ruby-lsp connects the Ruby language server to Claude Code, giving it code intelligence and diagnostics for rb, .rake, .gemspec, .ru, .erb files. The plugin only wires up the server; the server binary must be installed separately.
What it does
Where Ruby LSP runs and what it adds, from its documentation
Registers the ruby-lsp language server (command: ruby-lsp) via the marketplace lspServers entry
Maps file extensions to the language: .rb, ..rake, ..gemspec, ..ru, ..erb
Gives Claude Code code intelligence and diagnostics for Ruby projects
When to use it
Good fit
Working in a Ruby codebase where Claude Code should use real language-server analysis
Wanting diagnostics and navigation from ruby-lsp without leaving Claude Code
Not for
Projects in other languages (it only maps the extensions listed)
Setups where you cannot install the ruby-lsp binary on PATH
How to install Ruby LSP
You need: Claude Code; ruby-lsp binary on PATH; Ruby 3.0 or later
Install the language server binary first (the plugin does not bundle it):
gem install ruby-lsp
Or add gem 'ruby-lsp', group: :development to your Gemfile and run bundle install
Install the plugin: /plugin install ruby-lsp@claude-plugins-official
Permissions and security
What it can access
Launches the ruby-lsp process locally and reads the project files it analyzes
Security notes from the maintainers
Marketplace README: make sure you trust a plugin before installing, updating, or using it
Review the source before granting an agent access to credentials or production systems. We document what the maintainers state; we do not audit code.
Limitations
Requires the language server to be installed separately; the plugin does not install it
