crewai_panel.py

##
## pip install crewai==0.28.8 panel==1.4.0
##

from crewai import Crew, Process, Agent, Task
from langchain_openai import ChatOpenAI

from langchain_core.callbacks import BaseCallbackHandler
from typing import TYPE_CHECKING, Any, Dict, Optional

import panel as pn 
pn.extension(design="material")

import threading

from crewai.agents import CrewAgentExecutor
import time 

def custom_ask_human_input(self, final_answer: dict) -> str:
      
      global user_input

      prompt = self._i18n.slice("getting_input").format(final_answer=final_answer)

      chat_interface.send(prompt, user="assistant", respond=False)

      while user_input == None:
          time.sleep(1)  

      human_comments = user_input
      user_input = None

      return human_comments


CrewAgentExecutor._ask_human_input = custom_ask_human_input

user_input = None
initiate_chat_task_created = False

def initiate_chat(message):

    global initiate_chat_task_created
    # Indicate that the task has been created
    initiate_chat_task_created = True

    StartCrew(message)

def callback(contents: str, user: str, instance: pn.chat.ChatInterface):
    
    global initiate_chat_task_created
    global user_input

    if not initiate_chat_task_created:
        thread = threading.Thread(target=initiate_chat, args=(contents,))
        thread.start()

    else:
        user_input = contents

avators = {"Writer":"https://cdn-icons-png.flaticon.com/512/320/320336.png",
            "Reviewer":"https://cdn-icons-png.freepik.com/512/9408/9408201.png"}

class MyCustomHandler(BaseCallbackHandler):

    
    def __init__(self, agent_name: str) -> None:
        self.agent_name = agent_name

    def on_chain_start(
        self, serialized: Dict[str, Any], inputs: Dict[str, Any], **kwargs: Any
    ) -> None:
        """Print out that we are entering a chain."""

        chat_interface.send(inputs['input'], user="assistant", respond=False)

    def on_chain_end(self, outputs: Dict[str, Any], **kwargs: Any) -> None:
        """Print out that we finished a chain."""
    
        chat_interface.send(outputs['output'], user=self.agent_name, avatar=avators[self.agent_name], respond=False)

llm = ChatOpenAI(model="gpt-3.5-turbo-0125")

writer = Agent(

    role='Blog Post Writer',
    backstory='''You are a blog post writer who is capable of writing a travel blog.
                      You generate one iteration of an article once at a time.
                      You never provide review comments.
                      You are open to reviewer's comments and willing to iterate its article based on these comments.
                      ''',
    goal="Write and iterate a decent blog post.",
    llm=llm,
    callbacks=[MyCustomHandler("Writer")],
)
reviewer = Agent(
    role='Blog Post Reviewer',
    backstory='''You are a professional article reviewer and very helpful for improving articles.
                 You review articles and give change recommendations to make the article more aligned with user requests.
                 You will give review comments upon reading entire article, so you will not generate anything when the article is not completely delivered. 
                  You never generate blogs by itself.''',
    goal="list builtins about what need to be improved of a specific blog post. Do not give comments on a summary or abstract of an article",
    llm=llm,
    callbacks=[MyCustomHandler("Reviewer")],
)

def StartCrew(prompt):

    task1 = Task(
      description=f"""Write a blog post of {prompt}. """,
      agent=writer,
      expected_output="an article under 100 words."
    )

    task2 = Task(
      description=("list review comments for improvement from the entire content of blog post to make it more viral on social media."
                    "Make sure to check with a human if your comment is good before finalizing your answer."
                ),
      agent=reviewer,
      expected_output="Builtin points about where need to be improved.",
      human_input=True,
    )
    # Establishing the crew with a hierarchical process
    project_crew = Crew(
        tasks=[task1, task2],  # Tasks to be delegated and executed under the manager's supervision
        agents=[writer, reviewer],
        manager_llm=llm,
        process=Process.hierarchical  # Specifies the hierarchical management approach
    )

    result = project_crew.kickoff()

    chat_interface.send("## Final Result\n"+result, user="assistant", respond=False)


chat_interface = pn.chat.ChatInterface(callback=callback)
chat_interface.send("Send a message!", user="System", respond=False)
chat_interface.servable()