[FIXED] Unable to connect flutter with flask backend on local host

Issue

I am trying to connect flutter to my flask backend. But flutter gives following error

Unhandled Exception: SocketException: OS Error: Connection refused, errno = 111, address = 127.0.0.1, port = 50512

I even tried using my ipv4 address even localhost even host 0.0.0.0 and tried various ports but everytime the port keeps changing in flutter error. Sometimes like this

 Unhandled Exception: SocketException: OS Error: Connection refused, errno = 111, address = 127.0.0.1, port = 39223

Can anyone suggest how do I solve this. Here is my flask code

port = int(os.environ.get('PORT', 5000))
if __name__ == '__main__':
    app.run(debug=True, host='127.0.0.1', port=port) // changing to 0.0.0.0 also doesn't work neither different ports

I am able to connect to heroku server but not on localhost.

Solution

Try giving 'localhost' as host in app.run() and port 5000. It will work on your real device. If using emulator then can use "10.0.2.2". Let me know if it works for you.

Answered By - user13116294