sessions: suggest slash commands on new session page

src/vs/sessions/contrib/chat/browser/aiCustomizationWorkspaceService.ts

@@ -6,8 +6,9 @@
 import { derived, IObservable, observableValue, ISettableObservable } from '../../../../base/common/observable.js';
 import { joinPath } from '../../../../base/common/resources.js';
 import { URI } from '../../../../base/common/uri.js';
-import { IAICustomizationWorkspaceService, AICustomizationManagementSection, IStorageSourceFilter } from '../../../../workbench/contrib/chat/common/aiCustomizationWorkspaceService.js';
-import { PromptsStorage } from '../../../../workbench/contrib/chat/common/promptSyntax/service/promptsService.js';
+import { CancellationToken } from '../../../../base/common/cancellation.js';
+import { IAICustomizationWorkspaceService, AICustomizationManagementSection, IStorageSourceFilter, applyStorageSourceFilter } from '../../../../workbench/contrib/chat/common/aiCustomizationWorkspaceService.js';
+import { IChatPromptSlashCommand, IPromptsService, PromptsStorage } from '../../../../workbench/contrib/chat/common/promptSyntax/service/promptsService.js';
 import { ISessionsManagementService } from '../../sessions/browser/sessionsManagementService.js';
 import { IInstantiationService } from '../../../../platform/instantiation/common/instantiation.js';
 import { CustomizationCreatorService } from '../../../../workbench/contrib/chat/browser/aiCustomization/customizationCreatorService.js';
@@ -44,6 +45,7 @@ export class SessionsAICustomizationWorkspaceService implements IAICustomization
 	constructor(
 		@ISessionsManagementService private readonly sessionsService: ISessionsManagementService,
 		@IInstantiationService private readonly instantiationService: IInstantiationService,
+		@IPromptsService private readonly promptsService: IPromptsService,
 		@IPathService pathService: IPathService,
 	) {
 		const userHome = pathService.userHome({ preferLocal: true });
@@ -135,4 +137,12 @@ export class SessionsAICustomizationWorkspaceService implements IAICustomization
 		const creator = this.instantiationService.createInstance(CustomizationCreatorService);
 		await creator.createWithAI(type);
 	}
+
+	async getFilteredPromptSlashCommands(token: CancellationToken): Promise<readonly IChatPromptSlashCommand[]> {
+		const allCommands = await this.promptsService.getPromptSlashCommands(token);
+		return allCommands.filter(cmd => {
+			const filter = this.getStorageSourceFilter(cmd.promptPath.type);
+			return applyStorageSourceFilter([cmd.promptPath], filter).length > 0;
+		});
+	}
 }

src/vs/sessions/contrib/chat/browser/newChatViewPane.ts

@@ -948,7 +948,7 @@ class NewChatWidget extends Disposable implements IHistoryNavigationWidget {
 	}
 
 	private async _send(options?: { openNewAfterSend?: boolean }): Promise<void> {
-		const query = this._editor.getModel()?.getValue().trim();
+		let query = this._editor.getModel()?.getValue().trim();
 		const session = this._newSession.value;
 		if (!query || !session || this._sending) {
 			return;
@@ -968,6 +968,12 @@ class NewChatWidget extends Disposable implements IHistoryNavigationWidget {
 			return;
 		}
 
+		// Expand prompt/skill slash commands into a CLI-friendly reference
+		const expanded = this._slashCommandHandler?.tryExpandPromptSlashCommand(query);
+		if (expanded) {
+			query = expanded;
+		}
+
 		session.setQuery(query);
 		session.setAttachedContext(
 			this._contextAttachments.attachments.length > 0 ? [...this._contextAttachments.attachments] : undefined

src/vs/sessions/contrib/chat/browser/slashCommands.ts

@@ -21,6 +21,8 @@ import { inputPlaceholderForeground } from '../../../../platform/theme/common/co
 import { localize } from '../../../../nls.js';
 import { chatSlashCommandBackground, chatSlashCommandForeground } from '../../../../workbench/contrib/chat/common/widget/chatColors.js';
 import { AICustomizationManagementCommands, AICustomizationManagementSection } from '../../../../workbench/contrib/chat/browser/aiCustomization/aiCustomizationManagement.js';
+import { IAICustomizationWorkspaceService } from '../../../../workbench/contrib/chat/common/aiCustomizationWorkspaceService.js';
+import { IChatPromptSlashCommand, IPromptsService } from '../../../../workbench/contrib/chat/common/promptSyntax/service/promptsService.js';
 
 /**
  * Static command ID used by completion items to trigger immediate slash command execution,
@@ -57,30 +59,42 @@ export class SlashCommandHandler extends Disposable {
 	private static _slashDecosRegistered = false;
 
 	private readonly _slashCommands: ISessionsSlashCommandData[] = [];
+	private _cachedPromptCommands: readonly IChatPromptSlashCommand[] = [];
 
 	constructor(
 		private readonly _editor: CodeEditorWidget,
 		@ICommandService private readonly commandService: ICommandService,
 		@ICodeEditorService private readonly codeEditorService: ICodeEditorService,
 		@ILanguageFeaturesService private readonly languageFeaturesService: ILanguageFeaturesService,
 		@IThemeService private readonly themeService: IThemeService,
+		@IAICustomizationWorkspaceService private readonly aiCustomizationWorkspaceService: IAICustomizationWorkspaceService,
+		@IPromptsService private readonly promptsService: IPromptsService,
 	) {
 		super();
 		this._registerSlashCommands();
 		this._registerCompletions();
 		this._registerDecorations();
+		this._refreshPromptCommands();
+		this._register(this.promptsService.onDidChangeSlashCommands(() => this._refreshPromptCommands()));
 	}
 
 	clearInput(): void {
 		this._editor.getModel()?.setValue('');
 	}
 
+	private _refreshPromptCommands(): void {
+		this.aiCustomizationWorkspaceService.getFilteredPromptSlashCommands(CancellationToken.None).then(commands => {
+			this._cachedPromptCommands = commands;
+			this._updateDecorations();
+		}, () => { /* swallow errors from stale refresh */ });
+	}
+
 	/**
 	 * Attempts to parse and execute a slash command from the input.
 	 * Returns `true` if a command was handled.
 	 */
 	tryExecuteSlashCommand(query: string): boolean {
-		const match = query.match(/^\/(\w+)\s*(.*)/s);
+		const match = query.match(/^\/([\w\p{L}\d_\-\.:]+)\s*(.*)/su);
 		if (!match) {
 			return false;
 		}
@@ -95,6 +109,29 @@ export class SlashCommandHandler extends Disposable {
 		return true;
 	}
 
+	/**
+	 * If the query starts with a prompt/skill slash command (e.g. `/my-prompt args`),
+	 * expands it into a CLI-friendly markdown reference so the agent can locate the
+	 * file. Returns `undefined` when the query is not a prompt slash command.
+	 */
+	tryExpandPromptSlashCommand(query: string): string | undefined {
+		const match = query.match(/^\/([\w\p{L}\d_\-\.:]+)\s*(.*)/su);
+		if (!match) {
+			return undefined;
+		}
+
+		const commandName = match[1];
+		const promptCommand = this._cachedPromptCommands.find(c => c.name === commandName);
+		if (!promptCommand) {
+			return undefined;
+		}
+
+		const args = match[2]?.trim() ?? '';
+		const uri = promptCommand.promptPath.uri;
+		const expanded = `Use the prompt file located at [${promptCommand.name}](${uri.toString()}).`;
+		return args ? `${expanded} ${args}` : expanded;
+	}
+
 	private _registerSlashCommands(): void {
 		const openSection = (section: AICustomizationManagementSection) =>
 			() => this.commandService.executeCommand(AICustomizationManagementCommands.OpenEditor, section);
@@ -154,7 +191,7 @@ export class SlashCommandHandler extends Disposable {
 	private _updateDecorations(): void {
 		const model = this._editor.getModel();
 		const value = model?.getValue() ?? '';
-		const match = value.match(/^\/(\w+)\s?/);
+		const match = value.match(/^\/([\w\p{L}\d_\-\.:]+)\s?/u);
 
 		if (!match) {
 			this._editor.setDecorationsByType('sessions-chat', SlashCommandHandler._slashDecoType, []);
@@ -164,7 +201,8 @@ export class SlashCommandHandler extends Disposable {
 
 		const commandName = match[1];
 		const slashCommand = this._slashCommands.find(c => c.command === commandName);
-		if (!slashCommand) {
+		const promptCommand = this._cachedPromptCommands.find(c => c.name === commandName);
+		if (!slashCommand && !promptCommand) {
 			this._editor.setDecorationsByType('sessions-chat', SlashCommandHandler._slashDecoType, []);
 			this._editor.setDecorationsByType('sessions-chat', SlashCommandHandler._slashPlaceholderDecoType, []);
 			return;
@@ -179,13 +217,14 @@ export class SlashCommandHandler extends Disposable {
 
 		// Show the command description as a placeholder after the command
 		const restOfInput = value.slice(match[0].length).trim();
-		if (!restOfInput && slashCommand.detail) {
+		const detail = slashCommand?.detail ?? promptCommand?.description;
+		if (!restOfInput && detail) {
 			const placeholderCol = match[0].length + 1;
 			const placeholderDeco: IDecorationOptions[] = [{
 				range: { startLineNumber: 1, startColumn: placeholderCol, endLineNumber: 1, endColumn: model!.getLineMaxColumn(1) },
 				renderOptions: {
 					after: {
-						contentText: slashCommand.detail,
+						contentText: detail,
 						color: this._getPlaceholderColor(),
 					}
 				}
@@ -238,6 +277,44 @@ export class SlashCommandHandler extends Disposable {
 				};
 			}
 		}));
+
+		// Dynamic completions for individual prompt/skill files (filtered to match
+		// what the sessions customizations view shows).
+		this._register(this.languageFeaturesService.completionProvider.register({ scheme: uri.scheme, hasAccessToAllModels: true }, {
+			_debugDisplayName: 'sessionsPromptSlashCommands',
+			triggerCharacters: ['/'],
+			provideCompletionItems: async (model: ITextModel, position: Position, _context: CompletionContext, token: CancellationToken) => {
+				const range = this._computeCompletionRanges(model, position, /\/[\p{L}0-9_.:-]*/gu);
+				if (!range) {
+					return null;
+				}
+
+				const textBefore = model.getValueInRange(new Range(1, 1, range.replace.startLineNumber, range.replace.startColumn));
+				if (textBefore.trim() !== '') {
+					return null;
+				}
+
+				const promptCommands = await this.aiCustomizationWorkspaceService.getFilteredPromptSlashCommands(token);
+				const userInvocable = promptCommands.filter(c => c.parsedPromptFile?.header?.userInvocable !== false);
+				if (userInvocable.length === 0) {
+					return null;
+				}
+
+				return {
+					suggestions: userInvocable.map((c, i): CompletionItem => {
+						const label = `/${c.name}`;
+						return {
+							label: { label, description: c.description },
+							insertText: `${label} `,
+							documentation: c.description,
+							range,
+							sortText: 'b'.repeat(i + 1),
+							kind: CompletionItemKind.Text,
+						};
+					})
+				};
+			}
+		}));
 	}
 
 	private _computeCompletionRanges(model: ITextModel, position: Position, reg: RegExp): { insert: Range; replace: Range } | undefined {

src/vs/workbench/contrib/chat/browser/aiCustomization/aiCustomizationWorkspaceService.ts

@@ -5,10 +5,11 @@
 
 import { constObservable, derived, IObservable, observableFromEventOpts } from '../../../../../base/common/observable.js';
 import { URI } from '../../../../../base/common/uri.js';
+import { CancellationToken } from '../../../../../base/common/cancellation.js';
 import { IWorkspaceContextService } from '../../../../../platform/workspace/common/workspace.js';
 import { IAICustomizationWorkspaceService, AICustomizationManagementSection, IStorageSourceFilter } from '../../common/aiCustomizationWorkspaceService.js';
 import { InstantiationType, registerSingleton } from '../../../../../platform/instantiation/common/extensions.js';
-import { PromptsStorage } from '../../common/promptSyntax/service/promptsService.js';
+import { IChatPromptSlashCommand, IPromptsService, PromptsStorage } from '../../common/promptSyntax/service/promptsService.js';
 import { ICommandService } from '../../../../../platform/commands/common/commands.js';
 import { PromptsType } from '../../common/promptSyntax/promptTypes.js';
 import {
@@ -27,6 +28,7 @@ class AICustomizationWorkspaceService implements IAICustomizationWorkspaceServic
 	constructor(
 		@IWorkspaceContextService private readonly workspaceContextService: IWorkspaceContextService,
 		@ICommandService private readonly commandService: ICommandService,
+		@IPromptsService private readonly promptsService: IPromptsService,
 	) {
 		const workspaceFolders = observableFromEventOpts(
 			{ owner: this },
@@ -84,6 +86,10 @@ class AICustomizationWorkspaceService implements IAICustomizationWorkspaceServic
 			await this.commandService.executeCommand(commandId);
 		}
 	}
+
+	async getFilteredPromptSlashCommands(token: CancellationToken): Promise<readonly IChatPromptSlashCommand[]> {
+		return this.promptsService.getPromptSlashCommands(token);
+	}
 }
 
 registerSingleton(IAICustomizationWorkspaceService, AICustomizationWorkspaceService, InstantiationType.Delayed);

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

@@ -3,12 +3,13 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import { CancellationToken } from '../../../../base/common/cancellation.js';
 import { IObservable } from '../../../../base/common/observable.js';
 import { URI } from '../../../../base/common/uri.js';
 import { isEqualOrParent } from '../../../../base/common/resources.js';
 import { createDecorator } from '../../../../platform/instantiation/common/instantiation.js';
 import { PromptsType } from './promptSyntax/promptTypes.js';
-import { PromptsStorage } from './promptSyntax/service/promptsService.js';
+import { IChatPromptSlashCommand, PromptsStorage } from './promptSyntax/service/promptsService.js';
 
 export const IAICustomizationWorkspaceService = createDecorator<IAICustomizationWorkspaceService>('aiCustomizationWorkspaceService');
 
@@ -121,4 +122,11 @@ export interface IAICustomizationWorkspaceService {
 	 * session-derived (or workspace-derived) root.
 	 */
 	clearOverrideProjectRoot(): void;
+
+	/**
+	 * Returns prompt/skill slash commands filtered through the workspace
+	 * service's storage source policy, ensuring the results match the
+	 * customizations visible in the AI Customization views.
+	 */
+	getFilteredPromptSlashCommands(token: CancellationToken): Promise<readonly IChatPromptSlashCommand[]>;
 }