web-push


Why

Web push requires that push messages triggered from a backend be done via the
Web Push Protocol
and if you want to send data with your push message, you must also encrypt
that data according to the Message Encryption for Web Push spec.

This module makes it easy to send messages and will also handle legacy support
for browsers relying on GCM for message sending / delivery.

Install

Installation is simple, just install via npm.

npm install web-push --save

Usage

The common use case for this library is an application server using
a GCM API key and VAPID keys.

``javascript
const webpush = require('web-push');

// VAPID keys should be generated only once.
const vapidKeys = webpush.generateVAPIDKeys();

webpush.setGCMAPIKey('');
webpush.setVapidDetails(
'mailto:example@yourdomain.org',
vapidKeys.publicKey,
vapidKeys.privateKey
);

// This is the same output of calling JSON.stringify on a PushSubscription
const pushSubscription = {
endpoint: '.....',
keys: {
auth: '.....',
p256dh: '.....'
}
};

webpush.sendNotification(pushSubscription, 'Your Push Payload Text');
`

Using VAPID Key for applicationServerKey

When subscribing to push messages, you'll need to pass your VAPID key,
which you can do like so:

`javascript
registration.pushManager.subscribe({
userVisibleOnly: true,
applicationServerKey: ''
});
`

Command Line

You can install web-push globally and use it for sending notifications
and / or generating VAPID keys.

Install like so:

npm install web-push -g

Then you can run the following commands:

Usage:

web-push send-notification --endpoint= [--key=] [--auth=] [--payload=] [--encoding=] [--ttl=] [--vapid-subject=] [--vapid-pubkey=] [--vapid-pvtkey=] [--proxy=] [--gcm-api-key=]

web-push generate-vapid-keys [--json]

Example of send notification:
`shell
> web-push generate-vapid-keys --json
> {"publicKey":"BGtkbcjrO12YMoDuq2sCQeHlu47uPx3SHTgFKZFYiBW8Qr0D9vgyZSZPdw6_4ZFEI9Snk1VEAj2qTYI1I1YxBXE","privateKey":"I0_d0vnesxbBSUmlDdOKibGo6vEXRO-Vu88QlSlm5j0"}
`
The subscription value:
`javascript
{
"endpoint": "https://fcm.googleapis.com/fcm/send/d61c5u920dw:APA91bEmnw8utjDYCqSRplFMVCzQMg9e5XxpYajvh37mv2QIlISdasBFLbFca9ZZ4Uqcya0ck-SP84YJUEnWsVr3mwYfaDB7vGtsDQuEpfDdcIqOX_wrCRkBW2NDWRZ9qUz9hSgtI3sY",
"expirationTime": null,
"keys": {
"p256dh": "BL7ELU24fJTAlH5Kyl8N6BDCac8u8li_U5PIwG963MOvdYs9s7LSzj8x_7v7RFdLZ9Eap50PiiyF5K0TDAis7t0",
"auth": "juarI8x__VnHvsOgfeAPHg"
}
}
`
The command example:
`shell
web-push send-notification \
--endpoint=https://fcm.googleapis.com/fcm/send/d61c5u920dw:APA91bEmnw8utjDYCqSRplFMVCzQMg9e5XxpYajvh37mv2QIlISdasBFLbFca9ZZ4Uqcya0ck-SP84YJUEnWsVr3mwYfaDB7vGtsDQuEpfDdcIqOX_wrCRkBW2NDWRZ9qUz9hSgtI3sY \
--key=BL7ELU24fJTAlH5Kyl8N6BDCac8u8li_U5PIwG963MOvdYs9s7LSzj8x_7v7RFdLZ9Eap50PiiyF5K0TDAis7t0 \
--auth=juarI8x__VnHvsOgfeAPHg \
--vapid-subject=mailto:example@qq.com \
--vapid-pubkey=BGtkbcjrO12YMoDuq2sCQeHlu47uPx3SHTgFKZFYiBW8Qr0D9vgyZSZPdw6_4ZFEI9Snk1VEAj2qTYI1I1YxBXE \
--vapid-pvtkey=I0_d0vnesxbBSUmlDdOKibGo6vEXRO-Vu88QlSlm5j0 \
--payload=Hello
`

API Reference

sendNotification(pushSubscription, payload, options)

`javascript
const pushSubscription = {
endpoint: '< Push Subscription URL >',
keys: {
p256dh: '< User Public Encryption Key >',
auth: '< User Auth Secret >'
}
};

const payload = '< Push Payload String >';

const options = {
gcmAPIKey: '< GCM API Key >',
vapidDetails: {
subject: '< \'mailto\' Address or URL >',
publicKey: '< URL Safe Base64 Encoded Public Key >',
privateKey: '< URL Safe Base64 Encoded Private Key >'
},
timeout:
TTL: ,
headers: {
'< header name >': '< header value >'
},
contentEncoding: '< Encoding type, e.g.: aesgcm or aes128gcm >',
urgency:'< Default is "normal" >',
topic:'< Use a maximum of 32 characters from the URL or filename-safe Base64 characters sets. >',

proxy: '< proxy server options >',
agent: '< https.Agent instance >'
}

webpush.sendNotification(
pushSubscription,
payload,
options
);
`

> Note: sendNotification() you don't need to define a payload, and this
method will work without a GCM API Key and / or VAPID keys if the push service
supports it.

$3

Push Subscription

The first argument must be an object containing the details for a push
subscription.

The expected format is the same output as JSON.stringify'ing a PushSubscription
in the browser.

Payload

The payload is optional, but if set, will be the data sent with a push
message.

This must be either a string or a node
Buffer.

> Note: In order to encrypt the payload, the pushSubscription must
have a keys object with p256dh and auth values.

Options

Options is an optional argument that if defined should be an object containing
any of the following values defined, although none of them are required.

- gcmAPIKey can be a GCM API key to be used for this request and this
request only. This overrides any API key set via setGCMAPIKey().
- vapidDetails should be an object with subject, publicKey and
privateKey values defined. These values should follow the VAPID Spec.
- timeout is a value in milliseconds that specifies the request's socket timeout. On timeout, the request will be destroyed and the promise will be rejected with a meaningful error. It's a common misconception that a socket timeout is the timeout to receive the full response. So if you have a socket timeout of 1 second, and a response comprised of 3 TCP packets, where each response packet takes 0.9 seconds to arrive, for a total response time of 2.7 seconds, then there will be no timeout. Once a socket 'timeout' triggers the request will be aborted by the library (by default undefined).
- TTL is a value in seconds that describes how long a push message is
retained by the push service (by default, four weeks).
- headers is an object with all the extra headers you want to add to the request.
- contentEncoding is the type of push encoding to use (e.g. 'aes128gcm', by default, or 'aesgcm').
- urgency is to indicate to the push service whether to send the notification immediately or prioritize the recipient’s device power considerations for delivery. Provide one of the following values: very-low, low, normal, or high. To attempt to deliver the notification immediately, specify high.
- topic optionally provide an identifier that the push service uses to coalesce notifications. Use a maximum of 32 characters from the URL or filename-safe Base64 characters sets.
- proxy is the HttpsProxyAgent's constructor argument
that may either be a string URI of the proxy server (eg. http://< hostname >:< port >)
or an "options" object with more specific properties.
- agent is the HTTPS Agent instance which will be used in the https.request method. If the proxy options defined, agent will be ignored!

> Note: As of this writing, if a push notification request contains a VAPID subject referencing an https://localhost URI (set either using the options argument or via the global setVapidDetails() method), Safari's push notification endpoint rejects the request with a BadJwtToken error.

$3

A promise that resolves if the notification was sent successfully
with details of the request, otherwise it rejects.

In both cases, resolving or rejecting, you'll be able to access the following
values on the returned object or error.

- statusCode, the status code of the response from the push service;
- headers, the headers of the response from the push service;
- body, the body of the response from the push service.

generateVAPIDKeys()

`javascript
const vapidKeys = webpush.generateVAPIDKeys();

// Prints 2 URL Safe Base64 Encoded Strings
console.log(vapidKeys.publicKey, vapidKeys.privateKey);
`

$3

None.

$3

Returns an object with publicKey and privateKey values which are
URL Safe Base64 encoded strings.

> Note: You should create these keys once, store them and use them for all
> future messages you send.

setGCMAPIKey(apiKey)

`javascript
webpush.setGCMAPIKey('Your GCM API Key');
`

$3

This method expects the GCM API key that is linked to the gcm_sender_id in
your web app manifest.

You can use a GCM API Key from the Google Developer Console or the
Cloud Messaging tab under a Firebase Project.

$3

None.

setVapidDetails(subject, publicKey, privateKey)

`javascript
webpush.setVapidDetails(
'mailto:user@example.org',
process.env.VAPID_PUBLIC_KEY,
process.env.VAPID_PRIVATE_KEY
);
`

Globally sets the application's VAPID subject, public key, and private key, to be used in subsequent calls to sendNotification() and generateRequestDetails() that don't specifically override them in their options argument.

$3

The setVapidDetails method expects the following input:

- subject: the VAPID server contact information, as either an https: or mailto: URI (as per the VAPID spec).
- publicKey: the VAPID public key.
- privateKey: the VAPID private key.

$3

None.

encrypt(userPublicKey, userAuth, payload, contentEncoding)

`javascript
const pushSubscription = {
endpoint: 'https://....',
keys: {
p256dh: '.....',
auth: '.....'
}
};
webPush.encrypt(
pushSubscription.keys.p256dh,
pushSubscription.keys.auth,
'My Payload',
'aes128gcm'
)
.then(encryptionDetails => {

});
`

Encrypts the payload according to the Message Encryption for Web
Push standard.

> (sendNotification will automatically encrypt the payload for you, so if
> you use sendNotification you don't need to worry about it).

$3

The encrypt() method expects the following input:

- userPublicKey: the public key of the receiver (from the browser).
- userAuth: the auth secret of the receiver (from the browser).
- payload: the message to attach to the notification.
- contentEncoding: the type of content encoding to use (e.g. aesgcm or aes128gcm).

$3

This method returns an object with the following fields:

- localPublicKey: The public key matched the private key used during
encryption.
- salt: A string representing the salt used to encrypt the payload.
- cipherText: The encrypted payload as a Buffer.

getVapidHeaders(audience, subject, publicKey, privateKey, contentEncoding, expiration)

`javascript
const parsedUrl = url.parse(subscription.endpoint);
const audience = parsedUrl.protocol + '//' +
parsedUrl.hostname;

const vapidHeaders = vapidHelper.getVapidHeaders(
audience,
'mailto: example@web-push-node.org',
vapidDetails.publicKey,
vapidDetails.privateKey,
'aes128gcm'
);
`

The getVapidHeaders() method will take in the values needed to create
an Authorization and Crypto-Key header.

$3

The getVapidHeaders() method expects the following input:

- audience: the origin of the push service.
- subject: the mailto or URL for your application.
- publicKey: the VAPID public key.
- privateKey: the VAPID private key.
- contentEncoding: the type of content encoding to use (e.g. aesgcm or aes128gcm).

$3

This method returns an object with the following fields:

- localPublicKey: The public key matched the private key used during
encryption.
- salt: A string representing the salt used to encrypt the payload.
- cipherText: The encrypted payload as a Buffer.

generateRequestDetails(pushSubscription, payload, options)

`javascript
const pushSubscription = {
endpoint: '< Push Subscription URL >';
keys: {
p256dh: '< User Public Encryption Key >',
auth: '< User Auth Secret >'
}
};

const payload = '< Push Payload String >';

const options = {
gcmAPIKey: '< GCM API Key >',
vapidDetails: {
subject: '< \'mailto\' Address or URL >',
publicKey: '< URL Safe Base64 Encoded Public Key >',
privateKey: '< URL Safe Base64 Encoded Private Key >',
}
TTL: ,
headers: {
'< header name >': '< header value >'
},
contentEncoding: '< Encoding type, e.g.: aesgcm or aes128gcm >',
urgency:'< Default is normal "Defult" >',
topic:'< Use a maximum of 32 characters from the URL or filename-safe Base64 characters sets. >',
proxy: '< proxy server options >'
}

try {
const details = webpush.generateRequestDetails(
pushSubscription,
payload,
options
);
} catch (err) {
console.error(err);
}
`

> Note: When calling generateRequestDetails() the payload argument
does not need to be defined, passing in null will return no body and
> exclude any unnecessary headers.
> Headers related to the GCM API Key and / or VAPID keys will be included
> if supplied and required.

$3

Push Subscription

The first argument must be an object containing the details for a push
subscription.

The expected format is the same output as JSON.stringify'ing a PushSubscription
in the browser.

Payload

The payload is optional, but if set, will be encrypted and a Buffer
will be returned via the payload parameter.

This argument must be either a string or a node
Buffer.

> Note: In order to encrypt the payload, the pushSubscription must
have a keys object with p256dh and auth values.

Options

Options is an optional argument that if defined should be an object containing
any of the following values defined, although none of them are required.

- gcmAPIKey can be a GCM API key to be used for this request and this
request only. This overrides any API key set via setGCMAPIKey().
- vapidDetails should be an object with subject, publicKey and
privateKey values defined. These values should follow the VAPID Spec.
- TTL is a value in seconds that describes how long a push message is
retained by the push service (by default, four weeks).
- headers is an object with all the extra headers you want to add to the request.
- contentEncoding is the type of push encoding to use (e.g. 'aesgcm', by default, or 'aes128gcm').
- urgency is to indicate to the push service whether to send the notification immediately or prioritize the recipient’s device power considerations for delivery. Provide one of the following values: very-low, low, normal, or high. To attempt to deliver the notification immediately, specify high.
- topic optionally provide an identifier that the push service uses to coalesce notifications. Use a maximum of 32 characters from the URL or filename-safe Base64 characters sets.
- proxy is the HttpsProxyAgent's constructor argument
that may either be a string URI of the proxy server (eg. http://< hostname >:< port >)
or an "options" object with more specific properties.

$3

An object containing all the details needed to make a network request, the
object will contain:

- endpoint, the URL to send the request to;
- method, this will be 'POST';
- headers, the headers to add to the request;
- body, the body of the request (As a Node Buffer).

Browser Support

Help

MDN

There's an example on MDN.

Also, the Service Worker Cookbook is full of Web Push
examples using this library.

Running tests

> Prerequisites:
> * Java JDK or JRE (http://www.oracle.com/technetwork/java/javase/downloads/index.html)

To run tests:

npm test