yjacquin/fast-mcp

This system is a Ruby gem that implements the Model Context Protocol (MCP) for server-side applications, enabling the creation of MCP servers with tools and resources. It provides middleware for integrating these servers into Rack-based frameworks like Rails, supporting both standard and authenticated transports via Server-Sent Events. The library includes generators for scaffolding, schema validation, and comprehensive testing utilities to ensure compliance and security.

Introduces a new \fast\_mcp:install\ generator that scaffolds a Rails application for Model Context Protocol (MCP) support. Running the generator creates a \config/initializers/fast\_mcp.rb\ file with middleware configuration (including default routes for SSE and messages, and security settings like \localhost\_only\), along with base classes \ApplicationTool\ and \ApplicationResource\ for inheritance, and sample implementations to demonstrate usage.

lib/generators · high confidence

The \examples/rails-demo-app\ directory now contains a complete, production-ready Rails 8.0 application scaffold. This includes a Dockerfile for containerized deployment, Kamal configuration files for orchestration, and a GitHub Actions CI workflow that runs security scans (Brakeman, Importmap audit) and tests. The application is configured with SQLite for development and production, Solid Cache, Solid Cable, and Solid Queue for background jobs, and uses Thruster as the HTTP server. It also features a basic MCP (Model Context Protocol) integration via a \User\ model hook and a \SampleResource\.

examples/rails-demo-app · high confidence

Establishes the foundational structure for the Fast MCP Ruby gem, including the initial release (v0.1.0) and core library code. This change introduces essential development and quality tools: a \.rubocop.yml\ configuration for code style enforcement (targeting Ruby 3.0), an \.rspec\ file for test formatting, and a \.gitignore\ to exclude build artifacts. It also adds standard documentation files such as \CONTRIBUTING.md\, \CHANGELOG.md\, and an updated \README.md\ that describes the library's features, including tool and resource APIs, multiple transport options, and Rails integration.

(repo-wide) · high confidence

This change introduces the FastMcp library (v1.6.0), providing a Ruby implementation of the Model Context Protocol (MCP). It includes a \Server\ class for handling JSON-RPC requests, support for registering and filtering tools and resources, and a dedicated \Railtie\ for automatic discovery of tools and resources in Rails applications. The library also features a custom \Logger\ for transport-aware logging and extends Dry::Schema to support schema metadata like descriptions and hidden properties.

lib/mcp · high confidence

This change introduces the FastMcp library, a Ruby implementation of the Model Context Protocol (MCP) for server-side applications. It provides a core module for managing MCP servers, tools, and resources, along with convenience methods to integrate the server into Rack-based applications (including Rails) via middleware. The library supports configurable routes for SSE and messages, authentication options, and DNS rebinding protection.

lib · high confidence

The library now includes a new \RackTransport\ class that allows the MCP server to be mounted as middleware in any Rack-compatible web framework, supporting configurable routes for Server-Sent Events (SSE) and message handling, along with security features like DNS rebinding protection and localhost-only binding by default. Additionally, an \AuthenticatedRackTransport\ subclass is provided to enforce token-based authentication on incoming requests, allowing administrators to specify custom auth headers and exempt specific paths from authentication checks.

lib/mcp/transports · high confidence

Added several Ruby example scripts demonstrating how to use the FastMcp library. These include a basic Rack middleware setup, an authenticated Rack middleware variant, a server using stdio transport with file-backed resources and tools, and a comprehensive tool definition guide. The examples also introduce dynamic tool and resource filtering based on user roles (public, user, admin) and demonstrate advanced argument validation using Dry::Schema, including nested objects, arrays, and optional fields.

examples · high confidence

A new script, script/verify\_gemspec.rb, has been added to verify that the gemspec loads correctly, aiding CI processes in catching issues early. Additionally, a .bundle/config file was introduced to configure Bundler to include the 'examples' directory during dependency resolution.

.bundle, script · high confidence

Added comprehensive RSpec tests covering the FastMcp server, tools, resources, and Rack-based transports. The new test suite validates core server behaviors such as handling ping, initialize, and notification requests, as well as tool registration, execution, and filtering. It also verifies resource management including templated resources and dynamic content, and ensures transport layers correctly handle authentication, SSE client management, and request filtering.

spec · high confidence

This change introduces the initial version of the fast-mcp Ruby gem (v1.6.0) and a new Rails 8.0.2 demo application. The gem provides a Model Context Protocol implementation with runtime dependencies on addressable, dry-schema, json, mime-types, and rack (relaxed to support versions 2.0 through 3.x). The accompanying Rails demo app showcases integration with the gem and utilizes modern Rails tooling including Propshaft, Solid Cache/Queue/Cable, and Kamal for deployment.

(dependencies) · high confidence

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

• First survey — no prior run to compare against. CAI 68.

• Code Health 99
• Architecture 94
• Maturity 56
• Readiness 77
• Security 68
• Domain Modelling 100

• 73 commits — 63 feature/other, 10 fixes

• (root) — 32 commits
• lib/mcp — 23 commits
• lib/fast_mcp.rb — 4 commits
• .github/workflows — 3 commits
• examples/rails-demo-app — 3 commits
• docs/sinatra_integration.md — 2 commits
• spec/mcp — 2 commits
• .github/FUNDING.yml — 1 commit
• docs/configuring_mcp_clients.md — 1 commit
• docs/tools.md — 1 commit
• lib/generators — 1 commit

• fix: :bug: change empty string to empty array (#61)
• fix: Fix #30 by wrapping nil response with send_response method (#31)
• fix: Fix authenticated rack middleware (#35)
• fix: Fix missing commas for params hash (#121)
• fix: fix rubocop linting issues
• fix: fix: undefined local variable or method "headers" (#87)
• fix: 📚 Fix README example
• fix: 🔧 Fix notifications/initialized response (#51)
• fix: 🔨 Fix specs
• fix: 🤖 Linter fixes
• change: Add Changelog changes and bump gem version (#92)
• change: Add Discord Server link
• change: Add Metadata to Tool call results (#69)
• change: Add Resource templates (#84)
• change: Add check against Rails env for localhost_only binding (#45)
• change: Add configuration docs for Zed (#76)
• change: Add items to array (#55)
• change: Add on_error_result server hook (#129)
• change: Add thread safety to RackTransport sse_clients (#82)
• change: Add tool annotations support (#96)
• …and 53 more

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

yjacquin/fast-mcp was measured the same way every project in this corpus was: the same rubric, at a pinned commit, with the result published in full. Point a surveyor at a repository you know and see whether you agree with it.