Hey there! We've found the following might help you get unblocked faster: - [📚 Application Failed to Respond](https://docs.railway.com/reference/errors/application-failed-to-respond) - [🧵 Deploy app with vue 3 and vite](https://station.railway.com/questions/deploy-app-with-vue-3-and-vite-ed465a4f) - [🧵 Flask App: Application Failed to Respond](https://station.railway.com/questions/flask-app-application-failed-to-respond-f857211b) - [🧵 Persistent 502 "Application failed to respond" on new PHP/Nginx Project](https://station.railway.com/questions/persistent-502-application-failed-to-re-86affad9) If you find the answer from one of these, please let us know by solving the thread!

Hey manrabs! This "Application failed to respond" error with Flask is pretty common and usually comes down to port config or how the app is being served.Few things to check:Port - most important! In ur app.run(), u need:pythonapp.run(host='0.0.0.0', port=int(os.environ.get('PORT', 5000)))Railway automatically injects the PORT variable, so u gotta use it.In the Dockerfile - if ur using one, make sure ur exposing the right port:dockerfileEXPOSE $PORTCheck if Flask is actually starting - in the logs, u should see something like "Running on http://0.0.0.0:XXXX". If that line isn't there, the problem is in startup.Environment variables - make sure there's no missing config that ur app needs to run.Can u paste ur main app.py and the Dockerfile here? That way I can take a more specific look at what might be going on.Quick tip: test locally with docker build . && docker run -p 5000:5000 -e PORT=5000 <image> to see if it runs properly before deploying.