From f856d0bb58fedf2235724cae2cba691c12a2c5af Mon Sep 17 00:00:00 2001
From: Jake Macdonald <jakemac@google.com>
Date: Mon, 30 Jun 2025 14:20:42 -0700
Subject: [PATCH] remove the need for the experimental flag for the dart MCP
 server

Closes https://github.com/dart-lang/ai/issues/167

Change-Id: Ib3555f3ef9a89704f9b3a501e909fbb3e6dc3f0d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/437820
Commit-Queue: Jake Macdonald <jakemac@google.com>
Commit-Queue: Kenzie Davisson <kenzieschmoll@google.com>
Auto-Submit: Jake Macdonald <jakemac@google.com>
Reviewed-by: Kenzie Davisson <kenzieschmoll@google.com>
---
 .../lib/src/commands/dart_mcp_server.dart     | 11 ++--
 .../test/commands/mcp_server_test.dart        | 51 +++++++++----------
 2 files changed, 29 insertions(+), 33 deletions(-)

diff --git a/pkg/dartdev/lib/src/commands/dart_mcp_server.dart b/pkg/dartdev/lib/src/commands/dart_mcp_server.dart
index f61229b7436..12083237176 100644
--- a/pkg/dartdev/lib/src/commands/dart_mcp_server.dart
+++ b/pkg/dartdev/lib/src/commands/dart_mcp_server.dart
@@ -12,9 +12,7 @@ class DartMCPServerCommand extends DartdevCommand {
   static const String cmdName = 'mcp-server';
 
   static const String cmdDescription = '''
-A stdio based Model Context Protocol (MCP) server to aid in Dart and Flutter development.
-
-EXPERIMENTAL: This tool may change dramatically or disappear at any time.''';
+A stdio based Model Context Protocol (MCP) server to aid in Dart and Flutter development.''';
 
   static const _forceRootsFallbackFlag = 'force-roots-fallback';
   static const _experimentFlag = 'experimental-mcp-server';
@@ -33,6 +31,9 @@ EXPERIMENTAL: This tool may change dramatically or disappear at any time.''';
             'support it.',
       )
       ..addFlag(_experimentFlag,
+          // This flag is no longer required but we are leaving it in for
+          // backwards compatibility.
+          hide: true,
           defaultsTo: false,
           help: 'A required flag in order to use this command. Passing this '
               'flag is an acknowledgement that you understand it is an '
@@ -45,10 +46,6 @@ EXPERIMENTAL: This tool may change dramatically or disappear at any time.''';
   @override
   Future<int> run() async {
     final args = argResults!;
-    if (!args.flag(_experimentFlag)) {
-      log.stderr('Missing required flag --$_experimentFlag\n\n$usage');
-      return 64;
-    }
     try {
       VmInteropHandler.run(
         sdk.dartAotRuntime,
diff --git a/pkg/dartdev/test/commands/mcp_server_test.dart b/pkg/dartdev/test/commands/mcp_server_test.dart
index 071fc622636..4e189389bce 100644
--- a/pkg/dartdev/test/commands/mcp_server_test.dart
+++ b/pkg/dartdev/test/commands/mcp_server_test.dart
@@ -9,34 +9,33 @@ import 'package:test/test.dart';
 
 void main() {
   group('dart mcp-server', () {
-    test('can be connected with a client', () async {
-      final client = TestMCPClient();
-      addTearDown(client.shutdown);
-      final serverConnection = await client.connectStdioServer(
-          Platform.resolvedExecutable,
-          ['mcp-server', '--experimental-mcp-server']);
-      final initializeResult = await serverConnection.initialize(
-          InitializeRequest(
-              protocolVersion: ProtocolVersion.latestSupported,
-              capabilities: client.capabilities,
-              clientInfo: client.implementation));
+    for (var withExperiment in const [true, false]) {
+      test(
+          'can be connected with a client with${withExperiment ? '' : 'out'} the experiment flag',
+          () async {
+        final client = TestMCPClient();
+        addTearDown(client.shutdown);
+        final serverConnection =
+            await client.connectStdioServer(Platform.resolvedExecutable, [
+          'mcp-server',
+          if (withExperiment) '--experimental-mcp-server',
+        ]);
+        final initializeResult = await serverConnection.initialize(
+            InitializeRequest(
+                protocolVersion: ProtocolVersion.latestSupported,
+                capabilities: client.capabilities,
+                clientInfo: client.implementation));
 
-      expect(initializeResult.protocolVersion, ProtocolVersion.latestSupported);
-      serverConnection.notifyInitialized();
+        expect(
+            initializeResult.protocolVersion, ProtocolVersion.latestSupported);
+        serverConnection.notifyInitialized();
 
-      expect(
-        await serverConnection.listTools(ListToolsRequest()),
-        isNotEmpty,
-      );
-    });
-
-    test('requires the --experimental-mcp-server flag', () async {
-      final processResult =
-          await Process.run(Platform.resolvedExecutable, ['mcp-server']);
-      expect(processResult.exitCode, isNot(0));
-      expect(processResult.stderr,
-          contains('Missing required flag --experimental-mcp-server'));
-    });
+        expect(
+          await serverConnection.listTools(ListToolsRequest()),
+          isNotEmpty,
+        );
+      });
+    }
   });
 }