plugin_basic_setup

🧩 Create a Custom Rails Plugin

Rails plugins are gems that hook into a Rails app via Railties. To start, generate a new plugin and add an initializer in the gem’s lib folder. This allows you to run code during the host app’s boot process.

$ rails plugin new greeting_plugin

# greeting_plugin/lib/greeting_plugin.rb
module GreetingPlugin
  class Railtie < ::Rails::Railtie
    initializer "greeting_plugin.configure" do
      puts "GreetingPlugin initialized!"
    end
  end
end

In your host app’s Gemfile:

gem "greeting_plugin", path: "../greeting_plugin"

Run bundle install to load your plugin into the Rails application.