expo: [expo-notifications] Background notification tasks not working

Expo’s push API does not accept the content-available key. You’ll need to send directly through APNs. Please refer to the Push API documentation: https://docs.expo.dev/push-notifications/sending-notifications/

Hi Guys, I found out a solution in order to use content-available: 1 flag in expo server sdk. Just use "_contentAvailable": true in your payload Example payload for ios { to: <push_token>, "_contentAvailable": true}

Example payload for android { to: <push_token>, priority: "high"}

Just use the above payload. For me it worked like a charm

Hi! I confirm that the background task works on Android but not on iOS. I’m on SDK 45 and using a development build.

This is my notification payload in PHP

$message = new ExpoMessage(array(
	'title' => 'Test J! 4',
	'body'  => 'Test body',
	'sound' => 'default',
	'data'  => array(
		'someData' => 'goes here'
	),
	'content-available' => 1,
));

My setupNotificationsBackgroundTask.js hook

import { useEffect } from 'react';
import * as TaskManager from 'expo-task-manager';
import { Platform } from 'react-native';
import * as Notifications from 'expo-notifications';
import usePersistAppContextStore from '../stores/usePersistAppContextStore';

const BACKGROUND_NOTIFICATION_TASK = 'BACKGROUND-NOTIFICATION-TASK';
TaskManager.defineTask(BACKGROUND_NOTIFICATION_TASK, ({ data, error, executionInfo }) => {
  console.log('Received a notification in the background!', Platform.OS, data); // Not called on iOS
});

export default function setupNotificationsBackgroundTask() {
  useEffect(() => {
    registerBackgroundTask()
      .then(() => null)
      .catch(() => null);
  }, []);
}

async function registerBackgroundTask() {
  try {
    await Notifications.registerTaskAsync(BACKGROUND_NOTIFICATION_TASK);
  } catch (e) {
    console.log(e);
  }
}

app.config.js

    ios: {
...
...
      infoPlist: {
...
...
        UIBackgroundModes: ['remote-notification'],
      },
    },
...
...

If the ‘content-available’ => 1 parameter is not supported by the Expo API message payload, then, please state that clearly in the docs, because currently it states:

Please note: In order to handle notifications while the app is backgrounded on iOS, you must add remote-notification to the ios.infoPlist.UIBackgroundModes key in your app.json, and add “content-available”: 1 to your push notification payload. Under normal circumstances, the “content-available” flag should launch your app if it isn’t running and wasn’t killed by the user, however, this is ultimately decided by the OS so it might not always happen.

And maybe it should add: and add “content-available”: 1 to your push notification payload, currently only supported by native APNs payloads, not supported in Expo notifications API message payloads

Please advise.

@cruzach So if I am seeing the following error when running my app via Expo Go (managed), is this expected? I have the proper plist key & value UIBackgroundModes: ['remote-notification'], and have tried both killing & reinstalling the expo go app but still see the same Error message.

Error: Background remote notifications have not been configured. To enable it, add remote-notification to UIBackgroundModes in the application’s Info.plist file.]

If backgrounded remote notification handling & async task definitions only work when running the app itself outside of Expo Go, how do you recommend debugging the async task code?

–

And furthermore, when the documentation mentions including “content-available”: 1 in the push notification payload, does that mean to include it in the data key as below?

const messages: ExpoPushMessage[] = [
          {
            title: senderFullName,
            body: message,
            to: tokens,
            data: {
              'content-available': 1,
            },
          },
        ];
        ```

Expo’s push API does not accept the content-available key. You’ll need to send directly through APNs. Please refer to the Push API documentation: https://docs.expo.dev/push-notifications/sending-notifications/

@cruzach are you please able to confirm that this is still the case, and if possible could you please explain why Expo’s push API does not accept the content-available key? (and will it ever accept this key?)

We are trying to update the iOS badge count with the background task following the docs, and the docs simply say Please note: In order to handle notifications while the app is backgrounded on iOS, you must add remote-notification to the ios.infoPlist.UIBackgroundModes key in your app.json, and add “content-available”: 1 to your push notification payload. Under normal circumstances, the “content-available” flag should launch your app if it isn’t running and wasn’t killed by the user, however, this is ultimately decided by the OS so it might not always happen.

The docs don’t confirm that you would then have to go through APNs directly, and this is the only place I can find where content-available is mentioned.

If I could please have some confirmation that we would need to switch to use the native device token instead of the expo push token, and send directly to APNs, then I can communicate with the backend team and project manager that we MUST do this and allocate our resources accordingly.

Thank you 🙏

Hi Guys, I found out a solution in order to use content-available: 1 flag in expo server sdk. Just use "_contentAvailable": true in your payload Example payload for ios { to: <push_token>, "_contentAvailable": true}

Example payload for android { to: <push_token>, priority: "high"}

Just use the above payload. For me it worked like a charm

Unbelievably this is working for us. Using BACKGROUND-NOTIFICATION-TASK to update our badge count. @ahmed-sharief5 how did you find this solution?

Maybe we should upvote this https://expo.canny.io/feature-requests/p/background-notification-support-for-expo-notifation-service-api

Expo’s push API does not accept the content-available key. You’ll need to send directly through APNs. Please refer to the Push API documentation: https://docs.expo.dev/push-notifications/sending-notifications/

Is this a feature that could be supported in the future? As I understand this, it’s impossible to send notifications for an app while the app is backgrounded or closed in iOS if you use Expo’s push API?

I created a feature request.

https://expo.canny.io/feature-requests/p/background-notification-support-for-expo-notifation-service-api

@chris-chao any luck in past 20 days? I’m on SDK 42 My code is similar to what is on the official documentation.

const BACKGROUND_NOTIFICATION_TASK = "BACKGROUND-NOTIFICATION-TASK";
let bg_notif = null;
TaskManager.defineTask(
    BACKGROUND_NOTIFICATION_TASK,
    ({ data, error, executionInfo }) => {
        console.log("WHOOOOOOOOOO");
        console.log("Received a notification in the background!", data);
        bg_notif = data.notif;
        // Do something with the notification data
    }
);

Notifications.registerTaskAsync(BACKGROUND_NOTIFICATION_TASK);

Not working whether app is running in background or killed. I’m on Android device btw.

The docs explicitly state “Handling incoming notifications when the app is not in the foreground (not supported in Expo Go)”. You can test that behavior by either running expo run:ios, building your standalone app, or by using the expo-dev-client library

when the documentation mentions including “content-available”: 1 in the push notification payload, does that mean to include it in the data key as below?

If you’re using APNs directly, please refer to the APNs docs for where to place keys

Agreed about adding it. It feels like a pretty low lift, no? Maybe I’m missing something about the complexity given how common of a use case it is

I spoke with someone at Expo and when I asked about the content-available flag, this was the response:

Hi - the content available flag isn’t part of the Expo push notification service’s public interface. If you use another APNs provider you can set it though

It also sounded like it wasn’t on the 2022 roadmap either.

We’ve since migrated to AWS’ SNS for iOS pushes

Hello @jcalem @brentvatne
I am having an issue with updating the state ( context API) from inside the TaskManager ( as it’s defined in the global scope), first of all, is it possible to do so ? if the answer is Yes, could you please give me an example on how to implement this. Thank you.

I read this wrong. You can still receive notifications if the App is backgrounded or closed. You just can’t directly act on them using code in the app in those situations. I am guessing here, but if you touch the notification, I would imagine you can still act on it after the app opens, correct?

Hello,

I did totally the same, but on iOS, I have this warning : " Error: Background remote notifications have not been configured. To enable it, add remote-notification to UIBackgroundModes in the application’s Info.plist file.]".

In any case, in the documentation they say: “Handling incoming notifications when the app is not in the foreground (not supported in Expo Go)” but here: https://blog.expo.dev/expo-sdk-42-579aee2348b6 they say “SDK 42 brings support for two highly-requested expo-notifications features: handling push notifications while your app is in the background, and using custom notification sounds in your managed workflow app”, where is the truth?

Thanks.

{
  _contentAvailable: true,
}

This is work, but background will run just one time only till your re-open the app.

@jamespb97

@dwbelliston I found out this in official documentation of firebase. Does it works for you after disabling “Do not disturb”?

Hi @Stevemoretz ! sorry to bother, woul yo be so kind to share if there’s need to use an Expo dev build to integrate FCM for Android and iOS? Also,what’s the cost of FCM service?

Thanks!

Hi how you doing? If by expo dev build, you mean a custom build then yes, I used eas and built it really easy, I used the rn-firebase library and it has eas support out of the box so really easy to setup.

Regarding your second question FCM is completely free, as a matter of fact expo notification (for Android only) is using the FCM.

I spoke with someone at Expo and when I asked about the content-available flag, this was the response:

Hi - the content available flag isn’t part of the Expo push notification service’s public interface. If you use another APNs provider you can set it though

It also sounded like it wasn’t on the 2022 roadmap either.

We’ve since migrated to AWS’ SNS for iOS pushes

That’s bad news, we also migrated to FCM and surprisingly this feature was supported out of the box and without any problems, took me a day to set it up and make it running.

Do most Expo developers reply on sending notifications directly through APNs for iOS instead of using Expo’s push notification system?

I suppose I’m just surprised this isn’t a bigger issue that it’s currently not possible using Expo’s Push API to increment the app badge count when receiving notifications.

Maybe I’m still misunderstanding? @Stevemoretz

As we state in the docs:

Under normal circumstances, the “content-available” flag should launch your app if it isn’t running and wasn’t killed by the user, however, this is ultimately decided by the OS so it might not always happen.

I’ve seen this myself, and what helped was to fully kill all backgrounded apps, relaunch my app, and then try sending the notification again. You should also make sure “Background App Refresh” is allowed for your application in Settings