app.py

import os

import gradio as gr
import openai
import tiktoken

# Config
CHAT_MODELS = [
    "gpt-4",
    "gpt-4-32k",
    "gpt-3.5-turbo",
]
DEFAULT_MODEL = "gpt-3.5-turbo"
TOKEN_PRICE = {
    "gpt-3.5-turbo": 0.002 / 1000,
    "gpt-4": 0.06 / 1000,
    "gpt-4-32k": 0.12 / 1000,
}

# Private
_tokens: int = 0
_selected_model = DEFAULT_MODEL
_encoding = tiktoken.encoding_for_model(DEFAULT_MODEL)
_api_key = os.environ.get("OPENAI_API_KEY", "")
_show_openai_settings = _api_key == ""


def count_tokens(prompt_text: str) -> int:
    """Return the number of tokens in the prompt text"""
    return len(_encoding.encode(str(prompt_text)))


def get_cost(tokens: int, model: str) -> float:
    return TOKEN_PRICE.get(model, 0) * tokens


def prompt(prompt_text: str, api_key: str, model: str) -> str:
    global _tokens
    global _selected_model
    global _encoding

    # Check if selected model has changed
    if model != _selected_model:
        _selected_model = model
        _encoding = tiktoken.encoding_for_model(_selected_model)

    _tokens += count_tokens(prompt_text)

    openai.api_key = api_key
    content = openai.ChatCompletion.create(
        model=_selected_model,
        messages=[
            {"role": "system", "content": "You are a helpful assistant."},
            {"role": "user", "content": prompt_text},
        ],
        temperature=0,
    )["choices"][0]["message"]["content"]

    _tokens += count_tokens(content)
    cost = get_cost(_tokens, model)

    return (
        content,
        _tokens,
        cost,
    )


with gr.Blocks() as demo:
    gr.Markdown("## Test your prompts and see how much it costs!")
    with gr.Row():
        with gr.Column(scale=1):
            txt_api_key = gr.Textbox(
                label="OpenAI API Key",
                value=_api_key,
                visible=_show_openai_settings,
                type="password",
                placeholder="sk-...",
            )
            dd_model = gr.Dropdown(
                choices=CHAT_MODELS,
                value=DEFAULT_MODEL,
                label="Model",
            )
            num_tokens = gr.Number(value=0, label="Tokens used")
            num_cost = gr.Number(value=0, label="Estimated cost in $", precision=3)
        with gr.Column(scale=3):
            txt_prompt = gr.Textbox(label="Prompt")
            txt_response = gr.TextArea(label="Model response")
            with gr.Row():
                gr.Button("Prompt").click(
                    fn=prompt,
                    inputs=[txt_prompt, txt_api_key, dd_model],
                    outputs=[txt_response, num_tokens, num_cost],
                )
                gr.Button("Clear").click(
                    fn=lambda _: ("", ""),
                    inputs=txt_prompt,
                    outputs=[txt_prompt, txt_response],
                )


demo.launch()