Alarm

A simple alarm clock web app that can sync your alarms across devices via your own Solid pod.

Features

Large clock showing the date, time and seconds, with a chip for the next alarm and how long until it rings.
Quick alarms: 1 min, 5 min, 10 min, 30 min and 1 hour. These ring once and are removed when you press Stop.
New alarm: pick hour, minute (in 5-minute steps) and AM/PM, add an optional label (up to 40 characters) and set it. These repeat daily.
Six synthesized tones (Web Audio, no audio files): Beep, Bell, Chime (default), Gentle, Digital and Siren, with a Preview button.
While ringing: Snooze (9 minutes), Stop, or Delete.
Toggle switch to enable or disable each alarm; alarms are listed by time.
Optional browser notifications when an alarm rings (an Enable prompt is shown if permission hasn't been decided).
Sign in with Solid through xlogin.
Web app manifest with icons, so it can be added to a home screen.

Alarms only ring while the page is open in a browser tab; the app checks them every second and again when the tab becomes visible.

Signed out: alarms are stored in the browser's localStorage under the key alarms. Everything works without an account.
Signed in with Solid: alarms are stored on your pod at
```
<your pod origin>/public/alarm/alarms.jsonld
```
The pod origin is taken from your WebID. The document is JSON-LD in the iCal vocabulary: an ical:Vcalendar whose components are ical:Vevents (also typed urn:solid:Alarm), each with an embedded ical:Valarm. Components that are not alarms are kept when the app saves.
Private, despite the /public/ path: when the document is first created, the app also creates alarms.jsonld.acl (only if no ACL exists) granting Read, Write and Control to the owner (/profile/card.jsonld#me) and no public access. All pod requests use xlogin.authFetch.
On first sign-in, alarms in localStorage are copied to the pod only if the pod document is empty. They are not removed from localStorage.
Sync: if the pod advertises an Updates-Via WebSocket, changes made from another device are picked up live.
On sign-out, the app goes back to localStorage.
Ringing and snooze state is not shared between devices: the ringing flag is stripped on save, and snooze time is not written to the pod.

It is a single static index.html with no build step. Serve the folder with any static server, for example:

python3 -m http.server

or npm start (runs npx serve .).

AGPL-3.0-only (from package.json).