# Rubygems Mcp Rb > Ruby gem providing RubyGems and Ruby version information via MCP (Model Context Protocol) server tools. Integrates with MCP-compatible clients like Cursor IDE, Claude Desktop, and other MCP-enabled tools. - **Type:** MCP server - **Install:** `agentstack add mcp-amkisko-rubygems-mcp-rb` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [amkisko](https://agentstack.voostack.com/s/amkisko) - **Installs:** 0 - **Category:** [Integrations](https://agentstack.voostack.com/c/integrations) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [amkisko](https://github.com/amkisko) - **Source:** https://github.com/amkisko/rubygems_mcp.rb - **Website:** https://rubygems.org/gems/rubygems_mcp ## Install ```sh agentstack add mcp-amkisko-rubygems-mcp-rb ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # rubygems_mcp [](https://badge.fury.io/rb/rubygems_mcp) [](https://github.com/amkisko/rubygems_mcp.rb/actions/workflows/test.yml) [](https://codecov.io/gh/amkisko/rubygems_mcp.rb) [](https://sonarcloud.io/summary/new_code?id=amkisko_rubygems_mcp.rb) Ruby gem providing RubyGems and Ruby version information via MCP (Model Context Protocol) server tools. Integrates with MCP-compatible clients like Cursor IDE, Claude Desktop, and other MCP-enabled tools. This gem accesses public RubyGems and Ruby version information, no authentication required. Sponsored by [Kisko Labs](https://www.kiskolabs.com). ## Requirements - **Ruby 3.1 or higher** (Ruby 3.0 and earlier are not supported) ## Quick Start ```bash gem install rubygems_mcp ``` ### Cursor IDE Configuration For Cursor IDE, create or update `.cursor/mcp.json` in your project: ```json { "mcpServers": { "rubygems": { "command": "gem", "args": ["exec", "rubygems_mcp"], "env": { "RUBY_VERSION": "3.4.7" } } } } ``` **Note**: Using `gem exec` ensures the correct Ruby version is used. If you're using a Ruby version manager like [mise](https://mise.jdx.dev/) or [rbenv](https://github.com/rbenv/rbenv), set the `RUBY_VERSION` environment variable to match your desired Ruby version. The `gem exec` command will automatically use the correct Ruby version based on your version manager configuration. ### Claude Desktop Configuration For Claude Desktop, edit the MCP configuration file: **macOS**: `~/Library/Application Support/Claude/claude_desktop_config.json` **Windows**: `%APPDATA%\Claude\claude_desktop_config.json` ```json { "mcpServers": { "rubygems": { "command": "gem", "args": ["exec", "rubygems_mcp"], "env": { "RUBY_VERSION": "3.4.7" } } } } ``` **Note**: After updating the configuration, restart Claude Desktop for changes to take effect. ### Testing with MCP Inspector You can test the MCP server using the [MCP Inspector](https://github.com/modelcontextprotocol/inspector) tool: ```bash # Run the MCP inspector with the server npx @modelcontextprotocol/inspector bundle exec rubygems_mcp ``` The inspector will: 1. Start a proxy server and open a browser interface 2. Connect to your MCP server via STDIO 3. Allow you to test all available tools interactively 4. Display request/response messages and any errors This is useful for: - Testing tool functionality before integrating with MCP clients - Debugging MCP protocol communication - Exploring available tools and their parameters ### Running the MCP Server manually After installation, you can start the MCP server immediately: ```bash # With bundler gem install rubygems_mcp && bundle exec rubygems_mcp # Or if installed globally rubygems_mcp ``` The server will start and communicate via STDIN/STDOUT using the MCP protocol. ## Features - **RubyGems API Client**: Full-featured client for RubyGems REST API with comprehensive endpoint coverage - **Ruby Version Information**: Fetch Ruby release information, changelogs, and maintenance status from ruby-lang.org - **MCP Server Integration**: Ready-to-use MCP server with 19 tools and 4 resources, compatible with Cursor IDE, Claude Desktop, and other MCP-enabled tools - **Pagination & Sorting**: Support for large result sets with customizable pagination and sorting options - **Caching**: In-memory caching with configurable TTL for improved performance - **Error Handling**: Graceful error handling with custom exceptions and response size limits - **No Authentication Required**: All endpoints are public, no API keys needed - **Comprehensive API Coverage**: Supports gem versions, latest versions, Ruby versions, gem search, gem information, reverse dependencies, download statistics, changelogs, and more ## Basic Usage ### API Client ```ruby require "rubygems_mcp" # Create client client = RubygemsMcp::Client.new # Get latest versions for multiple gems versions = client.get_latest_versions(["rails", "nokogiri", "rack"]) # => [ # { name: "rails", version: "7.1.0", release_date: #, license: "MIT" }, # { name: "nokogiri", version: "1.15.0", release_date: #, license: "MIT" }, # { name: "rack", version: "3.0.0", release_date: #, license: "MIT" } # ] # Get all versions for a gem versions = client.get_gem_versions("rails") # => [ # { version: "7.1.0", release_date: #, license: "MIT" }, # { version: "7.0.8", release_date: #, license: "MIT" }, # ... # ] # Get latest Ruby version ruby_version = client.get_latest_ruby_version # => { version: "3.3.0", release_date: # } # Get all Ruby versions ruby_versions = client.get_ruby_versions # => [ # { version: "3.3.0", release_date: # }, # { version: "3.2.0", release_date: # }, # ... # ] # Get gem information gem_info = client.get_gem_info("rails") # => { # name: "rails", # version: "7.1.0", # summary: "Full-stack web application framework.", # homepage: "https://rubyonrails.org", # source_code: "https://github.com/rails/rails", # documentation: "https://api.rubyonrails.org", # licenses: ["MIT"], # authors: ["David Heinemeier Hansson", ...] # } # Search for gems results = client.search_gems("rails") # => [ # { name: "rails", version: "7.1.0", info: "...", ... }, # { name: "rails_admin", version: "3.0.0", info: "...", ... }, # ... # ] # Get reverse dependencies reverse_deps = client.get_gem_reverse_dependencies("rails") # => ["rails_admin", "activeadmin", ...] # Get download statistics downloads = client.get_gem_version_downloads("rails", "7.1.0") # => { version_downloads: 123456, total_downloads: 987654321 } # Get Ruby maintenance status maintenance = client.get_ruby_maintenance_status # => [ # { version: "3.4", status: "normal maintenance", release_date: "2024-12-25", ... }, # { version: "3.3", status: "normal maintenance", ... }, # ... # ] # Get Ruby version changelog changelog = client.get_ruby_version_changelog("3.4.7") # => { version: "3.4.7", summary: "...", release_notes_url: "..." } # Get latest/recently updated gems latest = client.get_latest_gems(limit: 10) recently_updated = client.get_recently_updated_gems(limit: 10) ``` ## API Methods ### Gem Versions - `get_latest_versions(gem_names, fields: nil)` - Get latest versions for a list of gems with release dates and licenses. Supports GraphQL-like field selection. - `get_gem_versions(gem_name, limit: nil, offset: 0, sort: :version_desc, fields: nil)` - Get all versions for a single gem with release dates and licenses, sorted by version descending. Supports pagination, sorting, and field selection. ### Ruby Versions - `get_latest_ruby_version` - Get latest Ruby version with release date - `get_ruby_versions(limit: nil, offset: 0, sort: :version_desc)` - Get all Ruby versions with release dates, download URLs, and release notes URLs, sorted by version descending. Supports pagination and sorting. - `get_ruby_version_changelog(version)` - Get changelog summary for a specific Ruby version by fetching and parsing the release notes - `get_ruby_version_github_changelog(version)` - Get GitHub release changelog for a Ruby version from the ruby/ruby repository - `get_ruby_roadmap` - Get Ruby roadmap information from bugs.ruby-lang.org showing planned versions and their issues - `get_ruby_version_roadmap_details(version)` - Get detailed roadmap information for a specific Ruby version from bugs.ruby-lang.org, including issues and features planned for that version - `get_ruby_maintenance_status` - Get maintenance status for all Ruby versions including EOL dates and maintenance phases ### Gem Information - `get_gem_info(gem_name, fields: nil)` - Get detailed information about a gem (summary, homepage, source code, documentation, licenses, authors, dependencies, downloads). Supports GraphQL-like field selection. - `get_gem_version_info(gem_name, version, fields: nil)` - Get detailed information for a specific gem version using RubyGems API v2 (version-specific downloads, dependencies, SHA checksums, creation date, built date). Supports GraphQL-like field selection. - `get_gem_reverse_dependencies(gem_name)` - Get reverse dependencies - list of gems that depend on the specified gem - `get_gem_version_downloads(gem_name, version)` - Get download statistics for a specific gem version - `get_gem_changelog(gem_name, version: nil)` - Get changelog summary for a gem by fetching and parsing the changelog from its changelog_uri - `search_gems(query, limit: nil, offset: 0)` - Search for gems by name on RubyGems. Supports pagination. ### Gem Discovery - `get_latest_gems(limit: 30)` - Get latest gems - most recently added gems to RubyGems.org - `get_recently_updated_gems(limit: 30)` - Get recently updated gems - most recently updated gem versions - `get_news_releases(page: 1)` - Get news releases - all new gem releases from RubyGems.org with pagination (fetches from `/news?page=N`) - `get_popular_releases(page: 1)` - Get popular releases - popular new gem releases from RubyGems.org with pagination (fetches from `/releases/popular?page=N`) ## MCP Server Integration This gem includes a ready-to-use MCP server that can be run directly: ```bash # After installing the gem bundle exec rubygems_mcp ``` Or if installed globally: ```bash gem install rubygems_mcp rubygems_mcp ``` The server will communicate via STDIN/STDOUT using the MCP protocol. Configure it in your MCP client (e.g., Cursor IDE, Claude Desktop, or other MCP-enabled tools). ## MCP Tools The MCP server provides the following tools: 1. **get_latest_versions** - Get latest versions for a list of gems with release dates and licenses. Supports GraphQL-like field selection. - Parameters: `gem_names` (array of strings), `fields` (optional array of strings) 2. **get_gem_versions** - Get all versions for a single gem with release dates and licenses, sorted by version descending. Supports GraphQL-like field selection. - Parameters: `gem_name` (string), `limit` (optional integer), `offset` (optional integer), `sort` (optional string: "version_desc", "version_asc", "date_desc", "date_asc"), `fields` (optional array of strings) 3. **get_latest_ruby_version** - Get latest Ruby version with release date - Parameters: none 4. **get_ruby_versions** - Get all Ruby versions with release dates, download URLs, and release notes URLs, sorted by version descending - Parameters: `limit` (optional integer), `offset` (optional integer), `sort` (optional string: "version_desc", "version_asc", "date_desc", "date_asc") 5. **get_ruby_version_changelog** - Get changelog summary for a specific Ruby version by fetching and parsing the release notes - Parameters: `version` (string, e.g., "3.4.7") 6. **get_gem_info** - Get detailed information about a gem (summary, homepage, source code, documentation, licenses, authors, dependencies, downloads). Supports GraphQL-like field selection. - Parameters: `gem_name` (string), `fields` (optional array of strings) 7. **get_gem_version_info** - Get detailed information for a specific gem version using RubyGems API v2 (version-specific downloads, dependencies, SHA checksums, creation date, built date). Supports GraphQL-like field selection. - Parameters: `gem_name` (string), `version` (string, e.g., "0.1.0" or "1.15.0-x86_64-linux"), `fields` (optional array of strings) 8. **get_gem_reverse_dependencies** - Get reverse dependencies - list of gems that depend on the specified gem - Parameters: `gem_name` (string) 9. **get_gem_version_downloads** - Get download statistics for a specific gem version - Parameters: `gem_name` (string), `version` (string) 10. **get_latest_gems** - Get latest gems - most recently added gems to RubyGems.org - Parameters: `limit` (optional integer, default: 30, max: 50) 11. **get_recently_updated_gems** - Get recently updated gems - most recently updated gem versions - Parameters: `limit` (optional integer, default: 30, max: 50) 12. **get_gem_changelog** - Get changelog summary for a gem by fetching and parsing the changelog from its changelog_uri - Parameters: `gem_name` (string), `version` (optional string, uses latest if not provided) 13. **search_gems** - Search for gems by name on RubyGems - Parameters: `query` (string) 14. **get_ruby_roadmap** - Get Ruby roadmap information from bugs.ruby-lang.org showing planned versions and their issues - Parameters: none 15. **get_ruby_version_roadmap_details** - Get detailed roadmap information for a specific Ruby version from bugs.ruby-lang.org, including issues and features planned for that version - Parameters: `version` (string, e.g., "3.4", "4.0") 16. **get_ruby_version_github_changelog** - Get GitHub release changelog for a Ruby version from the ruby/ruby repository - Parameters: `version` (string, e.g., "3.4.7", "3.4.0") 17. **get_news_releases** - Get news releases - all new gem releases from RubyGems.org with pagination - Parameters: `page` (optional integer, default: 1) - Page number (1-based) - Fetches from: `https://rubygems.org/news?page=N` 18. **get_popular_releases** - Get popular releases - popular new gem releases from RubyGems.org with pagination - Parameters: `page` (optional integer, default: 1) - Page number (1-based) - Fetches from: `https://rubygems.org/releases/popular?page=N` ## MCP Resources The MCP server provides the following resources: 1. **rubygems://popular** - A curated list of popular Ruby gems with their latest versions - Resource name: "Popular Ruby Gems" - MIME type: application/json 2. **rubygems://ruby/compatibility** - Information about Ruby version compatibility and release dates - Resource name: "Ruby Version Compatibility" - MIME type: application/json 3. **rubygems://ruby/maintenance** - Detailed maintenance status for all Ruby versions including EOL dates and maintenance phases - Resource name: "Ruby Maintenance Status" - MIME type: application/json 4. **rubygems://ruby/latest** - The latest stable Ruby version with release date - Resource name: "Latest Ruby Version" - MIME type: application/json ## Error Handling The client handles errors gracefully: - Returns empty arrays for failed requests - Returns empty hashes for failed gem info requests - Handles network errors and JSON parsing errors ## Development ```bash # Install dependencies bundle install # Run tests bundle exec rspec # Run tests across multiple Ruby versions bundle exec appraisal install bundle exec appraisal rspec # Run linting bundle exec standardrb --fix # Validate RBS type signatures bundle exec rbs validate ``` ## Contributing Bug reports and pull requests are welcome on GitHub at https://github.com/amkisko/rubygems_mcp.rb. Contribution policy: - New features are not necessarily added to the gem - Pull request should have test coverage for affected parts - Pull request should have changelog entry Review policy: - It might take up to 2 calendar weeks to review and merge critical fixes - It might take up to 6 calendar months to review and merge pull request - It might take up to 1 calendar year to review an issue For more information, see [CONTRIBUTING.md](CONTRIBUTING.md). ## Security If you discover a security vulnerability, please report it responsibly. See [SECURITY.md](SECURITY.md) for details. ## License The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT). ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [amkisko](https://github.com/amkisko) - **Source:** [amkisko/rubygems_mcp.rb](https://github.com/amkisko/rubygems_mcp.rb) - **License:** MIT - **Homepage:** https://rubygems.org/gems/rubygems_mcp Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-amkisko-rubygems-mcp-rb - Seller: https://agentstack.voostack.com/s/amkisko - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.