Run your flask app under twisted wsgi, ALWAYS.

new_app.py

if __name__ == "__main__":
    reactor_args = {}
    
    def run_twisted_wsgi():
        from twisted.internet import reactor
        from twisted.web.server import Site
        from twisted.web.wsgi import WSGIResource

        resource = WSGIResource(reactor, reactor.getThreadPool(), app)
        site = Site(resource)
        reactor.listenTCP(5000, site)
        reactor.run(**reactor_args)
        
    if app.debug:
        # Disable twisted signal handlers in development only.
        reactor_args['installSignalHandlers'] = 0
        # Turn on auto reload.
        import werkzeug.serving
        run_twisted_wsgi = werkzeug.serving.run_with_reloader(run_twisted_wsgi)

    run_twisted_wsgi()

old_app.py

if __name__ == "__main__":
    app.run()

Thanks for the code. How to run this app with the debug flag?

Thanks for the code. How to run this app with the debug flag?

Just activate it via env:

FLASK_DEBUG=1

Thanks for the script. Can you explain what's going? Also how do you control a WSGI app running on Twisted Web?

real Big Thanks from the heart