This Ruby SDK implements the Model Context Protocol (MCP), enabling developers to build clients and servers for AI-powered applications. It facilitates communication for tools, prompts, and resources, offering a structured way to integrate LLM capabilities into Ruby applications.

How It Works

The SDK provides an MCP::Server class that acts as the central hub for handling JSON-RPC requests and responses according to the MCP specification. It supports various transports like HTTP (with Server-Sent Events for notifications) and stdio. Key functionalities include managing tool and prompt registration, invoking tools, retrieving resources, and sending real-time notifications when lists of tools, prompts, or resources change.

Quick Start & Requirements

• Install via Bundler: gem 'mcp' and bundle install.
• Install directly: gem install mcp.
• Usage examples for HTTP and stdio transports are provided in the README.

Highlighted Details

• Implements JSON-RPC 2.0, initialization, capability negotiation, tool/prompt/resource management, and notifications.
• Supports HTTP (SSE) and stdio transports.
• Allows defining tools and prompts as classes or via define methods, with support for input schemas and annotations.
• Includes configurable exception reporting and instrumentation callbacks.

Maintenance & Community

Maintained in collaboration with Shopify. Releases are automated via GitHub Actions upon merging PRs that update the version in lib/mcp/version.rb.

Licensing & Compatibility

The README does not explicitly state a license. Compatibility for commercial use or closed-source linking is not specified.

Limitations & Caveats

Log level control and resource subscriptions are listed as unsupported features to be implemented in future versions.