Fold the coinos opt-out into a single Data source picker

Replace the Esplora|Electrum backend toggle plus the separate 'Instant
notifications' on/off with one 'Data source' selector:
  • coinos (instant)  — default; explorer data + coinos push
  • Block explorer     — REST + polling, nothing sent to coinos (the opt-out)
  • Electrum server    — one WS server for data + push (your node / public)

Picking a non-coinos source IS the privacy opt-out, so the standalone toggle is
gone. A single 'mode' setting drives getBackend()/getRealtimeEnabled(), so the
wallet/wsUrl logic is unchanged; existing per-feature settings migrate in
(realtime=off → explorer, backend=electrum → electrum). coinos⇄explorer just
flips the watcher (no rescan); to/from electrum rebuilds the backend.

Sets up cleanly for a future coinos Fulcrum: 'coinos' mode upgrades from
REST+watcher to a full Electrum backend transparently.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

3 files changed, 57 insertions, 58 deletions

diff --git a/src/api.js b/src/api.js
index 4d4212f..03db6b9 100644
--- a/src/api.js
+++ b/src/api.js
@@ -60,26 +60,31 @@ export function getElectrumWsUrl() {
   return 'wss://coinos.io/electrum';
 }
 
-// Privacy opt-out: turning this off means the app never connects to coinos's
-// watcher (so it can't see your addresses) and relies on polling your explorer
-// instead. On by default.
-const REALTIME_KEY = 'btc-wallet-realtime';
-export function getRealtimeEnabled() {
-  try { return localStorage.getItem(REALTIME_KEY) !== 'off'; } catch { return true; }
-}
-export function setRealtimeEnabled(on) {
-  try { localStorage.setItem(REALTIME_KEY, on ? 'on' : 'off'); } catch {}
-}
-
-// Data backend: the default Esplora REST (`Api`) or a full Electrum-over-WS
-// server (`ElectrumApi`) that serves data AND notifications over one connection.
-const BACKEND_KEY = 'btc-wallet-backend';
-export function getBackend() {
-  try { return localStorage.getItem(BACKEND_KEY) === 'electrum' ? 'electrum' : 'esplora'; } catch { return 'esplora'; }
+// One "data source" setting drives both where chain data comes from and whether
+// coinos sees your addresses for instant push:
+//   coinos   — block-explorer data + coinos instant-payment notifications (default)
+//   explorer — block-explorer data only; polls for payments, nothing sent to coinos
+//   electrum — a single Electrum-over-WS server for both data and push (your node)
+// getBackend()/getRealtimeEnabled() derive from it, so the rest of the code (and
+// the wsUrl logic) is unchanged. Existing per-feature settings migrate in.
+const DATA_MODE_KEY = 'btc-wallet-mode';
+const BACKEND_KEY = 'btc-wallet-backend'; // legacy (migration only)
+const REALTIME_KEY = 'btc-wallet-realtime'; // legacy (migration only)
+export function getDataMode() {
+  try {
+    const m = localStorage.getItem(DATA_MODE_KEY);
+    if (m === 'coinos' || m === 'explorer' || m === 'electrum') return m;
+    if (localStorage.getItem(BACKEND_KEY) === 'electrum') return 'electrum';
+    if (localStorage.getItem(REALTIME_KEY) === 'off') return 'explorer';
+  } catch {}
+  return 'coinos';
 }
-export function setBackend(b) {
-  try { localStorage.setItem(BACKEND_KEY, b === 'electrum' ? 'electrum' : 'esplora'); } catch {}
+export function setDataMode(m) {
+  try { localStorage.setItem(DATA_MODE_KEY, m === 'electrum' || m === 'explorer' ? m : 'coinos'); } catch {}
 }
+export function getBackend() { return getDataMode() === 'electrum' ? 'electrum' : 'esplora'; }
+// The coinos watcher is used only in 'coinos' mode; 'explorer' polls instead.
+export function getRealtimeEnabled() { return getDataMode() === 'coinos'; }
 
 // Electrum servers that accept WebSocket connections. blockstream.info is
 // electrs (validated); the point, though, is pointing at your own Fulcrum/electrs.
diff --git a/src/app.js b/src/app.js
index 6a994d8..8524528 100644
--- a/src/app.js
+++ b/src/app.js
@@ -8,7 +8,7 @@ import { Wallet, newMnemonic, isValidMnemonic, utxoId, previewGift, giftOutpoint
 import { qrSvg } from './qr.js';
 import { scanQr } from './scan.js';
 import { getSyncConfig, setSyncConfig } from './nostr.js';
-import { getExplorerConfig, setExplorerConfig, EXPLORER_PRESETS, getRealtimeEnabled, setRealtimeEnabled, getBackend, setBackend, ELECTRUM_PRESETS, getElectrumServerConfig, setElectrumServerConfig } from './api.js';
+import { getExplorerConfig, setExplorerConfig, EXPLORER_PRESETS, getDataMode, setDataMode, ELECTRUM_PRESETS, getElectrumServerConfig, setElectrumServerConfig } from './api.js';
 import { isSilentPaymentAddress } from './silentpay.js';
 import { t, LANGS, getLang, setLang, isRTL, loadLocale } from './i18n.js';
 import {
@@ -1298,36 +1298,34 @@ async function doRevoke(id) {
 // Block explorer / server selection: a preset (mempool.space, blockstream.info)
 // or a custom Esplora/electrs REST URL (e.g. your own node).
 function explorerCard() {
-  const backend = getBackend();
+  const mode = getDataMode();
   const cfg = getExplorerConfig();
   const ecfg = getElectrumServerConfig();
-  const rt = getRealtimeEnabled();
-  const setRealtime = (on) => {
-    if (on === getRealtimeEnabled()) return;
-    setRealtimeEnabled(on);
+  const setMode = (m) => {
+    const prev = getDataMode();
+    if (m === prev) return;
+    setDataMode(m);
     render();
-    if (!wallet.offline) wallet.startRealtime(); // reconnect or drop the watcher
-  };
-  const setBackendTo = (b) => {
-    if (b === getBackend()) return;
-    setBackend(b);
-    render();
-    if (!wallet.offline) wallet.reloadExplorer(); // rebuild api + reconnect
+    if (wallet.offline) return;
+    // coinos⇄explorer only flips the watcher (same REST data); to/from electrum
+    // swaps the whole backend, so rebuild + rescan there.
+    if ((m === 'electrum') !== (prev === 'electrum')) wallet.reloadExplorer();
+    else wallet.startRealtime();
   };
   return h(
     'div',
     { class: 'card col' },
-    h('h3', {}, t('explorer')),
-    h('p', { class: 'small muted', style: 'margin:0' }, t('explorerDesc')),
-    // Data source: Esplora REST, or a full Electrum-over-WS server (data + push).
-    h('div', { class: 'row between', style: 'margin-top:2px' },
-      h('span', { class: 'lab', style: 'margin:0' }, t('dataSource')),
-      h('div', { class: 'seg' },
-        h('button', { type: 'button', class: backend === 'esplora' ? 'active' : '', onClick: () => setBackendTo('esplora') }, t('backendEsplora')),
-        h('button', { type: 'button', class: backend === 'electrum' ? 'active' : '', onClick: () => setBackendTo('electrum') }, t('backendElectrum'))
-      )
+    h('h3', {}, t('dataSource')),
+    h('p', { class: 'small muted', style: 'margin:0' }, t('dataSourceDesc')),
+    h('select', { onChange: (e) => setMode(e.target.value) },
+      h('option', { value: 'coinos', selected: mode === 'coinos' }, t('modeCoinos')),
+      h('option', { value: 'explorer', selected: mode === 'explorer' }, t('modeExplorer')),
+      h('option', { value: 'electrum', selected: mode === 'electrum' }, t('modeElectrum'))
     ),
-    backend === 'electrum'
+    mode === 'coinos'
+      ? h('div', { class: 'small faint' }, t('modeCoinosDesc'))
+      : null,
+    mode === 'electrum'
       ? h('div', { class: 'col', style: 'gap:8px' },
           h('div', { class: 'small faint' }, t('backendElectrumDesc')),
           h('select', {
@@ -1345,7 +1343,10 @@ function explorerCard() {
               )
             : null
         )
-      : h('div', { class: 'col', style: 'gap:8px' },
+      : null,
+    mode === 'explorer'
+      ? h('div', { class: 'col', style: 'gap:8px' },
+          h('div', { class: 'small faint' }, t('modeExplorerDesc')),
           h('select', {
             onChange: (e) => { setExplorerConfig({ server: e.target.value, url: cfg.url }); render(); if (e.target.value !== 'custom' || cfg.url) wallet.reloadExplorer(); },
           }, EXPLORER_PRESETS.map((o) => h('option', { value: o.id, selected: o.id === cfg.server }, o.label))),
@@ -1359,18 +1360,9 @@ function explorerCard() {
                 }),
                 h('div', { class: 'small faint' }, t('explorerUrlHint'))
               )
-            : null,
-          // Realtime via coinos — the one place addresses are shared off-device.
-          // (Electrum already serves its own push, so this only applies to REST.)
-          h('div', { class: 'row between', style: 'margin-top:8px' },
-            h('span', { class: 'lab', style: 'margin:0' }, t('instantNotif')),
-            h('div', { class: 'seg' },
-              h('button', { type: 'button', class: rt ? 'active' : '', onClick: () => setRealtime(true) }, t('syncOn')),
-              h('button', { type: 'button', class: !rt ? 'active' : '', onClick: () => setRealtime(false) }, t('syncOff'))
-            )
-          ),
-          h('div', { class: 'small faint' }, t('instantNotifDesc'))
+            : null
         )
+      : null
   );
 }
 
diff --git a/src/i18n.js b/src/i18n.js
index aa8b499..e3341a7 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -260,14 +260,16 @@ const STR = {
     explorerUrl: 'Server URL',
     explorerUrlHint: 'Esplora / electrs REST base, e.g. https://mempool.space/api',
     dataSource: 'Data source',
-    backendEsplora: 'Explorer',
-    backendElectrum: 'Electrum',
-    backendElectrumDesc: 'Fetch data and get instant payments over one Electrum WebSocket. Point it at your own Fulcrum/electrs for a fully self-hosted wallet — no coinos, no REST.',
+    dataSourceDesc: 'Where Hal reads the chain and how it learns about incoming payments.',
+    modeCoinos: 'coinos (instant)',
+    modeCoinosDesc: 'The default. Instant payment alerts via coinos, with chain data from a public block explorer.',
+    modeExplorer: 'Block explorer',
+    modeExplorerDesc: 'Reads from your chosen block explorer and polls for payments — nothing is sent to coinos. A bit slower.',
+    modeElectrum: 'Electrum server',
+    backendElectrumDesc: 'Data and instant payments over one Electrum WebSocket. Point it at your own Fulcrum/electrs for a fully self-hosted wallet — no coinos, no REST.',
     electrumUrl: 'Electrum server (wss://)',
     electrumUrlHint: 'A WebSocket Electrum server, e.g. wss://your-node:50004',
     silentPaymentNote: 'Silent payment',
-    instantNotif: 'Instant notifications',
-    instantNotifDesc: 'Uses coinos to push payments the instant they arrive. Turn off to poll the explorer above instead — a bit slower, but your addresses are never sent to coinos.',
     deviceSync: 'Device sync',
     deviceSyncDesc: 'Keep this wallet in sync across your devices by storing an encrypted copy on a Nostr relay — only a device with your seed can read it. Turn it off to keep everything on this device.',
     syncAcross: 'Sync across devices',