MCP Ruby SDK

Ruby implementation of the Model Context Protocol (MCP).

Installation

Add this line to your application's Gemfile:

gem 'mcp'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install mcp

Quick Start

Here's a simple example of creating an MCP server with a calculator tool:

require 'mcp'

# Create an MCP server
server = MCP::Server.new(
  name: "Demo",
  version: "1.0.0"
)

# Add an addition tool
server.add_tool("add") do |params|
  result = params["a"] + params["b"]
  {
    content: [{ type: "text", text: result.to_s }]
  }
end

# Add a dynamic greeting resource
server.add_resource("greeting") do |uri, params|
  {
    contents: [{
      uri: uri,
      text: "Hello, #{params['name']}!"
    }]
  }
end

# Start the server using stdio transport
transport = MCP::Transport::Stdio.new
server.connect(transport)

Features

• Full implementation of the MCP specification
• Support for Resources, Tools, and Prompts
• Multiple transport options (stdio, HTTP/SSE)
• Easy-to-use high-level interfaces
• Async/await support
• Comprehensive type system

Documentation

For detailed documentation, please visit:

• API Documentation
• MCP Specification
• Examples

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/modelcontextprotocol/ruby-sdk. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.