main.pyasync def app(scope, receive, send): assert scope['type'] == 'http' await send({ 'type': 'http.response.start', 'status': 200, 'headers': [ (b'content-type', b'text/plain'), (b'content-length', b'13'), ], }) await send({ 'type': 'http.response.body', 'body': b'Hello, world!', }) Usage: uvicorn [OPTIONS] APP Options: --host TEXT Bind socket to this host. [default: 127.0.0.1] --port INTEGER B