Silent push

A silent push wakes your app in the background and hands it the data set on the message, without showing anything to the person. Use this page to set your app up to receive silent pushes.

How it works

When you send a silent push, the device wakes your app in the background. The SDK reports Delivered to Customer.io and hands your JavaScript handler the key/value data set on the message. A silent push never shows anything, so the SDK never reports Opened.

Silent push needs customerio-expo-plugin 4.5.0 or later and customerio-reactnative 7.3.0 or later. On iOS, it also needs Expo SDK 53 or later.

Set up silent push

1. Add the Remote notifications background mode to your app config. Without it, iOS doesn’t wake your app for a silent push.

   JSON

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   {
     "expo": {
       "ios": {
         "infoPlist": {
           "UIBackgroundModes": ["remote-notification"]
         }
       }
     }
   }

2. Set the handler in your entry file. On Android, a silent push that starts your app in the background runs your entry file without mounting your app, so a handler you set inside a component would miss it. If you use Expo Router, add an index.js file and point main in your package.json at it:

   JAVASCRIPT

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   // index.js
   import 'expo-router/entry';
   import { CustomerIO } from 'customerio-reactnative';
   
   CustomerIO.pushMessaging.setBackgroundPushHandler(async ({ deliveryId, data }) => {
     // data holds the keys and values set on the message.
     // Key your work on deliveryId: the same push can arrive more than once.
     await refreshInbox(data);
   });

On iOS, the plugin passes silent pushes from your generated AppDelegate to the Customer.io SDK. The SDK reports Delivered for each silent push and hands it to your handler once your JavaScript sets one. Every other push goes to Expo and your other libraries as before. Android doesn’t need anything from the plugin.

The handler works the same way as in the React Native SDK. See React Native silent push for how the handler runs on each platform, and how to stop it.

Use React Native Firebase

If your app uses React Native Firebase, handle silent pushes in one place. React Native Firebase’s handlers see silent pushes either way.

• To handle them with setBackgroundPushHandler, set android.setHighPriorityPushHandler to true in your plugin config, so Customer.io’s Firebase service gets each FCM message.
• To handle them in React Native Firebase, leave android.setHighPriorityPushHandler unset and don’t call setBackgroundPushHandler. See React Native silent push for the code.

What to plan for

Silent pushes reach an Expo app under the same limits as a React Native app. See what to plan for in React Native silent push.