feat: add automatic selection context to user messages

packages/types/src/task.ts

@@ -92,6 +92,12 @@ export interface CreateTaskOptions {
 	consecutiveMistakeLimit?: number
 	experiments?: Record<string, boolean>
 	initialTodos?: TodoItem[]
+	selectionContext?: {
+		selectedText: string
+		selectionFilePath: string
+		selectionStartLine: number
+		selectionEndLine: number
+	}
 }
 
 export enum TaskStatus {

src/core/environment/__tests__/getEnvironmentDetails.spec.ts

@@ -116,6 +116,7 @@ describe("getEnvironmentDetails", () => {
 				deref: vi.fn().mockReturnValue(mockProvider),
 				[Symbol.toStringTag]: "WeakRef",
 			} as unknown as WeakRef<ClineProvider>,
+			getAndClearSelectionContext: vi.fn().mockReturnValue(undefined),
 		}
 
 		// Mock other dependencies.
@@ -390,4 +391,60 @@ describe("getEnvironmentDetails", () => {
 		const result = await getEnvironmentDetails(cline as Task)
 		expect(result).toContain("REMINDERS")
 	})
+
+	describe("Selection Context", () => {
+		it("should include selection context when available", async () => {
+			const selectionContext = {
+				selectedText: "const x = 1;\nconst y = 2;",
+				selectionFilePath: "src/test.ts",
+				selectionStartLine: 10,
+				selectionEndLine: 11,
+			}
+
+			const clineWithSelection = {
+				...mockCline,
+				getAndClearSelectionContext: vi.fn().mockReturnValueOnce(selectionContext),
+			}
+
+			const result = await getEnvironmentDetails(clineWithSelection as unknown as Task)
+
+			expect(result).toContain("# Current Selection")
+			expect(result).toContain("File: src/test.ts:10-11")
+			expect(result).toContain("```")
+			expect(result).toContain("const x = 1;")
+			expect(result).toContain("const y = 2;")
+			expect(clineWithSelection.getAndClearSelectionContext).toHaveBeenCalledOnce()
+		})
+
+		it("should clear selection context after including it", async () => {
+			const selectionContext = {
+				selectedText: "test code",
+				selectionFilePath: "src/app.ts",
+				selectionStartLine: 5,
+				selectionEndLine: 5,
+			}
+
+			const clineWithSelection = {
+				...mockCline,
+				getAndClearSelectionContext: vi.fn().mockReturnValueOnce(selectionContext),
+			}
+
+			await getEnvironmentDetails(clineWithSelection as unknown as Task)
+
+			// Selection context should be cleared after use (method called once)
+			expect(clineWithSelection.getAndClearSelectionContext).toHaveBeenCalledOnce()
+		})
+
+		it("should not include selection section when no context is available", async () => {
+			const clineWithoutSelection = {
+				...mockCline,
+				getAndClearSelectionContext: vi.fn().mockReturnValueOnce(undefined),
+			}
+
+			const result = await getEnvironmentDetails(clineWithoutSelection as unknown as Task)
+
+			expect(result).not.toContain("# Current Selection")
+			expect(clineWithoutSelection.getAndClearSelectionContext).toHaveBeenCalledOnce()
+		})
+	})
 })

src/core/environment/getEnvironmentDetails.ts

@@ -32,6 +32,15 @@ export async function getEnvironmentDetails(cline: Task, includeFileDetails: boo
 		maxWorkspaceFiles = 200,
 	} = state ?? {}
 
+	// Include selection context if available (and automatically clear it)
+	const selectionContext = cline.getAndClearSelectionContext()
+	if (selectionContext) {
+		const { selectedText, selectionFilePath, selectionStartLine, selectionEndLine } = selectionContext
+		details += "\n\n# Current Selection"
+		details += `\nFile: ${selectionFilePath}:${selectionStartLine}-${selectionEndLine}`
+		details += `\n\`\`\`\n${selectedText}\n\`\`\``
+	}
+
 	// It could be useful for cline to know if the user went from one or no
 	// file to another between messages, so we always include this context.
 	details += "\n\n# VSCode Visible Files"

src/core/task/Task.ts

@@ -142,6 +142,12 @@ export interface TaskOptions extends CreateTaskOptions {
 	onCreated?: (task: Task) => void
 	initialTodos?: TodoItem[]
 	workspacePath?: string
+	selectionContext?: {
+		selectedText: string
+		selectionFilePath: string
+		selectionStartLine: number
+		selectionEndLine: number
+	}
 }
 
 export class Task extends EventEmitter<TaskEvents> implements TaskLike {
@@ -155,6 +161,15 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 
 	todoList?: TodoItem[]
 
+	// Temporary storage for selection context during message processing
+	// This is cleared after being used in getEnvironmentDetails
+	private _currentSelectionContext?: {
+		selectedText: string
+		selectionFilePath: string
+		selectionStartLine: number
+		selectionEndLine: number
+	}
+
 	readonly rootTask: Task | undefined = undefined
 	readonly parentTask: Task | undefined = undefined
 	readonly taskNumber: number
@@ -319,6 +334,7 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 		onCreated,
 		initialTodos,
 		workspacePath,
+		selectionContext,
 	}: TaskOptions) {
 		super()
 
@@ -440,7 +456,7 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 
 		if (startTask) {
 			if (task || images) {
-				this.startTask(task, images)
+				this.startTask(task, images, selectionContext)
 			} else if (historyItem) {
 				this.resumeTaskFromHistory()
 			} else {
@@ -449,6 +465,23 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 		}
 	}
 
+	/**
+	 * Get and clear the current selection context.
+	 * This ensures selection context is only used once and doesn't persist.
+	 */
+	public getAndClearSelectionContext():
+		| {
+				selectedText: string
+				selectionFilePath: string
+				selectionStartLine: number
+				selectionEndLine: number
+		  }
+		| undefined {
+		const context = this._currentSelectionContext
+		this._currentSelectionContext = undefined
+		return context
+	}
+
 	/**
 	 * Initialize the task mode from the provider state.
 	 * This method handles async initialization with proper error handling.
@@ -964,11 +997,24 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 		return result
 	}
 
-	handleWebviewAskResponse(askResponse: ClineAskResponse, text?: string, images?: string[]) {
+	handleWebviewAskResponse(
+		askResponse: ClineAskResponse,
+		text?: string,
+		images?: string[],
+		selectionContext?: {
+			selectedText: string
+			selectionFilePath: string
+			selectionStartLine: number
+			selectionEndLine: number
+		},
+	) {
 		this.askResponse = askResponse
 		this.askResponseText = text
 		this.askResponseImages = images
 
+		// Store selection context temporarily for use in the next getEnvironmentDetails call
+		this._currentSelectionContext = selectionContext
+
 		// Create a checkpoint whenever the user sends a message.
 		// Use allowEmpty=true to ensure a checkpoint is recorded even if there are no file changes.
 		// Suppress the checkpoint_saved chat row for this particular checkpoint to keep the timeline clean.
@@ -1244,7 +1290,16 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 	// Lifecycle
 	// Start / Resume / Abort / Dispose
 
-	private async startTask(task?: string, images?: string[]): Promise<void> {
+	private async startTask(
+		task?: string,
+		images?: string[],
+		selectionContext?: {
+			selectedText: string
+			selectionFilePath: string
+			selectionStartLine: number
+			selectionEndLine: number
+		},
+	): Promise<void> {
 		if (this.enableBridge) {
 			try {
 				await BridgeOrchestrator.subscribeToTask(this)
@@ -1264,6 +1319,9 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 		this.clineMessages = []
 		this.apiConversationHistory = []
 
+		// Store selection context temporarily for use in the first getEnvironmentDetails call
+		this._currentSelectionContext = selectionContext
+
 		// The todo list is already set in the constructor if initialTodos were provided
 		// No need to add any messages - the todoList property is already set
 

src/core/webview/webviewMessageHandler.ts

@@ -428,6 +428,44 @@ export const webviewMessageHandler = async (
 	}
 
 	switch (message.type) {
+		case "requestSelectionContext": {
+			// Get the active editor and its selection
+			const editor = vscode.window.activeTextEditor
+			if (editor && !editor.selection.isEmpty) {
+				const selection = editor.selection
+				const selectedText = editor.document.getText(selection)
+				const filePath = editor.document.uri.fsPath
+
+				// Convert to workspace-relative path if possible
+				const workspacePath = provider.cwd
+				let relativeFilePath: string
+				if (filePath.startsWith(workspacePath)) {
+					relativeFilePath = path.relative(workspacePath, filePath)
+				} else {
+					// File is outside workspace, use absolute path
+					relativeFilePath = filePath
+				}
+
+				// VSCode uses 0-based line numbers, convert to 1-based for user-friendly display
+				const startLine = selection.start.line + 1
+				const endLine = selection.end.line + 1
+
+				// Send selection context to webview only - don't store in task
+				await provider.postMessageToWebview({
+					type: "selectionContext",
+					selectedText,
+					selectionFilePath: relativeFilePath,
+					selectionStartLine: startLine,
+					selectionEndLine: endLine,
+				})
+			} else {
+				// No selection, send empty context
+				await provider.postMessageToWebview({
+					type: "selectionContext",
+				})
+			}
+			break
+		}
 		case "webviewDidLaunch":
 			// Load custom modes first
 			const customModes = await provider.customModesManager.getCustomModes()
@@ -507,7 +545,21 @@ export const webviewMessageHandler = async (
 			// agentically running promises in old instance don't affect our new
 			// task. This essentially creates a fresh slate for the new task.
 			try {
-				await provider.createTask(message.text, message.images)
+				await provider.createTask(message.text, message.images, undefined, {
+					selectionContext:
+						message.selectedText &&
+						message.selectionFilePath &&
+						typeof message.selectionStartLine === "number" &&
+						typeof message.selectionEndLine === "number"
+							? {
+									selectedText: message.selectedText,
+									selectionFilePath: message.selectionFilePath,
+									selectionStartLine: message.selectionStartLine,
+									selectionEndLine: message.selectionEndLine,
+								}
+							: undefined,
+				})
+
 				// Task created successfully - notify the UI to reset
 				await provider.postMessageToWebview({ type: "invoke", invoke: "newChat" })
 			} catch (error) {
@@ -523,9 +575,24 @@ export const webviewMessageHandler = async (
 			await provider.updateCustomInstructions(message.text)
 			break
 
-		case "askResponse":
-			provider.getCurrentTask()?.handleWebviewAskResponse(message.askResponse!, message.text, message.images)
+		case "askResponse": {
+			const task = provider.getCurrentTask()
+			// Pass selection context through to handleWebviewAskResponse
+			const selectionContext =
+				message.selectedText &&
+				message.selectionFilePath &&
+				typeof message.selectionStartLine === "number" &&
+				typeof message.selectionEndLine === "number"
+					? {
+							selectedText: message.selectedText,
+							selectionFilePath: message.selectionFilePath,
+							selectionStartLine: message.selectionStartLine,
+							selectionEndLine: message.selectionEndLine,
+						}
+					: undefined
+			task?.handleWebviewAskResponse(message.askResponse!, message.text, message.images, selectionContext)
 			break
+		}
 
 		case "updateSettings":
 			if (message.updatedSettings) {

src/shared/ExtensionMessage.ts

@@ -128,7 +128,12 @@ export interface ExtensionMessage {
 		| "dismissedUpsells"
 		| "organizationSwitchResult"
 		| "interactionRequired"
+		| "selectionContext"
 	text?: string
+	selectedText?: string
+	selectionFilePath?: string
+	selectionStartLine?: number
+	selectionEndLine?: number
 	payload?: any // Add a generic payload for now, can refine later
 	// Checkpoint warning message
 	checkpointWarning?: {

src/shared/WebviewMessage.ts

@@ -165,7 +165,12 @@ export interface WebviewMessage {
 		| "dismissUpsell"
 		| "getDismissedUpsells"
 		| "updateSettings"
+		| "requestSelectionContext"
 	text?: string
+	selectedText?: string
+	selectionFilePath?: string
+	selectionStartLine?: number
+	selectionEndLine?: number
 	editedMessageContent?: string
 	tab?: "settings" | "history" | "mcp" | "modes" | "chat" | "marketplace" | "cloud"
 	disabled?: boolean