Lets create a simple application

from aiohttp import web
from openapi.rest import rest

def create_app():
    return rest(setup_app=setup_app)

def setup_app(app: web.Application) -> None:

if the openapi entry is not specified the server won’t add any of the tooling related to openapi auto-documenation, which means no spec path as specified by the SPEC_ROUTE env variable.