Configuration

Configure the gem in an initializer:

# config/initializers/katalyst_content.rb
Katalyst::Content.configure do |config|
  config.items          = %w[Katalyst::Content::Section Content::Spacer]
  config.themes         = %w[light dark]
  config.base_controller = "Admin::BaseController"
end

Items and presentation

items — the item types available in the editor’s new-item dialog. Defaults to the built-in types. See custom items.
themes — theme names offered on items (default light dark). default_theme sets the theme assumed when none is selected.
heading_styles — heading style options (default none default).

Images

image_mime_types — content types accepted by image attachments (default PNG, GIF, JPEG, WebP).
max_image_size — maximum image size in megabytes (default 20).

These are conventions for your item validations rather than enforced globally — built-in items validate against them, and custom items can too; they’re available as config in the class body:

validates :image,
          content_type: config.image_mime_types,
          size:         { less_than: config.max_image_size.megabytes }

Editor integration

base_controller — the class name the engine’s editor controllers inherit from (default "ApplicationController"). This is how the editor’s item endpoints pick up your application’s authentication and authorization: point it at your admin base controller. If you leave the default, item editing is only as protected as your ApplicationController — for an admin-only editor that almost certainly isn’t what you want.
errors_component — the ViewComponent used to render validation errors in the editor (default "Katalyst::Content::Editor::ErrorsComponent"). Override to customise error presentation.

Table sanitisation

Pasted table content is sanitised before rendering:

table_sanitizer_allowed_tags / table_sanitizer_allowed_attributes — the allowlists applied to table HTML.

For deeper customisation, Katalyst::Content::TableHelper exposes the sanitizer itself:

Katalyst::Content::TableHelper.sanitizer = MySanitizer.new
Katalyst::Content::TableHelper.scrubber  = MyScrubber.new