From 7af3c430d49d7817e9a0cf28ab49143edba4c00f Mon Sep 17 00:00:00 2001
From: Adam Soltys <adam@coinos.io>
Date: Wed, 24 Jun 2026 23:23:50 -0700
Subject: Make pending receives fast: cut REST load, surface live/polling state
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Incoming deposits show instantly when the mempool.space WebSocket is healthy
(_ingestWs updates immediately). The lag came from the socket being starved:
a 20s frontier poll plus a full wallet re-scan every 120s generated enough
REST volume to trip mempool's per-IP rate limit (the 429/CORS errors), which
in turn degraded the socket — a feedback loop.

- While the socket is live, skip the periodic full scan entirely (the WS pushes
  confirmations and block events) and poll the frontier only every ~25s as a
  half-open-socket safety net — near-zero recurring REST.
- While the socket is down, poll the frontier every ~6s (was 20s) so receives
  still show quickly, and keep the 120s reconcile scan.
- Refresh the frontier on WS (re)connect to catch deposits that landed while
  disconnected.
- Surface a Live/Polling badge on the balance card so a stuck socket is visible.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/wallet.js | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

(limited to 'src/wallet.js')

diff --git a/src/wallet.js b/src/wallet.js
index af827f3..f52efdf 100644
--- a/src/wallet.js
+++ b/src/wallet.js
@@ -92,6 +92,7 @@ export class Wallet {
     this._pollTimer = null;
     this._deepTimer = null; // periodic full-scan safety net
     this._polling = false; // a light poll is in flight
+    this._lastPoll = 0; // last frontier poll (throttles the adaptive poll timer)
     this._hbTimer = null; // heartbeat / liveness watchdog
     this._lastMsg = 0; // time of last WS message (incl. pong)
     this._wakeHooked = false;
@@ -1066,13 +1067,26 @@ export class Wallet {
   startRealtime() {
     if (this.offline) return;
     this.stopRealtime();
-    // Safety-net poll: only the fresh frontier (next receive/change address),
-    // in case the WebSocket misses a deposit. Already-scanned addresses are
-    // never re-polled — the deep scan below covers spends/confirmations.
-    this._pollTimer = setInterval(() => this.refreshLive(), 20000);
-    // Periodic full scan: reconciles everything refreshLive can't see on its own
-    // — pending→confirmed history, spends, and stale cache/relay state.
-    this._deepTimer = setInterval(() => this.scan({ silent: true }).catch(() => {}), 120000);
+    // Frontier poll (next receive/change address only). While the socket is live
+    // it pushes deposits instantly, so we poll just as a slow half-open-socket
+    // safety net (~25s). When the socket is down, poll fast (~6s) so receives
+    // still show quickly. The 3s tick is a cheap time check — it issues no
+    // request unless one is due, which keeps REST volume (and 429s) low.
+    this._pollTimer = setInterval(() => {
+      if (this.offline) return;
+      const due = this.live ? 25000 : 6000;
+      if (Date.now() - (this._lastPoll || 0) < due) return;
+      this._lastPoll = Date.now();
+      this.refreshLive();
+    }, 3000);
+    // Periodic full scan: reconciles pending→confirmed history, spends, and
+    // stale cache/relay state — but only when the socket is down. While live the
+    // WS already pushes confirmations and block events, so a full re-scan would
+    // just burn the rate limit (and risk starving the very socket we rely on).
+    this._deepTimer = setInterval(() => {
+      if (this.live) return;
+      this.scan({ silent: true }).catch(() => {});
+    }, 120000);
     // Only mempool.space has a live socket; other explorers rely on the poll
     // and deep scan above (wsUrl returns null → no socket).
     if (typeof WebSocket === 'undefined' || !this.wsUrl()) return;
@@ -1136,6 +1150,9 @@ export class Wallet {
       this._lastMsg = Date.now();
       this.retrack();
       this.emit();
+      // Catch any deposit that landed while we were disconnected — mempool only
+      // pushes new activity after tracking starts, not what's already there.
+      this.refreshLive().catch(() => {});
     };
     ws.onmessage = (ev) => {
       this._lastMsg = Date.now();
-- 
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