How do I set up push notifications for iOS and Android with one API?

The usual way to do this is to use a push notification service/abstraction layer so your app talks to one API, while the service handles the platform-specific details for APNs (iOS) and FCM (Android).

Common options

• Firebase Cloud Messaging (FCM)
  • Good for Android, and can also deliver to iOS through APNs.
  • Often the simplest “single API” if you already use Firebase.
• OneSignal
  • Very easy to integrate.
  • One API for iOS + Android.
  • Includes dashboards, segmentation, scheduling, etc.
• AWS SNS / Pinpoint
  • Good if you’re already on AWS.
• Pusher Beams / Airship / Mixpanel Engage / Braze
  • More advanced marketing/product messaging platforms.

Recommended architecture

1. Mobile app

   • Registers for notifications.
   • Gets a device token:
     • iOS: APNs token
     • Android: FCM token
   • Sends token to your backend with user/session info.

2. Your backend

   • Stores each user’s push tokens.
   • Uses one provider API (e.g., OneSignal or FCM) to send notifications.
   • Optionally groups tokens by user, segment, locale, etc.

3. Provider

   • Routes to APNs for iOS and FCM for Android behind the scenes.

Setup steps

1) Configure platform credentials

• iOS
  • Enable Push Notifications capability in Xcode.
  • Create an APNs auth key in Apple Developer.
  • Upload APNs credentials to your chosen push provider.
• Android
  • Create/configure Firebase project.
  • Add google-services.json to your Android app.
  • Enable FCM.

2) Add SDKs

• Add the provider’s SDK to both apps.
• Initialize it on app startup.

3) Request notification permission

• iOS requires user permission prompt.
• Android 13+ also requires runtime permission for notifications.

4) Register and sync tokens

• On token refresh, send the new token to your backend/provider.

5) Send notifications from one API

Example payload conceptually:

{
  "target_user_id": "123",
  "title": "New message",
  "body": "You have a new message",
  "data": {
    "screen": "inbox",
    "thread_id": "abc"
  }
}

If you want the simplest single-API solution

Use OneSignal:

• One API for both iOS and Android
• Minimal backend work
• Easy token/device management

If you want to build it yourself

Use FCM as your unified layer:

• Android uses FCM directly
• iOS can also be addressed via FCM, but you still need APNs set up underneath
• Your backend sends to FCM only

Important gotchas

• Handle token rotation
• Remove invalid/expired tokens
• Use collapse keys / notification grouping to avoid spam
• Separate notification payload (displayed automatically) vs data payload (handled by app)
• Respect iOS background delivery limitations

If you want, I can give you:

1. a step-by-step setup for OneSignal,
2. a DIY setup with FCM + APNs, or
3. example code for backend + iOS + Android.