feat: replace view-key monitor with TX proof verification

Remove v2 view-key payment monitor (privacy concern — nobody should enter their private view key on a website). Replace with TX proof verification where the sender provides TX Hash + TX Key from their wallet. The proof is cryptographically verified client-side and stored with the invoice for persistent "Paid" status. - Remove monitor.js and all view-key monitoring UI/logic - Add TX proof section: sender enters TX Hash + TX Key - Client-side verification via check_tx_key equivalent (noble-curves) - api/verify.php stores/retrieves payment proofs per invoice - Short URL redirect now includes invoice code for status lookup - Invoice link shows "Paid" badge once proof is verified - Deadline badges (7/14/30 days) for payment terms
2026-03-25 09:37:09 +01:00
parent 1acf990943
commit 32245fccdf
9 changed files with 318 additions and 696 deletions
--- a/README.md
+++ b/README.md
@@ -67,15 +67,14 @@ Die App ist eine einzige HTML-Datei, die von überall gehostet werden kann.
 - [x] Offline-fähig via Service Worker
 - [x] CoinGecko-Fallback mit Auto-Retry

-### v2 — View-Key Zahlungsbestätigung (Browser-basiert) ✅
+### v2 — TX Proof Zahlungsbestätigung ✅

- [x] Private View-Key eingeben (validiert gegen Adresse, verlässt nie den Browser)
- [x] Browser pollt Remote Node via PHP-Proxy mit Failover (4 Nodes)
- [x] Live-Anzeige: "Warte auf Zahlung..." → "Zahlung eingegangen (X/10 Bestätigungen)"
- [x] Fortschrittsbalken für Bestätigungen
- [x] Unterzahlungs-Erkennung
+- [x] Sender gibt TX Hash + TX Key ein (aus Wallet kopiert)
+- [x] Kryptografische Verifizierung im Browser (30KB noble-curves Bundle)
+- [x] Zahlungsstatus wird dauerhaft mit Rechnung gespeichert
+- [x] Rechnungs-Link zeigt "Bezahlt" Badge nach Verifizierung
 - [x] Standard- und Subaddress-Unterstützung
- [x] Leichtgewichtige Krypto (30KB noble-curves Bundle, kein 5MB WASM)
+- [x] Kein Private View Key nötig — kein Privacy-Risiko

 ### v3 — Professionelle Features

--- a/api/verify.php
+++ b/api/verify.php
@@ -0,0 +1,86 @@
+<?php
+/**
+ * TX Proof Storage API
+ * POST: Store verified payment proof for an invoice
+ * GET:  Retrieve payment status for an invoice
+ */
+
+header('Content-Type: application/json');
+
+$dbFile = __DIR__ . '/../data/proofs.json';
+$proofs = [];
+if (file_exists($dbFile)) {
+    $proofs = json_decode(file_get_contents($dbFile), true) ?: [];
+}
+
+// GET: Retrieve proof
+if ($_SERVER['REQUEST_METHOD'] === 'GET') {
+    $code = $_GET['code'] ?? '';
+    if (empty($code) || !preg_match('/^[a-z0-9]{4,10}$/', $code)) {
+        echo json_encode(['verified' => false]);
+        exit;
+    }
+
+    if (isset($proofs[$code])) {
+        echo json_encode(array_merge(['verified' => true], $proofs[$code]));
+    } else {
+        echo json_encode(['verified' => false]);
+    }
+    exit;
+}
+
+// POST: Store proof
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    http_response_code(405);
+    echo json_encode(['error' => 'Method not allowed']);
+    exit;
+}
+
+$input = json_decode(file_get_contents('php://input'), true);
+if (!$input) {
+    http_response_code(400);
+    echo json_encode(['error' => 'Invalid JSON']);
+    exit;
+}
+
+$code = $input['code'] ?? '';
+$txHash = $input['tx_hash'] ?? '';
+$amount = floatval($input['amount'] ?? 0);
+$confirmations = intval($input['confirmations'] ?? 0);
+
+// Validate
+if (!preg_match('/^[a-z0-9]{4,10}$/', $code)) {
+    http_response_code(400);
+    echo json_encode(['error' => 'Invalid code']);
+    exit;
+}
+if (!preg_match('/^[0-9a-fA-F]{64}$/', $txHash)) {
+    http_response_code(400);
+    echo json_encode(['error' => 'Invalid tx_hash']);
+    exit;
+}
+
+// Verify the short URL code exists
+$urlsFile = __DIR__ . '/../data/urls.json';
+if (!file_exists($urlsFile)) {
+    http_response_code(404);
+    echo json_encode(['error' => 'Invoice not found']);
+    exit;
+}
+$urls = json_decode(file_get_contents($urlsFile), true) ?: [];
+if (!isset($urls[$code])) {
+    http_response_code(404);
+    echo json_encode(['error' => 'Invoice not found']);
+    exit;
+}
+
+// Store proof
+$proofs[$code] = [
+    'tx_hash' => strtolower($txHash),
+    'amount' => $amount,
+    'confirmations' => $confirmations,
+    'verified_at' => time()
+];
+
+file_put_contents($dbFile, json_encode($proofs, JSON_PRETTY_PRINT));
+echo json_encode(['ok' => true]);
--- a/app.js
+++ b/app.js
@@ -38,19 +38,14 @@
  const newRequestBtn = $('#newRequest');
  const homeLink = $('#homeLink');

-  // Monitor DOM
-  const monitorSection = $('#monitorSection');
-  const monitorToggle = $('#monitorToggle');
-  const monitorPanel = $('#monitorPanel');
-  const viewKeyInput = $('#viewKey');
-  const startMonitorBtn = $('#startMonitor');
-  const stopMonitorBtn = $('#stopMonitor');
-  const monitorStatus = $('#monitorStatus');
-  const statusIndicator = $('#statusIndicator');
-  const statusText = $('#statusText');
-  const confirmationsBar = $('#confirmationsBar');
-  const confirmationsFill = $('#confirmationsFill');
-  const confirmationsText = $('#confirmationsText');
+  // TX Proof DOM
+  const proofToggle = $('#proofToggle');
+  const proofPanel = $('#proofPanel');
+  const txHashInput = $('#txHash');
+  const txKeyInput = $('#txKey');
+  const verifyProofBtn = $('#verifyProof');
+  const proofResult = $('#proofResult');
+  const paymentStatus = $('#paymentStatus');
  let cryptoLoaded = false;

  // --- Init ---
@@ -90,11 +85,11 @@
    selectedDays = parseInt(timerCustom.value) || 0;
  });

-  // Monitor events
-  monitorToggle.addEventListener('click', toggleMonitor);
-  viewKeyInput.addEventListener('input', validateViewKey);
-  startMonitorBtn.addEventListener('click', startMonitoring);
-  stopMonitorBtn.addEventListener('click', stopMonitoring);
+  // TX Proof events
+  proofToggle.addEventListener('click', toggleProofPanel);
+  txHashInput.addEventListener('input', validateProofInputs);
+  txKeyInput.addEventListener('input', validateProofInputs);
+  verifyProofBtn.addEventListener('click', verifyTxProof);

  // --- Functions ---

@@ -115,12 +110,15 @@
    qrContainer.innerHTML = '';
    uriBox.textContent = '';
    shareLinkInput.value = '';
-    // Reset monitor
-    stopMonitoring();
-    monitorPanel.classList.remove('open');
-    viewKeyInput.value = '';
-    viewKeyInput.classList.remove('valid', 'invalid');
-    startMonitorBtn.disabled = true;
+    // Reset proof
+    proofPanel.classList.remove('open');
+    txHashInput.value = '';
+    txKeyInput.value = '';
+    verifyProofBtn.disabled = true;
+    proofResult.innerHTML = '';
+    proofResult.className = 'proof-result';
+    paymentStatus.innerHTML = '';
+    paymentStatus.className = 'payment-status';
    history.replaceState(null, '', location.pathname);
    window.scrollTo({ top: 0, behavior: 'smooth' });
    addrInput.focus();
@@ -308,6 +306,12 @@
      }
    }

+    // Check for short URL code and load payment status
+    const code = params.get('c');
+    if (code) {
+      setTimeout(function () { loadPaymentStatus(code); }, 200);
+    }
+
    // Auto-generate
    setTimeout(generate, 100);
    return true;
@@ -413,134 +417,160 @@
    }
  }

-  // --- Monitor Functions (v2) ---
+  // --- TX Proof Functions ---

-  function toggleMonitor() {
-    const panel = monitorPanel;
-    const isOpen = panel.classList.contains('open');
+  function toggleProofPanel() {
+    const isOpen = proofPanel.classList.contains('open');
    if (isOpen) {
-      panel.classList.remove('open');
+      proofPanel.classList.remove('open');
      return;
    }
    // Lazy-load crypto bundle
    if (!cryptoLoaded && !window.XmrCrypto) {
      loadCryptoBundle().then(function () {
        cryptoLoaded = true;
-        panel.classList.add('open');
-        viewKeyInput.focus();
+        proofPanel.classList.add('open');
+        txHashInput.focus();
      });
      return;
    }
-    panel.classList.add('open');
-    viewKeyInput.focus();
+    proofPanel.classList.add('open');
+    txHashInput.focus();
  }

  function loadCryptoBundle() {
    return new Promise(function (resolve, reject) {
      if (window.XmrCrypto) { resolve(); return; }
-      statusText.textContent = I18n.t('monitor_loading');
-      monitorStatus.classList.add('active');
      const script = document.createElement('script');
      script.src = 'lib/xmr-crypto.bundle.js';
-      script.onload = function () {
-        monitorStatus.classList.remove('active');
-        resolve();
-      };
-      script.onerror = function () {
-        monitorStatus.classList.remove('active');
-        reject(new Error('Failed to load crypto module'));
-      };
+      script.onload = resolve;
+      script.onerror = function () { reject(new Error('Failed to load crypto module')); };
      document.head.appendChild(script);
    });
  }

-  function validateViewKey() {
-    const key = viewKeyInput.value.trim();
-    viewKeyInput.classList.remove('valid', 'invalid');
-    if (key.length === 0) {
-      startMonitorBtn.disabled = true;
+  function isValidHex64(val) {
+    return /^[0-9a-fA-F]{64}$/.test(val);
+  }
+
+  function validateProofInputs() {
+    const hash = txHashInput.value.trim();
+    const key = txKeyInput.value.trim();
+    verifyProofBtn.disabled = !(isValidHex64(hash) && isValidHex64(key));
+  }
+
+  async function verifyTxProof() {
+    const txHash = txHashInput.value.trim();
+    const txKey = txKeyInput.value.trim();
+    const addr = addrInput.value.trim();
+    if (!isValidHex64(txHash) || !isValidHex64(txKey) || !isValidAddress(addr)) return;
+
+    verifyProofBtn.disabled = true;
+    proofResult.className = 'proof-result active';
+    proofResult.textContent = I18n.t('proof_verifying');
+
+    try {
+      // Fetch TX from node
+      var res = await fetch('/api/node.php', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ method: 'gettransactions', params: { txs_hashes: [txHash], decode_as_json: true } })
+      });
+      var data = await res.json();
+      var txs = data.txs || [];
+      if (txs.length === 0) {
+        proofResult.className = 'proof-result active error';
+        proofResult.textContent = I18n.t('proof_tx_not_found');
+        verifyProofBtn.disabled = false;
        return;
      }
-    if (PaymentMonitor.isValidViewKey(key)) {
-      viewKeyInput.classList.add('valid');
-      startMonitorBtn.disabled = false;
-    } else if (key.length >= 10) {
-      viewKeyInput.classList.add('invalid');
-      startMonitorBtn.disabled = true;
+
+      var tx = txs[0];
+      var txJson = JSON.parse(tx.as_json);
+
+      // Get keys from address
+      var keys = XmrCrypto.getKeysFromAddress(addr);
+      var pubViewKey = keys.publicViewKey;
+      var pubSpendKey = keys.publicSpendKey;
+
+      // Key derivation: D = 8 * txKey * pubViewKey
+      var r = XmrCrypto.bytesToScalar(XmrCrypto.hexToBytes(txKey));
+      var A = XmrCrypto.Point.fromHex(pubViewKey);
+      var D = A.multiply(r).multiply(8n);
+      var derivation = D.toBytes();
+
+      var B = XmrCrypto.Point.fromHex(pubSpendKey);
+
+      // Check each output
+      var outputs = txJson.vout || [];
+      var ecdhInfo = (txJson.rct_signatures && txJson.rct_signatures.ecdhInfo) || [];
+      var totalAmount = 0n;
+      var found = false;
+
+      for (var oi = 0; oi < outputs.length; oi++) {
+        var out = outputs[oi];
+        var outputKey = out.target && out.target.tagged_key ? out.target.tagged_key.key : (out.target && out.target.key);
+        if (!outputKey) continue;
+
+        var varint = XmrCrypto.encodeVarint(oi);
+        var scalar = XmrCrypto.hashToScalar(XmrCrypto.concat(derivation, varint));
+        var scBig = XmrCrypto.bytesToScalar(scalar);
+        var expectedP = XmrCrypto.Point.BASE.multiply(scBig).add(B);
+        var expectedHex = XmrCrypto.bytesToHex(expectedP.toBytes());
+
+        if (expectedHex === outputKey) {
+          found = true;
+          // Decode amount
+          if (ecdhInfo[oi] && ecdhInfo[oi].amount) {
+            var amount = XmrCrypto.decodeRctAmount(ecdhInfo[oi].amount, derivation, oi);
+            totalAmount += amount;
+          }
        }
      }

-  function startMonitoring() {
-    const viewKey = viewKeyInput.value.trim();
-    if (!PaymentMonitor.isValidViewKey(viewKey)) return;
+      if (found) {
+        var xmrAmount = Number(totalAmount) / 1e12;
+        proofResult.className = 'proof-result active success';
+        proofResult.textContent = I18n.t('proof_verified').replace('{amount}', xmrAmount.toFixed(6));

-    const addr = addrInput.value.trim();
-    const xmrAmount = getXmrAmount() || 0;
-
-    // Hide input, show status
-    startMonitorBtn.style.display = 'none';
-    viewKeyInput.closest('.field').style.display = 'none';
-    monitorStatus.classList.add('active');
-    stopMonitorBtn.classList.add('active');
-
-    PaymentMonitor.start(addr, viewKey, xmrAmount, function (newState, data) {
-      updateMonitorUI(newState, data);
+        // Store proof with invoice
+        var shareUrl = shareLinkInput.value;
+        var codeMatch = shareUrl.match(/\/s\/([a-z0-9]+)/);
+        if (codeMatch) {
+          await fetch('/api/verify.php', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({
+              code: codeMatch[1],
+              tx_hash: txHash,
+              amount: xmrAmount,
+              confirmations: tx.confirmations || 0
+            })
          });
        }
-
-  function stopMonitoring() {
-    PaymentMonitor.stop();
-    monitorStatus.classList.remove('active');
-    confirmationsBar.classList.remove('active');
-    stopMonitorBtn.classList.remove('active');
-    startMonitorBtn.style.display = '';
-    viewKeyInput.closest('.field').style.display = '';
-    statusIndicator.className = 'status-indicator';
-    statusText.textContent = '';
+      } else {
+        proofResult.className = 'proof-result active error';
+        proofResult.textContent = I18n.t('proof_no_match');
+      }
+    } catch (e) {
+      proofResult.className = 'proof-result active error';
+      proofResult.textContent = I18n.t('proof_error');
+    }
+    verifyProofBtn.disabled = false;
  }

-  function updateMonitorUI(monitorState, data) {
-    const S = PaymentMonitor.STATE;
-    statusIndicator.className = 'status-indicator ' + monitorState;
-
-    switch (monitorState) {
-      case S.CONNECTING:
-        statusText.textContent = I18n.t('monitor_connecting');
-        confirmationsBar.classList.remove('active');
-        break;
-      case S.SCANNING:
-        statusText.textContent = I18n.t('monitor_scanning');
-        break;
-      case S.WAITING:
-        statusText.textContent = I18n.t('monitor_waiting');
-        break;
-      case S.MEMPOOL:
-        statusText.textContent = I18n.t('monitor_mempool');
-        showConfirmations(data.confirmations);
-        break;
-      case S.CONFIRMED:
-        statusText.textContent = I18n.t('monitor_confirmed');
-        showConfirmations(data.confirmations);
-        stopMonitorBtn.classList.remove('active');
-        break;
-      case S.UNDERPAID:
-        statusText.textContent = I18n.t('monitor_underpaid');
-        var detail = I18n.t('monitor_underpaid_detail')
-          .replace('{expected}', data.expected.toFixed(6))
-          .replace('{received}', data.received.toFixed(6));
-        statusText.textContent += '\n' + detail;
-        showConfirmations(data.confirmations);
-        break;
-      case S.ERROR:
-        statusText.textContent = data.message || I18n.t('monitor_node_error');
-        break;
+  // Load payment status if viewing via short URL
+  function loadPaymentStatus(code) {
+    fetch('/api/verify.php?code=' + encodeURIComponent(code))
+      .then(function (res) { return res.json(); })
+      .then(function (data) {
+        if (data.verified) {
+          paymentStatus.className = 'payment-status paid';
+          paymentStatus.innerHTML = '<div class="paid-badge">' + I18n.t('status_paid') +
+            '</div><div class="paid-detail">' + data.amount.toFixed(6) + ' XMR — TX ' +
+            data.tx_hash.substring(0, 8) + '...</div>';
        }
-  }
-
-  function showConfirmations(n) {
-    confirmationsBar.classList.add('active');
-    var pct = Math.min(100, (n / 10) * 100);
-    confirmationsFill.style.width = pct + '%';
-    confirmationsText.textContent = I18n.t('monitor_confirmations').replace('{n}', n);
+      })
+      .catch(function () {});
  }
 })();
--- a/i18n.js
+++ b/i18n.js
@@ -29,22 +29,18 @@ var I18n = (function () {
      countdown_remaining_days: 'Zahlungsfrist: {d} Tage, {h}:{m}:{s}',
      countdown_remaining_hours: 'Zahlungsfrist: {h}:{m}:{s}',
      rates_offline: 'Kurse nicht verfügbar — nur XMR-Betrag möglich',
-      btn_monitor: 'Zahlung überwachen',
-      label_view_key: 'Privater View-Key',
-      placeholder_view_key: '64 Hex-Zeichen...',
-      hint_view_key: 'Der View-Key verlässt nie deinen Browser',
-      btn_start_monitor: 'Überwachung starten',
-      btn_stop_monitor: 'Überwachung beenden',
-      monitor_connecting: 'Verbinde mit Node...',
-      monitor_scanning: 'Scanne Mempool...',
-      monitor_waiting: 'Warte auf Zahlung...',
-      monitor_mempool: 'Zahlung erkannt (unbestätigt)',
-      monitor_confirmed: 'Zahlung bestätigt',
-      monitor_confirmations: '{n}/10 Bestätigungen',
-      monitor_underpaid: 'Unterzahlung erkannt',
-      monitor_underpaid_detail: 'Erwartet: {expected} XMR — Erhalten: {received} XMR',
-      monitor_node_error: 'Node nicht erreichbar — versuche nächsten...',
-      monitor_loading: 'Lade Kryptografie-Modul...'
+      btn_prove_payment: 'Zahlung nachweisen',
+      label_tx_hash: 'Transaction ID (TX Hash)',
+      placeholder_tx_hash: '64 Hex-Zeichen...',
+      label_tx_key: 'Transaction Key (TX Key)',
+      placeholder_tx_key: '64 Hex-Zeichen...',
+      btn_verify_proof: 'Zahlung verifizieren',
+      proof_verifying: 'Verifiziere...',
+      proof_verified: 'Zahlung bestätigt: {amount} XMR',
+      proof_no_match: 'Kein passender Output gefunden — TX Key oder Adresse stimmt nicht',
+      proof_tx_not_found: 'Transaktion nicht gefunden',
+      proof_error: 'Fehler bei der Verifizierung',
+      status_paid: 'Bezahlt'
    },
    en: {
      subtitle: 'Monero payment request in seconds',
@@ -68,22 +64,18 @@ var I18n = (function () {
      countdown_remaining_days: 'Deadline: {d} days, {h}:{m}:{s}',
      countdown_remaining_hours: 'Deadline: {h}:{m}:{s}',
      rates_offline: 'Rates unavailable — XMR amount only',
-      btn_monitor: 'Monitor payment',
-      label_view_key: 'Private view key',
-      placeholder_view_key: '64 hex characters...',
-      hint_view_key: 'Your view key never leaves your browser',
-      btn_start_monitor: 'Start monitoring',
-      btn_stop_monitor: 'Stop monitoring',
-      monitor_connecting: 'Connecting to node...',
-      monitor_scanning: 'Scanning mempool...',
-      monitor_waiting: 'Waiting for payment...',
-      monitor_mempool: 'Payment detected (unconfirmed)',
-      monitor_confirmed: 'Payment confirmed',
-      monitor_confirmations: '{n}/10 confirmations',
-      monitor_underpaid: 'Underpayment detected',
-      monitor_underpaid_detail: 'Expected: {expected} XMR — Received: {received} XMR',
-      monitor_node_error: 'Node unreachable — trying next...',
-      monitor_loading: 'Loading crypto module...'
+      btn_prove_payment: 'Prove payment',
+      label_tx_hash: 'Transaction ID (TX Hash)',
+      placeholder_tx_hash: '64 hex characters...',
+      label_tx_key: 'Transaction Key (TX Key)',
+      placeholder_tx_key: '64 hex characters...',
+      btn_verify_proof: 'Verify payment',
+      proof_verifying: 'Verifying...',
+      proof_verified: 'Payment confirmed: {amount} XMR',
+      proof_no_match: 'No matching output found — TX key or address mismatch',
+      proof_tx_not_found: 'Transaction not found',
+      proof_error: 'Verification error',
+      status_paid: 'Paid'
    }
  };

--- a/index.html
+++ b/index.html
@@ -73,34 +73,32 @@
        <a class="btn btn-secondary" id="openWallet" href="#" data-i18n="btn_open_wallet"></a>
        <button class="btn btn-secondary" id="copyAddr" data-i18n="btn_copy_addr"></button>
      </div>
-      <!-- Payment Monitor (v2) -->
-      <div class="monitor-section" id="monitorSection">
-        <button class="btn btn-monitor" id="monitorToggle">
+      <!-- TX Proof Verification -->
+      <div class="proof-section" id="proofSection">
+        <button class="btn btn-monitor" id="proofToggle">
          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
-            <rect x="3" y="11" width="18" height="11" rx="2" ry="2"/>
-            <path d="M7 11V7a5 5 0 0 1 10 0v4"/>
+            <path d="M22 11.08V12a10 10 0 1 1-5.93-9.14"/>
+            <polyline points="22 4 12 14.01 9 11.01"/>
          </svg>
-          <span data-i18n="btn_monitor"></span>
+          <span data-i18n="btn_prove_payment"></span>
        </button>
-        <div class="monitor-panel" id="monitorPanel">
+        <div class="proof-panel" id="proofPanel">
          <div class="field">
-            <label for="viewKey" data-i18n="label_view_key"></label>
-            <input type="text" id="viewKey" data-i18n-placeholder="placeholder_view_key" spellcheck="false" autocomplete="off" class="mono-masked">
-            <div class="view-key-hint" data-i18n="hint_view_key"></div>
+            <label for="txHash" data-i18n="label_tx_hash"></label>
+            <input type="text" id="txHash" data-i18n-placeholder="placeholder_tx_hash" spellcheck="false" autocomplete="off">
          </div>
-          <button class="btn btn-primary" id="startMonitor" disabled data-i18n="btn_start_monitor"></button>
-          <div class="monitor-status" id="monitorStatus">
-            <div class="status-indicator" id="statusIndicator"></div>
-            <div class="status-text" id="statusText"></div>
-            <div class="confirmations-bar" id="confirmationsBar">
-              <div class="confirmations-fill" id="confirmationsFill"></div>
-              <span class="confirmations-text" id="confirmationsText"></span>
-            </div>
-          </div>
-          <button class="btn btn-secondary" id="stopMonitor" data-i18n="btn_stop_monitor"></button>
+          <div class="field">
+            <label for="txKey" data-i18n="label_tx_key"></label>
+            <input type="text" id="txKey" data-i18n-placeholder="placeholder_tx_key" spellcheck="false" autocomplete="off">
+          </div>
+          <button class="btn btn-primary" id="verifyProof" disabled data-i18n="btn_verify_proof"></button>
+          <div class="proof-result" id="proofResult"></div>
        </div>
      </div>

+      <!-- Payment status (shown when proof is stored) -->
+      <div class="payment-status" id="paymentStatus"></div>
+
      <button class="btn btn-primary btn-new" id="newRequest" data-i18n="btn_new_request"></button>
    </div>
  </main>
@@ -126,6 +124,5 @@
  <script src="lib/qrcode.min.js"></script>
  <script src="i18n.js"></script>
  <script src="app.js"></script>
-  <script src="monitor.js"></script>
 </body>
 </html>
--- a/monitor.js
+++ b/monitor.js
@@ -1,422 +0,0 @@
-/**
- * monitor.js — Monero Payment Monitor (v2)
- * Uses XmrCrypto (noble-curves bundle) for output scanning.
- * View key never leaves the browser.
- */
-var PaymentMonitor = (function () {
-  'use strict';
-
-  var STATE = {
-    IDLE: 'idle',
-    CONNECTING: 'connecting',
-    SCANNING: 'scanning',
-    WAITING: 'waiting',
-    MEMPOOL: 'mempool',
-    CONFIRMED: 'confirmed',
-    UNDERPAID: 'underpaid',
-    ERROR: 'error'
-  };
-
-  var config = {
-    pollInterval: 30000,     // 30s mempool polling
-    confirmPoll: 30000,      // 30s confirmation polling
-    maxConfirmations: 10,
-    proxyUrl: '/api/node.php'
-  };
-
-  var state = STATE.IDLE;
-  var pollTimer = null;
-  var abortController = null;
-  var onStateChange = null;
-
-  // Monitoring params
-  var monitorAddr = null;
-  var monitorViewKey = null;
-  var monitorSpendKey = null;
-  var monitorViewKeyPub = null;
-  var expectedAmount = null; // in piconero (bigint)
-  var startHeight = 0;
-  var detectedTxHash = null;
-  var detectedAmount = 0n;
-  var lastConfirmations = 0;
-
-  function setState(newState, data) {
-    state = newState;
-    if (onStateChange) onStateChange(newState, data);
-  }
-
-  async function rpc(method, params) {
-    if (abortController && abortController.signal.aborted) throw new Error('Aborted');
-
-    var res = await fetch(config.proxyUrl, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({ method: method, params: params || {} }),
-      signal: abortController ? abortController.signal : undefined
-    });
-
-    if (!res.ok) throw new Error('RPC error: HTTP ' + res.status);
-    return res.json();
-  }
-
-  function start(address, privateViewKey, expectedXmr, callback) {
-    if (state !== STATE.IDLE) stop();
-
-    onStateChange = callback;
-    monitorAddr = address;
-    monitorViewKey = privateViewKey;
-    expectedAmount = xmrToPiconero(expectedXmr);
-    detectedTxHash = null;
-    detectedAmount = 0n;
-    lastConfirmations = 0;
-    abortController = new AbortController();
-
-    // Derive public keys from address
-    try {
-      var keys = XmrCrypto.getKeysFromAddress(address);
-      monitorSpendKey = keys.publicSpendKey;
-      monitorViewKeyPub = keys.publicViewKey;
-
-
-    } catch (e) {
-      setState(STATE.ERROR, { message: 'Invalid address' });
-      return;
-    }
-
-    // Validate view key against address (works for both standard and subaddress)
-    try {
-      var valid = XmrCrypto.validateViewKey(address, privateViewKey);
-
-      if (!valid) {
-        setState(STATE.ERROR, { message: I18n.t('monitor_view_key_invalid') });
-        return;
-      }
-    } catch (e) {
-      console.error('[monitor] View key validation error:', e);
-      setState(STATE.ERROR, { message: I18n.t('monitor_view_key_invalid') });
-      return;
-    }
-
-    setState(STATE.CONNECTING);
-    connectAndPoll();
-  }
-
-  async function connectAndPoll() {
-    try {
-      // Get current height
-      var info = await rpc('get_info');
-      var result = info.result || info;
-      // Scan 100 blocks back (~3.3 hours) to catch confirmed payments
-      startHeight = (result.height || result.target_height || 0) - 100;
-
-      setState(STATE.WAITING);
-      poll();
-      pollTimer = setInterval(poll, config.pollInterval);
-    } catch (e) {
-      setState(STATE.ERROR, { message: I18n.t('monitor_node_error') });
-      // Retry after delay
-      pollTimer = setTimeout(function () {
-        if (state === STATE.ERROR) connectAndPoll();
-      }, 5000);
-    }
-  }
-
-  async function poll() {
-    if (state === STATE.CONFIRMED) return;
-
-    try {
-      if (detectedTxHash) {
-        // We already found a TX, check confirmations
-        await checkConfirmations();
-      } else {
-        setState(STATE.SCANNING);
-
-        // Scan recent blocks first (catches already confirmed payments)
-        await scanRecentBlocks();
-
-        // Then scan mempool for unconfirmed payments
-        if (!detectedTxHash) {
-          await scanMempool();
-        }
-
-        if (!detectedTxHash) {
-          setState(STATE.WAITING);
-        }
-      }
-    } catch (e) {
-      if (e.name !== 'AbortError') {
-        console.warn('Monitor poll error:', e);
-      }
-    }
-  }
-
-  async function scanMempool() {
-    var pool = await rpc('get_transaction_pool');
-    var transactions = pool.transactions || [];
-
-    for (var i = 0; i < transactions.length; i++) {
-      var tx = transactions[i];
-      var txJson = tx.tx_json ? JSON.parse(tx.tx_json) : null;
-      if (!txJson) continue;
-
-      var match = scanTransaction(txJson, tx.id_hash);
-      if (match) {
-        detectedTxHash = match.txHash;
-        detectedAmount = match.amount;
-        reportDetection(0);
-        // Switch to confirmation polling
-        clearInterval(pollTimer);
-        pollTimer = setInterval(poll, config.confirmPoll);
-        return;
-      }
-    }
-  }
-
-  async function scanRecentBlocks() {
-    try {
-      var info = await rpc('get_info');
-      var result = info.result || info;
-      var currentHeight = result.height || 0;
-
-      var fromHeight = Math.max(startHeight, currentHeight - 100);
-      var batchSize = 10;
-
-      for (var batchStart = fromHeight; batchStart < currentHeight; batchStart += batchSize) {
-        var batchEnd = Math.min(batchStart + batchSize, currentHeight);
-        var allTxHashes = [];
-        var txHeightMap = {};
-
-        // Fetch blocks in this batch
-        for (var h = batchStart; h < batchEnd; h++) {
-          var blockData = await rpc('get_block', { height: h });
-          var blockResult = blockData.result || blockData;
-          var hashes = blockResult.tx_hashes || [];
-          for (var i = 0; i < hashes.length; i++) {
-            allTxHashes.push(hashes[i]);
-            txHeightMap[hashes[i]] = h;
-          }
-        }
-
-        if (allTxHashes.length === 0) continue;
-
-
-        // Fetch transactions in small sub-batches (restricted nodes limit response size)
-        var txBatchSize = 25;
-        for (var tbi = 0; tbi < allTxHashes.length; tbi += txBatchSize) {
-          var subBatch = allTxHashes.slice(tbi, tbi + txBatchSize);
-          var txData = await rpc('gettransactions', {
-            txs_hashes: subBatch,
-            decode_as_json: true
-          });
-
-          var txs = txData.txs || [];
-          if (txs.length === 0) {
-
-            continue;
-          }
-
-          for (var j = 0; j < txs.length; j++) {
-            var tx = txs[j];
-            var txJson = tx.as_json ? JSON.parse(tx.as_json) : null;
-            if (!txJson) continue;
-
-            var match = scanTransaction(txJson, tx.tx_hash);
-            if (match) {
-              detectedTxHash = match.txHash;
-              detectedAmount = match.amount;
-              var txHeight = txHeightMap[tx.tx_hash] || 0;
-              var confirmations = txHeight > 0 ? currentHeight - txHeight : 0;
-              reportDetection(confirmations);
-              clearInterval(pollTimer);
-              if (confirmations < config.maxConfirmations) {
-                pollTimer = setInterval(poll, config.confirmPoll);
-              }
-              return;
-            }
-          }
-        }
-      }
-    } catch (e) {
-      console.warn('Block scan error:', e);
-    }
-  }
-
-  function scanTransaction(txJson, txHash) {
-    // Extract tx public keys from extra
-    var extraHex = '';
-    if (txJson.extra) {
-      if (typeof txJson.extra === 'string') {
-        extraHex = txJson.extra;
-      } else if (Array.isArray(txJson.extra)) {
-        extraHex = txJson.extra.map(function (b) {
-          return ('0' + (b & 0xff).toString(16)).slice(-2);
-        }).join('');
-      }
-    }
-
-    var txPubKeys = XmrCrypto.parseTxExtra(extraHex);
-    if (txPubKeys.length === 0) {
-
-      return null;
-    }
-
-    // Get outputs
-    var outputs = [];
-    if (txJson.vout) {
-      outputs = txJson.vout;
-    }
-
-    // Get encrypted amounts from RingCT
-    var ecdhInfo = [];
-    if (txJson.rct_signatures && txJson.rct_signatures.ecdhInfo) {
-      ecdhInfo = txJson.rct_signatures.ecdhInfo;
-    }
-
-
-
-    var totalAmount = 0n;
-    var found = false;
-
-    for (var ki = 0; ki < txPubKeys.length; ki++) {
-      var txPubKey = txPubKeys[ki];
-
-      for (var oi = 0; oi < outputs.length; oi++) {
-        var out = outputs[oi];
-        var outputKey = null;
-
-        if (out.target && out.target.tagged_key) {
-          outputKey = out.target.tagged_key.key;
-        } else if (out.target && out.target.key) {
-          outputKey = out.target.key;
-        }
-
-        if (!outputKey) continue;
-
-        var encryptedAmount = null;
-        if (ecdhInfo[oi] && ecdhInfo[oi].amount) {
-          encryptedAmount = ecdhInfo[oi].amount;
-        }
-
-        try {
-          var result = XmrCrypto.checkOutput(
-            txPubKey, oi, outputKey, encryptedAmount,
-            monitorViewKey, monitorSpendKey
-          );
-
-          if (result.match) {
-
-            totalAmount += result.amount;
-            found = true;
-          }
-        } catch (e) {
-        }
-      }
-    }
-
-    if (found) {
-      return { txHash: txHash, amount: totalAmount };
-    }
-    return null;
-  }
-
-  function reportDetection(confirmations) {
-    lastConfirmations = confirmations;
-
-    if (expectedAmount > 0n && detectedAmount < expectedAmount) {
-      setState(STATE.UNDERPAID, {
-        expected: piconeroToXmr(expectedAmount),
-        received: piconeroToXmr(detectedAmount),
-        confirmations: confirmations,
-        txHash: detectedTxHash
-      });
-    } else if (confirmations >= config.maxConfirmations) {
-      setState(STATE.CONFIRMED, {
-        amount: piconeroToXmr(detectedAmount),
-        confirmations: confirmations,
-        txHash: detectedTxHash
-      });
-    } else {
-      setState(STATE.MEMPOOL, {
-        amount: piconeroToXmr(detectedAmount),
-        confirmations: confirmations,
-        txHash: detectedTxHash
-      });
-    }
-  }
-
-  async function checkConfirmations() {
-    try {
-      var txData = await rpc('gettransactions', {
-        txs_hashes: [detectedTxHash],
-        decode_as_json: true
-      });
-
-      var txs = txData.txs || [];
-      if (txs.length === 0) return;
-
-      var tx = txs[0];
-      var confirmations = 0;
-
-      if (tx.in_pool) {
-        confirmations = 0;
-      } else if (tx.block_height) {
-        var info = await rpc('get_info');
-        var result = info.result || info;
-        var currentHeight = result.height || 0;
-        confirmations = currentHeight - tx.block_height;
-      }
-
-      reportDetection(confirmations);
-
-      if (confirmations >= config.maxConfirmations) {
-        clearInterval(pollTimer);
-        pollTimer = null;
-      }
-    } catch (e) {
-      console.warn('Confirmation check error:', e);
-    }
-  }
-
-  function stop() {
-    if (pollTimer) {
-      clearInterval(pollTimer);
-      clearTimeout(pollTimer);
-      pollTimer = null;
-    }
-    if (abortController) {
-      abortController.abort();
-      abortController = null;
-    }
-    state = STATE.IDLE;
-    monitorViewKey = null;
-    monitorSpendKey = null;
-    detectedTxHash = null;
-    detectedAmount = 0n;
-    onStateChange = null;
-  }
-
-  function xmrToPiconero(xmr) {
-    if (!xmr || xmr <= 0) return 0n;
-    return BigInt(Math.round(xmr * 1e12));
-  }
-
-  function piconeroToXmr(piconero) {
-    return Number(piconero) / 1e12;
-  }
-
-  function isValidViewKey(key) {
-    return /^[0-9a-fA-F]{64}$/.test(key);
-  }
-
-  function getState() {
-    return state;
-  }
-
-  return {
-    start: start,
-    stop: stop,
-    isValidViewKey: isValidViewKey,
-    getState: getState,
-    STATE: STATE
-  };
-})();
--- a/s.php
+++ b/s.php
@@ -22,7 +22,7 @@ if (!isset($urls[$code])) {
    exit;
 }

-$hash = $urls[$code];
+$hash = $urls[$code]['hash'] ?? $urls[$code];
 $base = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? 'https' : 'http') . '://' . $_SERVER['HTTP_HOST'];
-header('Location: ' . $base . '/#' . $hash, true, 302);
+header('Location: ' . $base . '/#' . $hash . '&c=' . $code, true, 302);
 exit;
--- a/style.css
+++ b/style.css
@@ -407,9 +407,9 @@ textarea {
  flex: 1;
 }

-/* --- Monitor Section --- */
+/* --- TX Proof Section --- */

-.monitor-section {
+.proof-section {
  margin-top: 1rem;
  border-top: 1px solid var(--border);
  padding-top: 0.8rem;
@@ -438,123 +438,64 @@ textarea {
  color: var(--text);
 }

-.monitor-panel {
+.proof-panel {
  display: none;
  margin-top: 0.8rem;
 }

-.monitor-panel.open {
+.proof-panel.open {
  display: block;
 }

-.mono-masked {
-  -webkit-text-security: disc;
-}
-
-.view-key-hint {
-  font-size: 0.7rem;
-  color: var(--text-muted);
-  margin-top: 0.25rem;
-  font-style: italic;
-}
-
-.monitor-status {
+.proof-result {
  display: none;
  text-align: center;
-  padding: 1rem 0;
+  padding: 0.8rem;
+  border-radius: var(--radius);
+  font-size: 0.85rem;
+  margin-top: 0.8rem;
 }

-.monitor-status.active {
+.proof-result.active {
  display: block;
 }

-.status-indicator {
-  width: 12px;
-  height: 12px;
-  border-radius: 50%;
-  margin: 0 auto 0.5rem;
-  background: var(--text-muted);
+.proof-result.success {
+  background: rgba(76, 175, 80, 0.15);
+  color: var(--success);
+  border: 1px solid var(--success);
 }

-.status-indicator.connecting,
-.status-indicator.scanning {
-  background: var(--accent);
-  animation: pulse 1.5s ease-in-out infinite;
+.proof-result.error {
+  background: rgba(244, 67, 54, 0.15);
+  color: var(--error);
+  border: 1px solid var(--error);
 }

-.status-indicator.waiting {
-  background: var(--accent);
-  animation: pulse 2s ease-in-out infinite;
+.payment-status {
+  display: none;
 }

-.status-indicator.mempool {
-  background: #ffc107;
-  animation: pulse 1s ease-in-out infinite;
+.payment-status.paid {
+  display: block;
+  text-align: center;
+  margin-top: 1rem;
 }

-.status-indicator.confirmed {
+.paid-badge {
+  display: inline-block;
  background: var(--success);
-  animation: none;
-}
-
-.status-indicator.underpaid {
-  background: var(--error);
-  animation: pulse 1s ease-in-out infinite;
-}
-
-.status-indicator.error {
-  background: var(--error);
-}
-
-@keyframes pulse {
-  0%, 100% { opacity: 1; transform: scale(1); }
-  50% { opacity: 0.5; transform: scale(1.2); }
-}
-
-.status-text {
-  font-size: 0.9rem;
-  color: var(--text);
-  margin-bottom: 0.5rem;
-}
-
-.confirmations-bar {
-  display: none;
-  position: relative;
-  height: 24px;
-  background: var(--bg-input);
+  color: #fff;
+  padding: 0.4rem 1.2rem;
  border-radius: var(--radius);
-  overflow: hidden;
-  margin-bottom: 0.8rem;
+  font-weight: 700;
+  font-size: 1rem;
+  margin-bottom: 0.3rem;
 }

-.confirmations-bar.active {
-  display: block;
-}
-
-.confirmations-fill {
-  height: 100%;
-  background: linear-gradient(90deg, var(--accent), var(--success));
-  border-radius: var(--radius);
-  transition: width 0.5s ease;
-  width: 0%;
-}
-
-.confirmations-text {
-  position: absolute;
-  top: 50%;
-  left: 50%;
-  transform: translate(-50%, -50%);
+.paid-detail {
  font-size: 0.75rem;
-  font-weight: 600;
-  color: var(--text);
-}
-
-#stopMonitor {
-  display: none;
-}
-
-#stopMonitor.active {
-  display: block;
+  color: var(--text-muted);
 }

 .btn-new {
--- a/sw.js
+++ b/sw.js
@@ -1,10 +1,9 @@
-var CACHE_NAME = 'xmrpay-v2';
+var CACHE_NAME = 'xmrpay-v3';
 var ASSETS = [
  '/',
  '/index.html',
  '/app.js',
  '/i18n.js',
-  '/monitor.js',
  '/style.css',
  '/lib/qrcode.min.js'
  // xmr-crypto.bundle.js is lazy-loaded and runtime-cached