A zap answered by two tabs no longer reports as failed.

Every open tab of the same wallet sees every wallet-connect request. Two
hidden tabs on one laptop both tried to pay the same zap: the ASP refused
the second with "payment already in progress", and that error reached
Amethyst half a second before the first tab's preimage. A Web Lock per
request now lets one tab (or the worker) answer while the rest stay
quiet, and a device that does meet "already in progress" waits for the
sibling payment's outcome — relaying its preimage only if the payer never
speaks — instead of shouting a failure over sats that went through. The
losing side also stops writing a failed row into history for it.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QYJfZ4A1TDCEY4Foq3CApR

1 files changed, 4 insertions, 4 deletions

diff --git a/src/sw-nwc.js b/src/sw-nwc.js
index 2566a5c..a166368 100644
--- a/src/sw-nwc.js
+++ b/src/sw-nwc.js
@@ -5,6 +5,7 @@
 // when it can't.
 
 import { respondFromBg } from './nwc-respond.js';
+import { withRequestLock } from './nwc-lock.js';
 import { bgAutoWithdraw } from './bg-autowithdraw.js';
 import { allInboxes, classifyDm, shouldNotifyDm } from './dm-inbox.js';
 
@@ -67,10 +68,9 @@ self.addEventListener('push', (e) => {
     setTimeout(() => { bgAutoWithdraw({ log: (m) => console.log('[sw-aw]', m) }).catch(() => {}); }, 0);
     let handled = false;
     try {
-      handled = await respondFromBg(data, {
-        notifier: NOTIFIER,
-        log: (m) => console.log('[sw-nwc]', m),
-      });
+      handled = await withRequestLock(data.event && data.event.id,
+        () => respondFromBg(data, { notifier: NOTIFIER, log: (m) => console.log('[sw-nwc]', m) }),
+        () => { console.log('[sw-nwc] another context holds this request'); return true; });
     } catch (err) {
       console.warn('[sw-nwc] auto-answer failed:', err && err.message);
     }