app.py

from langchain.agents import AgentExecutor, AgentType, initialize_agent
from langchain.agents.structured_chat.prompt import SUFFIX
from langchain.chat_models import ChatOpenAI
from langchain.memory import ConversationBufferMemory
from tools import generate_image_tool

import chainlit as cl
from chainlit.action import Action
from chainlit.input_widget import Select, Switch, Slider


@cl.author_rename
def rename(orig_author):
    mapping = {
        "LLMChain": "Assistant",
    }
    return mapping.get(orig_author, orig_author)


@cl.cache
def get_memory():
    return ConversationBufferMemory(memory_key="chat_history")


@cl.on_chat_start
async def start():
    settings = await cl.ChatSettings(
        [
            Select(
                id="Model",
                label="OpenAI - Model",
                values=["gpt-3.5-turbo", "gpt-4-1106-preview"],
                initial_index=1,
            ),
            Switch(id="Streaming", label="OpenAI - Stream Tokens", initial=True),
            Slider(
                id="Temperature",
                label="OpenAI - Temperature",
                initial=0,
                min=0,
                max=2,
                step=0.1,
            ),
        ]
    ).send()
    await setup_agent(settings)


@cl.on_settings_update
async def setup_agent(settings):
    print("Setup agent with following settings: ", settings)

    llm = ChatOpenAI(
        temperature=settings["Temperature"],
        streaming=settings["Streaming"],
        model=settings["Model"],
    )
    memory = get_memory()
    _SUFFIX = "Chat history:\n{chat_history}\n\n" + SUFFIX

    agent = initialize_agent(
        llm=llm,
        tools=[generate_image_tool],
        agent=AgentType.STRUCTURED_CHAT_ZERO_SHOT_REACT_DESCRIPTION,
        memory=memory,
        agent_kwargs={
            "suffix": _SUFFIX,
            "input_variables": ["input", "agent_scratchpad", "chat_history"],
        },
    )
    cl.user_session.set("agent", agent)


@cl.on_message
async def main(message: cl.Message):
    agent = cl.user_session.get("agent")  # type: AgentExecutor
    cl.user_session.set("generated_image", None)

    # No async implementation in the Stability AI client, fallback to sync
    res = await cl.make_async(agent.run)(
        input=message.content, callbacks=[cl.LangchainCallbackHandler()]
    )

    elements = []
    actions = []

    generated_image_name = cl.user_session.get("generated_image")
    generated_image = cl.user_session.get(generated_image_name)
    if generated_image:
        elements = [
            cl.Image(
                content=generated_image,
                name=generated_image_name,
                display="inline",
            )
        ]

    await cl.Message(content=res, elements=elements, actions=actions).send()