OpenGemdocs

This gem makes accessing ruby gem documentation easy for users with a CLI tool and AI agents with a MCP server.

There are three documentation sources this gem supports.

1. local gems served with the yard gem via yard server --gems or yard server --gemfile accessible at http://localhost:8808.
2. https://gemdocs.org - a good ruby gem documentation host
3. Locally compiled documentation for gems defined in your Gemfile.lock using the document-bundle command. The MCP server uses this.

• If ran from a directory with a Gemfile.lock, it will open the documentation for the version specified in Gemfile.lock. When using the online source, you can specify --latest or --version options.
• Defaults to open the latest version of the documentation if not --local or a Gemfile.lock is not found in the current directory.
• Can specify a version of the docs to view
• When ran with --local, it will either serve docs for all gems you have installed or the versions specified in your Gemfile.

Install the gem and add to the application's Gemfile by executing:

bundle add open_gemdocs --group development

If bundler is not being used to manage dependencies, install the gem by executing:

gem install open_gemdocs

Currently, this only works on Macs because of the open command. It opens the documentation for a gem in your default web browser.

To see the available options.

open-gem-docs --help

If you are in a directory with a Gemfile.lock, it will open the documentation for the version of the gem you are using unless you specify --latest or --version options.

If you are not in a directory with a Gemfile.lock, it will open the latest version of the documentation.

open-gem-docs rspec

(Assuming you are in a directory with a Gemfile.lock, it will open the rspec docs for the version you are using.)

Open a specific version (regardless of what is in your Gemfile.lock)

open-gem-docs -v 3.12.0 rspec

Open the latest version of the documentation

open-gem-docs --latest rspec

To use a local documentation server. Run the following command from a directory where Gemfile.lock exists. This will serves the documentation for your currently installed gems.

open-gem-docs --local

You can also jump directly to a local doc gem page:

open-gem-docs --local rspec

If you prefer the --local option to be the default, you can use the open-local-docs command instead of open-gem-docs. Example using the open-local-docs command:

open-local-docs rspec

Pre-processing the gem docs makes lookups faster.

Change directory to a repository with a Gemfile.lock and run the following command:

document-bundle

The MCP server provides the following tools:

• search_gems - Search for installed Ruby gems by name
• get_gem_info - Get detailed information about a specific gem
• start_yard_server - Start the Yard documentation server
• stop_yard_server - Stop the Yard documentation server
• get_yard_server_status - Check if the Yard server is running
• get_gem_documentation_url - Get the local documentation URL for a gem
• fetch_gem_docs - Fetch documentation content from the Yard server

claude mcp add open-gem-docs -- open-gem-docs-mcp-stdio

• Test the MCP server with different AI agents
• Support agents launched in directories that do not have a Gemfile.lock
• Experiment with providing direct gem source files to see if that is more beneficial for the AI agent.

• The MCP server only supports Mac and linux platforms currently due to bash commands it uses.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/mrinterweb/open_gemdocs.

The gem is available as open source under the terms of the MIT License.