capacitor-push-notifications
Sets up and debugs remote push in Capacitor apps with @capacitor/push-notifications (FCM on Android, APNs on iOS), or Capgo alternatives @capgo/capacitor-firebase-messaging and @capgo/capacitor-notifications. Covers APNs keys, Push Notifications capability, AppDelegate `didRegisterForRemoteNotificationsWithDeviceToken` forwarding (stays in AppDelegate under the Capacitor 8.5 UIScene lifecycle), Android 13+ POST_NOTIFICATIONS permission, notification channels and icons, `firebaseMessagingVersion`, foreground `presentationOptions` (Capacitor 9 removes iOS `alert`; use `banner`/`list`), and tap routing. Use when `registration` never fires, iOS returns an APNs token instead of an FCM token, errors like "no valid aps-environment entitlement string found" appear, or notifications do not show. Do not use for local-only notifications or deep link URL handling (capacitor-deep-linking), UIScene migration (capacitor-uiscene-migration), or log capture (ios-android-logs).
How do I install this agent skill?
npx skills add https://github.com/cap-go/capgo-skills --skill capacitor-push-notificationsIs this agent skill safe to install?
- Gen Agent Trust Hubpass
This skill provides a technical guide for implementing push notifications in Capacitor applications using standard industry practices. The only security consideration is the inherent risk of processing untrusted data from external push notification payloads, which is a common but noteworthy attack surface for indirect prompt injection.
- Socketpass
No alerts
- Snykpass
Risk: LOW · No issues
- Runlayerwarn
2/2 files flagged
- ZeroLeakspass
1 finding · Score: 82/100
What does this agent skill do?
Push Notifications in Capacitor
When to Use
TRIGGER when:
- Adding remote push (FCM / APNs) to a Capacitor app
registration/registrationErrornever fire, or the token works on one platform only- iOS token is a 64-hex APNs token but the backend expects an FCM token
- Notifications arrive in background but not in foreground (or vice versa)
- Android 13+ shows no prompt and nothing is delivered
- Upgrading to Capacitor 8.5 (UIScene) or 9 (
alertpresentation option removed)
Do not use:
- Opening the app from
https:///myapp://links:capacitor-deep-linking - Moving AppDelegate code to SceneDelegate:
capacitor-uiscene-migration - Device log capture:
ios-android-logs - Choosing other native plugins:
capacitor-plugins
Choose the plugin first (ask the user if unclear)
| Need | Plugin |
|---|---|
| Official plugin; APNs token on iOS, FCM token on Android | @capacitor/push-notifications |
| FCM token on both platforms, topics, Firebase-first backend | @capgo/capacitor-firebase-messaging |
| Capgo-managed delivery (dashboard campaigns, badges, silent live-update checks, no own push server) | @capgo/capacitor-notifications |
| Local notifications only, rich layouts | @capgo/capacitor-rich-notifications or @capacitor/local-notifications |
The rest of this file covers @capacitor/push-notifications. For Capgo plugins follow https://capgo.app/docs/plugins/firebase-messaging/ or https://capgo.app/docs/plugins/notifications/getting-started/.
Workflow
- Inspect:
package.jsonversions (@capacitor/core,@capacitor/push-notifications),capacitor.config.*plugins.PushNotifications,ios/App/App/AppDelegate.swift,ios/App/App/*.entitlements,android/app/google-services.json,android/variables.gradle,AndroidManifest.xml. - Install:
npm install @capacitor/push-notifications && npx cap sync. - iOS: capability + APNs key + AppDelegate forwarding. Details: references/ios-setup.md.
- Android:
google-services.json, channel, icon, permission. Details: references/android-setup.md. - JS: listeners first, then permission, then
register()(below). - Backend: send a test message. Payload shapes: references/sending.md.
- Verify with the checklist below on physical devices.
Only load a reference when its topic is in play.
JS registration (order matters)
import { PushNotifications } from '@capacitor/push-notifications';
export async function initPush() {
// 1. Listeners before register(), or the first token is missed
await PushNotifications.addListener('registration', ({ value }) => sendTokenToServer(value));
await PushNotifications.addListener('registrationError', (err) => console.error('push reg', err.error));
await PushNotifications.addListener('pushNotificationReceived', (n) => {
// foreground only (and Android data-only while app is alive)
});
await PushNotifications.addListener('pushNotificationActionPerformed', ({ notification, actionId }) => {
routeFromNotification(notification.data); // tap handling
});
// 2. Permission (required on iOS and Android 13+ / targetSdk 33+)
let perm = await PushNotifications.checkPermissions();
if (perm.receive === 'prompt' || perm.receive === 'prompt-with-rationale') {
perm = await PushNotifications.requestPermissions();
}
if (perm.receive !== 'granted') return; // explain + link to settings, do not loop prompts
// 3. Register
await PushNotifications.register();
}
Traps:
- Call
initPush()at bootstrap sopushNotificationActionPerformedfrom a cold-start tap is captured. - Tokens rotate. Send every
registrationvalue to the server and upsert by user + device. - On iOS the plugin reports the raw APNs token unless AppDelegate swaps in the FCM token (see ios-setup). Sending an APNs token to FCM fails with
messaging/invalid-registration-token. - Ask permission after a user action that explains the value; iOS shows the system prompt only once.
Foreground presentation
// capacitor.config.ts
plugins: {
PushNotifications: {
presentationOptions: ['badge', 'sound', 'banner', 'list'],
},
},
banner+listreplace the deprecated iOSalert. Capacitor 9 removesalerton iOS; replace it when upgrading.badgeis iOS only.- Empty array = nothing shown in foreground; handle
pushNotificationReceivedyourself.
Capacitor version notes
| Version | Change |
|---|---|
| 7 | firebaseMessagingVersion default 24.1.0 |
| 8 | firebaseMessagingVersion default 25.0.1 |
| 8.5 | UIScene lifecycle. Remote-notification callbacks (didRegisterForRemoteNotificationsWithDeviceToken, didFailToRegister...) stay in AppDelegate and keep working. Do not move them to SceneDelegate. Tap routing that used AppDelegate application(_:open:) must move (see capacitor-deep-linking). |
| 9 | iOS alert presentation option removed; iOS 16 min; @main replaces @UIApplicationMain; google-services Gradle plugin 4.5.0 |
Verification
- iOS:
codesign -d --entitlements :- path/to/App.app | grep aps-environmentshowsdevelopment(debug) orproduction(TestFlight/App Store). - Android:
adb shell dumpsys package com.example.app | grep POST_NOTIFICATIONSshowsgranted=trueafter accepting the prompt. - App logs a
registrationtoken on a real device (iOS Simulator on Apple silicon can receive pushes viaxcrun simctl push, but test real APNs on device). - Send a test from Firebase Console (Messaging -> "Send test message") or your backend to that token.
- Check all three states: foreground (presentation +
pushNotificationReceived), background (system tray), killed (tap ->pushNotificationActionPerformedroutes correctly). - iOS simulator smoke test without a server:
cat > /tmp/push.apns <<'EOF'
{ "Simulator Target Bundle": "com.example.app", "aps": { "alert": { "title": "Test", "body": "Hello" } }, "route": "/inbox" }
EOF
xcrun simctl push booted com.example.app /tmp/push.apns
(aps.alert in the APNs payload is the message content and is unaffected by the presentationOptions change.)
Error Handling
| Error / symptom | Cause | Fix |
|---|---|---|
no valid "aps-environment" entitlement string found for application | Push Notifications capability missing or profile not regenerated | Add capability in Xcode, re-sign, rebuild |
registration never fires on iOS, no error | AppDelegate does not post .capacitorDidRegisterForRemoteNotifications | Add forwarding methods to AppDelegate |
Default FirebaseApp is not initialized in this process (Android) | google-services.json missing/empty, so google-services plugin was not applied (google-services.json not found, google-services plugin not applied. Push Notifications won't work) | Put file in android/app/, rebuild |
messaging/registration-token-not-registered | Token stale (app reinstalled / data cleared) | Delete token server-side; rely on next registration |
messaging/invalid-registration-token / BadDeviceToken | APNs token sent to FCM, or sandbox token sent to production APNs | Use FCM token on iOS (ios-setup) or match APNs environment |
messaging/third-party-auth-error | APNs key not uploaded to Firebase, wrong Key ID / Team ID | Upload .p8 under Firebase Project Settings -> Cloud Messaging |
| Android 13+: nothing shown, no prompt | requestPermissions() never called | Call it; manifest permission is added by the plugin |
| Android shows white square icon | No monochrome notification icon | Set default_notification_icon meta-data |
| Android notification silent / wrong importance | Channel created with low importance (importance is immutable after creation) | Create a new channel id; delete the old one |
| Data-only message ignored when app killed (Android) | Plugin only delivers while app process lives | Native FirebaseMessagingService (android-setup) |
| iOS silent / background push not delivered to JS | Plugin does not support iOS silent push | Native handling, or @capgo/capacitor-notifications silent update checks |
| Duplicate class errors with Firebase after Capacitor 9 | Old core-ktx / Kotlin stdlib pins | See capacitor-app-upgrade-v8-to-v9 |
Resources
- Plugin API: https://capacitorjs.com/docs/apis/push-notifications
- Firebase guide: https://capacitorjs.com/docs/guides/push-notifications-firebase
- Updating to 9.0: https://capacitorjs.com/docs/updating/9-0
- Capgo Firebase Messaging: https://capgo.app/docs/plugins/firebase-messaging/
- Capgo Notifications: https://capgo.app/docs/plugins/notifications/
How can the creator link this skill?
Add the canonical catalog link to the repository README so users can inspect current installs and available audits. The publishing guide covers the complete discovery path.
<a href="https://skillzs.dev/skills/cap-go/capgo-skills/capacitor-push-notifications">View capacitor-push-notifications on skillZs</a>