Add support for custom chat agents in the API (#298227)

* Add support for custom chat agents in the API

- Introduced `chatCustomAgents` proposal in extensions API.
- Implemented methods to handle custom agents in `MainThreadChatAgents2`.
- Added `ICustomAgentDto` interface and related functionality in extHost.
- Created new type definitions for custom agents in `vscode.proposed.chatCustomAgents.d.ts`.

* Filter custom agents by visibility before pushing to the proxy

* Refactor onDidChangeCustomAgents to use direct event listener

* Update custom agent tools property to allow undefined values

* Add chatCustomAgents to enabledApiProposals in package.json

* update

* update

* support skills

* support instructions

* update

* update

---------

Co-authored-by: Martin Aeschlimann <martinae@microsoft.com>

extensions/vscode-api-tests/package.json

@@ -9,6 +9,7 @@
     "authSession",
     "environmentPower",
     "chatParticipantPrivate",
+    "chatPromptFiles",
     "chatProvider",
     "contribStatusBarItems",
     "contribViewsRemote",

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

@@ -40,7 +40,7 @@ import { ILanguageModelToolsService } from '../../contrib/chat/common/tools/lang
 import { IExtHostContext, extHostNamedCustomer } from '../../services/extensions/common/extHostCustomers.js';
 import { IExtensionService } from '../../services/extensions/common/extensions.js';
 import { Dto } from '../../services/extensions/common/proxyIdentifier.js';
-import { ExtHostChatAgentsShape2, ExtHostContext, IChatNotebookEditDto, IChatParticipantMetadata, IChatProgressDto, IChatSessionContextDto, IDynamicChatAgentProps, IExtensionChatAgentMetadata, MainContext, MainThreadChatAgentsShape2 } from '../common/extHost.protocol.js';
+import { ExtHostChatAgentsShape2, ExtHostContext, IChatNotebookEditDto, IChatParticipantMetadata, IChatProgressDto, IChatSessionContextDto, ICustomAgentDto, IDynamicChatAgentProps, IExtensionChatAgentMetadata, IInstructionDto, ISkillDto, MainContext, MainThreadChatAgentsShape2 } from '../common/extHost.protocol.js';
 import { NotebookDto } from './mainThreadNotebookDto.js';
 
 interface AgentData {
@@ -153,6 +153,24 @@ export class MainThreadChatAgents2 extends Disposable implements MainThreadChatA
 
 		// Push the initial active session if there is already a focused widget
 		this._acceptActiveChatSession(this._chatWidgetService.lastFocusedWidget);
+
+		// Push custom agents to ext host
+		void this._pushCustomAgents();
+		this._register(this._promptsService.onDidChangeCustomAgents(() => {
+			void this._pushCustomAgents();
+		}));
+
+		// Push instructions to ext host
+		void this._pushInstructions();
+		this._register(this._promptsService.onDidChangeInstructions(() => {
+			void this._pushInstructions();
+		}));
+
+		// Push skills to ext host
+		void this._pushSkills();
+		this._register(this._promptsService.onDidChangeSkills(() => {
+			void this._pushSkills();
+		}));
 	}
 
 	private _acceptActiveChatSession(widget: IChatWidget | undefined): void {
@@ -161,6 +179,36 @@ export class MainThreadChatAgents2 extends Disposable implements MainThreadChatA
 		this._proxy.$acceptActiveChatSession(isLocal ? sessionResource : undefined);
 	}
 
+	private async _pushCustomAgents(): Promise<void> {
+		try {
+			const customAgents = await this._promptsService.getCustomAgents(CancellationToken.None);
+			const dtos: ICustomAgentDto[] = customAgents.map(agent => ({ uri: agent.uri }));
+			this._proxy.$acceptCustomAgents(dtos);
+		} catch (error) {
+			this._logService.error('[chat] Failed to push custom agents to extension host', error);
+		}
+	}
+
+	private async _pushInstructions(): Promise<void> {
+		try {
+			const instructions = await this._promptsService.getInstructionFiles(CancellationToken.None);
+			const dtos: IInstructionDto[] = instructions.map(instruction => ({ uri: instruction.uri }));
+			this._proxy.$acceptInstructions(dtos);
+		} catch (error) {
+			this._logService.error('[chat] Failed to push instructions to extension host', error);
+		}
+	}
+
+	private async _pushSkills(): Promise<void> {
+		try {
+			const skills = await this._promptsService.findAgentSkills(CancellationToken.None) ?? [];
+			const dtos: ISkillDto[] = skills.map(skill => ({ uri: skill.uri }));
+			this._proxy.$acceptSkills(dtos);
+		} catch (error) {
+			this._logService.error('[chat] Failed to push skills to extension host', error);
+		}
+	}
+
 	$unregisterAgent(handle: number): void {
 		this._agents.deleteAndDispose(handle);
 	}

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

@@ -1677,6 +1677,30 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				checkProposedApiEnabled(extension, 'chatDebug');
 				return extHostChatDebug.registerChatDebugLogProvider(provider);
 			},
+			get customAgents() {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.customAgents as readonly vscode.ChatResource[];
+			},
+			onDidChangeCustomAgents: (listener, thisArgs?, disposables?) => {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.onDidChangeCustomAgents(listener, thisArgs, disposables);
+			},
+			get instructions() {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.instructions as readonly vscode.ChatResource[];
+			},
+			onDidChangeInstructions: (listener, thisArgs?, disposables?) => {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.onDidChangeInstructions(listener, thisArgs, disposables);
+			},
+			get skills() {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.skills as readonly vscode.ChatResource[];
+			},
+			onDidChangeSkills: (listener, thisArgs?, disposables?) => {
+				checkProposedApiEnabled(extension, 'chatPromptFiles');
+				return extHostChatAgents2.onDidChangeSkills(listener, thisArgs, disposables);
+			},
 		};
 
 		// namespace: lm

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

@@ -1614,6 +1614,21 @@ export interface ExtHostChatAgentsShape2 {
 	$setRequestTools(requestId: string, tools: UserSelectedTools): void;
 	$setYieldRequested(requestId: string, value: boolean): void;
 	$acceptActiveChatSession(sessionResource: UriComponents | undefined): void;
+	$acceptCustomAgents(agents: ICustomAgentDto[]): void;
+	$acceptInstructions(instructions: IInstructionDto[]): void;
+	$acceptSkills(skills: ISkillDto[]): void;
+}
+
+export interface ICustomAgentDto {
+	uri: UriComponents;
+}
+
+export interface IInstructionDto {
+	uri: UriComponents;
+}
+
+export interface ISkillDto {
+	uri: UriComponents;
 }
 export interface IChatParticipantMetadata {
 	participant: string;

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

@@ -27,7 +27,7 @@ import { LocalChatSessionUri } from '../../contrib/chat/common/model/chatUri.js'
 import { ChatAgentLocation } from '../../contrib/chat/common/constants.js';
 import { checkProposedApiEnabled, isProposedApiEnabled } from '../../services/extensions/common/extensions.js';
 import { Dto } from '../../services/extensions/common/proxyIdentifier.js';
-import { ExtHostChatAgentsShape2, IChatAgentCompletionItem, IChatAgentHistoryEntryDto, IChatAgentProgressShape, IChatProgressDto, IChatSessionContextDto, IExtensionChatAgentMetadata, IMainContext, MainContext, MainThreadChatAgentsShape2 } from './extHost.protocol.js';
+import { ExtHostChatAgentsShape2, IChatAgentCompletionItem, IChatAgentHistoryEntryDto, IChatAgentProgressShape, IChatProgressDto, IChatSessionContextDto, ICustomAgentDto, IExtensionChatAgentMetadata, IInstructionDto, IMainContext, ISkillDto, MainContext, MainThreadChatAgentsShape2 } from './extHost.protocol.js';
 import { CommandsConverter, ExtHostCommands } from './extHostCommands.js';
 import { ExtHostDiagnostics } from './extHostDiagnostics.js';
 import { ExtHostDocuments } from './extHostDocuments.js';
@@ -487,6 +487,17 @@ export class ExtHostChatAgents2 extends Disposable implements ExtHostChatAgentsS
 	private readonly _onDidDisposeChatSession = this._register(new Emitter<string>());
 	readonly onDidDisposeChatSession = this._onDidDisposeChatSession.event;
 
+	private readonly _onDidChangeCustomAgents = this._register(new Emitter<void>());
+	readonly onDidChangeCustomAgents = this._onDidChangeCustomAgents.event;
+	private readonly _onDidChangeInstructions = this._register(new Emitter<void>());
+	readonly onDidChangeInstructions = this._onDidChangeInstructions.event;
+	private readonly _onDidChangeSkills = this._register(new Emitter<void>());
+	readonly onDidChangeSkills = this._onDidChangeSkills.event;
+
+	private _customAgents: vscode.ChatResource[] = [];
+	private _instructions: vscode.ChatResource[] = [];
+	private _skills: vscode.ChatResource[] = [];
+
 	private _activeChatPanelSessionResource: URI | undefined;
 
 	private readonly _onDidChangeActiveChatPanelSessionResource = this._register(new Emitter<URI | undefined>());
@@ -496,6 +507,33 @@ export class ExtHostChatAgents2 extends Disposable implements ExtHostChatAgentsS
 		return this._activeChatPanelSessionResource;
 	}
 
+	get customAgents(): readonly vscode.ChatResource[] {
+		return this._customAgents;
+	}
+
+	get instructions(): readonly vscode.ChatResource[] {
+		return this._instructions;
+	}
+
+	get skills(): readonly vscode.ChatResource[] {
+		return this._skills;
+	}
+
+	$acceptCustomAgents(agents: ICustomAgentDto[]): void {
+		this._customAgents = agents.map(a => Object.freeze({ uri: URI.revive(a.uri) }));
+		this._onDidChangeCustomAgents.fire();
+	}
+
+	$acceptInstructions(instructions: IInstructionDto[]): void {
+		this._instructions = instructions.map(i => Object.freeze({ uri: URI.revive(i.uri) }));
+		this._onDidChangeInstructions.fire();
+	}
+
+	$acceptSkills(skills: ISkillDto[]): void {
+		this._skills = skills.map(s => Object.freeze({ uri: URI.revive(s.uri) }));
+		this._onDidChangeSkills.fire();
+	}
+
 	constructor(
 		mainContext: IMainContext,
 		private readonly _logService: ILogService,

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

@@ -417,6 +417,11 @@ export interface IPromptsService extends IDisposable {
 	 */
 	readonly onDidChangeCustomAgents: Event<void>;
 
+	/**
+	 * Event that is triggered when the list of instruction files changes.
+	 */
+	readonly onDidChangeInstructions: Event<void>;
+
 	/**
 	 * Finds all available custom agents
 	 * @param sessionResource Optional session resource to scope debug logging to a specific session.
@@ -483,6 +488,11 @@ export interface IPromptsService extends IDisposable {
 	 */
 	findAgentSkills(token: CancellationToken, sessionResource?: URI): Promise<IAgentSkill[] | undefined>;
 
+	/**
+	 * Event that is triggered when the list of skills changes.
+	 */
+	readonly onDidChangeSkills: Event<void>;
+
 	/**
 	 * Gets detailed discovery information for a prompt type.
 	 * This includes all files found and their load/skip status with reasons.

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

@@ -152,6 +152,7 @@ export class PromptsService extends Disposable implements IPromptsService {
 	private readonly _contributedWhenKeys = new Set<string>();
 	private readonly _contributedWhenClauses = new Map<string, string>();
 	private readonly _onDidContributedWhenChange = this._register(new Emitter<void>());
+	private readonly _onDidChangeInstructions = this._register(new Emitter<void>());
 	private readonly _onDidPluginPromptFilesChange = this._register(new Emitter<void>());
 	private readonly _onDidPluginHooksChange = this._register(new Emitter<void>());
 	private _pluginPromptFilesByType = new Map<PromptsType, readonly IPluginPromptPath[]>();
@@ -417,6 +418,7 @@ export class PromptsService extends Disposable implements IPromptsService {
 			this.cachedCustomAgents.refresh();
 		} else if (type === PromptsType.instructions) {
 			this.cachedFileLocations[PromptsType.instructions] = undefined;
+			this._onDidChangeInstructions.fire();
 		} else if (type === PromptsType.prompt) {
 			this.cachedFileLocations[PromptsType.prompt] = undefined;
 			this.cachedSlashCommands.refresh();
@@ -644,6 +646,14 @@ export class PromptsService extends Disposable implements IPromptsService {
 		return this.cachedCustomAgents.onDidChange;
 	}
 
+	public get onDidChangeInstructions(): Event<void> {
+		return Event.any(
+			this.getFileLocatorEvent(PromptsType.instructions),
+			this._onDidContributedWhenChange.event,
+			this._onDidChangeInstructions.event,
+		);
+	}
+
 	public async getCustomAgents(token: CancellationToken, sessionResource?: URI): Promise<readonly ICustomAgent[]> {
 		const sw = StopWatch.create();
 		const result = await this.cachedCustomAgents.get(token);

src/vs/workbench/contrib/chat/test/common/promptSyntax/service/mockPromptsService.ts

@@ -18,8 +18,8 @@ export class MockPromptsService implements IPromptsService {
 
 	_serviceBrand: undefined;
 
-	private readonly _onDidChangeCustomChatModes = new Emitter<void>();
-	readonly onDidChangeCustomAgents = this._onDidChangeCustomChatModes.event;
+	private readonly _onDidChangeCustomAgents = new Emitter<void>();
+	readonly onDidChangeCustomAgents = this._onDidChangeCustomAgents.event;
 
 	private readonly _onDidLogDiscovery = new Emitter<IPromptDiscoveryLogEntry>();
 	readonly onDidLogDiscovery: Event<IPromptDiscoveryLogEntry> = this._onDidLogDiscovery.event;
@@ -28,7 +28,7 @@ export class MockPromptsService implements IPromptsService {
 
 	setCustomModes(modes: ICustomAgent[]): void {
 		this._customModes = modes;
-		this._onDidChangeCustomChatModes.fire();
+		this._onDidChangeCustomAgents.fire();
 	}
 
 	async getCustomAgents(token: CancellationToken, sessionResource?: URI): Promise<readonly ICustomAgent[]> {
@@ -72,4 +72,7 @@ export class MockPromptsService implements IPromptsService {
 	getHooks(_token: CancellationToken, _sessionResource?: URI): Promise<any> { throw new Error('Method not implemented.'); }
 	getInstructionFiles(_token: CancellationToken, _sessionResource?: URI): Promise<readonly IPromptPath[]> { throw new Error('Method not implemented.'); }
 	dispose(): void { }
+	onDidChangeInstructions: Event<void> = Event.None;
+	onDidChangePromptFiles: Event<void> = Event.None;
+	onDidChangeSkills: Event<void> = Event.None;
 }

src/vscode-dts/vscode.proposed.chatPromptFiles.d.ts

@@ -103,6 +103,39 @@ declare module 'vscode' {
 	// #region Chat Provider Registration
 
 	export namespace chat {
+		/**
+		 * An event that fires when the list of {@link customAgents custom agents} changes.
+		 */
+		export const onDidChangeCustomAgents: Event<void>;
+
+		/**
+		 * The list of currently available custom agents. These are `.agent.md` files
+		 * from all sources (workspace, user, and extension-provided).
+		 */
+		export const customAgents: readonly ChatResource[];
+
+		/**
+		 * An event that fires when the list of {@link instructions instructions} changes.
+		 */
+		export const onDidChangeInstructions: Event<void>;
+
+		/**
+		 * The list of currently available instructions. These are `.instructions.md` files
+		 * from all sources (workspace, user, and extension-provided).
+		 */
+		export const instructions: readonly ChatResource[];
+
+		/**
+		 * An event that fires when the list of {@link skills skills} changes.
+		 */
+		export const onDidChangeSkills: Event<void>;
+
+		/**
+		 * The list of currently available skills. These are `SKILL.md` files
+		 * from all sources (workspace, user, and extension-provided).
+		 */
+		export const skills: readonly ChatResource[];
+
 		/**
 		 * Register a provider for custom agents.
 		 * @param provider The custom agent provider.