feat: add 'onlychat' mode with specific role definition and instructions

Author: NaccOll

packages/types/src/mode.ts

@@ -192,4 +192,14 @@ export const DEFAULT_MODES: readonly ModeConfig[] = [
 		customInstructions:
 			"Your role is to coordinate complex workflows by delegating tasks to specialized modes. As an orchestrator, you should:\n\n1. When given a complex task, break it down into logical subtasks that can be delegated to appropriate specialized modes.\n\n2. For each subtask, use the `new_task` tool to delegate. Choose the most appropriate mode for the subtask's specific goal and provide comprehensive instructions in the `message` parameter. These instructions must include:\n    *   All necessary context from the parent task or previous subtasks required to complete the work.\n    *   A clearly defined scope, specifying exactly what the subtask should accomplish.\n    *   An explicit statement that the subtask should *only* perform the work outlined in these instructions and not deviate.\n    *   An instruction for the subtask to signal completion by using the `attempt_completion` tool, providing a concise yet thorough summary of the outcome in the `result` parameter, keeping in mind that this summary will be the source of truth used to keep track of what was completed on this project.\n    *   A statement that these specific instructions supersede any conflicting general instructions the subtask's mode might have.\n\n3. Track and manage the progress of all subtasks. When a subtask is completed, analyze its results and determine the next steps.\n\n4. Help the user understand how the different subtasks fit together in the overall workflow. Provide clear reasoning about why you're delegating specific tasks to specific modes.\n\n5. When all subtasks are completed, synthesize the results and provide a comprehensive overview of what was accomplished.\n\n6. Ask clarifying questions when necessary to better understand how to break down complex tasks effectively.\n\n7. Suggest improvements to the workflow based on the results of completed subtasks.\n\nUse subtasks to maintain clarity. If a request significantly shifts focus or requires a different expertise (mode), consider creating a subtask rather than overloading the current one.",
 	},
+	{
+		slug: "onlychat",
+		name: "🗨️OnlyChat",
+		roleDefinition:
+			"You are Roo, a knowledgeable technical assistant focused on answering questions and providing information about software development, technology, and related topics.",
+		whenToUse:
+			"Use this mode for pure conversational interactions without any tool execution. Ideal for discussions, explanations, and Q&A without file operations or code changes.",
+		groups: [],
+		description: "A chat-only mode without tool execution capabilities",
+	},
 ] as const

src/core/assistant-message/presentAssistantMessage.ts

@@ -5,7 +5,7 @@ import type { ToolName, ClineAsk, ToolProgressStatus } from "@roo-code/types"
 import { TelemetryService } from "@roo-code/telemetry"
 
 import { defaultModeSlug, getModeBySlug } from "../../shared/modes"
-import type { ToolParamName, ToolResponse } from "../../shared/tools"
+import type { ToolParamName, ToolResponse, ToolUse } from "../../shared/tools"
 
 import { fetchInstructionsTool } from "../tools/fetchInstructionsTool"
 import { listFilesTool } from "../tools/listFilesTool"
@@ -79,6 +79,33 @@ export async function presentAssistantMessage(cline: Task) {
 
 	const block = cloneDeep(cline.assistantMessageContent[cline.currentStreamingContentIndex]) // need to create copy bc while stream is updating the array, it could be updating the reference block properties too
 
+	// If block is partial, remove partial closing tag so its not
+	// presented to user.
+	const removeClosingTag = (tag: ToolParamName, text?: string): string => {
+		if (!block.partial) {
+			return text || ""
+		}
+
+		if (!text) {
+			return ""
+		}
+
+		// This regex dynamically constructs a pattern to match the
+		// closing tag:
+		// - Optionally matches whitespace before the tag.
+		// - Matches '<' or '</' optionally followed by any subset of
+		//   characters from the tag name.
+		const tagRegex = new RegExp(
+			`\\s?<\/?${tag
+				.split("")
+				.map((char) => `(?:${char})?`)
+				.join("")}$`,
+			"g",
+		)
+
+		return text.replace(tagRegex, "")
+	}
+
 	switch (block.type) {
 		case "text": {
 			if (cline.didRejectTool || cline.didAlreadyUseTool) {
@@ -145,7 +172,27 @@ export async function presentAssistantMessage(cline: Task) {
 					}
 				}
 			}
-
+			const { mode } = (await cline.providerRef.deref()?.getState()) ?? {}
+			if (mode === "onlychat") {
+				await attemptCompletionTool(
+					cline,
+					{
+						type: "tool_use",
+						name: "attempt_completion",
+						params: {
+							result: content,
+						},
+						partial: block.partial,
+					} as ToolUse,
+					undefined as any,
+					undefined as any,
+					undefined as any,
+					removeClosingTag,
+					undefined as any,
+					undefined as any,
+				)
+				break
+			}
 			await cline.say("text", content, undefined, block.partial)
 			break
 		}
@@ -314,33 +361,6 @@ export async function presentAssistantMessage(cline: Task) {
 				pushToolResult(formatResponse.toolError(errorString))
 			}
 
-			// If block is partial, remove partial closing tag so its not
-			// presented to user.
-			const removeClosingTag = (tag: ToolParamName, text?: string): string => {
-				if (!block.partial) {
-					return text || ""
-				}
-
-				if (!text) {
-					return ""
-				}
-
-				// This regex dynamically constructs a pattern to match the
-				// closing tag:
-				// - Optionally matches whitespace before the tag.
-				// - Matches '<' or '</' optionally followed by any subset of
-				//   characters from the tag name.
-				const tagRegex = new RegExp(
-					`\\s?<\/?${tag
-						.split("")
-						.map((char) => `(?:${char})?`)
-						.join("")}$`,
-					"g",
-				)
-
-				return text.replace(tagRegex, "")
-			}
-
 			if (block.name !== "browser_action") {
 				await cline.browserSession.closeBrowser()
 			}

src/core/prompts/__tests__/system-prompt.spec.ts

@@ -669,6 +669,38 @@ describe("SYSTEM_PROMPT", () => {
 		expect(prompt).toContain("## update_todo_list")
 	})
 
+	it("should return only roleDefinition and customInstructions for onlychat mode", async () => {
+		const onlyChatMode: ModeConfig = {
+			slug: "onlychat",
+			name: "Only Chat",
+			roleDefinition: "You are a chat-only assistant.",
+			customInstructions: "Only chat instructions.",
+			groups: ["read"] as const,
+		}
+		const customModes = [onlyChatMode]
+		const prompt = await SYSTEM_PROMPT(
+			mockContext,
+			"/test/path",
+			false, // supportsComputerUse
+			undefined, // mcpHub
+			undefined, // diffStrategy
+			undefined, // browserViewportSize
+			"onlychat", // mode
+			undefined, // customModePrompts
+			customModes, // customModes
+			undefined, // globalCustomInstructions
+			true, // diffEnabled
+			undefined, // experiments
+			false, // enableMcpServerCreation
+			undefined, // language
+			undefined, // rooIgnoreInstructions
+			undefined, // partialReadsEnabled
+		)
+		expect(prompt).toContain("You are a chat-only assistant.")
+		expect(prompt).toContain("Only chat instructions.")
+		expect(prompt).not.toContain("apply_diff")
+	})
+
 	afterAll(() => {
 		vi.restoreAllMocks()
 	})

src/core/prompts/sections/modes.ts

@@ -19,6 +19,7 @@ MODES
 
 - These are the currently available modes:
 ${allModes
+	.filter((mode: ModeConfig) => mode.slug !== "onlychat")
 	.map((mode: ModeConfig) => {
 		let description: string
 		if (mode.whenToUse && mode.whenToUse.trim() !== "") {

src/core/prompts/system.ts

@@ -170,8 +170,10 @@ export const SYSTEM_PROMPT = async (
 	// Get full mode config from custom modes or fall back to built-in modes
 	const currentMode = getModeBySlug(mode, customModes) || modes.find((m) => m.slug === mode) || modes[0]
 
+	const isOnlyChatMode = currentMode.slug === "onlychat"
+
 	// If a file-based custom system prompt exists, use it
-	if (fileCustomSystemPrompt) {
+	if (fileCustomSystemPrompt || isOnlyChatMode) {
 		const { roleDefinition, baseInstructions: baseInstructionsForFile } = getModeSelection(
 			mode,
 			promptComponent,
@@ -193,7 +195,7 @@ export const SYSTEM_PROMPT = async (
 		// For file-based prompts, don't include the tool sections
 		return `${roleDefinition}
 
-${fileCustomSystemPrompt}
+${fileCustomSystemPrompt || ""}
 
 ${customInstructions}`
 	}