A zap answered over NWC waits on far fewer round trips, and a phone with Coinos behind another app answers from its worker. "I'm on V3 … I find nwc zaps a lot more slower than usual" (398ja, 2026-11-10). Measured from the notifier's wakes and the ASP's log over four days: a closed app took about six seconds from the push to its cosign (the Lightning part after that is one and a half), an Android phone fifteen at the median, up to thirty. Where it went: every call to the ASP and the notifier was two round trips (no Access-Control-Max-Age, so Chrome re-asked the CORS preflight after five seconds; a Cloudflare response-header rule now sets 7200 on OPTIONS for ark.coinos.io, ark-staging and nwcpush), and the worker made them one after another: answered?, GetArkInfo, Handshake, claim, a save, the chain tip, then the payment, then status ("pending"), the tip again, the held status call, and status once more for the preimage it had just been handed. Now: what the mirror alone decides (invoice, network, budgets, coins, keys) comes first with no network; the claim (which now also says "already answered", coinosv3-server 3c5e9c3) goes out beside the manager's start, whose info call, handshake and tip run together (init, warmTip/_tipFresh); a send just initiated returns to its caller instead of asking at once, and awaitLnPay settles from the held call's own answer. A worker-style send on regtest: eight calls, six in sequence, where there were thirteen. The app's own answer no longer waits a second on a phone that is on screen (only one behind another app holds back for a computer).

Android freezes an app behind another one, and the worker's nudge to it sat unread until it was opened: on a phone the worker now hands a request only to a window on screen (as it already did on iOS), nudges a hidden one in case it is awake, and answers itself; the request's lock decides between them. For that the mirror is no longer written over the worker's hand: the worker stamps its writes (workerAt), the app writes under the worker's own lock (nwc-bg-work) and folds the worker's state in first (never mid-payment), carries the stamp, absorbs it when it comes back on screen (arkBgAbsorb), and refreshes the mirror as it goes behind another app.
Tests: ln-pay-double-wake (the one held call settles; a failed or mismatched answer doesn't), sw-push-quota (an Android phone's hidden window), nwc-sw-test's notifier stand-in answers /claim as the real one; tools/ark/ln-e2e-test's pay half against regtest captaind 0.8 + CLN

Co-Authored-By: Claude Fable 5.2 <[email protected]>

1 files changed, 26 insertions, 1 deletions

diff --git a/tools/sw-push-quota.test.js b/tools/sw-push-quota.test.js
index 544c72e..798b913 100644
--- a/tools/sw-push-quota.test.js
+++ b/tools/sw-push-quota.test.js
@@ -82,8 +82,33 @@ test('elsewhere: quiet stays quiet', async () => {
   let asked = 0;
   respond = async () => { asked++; return true; };
   expect(await push(nwc)).toEqual([]);
-  expect(asked).toBe(0); // the open (if hidden) window answers on Android
+  expect(asked).toBe(0); // on a computer the open (if hidden) window answers
   windows = [];
   respond = async () => false;
   expect(await push(nwc)).toEqual(['Spend request']);
 });
+
+// An Android phone freezes an app behind another one, minutes in: its relay
+// sockets are dead and the worker's nudge sits unread until it is opened, so
+// a zap sent from another app spun until then (wake to payment: 15 s at the
+// median on Android, 2026-11-10). On a phone only a window on screen is
+// handed the request; behind another app, the worker answers (and nudges the
+// window anyway — the request's lock decides if it is still awake).
+test('an Android phone: the app behind another one does not swallow the request', async () => {
+  endpoint = 'https://fcm.googleapis.com/fcm/send/abc';
+  self.navigator = { userAgent: 'Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/155.0.0.0 Mobile Safari/537.36' };
+  try {
+    let asked = 0, nudged = 0;
+    respond = async () => { asked++; return true; };
+    windows = [{ visibilityState: 'hidden', postMessage: () => { nudged++; } }];
+    expect(await push(nwc)).toEqual([]);
+    expect(asked).toBe(1);
+    expect(nudged).toBe(1);
+    // on screen, it answers itself with everything it knows
+    asked = 0; nudged = 0;
+    windows = [{ visibilityState: 'visible', postMessage: () => { nudged++; } }];
+    expect(await push(nwc)).toEqual([]);
+    expect(asked).toBe(0);
+    expect(nudged).toBe(1);
+  } finally { delete self.navigator; }
+});