wickchart-alerts-plus

The "pro" alert tier for wickchart, as an opt-in plugin — core alerts are runtime-only by design, so persistence, desktop notifications and webhooks live here instead. Zero dependencies.

• Persistence: the chart's alert list is mirrored into localStorage at save points (adds/removes, fires, sync(), detach()) and re-armed on the next page load. Once-fired alerts drop out of storage automatically; alerts added directly on the chart are picked up too.
• Hidden-tab surfacing: while the tab is hidden, a fired alert raises a desktop notification (with the user's permission) and a short two-tone WebAudio beep — no audio files, no dependencies.
• Webhook: an optional URL receives POST { id, price, when, time, bar, key } on every fire, regardless of tab visibility. Fire-and-forget; rejections are swallowed.

npm install wickchart wickchart-alerts-plus   // the plugin is a separate package

import 'wickchart';                              // the chart itself
import { attachAlertsPlus } from 'wickchart-alerts-plus';

const chart = document.querySelector('wick-chart');
const ap = attachAlertsPlus(chart, {
  key: 'BTC:1h',              // storage key — one per symbol+timeframe
  notify: true,               // desktop notification while hidden
  sound: true,                // beep while hidden
  webhook: 'https://example.com/hook', // optional
});
await ap.requestNotify();     // ask for the notification permission once

ap.add({ price: 100, direction: 'above' });   // persisted, re-armed on reload
ap.add({ when: 'rsi(close,14) < 30' });       // scripted alerts persist too
ap.list();                                    // → serializable snapshots
ap.remove(id); ap.clear(); ap.sync(); ap.detach();

Notes:

• storage and fetch are injectable (tests, SSR, custom backends); without storage the plugin is memory-only and never throws — private mode / quota failures are silently best-effort.
• Restored alerts re-arm (fired resets): a non-once alert that fired before a reload can fire again after it.
• Everything on the chart keeps working: addAlert / removeAlert / clearAlerts / getState, wick:alert events, once semantics.

Peer dependency: wickchart ≥ 1.4.0.