fix(@angular/cli): enforce MCP roots in get_best_practices tool

packages/angular/cli/src/commands/mcp/tools/best-practices.ts

@@ -20,6 +20,7 @@ import { createRequire } from 'node:module';
 import { dirname, isAbsolute, join, relative, resolve } from 'node:path';
 import { z } from 'zod';
 import { VERSION } from '../../../utilities/version';
+import { isAllowedWorkspacePath } from '../workspace-utils';
 import { type McpToolContext, declareTool } from './tool-registry';
 
 const bestPracticesInputSchema = z.object({
@@ -86,13 +87,35 @@ async function getBundledBestPractices(): Promise<string> {
  *
  * @param workspacePath The absolute path to the user's `angular.json` file.
  * @param logger The MCP tool context logger for reporting warnings.
+ * @param server The MCP server context, used to enforce the client's declared roots.
  * @returns A promise that resolves to an object containing the guide's content and source,
  *     or `undefined` if the guide could not be resolved.
  */
 async function getVersionSpecificBestPractices(
   workspacePath: string,
   logger: McpToolContext['logger'],
+  server: McpToolContext['server'],
 ): Promise<{ content: string; source: string } | undefined> {
+  if (server) {
+    try {
+      if (!(await isAllowedWorkspacePath(server, workspacePath))) {
+        logger.warn(
+          `Workspace path is outside the allowed MCP roots: ${workspacePath}. ` +
+            'Falling back to the bundled guide.',
+        );
+
+        return undefined;
+      }
+    } catch (e) {
+      logger.warn(
+        `Failed to verify workspace path '${workspacePath}': ` +
+          `${e instanceof Error ? e.message : e}. Falling back to the bundled guide.`,
+      );
+
+      return undefined;
+    }
+  }
+
   // 1. Resolve the path to package.json
   let pkgJsonPath: string;
   try {
@@ -175,7 +198,7 @@ async function getVersionSpecificBestPractices(
  * @param context The MCP tool context, containing the logger.
  * @returns An async function that serves as the tool's executor.
  */
-function createBestPracticesHandler({ logger }: McpToolContext) {
+function createBestPracticesHandler({ logger, server }: McpToolContext) {
   let bundledBestPractices: Promise<string>;
 
   return async (input: BestPracticesInput) => {
@@ -184,7 +207,11 @@ function createBestPracticesHandler({ logger }: McpToolContext) {
 
     // First, try to get the version-specific guide.
     if (input.workspacePath) {
-      const versionSpecific = await getVersionSpecificBestPractices(input.workspacePath, logger);
+      const versionSpecific = await getVersionSpecificBestPractices(
+        input.workspacePath,
+        logger,
+        server,
+      );
       if (versionSpecific) {
         content = versionSpecific.content;
         source = versionSpecific.source;

packages/angular/cli/src/commands/mcp/workspace-utils.ts

@@ -110,7 +110,7 @@ async function getAllowedWorkspaceRoots(server: McpToolContext['server']): Promi
     .filter((root): root is string => root !== null);
 }
 
-async function isAllowedWorkspacePath(
+export async function isAllowedWorkspacePath(
   server: McpToolContext['server'],
   workspacePath: string,
 ): Promise<boolean> {