Running ui.run from an asynchronous function with reload=False causes an error

[MaidScientistIzutsumiMarin]

First Check

• I added a very descriptive title here.
• This is not a Q&A. I am sure something is wrong with NiceGUI or its documentation.
• I used the GitHub search to find a similar issue and came up empty.

Example Code

import asyncio
from dataclasses import dataclass

from httpx import AsyncClient
from nicegui import ui


@dataclass
class Root:
    client: AsyncClient

    async def setup(self) -> None:
        ui.label("Hello, world!")


async def main() -> None:
    async with AsyncClient() as client:
        ui.run(Root(client).setup, reload=False)


asyncio.run(main())

Description

Start the app. It crashes immediately with:
RuntimeError: asyncio.run() cannot be called from a running event loop

This crash only happens when reload=False is present in the above example.

NiceGUI Version

3.2.0

Python Version

3.14.0

Browser

Other

Operating System

Windows

Additional Context

Having reload=False in required in situations like if the program is being packaged for distribution or called from an entry point. Is there an alternative pattern that should be used to handle asynchronous resources liked this?

[rodja]

Might be possible with some modifications/additons to ui.run. We must somehow configure a server start without creating a new event loop. How would that look with FastAPI?

[spacemanspiff2007]

It would look like this.
The FastAPI App can also be used directly as the first parameter:

    app = FastAPI()
    config = uvicorn.Config(app, host="127.0.0.1", port=8000, loop="asyncio")
    server = uvicorn.Server(config)
    await server.serve()

How about providing an async_run()?