This simple controller mixin allows you to lose the "_attributes" suffix when POST/PUTting data to your API, while maintaining the same nested attribute model behaviour. Simply replace params[:posts] with attributify(:posts) in your controllers. The old behaviour should still work.

attributify.rb

module Attributify

  def attributify(key, unprocessed=params[key])

    if unprocessed.is_a? Hash
      specific_params = {}
      unprocessed.each do |k,v|
        if (v.is_a?(Hash) && !k.to_s.match(/_attributes$/)) or (v.is_a?(Array) && !k.to_s.match(/_ids$/))
          # Nested, so suffix with '_attributes'
          specific_params["#{k}_attributes".to_sym] = attributify(key, v)
        else
          specific_params[k] = v
        end
      end
      return specific_params
    elsif unprocessed.is_a? Array
      unprocessed.map do |p| attributify(key, p) end
    else
      unprocessed
    end
  end

end