The background worker's key window is 250 keys (was 25: PullCap's hourly subscription ran out after 19 payments with the app closed, "key window exhausted"), derived once per account and memoized; 60 receive preimages (was 15). When the worker can't act on a request it still wakes the user, and now leaves a "wait, open the app" error with the notifier that goes out only if nobody answers within 20 s, so the other app hears something instead of silence and a sibling's real payment is never shouted over. A request older than its two-minute window (a push that waited at APNs) is ignored quietly instead of showing "Payment request"

Co-Authored-By: Claude Fable 5.1 <[email protected]>

1 files changed, 10 insertions, 3 deletions

diff --git a/src/nwc-bg.js b/src/nwc-bg.js
index ab083d9..9e7a303 100644
--- a/src/nwc-bg.js
+++ b/src/nwc-bg.js
@@ -133,8 +133,15 @@ export async function allBgs() {
 }
 
 // How many upcoming change/refund indices travel with the record: the worker
-// cannot derive keys, so its allocations must land inside this window.
-export const BG_KEY_LOOKAHEAD = 25;
+// cannot derive keys, so its allocations must land inside this window. Each
+// Lightning send burns a change and an HTLC index, so 25 keys lasted PullCap
+// about 19 hourly payments (2026-10-26, "key window exhausted" after a day
+// with the app closed). 250 keys are 16 KB in the record and cover weeks of
+// hourly payments, or years of monthly ones; the app tops the window up
+// every time it writes the mirror.
+export const BG_KEY_LOOKAHEAD = 250;
+// ...and the receive preimages a closed wallet can mint invoices with
+export const BG_RECV_LOOKAHEAD = 60;
 
 // { ark } endpoints, the manager state to mirror, and a keyFor(chain, index)
 // derive function (the caller owns the account node — it never enters this
@@ -153,7 +160,7 @@ export function buildBg({ ark, mgrState, keyFor, connections, offer, autowithdra
   idx.add(0); // the receive-address key: mailbox/refund defaults land on it
   for (const i of idx) keys[String(i)] = keyFor(3, i);
   const keys5 = {};
-  for (let i = 0; i < 15; i++) {
+  for (let i = 0; i < BG_RECV_LOOKAHEAD; i++) {
     const n = (mgrState.nextLnRecvIndex || 0) + i;
     keys5[String(n)] = keyFor(5, n);
   }