react native and flask api network request failed

Question

I've built a simple api using Flask and a react native front end. I am running both of these on separate ports on my computer. The flask api works properly and can be accessed inside a browser. When I run:

fetch('http://127.0.0.1:5000')
.then((responseJson) => {
  callback(responseJson);
})

I get an error on my android device of "Network request failed". Has anyone experiences this problem before? I have seen other have experienced similar problems but I could not find a solution online. Thanks

score 0 · Accepted Answer · answered Sep 20 '17 at 15:01

0

Use your IP instead of 127.0.0.1. It should work.

More details here: How can I access my localhost through Android phone?

answered Sep 20 '17 at 15:01

Florin Dobre

9,872
3
59
93

score 0 · Answer 2 · answered Sep 20 '17 at 17:27

0

I think you need to execute adb reverse first to connect to your development server. Run the following command.

adb reverse tcp:5000 tcp:5000

Ref: https://facebook.github.io/react-native/docs/running-on-device.html

answered Sep 20 '17 at 17:27

Wanda Ichsanul Isra

2,142
10
19

score 0 · Answer 3 · answered Jun 23 '20 at 07:02

I had this problem for a while, and even putting my IP address didn't work. I figured out that in addition to using your IP address, you need to configure Flask to run on your machine's IP address. You can do it like this:

app.run(host='0.0.0.0')

This worked for me.

react native and flask api network request failed

3 Answers3