Merge main platform support into 2026 RC

Merge current main into dev/2026-07-28-rc to inherit the stable web/WASM export workaround and resolve PR #281 conflicts.

Author: leehack

CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Unreleased
 
+### Platform support
+
+- Inherited the stable 2.2.2 web/WASM-safe default export path, preserving
+  Dart IO native exports while working around pub.dev/pana 0.23.13 WASM
+  platform scoring for conditional exports.
+
 ### Conformance and interoperability
 
 - Updated official conformance gates to
@@ -112,6 +118,14 @@ explicitly and may still change before the official spec release.
 - Pointed prerelease package documentation links at `dev/2026-07-28-rc` so
   pub.dev users see the draft/RC docs that match the dev package.
 
+## 2.2.2
+
+### Platform support
+
+- Made the package barrel's default export path web/WASM-safe while preserving
+  Dart IO native exports, working around pub.dev/pana 0.23.13 WASM platform
+  scoring for conditional exports.
+
 ## 2.2.1
 
 ### Spec Alignment

lib/mcp_dart.dart

@@ -13,6 +13,10 @@ export 'src/types.dart'; // Exports shared types used across the MCP protocol.
 export 'src/shared/uuid.dart'; // Exports UUID generation utilities.
 export 'src/shared/logging.dart'; // Exports logging for customization
 
-// Platform-specific exports
-export 'src/exports.dart' // Stub export for other platforms
-    if (dart.library.js_interop) 'src/exports_web.dart'; // Web-specific exports
+// Platform-specific exports.
+//
+// Keep the default branch web/WASM-safe. Pub.dev currently runs pana 0.23.13,
+// which does not select `dart.library.js_interop` for WASM platform scoring and
+// would otherwise follow the native `dart:io` exports. Native platforms still
+// get the full implementation through `dart.library.io`.
+export 'src/exports_web.dart' if (dart.library.io) 'src/exports.dart';

lib/src/client/module_web.dart

@@ -6,5 +6,6 @@
 library;
 
 export './client.dart'; // Client-side implementation for MCP protocol.
+export './stdio_stub.dart'; // API-compatible stdio stubs.
 export './streamable_https.dart'; // Streamable HTTPS implementation.
 export './task_client.dart'; // Task client helper.

lib/src/client/stdio_stub.dart

@@ -0,0 +1,75 @@
+import 'dart:async';
+
+import 'package:mcp_dart/src/shared/transport.dart';
+import 'package:mcp_dart/src/types.dart';
+
+Never _unsupported() => throw UnsupportedError(
+      'StdioClientTransport is only available on Dart IO platforms.',
+    );
+
+/// Configuration parameters for launching a stdio server process.
+///
+/// This web/default-platform stub preserves the public API shape without
+/// importing `dart:io`. The real implementation is selected on Dart IO
+/// platforms through the package barrel's conditional export.
+class StdioServerParameters {
+  /// The executable command to run to start the server process.
+  final String command;
+
+  /// Command line arguments to pass to the executable.
+  final List<String> args;
+
+  /// Environment variables to use when spawning the process.
+  final Map<String, String>? environment;
+
+  /// How to handle the stderr stream of the child process on IO platforms.
+  final Object? stderrMode;
+
+  /// The working directory to use when spawning the process.
+  final String? workingDirectory;
+
+  /// Creates parameters for launching the stdio server.
+  const StdioServerParameters({
+    required this.command,
+    this.args = const [],
+    this.environment,
+    this.stderrMode,
+    this.workingDirectory,
+  });
+}
+
+/// Stub for the stdio client transport on platforms without `dart:io`.
+class StdioClientTransport implements Transport {
+  /// Creates a stdio client transport stub.
+  StdioClientTransport(this.serverParams);
+
+  /// Configuration for launching the server process.
+  final StdioServerParameters serverParams;
+
+  @override
+  void Function()? onclose;
+
+  @override
+  void Function(Error error)? onerror;
+
+  @override
+  void Function(JsonRpcMessage message)? onmessage;
+
+  @override
+  String? get sessionId => null;
+
+  /// Stderr is unavailable without a spawned process.
+  Stream<List<int>>? get stderr => null;
+
+  @override
+  Future<void> start() async => _unsupported();
+
+  @override
+  Future<void> close() async {
+    onclose?.call();
+  }
+
+  @override
+  Future<void> send(JsonRpcMessage message, {int? relatedRequestId}) async =>
+      _unsupported();
+}