RubyLLM::MCP

RubyLLM::MCP is a Ruby framework designed to provide direct integration with Model Context Protocol (MCP) servers, allowing developers to incorporate MCP tools, resources, and prompts into RubyLLM chat workflows. It is aimed at Ruby and Rails developers seeking to build chat-based or automation solutions that leverage the MCP specification, with support for the stable MCP spec 2025-06-18 and optional draft spec 2026-01-26. The library offers a Ruby-first API that simplifies the use of MCP features within Ruby applications and background jobs.

Key features include the ability to convert MCP tools into RubyLLM-compatible tools, work with resources and resource templates in chat contexts, and execute server prompts with typed arguments. The platform supports multiple transport types such as :stdio, :streamable, and :sse, and provides client capabilities like sampling, roots, progress tracking, and elicitation. Built-in notification and response handlers enable real-time and interactive workflows.

1 support with PKCE, dynamic registration, discovery, and automatic token refresh. There are dedicated setup paths for per-user OAuth flows in Rails applications and browser-based OAuth for CLI tools. The framework supports global and per-client extension negotiation, including MCP Apps, and allows management of multiple MCP servers within a single workflow. Users can control protocol versions with stable defaults and explicit draft opt-in.

Installation is available via RubyGems by adding the "ruby_llm-mcp" gem, with optional official SDK adapter support through the "mcp" gem. For Rails integration, generator commands are provided to streamline setup, including per-user OAuth flows. The tool is released under the MIT License, making it open source and freely available for modification and distribution. RubyLLM::MCP is maintained by Patrick Vice.