test_server.py

import uvicorn
from fastapi import FastAPI

class Temp:
    def __init__(self):
        self.app = FastAPI()
        self.app.add_api_route("/", self.index, methods=["GET"])
    
    async def index(self):
        return {"message": "Hello, World!"}

    def run(self):
        uvicorn.run(self.app, port=7860, workers=1)


Temp().run()