ActiveModel validation errors make great feedback for LLMs.

chat_block.rb

class ChatBlock
  DEFAULT_RETRIES = 2

  attr_reader :chat, :retries

  def self.wrap(chat, retries: DEFAULT_RETRIES, &block)
    new(chat, retries:).execute(&block)
  end

  def initialize(chat, retries: DEFAULT_RETRIES)
    @chat = chat
    @retries = retries
  end

  def execute(&block)
    (retries + 1).times do
      return ActiveRecord::Base.transaction(&block)
    rescue StandardError => e
      chat.add_message(
        role: "user",
        content: "Error: #{e.message}"
      )
    end
  end
end

example.rb

class Person
  include ActiveModel::Validations
  attr_accessor :name
  validates :name, length: {maximum: 3}
end

chat = RubyLLM.chat
person = Person.new

ChatBlock.wrap(chat) do
  person.name = chat.ask("Give me a name").content
  person.validate!
end

chat.messages.each { |m| puts "#{m.role}: #{m.content}"}

# user: Give me a name
#
# assistant: Sure! Here are a few options in different styles. If none of
# these fit what you’re looking for, just tell me the vibe (classic, unique,
# gender-neutral, cultural background, etc.) and I can tailor more
# suggestions.
# 
# Classic: Eleanor
# Modern: Jaxon
# Gender-neutral: River
# Literary: Atticus
# Mythological: Aria
# Short & punchy: Leo
#
# user: Error: Validation failed: Name is too long (maximum is 3 characters)
#
# user: Give me a name
#
# assistant: Kai