app.py

#https://python.langchain.com/docs/how_to/binding/
import gradio as gr
from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate

def process_with_binding(text, stop_word, api_key):
    try:
        # Initialize the model
        model = ChatOpenAI(
            openai_api_key=api_key,
            model="gpt-4o-mini"
        )
        
        # Create prompt template
        prompt = ChatPromptTemplate.from_template(
            "Write a story about {text}. Make it detailed."
        )
        
        # Create chain with binding
        chain = prompt | model.bind(stop=stop_word)
        
        # Get response
        response = chain.invoke({"text": text})
        
        return response.content
        
    except Exception as e:
        return f"Error: {str(e)}"

# Create Gradio interface
demo = gr.Interface(
    fn=process_with_binding,
    inputs=[
        gr.Textbox(label="Topic for story", placeholder="Enter a topic..."),
        gr.Textbox(label="Stop Word", placeholder="Enter a word to stop generation"),
        gr.Textbox(label="OpenAI API Key", type="password")
    ],
    outputs=gr.Textbox(label="Generated Story"),
    title="LangChain Binding Demo",
    description="Generate a story that stops at a specific word"
)

if __name__ == "__main__":
    demo.launch()