Fetch Fails with "Network request failed" only on Android

[jmedran]

Summary

Hi Expo Team - On Android async Fetch request fails with an ambiguous "Network request failed" error only on Android. iOS works great. This happens both locally in Expo Go, and in a production apk build on a physical device. Oddly enough, this only happens for ONE endpoint. Currently, I call 4 endpoints using fetch, and 3 work on Android. I highly doubt this is an issue with my server, because the fetch call that fails never makes it to the server. Greatly appreciate any help!

Managed or bare workflow? If you have ios/ or android/ directories in your project, the answer is bare!

managed

What platform(s) does this occur on?

Android

SDK Version (managed workflow only)

SDK 44

Environment

expo-env-info 1.0.2 environment info:
System:
OS: macOS 12.2.1
Shell: 5.8 - /bin/zsh
Binaries:
Node: 14.17.0 - /usr/local/bin/node
Yarn: 1.22.15 - ~/.npm-global/bin/yarn
npm: 6.14.13 - /usr/local/bin/npm
Managers:
CocoaPods: 1.11.2 - /usr/local/bin/pod
SDKs:
iOS SDK:
Platforms: DriverKit 21.2, iOS 15.2, macOS 12.1, tvOS 15.2, watchOS 8.3
IDEs:
Xcode: 13.2.1/13C100 - /usr/bin/xcodebuild
npmPackages:
babel-preset-expo: 9.0.1 => 9.0.1
expo: ^44.0.0 => 44.0.4
react: ^17.0.1 => 17.0.2
react-native: ^0.64.3 => 0.64.3
react-navigation: ^4.4.0 => 4.4.4
npmGlobalPackages:
eas-cli: 0.47.0
expo-cli: 5.2.0
Expo Workflow: managed

Reproducible demo

Fetch call that fails:

export const updateEmailAction = (newEmail) => {
  return dispatch => {
    dispatch(triggerUpdateEmail());
    return getAuthToken(newEmail).then(request => {
      fetch(UPDATE_EMAIL_ENDPOINT, request)
      .then(response => {
        if(response.status === 200){
          dispatch(updateEmailSuccess())
        }else throw Error(response.error);
        })
        .catch(e => {
          console.log("ERROR", e.message);
          dispatch(updateEmailError())
        });
    })
  };
}

where getAuthToken() is:

const getAuthToken = (newEmail) => {
  return firebase.auth().currentUser.getIdToken().then((idToken) =>{
    const request = {
      method: 'POST',
      headers:{
        'Authorization': `Bearer ${idToken}`
      },
      body: newEmail
    }
    return request;
  });
}

Note: getAuthToken works fine and is not the cause of the issue. The issue happens with fetch()

Fetch call that works:

export const deleteAccountAction = () => {
  return dispatch => {
    dispatch(triggerDeleteAccount());
    return getAuthToken().then(request => {
      fetch(DELETE_USER_ENDPOINT, request)
        .then(response => {
          dispatch(deleteAccountSuccess(response))
        })
        .catch(e => {
          console.log(e);
          dispatch(deleteAccountError())
        });
    })
  };
}

As you can see, these fetch calls are essentially configured the same. The main difference is the URL to which they point. As I previously mentioned, the server isn't receiving the request for the failed fetch. Its not rejecting the request, the fetch just isn't happening. So strange. Please help - I've been scouring the internet for days without any lead. The error "Network request failed" is far too ambiguous. Thank you!

[edenriquez]

My team and I spend the last 2 days debugging this after update to expo 44 as well and we saw the same behaviour, we had to rollback to a previous version because of this.

[raajnadar]

I had similar issue with axios and android expo managed, What I did was using flipper to inspect the request & response headers, I found that with axios for api the content type was not correct it was not sending the boundary.

axios/axios#4406 (comment)

axios/axios#4406 (comment)

The best way to debug is using the flipper or remote js debug & compare the working api call request & response with the not working one.

[trayldev]

Are there any updates to this posting? I'm hitting the same snags today, tried rolling back to axios@0.24.0 and expo@42.0.0 with no luck so far. Not sure if this root issue has been fixed since February. Thanks!

[ezratechdev]

Am facing a similar issue.Am trying to upload a file using form data.Has there been a fix to this?

[hugoqueiros-parfois]

My app was making the fetch like 2 days ago, and now it gives me this error. It was some expo update? Any updates?

[margins200]

Another option! scan the QR code with expo clients

[rinathakkar]

I am facing same issue in "Network request failed" error only on Android in Expo. Below solution works for me both platform (Android and iOS):

#2402 (comment)
https://stackoverflow.com/a/64397804

[Ulrich-HOUNGBO]

I get the same error for my login form with expo go but when I launch it on the web everything works fine

[abdulmuksith3]

I suffer from the same issue only on some Android devices. However, on some devices when I completely close the app and re-open the error seems to be gone. Any idea what is wrong or solutions?

Managed Workflow
Expo: 44.0.0
RN: 0.64.3

[WillenOLeal]

Having the same issue on expo SDK 46

[louischan]

In my case, the issue was caused by incomplete SSL certificate chain on the web server. Adding the intermediate certificate solved it.

[ewfian]

In my case, the issue was caused by incomplete SSL certificate chain on the web server. Adding the intermediate certificate solved it.

Same case here.

[garrettg123]

Seeing this on Expo v47 (works on iOS). Already using android:usesCleartextTraffic="true".

[dmahajan980]

Can confirm this still exists. I'm facing the same issue on Expo SDK 47 (managed workflow) for Android.

[dmahajan980]

Okay, so I was able to get through this by setting the Content-Type header.

fetch(<SOME_URL>, {
  ...
  headers: {
    ...
    'Content-Type': 'application/json'
  }
})

[danyhiol]

I also have this same issue on both the emulator and the device on android(only).
After some searching and debugging, I could extract the error from adb: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found. And after googling for hours, couldn't find any way of solving this. I ended up thinking this was an issue with the server: https://<domain>:<port>/. But requests to the same server are working on IOS and on WEB or tools such as Postman. Some solutions suggest adding mimeType to the formData option. But I am not posting a file, but some parameters. In fact, my server accepts only formData. Moreover, not all requests are failing.

[garrettg123]

I saw this error while using localhost in development (which works on iOS). Changing this to my machine's static ip (eg. 192.168.0.100) fixes this on Android, although it's a bit annoying when it changes.

[danyhiol]

@garrettg123 can you elaborate? Where do I make this change? My server is not local, but remote: https://<domain>:<port>/. If you mean this, I doubt it would help because of the remote host.

[expo-bot]

Hi there! It looks like your issue requires a minimal reproducible example, but it is invalid or absent. Please prepare such an example and share it in a new issue.

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[vincentdesmares]

I saw this error while using localhost in development (which works on iOS). Changing this to my machine's static ip (eg. 192.168.0.100) fixes this on Android, although it's a bit annoying when it changes.

I can confirm that switching my Graphql calls from http://localhost:8080 to http://191.168.1.16:8080 solved the issue.

I had only the problem on Android (emulator and phone) but not on IOS and web.

[saibbyweb]

In my case, the issue was caused by incomplete SSL certificate chain on the web server. Adding the intermediate certificate solved it.

For hosted backends, it definitely has something to do with SSL. As a temporary fix, changing the url prefix to http from https worked for me.

[ZuulAndRibbon]

In my case, the issue was caused by incomplete SSL certificate chain on the web server. Adding the intermediate certificate solved it.

the same case.Because u don't do this action that .crt and .ca-bundle files have not been combined in one .crt file before uploading to server.You need to do this action before configure ssl in nginx.conf

[linonetwo]

Another case: If your site is using *.crt/*.key SSL pairs, try use *.pem/*.key instead. *.pem file include the necessary root cert for Android devices that does not know your SSL issuer.

[sovetski]

I had the same error and my problem was coming from .env file, my keys were not prefixed.

I changed API_URL to EXPO_PUBLIC_API_URL and it worked.

Docs: https://docs.expo.dev/guides/environment-variables/

[adamwoolhether]

I saw this error while using localhost in development (which works on iOS). Changing this to my machine's static ip (eg. 192.168.0.100) fixes this on Android, although it's a bit annoying when it changes.

This did it for me too, i have to set my backend to listen on the same IP as my macbook, rather than "localhost". Only then can I connect the App with my Android device or simulator.

This isn't an issue with iOS or iOS simulator.