> ## Documentation Index
> Fetch the complete documentation index at: https://docs.horizonmanaged.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Notifications

> Browser push notifications (Web Push) so you get native alerts from NEXOS CORE even when the tab isn't focused

NEXOS CORE can send **browser push notifications** using Web Push (VAPID), so you
get native desktop/mobile alerts even when the NEXOS CORE tab isn't focused.
Subscriptions are stored per user (per browser), and signing keys are held per
tenant.

## When to use it

* Get notified of things that need attention — like a purchase-order approval
  request — without watching the app.
* Opt a browser in to push notifications.
* Opt a browser back out (unsubscribe) on a shared or retired device.

## How it works

<Steps>
  <Step title="Subscribe your browser">
    Your browser fetches the tenant's public VAPID key and registers a push
    subscription; NEXOS CORE stores the endpoint and keys against your user.
  </Step>

  <Step title="NEXOS CORE delivers">
    When an event fires (e.g. a PO approval), NEXOS CORE pushes to all of your
    subscribed browsers. Notifications arrive even with the tab in the background.
  </Step>

  <Step title="Cleanup is automatic">
    Subscriptions a browser has revoked are detected and removed automatically.
  </Step>
</Steps>

The tenant's VAPID keypair is generated automatically the first time it's needed.

## Good to know

* **Push is opt-in per browser** — you won't receive notifications until you
  subscribe, and you subscribe separately on each device/browser.
* Requires a browser that supports the Web Push API and service workers
  (Chrome/Edge/Firefox; Safari requires a recent macOS/iOS with the app installed
  as a PWA).
* Delivery is best-effort — a failed push is logged and retried on the next event,
  not surfaced as an error.