MCP服务器框架

# Add to your pubspec.yaml dependencies
dart pub add fastmcp

# Add to your pubspec.yaml dev_dependencies
dart pub add --dev build_runner
dart pub add --dev fastmcp_generator

import 'package:fastmcp/fastmcp.dart';

part 'main.fastmcp.g.dart';

final app = FastMCP(name: 'MyFirstServer');

/// A simple tool that greets a user.
/// The doc comment is automatically used as the tool's description.
@Tool()
String greet({
  /// This description will auto assigned to the parameter
  required String name,
}) {
  return 'Hello, $name!';
}

void main() async {
  await app.run(
    registerGenerated: registerGenerated,
    transport: StdioTransport(),
  );
}

dart run build_runner build

$fastmcp/example dart run lib/main.dart
[INFO] 03:11:24.875 [McpEngine]: Registering generated functions...
[INFO] 03:11:24.877 [McpEngine]: Registration complete.
[INFO] 03:11:24.878 [McpEngine]: Engine connected to transport.
[INFO] 03:11:24.878 [McpEngine]: FastMCP server "FastMCP Showcase Server" is running...
[INFO] 03:11:24.884 [HttpTransport]: 🚀 HTTP server listening on http://0.0.0.0:8080/mcp

/// Provides the current server time.
@Resource(
  uri: 'server://time',
  mimeType: 'text/plain',
)
String getCurrentTime() => DateTime.now().toIso8601String();

@Prompt(name: 'code-review')
PromptResult createCodeReviewPrompt({required String language}) {
  return PromptResult(
    description: 'A system prompt for a $language code reviewer.',
    messages: [
      Message(
        role: 'system',
        content: TextContent(
          text: 'You are an expert code reviewer for the $language language...'
        ),
      ),
    ],
  );
}

@Tool()
Future<String> longTask(McpContext context, {int steps = 10}) async {
  for (int i = 1; i <= steps; i++) {
    // Check if the client cancelled the operation
    if (context.cancellationToken.isCancelled) {
      return 'Task Cancelled!';
    }
    // Report progress back to the client
    context.onProgress(i / steps, 'Processing step $i of $steps...');
    await Future.delayed(const Duration(seconds: 1));
  }
  return 'Task Complete!';
}

@Tool(
  name: 'admin-tool',
  meta: const {
    'permissions': ['admin'],
    'dangerLevel': 'high',
  },
)
void performAdminAction() { /* ... */ }