[pull] main from microsoft:main

resources/profiles/agent-sessions.code-profile

@@ -2,27 +2,29 @@
 	"name": "Agent Sessions",
 	"icon": "vscode",
 	"settings": {
-	"workbench.statusBar.visible": false,
-	"workbench.activityBar.location": "hidden",
-	"workbench.sideBar.location": "right",
-	"workbench.secondarySideBar.defaultVisibility": "maximized",
-	"workbench.secondarySideBar.restoreMaximized": true,
-	"chat.restoreLastPanelSession": true,
-	"workbench.startupEditor": "none",
-	"workbench.editor.restoreEditors": false,
-	"chat.agentsControl.enabled": true,
-	"chat.unifiedAgentsBar.enabled": true,
-	"files.autoSave": "afterDelay",
-	"window.title": "Agent Sessions",
-	"workbench.editor.showTabs": "single",
-	"workbench.colorTheme": "2026-dark-experimental",
-	"chat.agentsControl.triStateToggle": true,
-	"workbench.tips.enabled": false,
-	"chat.agent.maxRequests": 1000,
-	"workbench.layoutControl.type": "toggles",
-	"inlineChat.affordance": "editor",
-	"inlineChat.renderMode": "hover",
-	"github.copilot.chat.claudeCode.enabled": true,
-	"github.copilot.chat.languageContext.typescript.enabled": true
+		"workbench.statusBar.visible": false,
+		"workbench.activityBar.location": "hidden",
+		"workbench.sideBar.location": "right",
+		"workbench.secondarySideBar.defaultVisibility": "maximized",
+		"workbench.secondarySideBar.restoreMaximized": true,
+		"chat.restoreLastPanelSession": true,
+		"workbench.startupEditor": "none",
+		"workbench.editor.restoreEditors": false,
+		"chat.agentsControl.enabled": true,
+		"chat.unifiedAgentsBar.enabled": true,
+		"files.autoSave": "afterDelay",
+		"window.title": "Agent Sessions",
+		"workbench.editor.showTabs": "single",
+		"workbench.colorTheme": "2026-dark-experimental",
+		"chat.agentsControl.triStateToggle": true,
+		"workbench.tips.enabled": false,
+		"chat.agent.maxRequests": 1000,
+		"workbench.layoutControl.type": "toggles",
+		"inlineChat.affordance": "editor",
+		"inlineChat.renderMode": "hover",
+		"github.copilot.chat.claudeCode.enabled": true,
+		"github.copilot.chat.languageContext.typescript.enabled": true,
+		"diffEditor.renderSideBySide": false,
+		"diffEditor.hideUnchangedRegions.enabled": true
 	}
 }

src/vs/workbench/api/browser/mainThreadChatSessions.ts

@@ -348,14 +348,15 @@ export class MainThreadChatSessions extends Disposable implements MainThreadChat
 
 		this._proxy = this._extHostContext.getProxy(ExtHostContext.ExtHostChatSessions);
 
-		this._chatSessionsService.setOptionsChangeCallback(async (sessionResource: URI, updates: ReadonlyArray<{ optionId: string; value: string | IChatSessionProviderOptionItem }>) => {
+		this._register(this._chatSessionsService.onRequestNotifyExtension(({ sessionResource, updates, waitUntil }) => {
 			const handle = this._getHandleForSessionType(sessionResource.scheme);
+			this._logService.trace(`[MainThreadChatSessions] onRequestNotifyExtension received: scheme '${sessionResource.scheme}', handle ${handle}, ${updates.length} update(s)`);
 			if (handle !== undefined) {
-				await this.notifyOptionsChange(handle, sessionResource, updates);
+				waitUntil(this.notifyOptionsChange(handle, sessionResource, updates));
 			} else {
 				this._logService.warn(`[MainThreadChatSessions] Cannot notify option change for scheme '${sessionResource.scheme}': no provider registered. Registered schemes: [${Array.from(this._sessionTypeToHandle.keys()).join(', ')}]`);
 			}
-		});
+		}));
 
 		this._register(this._agentSessionsService.model.onDidChangeSessionArchivedState(session => {
 			for (const [handle, { provider }] of this._itemProvidersRegistrations) {
@@ -709,10 +710,12 @@ export class MainThreadChatSessions extends Disposable implements MainThreadChat
 	 * Notify the extension about option changes for a session
 	 */
 	async notifyOptionsChange(handle: number, sessionResource: URI, updates: ReadonlyArray<{ optionId: string; value: string | IChatSessionProviderOptionItem | undefined }>): Promise<void> {
+		this._logService.trace(`[MainThreadChatSessions] notifyOptionsChange: starting proxy call for handle ${handle}, sessionResource ${sessionResource}`);
 		try {
 			await this._proxy.$provideHandleOptionsChange(handle, sessionResource, updates, CancellationToken.None);
+			this._logService.trace(`[MainThreadChatSessions] notifyOptionsChange: proxy call completed for handle ${handle}, sessionResource ${sessionResource}`);
 		} catch (error) {
-			this._logService.error(`Error notifying extension about options change for handle ${handle}, sessionResource ${sessionResource}:`, error);
+			this._logService.error(`[MainThreadChatSessions] notifyOptionsChange: error for handle ${handle}, sessionResource ${sessionResource}:`, error);
 		}
 	}
 }

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

@@ -7,7 +7,7 @@ import { sep } from '../../../../../base/common/path.js';
 import { raceCancellationError } from '../../../../../base/common/async.js';
 import { CancellationToken } from '../../../../../base/common/cancellation.js';
 import { Codicon } from '../../../../../base/common/codicons.js';
-import { Emitter, Event } from '../../../../../base/common/event.js';
+import { AsyncEmitter, Emitter, Event } from '../../../../../base/common/event.js';
 import { combinedDisposable, Disposable, DisposableMap, DisposableStore, IDisposable, toDisposable } from '../../../../../base/common/lifecycle.js';
 import { ResourceMap } from '../../../../../base/common/map.js';
 import { Schemas } from '../../../../../base/common/network.js';
@@ -31,7 +31,7 @@ import { ExtensionsRegistry } from '../../../../services/extensions/common/exten
 import { ChatEditorInput } from '../widgetHosts/editor/chatEditorInput.js';
 import { IChatAgentAttachmentCapabilities, IChatAgentData, IChatAgentService } from '../../common/participants/chatAgents.js';
 import { ChatContextKeys } from '../../common/actions/chatContextKeys.js';
-import { IChatSession, IChatSessionContentProvider, IChatSessionItem, IChatSessionItemProvider, IChatSessionProviderOptionGroup, IChatSessionProviderOptionItem, IChatSessionsExtensionPoint, IChatSessionsService, isSessionInProgressStatus, SessionOptionsChangedCallback } from '../../common/chatSessionsService.js';
+import { IChatSession, IChatSessionContentProvider, IChatSessionItem, IChatSessionItemProvider, IChatSessionOptionsWillNotifyExtensionEvent, IChatSessionProviderOptionGroup, IChatSessionProviderOptionItem, IChatSessionsExtensionPoint, IChatSessionsService, isSessionInProgressStatus } from '../../common/chatSessionsService.js';
 import { ChatAgentLocation, ChatModeKind } from '../../common/constants.js';
 import { CHAT_CATEGORY } from '../actions/chatActions.js';
 import { IChatEditorOptions } from '../widgetHosts/editor/chatEditor.js';
@@ -277,6 +277,8 @@ export class ChatSessionsService extends Disposable implements IChatSessionsServ
 	public get onDidChangeSessionOptions() { return this._onDidChangeSessionOptions.event; }
 	private readonly _onDidChangeOptionGroups = this._register(new Emitter<string>());
 	public get onDidChangeOptionGroups() { return this._onDidChangeOptionGroups.event; }
+	private readonly _onRequestNotifyExtension = this._register(new AsyncEmitter<IChatSessionOptionsWillNotifyExtensionEvent>());
+	public get onRequestNotifyExtension() { return this._onRequestNotifyExtension.event; }
 
 	private readonly inProgressMap: Map<string, number> = new Map();
 	private readonly _sessionTypeOptions: Map<string, IChatSessionProviderOptionGroup[]> = new Map();
@@ -1030,29 +1032,23 @@ export class ChatSessionsService extends Disposable implements IChatSessionsServ
 		return this._sessionTypeOptions.get(chatSessionType);
 	}
 
-	private _optionsChangeCallback?: SessionOptionsChangedCallback;
-
-	/**
-	 * Set the callback for notifying extensions about option changes
-	 */
-	public setOptionsChangeCallback(callback: SessionOptionsChangedCallback): void {
-		this._optionsChangeCallback = callback;
-	}
-
 	/**
 	 * Notify extension about option changes for a session
 	 */
 	public async notifySessionOptionsChange(sessionResource: URI, updates: ReadonlyArray<{ optionId: string; value: string | IChatSessionProviderOptionItem }>): Promise<void> {
 		if (!updates.length) {
 			return;
 		}
-		if (this._optionsChangeCallback) {
-			await this._optionsChangeCallback(sessionResource, updates);
-		}
+		this._logService.trace(`[ChatSessionsService] notifySessionOptionsChange: starting for ${sessionResource}, ${updates.length} update(s): [${updates.map(u => u.optionId).join(', ')}]`);
+		// Fire event to notify MainThreadChatSessions (which forwards to extension host)
+		// Uses fireAsync to properly await async listener work via waitUntil pattern
+		await this._onRequestNotifyExtension.fireAsync({ sessionResource, updates }, CancellationToken.None);
+		this._logService.trace(`[ChatSessionsService] notifySessionOptionsChange: fireAsync completed for ${sessionResource}`);
 		for (const u of updates) {
 			this.setSessionOption(sessionResource, u.optionId, u.value);
 		}
 		this._onDidChangeSessionOptions.fire(sessionResource);
+		this._logService.trace(`[ChatSessionsService] notifySessionOptionsChange: finished for ${sessionResource}`);
 	}
 
 	/**

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

@@ -6,6 +6,7 @@
 import * as dom from '../../../../../../base/browser/dom.js';
 import { $, AnimationFrameScheduler, DisposableResizeObserver } from '../../../../../../base/browser/dom.js';
 import { Codicon } from '../../../../../../base/common/codicons.js';
+import { IDisposable } from '../../../../../../base/common/lifecycle.js';
 import { ThemeIcon } from '../../../../../../base/common/themables.js';
 import { rcut } from '../../../../../../base/common/strings.js';
 import { localize } from '../../../../../../nls.js';
@@ -17,7 +18,7 @@ import { ChatTreeItem } from '../../chat.js';
 import { IChatContentPart, IChatContentPartRenderContext } from './chatContentParts.js';
 import { ChatCollapsibleContentPart } from './chatCollapsibleContentPart.js';
 import { ChatCollapsibleMarkdownContentPart } from './chatCollapsibleMarkdownContentPart.js';
-import { IChatToolInvocation, IChatToolInvocationSerialized } from '../../../common/chatService/chatService.js';
+import { IChatMarkdownContent, IChatToolInvocation, IChatToolInvocationSerialized } from '../../../common/chatService/chatService.js';
 import { IRunSubagentToolInputParams, RunSubagentTool } from '../../../common/tools/builtinTools/runSubagentTool.js';
 import { autorun } from '../../../../../../base/common/observable.js';
 import { Lazy } from '../../../../../../base/common/lazy.js';
@@ -36,11 +37,22 @@ const MAX_TITLE_LENGTH = 100;
  * Represents a lazy tool item that will be created when the subagent section is expanded.
  */
 interface ILazyToolItem {
+	kind: 'tool';
 	lazy: Lazy<ChatToolInvocationPart>;
 	toolInvocation: IChatToolInvocation | IChatToolInvocationSerialized;
 	codeBlockStartIndex: number;
 }
 
+/**
+ * Represents a lazy markdown item (e.g., edit pill) that will be rendered when expanded.
+ */
+interface ILazyMarkdownItem {
+	kind: 'markdown';
+	lazy: Lazy<{ domNode: HTMLElement; disposable?: IDisposable }>;
+}
+
+type ILazyItem = ILazyToolItem | ILazyMarkdownItem;
+
 /**
  * This is generally copied from ChatThinkingContentPart. We are still experimenting with both UIs so I'm not
  * trying to refactor to share code. Both could probably be simplified when stable.
@@ -59,7 +71,7 @@ export class ChatSubagentContentPart extends ChatCollapsibleContentPart implemen
 	private prompt: string | undefined;
 
 	// Lazy rendering support
-	private readonly lazyItems: ILazyToolItem[] = [];
+	private readonly lazyItems: ILazyItem[] = [];
 	private hasExpandedOnce: boolean = false;
 	private pendingPromptRender: boolean = false;
 	private pendingResultText: string | undefined;
@@ -500,6 +512,7 @@ export class ChatSubagentContentPart extends ChatCollapsibleContentPart implemen
 		} else {
 			// Defer rendering until expanded
 			const item: ILazyToolItem = {
+				kind: 'tool',
 				lazy: new Lazy(() => this.createToolPart(toolInvocation, codeBlockStartIndex)),
 				toolInvocation,
 				codeBlockStartIndex,
@@ -508,6 +521,61 @@ export class ChatSubagentContentPart extends ChatCollapsibleContentPart implemen
 		}
 	}
 
+	/**
+	 * Appends a markdown item (e.g., an edit pill) to the subagent content part.
+	 * This is used to route codeblockUri parts with subAgentInvocationId to this subagent's container.
+	 */
+	public appendMarkdownItem(
+		factory: () => { domNode: HTMLElement; disposable?: IDisposable },
+		_codeblocksPartId: string | undefined,
+		_markdown: IChatMarkdownContent,
+		_originalParent?: HTMLElement
+	): void {
+		// If expanded or has been expanded once, render immediately
+		if (this.isExpanded() || this.hasExpandedOnce) {
+			const result = factory();
+			this.appendMarkdownItemToDOM(result.domNode);
+			if (result.disposable) {
+				this._register(result.disposable);
+			}
+		} else {
+			// Defer rendering until expanded
+			const item: ILazyMarkdownItem = {
+				kind: 'markdown',
+				lazy: new Lazy(factory),
+			};
+			this.lazyItems.push(item);
+		}
+	}
+
+	/**
+	 * Appends a markdown item's DOM node to the wrapper.
+	 */
+	private appendMarkdownItemToDOM(domNode: HTMLElement): void {
+		if (!domNode.hasChildNodes() || domNode.textContent?.trim() === '') {
+			return;
+		}
+
+		// Wrap with icon like other items
+		const itemWrapper = $('.chat-thinking-tool-wrapper');
+		const iconElement = createThinkingIcon(Codicon.edit);
+		itemWrapper.appendChild(domNode);
+		itemWrapper.insertBefore(iconElement, itemWrapper.firstChild);
+
+		// Insert before result container if it exists, otherwise append
+		if (this.wrapper) {
+			if (this.resultContainer) {
+				this.wrapper.insertBefore(itemWrapper, this.resultContainer);
+			} else {
+				this.wrapper.appendChild(itemWrapper);
+			}
+		}
+		this.lastItemWrapper = itemWrapper;
+
+		// Schedule layout to measure last item and scroll
+		this.layoutScheduler.schedule();
+	}
+
 	protected override shouldInitEarly(): boolean {
 		// Never init early - subagent is collapsed while running, content only shown on expand
 		return false;
@@ -582,15 +650,23 @@ export class ChatSubagentContentPart extends ChatCollapsibleContentPart implemen
 	}
 
 	/**
-	 * Materializes a lazy tool item by creating the tool part and adding it to the DOM.
+	 * Materializes a lazy item by creating the content and adding it to the DOM.
 	 */
-	private materializeLazyItem(item: ILazyToolItem): void {
+	private materializeLazyItem(item: ILazyItem): void {
 		if (item.lazy.hasValue) {
 			return; // Already materialized
 		}
 
-		const part = item.lazy.value;
-		this.appendToolPartToDOM(part, item.toolInvocation);
+		if (item.kind === 'tool') {
+			const part = item.lazy.value;
+			this.appendToolPartToDOM(part, item.toolInvocation);
+		} else if (item.kind === 'markdown') {
+			const result = item.lazy.value;
+			this.appendMarkdownItemToDOM(result.domNode);
+			if (result.disposable) {
+				this._register(result.disposable);
+			}
+		}
 	}
 
 	/**
@@ -640,6 +716,10 @@ export class ChatSubagentContentPart extends ChatCollapsibleContentPart implemen
 	}
 
 	hasSameContent(other: IChatRendererContent, _followingContent: IChatRendererContent[], _element: ChatTreeItem): boolean {
+		if (other.kind === 'markdownContent') {
+			return true;
+		}
+
 		// Match subagent tool invocations with the same subAgentInvocationId to keep them grouped
 		if ((other.kind === 'toolInvocation' || other.kind === 'toolInvocationSerialized') && (other.subAgentInvocationId || other.toolId === RunSubagentTool.Id)) {
 			// For runSubagent tool, use toolCallId as the effective ID

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/media/chatThinkingContent.css

@@ -242,5 +242,5 @@
 .interactive-session .interactive-response .value .chat-thinking-box .chat-used-context-label code {
 	display: inline;
 	line-height: inherit;
-	padding: 0 4px;
+	padding: 1px 3px;
 }

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

@@ -48,7 +48,7 @@ import { IThemeService } from '../../../../../platform/theme/common/themeService
 import { IChatEntitlementService } from '../../../../services/chat/common/chatEntitlementService.js';
 import { IWorkbenchIssueService } from '../../../issue/common/issue.js';
 import { CodiconActionViewItem } from '../../../notebook/browser/view/cellParts/cellActionView.js';
-import { annotateSpecialMarkdownContent, hasCodeblockUriTag } from '../../common/widget/annotations.js';
+import { annotateSpecialMarkdownContent, extractSubAgentInvocationIdFromText, hasCodeblockUriTag } from '../../common/widget/annotations.js';
 import { checkModeOption } from '../../common/chat.js';
 import { IChatAgentMetadata } from '../../common/participants/chatAgents.js';
 import { ChatContextKeys } from '../../common/actions/chatContextKeys.js';
@@ -1939,6 +1939,21 @@ export class ChatListItemRenderer extends Disposable implements ITreeRenderer<Ch
 			// append to thinking part when the codeblock is complete
 			const isComplete = this.isCodeblockComplete(markdown, context.element);
 
+			// Check if this markdown should be routed to a subagent content part
+			const subAgentInvocationId = extractSubAgentInvocationIdFromText(markdown.content.value);
+			if (subAgentInvocationId) {
+				const subagentPart = this.getSubagentPart(templateData.renderedParts, subAgentInvocationId);
+				if (subagentPart && markdownPart?.domNode && isComplete) {
+					subagentPart.appendMarkdownItem(
+						() => ({ domNode: markdownPart.domNode, disposable: markdownPart }),
+						markdownPart.codeblocksPartId,
+						markdown,
+						templateData.value
+					);
+					return subagentPart;
+				}
+			}
+
 			// create thinking part if it doesn't exist yet
 			const lastThinking = this.getLastThinkingPart(templateData.renderedParts);
 			if (!lastThinking && markdownPart?.domNode && this.shouldPinPart(markdown, context.element) && collapsedToolsMode === CollapsedToolsDisplayMode.Always && isComplete) {

src/vs/workbench/contrib/chat/browser/widget/media/chat.css

@@ -2076,6 +2076,7 @@ have to be updated for changes to the rules above, or to support more deeply nes
 	display: flex;
 	flex-direction: column;
 	gap: 2px;
+	line-height: 1.5em;
 }
 
 .interactive-response-progress-tree,
@@ -2173,6 +2174,7 @@ have to be updated for changes to the rules above, or to support more deeply nes
 .interactive-session .chat-used-context-label .monaco-button {
 	padding: 2px 6px 2px 2px;
 	font-size: var(--vscode-chat-font-size-body-m);
+	line-height: unset;
 }
 
 .interactive-session .chat-file-changes-label .monaco-button:hover {
@@ -2204,8 +2206,8 @@ have to be updated for changes to the rules above, or to support more deeply nes
 .interactive-item-container .progress-container {
 	display: flex;
 	align-items: center;
-	gap: 7px;
-	margin: 0 0 6px 4px;
+	gap: 4px;
+	margin: 0 0 6px 2px;
 
 	/* Tool calls transition from a progress to a collapsible list part, which needs to have this top padding.
 	The working progress also can be replaced by a tool progress part. So align this padding so the text doesn't appear to shift. */
@@ -2222,6 +2224,8 @@ have to be updated for changes to the rules above, or to support more deeply nes
 	.codicon {
 		/* Very aggressive list styles try to apply focus colors to every codicon in a list row. */
 		color: var(--vscode-icon-foreground) !important;
+		/* Matching the margin on all .monaco-text-button .codicon */
+		margin: 0 .2em;
 
 		&.codicon-error {
 			color: var(--vscode-editorError-foreground) !important;

src/vs/workbench/contrib/chat/common/chatService/chatService.ts

@@ -272,6 +272,7 @@ export interface IChatResponseCodeblockUriPart {
 	uri: URI;
 	isEdit?: boolean;
 	undoStopId?: string;
+	subAgentInvocationId?: string;
 }
 
 export interface IChatAgentMarkdownContentWithVulnerability {