Hi everyone.
I’m working on an iOS app that uses Firebase Cloud Messaging (FCM) to send push notifications. I’m encountering an issue when trying to send notifications either from Firebase Functions or directly using the FCM token with the Firebase Admin SDK and REST API.
Error Message:
FirebaseMessagingError: Auth error from APNS or Web Push Service code: 'messaging/third-party-auth-error' message: 'Auth error from APNS or Web Push Service'
What I’ve Set Up:
- iOS App Registered in Firebase
- Bundle ID: Kilovative-Designs.ParkAware
- APNs Key downloaded from Apple Developer Portal
- Team ID and Key ID correctly entered in Firebase Console
- Firebase Admin SDK Service Account setup and used for sending
- Device is successfully receiving FCM tokens
- Subscribed to topics and calling Messaging.messaging().subscribe(toTopic:) works
- Using firebase-admin to send FCM messages via sendToDevice or sendToTopic
What I’ve Tried:
- Tested push via firebase-admin in Node.js (got same APNs auth error)
- Tested with both topic-based and direct token-based push
- Confirmed the .p8 key is uploaded in Firebase, with correct Key ID and Team ID
- Tried generating a new APNs Auth Key
- Firebase Admin SDK is initialized with the correct service account
Using Node.js firebase-admin with a known good FCM token, and sending this payload:
{ notification: { title: "Test Notification", body: "This is a direct FCM test" }, token: "cxleOwi73EhFh9C5_V4hED:APA91bE3W..." }
Returns: FirebaseMessagingError: Auth error from APNS or Web Push Service
Questions:
- Are there known conditions under which Firebase throws this error even if the APNs Auth Key is present?
- Does the Bundle ID need to start with com. in the Apple Developer Portal and Firebase for APNs authentication to work?
- Could this be a certificate or provisioning profile mismatch issue (even when using a .p8 key)?
- Is there a way to manually validate APNs authentication from Firebase outside of actual push delivery?
Any insight or guidance would be incredibly helpful. I’m new to developing and have tried repeated efforts to fix this issue but still haven’t resolved it.
Thanks in advance!