React Native backend with push notifications

If you mean “how do I set up a backend for a React Native app to send push notifications?”, here’s the usual architecture:

High-level setup

React Native app:

• Requests push permission
• Gets a push token from FCM (Android) and/or APNs (iOS)
• Sends that token to your backend

Backend:

• Stores device tokens for each user
• Triggers notifications when needed
• Sends pushes through Firebase Cloud Messaging (FCM) or a provider like OneSignal, Expo Push, etc.

Recommended approach

For most apps:

• React Native app: use @react-native-firebase/messaging or Expo notifications
• Backend: use Firebase Admin SDK to send notifications via FCM
• Database: store user IDs + device tokens

Basic flow

1. User logs in on app
2. App fetches push token
3. App sends token to backend API
4. Backend saves token
5. Backend sends notification to token(s) when event happens

Example backend stack

• Node.js + Express/NestJS
• PostgreSQL or MongoDB for token storage
• Firebase Admin SDK for sending push notifications

Example Node.js backend sending a push via FCM

import admin from "firebase-admin";
import serviceAccount from "./serviceAccountKey.json" assert { type: "json" };

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
});

async function sendPush(token, title, body) {
  const message = {
    token,
    notification: {
      title,
      body,
    },
  };

  return admin.messaging().send(message);
}

Example API to save token

app.post("/push-token", async (req, res) => {
  const { userId, token } = req.body;
  await db.pushTokens.upsert({ userId, token });
  res.json({ success: true });
});

Things to watch out for

• Token refresh: device tokens can change, so update them when they do
• Multiple devices per user: store multiple tokens
• Invalid tokens: remove old/expired tokens
• Platform differences: iOS needs APNs setup, Android needs FCM config
• Background notifications: handled differently on iOS/Android

If you’re using Expo

You can use:

• expo-notifications
• Expo push service for sending notifications from backend

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If you want, I can give you:

1. a complete Node.js backend example,
2. a React Native client setup, or
3. an Expo-based solution.