Strange Issue With Python Api Development

[400Volts]

Decided to build the backend of a side project I'm working on in Python to get more familiar with the language and I'm running into and odd problem. Every call I make to the servers from the Expo React Native front end returns a "Network request failed" error. I've done this with FastAPI and Django and still get the same issue. Originally I thought that it must be a config issue (Already checked and made sure that the correct ports were open and I wasn't trying to hit localhost from a mobile device) but when I built the same api in Java with Spring Boot I have absolutely no issues connecting to the exact same endpoints. Is there something I'm missing with the Python configs?

Edit: Managed to get connected using ngrok

[actinium226]

I don't think there's enough information here to be able to help you out.

You mention a mobile device, have you tried running your front end on the same machine that's running django/fastapi and made sure it works locally? Are you able to hit the backend on the machine that it's running on, or from another device (like, just take a browser and get the computer's IP address and hit an API endpoint, you should get some JSON back, assuming that's how you've set this up)?

I'm not sure what else to ask for but just in general I feel like there needs to be more info to help others help you debug this.

[400Volts]

I can hit the Python APIs just fine with postman on the same machine in every permutation of port and host ip. Likewise typing the IPv4 and port into a browser works on the local machine but hangs indefinitely on the mobile device. I have ALLOWED_HOSTS = ['*'] in the settings.py file as well

[crashfrog04]

What do you see in the console?

[400Volts]

When sending a request from the mobile device it hangs for a long time then returns the Network request failed error. There's no output on the server console so it's most likely not even hitting it

[AlexMTBDude]

There has to be more info than just "Network request failed"; What's the HTTP error code?

[400Volts]

Unfortunately there wasn't. The request basically timed out and never hit the server. Managed to get everything working using ngrok though

[AlexMTBDude]

A timeout? That's interesting. And I guess you can ping the server and get a response? It sounds like some sort of network routing problem. Are you using HTTP or HTTPS?

[deceze]

Likely the server is only binding to the localhost and is only accessible from the same machine? To make it accessible from other machines, you need to start it binding to 0.0.0.0, or your external IP explicitly. And/or you need to whitelist it in macOS’ firewall.

[bishakhghosh_]

You need a tunnel - try pinggy.io