API Reference · Multitenancy · Rails

`Multitenancy` (module)

Method	Description
`Multitenancy.root`	Rails application root.
`Multitenancy.themes_root`	Path to `themes/` directory.
`Multitenancy.themes`	Array of `Theme` instances, one per `themes/<name>/` directory. Memoized.
`Multitenancy.reset!`	Clear memoized themes. Useful in tests.
`Multitenancy.config`	Global `Config` instance.

Themes are discovered lazily on first access to .themes — at Rails boot time they’re bootstrapped from the Railtie.

`Multitenancy::Config`

Attribute	Default	Purpose
`paths`	20+ standard Rails paths	Autoload directories to register per theme.

Default paths:

%w[
  app/controllers app/channels app/helpers app/services app/structs
  app/models app/mailers app/presenters app/decorators app/queries
  app/resources app/serializers app/transformers app/validators
  app/workers app/jobs app/notifications app/policies lib
]

Customize in an initializer:

Multitenancy.config.paths = %w[app/controllers app/models lib]

`Multitenancy::Theme`

Represents one theme directory.

Method	Description
`#name`	Theme name (basename of the directory).
`#path`	`Pathname` to the theme’s root.
`#namespace`	The dynamically-created `Themes::<Name>` module.
`#engine`	The dynamically-created `Themes::<Name>::Engine` class.
`#bootstrap(app)`	Creates the namespace, builds the engine, registers paths. Called by the Railtie.

You rarely construct Themes yourself — iterate Multitenancy.themes instead.

`Multitenancy::Controller`

ActiveSupport::Concern. Include in theme application controllers.

module Themes::Storefront
  class ApplicationController < ::ApplicationController
    include Multitenancy::Controller
  end
end

Configures:

prepend_view_path engine.root.join('app/views') — theme views win.
layout 'application' — use the theme’s layout.
before_action { engine.importmap_reloader&.execute_if_updated } — reload on JS changes in dev.

Private: `_prefixes`

Overridden to strip the theme namespace prefix from controller_path, so view lookup works naturally:

Themes::Storefront::HomeController → home/index  (not themes/storefront/home/index)

`Multitenancy::Stim`

Internal — the mixin included into each theme’s engine class. It configures:

isolate_namespace
called_from (for Rails::Engine#root)
paths["app/views"]
paths["app/assets"]
paths["config/locales"]
paths["app/javascript"]

You should not need to interact with it directly.

`Multitenancy::Integrations`

Namespace for optional-gem integrations. Each is a class with a .call(app) class method.

Integration	Guarded by	What it does
`Rails`	always	Bootstraps every theme (creates namespace, engine, path registration).
`FactoryBot`	`defined?(::FactoryBot)`	Adds each theme’s `spec/factories/` to FactoryBot’s paths.
`RSpec`	`defined?(::RSpec)`	Expands `rspec themes/<name>` to `themes/<name>/spec`; auto-discovers all theme specs by default.
`Minitest`	`defined?(::Rails::TestUnit::Runner)`	Same discovery behavior for Minitest.
`Importmap`	`defined?(::Importmap::Map)`	Creates per-theme importmaps; removes theme paths from main app’s importmap; wires dev reloader.
`TailwindCss`	`defined?(::Tailwindcss::Commands)`	Discovers theme Tailwind inputs, sets builds dirs, excludes raw inputs from Propshaft.

Load hook

An ActiveSupport.on_load(:multitenancy) hook fires after bootstrap completes:

ActiveSupport.on_load(:multitenancy) do |multitenancy|
  # multitenancy is the Multitenancy module
  # Multitenancy.themes is fully populated at this point
end

Generator

bin/rails generate multitenancy THEME_NAME [--importmap] [--tailwindcss]

See generator.md.

Rake tasks

multitenancy:tailwindcss:build
multitenancy:tailwindcss:watch

See rake-tasks.md.

Multitenancy (module)

Multitenancy::Config

Multitenancy::Theme

Multitenancy::Controller

Private: _prefixes

Multitenancy::Stim

Multitenancy::Integrations