app.py

import gradio as gr
from langchain.llms import HuggingFacePipeline
from langchain.chains import ConversationChain
from transformers import AutoModelForCausalLM, AutoTokenizer, pipeline

# Load pre-trained model and tokenizer from Hugging Face
model_name = "HuggingFaceH4/zephyr-7b-beta"  # You can replace this with other conversational models
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name)

# Create a pipeline for conversational tasks
hf_pipeline = pipeline("text-generation", model=model, tokenizer=tokenizer)

# Wrap the pipeline in a LangChain LLM
llm = HuggingFacePipeline(pipeline=hf_pipeline)

# Create a conversation chain with memory
from langchain.memory import ConversationBufferMemory
memory = ConversationBufferMemory()
conversation = ConversationChain(llm=llm, memory=memory)

# Define a function for Gradio to handle conversation
def chatbot(user_input):
    response = conversation.run(user_input)
    return response

# Gradio UI
with gr.Blocks() as demo:
    gr.Markdown("## 🤖 Chatbot with Hugging Face and LangChain")
    chatbot_interface = gr.Chatbot()
    user_input = gr.Textbox(label="Type your message:", placeholder="Say something...")
    submit_button = gr.Button("Send")
    
    # Bind the input and output
    submit_button.click(chatbot, inputs=user_input, outputs=chatbot_interface)

# Launch the app
demo.launch()