In Rails projects, config/initializers/config.rb can be used to configure this gem, but the Railtie performs the actual first load of the settings files. The Railtie doesn't offer a way to specify additional settings sources (for example, multiple YAML files).

It's possible to specify additional settings files today if users use a separate initializer, but this isn't always convenient because it essentially means that settings are loaded twice (and both times must satisfy the configured schema or contract) and because the initializer runs much later in the Rails boot process (so it's not available when evaluating some files like config/environments/production.rb)

Related:

• Added config.prepend_sources option to Config.setup #142
• Settings are loaded before setup block executed #244
• Integration with encrypted Rails credentials #68 (comment)