chat: support MCP apps

src/vs/base/browser/touch.ts

@@ -122,13 +122,24 @@ export class Gesture extends Disposable {
 		return toDisposable(remove);
 	}
 
+	/**
+	 * Whether the device is able to represent touch events.
+	 */
 	@memoize
 	static isTouchDevice(): boolean {
 		// `'ontouchstart' in window` always evaluates to true with typescript's modern typings. This causes `window` to be
 		// `never` later in `window.navigator`. That's why we need the explicit `window as Window` cast
 		return 'ontouchstart' in mainWindow || navigator.maxTouchPoints > 0;
 	}
 
+	/**
+	 * Whether the device's primary input is able to hover.
+	 */
+	@memoize
+	static isHoverDevice(): boolean {
+		return mainWindow.matchMedia('(hover: hover)').matches;
+	}
+
 	public override dispose(): void {
 		if (this.handle) {
 			this.handle.dispose();

src/vs/platform/mcp/common/mcpManagement.ts

@@ -249,6 +249,7 @@ export const mcpAccessConfig = 'chat.mcp.access';
 export const mcpGalleryServiceUrlConfig = 'chat.mcp.gallery.serviceUrl';
 export const mcpGalleryServiceEnablementConfig = 'chat.mcp.gallery.enabled';
 export const mcpAutoStartConfig = 'chat.mcp.autostart';
+export const mcpAppsEnabledConfig = 'chat.mcp.apps.enabled';
 
 export interface IMcpGalleryConfig {
 	readonly serviceUrl?: string;

src/vs/workbench/contrib/chat/browser/chat.contribution.ts

@@ -19,7 +19,7 @@ import { Extensions as ConfigurationExtensions, ConfigurationScope, IConfigurati
 import { SyncDescriptor } from '../../../../platform/instantiation/common/descriptors.js';
 import { InstantiationType, registerSingleton } from '../../../../platform/instantiation/common/extensions.js';
 import { IInstantiationService } from '../../../../platform/instantiation/common/instantiation.js';
-import { McpAccessValue, McpAutoStartValue, mcpAccessConfig, mcpAutoStartConfig, mcpGalleryServiceEnablementConfig, mcpGalleryServiceUrlConfig } from '../../../../platform/mcp/common/mcpManagement.js';
+import { McpAccessValue, McpAutoStartValue, mcpAccessConfig, mcpAutoStartConfig, mcpGalleryServiceEnablementConfig, mcpGalleryServiceUrlConfig, mcpAppsEnabledConfig } from '../../../../platform/mcp/common/mcpManagement.js';
 import product from '../../../../platform/product/common/product.js';
 import { Registry } from '../../../../platform/registry/common/platform.js';
 import { EditorPaneDescriptor, IEditorPaneRegistry } from '../../../browser/editor.js';
@@ -465,6 +465,12 @@ configurationRegistry.registerConfiguration({
 			],
 			tags: ['experimental'],
 		},
+		[mcpAppsEnabledConfig]: {
+			type: 'boolean',
+			description: nls.localize('chat.mcp.ui.enabled', "Controls whether MCP servers can provide custom UI for tool invocations."),
+			default: false,
+			tags: ['experimental'],
+		},
 		[mcpServerSamplingSection]: {
 			type: 'object',
 			description: nls.localize('chat.mcp.serverSampling', "Configures which models are exposed to MCP servers for sampling (making model requests in the background). This setting can be edited in a graphical way under the `{0}` command.", 'MCP: ' + nls.localize('mcp.list', 'List Servers')),

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatContentParts.ts

@@ -8,6 +8,7 @@ import { ChatTreeItem, IChatCodeBlockInfo } from '../../chat.js';
 import { IChatRendererContent } from '../../../common/model/chatViewModel.js';
 import { CodeBlockModelCollection } from '../../../common/widget/codeBlockModelCollection.js';
 import { DiffEditorPool, EditorPool } from './chatContentCodePools.js';
+import { McpAppWebviewPool } from './toolInvocationParts/chatMcpAppWebviewPool.js';
 
 export interface IChatContentPart extends IDisposable {
 	domNode: HTMLElement | undefined;
@@ -29,6 +30,11 @@ export interface IChatContentPart extends IDisposable {
 	 */
 	hasSameContent(other: IChatRendererContent, followingContent: IChatRendererContent[], element: ChatTreeItem): boolean;
 
+	/**
+	 * Called when the content part is mounted to the DOM after being detached.
+	 */
+	onDidRemount?(): void;
+
 	addDisposable?(disposable: IDisposable): void;
 }
 
@@ -43,5 +49,6 @@ export interface IChatContentPartRenderContext {
 	readonly codeBlockStartIndex: number;
 	readonly diffEditorPool: DiffEditorPool;
 	readonly codeBlockModelCollection: CodeBlockModelCollection;
+	readonly mcpAppWebviewPool: McpAppWebviewPool;
 	currentWidth(): number;
 }

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/toolInvocationParts/chatInputOutputMarkdownProgressPart.ts

@@ -96,7 +96,7 @@ export class ChatInputOutputMarkdownProgressPart extends BaseChatToolInvocationS
 			this.getAutoApproveMessageContent(),
 			context,
 			toCodePart(input),
-			processedOutput && {
+			processedOutput && processedOutput.length > 0 ? {
 				parts: processedOutput.map((o, i): ChatCollapsibleIOPart => {
 					const permalinkBasename = o.type === 'ref' || o.uri
 						? basename(o.uri!)
@@ -124,7 +124,7 @@ export class ChatInputOutputMarkdownProgressPart extends BaseChatToolInvocationS
 						return { kind: 'data', value: decoded || new TextEncoder().encode(o.value), mimeType: o.mimeType, uri: permalinkUri, audience: o.audience };
 					}
 				}),
-			},
+			} : undefined,
 			isError,
 			ChatInputOutputMarkdownProgressPart._expandedByDefault.get(toolInvocation) ?? false,
 		));