# Sending Push Messages Load when writing backend code or a test sender. ## FCM HTTP v1 (Firebase Admin SDK, Node) ```ts import { initializeApp, cert } from 'firebase-admin/app'; import { getMessaging } from 'firebase-admin/messaging'; initializeApp({ credential: cert(serviceAccountJson) }); await getMessaging().send({ token, notification: { title: 'New message', body: 'Open to read' }, data: { route: '/inbox/42' }, // strings only android: { priority: 'high', notification: { channelId: 'messages' } }, apns: { payload: { aps: { sound: 'default', badge: 1 } } }, }); ``` - Legacy FCM server-key API (`https://fcm.googleapis.com/fcm/send`, `"to": ...`) is shut down; use HTTP v1 (`/v1/projects/<id>/messages:send`) with an OAuth access token from a service account. - `data` values must be strings. Read them in JS from `notification.data`. - Multicast: `sendEachForMulticast({ tokens, ... })` (max 500 tokens per call). Remove tokens that return `messaging/registration-token-not-registered`. - Topics: `subscribeToTopic` is server-side in Admin SDK, or client-side with `@capgo/capacitor-firebase-messaging`. ## Direct APNs Only if `registration` returns raw APNs tokens. Use token-based auth (`.p8`, JWT signed ES256 with Key ID + Team ID), `apns-topic` = bundle ID, `apns-push-type: alert`. Sandbox host `api.sandbox.push.apple.com`, production `api.push.apple.com`. ## Tap routing payload Put the route in `data.route` (FCM) or a custom top-level key (APNs). In `pushNotificationActionPerformed`, validate against an allow-list before navigating. ## Capgo-managed `@capgo/capacitor-notifications` sends from the Capgo dashboard / API without your own FCM/APNs sender. See https://capgo.app/docs/plugins/notifications/getting-started/.