BIP87

basicswap/basicswap.py

@@ -2428,13 +2428,6 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
 
     def _syncLiteWalletToRPCOnStartup(self, coin_type: Coins) -> None:
         try:
-            cc = self.coin_clients[coin_type]
-            if not cc.get("auto_transfer_on_mode_switch", True):
-                self.log.debug(
-                    f"Auto-transfer disabled for {getCoinName(coin_type)}, skipping sweep check"
-                )
-                return
-
             cursor = self.openDB()
             try:
                 row = cursor.execute(
@@ -2780,6 +2773,137 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
             self.log.error(f"_transferLiteWalletBalanceToRPC error: {e}")
             return None
 
+    def sweepLiteWalletFunds(self, coin_type: Coins) -> dict:
+        try:
+            coin_name = getCoinName(coin_type)
+            self.log.info(f"Manual sweep requested for {coin_name}")
+
+            if coin_type in WalletManager.SUPPORTED_COINS:
+                if not self._wallet_manager.isInitialized(coin_type):
+                    try:
+                        self.initializeWalletManager(coin_type)
+                    except Exception as e:
+                        return {
+                            "success": False,
+                            "error": f"Wallet locked: {e}",
+                        }
+
+            result = self._transferLiteWalletBalanceToRPC(coin_type)
+            if result is None:
+                return {"skipped": True, "reason": "No balance to sweep"}
+            if result.get("skipped"):
+                return result
+            if result.get("txid"):
+                return {
+                    "success": True,
+                    "txid": result["txid"],
+                    "amount": result.get("amount", 0) / 1e8,
+                    "fee": result.get("fee", 0) / 1e8,
+                    "address": result.get("address", ""),
+                }
+            if result.get("error"):
+                return {"success": False, "error": result["error"]}
+            return {"skipped": True, "reason": "Unknown result"}
+        except Exception as e:
+            self.log.error(
+                f"sweepLiteWalletFunds error for {getCoinName(coin_type)}: {e}"
+            )
+            return {"success": False, "error": str(e)}
+
+    def _consolidateLegacyFundsToSegwit(self, coin_type: Coins) -> dict:
+        try:
+            coin_name = getCoinName(coin_type)
+            cc = self.coin_clients[coin_type]
+            ci = cc.get("interface")
+            if not ci:
+                return {"skipped": True, "reason": "No coin interface"}
+
+            try:
+                unspent = ci.rpc_wallet("listunspent")
+            except Exception as e:
+                return {"error": f"Failed to list UTXOs: {e}"}
+
+            hrp = ci.chainparams_network().get("hrp", "bc")
+            legacy_utxos = []
+            total_legacy_sats = 0
+
+            for u in unspent:
+                if "address" not in u:
+                    continue
+                addr = u["address"]
+                if not addr.startswith(hrp + "1"):
+                    legacy_utxos.append(u)
+                    total_legacy_sats += ci.make_int(u.get("amount", 0))
+
+            if not legacy_utxos:
+                return {"skipped": True, "reason": "No legacy funds found"}
+
+            if total_legacy_sats <= 0:
+                return {"skipped": True, "reason": "No balance on legacy addresses"}
+
+            est_vsize = len(legacy_utxos) * 150 + 40
+            fee_rate, _ = ci.get_fee_rate(ci._conf_target)
+            if isinstance(fee_rate, int):
+                fee_per_vbyte = max(1, fee_rate // 1000)
+            else:
+                fee_per_vbyte = max(1, int(fee_rate * 100000))
+            estimated_fee_sats = est_vsize * fee_per_vbyte
+
+            if total_legacy_sats <= estimated_fee_sats * 2:
+                return {
+                    "skipped": True,
+                    "reason": f"Legacy balance ({total_legacy_sats}) too low for fee ({estimated_fee_sats})",
+                }
+
+            try:
+                new_address = ci.rpc_wallet("getnewaddress", ["consolidate", "bech32"])
+            except Exception as e:
+                return {"error": f"Failed to get new address: {e}"}
+
+            send_amount_sats = total_legacy_sats - estimated_fee_sats
+            send_amount_btc = ci.format_amount(send_amount_sats)
+
+            self.log.info(
+                f"[Consolidate {coin_name}] Moving {ci.format_amount(total_legacy_sats)} from "
+                f"{len(legacy_utxos)} legacy UTXOs to {new_address}"
+            )
+
+            inputs = [{"txid": u["txid"], "vout": u["vout"]} for u in legacy_utxos]
+
+            try:
+                raw_tx = ci.rpc_wallet(
+                    "createrawtransaction",
+                    [inputs, {new_address: float(send_amount_btc)}],
+                )
+            except Exception as e:
+                return {"error": f"Failed to create transaction: {e}"}
+
+            try:
+                signed = ci.rpc_wallet("signrawtransactionwithwallet", [raw_tx])
+                if not signed.get("complete"):
+                    return {"error": "Failed to sign transaction"}
+                txid = ci.rpc_wallet("sendrawtransaction", [signed["hex"]])
+            except Exception as e:
+                return {"error": f"Failed to broadcast transaction: {e}"}
+
+            self.log.info(f"[Consolidate {coin_name}] SUCCESS! TXID: {txid}")
+
+            return {
+                "success": True,
+                "txid": txid,
+                "amount": send_amount_sats / 1e8,
+                "fee": estimated_fee_sats / 1e8,
+                "address": new_address,
+                "num_inputs": len(legacy_utxos),
+            }
+
+        except Exception as e:
+            self.log.error(f"_consolidateLegacyFundsToSegwit error: {e}")
+            import traceback
+
+            self.log.debug(traceback.format_exc())
+            return {"error": str(e)}
+
     def _retryPendingSweeps(self) -> None:
         if not self._pending_sweeps:
             return
@@ -2869,6 +2993,43 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
             self.log.debug(f"getLiteWalletBalanceInfo error: {e}")
             return None
 
+    def getElectrumLegacyFundsInfo(self, coin_type: Coins) -> dict:
+        try:
+            cc = self.coin_clients.get(coin_type)
+            if not cc or cc.get("connection_type") != "electrum":
+                return {"has_legacy_funds": False}
+
+            if not self._wallet_manager:
+                return {"has_legacy_funds": False}
+
+            ci = self.ci(coin_type)
+            hrp = ci.chainparams_network().get("hrp", "bc")
+
+            unspent_by_addr = ci.getUnspentsByAddr()
+            if not unspent_by_addr:
+                return {"has_legacy_funds": False}
+
+            legacy_balance_sats = 0
+            legacy_addresses = []
+
+            for addr, balance_sats in unspent_by_addr.items():
+                if not addr.startswith(hrp + "1"):
+                    legacy_balance_sats += balance_sats
+                    legacy_addresses.append(addr)
+
+            if legacy_balance_sats > 0:
+                return {
+                    "has_legacy_funds": True,
+                    "legacy_balance_sats": legacy_balance_sats,
+                    "legacy_balance": ci.format_amount(legacy_balance_sats),
+                    "legacy_address_count": len(legacy_addresses),
+                    "coin": ci.ticker_mainnet(),
+                }
+            return {"has_legacy_funds": False}
+        except Exception as e:
+            self.log.debug(f"getElectrumLegacyFundsInfo error: {e}")
+            return {"has_legacy_funds": False}
+
     def _tryGetFullNodeAddresses(self, coin_type: Coins) -> list:
         addresses = []
         try:
@@ -13089,15 +13250,39 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
                 display_name = getCoinName(coin_id)
 
                 if old_connection_type == "rpc" and new_connection_type == "electrum":
+                    auto_transfer_now = data.get("auto_transfer_now", False)
+                    if auto_transfer_now:
+                        transfer_result = self._consolidateLegacyFundsToSegwit(coin_id)
+                        if transfer_result.get("success"):
+                            self.log.info(
+                                f"Consolidated {transfer_result.get('amount', 0):.8f} {display_name} "
+                                f"from legacy addresses. TXID: {transfer_result.get('txid')}"
+                            )
+                            if migration_message:
+                                migration_message += f" Transferred {transfer_result.get('amount', 0):.8f} {display_name} to native segwit."
+                            else:
+                                migration_message = f"Transferred {transfer_result.get('amount', 0):.8f} {display_name} to native segwit."
+                        elif transfer_result.get("skipped"):
+                            self.log.info(
+                                f"Legacy fund transfer skipped for {coin_name}: {transfer_result.get('reason')}"
+                            )
+                        elif transfer_result.get("error"):
+                            self.log.warning(
+                                f"Legacy fund transfer warning for {coin_name}: {transfer_result.get('error')}"
+                            )
+
                     migration_result = self._migrateWalletToLiteMode(coin_id)
                     if migration_result.get("success"):
                         count = migration_result.get("count", 0)
                         self.log.info(
                             f"Lite wallet ready for {coin_name} with {count} addresses"
                         )
-                        migration_message = (
+                        if migration_message:
-                            f"Lite wallet ready for {display_name} ({count} addresses)."
+                            migration_message += (
+                                f" Lite wallet ready ({count} addresses)."
                             )
+                        else:
+                            migration_message = f"Lite wallet ready for {display_name} ({count} addresses)."
                     else:
                         error = migration_result.get("error", "unknown")
                         reason = migration_result.get("reason", "")
@@ -13120,11 +13305,38 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
 
                     empty_check = self._checkElectrumWalletEmpty(coin_id)
                     if not empty_check.get("empty", False):
+                        reason = empty_check.get("reason", "")
+
+                        auto_transfer_now = data.get("auto_transfer_now", False)
+
+                        if reason == "has_balance" and auto_transfer_now:
+                            self.log.info(
+                                f"Auto-transfer requested for {coin_name} during mode switch"
+                            )
+                            sweep_result = self.sweepLiteWalletFunds(coin_id)
+                            if sweep_result.get("success"):
+                                self.log.info(
+                                    f"Swept {sweep_result.get('amount', 0):.8f} {display_name} "
+                                    f"to RPC wallet. TXID: {sweep_result.get('txid')}"
+                                )
+                                migration_message = (
+                                    f"Transferred {sweep_result.get('amount', 0):.8f} {display_name} "
+                                    f"to full node wallet."
+                                )
+                            elif sweep_result.get("skipped"):
+                                self.log.info(
+                                    f"Sweep skipped for {coin_name}: {sweep_result.get('reason')}"
+                                )
+                            else:
+                                error = sweep_result.get("error", "Transfer failed")
+                                self.log.error(
+                                    f"Transfer failed for {coin_name}: {error}"
+                                )
+                                raise ValueError(f"Transfer failed: {error}")
+                        elif reason in ("has_balance", "active_swap"):
                             error = empty_check.get(
                                 "message", "Wallet must be empty before switching modes"
                             )
-                        reason = empty_check.get("reason", "")
-                        if reason in ("has_balance", "active_swap"):
                             self.log.error(
                                 f"Migration blocked for {coin_name}: {error}"
                             )
@@ -13281,19 +13493,6 @@ class BasicSwap(BaseApp, BSXNetwork, UIApp):
                             cc["electrum_onion_servers"] = new_onion
                             break
 
-            if "auto_transfer_on_mode_switch" in data:
-                new_auto_transfer = data["auto_transfer_on_mode_switch"]
-                if (
-                    settings_cc.get("auto_transfer_on_mode_switch", True)
-                    != new_auto_transfer
-                ):
-                    settings_changed = True
-                    settings_cc["auto_transfer_on_mode_switch"] = new_auto_transfer
-                    for coin, cc in self.coin_clients.items():
-                        if cc["name"] == coin_name:
-                            cc["auto_transfer_on_mode_switch"] = new_auto_transfer
-                            break
-
             if settings_changed:
                 self._normalizeSettingsPaths(settings_copy)
                 settings_path = os.path.join(self.data_dir, cfg.CONFIG_FILENAME)

basicswap/bin/prepare.py

@@ -1841,6 +1841,7 @@ def initialise_wallets(
     daemons = []
     daemon_args = ["-noconnect", "-nodnsseed"]
     generated_mnemonic: bool = False
+    extended_keys = {}
 
     coins_failed_to_initialise = []
 
@@ -2098,6 +2099,20 @@ def initialise_wallets(
                 except Exception as e:  # noqa: F841
                     logger.warning(f"changeWalletPassword failed for {coin_name}.")
 
+        zprv_prefix = 0x04B2430C if chain == "mainnet" else 0x045F18BC
+        for coin_name in with_coins:
+            c = swap_client.getCoinIdFromName(coin_name)
+            if c == Coins.PART:
+                continue
+            try:
+                ci = swap_client.ci(c)
+                if hasattr(ci, "canExportToElectrum") and ci.canExportToElectrum():
+                    seed_key = swap_client.getWalletKey(c, 1)
+                    account_key = ci.getAccountKey(seed_key, zprv_prefix)
+                    extended_keys[getCoinName(c)] = account_key
+            except Exception as e:
+                logger.debug(f"Could not generate extended key for {coin_name}: {e}")
+
     finally:
         if swap_client:
             swap_client.finalise()
@@ -2129,6 +2144,18 @@ def initialise_wallets(
                 )
             )
 
+            if extended_keys:
+                print("Extended private keys (for external wallet import):")
+                for coin_name, key in extended_keys.items():
+                    print(f"  {coin_name}: {key}")
+                print("")
+                print(
+                    "NOTE: These keys can be imported into Electrum using 'Use a master key'."
+                )
+                print("WARNING: Write these down NOW. They will not be shown again.\n")
+
+    return extended_keys
+
 
 def load_config(config_path):
     if not os.path.exists(config_path):
@@ -3071,7 +3098,7 @@ def main():
                 )
 
                 if particl_wallet_mnemonic != "none":
-                    initialise_wallets(
+                    extended_keys = initialise_wallets(
                         None,
                         {
                             add_coin,
@@ -3083,6 +3110,18 @@ def main():
                         extra_opts=extra_opts,
                     )
 
+                    if extended_keys:
+                        print("\nExtended private key (for external wallet import):")
+                        for coin_name, key in extended_keys.items():
+                            print(f"  {coin_name}: {key}")
+                        print("")
+                        print(
+                            "NOTE: This key can be imported into Electrum using 'Use a master key'."
+                        )
+                        print(
+                            "WARNING: Write this down NOW. It will not be shown again.\n"
+                        )
+
                 save_config(config_path, settings)
         finally:
             if "particl_daemon" in extra_opts:

basicswap/interface/btc.py

@@ -3355,7 +3355,8 @@ class BTCInterface(Secp256k1Interface):
             total_balance = sum(u.get("value", 0) for u in all_utxos)
 
             est_vsize = 10 + 31 + len(all_utxos) * 68
-            est_fee = est_vsize * fee_per_vbyte
+            min_fee = 250
+            est_fee = max(est_vsize * fee_per_vbyte, min_fee)
 
             if total_balance <= est_fee:
                 raise ValueError(

basicswap/js_server.py

@@ -1248,10 +1248,12 @@ def js_getcoinseed(self, url_split, post_string, is_json) -> bytes:
                 "current_seed_id": wallet_seed_id,
             }
         )
-        if hasattr(ci, "canExportToElectrum") and ci.canExportToElectrum():
+
-            rv.update(
+        if hasattr(ci, "getAccountKey"):
-                {"account_key": ci.getAccountKey(seed_key, extkey_prefix)}
+            try:
-            )  # Master key can be imported into electrum (Must set prefix for P2WPKH)
+                rv.update({"account_key": ci.getAccountKey(seed_key, extkey_prefix)})
+            except Exception as e:
+                rv.update({"account_key_error": str(e)})
 
     return bytes(
         json.dumps(rv),
@@ -1674,6 +1676,97 @@ def js_messageroutes(self, url_split, post_string, is_json) -> bytes:
     return bytes(json.dumps(message_routes), "UTF-8")
 
 
+def js_modeswitchinfo(self, url_split, post_string, is_json) -> bytes:
+    swap_client = self.server.swap_client
+    swap_client.checkSystemStatus()
+    post_data = getFormData(post_string, is_json)
+
+    coin_str = get_data_entry(post_data, "coin")
+    direction = get_data_entry_or(post_data, "direction", "lite")
+
+    try:
+        coin_type = getCoinIdFromName(coin_str)
+    except Exception:
+        coin_type = getCoinIdFromTicker(coin_str.upper())
+
+    ci = swap_client.ci(coin_type)
+    ticker = ci.ticker()
+
+    try:
+        wallet_info = ci.getWalletInfo()
+        balance = wallet_info.get("balance", 0)
+        balance_sats = ci.make_int(balance)
+    except Exception as e:
+        return bytes(json.dumps({"error": f"Failed to get balance: {e}"}), "UTF-8")
+
+    try:
+        fee_rate, rate_src = ci.get_fee_rate(ci._conf_target)
+        est_vsize = 180
+        if isinstance(fee_rate, int):
+            fee_per_vbyte = max(1, fee_rate // 1000)
+        else:
+            fee_per_vbyte = max(1, int(fee_rate * 100000))
+        estimated_fee_sats = est_vsize * fee_per_vbyte
+    except Exception:
+        estimated_fee_sats = 180
+        rate_src = "default"
+
+    min_viable = estimated_fee_sats * 2
+    can_transfer = balance_sats > min_viable
+
+    rv = {
+        "coin": ticker,
+        "direction": direction,
+        "balance": balance,
+        "balance_sats": balance_sats,
+        "estimated_fee_sats": estimated_fee_sats,
+        "estimated_fee": ci.format_amount(estimated_fee_sats),
+        "fee_rate_src": rate_src,
+        "can_transfer": can_transfer,
+        "min_viable_sats": min_viable,
+    }
+
+    if direction == "lite":
+        legacy_balance_sats = 0
+        has_legacy_funds = False
+        try:
+            if hasattr(ci, "rpc_wallet"):
+                unspent = ci.rpc_wallet("listunspent")
+                hrp = ci.chainparams_network().get("hrp", "bc")
+                for u in unspent:
+                    if "address" in u and not u["address"].startswith(hrp + "1"):
+                        legacy_balance_sats += ci.make_int(u.get("amount", 0))
+                        has_legacy_funds = True
+        except Exception as e:
+            swap_client.log.debug(f"Error checking legacy addresses: {e}")
+
+        if has_legacy_funds and legacy_balance_sats > min_viable:
+            rv["show_transfer_option"] = True
+            rv["legacy_balance_sats"] = legacy_balance_sats
+            rv["legacy_balance"] = ci.format_amount(legacy_balance_sats)
+            rv["message"] = (
+                "Funds on legacy addresses - transfer recommended for external wallet compatibility"
+            )
+        else:
+            rv["show_transfer_option"] = False
+            rv["legacy_balance_sats"] = 0
+            rv["legacy_balance"] = "0"
+            if has_legacy_funds:
+                rv["message"] = "Legacy balance too low to transfer"
+            else:
+                rv["message"] = "All funds on native segwit addresses"
+    else:
+        rv["show_transfer_option"] = can_transfer
+        if balance_sats == 0:
+            rv["message"] = "No funds to transfer"
+        elif not can_transfer:
+            rv["message"] = "Balance too low to transfer (fee would exceed funds)"
+        else:
+            rv["message"] = ""
+
+    return bytes(json.dumps(rv), "UTF-8")
+
+
 def js_electrum_discover(self, url_split, post_string, is_json) -> bytes:
     swap_client = self.server.swap_client
     post_data = {} if post_string == "" else getFormData(post_string, is_json)
@@ -1805,6 +1898,7 @@ endpoints = {
     "coinhistory": js_coinhistory,
     "messageroutes": js_messageroutes,
     "electrumdiscover": js_electrum_discover,
+    "modeswitchinfo": js_modeswitchinfo,
 }
 
 

basicswap/static/js/pages/settings-page.js

@@ -147,6 +147,16 @@
             hiddenInput.name = submitter.name;
             hiddenInput.value = submitter.value;
             form.appendChild(hiddenInput);
+
+            const transferRadio = document.querySelector('input[name="transfer_choice"]:checked');
+            if (transferRadio) {
+              const transferInput = document.createElement('input');
+              transferInput.type = 'hidden';
+              transferInput.name = `auto_transfer_now_${coinName}`;
+              transferInput.value = transferRadio.value === 'auto' ? 'true' : 'false';
+              form.appendChild(transferInput);
+            }
+
             form.submit();
           }
         });
@@ -167,11 +177,26 @@
       }
     },
 
-    showWalletModeConfirmation: function(coinName, direction, submitter) {
+    updateConfirmButtonState: function() {
+      const confirmBtn = document.getElementById('walletModeConfirm');
+      const checkbox = document.getElementById('walletModeKeyConfirmCheckbox');
+      if (confirmBtn && checkbox) {
+        if (checkbox.checked) {
+          confirmBtn.disabled = false;
+          confirmBtn.classList.remove('opacity-50', 'cursor-not-allowed');
+        } else {
+          confirmBtn.disabled = true;
+          confirmBtn.classList.add('opacity-50', 'cursor-not-allowed');
+        }
+      }
+    },
+
+    showWalletModeConfirmation: async function(coinName, direction, submitter) {
       const modal = document.getElementById('walletModeModal');
       const title = document.getElementById('walletModeTitle');
       const message = document.getElementById('walletModeMessage');
       const details = document.getElementById('walletModeDetails');
+      const confirmBtn = document.getElementById('walletModeConfirm');
 
       if (!modal || !title || !message || !details) return;
 
@@ -179,37 +204,223 @@
 
       const displayName = coinName.charAt(0).toUpperCase() + coinName.slice(1).toLowerCase();
 
+      details.innerHTML = `
+        <div class="flex items-center justify-center py-4">
+          <svg class="animate-spin h-5 w-5 text-blue-500 mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
+            <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
+            <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
+          </svg>
+          <span>Loading...</span>
+        </div>
+      `;
+
+      if (confirmBtn) {
+        confirmBtn.disabled = true;
+        confirmBtn.classList.add('opacity-50', 'cursor-not-allowed');
+      }
+
+      modal.classList.remove('hidden');
+
       if (direction === 'lite') {
         title.textContent = `Switch ${displayName} to Lite Wallet Mode`;
-        message.textContent = 'Please confirm you want to switch to lite wallet mode.';
+        message.textContent = 'Write down this key before switching. It will only be shown ONCE.';
+
+        try {
+          const [infoResponse, seedResponse] = await Promise.all([
+            fetch('/json/modeswitchinfo', {
+              method: 'POST',
+              headers: { 'Content-Type': 'application/json' },
+              body: JSON.stringify({ coin: coinName, direction: 'lite' })
+            }),
+            fetch('/json/getcoinseed', {
+              method: 'POST',
+              headers: { 'Content-Type': 'application/json' },
+              body: JSON.stringify({ coin: coinName })
+            })
+          ]);
+          const info = await infoResponse.json();
+          const data = await seedResponse.json();
+
+          let transferSection = '';
+          if (info.show_transfer_option && info.legacy_balance_sats > 0) {
+            transferSection = `
+              <div class="bg-gray-200 dark:bg-gray-700 border border-gray-300 dark:border-gray-500 rounded-lg p-3 mb-3">
+                <p class="text-sm font-medium text-yellow-700 dark:text-yellow-300 mb-2">Legacy Address Funds Detected</p>
+                <p class="text-xs text-gray-700 dark:text-gray-300 mb-3">
+                  ${info.legacy_balance} ${info.coin} on legacy addresses won't be visible in external Electrum wallet.
+                  Est. fee: ${info.estimated_fee} ${info.coin}
+                </p>
+                <div class="space-y-2">
+                  <label class="flex items-start cursor-pointer hover:bg-gray-300 dark:hover:bg-gray-600 rounded p-1.5 -m-1">
+                    <input type="radio" name="transfer_choice" value="auto" class="mt-0.5 mr-2 h-4 w-4 text-blue-600 border-gray-400 dark:border-gray-400 focus:ring-blue-500 bg-white dark:bg-gray-500">
+                    <div>
+                      <span class="text-sm font-medium text-gray-900 dark:text-white">Transfer to native segwit address</span>
+                      <p class="text-xs text-gray-600 dark:text-gray-300">Recommended for external wallet compatibility.</p>
+                    </div>
+                  </label>
+                  <label class="flex items-start cursor-pointer hover:bg-gray-300 dark:hover:bg-gray-600 rounded p-1.5 -m-1">
+                    <input type="radio" name="transfer_choice" value="manual" checked class="mt-0.5 mr-2 h-4 w-4 text-blue-600 border-gray-400 dark:border-gray-400 focus:ring-blue-500 bg-white dark:bg-gray-500">
+                    <div>
+                      <span class="text-sm font-medium text-gray-900 dark:text-white">Keep on current addresses</span>
+                      <p class="text-xs text-gray-600 dark:text-gray-300">Funds accessible in BasicSwap, transfer manually later if needed.</p>
+                    </div>
+                  </label>
+                </div>
+                <p class="text-xs text-red-600 dark:text-red-400 mt-3">
+                  If you skip transfer, legacy funds won't be visible when importing the extended key into external Electrum wallet.
+                </p>
+              </div>
+            `;
+          } else if (info.legacy_balance_sats > 0 && !info.show_transfer_option) {
+            transferSection = `
+              <p class="text-yellow-700 dark:text-yellow-300 text-xs mb-3">
+                Some funds on legacy addresses (${info.legacy_balance} ${info.coin}) - too low to transfer.
+              </p>
+            `;
+          }
+
+          if (data.account_key) {
             details.innerHTML = `
-          <p class="mb-2"><strong>Before switching:</strong></p>
+              <p class="mb-2 text-red-600 dark:text-red-300 font-semibold">
-          <ul class="list-disc list-inside space-y-1">
+                IMPORTANT: Write down this key NOW. It will not be shown again.
+              </p>
+              <p class="mb-2 text-gray-800 dark:text-gray-100"><strong>Extended Private Key (for external wallet import):</strong></p>
+              <div class="bg-gray-50 dark:bg-gray-700 border border-gray-300 dark:border-gray-500 rounded p-2 mb-3">
+                <code class="text-xs break-all select-all font-mono text-gray-900 dark:text-gray-100">${data.account_key}</code>
+              </div>
+              <p class="text-xs text-gray-600 dark:text-gray-300 mb-3">
+                This key can be imported into Electrum using "Use a master key" option.
+              </p>
+              ${transferSection}
+              <div class="border-t border-gray-300 dark:border-gray-500 pt-3">
+                <label class="flex items-center cursor-pointer hover:bg-gray-200 dark:hover:bg-gray-500 rounded p-1 -m-1">
+                  <input type="checkbox" id="walletModeKeyConfirmCheckbox" class="mr-2 h-4 w-4 text-blue-600 rounded border-gray-300 dark:border-gray-500 focus:ring-blue-500 dark:bg-gray-700">
+                  <span class="text-sm font-medium text-gray-800 dark:text-gray-100">I have written down this key</span>
+                </label>
+              </div>
+            `;
+
+            const checkbox = document.getElementById('walletModeKeyConfirmCheckbox');
+            if (checkbox) {
+              checkbox.addEventListener('change', () => this.updateConfirmButtonState());
+            }
+          } else {
+            details.innerHTML = `
+              <p class="mb-2 text-gray-800 dark:text-gray-100"><strong>Before switching:</strong></p>
+              <ul class="list-disc list-inside space-y-1 text-gray-700 dark:text-gray-200">
                 <li>Active swaps must be completed first</li>
                 <li>Wait for any pending transactions to confirm</li>
               </ul>
-          <p class="mt-3 text-green-600 dark:text-green-400">
+              ${transferSection}
+              <p class="mt-3 text-green-700 dark:text-green-300">
                 <strong>Note:</strong> Your balance will remain accessible - same seed means same funds in both modes.
               </p>
             `;
+            if (confirmBtn) {
+              confirmBtn.disabled = false;
+              confirmBtn.classList.remove('opacity-50', 'cursor-not-allowed');
+            }
+          }
+        } catch (error) {
+          console.error('Failed to fetch coin seed:', error);
+          details.innerHTML = `
+            <p class="text-red-600 dark:text-red-300 mb-2">Failed to retrieve extended key. Please try again.</p>
+            <p class="mb-2 text-gray-800 dark:text-gray-100"><strong>Before switching:</strong></p>
+            <ul class="list-disc list-inside space-y-1 text-gray-700 dark:text-gray-200">
+              <li>Active swaps must be completed first</li>
+              <li>Wait for any pending transactions to confirm</li>
+            </ul>
+          `;
+          if (confirmBtn) {
+            confirmBtn.disabled = false;
+            confirmBtn.classList.remove('opacity-50', 'cursor-not-allowed');
+          }
+        }
       } else {
         title.textContent = `Switch ${displayName} to Full Node Mode`;
         message.textContent = 'Please confirm you want to switch to full node mode.';
+
+        try {
+          const response = await fetch('/json/modeswitchinfo', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ coin: coinName, direction: 'rpc' })
+          });
+          const info = await response.json();
+
+          let transferSection = '';
+          if (info.error) {
+            transferSection = `<p class="text-yellow-700 dark:text-yellow-300 text-sm">${info.error}</p>`;
+          } else if (info.balance_sats === 0) {
+            transferSection = `<p class="text-gray-600 dark:text-gray-300 text-sm">No funds to transfer.</p>`;
+          } else if (!info.can_transfer) {
+            transferSection = `
+              <p class="text-yellow-700 dark:text-yellow-300 text-sm">
+                Balance (${info.balance} ${info.coin}) is too low to transfer - fee would exceed funds.
+              </p>
+            `;
+          } else {
+            transferSection = `
+              <div class="bg-gray-200 dark:bg-gray-700 border border-gray-300 dark:border-gray-500 rounded-lg p-3 mb-3">
+                <p class="text-sm font-medium text-gray-900 dark:text-white mb-2">Fund Transfer Options</p>
+                <p class="text-xs text-gray-700 dark:text-gray-300 mb-3">
+                  Balance: ${info.balance} ${info.coin} | Est. fee: ${info.estimated_fee} ${info.coin}
+                </p>
+                <div class="space-y-2">
+                  <label class="flex items-start cursor-pointer hover:bg-gray-300 dark:hover:bg-gray-600 rounded p-1.5 -m-1">
+                    <input type="radio" name="transfer_choice" value="auto" class="mt-0.5 mr-2 h-4 w-4 text-blue-600 border-gray-400 dark:border-gray-400 focus:ring-blue-500 bg-white dark:bg-gray-500">
+                    <div>
+                      <span class="text-sm font-medium text-gray-900 dark:text-white">Auto-transfer funds to RPC wallet</span>
+                      <p class="text-xs text-gray-600 dark:text-gray-300">Recommended. Ensures all funds visible in full node wallet.</p>
+                    </div>
+                  </label>
+                  <label class="flex items-start cursor-pointer hover:bg-gray-300 dark:hover:bg-gray-600 rounded p-1.5 -m-1">
+                    <input type="radio" name="transfer_choice" value="manual" checked class="mt-0.5 mr-2 h-4 w-4 text-blue-600 border-gray-400 dark:border-gray-400 focus:ring-blue-500 bg-white dark:bg-gray-500">
+                    <div>
+                      <span class="text-sm font-medium text-gray-900 dark:text-white">Keep funds on current addresses</span>
+                      <p class="text-xs text-gray-600 dark:text-gray-300">Transfer manually later if needed.</p>
+                    </div>
+                  </label>
+                </div>
+                <p class="text-xs text-red-600 dark:text-red-400 mt-3">
+                  If you skip transfer, you will need to manually send funds from lite wallet addresses to your RPC wallet.
+                </p>
+              </div>
+            `;
+          }
+
           details.innerHTML = `
-          <p class="mb-2"><strong>Switching to full node mode:</strong></p>
+            <p class="mb-2 text-gray-800 dark:text-gray-100"><strong>Switching to full node mode:</strong></p>
-          <ul class="list-disc list-inside space-y-1">
+            <ul class="list-disc list-inside space-y-1 mb-3 text-gray-700 dark:text-gray-200">
               <li>Requires synced ${displayName} blockchain</li>
               <li>Your wallet addresses will be synced</li>
               <li>Active swaps must be completed first</li>
               <li>Restart required after switch</li>
             </ul>
-          <p class="mt-3 text-green-600 dark:text-green-400">
+            ${transferSection}
-            <strong>Note:</strong> Your balance will remain accessible - same seed means same funds in both modes.
-          </p>
           `;
-      }
 
-      modal.classList.remove('hidden');
+          if (confirmBtn) {
+            confirmBtn.disabled = false;
+            confirmBtn.classList.remove('opacity-50', 'cursor-not-allowed');
+          }
+        } catch (error) {
+          console.error('Failed to fetch mode switch info:', error);
+          details.innerHTML = `
+            <p class="mb-2 text-gray-800 dark:text-gray-100"><strong>Switching to full node mode:</strong></p>
+            <ul class="list-disc list-inside space-y-1 text-gray-700 dark:text-gray-200">
+              <li>Requires synced ${displayName} blockchain</li>
+              <li>Your wallet addresses will be synced</li>
+              <li>Active swaps must be completed first</li>
+              <li>Restart required after switch</li>
+            </ul>
+          `;
+          if (confirmBtn) {
+            confirmBtn.disabled = false;
+            confirmBtn.classList.remove('opacity-50', 'cursor-not-allowed');
+          }
+        }
+      }
     },
 
     hideWalletModeModal: function() {

basicswap/templates/wallet.html

@@ -82,6 +82,36 @@
 </section>
 {% endif %}
 
+{% if legacy_funds_info and legacy_funds_info.has_legacy_funds %}
+<section class="py-4 px-6" id="legacy_funds_warning">
+  <div class="lg:container mx-auto">
+    <div class="p-6 rounded-lg bg-yellow-50 border border-yellow-400 dark:bg-yellow-900/30 dark:border-yellow-700">
+      <div class="flex flex-wrap justify-between items-center -m-2">
+        <div class="flex-1 p-2">
+          <div class="flex flex-wrap -m-1">
+            <div class="w-auto p-1">
+              <svg class="w-6 h-6 text-yellow-600 dark:text-yellow-400" fill="currentColor" viewBox="0 0 20 20">
+                <path fill-rule="evenodd" d="M8.257 3.099c.765-1.36 2.722-1.36 3.486 0l5.58 9.92c.75 1.334-.213 2.98-1.742 2.98H4.42c-1.53 0-2.493-1.646-1.743-2.98l5.58-9.92zM11 13a1 1 0 11-2 0 1 1 0 012 0zm-1-8a1 1 0 00-1 1v3a1 1 0 002 0V6a1 1 0 00-1-1z" clip-rule="evenodd"/>
+              </svg>
+            </div>
+            <div class="ml-3 flex-1">
+              <p class="font-semibold text-lg lg:text-sm text-yellow-700 dark:text-yellow-300">Legacy Address Funds</p>
+              <p class="mt-1 text-sm text-yellow-600 dark:text-yellow-400">
+                {{ legacy_funds_info.legacy_balance }} {{ legacy_funds_info.coin }} on legacy addresses won't be visible in external Electrum wallet.
+                To use funds with external wallets, transfer to a new address.
+              </p>
+              <p class="mt-2 text-xs text-yellow-500 dark:text-yellow-500">
+                Use the withdraw function below to send funds to a new <code class="bg-yellow-100 dark:bg-yellow-800/50 px-1 rounded">{{ w.ticker | lower }}1...</code> address.
+              </p>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</section>
+{% endif %}
+
 <section>
     <form method="post" autocomplete="off">
       <div class="px-6 py-0 h-full overflow-hidden">

basicswap/ui/page_settings.py

@@ -180,11 +180,14 @@ def page_settings(self, url_split, post_string):
                                 form_data, "electrum_onion_" + name, ""
                             ).strip()
                             data["electrum_onion_servers"] = onion_servers
-                            auto_transfer = have_data_entry(
+                            auto_transfer_now = have_data_entry(
-                                form_data, "auto_transfer_" + name
+                                form_data, "auto_transfer_now_" + name
                             )
-                            data["auto_transfer_on_mode_switch"] = auto_transfer
+                            if auto_transfer_now:
-                            # Address gap limit for scanning
+                                transfer_value = get_data_entry_or(
+                                    form_data, "auto_transfer_now_" + name, "false"
+                                )
+                                data["auto_transfer_now"] = transfer_value == "true"
                             gap_limit_str = get_data_entry_or(
                                 form_data, "gap_limit_" + name, "20"
                             ).strip()
@@ -292,9 +295,6 @@ def page_settings(self, url_split, post_string):
                 "supports_electrum": name in electrum_supported_coins,
                 "clearnet_servers_text": clearnet_text,
                 "onion_servers_text": onion_text,
-                "auto_transfer_on_mode_switch": c.get(
-                    "auto_transfer_on_mode_switch", True
-                ),
                 "address_gap_limit": c.get("address_gap_limit", 20),
             }
         )

basicswap/ui/page_wallet.py

@@ -530,6 +530,7 @@ def page_wallet(self, url_split, post_string):
     transactions = []
     total_transactions = 0
     is_electrum_mode = False
+    legacy_funds_info = None
     if wallet_data.get("havedata", False) and not wallet_data.get("error"):
         try:
             ci = swap_client.ci(coin_id)
@@ -544,6 +545,9 @@ def page_wallet(self, url_split, post_string):
 
                 raw_txs = all_txs[skip : skip + count] if all_txs else []
                 transactions = format_transactions(ci, raw_txs, coin_id)
+            else:
+                if coin_id in (Coins.BTC, Coins.LTC):
+                    legacy_funds_info = swap_client.getElectrumLegacyFundsInfo(coin_id)
         except Exception as e:
             swap_client.log.warning(f"Failed to fetch transactions for {ticker}: {e}")
 
@@ -563,6 +567,7 @@ def page_wallet(self, url_split, post_string):
             "tx_total": total_transactions,
             "tx_limit": tx_filters.get("limit", 30),
             "is_electrum_mode": is_electrum_mode,
+            "legacy_funds_info": legacy_funds_info,
             "use_tor": getattr(swap_client, "use_tor_proxy", False),
         },
     )