mcp_annotations 0.1.1

Annotations for generating MCP server boilerplate and tools.

MCP Annotations

A lightweight annotation library for declaring Model Context Protocol (MCP) servers, tools, and parameter metadata in pure Dart.

This package is build-time only – it contains no runtime dependencies and should be included as a regular dependencies: entry in your pubspec.yaml alongside mcp_codegen.

---

Getting started

# pubspec.yaml
name: my_app
# ...
dependencies:
  mcp_annotations: ^0.1.0
  # Only required during development / code-gen – omit on publish.
  build_runner: ^2.4.0
  mcp_codegen: ^0.1.0

1. Add the annotations and generator to your project as shown above.
2. Annotate your functions, methods, or main() entry-point.
3. Run dart run build_runner build (or watch) to generate the MCP server / tool boilerplate.

Available annotations

Annotation	Use-case
@MCPTool	Marks a top-level function or static method as an MCP tool. Optional fields let you override the tool name, description, and parameter metadata.
@MCPParameter	Provides richer metadata (title / description) for an individual parameter defined in a @MCPTool.
@MCPServerApp	Marks a class or top-level function as the entry-point for an MCP server. The generator emits a concrete MCPServer subclass, bootstrap helpers, and – for classes – an extension run() method for easy launching.

See the API docs for the full list of fields and defaults.

Example

import 'package:mcp_annotations/mcp_annotations.dart';

@MCPServerApp(name: 'demo_server', version: '0.1.0')
class MCPDemoServer {
  const MCPDemoServer();

  @MCPTool(description: 'Adds two numbers.')
  num add(num a, num b) => a + b;
}

void main(List<String> args) {
  final server = MCPDemoServer();
  server.run(args);
}

You can now compile the generated server and use it with any MCP-compatible client.

Contributing

Contributions are welcome! Please read the CONTRIBUTING.md guide before submitting a pull-request.