager.js', async (importOriginal) => {
   const actual =
     await importOriginal<typeof import('../../config/extension-manager.js')>();
   return {
@@ -34,6 +49,7 @@ vi.mock('../../config/extension-manager.ts', async (importOriginal) => {
       installOrUpdateExtension: mockInstallOrUpdateExtension,
       loadExtensions: vi.fn(),
     })),
+    inferInstallMetadata: mockInferInstallMetadata,
   };
 });
 
@@ -72,12 +88,31 @@ describe('handleInstall', () => {
     processSpy = vi
       .spyOn(process, 'exit')
       .mockImplementation(() => undefined as never);
+
+    mockInferInstallMetadata.mockImplementation(async (source, args) => {
+      if (
+        source.startsWith('http://') ||
+        source.startsWith('https://') ||
+        source.startsWith('git@') ||
+        source.startsWith('sso://')
+      ) {
+        return {
+          source,
+          type: 'git',
+          ref: args?.ref,
+          autoUpdate: args?.autoUpdate,
+          allowPreRelease: args?.allowPreRelease,
+        };
+      }
+      return { source, type: 'local' };
+    });
   });
 
   afterEach(() => {
     mockInstallOrUpdateExtension.mockClear();
     mockRequestConsentNonInteractive.mockClear();
     mockStat.mockClear();
+    mockInferInstallMetadata.mockClear();
     vi.clearAllMocks();
   });
 
@@ -124,7 +159,9 @@ describe('handleInstall', () => {
   });
 
   it('throws an error from an unknown source', async () => {
-    mockStat.mockRejectedValue(new Error('ENOENT: no such file or directory'));
+    mockInferInstallMetadata.mockRejectedValue(
+      new Error('Install source not found.'),
+    );
     await handleInstall({
       source: 'test://google.com',
     });
diff --git a/packages/cli/src/commands/extensions/install.ts b/packages/cli/src/commands/extensions/install.ts
index 0420bd14f3..5830055024 100644
--- a/packages/cli/src/commands/extensions/install.ts
+++ b/packages/cli/src/commands/extensions/install.ts
@@ -5,17 +5,16 @@
  */
 
 import type { CommandModule } from 'yargs';
-import {
-  debugLogger,
-  type ExtensionInstallMetadata,
-} from '@google/gemini-cli-core';
+import { debugLogger } from '@google/gemini-cli-core';
 import { getErrorMessage } from '../../utils/errors.js';
-import { stat } from 'node:fs/promises';
 import {
   INSTALL_WARNING_MESSAGE,
   requestConsentNonInteractive,
 } from '../../config/extensions/consent.js';
-import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  ExtensionManager,
+  inferInstallMetadata,
+} from '../../config/extension-manager.js';
 import { loadSettings } from '../../config/settings.js';
 import { promptForSetting } from '../../config/extensions/extensionSettings.js';
 import { exitCli } from '../utils.js';
@@ -30,37 +29,12 @@ interface InstallArgs {
 
 export async function handleInstall(args: InstallArgs) {
   try {
-    let installMetadata: ExtensionInstallMetadata;
     const { source } = args;
-    if (
-      source.startsWith('http://') ||
-      source.startsWith('https://') ||
-      source.startsWith('git@') ||
-      source.startsWith('sso://')
-    ) {
-      installMetadata = {
-        source,
-        type: 'git',
-        ref: args.ref,
-        autoUpdate: args.autoUpdate,
-        allowPreRelease: args.allowPreRelease,
-      };
-    } else {
-      if (args.ref || args.autoUpdate) {
-        throw new Error(
-          '--ref and --auto-update are not applicable for local extensions.',
-        );
-      }
-      try {
-        await stat(source);
-        installMetadata = {
-          source,
-          type: 'local',
-        };
-      } catch {
-        throw new Error('Install source not found.');
-      }
-    }
+    const installMetadata = await inferInstallMetadata(source, {
+      ref: args.ref,
+      autoUpdate: args.autoUpdate,
+      allowPreRelease: args.allowPreRelease,
+    });
 
     const requestConsent = args.consent
       ? () => Promise.resolve(true)
diff --git a/packages/cli/src/commands/extensions/validate.test.ts b/packages/cli/src/commands/extensions/validate.test.ts
index 3d5aed0df5..d574095eb6 100644
--- a/packages/cli/src/commands/extensions/validate.test.ts
+++ b/packages/cli/src/commands/extensions/validate.test.ts
@@ -5,7 +5,15 @@
  */
 
 import * as fs from 'node:fs';
-import { describe, it, expect, vi, type MockInstance } from 'vitest';
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type MockInstance,
+} from 'vitest';
 import { handleValidate, validateCommand } from './validate.js';
 import yargs from 'yargs';
 import { createExtension } from '../../test-utils/createExtension.js';
diff --git a/packages/cli/src/config/extension-manager.ts b/packages/cli/src/config/extension-manager.ts
index 4547565df5..48cd17b873 100644
--- a/packages/cli/src/config/extension-manager.ts
+++ b/packages/cli/src/config/extension-manager.ts
@@ -7,6 +7,7 @@
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import * as os from 'node:os';
+import { stat } from 'node:fs/promises';
 import chalk from 'chalk';
 import { ExtensionEnablementManager } from './extensions/extensionEnablement.js';
 import { type Settings, SettingScope } from './settings.js';
@@ -198,7 +199,9 @@ export class ExtensionManager extends ExtensionLoader {
               installMetadata.type === 'git') ||
             // Otherwise ask the user if they would like to try a git clone.
             (await this.requestConsent(
-              `Error downloading github release for ${installMetadata.source} with the following error: ${result.errorMessage}.\n\nWould you like to attempt to install via "git clone" instead?`,
+              `Error downloading github release for ${installMetadata.source} with the following error: ${result.errorMessage}.
+
+Would you like to attempt to install via "git clone" instead?`,
             ))
           ) {
             await cloneFromGit(installMetadata, tempDir);
@@ -797,7 +800,46 @@ function validateName(name: string) {
   }
 }
 
-function getExtensionId(
+export async function inferInstallMetadata(
+  source: string,
+  args: {
+    ref?: string;
+    autoUpdate?: boolean;
+    allowPreRelease?: boolean;
+  } = {},
+): Promise<ExtensionInstallMetadata> {
+  if (
+    source.startsWith('http://') ||
+    source.startsWith('https://') ||
+    source.startsWith('git@') ||
+    source.startsWith('sso://')
+  ) {
+    return {
+      source,
+      type: 'git',
+      ref: args.ref,
+      autoUpdate: args.autoUpdate,
+      allowPreRelease: args.allowPreRelease,
+    };
+  } else {
+    if (args.ref || args.autoUpdate) {
+      throw new Error(
+        '--ref and --auto-update are not applicable for local extensions.',
+      );
+    }
+    try {
+      await stat(source);
+      return {
+        source,
+        type: 'local',
+      };
+    } catch {
+      throw new Error('Install source not found.');
+    }
+  }
+}
+
+export function getExtensionId(
   config: ExtensionConfig,
   installMetadata?: ExtensionInstallMetadata,
 ): string {
diff --git a/packages/cli/src/ui/commands/extensionsCommand.test.ts b/packages/cli/src/ui/commands/extensionsCommand.test.ts
index fbbd5d900d..4af145b631 100644
--- a/packages/cli/src/ui/commands/extensionsCommand.test.ts
+++ b/packages/cli/src/ui/commands/extensionsCommand.test.ts
@@ -26,9 +26,21 @@ import {
   type MockedFunction,
 } from 'vitest';
 import { type ExtensionUpdateAction } from '../state/extensions.js';
-import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  ExtensionManager,
+  inferInstallMetadata,
+} from '../../config/extension-manager.js';
 import { SettingScope } from '../../config/settings.js';
 
+vi.mock('../../config/extension-manager.js', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('../../config/extension-manager.js')>();
+  return {
+    ...actual,
+    inferInstallMetadata: vi.fn(),
+  };
+});
+
 import open from 'open';
 
 vi.mock('open', () => ({
@@ -42,6 +54,8 @@ vi.mock('../../config/extensions/update.js', () => ({
 
 const mockDisableExtension = vi.fn();
 const mockEnableExtension = vi.fn();
+const mockInstallExtension = vi.fn();
+const mockUninstallExtension = vi.fn();
 const mockGetExtensions = vi.fn();
 
 const inactiveExt: GeminiCLIExtension = {
@@ -102,6 +116,8 @@ describe('extensionsCommand', () => {
             Object.assign(actual, {
               enableExtension: mockEnableExtension,
               disableExtension: mockDisableExtension,
+              installOrUpdateExtension: mockInstallExtension,
+              uninstallExtension: mockUninstallExtension,
               getExtensions: mockGetExtensions,
             });
             return actual;
@@ -477,29 +493,189 @@ describe('extensionsCommand', () => {
   });
 
   describe('when enableExtensionReloading is true', () => {
-    it('should include enable and disable subcommands', () => {
+    it('should include enable, disable, install, and uninstall subcommands', () => {
       const command = extensionsCommand(true);
       const subCommandNames = command.subCommands?.map((cmd) => cmd.name);
       expect(subCommandNames).toContain('enable');
       expect(subCommandNames).toContain('disable');
+      expect(subCommandNames).toContain('install');
+      expect(subCommandNames).toContain('uninstall');
     });
   });
 
   describe('when enableExtensionReloading is false', () => {
-    it('should not include enable and disable subcommands', () => {
+    it('should not include enable, disable, install, and uninstall subcommands', () => {
       const command = extensionsCommand(false);
       const subCommandNames = command.subCommands?.map((cmd) => cmd.name);
       expect(subCommandNames).not.toContain('enable');
       expect(subCommandNames).not.toContain('disable');
+      expect(subCommandNames).not.toContain('install');
+      expect(subCommandNames).not.toContain('uninstall');
     });
   });
 
   describe('when enableExtensionReloading is not provided', () => {
-    it('should not include enable and disable subcommands by default', () => {
+    it('should not include enable, disable, install, and uninstall subcommands by default', () => {
       const command = extensionsCommand();
       const subCommandNames = command.subCommands?.map((cmd) => cmd.name);
       expect(subCommandNames).not.toContain('enable');
       expect(subCommandNames).not.toContain('disable');
+      expect(subCommandNames).not.toContain('install');
+      expect(subCommandNames).not.toContain('uninstall');
+    });
+  });
+
+  describe('install', () => {
+    let installAction: SlashCommand['action'];
+
+    beforeEach(() => {
+      installAction = extensionsCommand(true).subCommands?.find(
+        (cmd) => cmd.name === 'install',
+      )?.action;
+
+      expect(installAction).not.toBeNull();
+
+      mockContext.invocation!.name = 'install';
+    });
+
+    it('should show usage if no extension name is provided', async () => {
+      await installAction!(mockContext, '');
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.ERROR,
+          text: 'Usage: /extensions install <source>',
+        },
+        expect.any(Number),
+      );
+      expect(mockInstallExtension).not.toHaveBeenCalled();
+    });
+
+    it('should call installExtension and show success message', async () => {
+      const packageName = 'test-extension-package';
+      vi.mocked(inferInstallMetadata).mockResolvedValue({
+        source: packageName,
+        type: 'git',
+      });
+      mockInstallExtension.mockResolvedValue({ name: packageName });
+      await installAction!(mockContext, packageName);
+      expect(inferInstallMetadata).toHaveBeenCalledWith(packageName);
+      expect(mockInstallExtension).toHaveBeenCalledWith({
+        source: packageName,
+        type: 'git',
+      });
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.INFO,
+          text: `Installing extension from "${packageName}"...`,
+        },
+        expect.any(Number),
+      );
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.INFO,
+          text: `Extension "${packageName}" installed successfully.`,
+        },
+        expect.any(Number),
+      );
+    });
+
+    it('should show error message on installation failure', async () => {
+      const packageName = 'failed-extension';
+      const errorMessage = 'install failed';
+      vi.mocked(inferInstallMetadata).mockResolvedValue({
+        source: packageName,
+        type: 'git',
+      });
+      mockInstallExtension.mockRejectedValue(new Error(errorMessage));
+
+      await installAction!(mockContext, packageName);
+      expect(inferInstallMetadata).toHaveBeenCalledWith(packageName);
+      expect(mockInstallExtension).toHaveBeenCalledWith({
+        source: packageName,
+        type: 'git',
+      });
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.ERROR,
+          text: `Failed to install extension from "${packageName}": ${errorMessage}`,
+        },
+        expect.any(Number),
+      );
+    });
+
+    it('should show error message for invalid source', async () => {
+      const invalidSource = 'a;b';
+      await installAction!(mockContext, invalidSource);
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.ERROR,
+          text: `Invalid source: ${invalidSource}`,
+        },
+        expect.any(Number),
+      );
+      expect(mockInstallExtension).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('uninstall', () => {
+    let uninstallAction: SlashCommand['action'];
+
+    beforeEach(() => {
+      uninstallAction = extensionsCommand(true).subCommands?.find(
+        (cmd) => cmd.name === 'uninstall',
+      )?.action;
+
+      expect(uninstallAction).not.toBeNull();
+
+      mockContext.invocation!.name = 'uninstall';
+    });
+
+    it('should show usage if no extension name is provided', async () => {
+      await uninstallAction!(mockContext, '');
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.ERROR,
+          text: 'Usage: /extensions uninstall <extension-name>',
+        },
+        expect.any(Number),
+      );
+      expect(mockUninstallExtension).not.toHaveBeenCalled();
+    });
+
+    it('should call uninstallExtension and show success message', async () => {
+      const extensionName = 'test-extension';
+      await uninstallAction!(mockContext, extensionName);
+      expect(mockUninstallExtension).toHaveBeenCalledWith(extensionName, false);
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.INFO,
+          text: `Uninstalling extension "${extensionName}"...`,
+        },
+        expect.any(Number),
+      );
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.INFO,
+          text: `Extension "${extensionName}" uninstalled successfully.`,
+        },
+        expect.any(Number),
+      );
+    });
+
+    it('should show error message on uninstallation failure', async () => {
+      const extensionName = 'failed-extension';
+      const errorMessage = 'uninstall failed';
+      mockUninstallExtension.mockRejectedValue(new Error(errorMessage));
+
+      await uninstallAction!(mockContext, extensionName);
+      expect(mockUninstallExtension).toHaveBeenCalledWith(extensionName, false);
+      expect(mockContext.ui.addItem).toHaveBeenCalledWith(
+        {
+          type: MessageType.ERROR,
+          text: `Failed to uninstall extension "${extensionName}": ${errorMessage}`,
+        },
+        expect.any(Number),
+      );
     });
   });
 
diff --git a/packages/cli/src/ui/commands/extensionsCommand.ts b/packages/cli/src/ui/commands/extensionsCommand.ts
index 932eb55b2a..99ea05bccf 100644
--- a/packages/cli/src/ui/commands/extensionsCommand.ts
+++ b/packages/cli/src/ui/commands/extensionsCommand.ts
@@ -20,7 +20,10 @@ import {
 } from './types.js';
 import open from 'open';
 import process from 'node:process';
-import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  ExtensionManager,
+  inferInstallMetadata,
+} from '../../config/extension-manager.js';
 import { SettingScope } from '../../config/settings.js';
 import { theme } from '../semantic-colors.js';
 
@@ -429,6 +432,135 @@ async function enableAction(context: CommandContext, args: string) {
   }
 }
 
+async function installAction(context: CommandContext, args: string) {
+  const extensionLoader = context.services.config?.getExtensionLoader();
+  if (!(extensionLoader instanceof ExtensionManager)) {
+    debugLogger.error(
+      `Cannot ${context.invocation?.name} extensions in this environment`,
+    );
+    return;
+  }
+
+  const source = args.trim();
+  if (!source) {
+    context.ui.addItem(
+      {
+        type: MessageType.ERROR,
+        text: `Usage: /extensions install <source>`,
+      },
+      Date.now(),
+    );
+    return;
+  }
+
+  // Validate that the source is either a valid URL or a valid file path.
+  let isValid = false;
+  try {
+    // Check if it's a valid URL.
+    new URL(source);
+    isValid = true;
+  } catch {
+    // If not a URL, check for characters that are disallowed in file paths
+    // and could be used for command injection.
+    if (!/[;&|`'"]/.test(source)) {
+      isValid = true;
+    }
+  }
+
+  if (!isValid) {
+    context.ui.addItem(
+      {
+        type: MessageType.ERROR,
+        text: `Invalid source: ${source}`,
+      },
+      Date.now(),
+    );
+    return;
+  }
+
+  context.ui.addItem(
+    {
+      type: MessageType.INFO,
+      text: `Installing extension from "${source}"...`,
+    },
+    Date.now(),
+  );
+
+  try {
+    const installMetadata = await inferInstallMetadata(source);
+    const extension =
+      await extensionLoader.installOrUpdateExtension(installMetadata);
+    context.ui.addItem(
+      {
+        type: MessageType.INFO,
+        text: `Extension "${extension.name}" installed successfully.`,
+      },
+      Date.now(),
+    );
+  } catch (error) {
+    context.ui.addItem(
+      {
+        type: MessageType.ERROR,
+        text: `Failed to install extension from "${source}": ${getErrorMessage(
+          error,
+        )}`,
+      },
+      Date.now(),
+    );
+  }
+}
+
+async function uninstallAction(context: CommandContext, args: string) {
+  const extensionLoader = context.services.config?.getExtensionLoader();
+  if (!(extensionLoader instanceof ExtensionManager)) {
+    debugLogger.error(
+      `Cannot ${context.invocation?.name} extensions in this environment`,
+    );
+    return;
+  }
+
+  const name = args.trim();
+  if (!name) {
+    context.ui.addItem(
+      {
+        type: MessageType.ERROR,
+        text: `Usage: /extensions uninstall <extension-name>`,
+      },
+      Date.now(),
+    );
+    return;
+  }
+
+  context.ui.addItem(
+    {
+      type: MessageType.INFO,
+      text: `Uninstalling extension "${name}"...`,
+    },
+    Date.now(),
+  );
+
+  try {
+    await extensionLoader.uninstallExtension(name, false);
+    context.ui.addItem(
+      {
+        type: MessageType.INFO,
+        text: `Extension "${name}" uninstalled successfully.`,
+      },
+      Date.now(),
+    );
+  } catch (error) {
+    context.ui.addItem(
+      {
+        type: MessageType.ERROR,
+        text: `Failed to uninstall extension "${name}": ${getErrorMessage(
+          error,
+        )}`,
+      },
+      Date.now(),
+    );
+  }
+}
+
 /**
  * Exported for testing.
  */
@@ -505,6 +637,23 @@ const enableCommand: SlashCommand = {
   completion: completeExtensionsAndScopes,
 };
 
+const installCommand: SlashCommand = {
+  name: 'install',
+  description: 'Install an extension from a git repo or local path',
+  kind: CommandKind.BUILT_IN,
+  autoExecute: false,
+  action: installAction,
+};
+
+const uninstallCommand: SlashCommand = {
+  name: 'uninstall',
+  description: 'Uninstall an extension',
+  kind: CommandKind.BUILT_IN,
+  autoExecute: false,
+  action: uninstallAction,
+  completion: completeExtensions,
+};
+
 const exploreExtensionsCommand: SlashCommand = {
   name: 'explore',
   description: 'Open extensions page in your browser',
@@ -526,7 +675,7 @@ export function extensionsCommand(
   enableExtensionReloading?: boolean,
 ): SlashCommand {
   const conditionalCommands = enableExtensionReloading
-    ? [disableCommand, enableCommand]
+    ? [disableCommand, enableCommand, installCommand, uninstallCommand]
     : [];
   return {
     name: 'extensions',