> For the complete documentation index, see [llms.txt](https://docs.consuldemocracy.org/tech_docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.consuldemocracy.org/tech_docs/english-v2.2/customization/ruby.md).

# Other Ruby classes (GraphQL, lib, mailers, builders)

Other than models, controllers and components, there are a few other folders containing Ruby code:

* `app/form_builders/`
* `app/graphql/`
* `app/lib/`
* `app/mailers/`

The files in these folders can be customized like any other Ruby file (see [customizing models](/tech_docs/english-v2.2/customization/models.md) for more information).

For example, in order to customize the `app/form_builders/consul_form_builder.rb` file, create a file `app/form_builders/custom/consul_form_builder.rb` with the following content:

```ruby
load Rails.root.join("app", "form_builders", "consul_form_builder.rb")

class ConsulFormBuilder
  # Your custom logic here
end
```

Or, in order to customize the `app/lib/remote_translations/caller.rb` file, create a file `app/lib/custom/remote_translations/caller.rb` with the following content:

```ruby
load Rails.root.join("app", "lib", "remote_translations", "caller.rb")

class RemoteTranslations::Caller
  # Your custom logic here
end
```