ActiveROM ;)

active-rom.rb

require 'rom-sql'
require 'virtus'

module ActiveRecord
  class Base
    def self.inherited(klass)
      rel_class = Class.new(ROM::Relation[:sql]) {
        base_name Inflecto.tableize(klass.name).to_sym
      }
      dataset = repository.dataset(rel_class.base_name)
      attributes = dataset.columns
      mod = Module.new {
        include Virtus.module

        attributes.each { |name| attribute(name) }
      }
      klass.send(:include, mod)

      klass.class_eval do
        class << self
          attr_accessor :relation, :mapper
        end
      end

      klass.mapper = Class.new(ROM::Mapper) {
        model klass
        attributes.each { |name| attribute(name) }
      }.build

      klass.relation = rel_class.new(dataset)
      klass.send(:include, Equalizer.new(*attributes))

      super
    end

    def self.rom
      ROM.env
    end

    def self.repository
      rom.repositories[:default]
    end

    def self.find(id)
      map(relation.where(id: id)).first
    end

    def self.first
      map(relation.limit(1)).first
    end

    def self.create(tuple)
      find(relation.insert(tuple))
    end

    def self.map(relation)
      mapper.process(relation)
    end
  end
end

setup = ROM.setup(:sql, 'postgres://localhost/rom')

setup.default.connection.drop_table?(:users)
setup.default.connection.create_table(:users) do
  primary_key :id
  String :name
  String :email
end

ROM.finalize

class User < ActiveRecord::Base
end

puts User.create(name: 'Piotr', email: 'piotr@example.com').inspect
# => #<User id=1 name="Piotr" email="piotr@example.com">

puts User.first.inspect
# => #<User id=1 name="Piotr" email="piotr@example.com">
#
puts User.find(1).inspect
# => #<User id=1 name="Piotr" email="piotr@example.com">