Use the current APNs and FCM interfaces

How to do it

For APNs, sign a JWT with your .p8 key using ES256. Reuse it for 20 to 60 minutes, because APNs rejects older tokens and answers 429 to tokens changed too often. Share one token across servers. Set apns-push-type and apns-topic on every request. For FCM, get an OAuth 2.0 access token from a service account and POST to /v1/projects/<project>/messages:send. Google shut down the legacy FCM API in 2024. A provider such as Amazon SNS or OneSignal can wrap both.

Example

import { SignJWT, importPKCS8 } from 'jose';

const TOKEN_LIFETIME_MS = 30 * 60 * 1000;
let cached = { token: '', madeAt: 0 };

export async function apnsToken() {
  if (Date.now() - cached.madeAt < TOKEN_LIFETIME_MS) return cached.token;
  const key = await importPKCS8(process.env.APNS_KEY_P8, 'ES256');
  const token = await new SignJWT({}).setProtectedHeader({ alg: 'ES256', kid: process.env.APNS_KEY_ID })
    .setIssuer(process.env.APPLE_TEAM_ID).setIssuedAt().sign(key);
  cached = { token, madeAt: Date.now() };
  return token;
}

import google.auth.transport.requests
import requests
from google.oauth2 import service_account

SCOPES = ["https://www.googleapis.com/auth/firebase.messaging"]
credentials = service_account.Credentials.from_service_account_file("fcm-service-account.json", scopes=SCOPES)

def send_fcm(token: str, title: str, body: str):
    credentials.refresh(google.auth.transport.requests.Request())
    return requests.post(
        "https://fcm.googleapis.com/v1/projects/example-shop/messages:send",
        headers={"Authorization": f"Bearer {credentials.token}"},
        json={"message": {"token": token, "notification": {"title": title, "body": body}}},
        timeout=10,
    )

How to check

Grep the code for fcm.googleapis.com/fcm/send and for certificate-based APNs settings. Neither appears. A staging send to one iOS and one Android device succeeds.