How to create a chat app from AI agent using Langchain.

Prerequisites

1. Install langchain package

pip install langchain

2. et OPENAI_KEY in .env

OPENAI_KEY=xxxxxxxx

Code

Python

import os
import morph
from morph import MorphGlobalContext
from morph_lib.stream import create_chunk
from langchain_openai import ChatOpenAI
from langchain_core.messages import HumanMessage

@morph.func
def langchain_chat_app(context: MorphGlobalContext):
    prompt = context.vars["prompt"]
    # thread_id can be used to identify the chat thread
    thread_id = context.vars["thread_id"]
    model = ChatOpenAI(model="gpt-4o-mini")

    # chat
    messages = [HumanMessage(content=prompt)]
    response = model.invoke(messages)

    for token in model.stream(messages):
        yield create_chunk(token.content)

MDX

export const title = "LangChain Chat App"

# LangChain Chat App

<LLM postData="langchain_chat_app" />

Result