app.py

import gradio as gr

from langchain import PromptTemplate, LLMChain
from langchain.llms import HuggingFaceHub

template = """Question: {question}

Answer: Let's think step by step."""


def run(
    question: gr.Textbox = None,
    repo_id: gr.Dropdown = None,
    temperature: gr.Slider = 0.5,
    max_length: gr.Slider = 64,
):
    prompt = PromptTemplate(template=template, input_variables=["question"])
    llm = HuggingFaceHub(
        repo_id=repo_id,
        model_kwargs={"temperature": temperature, "max_length": max_length}
    )
    llm_chain = LLMChain(prompt=prompt, llm=llm)
    result = llm_chain.run(question)
    print(result)
    return result


inputs = [
    gr.Textbox(label="Question"),
    gr.Dropdown(["google/flan-t5-xxl", "google/flan-t5-base"],
                value="google/flan-t5-xxl", label="Model", allow_custom_value=True),
    gr.Slider(0.0, 1.0, value=0.5, step=0.05, label="Temperature"),
    gr.Slider(10, 1000, value=64, label="Max Length"),
]

title = "Langchain w/ HF Models"

gr.Interface(
    fn=run,
    inputs=inputs,
    outputs='label',
    title=title,
).launch()