The subscribe() method of the CookieStoreManager interface subscribes a ServiceWorkerRegistration to cookie change events.

subscriptions

An object containing:

name

A string with the name of a cookie.

url

A string with the url of a cookie scope. This may be narrower than the scope of the service worker registration.

A Promise that resolves with undefined when the subscription completes.

TypeError

Thrown if the URL passed in subscriptions does not match the service worker registration's scope.

In this example the ServiceWorkerRegistration represented by registration is subscribing to change events on the cookie named "cookie1" with a scope of "/path1".

const subscriptions = [{ name: "cookie1", url: `/path1` }];
await registration.cookies.subscribe(subscriptions);

The URL passed to the subscribe() method, may be narrower than the service worker registration scope. In the following example the subscription is for /path/one/, so it will receive change events for changes on the first cookie, but not the second.

registration.cookies.subscribe([{ name: "cookie1", url: "/path/one/" }]); // subscription
cookieStore.set({ name: "cookie1", value: "cookie-value", path: "/path/one/" }); // receives a change event
cookieStore.set({ name: "cookie1", value: "cookie-value", path: "/path/two/" }); // does not receive a change event