pkgs/dart_mcp/example/tools_server.dart

// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// A server that implements the tools API using the [ToolsSupport] mixin.
library;

import 'dart:async';
import 'dart:io' as io;

import 'package:dart_mcp/server.dart';
import 'package:dart_mcp/stdio.dart';

void main() {
  // Create the server and connect it to stdio.
  MCPServerWithTools(stdioChannel(input: io.stdin, output: io.stdout));
}

/// This server uses the [ToolsSupport] mixin to provide tools to the client.
base class MCPServerWithTools extends MCPServer with ToolsSupport {
  MCPServerWithTools(super.channel)
    : super.fromStreamChannel(
        implementation: Implementation(
          name: 'An example dart server with tools support',
          version: '0.1.0',
        ),
        instructions: 'Just list and call the tools :D',
      ) {
    registerTool(concatTool, _concat);
  }

  /// A tool that concatenates a list of strings.
  final concatTool = Tool(
    name: 'concat',
    description: 'concatenates many string parts into one string',
    inputSchema: Schema.object(
      properties: {
        'parts': Schema.list(
          description: 'The parts to concatenate together',
          items: Schema.string(),
        ),
      },
      required: ['parts'],
    ),
  );

  /// The implementation of the `concat` tool.
  FutureOr<CallToolResult> _concat(CallToolRequest request) => CallToolResult(
    content: [
      TextContent(
        text: (request.arguments!['parts'] as List<dynamic>)
            .cast<String>()
            .join(''),
      ),
    ],
  );
}