Add ability to override prompts

src/extension/intents/node/agentIntent.ts

@@ -37,6 +37,7 @@ import { IDefaultIntentRequestHandlerOptions } from '../../prompt/node/defaultIn
 import { IDocumentContext } from '../../prompt/node/documentContext';
 import { IBuildPromptResult, IIntent, IIntentInvocation } from '../../prompt/node/intents';
 import { AgentPrompt, AgentPromptProps } from '../../prompts/node/agent/agentPrompt';
+import { PromptRegistry } from '../../prompts/node/agent/promptRegistry';
 import { PromptRenderer } from '../../prompts/node/base/promptRenderer';
 import { ICodeMapperService } from '../../prompts/node/codeMapper/codeMapperService';
 import { TemporalContextStats } from '../../prompts/node/inline/temporalContext';
@@ -259,6 +260,11 @@ export class AgentIntentInvocation extends EditCodeIntentInvocation implements I
 		const endpoint = toolTokens > 0 ? this.endpoint.cloneWithTokenOverride(safeBudget) : this.endpoint;
 		const summarizationEnabled = this.configurationService.getConfig(ConfigKey.SummarizeAgentConversationHistory) && this.prompt === AgentPrompt;
 		this.logService.debug(`AgentIntent: rendering with budget=${safeBudget} (baseBudget: ${baseBudget}, toolTokens: ${toolTokens}), summarizationEnabled=${summarizationEnabled}`);
+
+		// Get model options from prompt registry
+		const agentPromptResolver = await PromptRegistry.getPrompt(endpoint);
+		const modelOptions = agentPromptResolver && this.instantiationService.createInstance(agentPromptResolver).resolveModelOptions?.(endpoint);
+
 		let result: RenderPromptResult;
 		const props: AgentPromptProps = {
 			endpoint,
@@ -271,6 +277,7 @@ export class AgentIntentInvocation extends EditCodeIntentInvocation implements I
 			},
 			location: this.location,
 			enableCacheBreakpoints: summarizationEnabled,
+			...(modelOptions && { modelOptions }),
 			...this.extraPromptProps
 		};
 		try {

src/extension/prompts/node/agent/agentPrompt.tsx

@@ -7,7 +7,7 @@ import { BasePromptElementProps, Chunk, Image, PromptElement, PromptPiece, Promp
 import type { ChatRequestEditedFileEvent, LanguageModelToolInformation, NotebookEditor, TaskDefinition, TextEditor } from 'vscode';
 import { ChatLocation } from '../../../../platform/chat/common/commonTypes';
 import { ConfigKey, IConfigurationService } from '../../../../platform/configuration/common/configurationService';
-import { isHiddenModelB, isVSCModel, modelNeedsStrongReplaceStringHint } from '../../../../platform/endpoint/common/chatModelCapabilities';
+import { isVSCModel, modelNeedsStrongReplaceStringHint } from '../../../../platform/endpoint/common/chatModelCapabilities';
 import { CacheType } from '../../../../platform/endpoint/common/endpointTypes';
 import { IEnvService, OperatingSystem } from '../../../../platform/env/common/envService';
 import { getGitHubRepoInfoFromContext, IGitService } from '../../../../platform/git/common/gitService';
@@ -31,9 +31,10 @@ import { InternalToolReference } from '../../../prompt/common/intents';
 import { IPromptVariablesService } from '../../../prompt/node/promptVariablesService';
 import { ToolName } from '../../../tools/common/toolNames';
 import { TodoListContextPrompt } from '../../../tools/node/todoListContextPrompt';
-import { CopilotIdentityRules, GPT5CopilotIdentityRule } from '../base/copilotIdentity';
+import { CopilotIdentityRules } from '../base/copilotIdentity';
+import { CustomRender } from '../base/customRender';
 import { IPromptEndpoint, renderPromptElement } from '../base/promptRenderer';
-import { Gpt5SafetyRule, SafetyRules } from '../base/safetyRules';
+import { SafetyRules } from '../base/safetyRules';
 import { Tag } from '../base/tag';
 import { TerminalStatePromptElement } from '../base/terminalState';
 import { ChatVariables } from '../panel/chatVariables';
@@ -47,7 +48,7 @@ import { MultirootWorkspaceStructure } from '../panel/workspace/workspaceStructu
 import { AgentConversationHistory } from './agentConversationHistory';
 import './allAgentPrompts';
 import { AlternateGPTPrompt, DefaultAgentPrompt } from './defaultAgentInstructions';
-import { PromptRegistry } from './promptRegistry';
+import { ModelOptions, PromptRegistry } from './promptRegistry';
 import { SummarizedConversationHistory } from './summarizedConversationHistory';
 
 export interface AgentPromptProps extends GenericBasePromptElementProps {
@@ -65,6 +66,11 @@ export interface AgentPromptProps extends GenericBasePromptElementProps {
 	 * Codesearch mode, aka agentic Ask mode
 	 */
 	readonly codesearchMode?: boolean;
+
+	/**
+	 * Model-specific options
+	 */
+	readonly modelOptions?: ModelOptions;
 }
 
 /** Proportion of the prompt token budget any singular textual tool result is allowed to use. */
@@ -92,17 +98,10 @@ export class AgentPrompt extends PromptElement<AgentPromptProps> {
 		const baseAgentInstructions = <>
 			<SystemMessage>
 				You are an expert AI programming assistant, working with a user in the VS Code editor.<br />
-				{this.props.endpoint.family.startsWith('gpt-5') ? (
-					<>
-						<GPT5CopilotIdentityRule />
-						<Gpt5SafetyRule />
-					</>
-				) : (
-					<>
-						<CopilotIdentityRules />
-						<SafetyRules />
-					</>
-				)}
+				<CustomRender id='SystemMessageContent' overrides={this.props.modelOptions?.overrides}>
+					<CopilotIdentityRules />
+					<SafetyRules />
+				</CustomRender>
 			</SystemMessage>
 			{instructions}
 		</>;
@@ -129,6 +128,7 @@ export class AgentPrompt extends PromptElement<AgentPromptProps> {
 					endpoint={this.props.endpoint}
 					tools={this.props.promptContext.tools?.availableTools}
 					enableCacheBreakpoints={this.props.enableCacheBreakpoints}
+					modelOptions={this.props.modelOptions}
 				/>
 			</>;
 		} else {
@@ -141,7 +141,7 @@ export class AgentPrompt extends PromptElement<AgentPromptProps> {
 		}
 	}
 
-	private async getInstructions() {
+	private async getInstructions(): Promise<PromptPieceChild> {
 		const modelFamily = this.props.endpoint.family ?? 'unknown';
 
 		if (this.props.endpoint.family.startsWith('gpt-') && this.configurationService.getExperimentBasedConfig(ConfigKey.EnableAlternateGptPrompt, this.experimentationService)) {
@@ -268,9 +268,10 @@ export interface AgentUserMessageProps extends BasePromptElementProps {
 	readonly enableCacheBreakpoints?: boolean;
 	readonly editedFileEvents?: readonly ChatRequestEditedFileEvent[];
 	readonly sessionId?: string;
+	readonly modelOptions?: ModelOptions;
 }
 
-export function getUserMessagePropsFromTurn(turn: Turn, endpoint: IChatEndpoint): AgentUserMessageProps {
+export function getUserMessagePropsFromTurn(turn: Turn, endpoint: IChatEndpoint, modelOptions: ModelOptions | undefined): AgentUserMessageProps {
 	return {
 		isHistorical: true,
 		request: turn.request.message,
@@ -279,7 +280,8 @@ export function getUserMessagePropsFromTurn(turn: Turn, endpoint: IChatEndpoint)
 		toolReferences: turn.toolReferences,
 		chatVariables: turn.promptVariables ?? new ChatVariablesCollection(),
 		editedFileEvents: turn.editedFileEvents,
-		enableCacheBreakpoints: false // Should only be added to the current turn - some user messages may get them in Agent post-processing
+		enableCacheBreakpoints: false, // Should only be added to the current turn - some user messages may get them in Agent post-processing
+		modelOptions,
 	};
 }
 
@@ -296,7 +298,7 @@ export function getUserMessagePropsFromAgentProps(agentProps: AgentPromptProps):
 		editedFileEvents: agentProps.promptContext.editedFileEvents,
 		// TODO:@roblourens
 		sessionId: (agentProps.promptContext.tools?.toolInvocationToken as any)?.sessionId,
-
+		modelOptions: agentProps.modelOptions,
 	};
 }
 
@@ -333,14 +335,9 @@ export class AgentUserMessage extends PromptElement<AgentUserMessageProps> {
 		const hasEditFileTool = !!this.props.availableTools?.find(tool => tool.name === ToolName.EditFile);
 		const hasEditNotebookTool = !!this.props.availableTools?.find(tool => tool.name === ToolName.EditNotebook);
 		const hasTerminalTool = !!this.props.availableTools?.find(tool => tool.name === ToolName.CoreRunInTerminal);
-		const isGpt5 = this.props.endpoint.family.startsWith('gpt-5') && this.props.endpoint.family !== 'gpt-5-codex';
-		const attachmentHint = (this.props.endpoint.family === 'gpt-4.1' || isGpt5) && this.props.chatVariables.hasVariables() ?
-			' (See <attachments> above for file contents. You may not need to search or read the file again.)'
-			: '';
+		const hasVariables = this.props.chatVariables.hasVariables();
 		const hasToolsToEditNotebook = hasCreateFileTool || hasEditNotebookTool || hasReplaceStringTool || hasApplyPatchTool || hasEditFileTool;
 		const hasTodoTool = !!this.props.availableTools?.find(tool => tool.name === ToolName.CoreManageTodoList);
-		const isHiddenModelBFlag = await isHiddenModelB(this.props.endpoint);
-		const shouldUseUserQuery = this.props.endpoint.family.startsWith('grok-code') || isHiddenModelBFlag;
 
 		return (
 			<>
@@ -368,7 +365,11 @@ export class AgentUserMessage extends PromptElement<AgentUserMessageProps> {
 						{getExplanationReminder(this.props.endpoint.family, hasTodoTool)}
 						{getVSCModelReminder(shouldIncludePreamble)}
 					</Tag>
-					{query && <Tag name={shouldUseUserQuery ? 'user_query' : 'userRequest'} priority={900} flexGrow={7}>{query + attachmentHint}</Tag>}
+					{query && <Tag name={this.props.modelOptions?.shouldUseUserQuery ? 'user_query' : 'userRequest'} priority={900} flexGrow={7}>
+						<CustomRender id='UserMessageContent' overrides={this.props.modelOptions?.overrides} args={{ query, hasVariables }}>
+							{query}
+						</CustomRender>
+					</Tag>}
 					{this.props.enableCacheBreakpoints && <cacheBreakpoint type={CacheType} />}
 				</UserMessage>
 			</>

src/extension/prompts/node/agent/openAIPrompts.tsx

@@ -8,14 +8,16 @@ import { ConfigKey, IConfigurationService } from '../../../../platform/configura
 import { IChatEndpoint } from '../../../../platform/networking/common/networking';
 import { IExperimentationService } from '../../../../platform/telemetry/common/nullExperimentationService';
 import { ToolName } from '../../../tools/common/toolNames';
+import { GPT5CopilotIdentityRule } from '../base/copilotIdentity';
 import { InstructionMessage } from '../base/instructionMessage';
 import { ResponseTranslationRules } from '../base/responseTranslationRules';
+import { Gpt5SafetyRule } from '../base/safetyRules';
 import { Tag } from '../base/tag';
 import { EXISTING_CODE_MARKER } from '../panel/codeBlockFormattingRules';
 import { MathIntegrationRules } from '../panel/editorIntegrationRules';
 import { KeepGoingReminder } from './agentPrompt';
 import { ApplyPatchInstructions, CodesearchModeInstructions, DefaultAgentPromptProps, detectToolCapabilities, GenericEditingTips, McpToolInstructions, NotebookInstructions } from './defaultAgentInstructions';
-import { IAgentPrompt, PromptConstructor, PromptRegistry } from './promptRegistry';
+import { IAgentPrompt, ModelOptions, PromptConstructor, PromptRegistry } from './promptRegistry';
 
 export class DefaultOpenAIAgentPrompt extends PromptElement<DefaultAgentPromptProps> {
 	async render(state: void, sizing: PromptSizing) {
@@ -720,6 +722,23 @@ class OpenAIPromptResolver implements IAgentPrompt {
 
 		return DefaultOpenAIAgentPrompt;
 	}
+
+	resolveModelOptions(endpoint: IChatEndpoint): ModelOptions | undefined {
+		return {
+			overrides: {
+				SystemMessageContent: endpoint.model?.startsWith('gpt-5') ? () => <>
+					<GPT5CopilotIdentityRule />
+					<Gpt5SafetyRule />
+				</> : undefined,
+				UserMessageContent: (endpoint.family.startsWith('gpt-5') && endpoint.family !== 'gpt-5-codex') || (endpoint.family === 'gpt-4.1') ? ({ query, hasVariables }) => {
+					if (hasVariables) {
+						return <>{query + ' (See <attachments> above for file contents. You may not need to search or read the file again.)'}</>;
+					}
+					return <>{query}</>;
+				} : undefined
+			}
+		};
+	}
 }
 
 PromptRegistry.registerPrompt(OpenAIPromptResolver);

src/extension/prompts/node/agent/promptRegistry.ts

@@ -3,14 +3,23 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { PromptElement } from '@vscode/prompt-tsx';
+import { PromptElement, PromptPiece } from '@vscode/prompt-tsx';
 import type { IChatEndpoint } from '../../../../platform/networking/common/networking';
 import { DefaultAgentPromptProps } from './defaultAgentInstructions';
 
+export interface ModelOptions {
+	readonly shouldUseUserQuery?: boolean;
+	readonly overrides?: {
+		readonly SystemMessageContent?: () => PromptElement | PromptPiece;
+		readonly UserMessageContent?: (props: { query: string; hasVariables: boolean }) => PromptElement | PromptPiece;
+	};
+}
+
 export type PromptConstructor = new (props: DefaultAgentPromptProps, ...args: any[]) => PromptElement<DefaultAgentPromptProps>;
 
 export interface IAgentPrompt {
 	resolvePrompt(endpoint: IChatEndpoint): PromptConstructor | undefined;
+	resolveModelOptions?(endpoint: IChatEndpoint): ModelOptions | undefined;
 }
 
 export interface IAgentPromptCtor {

src/extension/prompts/node/agent/summarizedConversationHistory.tsx

@@ -36,6 +36,7 @@ import { renderPromptElement } from '../base/promptRenderer';
 import { Tag } from '../base/tag';
 import { ChatToolCalls } from '../panel/toolCalling';
 import { AgentPrompt, AgentPromptProps, AgentUserMessage, getUserMessagePropsFromAgentProps, getUserMessagePropsFromTurn, KeepGoingReminder } from './agentPrompt';
+import { ModelOptions } from './promptRegistry';
 import { SimpleSummarizedHistory } from './simpleSummarizedHistoryPrompt';
 
 export interface ConversationHistorySummarizationPromptProps extends SummarizedAgentHistoryProps {
@@ -274,7 +275,7 @@ class ConversationHistory extends PromptElement<SummarizedAgentHistoryProps> {
 				// We have a summary for a tool call round that was part of this turn
 				turnComponents.push(<SummaryMessageElement endpoint={this.props.endpoint} summaryText={summaryForTurn.text} />);
 			} else {
-				turnComponents.push(<AgentUserMessage flexGrow={1} {...getUserMessagePropsFromTurn(turn, this.props.endpoint)} />);
+				turnComponents.push(<AgentUserMessage flexGrow={1} {...getUserMessagePropsFromTurn(turn, this.props.endpoint, this.props.modelOptions)} />);
 			}
 
 			// Reverse the tool call rounds so they are in chronological order
@@ -322,6 +323,7 @@ export interface SummarizedAgentHistoryProps extends BasePromptElementProps {
 	readonly maxToolResultLength: number;
 	/** Optional hard cap on summary tokens; effective budget = min(prompt sizing tokenBudget, this value) */
 	readonly maxSummaryTokens?: number;
+	readonly modelOptions?: ModelOptions;
 }
 
 /**

src/extension/prompts/node/agent/test/agentPrompt.spec.tsx

@@ -29,6 +29,7 @@ import { ToolName } from '../../../../tools/common/toolNames';
 import { IToolsService } from '../../../../tools/common/toolsService';
 import { PromptRenderer } from '../../base/promptRenderer';
 import { AgentPrompt, AgentPromptProps } from '../agentPrompt';
+import { PromptRegistry } from '../promptRegistry';
 
 ["default", "gpt-4.1", "gpt-5", "claude-sonnet-4.5", "gemini-2.0-flash", "grok-code-fast-1"].forEach(family => {
 	suite(`AgentPrompt - ${family}`, () => {
@@ -75,11 +76,15 @@ import { AgentPrompt, AgentPromptProps } from '../agentPrompt';
 				promptContext = { ...promptContext, conversation };
 			}
 
+			const agentPromptResolver = await PromptRegistry.getPrompt(endpoint);
+			const modelOptions = agentPromptResolver && instaService.createInstance(agentPromptResolver).resolveModelOptions?.(endpoint);
+
 			const baseProps = {
 				priority: 1,
 				endpoint,
 				location: ChatLocation.Panel,
 				promptContext,
+				modelOptions,
 				...otherProps
 			};
 

src/extension/prompts/node/agent/xAIPrompts.tsx

@@ -14,7 +14,7 @@ import { EXISTING_CODE_MARKER } from '../panel/codeBlockFormattingRules';
 import { MathIntegrationRules } from '../panel/editorIntegrationRules';
 import { KeepGoingReminder } from './agentPrompt';
 import { CodesearchModeInstructions, DefaultAgentPromptProps, detectToolCapabilities, GenericEditingTips, McpToolInstructions, NotebookInstructions } from './defaultAgentInstructions';
-import { IAgentPrompt, PromptConstructor, PromptRegistry } from './promptRegistry';
+import { IAgentPrompt, ModelOptions, PromptConstructor, PromptRegistry } from './promptRegistry';
 
 class DefaultGrokCodeFastAgentPrompt extends PromptElement<DefaultAgentPromptProps> {
 	async render(state: void, sizing: PromptSizing) {
@@ -129,6 +129,12 @@ class XAIPromptResolver implements IAgentPrompt {
 	resolvePrompt(endpoint: IChatEndpoint): PromptConstructor | undefined {
 		return DefaultGrokCodeFastAgentPrompt;
 	}
+
+	resolveModelOptions(endpoint: IChatEndpoint): ModelOptions | undefined {
+		return {
+			shouldUseUserQuery: true,
+		};
+	}
 }
 
 

src/extension/prompts/node/base/customRender.tsx

@@ -0,0 +1,30 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+import { BasePromptElementProps, PromptElement, PromptPiece } from '@vscode/prompt-tsx';
+
+interface CustomRenderProps<T extends { [key: string]: (args: any) => PromptElement | PromptPiece }, K extends keyof T> extends BasePromptElementProps {
+	id: K;
+	overrides?: T;
+	args?: Parameters<T[K]>[0];
+}
+
+export class CustomRender<
+	T extends { [key: string]: (args: any) => PromptElement | PromptPiece },
+	K extends keyof T = keyof T
+> extends PromptElement<CustomRenderProps<T, K>> {
+	constructor(props: CustomRenderProps<T, K>) {
+		super(props);
+	}
+
+	render() {
+		if (this.props.overrides && Object.hasOwn(this.props.overrides, this.props.id)) {
+			const override = this.props.overrides[this.props.id];
+			if (typeof override === 'function') {
+				return override(this.props.args);
+			}
+		}
+		return <>{this.props.children}</>;
+	}
+}