Add 'default agent' concept (#195599)

So that every request can be routed through an agent

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

@@ -185,6 +185,7 @@ class ExtHostChatAgent {
 	private _description: string | undefined;
 	private _fullName: string | undefined;
 	private _iconPath: URI | undefined;
+	private _isDefault: boolean | undefined;
 	private _onDidReceiveFeedback = new Emitter<vscode.ChatAgentResult2Feedback>();
 	private _onDidPerformAction = new Emitter<vscode.ChatAgentUserActionEvent>();
 
@@ -258,6 +259,7 @@ class ExtHostChatAgent {
 					icon: this._iconPath,
 					hasSlashCommands: this._slashCommandProvider !== undefined,
 					hasFollowup: this._followupProvider !== undefined,
+					isDefault: this._isDefault
 				});
 				updateScheduled = false;
 			});
@@ -304,6 +306,13 @@ class ExtHostChatAgent {
 				that._followupProvider = v;
 				updateMetadataSoon();
 			},
+			get isDefault() {
+				return that._isDefault;
+			},
+			set isDefault(v) {
+				that._isDefault = v;
+				updateMetadataSoon();
+			},
 			get onDidReceiveFeedback() {
 				return that._onDidReceiveFeedback.event;
 			},

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

@@ -329,7 +329,8 @@ class AgentCompletions extends Disposable {
 					return null;
 				}
 
-				const agents = this.chatAgentService.getAgents();
+				const agents = this.chatAgentService.getAgents()
+					.filter(a => !a.metadata.isDefault);
 				return <CompletionList>{
 					suggestions: agents.map((c, i) => {
 						const withAt = `@${c.id}`;

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

@@ -5,6 +5,7 @@
 
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { Emitter, Event } from 'vs/base/common/event';
+import { Iterable } from 'vs/base/common/iterator';
 import { Disposable, IDisposable, toDisposable } from 'vs/base/common/lifecycle';
 import { URI } from 'vs/base/common/uri';
 import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
@@ -36,7 +37,7 @@ export interface IChatAgentMetadata {
 	description?: string;
 	// subCommands: IChatAgentCommand[];
 	requireCommand?: boolean; // Do some agents not have a default action?
-	isImplicit?: boolean; // Only @workspace. slash commands get promoted to the top-level and this agent is invoked when those are used
+	isDefault?: boolean; // The agent invoked when no agent is specified
 	fullName?: string;
 	icon?: URI;
 }
@@ -69,6 +70,7 @@ export interface IChatAgentService {
 	getFollowups(id: string, sessionId: string, token: CancellationToken): Promise<IChatFollowup[]>;
 	getAgents(): Array<IChatAgent>;
 	getAgent(id: string): IChatAgent | undefined;
+	getDefaultAgent(): IChatAgent | undefined;
 	hasAgent(id: string): boolean;
 	updateAgent(id: string, updateMetadata: IChatAgentMetadata): void;
 }
@@ -112,6 +114,10 @@ export class ChatAgentService extends Disposable implements IChatAgentService {
 		this._onDidChangeAgents.fire();
 	}
 
+	getDefaultAgent(): IChatAgent | undefined {
+		return Iterable.find(this._agents.values(), a => !!a.agent.metadata.isDefault)?.agent;
+	}
+
 	getAgents(): Array<IChatAgent> {
 		return Array.from(this._agents.values(), v => v.agent);
 	}

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

@@ -507,7 +507,9 @@ export class ChatService extends Disposable implements IChatService {
 				let rawResponse: IChatResponse | null | undefined;
 				let agentOrCommandFollowups: Promise<IChatFollowup[] | undefined> | undefined = undefined;
 
-				if (typeof message === 'string' && agentPart) {
+				const defaultAgent = this.chatAgentService.getDefaultAgent();
+				if (typeof message === 'string' && (agentPart || defaultAgent)) {
+					const agent = (agentPart?.agent ?? defaultAgent)!;
 					const history: IChatMessage[] = [];
 					for (const request of model.getRequests()) {
 						if (!request.response) {
@@ -518,11 +520,11 @@ export class ChatService extends Disposable implements IChatService {
 						history.push({ role: ChatMessageRole.Assistant, content: request.response.response.asString() });
 					}
 
-					request = model.addRequest(parsedRequest, agentPart.agent);
+					request = model.addRequest(parsedRequest, agent);
 					const requestProps: IChatAgentRequest = {
 						sessionId,
 						requestId: generateUuid(),
-						message: message,
+						message,
 						variables: {},
 						command: agentSlashCommandPart?.command.name ?? '',
 					};
@@ -532,7 +534,7 @@ export class ChatService extends Disposable implements IChatService {
 						requestProps.message = varResult.prompt;
 					}
 
-					const agentResult = await this.chatAgentService.invokeAgent(agentPart.agent.id, requestProps, new Progress<IChatProgress>(p => {
+					const agentResult = await this.chatAgentService.invokeAgent(agent.id, requestProps, new Progress<IChatProgress>(p => {
 						progressCallback(p);
 					}), history, token);
 					rawResponse = {
@@ -541,7 +543,7 @@ export class ChatService extends Disposable implements IChatService {
 						timings: agentResult.timings
 					};
 					agentOrCommandFollowups = agentResult?.followUp ? Promise.resolve(agentResult.followUp) :
-						this.chatAgentService.getFollowups(agentPart.agent.id, sessionId, CancellationToken.None);
+						this.chatAgentService.getFollowups(agent.id, sessionId, CancellationToken.None);
 				} else if (commandPart && typeof message === 'string' && this.chatSlashCommandService.hasCommand(commandPart.slashCommand.command)) {
 					request = model.addRequest(parsedRequest);
 					// contributed slash commands

src/vs/workbench/services/extensions/common/extensionsApiProposals.ts

@@ -38,6 +38,7 @@ export const allApiProposals = Object.freeze({
 	createFileSystemWatcher: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.createFileSystemWatcher.d.ts',
 	customEditorMove: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.customEditorMove.d.ts',
 	debugFocus: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.debugFocus.d.ts',
+	defaultChatAgent: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.defaultChatAgent.d.ts',
 	diffCommand: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.diffCommand.d.ts',
 	diffContentOptions: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.diffContentOptions.d.ts',
 	documentFiltersExclusive: 'https://raw.githubusercontent.com/microsoft/vscode/main/src/vscode-dts/vscode.proposed.documentFiltersExclusive.d.ts',

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

@@ -0,0 +1,14 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+declare module 'vscode' {
+
+	export interface ChatAgent2 {
+		/**
+		 * When true, this agent is invoked by default when no other agent is being invoked
+		 */
+		isDefault?: boolean;
+	}
+}