Mcp On Ruby

MCP on Ruby

[](https://badge.fury.io/rb/mcponruby) [](https://opensource.org/licenses/MIT) [](https://www.ruby-lang.org/)

Model Context Protocol (MCP) server for Rails applications

Expose your Rails app as an AI accessible interface — define tools and resources the Rails way.

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Features

🚀 Production-Ready - Authentication, rate limiting, error handling, security 🔧 Rails Integration - Generators, autoloading, middleware, Railtie 🛠️ Tools System - Callable functions with JSON Schema validation 📊 Resources System - Data exposure with URI templating 🔒 Security - DNS rebinding protection, CORS, token authentication ⚡ Real-time - Server Events (SSE) foundation (full implementation coming soon) 🎯 Developer-Friendly - Clean DSL, generators, testing support

Installation

Add to your Gemfile:

gem 'mcp_on_ruby'

Then run:

bundle install
rails generate mcp_on_ruby:install

Quick Start

1. Install and Configure

# Generate MCP server files
rails generate mcp_on_ruby:install

# Create a tool
rails generate mcp_on_ruby:tool UserManager --description "Manage application users"

# Create a resource  
rails generate mcp_on_ruby:resource UserStats --uri "users/{id}/stats" --template

2. Configure MCP Server

# config/initializers/mcp_on_ruby.rb
McpOnRuby.configure do |config|
  config.authentication_required = true
  config.authentication_token = ENV['MCP_AUTH_TOKEN']
  config.rate_limit_per_minute = 60
  config.allowed_origins = [/\.yourdomain\.com$/]
end

Rails.application.configure do
  config.mcp.enabled = true
  config.mcp.auto_register_tools = true
  config.mcp.auto_register_resources = true
end

3. Create Tools

# app/tools/user_manager_tool.rb
class UserManagerTool  3.0) - JSON Schema validation
- `rack` (~> 2.2) - HTTP transport layer
- `webrick` (~> 1.7) - HTTP server

## Contributing

1. Fork the repository
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Write tests for your changes
4. Ensure all tests pass (`bundle exec rspec`)
5. Commit your changes (`git commit -am 'Add some feature'`)
6. Push to the branch (`git push origin my-new-feature`)
7. Create a Pull Request

## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE.txt) file for details.

## 🙏 Acknowledgments

- The [Model Context Protocol](https://modelcontextprotocol.io) team at Anthropic for creating the specification
- The Ruby on Rails community for inspiration and conventions

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Made with ❤️ for the Ruby community

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [nagstler](https://github.com/nagstler)
- **Source:** [nagstler/mcp_on_ruby](https://github.com/nagstler/mcp_on_ruby)
- **License:** MIT

Install and usage instructions live in the source repository linked above.