# stick this in some kind of initializer code like config/environment.rb
APP_CONFIG = YAML.load_file("#{Rails.root}/config/app_config.yml")

# to make it environment specific
APP_CONFIG = YAML.load_file("#{Rails.root}/config/app_config.yml")[Rails.env]

# sample yaml :
<<-YAML # put this in config/app_config.yml

development:
  api_key: abcdefg

production:
  api_key: 1234567

YAML


# then you can access like this:
api_key = APP_CONFIG['api_key']