app.py

import gradio as gr
from huggingface_hub import InferenceClient

client = InferenceClient("HuggingFaceH4/zephyr-7b-beta")


def _history_to_messages(history):
    messages = []
    if not history:
        return messages
    # Gradio 5 uses list[dict]; older ChatInterface used list[tuple]
    if isinstance(history[0], dict):
        for item in history:
            role = item.get("role")
            content = item.get("content")
            if role in {"user", "assistant"} and content:
                messages.append({"role": role, "content": content})
        return messages
    for user_msg, assistant_msg in history:
        if user_msg:
            messages.append({"role": "user", "content": user_msg})
        if assistant_msg:
            messages.append({"role": "assistant", "content": assistant_msg})
    return messages


def respond(message, history, system_message, max_tokens, temperature, top_p):
    messages = [{"role": "system", "content": system_message}]
    messages.extend(_history_to_messages(history))
    messages.append({"role": "user", "content": message})

    response = ""
    try:
        for chunk in client.chat_completion(
            messages,
            max_tokens=int(max_tokens),
            stream=True,
            temperature=temperature,
            top_p=top_p,
        ):
            token = chunk.choices[0].delta.content
            if token:
                response += token
                yield response
    except Exception as exc:
        yield f"Model call failed: {exc}. Add HF_TOKEN in Space secrets if needed."


demo = gr.ChatInterface(
    respond,
    additional_inputs=[
        gr.Textbox(
            value="You are a friendly chatbot. Speak as if you are age n and a given sex. Example: n = 17 and sex = male",
            label="System message",
        ),
        gr.Slider(minimum=1, maximum=2048, value=512, step=1, label="Max new tokens"),
        gr.Slider(minimum=0.1, maximum=2.0, value=0.7, step=0.1, label="Temperature"),
        gr.Slider(minimum=0.1, maximum=1.0, value=0.95, step=0.05, label="Top-p"),
    ],
)

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