PushManager: subscribe() method

Secure contextAvailable in workers

The subscribe() method of the PushManager interface subscribes to a push service.

It returns a Promise that resolves to a PushSubscription object containing details of a push subscription. A new push subscription is created if the current service worker does not have an existing subscription.

Syntax

subscribe(options)

Parameters

• options Optional

  • : An object containing optional configuration parameters. It can have the following properties:

    • userVisibleOnly
      • : A boolean indicating that the returned push subscription will only be used for messages whose effect is made visible to the user.
    • applicationServerKey
      • : A Base64-encoded string or ArrayBuffer containing an ECDSA P-256 public key that the push server will use to authenticate your application server. If specified, all messages from your application server must use the VAPID authentication scheme, and include a JWT signed with the corresponding private key. This key IS NOT the same ECDH key that you use to encrypt the data. For more information, see “Using VAPID with WebPush”.

    [!NOTE] This parameter is required in some browsers like Chrome and Edge. They will reject the Promise if userVisibleOnly is not set to true.

Return value

A Promise that resolves to a PushSubscription object.

Examples

this.onpush = (event) => {
  console.log(event.data);
  // From here we can write the data to IndexedDB, send it to any open
  // windows, display a notification, etc.
};

navigator.serviceWorker.register("serviceworker.js");

// Use serviceWorker.ready to ensure that you can subscribe for push
navigator.serviceWorker.ready.then((serviceWorkerRegistration) => {
  const options = {
    userVisibleOnly: true,
    applicationServerKey,
  };
  serviceWorkerRegistration.pushManager.subscribe(options).then(
    (pushSubscription) => {
      console.log(pushSubscription.endpoint);
      // The push subscription details needed by the application
      // server are now available, and can be sent to it using,
      // for example, the fetch() API.
    },
    (error) => {
      // During development it often helps to log errors to the
      // console. In a production environment it might make sense to
      // also report information about errors back to the
      // application server.
      console.error(error);
    },
  );
});

Responding to user gestures

subscribe() calls should be done in response to a user gesture, such as clicking a button, for example:

btn.addEventListener("click", () => {
  serviceWorkerRegistration.pushManager
    .subscribe(options)
    .then((pushSubscription) => {
      // handle subscription
    });
});

This is not only best practice — you should not be spamming users with notifications they didn’t agree to — but going forward browsers will explicitly disallow notifications not triggered in response to a user gesture. Firefox is already doing this from version 72, for example.

Specifications

Browser compatibility