From 5b23470f5d9ec7ee7cc33c2b4b936ddd24fa17cc Mon Sep 17 00:00:00 2001
From: Adam Soltys <adam@coinos.io>
Date: Fri, 14 Aug 2026 01:13:47 -0700
Subject: Money leaving while you're not looking gets a notification: NWC pays
 from the worker or a hidden tab announce themselves — amount, fee, and which
 app asked
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Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014tE4U5nEjGTQy8PwYqamfv
---
 src/features/nwc.js | 17 +++++++++++++++++
 src/i18n.js         |  2 ++
 src/nwc-respond.js  | 11 ++++++++++-
 src/sw-nwc.js       |  2 +-
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/features/nwc.js b/src/features/nwc.js
index 686b11f..d6bfdea 100644
--- a/src/features/nwc.js
+++ b/src/features/nwc.js
@@ -212,6 +212,22 @@ export function nwcFeature(ctx) {
     ? nip44.encrypt(txt, nip44.getConversationKey(sk, pk))
     : nip04.encrypt(sk, pk, txt));
 
+  // A pay answered by a hidden tab is as invisible as one paid by the
+  // worker — surface it the same way. A visible tab already shows it live.
+  async function notifySent(c, amountSat, feeSat) {
+    try {
+      if (typeof document === 'undefined' || !document.hidden) return;
+      if (typeof Notification === 'undefined' || Notification.permission !== 'granted') return;
+      const reg = await navigator.serviceWorker.ready;
+      await reg.showNotification(t('nwcPaidTitle'), {
+        body: t('nwcPaidBody', { amount: amountSat.toLocaleString(), name: c.name || 'app' })
+          + (feeSat ? ` (+${feeSat} fee)` : ''),
+        icon: 'icon-192.png', badge: 'icon-192.png',
+        tag: 'nwc-sent', renotify: true, data: { url: './' },
+      });
+    } catch {}
+  }
+
   // Every request gets a reply, including failures — a client that never
   // hears back just hangs.
   async function reply(c, ev, scheme, payload) {
@@ -358,6 +374,7 @@ export function nwcFeature(ctx) {
       const res = await hook('arkPayInvoice', invoice, { maxAmountSat: c.maxSat });
       // the ark seam throws on failure, so reaching here means it settled
       recordSpend(c, (res.amountSat || 0) + (res.feeSat || 0));
+      notifySent(c, res.amountSat || 0, res.feeSat || 0);
       return { result: { preimage: res.preimage, fees_paid: (res.feeSat || 0) * 1000 } };
     }
 
diff --git a/src/i18n.js b/src/i18n.js
index 85f8308..a211eb5 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -663,6 +663,8 @@ const STR = {
     nwcOff: 'Off',
     nwcBackgroundOn: 'Requests will be answered in the background',
     nwcBackgroundOff: 'Background answering turned off',
+    nwcPaidTitle: 'Payment sent',
+    nwcPaidBody: '-{amount} sats via {name}',
     nwcNotifHint: 'You’ll be asked to allow notifications — the connection uses them to answer when Coinos is closed.',
     nwcNotifNeeded: 'Without notifications the connection couldn’t answer when Coinos is closed, so it wasn’t added. Allow notifications and try again.',
     nwcNotifBlocked: 'Notifications are blocked for this site. Allow them in your browser settings, then add the connection again.',
diff --git a/src/nwc-respond.js b/src/nwc-respond.js
index 258b7e7..bd75360 100644
--- a/src/nwc-respond.js
+++ b/src/nwc-respond.js
@@ -280,5 +280,14 @@ export async function respondFromBg(data, {
     result: { preimage: a.preimage, fees_paid: (a.feeSat || 0) * 1000 },
   });
   log(`paid ${a.amountSat || dec.amountSat} sat via the ASP from the background mirror`);
-  return true;
+  // Money left while the app was closed — that always deserves a heads-up,
+  // whether it was a zap from a nostr app or any other connected spender.
+  const paidSat = a.amountSat || dec.amountSat;
+  const feeNote = a.feeSat ? ` (+${a.feeSat} fee)` : '';
+  return {
+    notify: {
+      title: 'Payment sent', tag: 'nwc-sent',
+      body: `-${paidSat.toLocaleString()} sats${feeNote} via ${conn.name || 'a connected app'}`,
+    },
+  };
 }
diff --git a/src/sw-nwc.js b/src/sw-nwc.js
index a73a611..108c393 100644
--- a/src/sw-nwc.js
+++ b/src/sw-nwc.js
@@ -80,7 +80,7 @@ self.addEventListener('push', (e) => {
       await self.registration.showNotification(handled.notify.title, {
         body: handled.notify.body,
         icon: 'icon-192.png', badge: 'icon-192.png',
-        tag: 'nwc-incoming', renotify: true,
+        tag: handled.notify.tag || 'nwc-incoming', renotify: true,
         data: { url: './' },
       });
       return;
-- 
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