fcm-http2

fcm-http2

Library in typescript for sending multicast notifications using HTTP/2 multiplexing and the FCM HTTP v1 API.

Features supported by fcm-http2:

• HTTP/2 session & stream concurrency
• Token batching support
• Uninstall detection
• Retry mechanism

Requirements

• Node.js >= 18
• Deno >= 2.4

Installation

For NodeJS applications, installation is done as follows:

npm install fcm-http2

For Deno applications, installation is as follows:

import { FCM } from 'https://esm.sh/fcm-http2';

Usage

Once the library has been installed you can start using it in this way.

How to create the FCM object?

CommonJS & ESM

Option for CommonJS with file:

// FCM library recovery
const FCM = require('fcm-http2').FCM;

// Basic configuration for FCM
const fcmOptions = {
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    serviceAccount: require('./service-account.json'),
    // Max number of concurrent HTTP/2 sessions (connections)
    maxConcurrentConnections: 10,
    // Max number of concurrent streams (requests) per session
    maxConcurrentStreamsAllowed: 100
};

// Init FCM with options
const fcmClient = new FCM(fcmOptions);

Option for ESM (JavaScript/TypeScript) with file:

// FCM library recovery
import { FCM, FcmBaseOptions } from 'fcm-http2';

// Basic configuration for FCM
const fcmOptions: FcmBaseOptions = {
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    serviceAccount: require('./service-account.json'),
    // Max number of concurrent HTTP/2 sessions (connections)
    maxConcurrentConnections: 10,
    // Max number of concurrent streams (requests) per session
    maxConcurrentStreamsAllowed: 100
};

// Init FCM with options
const fcmClient = new FCM(fcmOptions);

Option for CommonJS without file:

// FCM library recovery
const FCM = require('fcm-http2').FCM;

// Basic configuration for FCM
const fcmOptions = {
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    // NOTE: Recover the three parameters from the service-account.json file
    serviceAccount: {
        project_id: '<project_id>',
        private_key: '<private_key>',
        client_email: '<client_email>'
    },
    // Max number of concurrent HTTP/2 sessions (connections)
    maxConcurrentConnections: 10,
    // Max number of concurrent streams (requests) per session
    maxConcurrentStreamsAllowed: 100
};

// Init FCM with options
const fcmClient = new FCM(fcmOptions);

Option for ESM (JavaScript/TypeScript) without file:

// FCM library recovery
import { FCM, FcmBaseOptions } from 'fcm-http2';

// Basic configuration for FCM
const fcmOptions: FcmBaseOptions = {
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    // NOTE: Recover the three parameters from the service-account.json file
    serviceAccount: {
        project_id: '<project_id>',
        private_key: '<private_key>',
        client_email: '<client_email>'
    },
    // Max number of concurrent HTTP/2 sessions (connections)
    maxConcurrentConnections: 10,
    // Max number of concurrent streams (requests) per session
    maxConcurrentStreamsAllowed: 100
};

// Init FCM with options
const fcmClient = new FCM(fcmOptions);

Deno

Only option:

// FCM library recovery
import { FCM, FcmBaseOptions } from 'https://esm.sh/fcm-http2';

// Basic configuration for FCM
const fcmOptions: FcmBaseOptions = {
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    // NOTE: Recover the three parameters from the service-account.json file
    serviceAccount: {
        project_id: '<project_id>',
        private_key: '<private_key>',
        client_email: '<client_email>'
    },
    // Max number of concurrent HTTP/2 sessions (connections)
    maxConcurrentConnections: 10,
    // Max number of concurrent streams (requests) per session
    maxConcurrentStreamsAllowed: 100
};

// Init FCM with options
const fcmClient = new FCM(fcmOptions);

Send multicast

// NOTE: Use the fcmClient object that you created earlier

// Token to send the notification to
const tokens = ['TOKEN_1', 'TOKEN_N'];

// Composing the message to be sent
const message = {
    notification: {
        title: "Test",
        body: "Multiple Send"
    },
    data: {
        notification: "true"
    }
};

// Multiple sending of notification using token array
fcmClient.sendMulticast(message, tokens).then((unregisteredTokens: Array<string>) => {

    // Sending successful
    console.log('Message sent successfully');

    // Remove unregistered tokens from your database
    if (unregisteredTokens.length > 0) {
        console.log('Unregistered device token(s): ', unregisteredTokens.join(', '));
    }

}).catch((error: object) => console.log(error));

License

Apache License 2.0

Support

For any doubts open an issue or contact this email [e-mail]

Changelog

2.7.0 (2025-12-24)

IMPORTANT: The minimum NodeJS version is now 18

Features

• Implemented logic to request an access token via Google APIs without the googleapis nodejs library by @fctaddia
• Googleapis dependency removed because no longer used by @fctaddia

Performance improvements

• Updated dependencies by @fctaddia
  @types/node -> 25.0.3

Bug fixes

• Code cleaning by @fctaddia