← Blog · July 30, 2026

BYO-Firebase push notifications explained: what it means, what it costs, and why delivery is free

Firebase Cloud Messaging has always been free for delivery — Google charges nothing per message sent. What costs money in a push notification stack is not the delivery, it is everything around it: storing device tokens, building the send API, managing audiences, scheduling, analytics, and keeping the integration working as FCM evolves. "Bring your own Firebase" (BYO-Firebase) is a model where a third-party service handles all of that management infrastructure while you supply the FCM credentials from your own Google project.

What you actually own

In a BYO-Firebase setup, your Google Cloud project holds the Firebase service account — the private key that authorizes calls to the FCM v1 API. The push notification service receives that service account from you (encrypted at rest), authenticates with your Firebase project, and sends on your behalf. Key implications:

  • Delivery goes through your project quota, not a shared pool.
  • Firebase Analytics, Crashlytics, and other Firebase products stay under your Google account.
  • You can revoke the service account at any time to cut off third-party access, with no dependency on the vendor to rotate credentials.
  • If you move to a different push service later, your token database is portable — the tokens are tied to your Firebase project, not the vendor.

What the service provides

The BYO-Firebase service abstracts the operational work: chunking sends into batches of up to 500 tokens (the FCM multicast limit), pruning invalid tokens on each send, handling retries, storing device registration data, running a scheduler, and providing an HTTP API so you do not write any of that yourself. You get a dashboard and send API; Firebase handles the actual message delivery to the device.

Pushbrain is a BYO-Firebase service. You upload your Firebase service account JSON once, it is encrypted with AES-256-GCM and stored per-app, and every send goes out under your project FCM credentials. The monthly cost covers the management layer; delivery is always free at the FCM level.