How do I trigger push notifications from app events?

To trigger push notifications from app events, you generally need this flow:

1. An app event happens

   • Example: user sends a message, order ships, task is assigned, payment fails.

2. Your backend detects or receives that event

   • Usually via:
     • an API call from the app
     • a database change
     • a queue/job
     • a webhook from another service

3. Your backend decides whether to send a push

   • Check rules like:
     • user opted in
     • notification type is enabled
     • event qualifies
     • not rate-limited / not duplicate

4. Your backend sends the push to a push provider

   • Common providers:
     • FCM for Android / web
     • APNs for iOS
     • or a service like Firebase, OneSignal, AWS SNS, etc.

5. The device receives the push

   • The OS displays it or your app handles it in the foreground/background.

Typical implementation pattern

1) Register the device for push

• App asks permission.
• App gets a push token:
  • iOS: APNs token
  • Android/Web: FCM token
• App sends that token to your backend and associates it with the user.

2) Store user-device mapping

Example:

{
  "userId": "123",
  "deviceTokens": ["token1", "token2"],
  "platform": "ios"
}

3) Emit an event when something happens

Example:

{
  "type": "message.created",
  "userId": "123",
  "messageId": "abc"
}

4) Handle the event and send notification

Your server code might do:

• listen for message.created
• fetch the target user’s tokens
• build notification payload
• send to FCM/APNs

Example architecture

• App
  • triggers an event by calling backend
• Backend
  • processes event
  • creates notification job
• Worker/queue
  • sends push asynchronously
• Push service
  • delivers notification

This is preferred over sending push directly from the app, because push credentials must stay on the server.

Example pseudo-flow

User completes purchase
→ backend saves order
→ backend emits "order.shipped"
→ notification worker listens
→ worker sends push via FCM/APNs
→ user gets notification

Important notes

• Don’t send push notifications directly from client code with provider credentials.
• Use server-side auth for FCM/APNs.
• Handle:
  • invalid/expired tokens
  • retry logic
  • user preferences
  • quiet hours / throttling

If you tell me your stack

I can give you a concrete example for:

• Firebase Cloud Messaging
• iOS (APNs)
• Android
• React Native / Flutter
• Node.js / Python / Java / .NET backend
• OneSignal or Firebase setup