Add support for GH Custom Agents

src/vs/workbench/api/browser/mainThreadChatAgents2.ts

@@ -26,6 +26,7 @@ import { IUriIdentityService } from '../../../platform/uriIdentity/common/uriIde
 import { IChatWidgetService } from '../../contrib/chat/browser/chat.js';
 import { AddDynamicVariableAction, IAddDynamicVariableContext } from '../../contrib/chat/browser/contrib/chatDynamicVariables.js';
 import { IChatAgentHistoryEntry, IChatAgentImplementation, IChatAgentRequest, IChatAgentService } from '../../contrib/chat/common/chatAgents.js';
+import { ICustomAgentQueryOptions, IPromptsService } from '../../contrib/chat/common/promptSyntax/service/promptsService.js';
 import { IChatEditingService, IChatRelatedFileProviderMetadata } from '../../contrib/chat/common/chatEditingService.js';
 import { IChatModel } from '../../contrib/chat/common/chatModel.js';
 import { ChatRequestAgentPart } from '../../contrib/chat/common/chatParserTypes.js';
@@ -96,6 +97,9 @@ export class MainThreadChatAgents2 extends Disposable implements MainThreadChatA
 
 	private readonly _chatRelatedFilesProviders = this._register(new DisposableMap<number, IDisposable>());
 
+	private readonly _customAgentsProviders = this._register(new DisposableMap<number, IDisposable>());
+	private readonly _customAgentsProviderEmitters = this._register(new DisposableMap<number, Emitter<void>>());
+
 	private readonly _pendingProgress = new Map<string, { progress: (parts: IChatProgress[]) => void; chatSession: IChatModel | undefined }>();
 	private readonly _proxy: ExtHostChatAgentsShape2;
 
@@ -115,6 +119,7 @@ export class MainThreadChatAgents2 extends Disposable implements MainThreadChatA
 		@ILogService private readonly _logService: ILogService,
 		@IExtensionService private readonly _extensionService: IExtensionService,
 		@IUriIdentityService private readonly _uriIdentityService: IUriIdentityService,
+		@IPromptsService private readonly _promptsService: IPromptsService,
 	) {
 		super();
 		this._proxy = extHostContext.getProxy(ExtHostContext.ExtHostChatAgents2);
@@ -427,6 +432,46 @@ export class MainThreadChatAgents2 extends Disposable implements MainThreadChatA
 	$unregisterRelatedFilesProvider(handle: number): void {
 		this._chatRelatedFilesProviders.deleteAndDispose(handle);
 	}
+
+	async $registerCustomAgentsProvider(handle: number, extensionId: ExtensionIdentifier): Promise<void> {
+		const extension = await this._extensionService.getExtension(extensionId.value);
+		if (!extension) {
+			this._logService.error(`[MainThreadChatAgents2] Could not find extension for CustomAgentsProvider: ${extensionId.value}`);
+			return;
+		}
+
+		const emitter = new Emitter<void>();
+		this._customAgentsProviderEmitters.set(handle, emitter);
+
+		const disposable = this._promptsService.registerCustomAgentsProvider(extension, {
+			onDidChangeCustomAgents: emitter.event,
+			provideCustomAgents: async (options: ICustomAgentQueryOptions, token: CancellationToken) => {
+				const agents = await this._proxy.$provideCustomAgents(handle, options, token);
+				if (!agents) {
+					return undefined;
+				}
+				// Convert UriComponents to URI
+				return agents.map(agent => ({
+					...agent,
+					uri: URI.revive(agent.uri)
+				}));
+			}
+		});
+
+		this._customAgentsProviders.set(handle, disposable);
+	}
+
+	$unregisterCustomAgentsProvider(handle: number): void {
+		this._customAgentsProviders.deleteAndDispose(handle);
+		this._customAgentsProviderEmitters.deleteAndDispose(handle);
+	}
+
+	$onDidChangeCustomAgents(handle: number): void {
+		const emitter = this._customAgentsProviderEmitters.get(handle);
+		if (emitter) {
+			emitter.fire();
+		}
+	}
 }
 
 

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -1541,6 +1541,10 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				checkProposedApiEnabled(extension, 'chatContextProvider');
 				return extHostChatContext.registerChatContextProvider(selector ? checkSelector(selector) : undefined, `${extension.id}-${id}`, provider);
 			},
+			registerCustomAgentsProvider(provider: vscode.CustomAgentsProvider): vscode.Disposable {
+				checkProposedApiEnabled(extension, 'chatParticipantPrivate');
+				return extHostChatAgents2.registerCustomAgentsProvider(extension, provider);
+			},
 		};
 
 		// namespace: lm
@@ -1942,7 +1946,8 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			McpStdioServerDefinition: extHostTypes.McpStdioServerDefinition,
 			McpStdioServerDefinition2: extHostTypes.McpStdioServerDefinition,
 			McpToolAvailability: extHostTypes.McpToolAvailability,
-			SettingsSearchResultKind: extHostTypes.SettingsSearchResultKind
+			SettingsSearchResultKind: extHostTypes.SettingsSearchResultKind,
+			CustomAgentTarget: extHostTypes.CustomAgentTarget,
 		};
 	};
 }

src/vs/workbench/api/common/extHost.protocol.ts

@@ -65,6 +65,7 @@ import { IChatRequestVariableValue } from '../../contrib/chat/common/chatVariabl
 import { ChatAgentLocation } from '../../contrib/chat/common/constants.js';
 import { IChatMessage, IChatResponsePart, ILanguageModelChatMetadataAndIdentifier, ILanguageModelChatSelector } from '../../contrib/chat/common/languageModels.js';
 import { IPreparedToolInvocation, IToolInvocation, IToolInvocationPreparationContext, IToolProgressStep, IToolResult, ToolDataSource } from '../../contrib/chat/common/languageModelToolsService.js';
+import { ICustomAgentQueryOptions, IExternalCustomAgent } from '../../contrib/chat/common/promptSyntax/service/promptsService.js';
 import { DebugConfigurationProviderTriggerKind, IAdapterDescriptor, IConfig, IDebugSessionReplMode, IDebugTestRunReference, IDebugVisualization, IDebugVisualizationContext, IDebugVisualizationTreeItem, MainThreadDebugVisualization } from '../../contrib/debug/common/debug.js';
 import { McpCollectionDefinition, McpConnectionState, McpServerDefinition, McpServerLaunch } from '../../contrib/mcp/common/mcpTypes.js';
 import * as notebookCommon from '../../contrib/notebook/common/notebookCommon.js';
@@ -1393,6 +1394,9 @@ export interface MainThreadChatAgentsShape2 extends IChatAgentProgressShape, IDi
 	$unregisterChatParticipantDetectionProvider(handle: number): void;
 	$registerRelatedFilesProvider(handle: number, metadata: IChatRelatedFilesProviderMetadata): void;
 	$unregisterRelatedFilesProvider(handle: number): void;
+	$registerCustomAgentsProvider(handle: number, extension: ExtensionIdentifier): void;
+	$unregisterCustomAgentsProvider(handle: number): void;
+	$onDidChangeCustomAgents(handle: number): void;
 	$registerAgentCompletionsProvider(handle: number, id: string, triggerCharacters: string[]): void;
 	$unregisterAgentCompletionsProvider(handle: number, id: string): void;
 	$updateAgent(handle: number, metadataUpdate: IExtensionChatAgentMetadata): void;
@@ -1457,6 +1461,7 @@ export interface ExtHostChatAgentsShape2 {
 	$releaseSession(sessionId: string): void;
 	$detectChatParticipant(handle: number, request: Dto<IChatAgentRequest>, context: { history: IChatAgentHistoryEntryDto[] }, options: { participants: IChatParticipantMetadata[]; location: ChatAgentLocation }, token: CancellationToken): Promise<IChatParticipantDetectionResult | null | undefined>;
 	$provideRelatedFiles(handle: number, request: Dto<IChatRequestDraft>, token: CancellationToken): Promise<Dto<IChatRelatedFile>[] | undefined>;
+	$provideCustomAgents(handle: number, options: ICustomAgentQueryOptions, token: CancellationToken): Promise<Dto<IExternalCustomAgent>[] | undefined>;
 	$setRequestTools(requestId: string, tools: UserSelectedTools): void;
 }
 export interface IChatParticipantMetadata {

src/vs/workbench/api/common/extHostChatAgents2.ts

@@ -34,6 +34,7 @@ import { ExtHostLanguageModels } from './extHostLanguageModels.js';
 import { ExtHostLanguageModelTools } from './extHostLanguageModelTools.js';
 import * as typeConvert from './extHostTypeConverters.js';
 import * as extHostTypes from './extHostTypes.js';
+import { ICustomAgentQueryOptions, IExternalCustomAgent } from '../../contrib/chat/common/promptSyntax/service/promptsService.js';
 
 export class ChatAgentResponseStream {
 
@@ -394,6 +395,9 @@ export class ExtHostChatAgents2 extends Disposable implements ExtHostChatAgentsS
 	private static _relatedFilesProviderIdPool = 0;
 	private readonly _relatedFilesProviders = new Map<number, ExtHostRelatedFilesProvider>();
 
+	private static _customAgentsProviderIdPool = 0;
+	private readonly _customAgentsProviders = new Map<number, { extension: IExtensionDescription; provider: vscode.CustomAgentsProvider }>();
+
 	private readonly _sessionDisposables: DisposableMap<string, DisposableStore> = this._register(new DisposableMap());
 	private readonly _completionDisposables: DisposableMap<number, DisposableStore> = this._register(new DisposableMap());
 
@@ -471,6 +475,28 @@ export class ExtHostChatAgents2 extends Disposable implements ExtHostChatAgentsS
 		});
 	}
 
+	registerCustomAgentsProvider(extension: IExtensionDescription, provider: vscode.CustomAgentsProvider): vscode.Disposable {
+		const handle = ExtHostChatAgents2._customAgentsProviderIdPool++;
+		this._customAgentsProviders.set(handle, { extension, provider });
+		this._proxy.$registerCustomAgentsProvider(handle, extension.identifier);
+
+		const disposables = new DisposableStore();
+
+		// Listen to provider change events and notify main thread
+		if (provider.onDidChangeCustomAgents) {
+			disposables.add(provider.onDidChangeCustomAgents(() => {
+				this._proxy.$onDidChangeCustomAgents(handle);
+			}));
+		}
+
+		disposables.add(toDisposable(() => {
+			this._customAgentsProviders.delete(handle);
+			this._proxy.$unregisterCustomAgentsProvider(handle);
+		}));
+
+		return disposables;
+	}
+
 	async $provideRelatedFiles(handle: number, request: IChatRequestDraft, token: CancellationToken): Promise<Dto<IChatRelatedFile>[] | undefined> {
 		const provider = this._relatedFilesProviders.get(handle);
 		if (!provider) {
@@ -481,6 +507,15 @@ export class ExtHostChatAgents2 extends Disposable implements ExtHostChatAgentsS
 		return await provider.provider.provideRelatedFiles(extRequestDraft, token) ?? undefined;
 	}
 
+	async $provideCustomAgents(handle: number, options: ICustomAgentQueryOptions, token: CancellationToken): Promise<IExternalCustomAgent[] | undefined> {
+		const providerData = this._customAgentsProviders.get(handle);
+		if (!providerData) {
+			return Promise.resolve(undefined);
+		}
+
+		return await providerData.provider.provideCustomAgents(options, token) ?? undefined;
+	}
+
 	async $detectChatParticipant(handle: number, requestDto: Dto<IChatAgentRequest>, context: { history: IChatAgentHistoryEntryDto[] }, options: { location: ChatAgentLocation; participants?: vscode.ChatParticipantMetadata[] }, token: CancellationToken): Promise<vscode.ChatParticipantDetectionResult | null | undefined> {
 		const detector = this._participantDetectionProviders.get(handle);
 		if (!detector) {

src/vs/workbench/api/common/extHostTypes.ts

@@ -3489,6 +3489,11 @@ export enum ChatErrorLevel {
 	Error = 2
 }
 
+export enum CustomAgentTarget {
+	GitHubCopilot = 'github-copilot',
+	VSCode = 'vscode',
+}
+
 export class LanguageModelChatMessage implements vscode.LanguageModelChatMessage {
 
 	static User(content: string | (LanguageModelTextPart | LanguageModelToolResultPart | LanguageModelToolCallPart | LanguageModelDataPart)[], name?: string): LanguageModelChatMessage {

src/vs/workbench/contrib/chat/browser/modelPicker/modePickerActionItem.ts

@@ -27,7 +27,7 @@ import { IProductService } from '../../../../../platform/product/common/productS
 import { IChatAgentService } from '../../common/chatAgents.js';
 import { ChatMode, IChatMode, IChatModeService } from '../../common/chatModes.js';
 import { ChatAgentLocation, ChatConfiguration, ChatModeKind } from '../../common/constants.js';
-import { PromptsStorage } from '../../common/promptSyntax/service/promptsService.js';
+import { ExtensionAgentSourceType, PromptsStorage } from '../../common/promptSyntax/service/promptsService.js';
 import { getOpenChatActionIdForMode } from '../actions/chatActions.js';
 import { IToggleChatModeArgs, ToggleAgentModeActionId } from '../actions/chatExecuteActions.js';
 
@@ -104,7 +104,7 @@ export class ModePickerActionItem extends ActionWidgetDropdownActionViewItem {
 				const otherBuiltinModes = modes.builtin.filter(mode => mode.id !== ChatMode.Agent.id);
 				const customModes = groupBy(
 					modes.custom,
-					mode => mode.source?.storage === PromptsStorage.extension && mode.source.extensionId.value === productService.defaultChatAgent?.chatExtensionId ?
+					mode => mode.source?.storage === PromptsStorage.extension && mode.source.extensionId.value === productService.defaultChatAgent?.chatExtensionId && mode.source.type === ExtensionAgentSourceType.contribution ?
 						'builtin' : 'custom');
 
 				const customBuiltinModeActions = customModes.builtin?.map(mode => {

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

@@ -20,7 +20,7 @@ import { IChatAgentService } from './chatAgents.js';
 import { ChatContextKeys } from './chatContextKeys.js';
 import { ChatConfiguration, ChatModeKind } from './constants.js';
 import { IHandOff } from './promptSyntax/promptFileParser.js';
-import { IAgentSource, ICustomAgent, IPromptsService, PromptsStorage } from './promptSyntax/service/promptsService.js';
+import { ExtensionAgentSourceType, IAgentSource, ICustomAgent, IPromptsService, PromptsStorage } from './promptSyntax/service/promptsService.js';
 
 export const IChatModeService = createDecorator<IChatModeService>('chatModeService');
 export interface IChatModeService {
@@ -419,7 +419,7 @@ export class CustomChatMode implements IChatMode {
 }
 
 type IChatModeSourceData =
-	| { readonly storage: PromptsStorage.extension; readonly extensionId: string }
+	| { readonly storage: PromptsStorage.extension; readonly extensionId: string; type?: ExtensionAgentSourceType }
 	| { readonly storage: PromptsStorage.local | PromptsStorage.user };
 
 function isChatModeSourceData(value: unknown): value is IChatModeSourceData {
@@ -438,7 +438,7 @@ function serializeChatModeSource(source: IAgentSource | undefined): IChatModeSou
 		return undefined;
 	}
 	if (source.storage === PromptsStorage.extension) {
-		return { storage: PromptsStorage.extension, extensionId: source.extensionId.value };
+		return { storage: PromptsStorage.extension, extensionId: source.extensionId.value, type: source.type };
 	}
 	return { storage: source.storage };
 }
@@ -448,7 +448,7 @@ function reviveChatModeSource(data: IChatModeSourceData | undefined): IAgentSour
 		return undefined;
 	}
 	if (data.storage === PromptsStorage.extension) {
-		return { storage: PromptsStorage.extension, extensionId: new ExtensionIdentifier(data.extensionId) };
+		return { storage: PromptsStorage.extension, extensionId: new ExtensionIdentifier(data.extensionId), type: data.type ?? ExtensionAgentSourceType.contribution };
 	}
 	return { storage: data.storage };
 }

src/vs/workbench/contrib/chat/common/promptSyntax/service/promptsService.ts

@@ -15,6 +15,44 @@ import { PromptsType } from '../promptTypes.js';
 import { IHandOff, ParsedPromptFile } from '../promptFileParser.js';
 import { ResourceSet } from '../../../../../../base/common/map.js';
 
+/**
+ * Target environment for custom agents.
+ */
+export enum CustomAgentTarget {
+	GitHubCopilot = 'github-copilot',
+	VSCode = 'vscode',
+}
+
+/**
+ * Options for querying custom agents.
+ */
+export interface ICustomAgentQueryOptions {
+	/**
+	 * Filter agents by target environment.
+	 */
+	readonly target?: CustomAgentTarget;
+}
+
+/**
+ * Represents a custom agent resource from an external provider.
+ */
+export interface IExternalCustomAgent {
+	/**
+	 * The unique identifier/name of the custom agent resource.
+	 */
+	readonly name: string;
+
+	/**
+	 * A description of what the custom agent resource does.
+	 */
+	readonly description: string;
+
+	/**
+	 * The URI to the agent or prompt resource file.
+	 */
+	readonly uri: URI;
+}
+
 /**
  * Provides prompt services.
  */
@@ -29,6 +67,14 @@ export enum PromptsStorage {
 	extension = 'extension'
 }
 
+/**
+ * The type of source for extension agents.
+ */
+export enum ExtensionAgentSourceType {
+	contribution = 'contribution',
+	provider = 'provider',
+}
+
 /**
  * Represents a prompt path with its type.
  * This is used for both prompt files and prompt source folders.
@@ -67,6 +113,7 @@ export interface IExtensionPromptPath extends IPromptPathBase {
 	readonly extension: IExtensionDescription;
 	readonly name: string;
 	readonly description: string;
+	readonly source: ExtensionAgentSourceType;
 }
 export interface ILocalPromptPath extends IPromptPathBase {
 	readonly storage: PromptsStorage.local;
@@ -78,6 +125,7 @@ export interface IUserPromptPath extends IPromptPathBase {
 export type IAgentSource = {
 	readonly storage: PromptsStorage.extension;
 	readonly extensionId: ExtensionIdentifier;
+	readonly type: ExtensionAgentSourceType;
 } | {
 	readonly storage: PromptsStorage.local | PromptsStorage.user;
 };
@@ -270,6 +318,18 @@ export interface IPromptsService extends IDisposable {
 	 */
 	setDisabledPromptFiles(type: PromptsType, uris: ResourceSet): void;
 
+	/**
+	 * Registers a CustomAgentsProvider that can provide custom agents for repositories.
+	 * This is part of the proposed API and requires the chatParticipantPrivate proposal.
+	 * @param extension The extension registering the provider.
+	 * @param provider The provider implementation with optional change event.
+	 * @returns A disposable that unregisters the provider when disposed.
+	 */
+	registerCustomAgentsProvider(extension: IExtensionDescription, provider: {
+		onDidChangeCustomAgents?: Event<void>;
+		provideCustomAgents: (options: ICustomAgentQueryOptions, token: CancellationToken) => Promise<IExternalCustomAgent[] | undefined>;
+	}): IDisposable;
+
 	/**
 	 * Gets list of claude skills files.
 	 */