Unofficial ChatGPT API Wrapper Ruby

chat_gpt_service.rb

# The ChatGptService class provides an easy way to integrate with the OpenAI ChatGPT API.
# It allows you to send and receive messages in a conversation thread, and reset the thread
# if necessary.
#
# Example usage:
#   chat_gpt_service = ChatGptService.new(BEARER_TOKEN)
#   response = chat_gpt_service.chat("Hello, how are you?")
#   puts response
#   # => {"message"=>
#   #     {"id"=>"8e78691a-1fde-4bd5-ad68-46b23ea65d8f",
#   #      "role"=>"assistant",
#   #      "user"=>nil,
#   #      "create_time"=>nil,
#   #      "update_time"=>nil,
#   #      "content"=>
#   #       {"content_type"=>"text",
#   #        "parts"=>
#   #         ["Hello! How can I help you today? Is there something on your mind that you would like to talk about or ask about? I'm here to assist you with any questions you may have, so feel free to ask away."]},
#   #      "end_turn"=>nil,
#   #      "weight"=>1.0,
#   #      "metadata"=>{},
#   #      "recipient"=>"all"},
#   #    "conversation_id"=>"edbf3a3b-7d3f-4bed-a437-a09d69a93c9c",
#   #    "error"=>nil}
#
#   # reset the conversation thread
#   chat_gpt_service.reset_thread
#
require "json"
require "net/https"
require "securerandom"

class ChatGptService
  attr_reader :conversation_id

  def initialize(bearer_token)
    @bearer_token = bearer_token
    @conversation_id = nil
  end

  def chat(message)
    payload = {
      action: "next",
      messages: [
        {
          id: SecureRandom.uuid,
          role: "user",
          content: {content_type: "text", parts: [message]}
        }
      ],
      parent_message_id: @parent_message_id || SecureRandom.uuid,
      model: "text-davinci-002-render"
    }

    payload[:conversation_id] = conversation_id if conversation_id

    response = post(
      "https://chat.openai.com/backend-api/conversation",
      payload,
      @bearer_token
    )

    response = JSON.parse(response.compact.last(2).first)

    @parent_message_id = response.dig("message", "id")
    @conversation_id = response.dig("conversation_id")

    response
  end

  def reset_thread
    @conversation_id = nil
  end

  private

  def post(url, data, bearer_token)
    uri = URI(url)
    https = Net::HTTP.new(uri.host, uri.port)
    https.use_ssl = true

    request = Net::HTTP::Post.new(uri.path, "Content-Type" => "application/json")
    request["Authorization"] = "Bearer #{bearer_token}"
    request.body = data.to_json

    response = https.request(request)
    response.body
    response.body.lines.map { |line| line[sse_substring..] }.compact
  end

  def sse_substring
    "data: ".length
  end
end