@@ -5,6 +5,7 @@ import { type ClineSayTool, DEFAULT_WRITE_DELAY_MS } from "@roo-code/types"
 import { TelemetryService } from "@roo-code/telemetry"
 
 import { getReadablePath } from "../../utils/path"
+import { isPathOutsideWorkspace } from "../../utils/pathUtils"
 import { Task } from "../task/Task"
 import { formatResponse } from "../prompts/responses"
 import { fileExistsAtPath } from "../../utils/fs"
@@ -138,11 +139,13 @@ export class ApplyDiffTool extends BaseTool<"apply_diff"> {
 
 			// Check if file is write-protected
 			const isWriteProtected = task.rooProtectedController?.isWriteProtected(relPath) || false
+			const isOutsideWorkspace = isPathOutsideWorkspace(absolutePath)
 
 			const sharedMessageProps: ClineSayTool = {
 				tool: "appliedDiff",
 				path: getReadablePath(task.cwd, relPath),
 				diff: diffContent,
+				isOutsideWorkspace,
 			}
 
 			if (isPreventFocusDisruptionEnabled) {
@@ -332,10 +335,14 @@ export class ApplyDiffTool extends BaseTool<"apply_diff"> {
 			return
 		}
 
+		// relPath is guaranteed non-null after hasPathStabilized
+		const absolutePath = path.resolve(task.cwd, relPath!)
+
 		const sharedMessageProps: ClineSayTool = {
 			tool: "appliedDiff",
 			path: getReadablePath(task.cwd, relPath),
 			diff: diffContent,
+			isOutsideWorkspace: isPathOutsideWorkspace(absolutePath),
 		}
 
 		let toolProgressStatus
 
@@ -26,6 +26,10 @@ vi.mock("../../../utils/path", () => ({
 	getReadablePath: vi.fn().mockReturnValue("test/file.txt"),
 }))
 
+vi.mock("../../../utils/pathUtils", () => ({
+	isPathOutsideWorkspace: vi.fn().mockReturnValue(false),
+}))
+
 vi.mock("../../prompts/responses", () => ({
 	formatResponse: {
 		toolError: vi.fn((message: string) => `Error: ${message}`),
 
@@ -0,0 +1,236 @@
+// npx vitest run core/tools/__tests__/applyDiffTool.outsideWorkspace.spec.ts
+
+import fs from "fs/promises"
+import path from "path"
+
+import type { ClineSayTool } from "@roo-code/types"
+
+import type { ToolUse } from "../../../shared/tools"
+import { isPathOutsideWorkspace } from "../../../utils/pathUtils"
+import { checkAutoApproval } from "../../auto-approval"
+import { baseState } from "../../auto-approval/__tests__/fixtures"
+import type { Task } from "../../task/Task"
+import type { ToolCallbacks } from "../BaseTool"
+import { applyDiffTool } from "../ApplyDiffTool"
+
+vi.mock("@roo-code/telemetry", () => ({
+	TelemetryService: { instance: { captureDiffApplicationError: vi.fn() } },
+}))
+
+vi.mock("fs/promises", () => ({
+	default: {
+		readFile: vi.fn(),
+	},
+}))
+
+vi.mock("../../../utils/fs", () => ({
+	fileExistsAtPath: vi.fn().mockResolvedValue(true),
+}))
+
+vi.mock("../../../utils/path", () => ({
+	getReadablePath: vi.fn((_cwd: string, relPath?: string) => relPath ?? ""),
+}))
+
+vi.mock("../../../utils/pathUtils", () => ({
+	isPathOutsideWorkspace: vi.fn(),
+}))
+
+vi.mock("../../prompts/responses", () => ({
+	formatResponse: {
+		toolError: vi.fn((message: string) => `Error: ${message}`),
+		rooIgnoreError: vi.fn((filePath: string) => `Access denied: ${filePath}`),
+		createPrettyPatch: vi.fn(() => "mock-diff"),
+	},
+}))
+
+vi.mock("../../diff/stats", () => ({
+	sanitizeUnifiedDiff: vi.fn((diff: string) => diff),
+	computeDiffStats: vi.fn(() => ({ additions: 1, deletions: 1 })),
+}))
+
+vi.mock("vscode", () => ({
+	window: { showWarningMessage: vi.fn() },
+	env: { openExternal: vi.fn() },
+	Uri: { parse: vi.fn() },
+	workspace: {
+		get workspaceFolders() {
+			return [{ uri: { fsPath: path.resolve(CWD) } }]
+		},
+	},
+}))
+
+const CWD = "/workspace"
+const INSIDE_PATH = "src/index.ts"
+const OUTSIDE_PATH = "/home/me/.zshrc"
+const DIFF = "<<<<<<< SEARCH\nold\n=======\nnew\n>>>>>>> REPLACE"
+
+const cases = [
+	{ name: "a file outside the workspace", relPath: OUTSIDE_PATH, isOutside: true },
+	{ name: "a file inside the workspace", relPath: INSIDE_PATH, isOutside: false },
+]
+
+const approvalPaths = [
+	{ name: "diff view", preventFocusDisruption: false },
+	{ name: "preventFocusDisruption", preventFocusDisruption: true },
+]
+
+describe("ApplyDiffTool isOutsideWorkspace", () => {
+	let askApproval: ReturnType<typeof vi.fn<ToolCallbacks["askApproval"]>>
+
+	function createTask(preventFocusDisruption = false): Task {
+		const task = {
+			cwd: CWD,
+			consecutiveMistakeCount: 0,
+			consecutiveMistakeCountForApplyDiff: new Map<string, number>(),
+			didEditFile: false,
+			api: { getModel: () => ({ id: "claude-test" }) },
+			rooIgnoreController: { validateAccess: vi.fn().mockReturnValue(true) },
+			rooProtectedController: { isWriteProtected: vi.fn().mockReturnValue(false) },
+			providerRef: {
+				deref: vi.fn().mockReturnValue({
+					getState: vi.fn().mockResolvedValue({
+						diagnosticsEnabled: false,
+						writeDelayMs: 0,
+						experiments: { preventFocusDisruption },
+					}),
+				}),
+			},
+			diffStrategy: {
+				getName: () => "test",
+				applyDiff: vi.fn().mockResolvedValue({ success: true, content: "new\n" }),
+			},
+			diffViewProvider: {
+				editType: undefined,
+				originalContent: "",
+				open: vi.fn().mockResolvedValue(undefined),
+				update: vi.fn().mockResolvedValue(undefined),
+				reset: vi.fn().mockResolvedValue(undefined),
+				revertChanges: vi.fn().mockResolvedValue(undefined),
+				saveChanges: vi.fn().mockResolvedValue(undefined),
+				saveDirectly: vi.fn().mockResolvedValue(undefined),
+				scrollToFirstDiff: vi.fn(),
+				pushToolWriteResult: vi.fn().mockResolvedValue("Changes successfully applied."),
+			},
+			fileContextTracker: { trackFileContext: vi.fn().mockResolvedValue(undefined) },
+			say: vi.fn().mockResolvedValue(undefined),
+			ask: vi.fn().mockResolvedValue(undefined),
+			recordToolError: vi.fn(),
+			processQueuedMessages: vi.fn(),
+			sayAndCreateMissingParamError: vi.fn().mockResolvedValue("Missing param error"),
+		}
+		// The double provides only the Task members that ApplyDiffTool.execute and handlePartial read.
+		return task as unknown as Task
+	}
+
+	async function runExecute(relPath: string, isOutside: boolean, preventFocusDisruption = false): Promise<string> {
+		vi.mocked(isPathOutsideWorkspace).mockReturnValue(isOutside)
+
+		await applyDiffTool.execute({ path: relPath, diff: DIFF }, createTask(preventFocusDisruption), {
+			askApproval,
+			handleError: vi.fn().mockResolvedValue(undefined),
+			pushToolResult: vi.fn(),
+			toolCallId: "tool-call-1",
+		})
+
+		expect(askApproval).toHaveBeenCalledTimes(1)
+		return String(askApproval.mock.calls[0][1])
+	}
+
+	beforeEach(() => {
+		vi.clearAllMocks()
+		vi.mocked(isPathOutsideWorkspace).mockReset()
+		applyDiffTool.resetPartialState()
+		vi.mocked(fs.readFile).mockResolvedValue("old\n")
+		askApproval = vi.fn<ToolCallbacks["askApproval"]>().mockResolvedValue(true)
+	})
+
+	describe.each(approvalPaths)("approval payload ($name)", ({ preventFocusDisruption }) => {
+		it.each(cases)("reports isOutsideWorkspace for $name", async ({ relPath, isOutside }) => {
+			const payload = JSON.parse(await runExecute(relPath, isOutside, preventFocusDisruption)) as ClineSayTool
+
+			expect(isPathOutsideWorkspace).toHaveBeenCalledWith(path.resolve(CWD, relPath))
+			expect(payload.tool).toBe("appliedDiff")
+			expect(payload.isOutsideWorkspace).toBe(isOutside)
+		})
+	})
+
+	it.each(cases)("reports isOutsideWorkspace in the partial preview for $name", async ({ relPath, isOutside }) => {
+		vi.mocked(isPathOutsideWorkspace).mockReturnValue(isOutside)
+		const task = createTask()
+		const block: ToolUse<"apply_diff"> = {
+			type: "tool_use",
+			name: "apply_diff",
+			params: { path: relPath, diff: DIFF },
+			partial: true,
+		}
+
+		// The first call records the path; the second call sees it stable and asks.
+		await applyDiffTool.handlePartial(task, block)
+		await applyDiffTool.handlePartial(task, block)
+
+		expect(task.ask).toHaveBeenCalledTimes(1)
+		const payload = JSON.parse(String(vi.mocked(task.ask).mock.calls[0][1])) as ClineSayTool
+		expect(isPathOutsideWorkspace).toHaveBeenCalledWith(path.resolve(CWD, relPath))
+		expect(payload.isOutsideWorkspace).toBe(isOutside)
+	})
+
+	describe("with the real workspace check", () => {
+		it.each([
+			{
+				name: "a ../ path that resolves outside",
+				relPath: "../outside/config.json",
+				isOutside: true,
+				expected: "ask",
+			},
+			{ name: "a path inside", relPath: "src/index.ts", isOutside: false, expected: "approve" },
+		])("marks $name the workspace and returns $expected", async ({ relPath, isOutside, expected }) => {
+			const actual = await vi.importActual<typeof import("../../../utils/pathUtils")>("../../../utils/pathUtils")
+			vi.mocked(isPathOutsideWorkspace).mockImplementation(actual.isPathOutsideWorkspace)
+
+			await applyDiffTool.execute({ path: relPath, diff: DIFF }, createTask(), {
+				askApproval,
+				handleError: vi.fn().mockResolvedValue(undefined),
+				pushToolResult: vi.fn(),
+				toolCallId: "tool-call-1",
+			})
+
+			const text = String(askApproval.mock.calls[0][1])
+			const payload = JSON.parse(text) as ClineSayTool
+			expect(payload.isOutsideWorkspace).toBe(isOutside)
+
+			const result = await checkAutoApproval({
+				state: { ...baseState, alwaysAllowWrite: true },
+				cwd: CWD,
+				ask: "tool",
+				text,
+			})
+			expect(result).toEqual({ decision: expected })
+		})
+	})
+
+	describe("auto-approval decision with alwaysAllowWrite on", () => {
+		it.each([
+			{ ...cases[0], allowOutside: false, expected: "ask" },
+			{ ...cases[0], allowOutside: true, expected: "approve" },
+			{ ...cases[1], allowOutside: false, expected: "approve" },
+		])(
+			"returns $expected for $name when alwaysAllowWriteOutsideWorkspace is $allowOutside",
+			async ({ relPath, isOutside, allowOutside, expected }) => {
+				const text = await runExecute(relPath, isOutside)
+
+				const result = await checkAutoApproval({
+					state: {
+						...baseState,
+						alwaysAllowWrite: true,
+						alwaysAllowWriteOutsideWorkspace: allowOutside,
+					},
+					cwd: CWD,
+					ask: "tool",
+					text,
+				})
+
+				expect(result).toEqual({ decision: expected })
+			},
+		)
+	})
+})