refactor(@angular/cli): migrate MCP server to @modelcontextprotocol/server v2

clydin · alan-agius4 · commit b81b880c1bb7 · 2026-08-04T08:55:48.000+02:00
Upgrades the Model Context Protocol (MCP) server implementation from @modelcontextprotocol/sdk v1.30.0 to the role-specific @modelcontextprotocol/server v2.0.0 package. The monolithic SDK dependency has been replaced in both package.json and BUILD.bazel, with StdioServerTransport now resolved from the @modelcontextprotocol/server/stdio subpath.

In the MCP server initialization, notification handler registration for roots list changes now uses the spec method string instead of a Zod schema object. Additionally, tool-registry.ts introduces McpToolCallback and centrally wraps raw Zod schemas with z.object() during tool registration so individual tool declarations do not require schema syntax changes. Finally, low-level handlers in the zoneless migration tool have been updated to use ServerContext in place of RequestHandlerExtra, routing notifications and sampling requests through ctx.mcpReq.log and ctx.mcpReq.send.
diff --git a/packages/angular/cli/BUILD.bazel b/packages/angular/cli/BUILD.bazel
@@ -60,7 +60,7 @@ ts_project(
         ":node_modules/@angular-devkit/schematics",
         ":node_modules/@inquirer/prompts",
         ":node_modules/@listr2/prompt-adapter-inquirer",
-        ":node_modules/@modelcontextprotocol/sdk",
+        ":node_modules/@modelcontextprotocol/server",
         ":node_modules/jsonc-parser",
         ":node_modules/listr2",
         ":node_modules/npm-package-arg",
@@ -113,7 +113,7 @@ ts_project(
         ":angular-cli",
         ":node_modules/@angular-devkit/core",
         ":node_modules/@angular-devkit/schematics",
-        ":node_modules/@modelcontextprotocol/sdk",
+        ":node_modules/@modelcontextprotocol/server",
         ":node_modules/yargs",
         "//:node_modules/@types/semver",
         "//:node_modules/@types/yargs",
diff --git a/packages/angular/cli/package.json b/packages/angular/cli/package.json
@@ -17,7 +17,7 @@
     "@angular-devkit/schematics": "workspace:0.0.0-PLACEHOLDER",
     "@inquirer/prompts": "8.5.2",
     "@listr2/prompt-adapter-inquirer": "4.2.5",
-    "@modelcontextprotocol/sdk": "1.30.0",
+    "@modelcontextprotocol/server": "2.0.0",
     "@schematics/angular": "workspace:0.0.0-PLACEHOLDER",
     "jsonc-parser": "3.3.1",
     "listr2": "11.0.0",
diff --git a/packages/angular/cli/src/commands/mcp/cli.ts b/packages/angular/cli/src/commands/mcp/cli.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
+import { StdioServerTransport } from '@modelcontextprotocol/server/stdio';
 import type { Argv } from 'yargs';
 import {
   CommandModule,
diff --git a/packages/angular/cli/src/commands/mcp/mcp-server.ts b/packages/angular/cli/src/commands/mcp/mcp-server.ts
@@ -6,8 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
-import { RootsListChangedNotificationSchema } from '@modelcontextprotocol/sdk/types.js';
+import { McpServer } from '@modelcontextprotocol/server';
 import { join, normalize } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import type { AngularWorkspace } from '../../utilities/config';
@@ -134,7 +133,7 @@ for equivalent actions.
           restrictedHost.setRoots(searchRoots);
 
           if (clientCapabilities.roots.listChanged) {
-            server.server.setNotificationHandler(RootsListChangedNotificationSchema, async () => {
+            server.server.setNotificationHandler('notifications/roots/list_changed', async () => {
               try {
                 const { roots: updatedRoots } = await server.server.listRoots();
                 const updatedSearchRoots =
diff --git a/packages/angular/cli/src/commands/mcp/resources/instructions.ts b/packages/angular/cli/src/commands/mcp/resources/instructions.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import type { McpServer } from '@modelcontextprotocol/server';
 import { readFile } from 'node:fs/promises';
 import { join } from 'node:path';
 
diff --git a/packages/angular/cli/src/commands/mcp/testing/test-utils.ts b/packages/angular/cli/src/commands/mcp/testing/test-utils.ts
@@ -7,7 +7,7 @@
  */
 
 import { workspaces } from '@angular-devkit/core';
-import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import { McpServer } from '@modelcontextprotocol/server';
 import { AngularWorkspace } from '../../../utilities/config';
 import { type Devserver } from '../devserver';
 import { Host } from '../host';
diff --git a/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/migrate-single-file.ts b/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/migrate-single-file.ts
@@ -6,8 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { RequestHandlerExtra } from '@modelcontextprotocol/sdk/shared/protocol';
-import type { ServerNotification, ServerRequest } from '@modelcontextprotocol/sdk/types';
+import type { ServerContext } from '@modelcontextprotocol/server';
 import type { SourceFile } from 'typescript';
 import type { Host } from '../../host';
 import { analyzeForUnsupportedZoneUses } from './analyze-for-unsupported-zone-uses';
@@ -22,7 +21,7 @@ const supportedStrategies: ReadonlySet<string> = new Set(['OnPush', 'Default', '
 export async function migrateSingleFile(
   sourceFile: SourceFile,
   host: Host,
-  extras: RequestHandlerExtra<ServerRequest, ServerNotification>,
+  extras: ServerContext,
 ): Promise<MigrationResponse | null> {
   const testBedSpecifier = await getImportSpecifier(sourceFile, '@angular/core/testing', 'TestBed');
   const isTestFile = sourceFile.fileName.endsWith('.spec.ts') || !!testBedSpecifier;
diff --git a/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/migrate-single-file_spec.ts b/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/migrate-single-file_spec.ts
@@ -6,16 +6,17 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { RequestHandlerExtra } from '@modelcontextprotocol/sdk/shared/protocol';
-import type { ServerNotification, ServerRequest } from '@modelcontextprotocol/sdk/types';
+import type { ServerContext } from '@modelcontextprotocol/server';
 import ts from 'typescript';
 import { createMockHost } from '../../testing/test-utils';
 import { migrateSingleFile } from './migrate-single-file';
 
 const fakeExtras = {
-  sendDebugMessage: jasmine.createSpy(),
-  sendNotification: jasmine.createSpy(),
-} as unknown as RequestHandlerExtra<ServerRequest, ServerNotification>;
+  mcpReq: {
+    log: jasmine.createSpy(),
+    notify: jasmine.createSpy(),
+  },
+} as unknown as ServerContext;
 
 describe('migrateSingleFile', () => {
   const mockHost = createMockHost();
diff --git a/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/send-debug-message.ts b/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/send-debug-message.ts
@@ -6,18 +6,8 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { RequestHandlerExtra } from '@modelcontextprotocol/sdk/shared/protocol';
-import type { ServerNotification, ServerRequest } from '@modelcontextprotocol/sdk/types';
+import type { ServerContext } from '@modelcontextprotocol/server';
 
-export function sendDebugMessage(
-  message: string,
-  { sendNotification }: RequestHandlerExtra<ServerRequest, ServerNotification>,
-): void {
-  void sendNotification({
-    method: 'notifications/message',
-    params: {
-      level: 'debug',
-      data: message,
-    },
-  });
+export function sendDebugMessage(message: string, ctx: ServerContext): void {
+  void ctx.mcpReq.log('debug', message);
 }
diff --git a/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/zoneless-migration.ts b/packages/angular/cli/src/commands/mcp/tools/onpush-zoneless-migration/zoneless-migration.ts
@@ -6,8 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { RequestHandlerExtra } from '@modelcontextprotocol/sdk/shared/protocol';
-import type { ServerNotification, ServerRequest } from '@modelcontextprotocol/sdk/types';
+import type { ServerContext } from '@modelcontextprotocol/server';
 import { join } from 'node:path';
 import type { SourceFile } from 'typescript';
 import { z } from 'zod';
@@ -57,7 +56,7 @@ change detection (a prerequisite for zoneless applications).
 export async function registerZonelessMigrationTool(
   fileOrDirPath: string,
   host: Host,
-  extras: RequestHandlerExtra<ServerRequest, ServerNotification>,
+  extras: ServerContext,
 ) {
   let filesWithComponents, componentTestFiles, zoneFiles, categorizationErrors;
   try {
@@ -114,7 +113,7 @@ export async function registerZonelessMigrationTool(
 async function discoverAndCategorizeFiles(
   fileOrDirPath: string,
   host: Host,
-  extras: RequestHandlerExtra<ServerRequest, ServerNotification>,
+  extras: ServerContext,
 ) {
   const filePaths: string[] = [];
   const componentTestFiles = new Set<SourceFile>();
@@ -175,7 +174,7 @@ async function discoverAndCategorizeFiles(
 async function categorizeFile(
   sourceFile: SourceFile,
   host: Host,
-  extras: RequestHandlerExtra<ServerRequest, ServerNotification>,
+  extras: ServerContext,
   categorizedFiles: {
     filesWithComponents: Set<SourceFile>;
     componentTestFiles: Set<SourceFile>;
@@ -216,11 +215,11 @@ async function categorizeFile(
 }
 
 async function rankComponentFilesForMigration(
-  { sendRequest }: RequestHandlerExtra<ServerRequest, ServerNotification>,
+  ctx: ServerContext,
   componentFiles: SourceFile[],
 ): Promise<SourceFile[]> {
   try {
-    const response = await sendRequest(
+    const response = await ctx.mcpReq.send(
       {
         method: 'sampling/createMessage',
         params: {
diff --git a/packages/angular/cli/src/commands/mcp/tools/tool-registry.ts b/packages/angular/cli/src/commands/mcp/tools/tool-registry.ts
@@ -6,15 +6,17 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import type { McpServer, ToolCallback } from '@modelcontextprotocol/sdk/server/mcp.js';
-import type { ToolAnnotations } from '@modelcontextprotocol/sdk/types';
-import type { ZodRawShape } from 'zod';
+import type {
+  McpServer,
+  ServerContext,
+  ToolAnnotations,
+  ToolCallback,
+} from '@modelcontextprotocol/server';
+import { type ZodRawShape, z } from 'zod';
 import type { AngularWorkspace } from '../../../utilities/config';
 import type { Devserver } from '../devserver';
 import type { Host } from '../host';
 
-type ToolConfig = Parameters<McpServer['registerTool']>[1];
-
 export interface McpToolContext {
   server: McpServer;
   workspace?: AngularWorkspace;
@@ -24,9 +26,14 @@ export interface McpToolContext {
   host: Host;
 }
 
+export type McpToolCallback<TInput extends ZodRawShape = ZodRawShape> = (
+  args: z.infer<z.ZodObject<TInput>>,
+  ctx: ServerContext,
+) => ReturnType<ToolCallback>;
+
 export type McpToolFactory<TInput extends ZodRawShape> = (
   context: McpToolContext,
-) => ToolCallback<TInput> | Promise<ToolCallback<TInput>>;
+) => McpToolCallback<TInput> | Promise<McpToolCallback<TInput>>;
 
 export interface McpToolDeclaration<TInput extends ZodRawShape, TOutput extends ZodRawShape> {
   name: string;
@@ -75,6 +82,14 @@ export async function registerTools(
       config.annotations.openWorldHint = !isLocalOnly;
     }
 
-    server.registerTool(name, config, handler);
+    server.registerTool(
+      name,
+      {
+        ...config,
+        inputSchema: config.inputSchema ? z.object(config.inputSchema) : undefined,
+        outputSchema: config.outputSchema ? z.object(config.outputSchema) : undefined,
+      },
+      handler,
+    );
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
