upgrade to hwi 1.2.1

LICENSE (URKit)

@@ -1,19 +0,0 @@
-BSD-2-Clause Plus Patent License
-
-SPDX-License-Identifier: [BSD-2-Clause-Patent](https://spdx.org/licenses/BSD-2-Clause-Patent.html)
-
-Copyright © 2020 Blockchain Commons, LLC
-
-Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
-2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
-Subject to the terms and conditions of this license, each copyright holder and contributor hereby grants to those receiving rights under this license a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except for failure to satisfy the conditions of this license) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer this software, where such license applies only to those patent claims, already acquired or hereafter acquired, licensable by such copyright holder or contributor that are necessarily infringed by:
-
-(a) their Contribution(s) (the licensed copyrights of copyright holders and non-copyrightable additions of contributors, in source or binary form) alone; or
-(b) combination of their Contribution(s) with the work of authorship to which such Contribution(s) was added by such copyright holder or contributor, if, at the time the Contribution is added, such addition causes such combination to be necessarily infringed. The patent license shall not apply to any other combinations which include the Contribution.
-Except as expressly stated above, no rights or licenses from any copyright holder or contributor is granted under this license, whether expressly, by implication, estoppel or otherwise.
-
-DISCLAIMER
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -52,6 +52,8 @@ As a fallback, the network (mainnet, testnet or regtest) can also be set using a
 
 `export SPARROW_NETWORK=testnet`
 
+A final fallback which can be useful when running the Sparrow binary is to create a file called ``network-testnet`` in the Sparrow home folder (see below) to configure the testnet network.
+
 Note that if you are connecting to an Electrum server when using testnet, that server will need to running on testnet configuration as well.
 
 When not explicitly configured using the command line argument above, Sparrow stores it's mainnet config file, log file and wallets in a home folder location appropriate to the operating system:

build.gradle

@@ -5,7 +5,7 @@ plugins {
     id 'org.beryx.jlink' version '2.22.0'
 }
 
-def sparrowVersion = '0.9.5'
+def sparrowVersion = '0.9.8'
 def os = org.gradle.internal.os.OperatingSystem.current()
 def osName = os.getFamilyName()
 if(os.macOsX) {
@@ -20,6 +20,7 @@ repositories {
     maven { url 'https://oss.sonatype.org/content/groups/public' }
     maven { url 'https://mymavenrepo.com/repo/29EACwkkGcoOKnbx3bxN/' }
     maven { url 'https://jitpack.io' }
+    maven { url 'http://maven.openimaj.org/' }
 }
 
 tasks.withType(AbstractArchiveTask) {
@@ -50,8 +51,10 @@ dependencies {
     implementation('com.github.arteam:simple-json-rpc-server:1.0') {
         exclude group: 'org.slf4j'
     }
-    implementation('co.nstant.in:cbor:0.9')
-    implementation('com.nativelibs4java:bridj:0.7-20200803')
+    implementation('com.sparrowwallet:hummingbird:1.5.2')
+    implementation('com.nativelibs4java:bridj:0.7-20140918-3') {
+        exclude group: 'com.google.android.tools', module: 'dx'
+    }
     implementation('com.github.sarxos:webcam-capture:0.3.13-SNAPSHOT') {
         exclude group: 'com.nativelibs4java', module: 'bridj'
     }

src/main/deploy/package/osx/Info.plist

@@ -21,7 +21,7 @@
   <key>CFBundlePackageType</key>
   <string>APPL</string>
   <key>CFBundleShortVersionString</key>
-  <string>0.9.5</string>
+  <string>0.9.8</string>
   <key>CFBundleSignature</key>
   <string>????</string>
   <!-- See https://developer.apple.com/app-store/categories/ for list of AppStore categories -->

src/main/java/com/sparrowwallet/sparrow/AppController.java

@@ -7,6 +7,9 @@ import com.sparrowwallet.drongo.BitcoinUnit;
 import com.sparrowwallet.drongo.Network;
 import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.Utils;
+import com.sparrowwallet.drongo.address.Address;
+import com.sparrowwallet.drongo.crypto.ECKey;
+import com.sparrowwallet.drongo.crypto.EncryptionType;
 import com.sparrowwallet.drongo.crypto.InvalidPasswordException;
 import com.sparrowwallet.drongo.crypto.Key;
 import com.sparrowwallet.drongo.policy.PolicyType;
@@ -14,12 +17,16 @@ import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.protocol.Sha256Hash;
 import com.sparrowwallet.drongo.protocol.Transaction;
 import com.sparrowwallet.drongo.psbt.PSBT;
+import com.sparrowwallet.drongo.psbt.PSBTInput;
 import com.sparrowwallet.drongo.psbt.PSBTParseException;
+import com.sparrowwallet.drongo.uri.BitcoinURI;
 import com.sparrowwallet.drongo.wallet.*;
 import com.sparrowwallet.sparrow.control.*;
 import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.io.*;
 import com.sparrowwallet.sparrow.net.ElectrumServer;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
+import com.sparrowwallet.sparrow.net.MempoolRateSize;
 import com.sparrowwallet.sparrow.net.VersionCheckService;
 import com.sparrowwallet.sparrow.preferences.PreferencesDialog;
 import com.sparrowwallet.sparrow.transaction.TransactionController;
@@ -63,6 +70,9 @@ import java.io.*;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.text.ParseException;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.temporal.ChronoUnit;
 import java.util.*;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -70,7 +80,7 @@ import java.util.stream.Collectors;
 public class AppController implements Initializable {
     private static final Logger log = LoggerFactory.getLogger(AppController.class);
 
-    private static final int SERVER_PING_PERIOD = 10 * 1000;
+    private static final int SERVER_PING_PERIOD = 1 * 60 * 1000;
     private static final int ENUMERATE_HW_PERIOD = 30 * 1000;
     private static final int RATES_PERIOD = 5 * 60 * 1000;
     private static final int VERSION_CHECK_PERIOD_HOURS = 24;
@@ -138,12 +148,16 @@ public class AppController implements Initializable {
 
     private static Map<Integer, Double> targetBlockFeeRates;
 
+    private static final Map<Date, Set<MempoolRateSize>> mempoolHistogram = new TreeMap<>();
+
     private static Double minimumRelayFeeRate;
 
     private static CurrencyRate fiatCurrencyExchangeRate;
 
     private static List<Device> devices;
 
+    private static final Map<Address, BitcoinURI> payjoinURIs = new HashMap<>();
+
     @Override
     public void initialize(URL location, ResourceBundle resources) {
         EventManager.get().register(this);
@@ -445,7 +459,7 @@ public class AppController implements Initializable {
         FileChooser fileChooser = new FileChooser();
         fileChooser.setTitle("Open Transaction");
         fileChooser.getExtensionFilters().addAll(
-                new FileChooser.ExtensionFilter("All Files", "*.*"),
+                new FileChooser.ExtensionFilter("All Files", org.controlsfx.tools.Platform.getCurrent().equals(org.controlsfx.tools.Platform.UNIX) ? "*" : "*.*"),
                 new FileChooser.ExtensionFilter("PSBT", "*.psbt"),
                 new FileChooser.ExtensionFilter("TXN", "*.txn")
         );
@@ -559,17 +573,14 @@ public class AppController implements Initializable {
             if(result.transaction != null) {
                 Tab tab = addTransactionTab(null, result.transaction);
                 tabs.getSelectionModel().select(tab);
-            }
-            if(result.psbt != null) {
+            } else if(result.psbt != null) {
                 Tab tab = addTransactionTab(null, result.psbt);
                 tabs.getSelectionModel().select(tab);
-            }
-            if(result.error != null) {
-                showErrorDialog("Invalid QR Code", result.error);
-            }
-            if(result.exception != null) {
-                log.error("Error opening webcam", result.exception);
-                showErrorDialog("Error opening webcam", result.exception.getMessage());
+            } else if(result.exception != null) {
+                log.error("Error scanning QR", result.exception);
+                showErrorDialog("Error scanning QR", result.exception.getMessage());
+            } else {
+                AppController.showErrorDialog("Invalid QR Code", "Cannot parse QR code into a transaction or PSBT");
             }
         }
     }
@@ -646,8 +657,21 @@ public class AppController implements Initializable {
         return targetBlockFeeRates;
     }
 
+    public static Map<Date, Set<MempoolRateSize>> getMempoolHistogram() {
+        return mempoolHistogram;
+    }
+
+    private void addMempoolRateSizes(Set<MempoolRateSize> rateSizes) {
+        LocalDateTime dateMinute = LocalDateTime.now().truncatedTo(ChronoUnit.MINUTES);
+        if(mempoolHistogram.isEmpty()) {
+            mempoolHistogram.put(Date.from(dateMinute.minusMinutes(1).atZone(ZoneId.systemDefault()).toInstant()), rateSizes);
+        }
+
+        mempoolHistogram.put(Date.from(dateMinute.atZone(ZoneId.systemDefault()).toInstant()), rateSizes);
+    }
+
     public static Double getMinimumRelayFeeRate() {
-        return minimumRelayFeeRate;
+        return minimumRelayFeeRate == null ? Transaction.DEFAULT_MIN_RELAY_FEE : minimumRelayFeeRate;
     }
 
     public static CurrencyRate getFiatCurrencyExchangeRate() {
@@ -658,6 +682,17 @@ public class AppController implements Initializable {
         return devices == null ? new ArrayList<>() : devices;
     }
 
+    public static BitcoinURI getPayjoinURI(Address address) {
+        return payjoinURIs.get(address);
+    }
+
+    public static void addPayjoinURI(BitcoinURI bitcoinURI) {
+        if(bitcoinURI.getPayjoinUrl() == null) {
+            throw new IllegalArgumentException("Not a payjoin URI");
+        }
+        payjoinURIs.put(bitcoinURI.getAddress(), bitcoinURI);
+    }
+
     public Map<Wallet, Storage> getOpenWallets() {
         Map<Wallet, Storage> openWallets = new LinkedHashMap<>();
 
@@ -911,13 +946,13 @@ public class AppController implements Initializable {
     }
 
     private void addImportedWallet(Wallet wallet) {
-        File walletFile = Storage.getWalletFile(wallet.getName());
+        File walletFile = Storage.getExistingWallet(wallet.getName());
 
-        if(walletFile.exists()) {
+        if(walletFile != null) {
             Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
             alert.setTitle("Existing wallet found");
             alert.setHeaderText("Replace existing wallet?");
-            alert.setContentText("Wallet file " + wallet.getName() + " already exists");
+            alert.setContentText("Wallet file " + walletFile.getName() + " already exists.\n");
             Optional<ButtonType> result = alert.showAndWait();
             if(result.isPresent() && result.get() == ButtonType.CANCEL) {
                 return;
@@ -934,11 +969,47 @@ public class AppController implements Initializable {
                     }
                 }
             }
+
+            walletFile.delete();
         }
 
-        Storage storage = new Storage(walletFile);
-        Tab tab = addWalletTab(storage, wallet);
-        tabs.getSelectionModel().select(tab);
+        Storage storage = new Storage(Storage.getWalletFile(wallet.getName()));
+        WalletPasswordDialog dlg = new WalletPasswordDialog(WalletPasswordDialog.PasswordRequirement.UPDATE_NEW);
+        Optional<SecureString> password = dlg.showAndWait();
+        if(password.isPresent()) {
+            if(password.get().length() == 0) {
+                storage.setEncryptionPubKey(Storage.NO_PASSWORD_KEY);
+                Tab tab = addWalletTab(storage, wallet);
+                tabs.getSelectionModel().select(tab);
+            } else {
+                Storage.KeyDerivationService keyDerivationService = new Storage.KeyDerivationService(storage, password.get());
+                keyDerivationService.setOnSucceeded(workerStateEvent -> {
+                    EventManager.get().post(new StorageEvent(Storage.getWalletFile(wallet.getName()), TimedEvent.Action.END, "Done"));
+                    ECKey encryptionFullKey = keyDerivationService.getValue();
+                    Key key = null;
+
+                    try {
+                        ECKey encryptionPubKey = ECKey.fromPublicOnly(encryptionFullKey);
+                        key = new Key(encryptionFullKey.getPrivKeyBytes(), storage.getKeyDeriver().getSalt(), EncryptionType.Deriver.ARGON2);
+                        wallet.encrypt(key);
+                        storage.setEncryptionPubKey(encryptionPubKey);
+                        Tab tab = addWalletTab(storage, wallet);
+                        tabs.getSelectionModel().select(tab);
+                    } finally {
+                        encryptionFullKey.clear();
+                        if(key != null) {
+                            key.clear();
+                        }
+                    }
+                });
+                keyDerivationService.setOnFailed(workerStateEvent -> {
+                    EventManager.get().post(new StorageEvent(Storage.getWalletFile(wallet.getName()), TimedEvent.Action.END, "Failed"));
+                    showErrorDialog("Error encrypting wallet", keyDerivationService.getException().getMessage());
+                });
+                EventManager.get().post(new StorageEvent(Storage.getWalletFile(wallet.getName()), TimedEvent.Action.START, "Encrypting wallet..."));
+                keyDerivationService.start();
+            }
+        }
     }
 
     public void exportWallet(ActionEvent event) {
@@ -996,6 +1067,9 @@ public class AppController implements Initializable {
             if(name.endsWith(".json")) {
                 name = name.substring(0, name.lastIndexOf('.'));
             }
+            if(!name.equals(wallet.getName())) {
+                wallet.setName(name);
+            }
             Tab tab = new Tab(name);
             tab.setContextMenu(getTabContextMenu(tab));
             tab.setClosable(true);
@@ -1084,14 +1158,31 @@ public class AppController implements Initializable {
 
                 //If an exact match bytewise of an existing tab, return that tab
                 if(Arrays.equals(transactionTabData.getTransaction().bitcoinSerialize(), transaction.bitcoinSerialize())) {
-                    //As per BIP174, combine PSBTs with matching transactions so long as they are not yet finalized
-                    if(transactionTabData.getPsbt() != null && psbt != null && !transactionTabData.getPsbt().isFinalized() && !psbt.isFinalized()) {
-                        transactionTabData.getPsbt().combine(psbt);
-                        if(name != null && !name.isEmpty()) {
-                            tab.setText(name);
-                        }
+                    if(transactionTabData.getPsbt() != null && psbt != null && !transactionTabData.getPsbt().isFinalized()) {
+                        if(!psbt.isFinalized()) {
+                            //As per BIP174, combine PSBTs with matching transactions so long as they are not yet finalized
+                            transactionTabData.getPsbt().combine(psbt);
+                            if(name != null && !name.isEmpty()) {
+                                tab.setText(name);
+                            }
 
-                        EventManager.get().post(new PSBTCombinedEvent(transactionTabData.getPsbt()));
+                            EventManager.get().post(new PSBTCombinedEvent(transactionTabData.getPsbt()));
+                        } else {
+                            //If the new PSBT is finalized, copy the finalized fields to the existing unfinalized PSBT
+                            for(int i = 0; i < transactionTabData.getPsbt().getPsbtInputs().size(); i++) {
+                                PSBTInput existingInput = transactionTabData.getPsbt().getPsbtInputs().get(i);
+                                PSBTInput finalizedInput = psbt.getPsbtInputs().get(i);
+                                existingInput.setFinalScriptSig(finalizedInput.getFinalScriptSig());
+                                existingInput.setFinalScriptWitness(finalizedInput.getFinalScriptWitness());
+                                existingInput.clearNonFinalFields();
+                            }
+
+                            if(name != null && !name.isEmpty()) {
+                                tab.setText(name);
+                            }
+
+                            EventManager.get().post(new PSBTFinalizedEvent(transactionTabData.getPsbt()));
+                        }
                     }
 
                     return tab;
@@ -1358,6 +1449,7 @@ public class AppController implements Initializable {
     public void newConnection(ConnectionEvent event) {
         currentBlockHeight = event.getBlockHeight();
         targetBlockFeeRates = event.getTargetBlockFeeRates();
+        addMempoolRateSizes(event.getMempoolRateSizes());
         minimumRelayFeeRate = event.getMinimumRelayFeeRate();
         String banner = event.getServerBanner();
         String status = "Connected to " + Config.get().getElectrumServer() + " at height " + event.getBlockHeight();
@@ -1382,6 +1474,7 @@ public class AppController implements Initializable {
     @Subscribe
     public void feesUpdated(FeeRatesUpdatedEvent event) {
         targetBlockFeeRates = event.getTargetBlockFeeRates();
+        addMempoolRateSizes(event.getMempoolRateSizes());
     }
 
     @Subscribe
@@ -1402,6 +1495,15 @@ public class AppController implements Initializable {
         selectedToggle.ifPresent(toggle -> bitcoinUnit.selectToggle(toggle));
     }
 
+    @Subscribe
+    public void feeRateSourceChanged(FeeRatesSourceChangedEvent event) {
+        ElectrumServer.FeeRatesService feeRatesService = new ElectrumServer.FeeRatesService();
+        feeRatesService.setOnSucceeded(workerStateEvent -> {
+            EventManager.get().post(feeRatesService.getValue());
+        });
+        feeRatesService.start();
+    }
+
     @Subscribe
     public void fiatCurrencySelected(FiatCurrencySelectedEvent event) {
         ratesService.cancel();

src/main/java/com/sparrowwallet/sparrow/MainApp.java

@@ -8,6 +8,7 @@ import com.sparrowwallet.sparrow.glyphfont.FontAwesome5Brands;
 import com.sparrowwallet.sparrow.io.Config;
 import com.sparrowwallet.sparrow.io.FileType;
 import com.sparrowwallet.sparrow.io.IOUtils;
+import com.sparrowwallet.sparrow.io.Storage;
 import com.sparrowwallet.sparrow.preferences.PreferenceGroup;
 import com.sparrowwallet.sparrow.preferences.PreferencesDialog;
 import javafx.application.Application;
@@ -30,7 +31,7 @@ public class MainApp extends Application {
     private static final Logger log = LoggerFactory.getLogger(MainApp.class);
 
     public static final String APP_NAME = "Sparrow";
-    public static final String APP_VERSION = "0.9.5";
+    public static final String APP_VERSION = "0.9.8";
     public static final String APP_HOME_PROPERTY = "sparrow.home";
     public static final String NETWORK_ENV_PROPERTY = "SPARROW_NETWORK";
 
@@ -77,7 +78,7 @@ public class MainApp extends Application {
 
         stage.setTitle("Sparrow");
         stage.setMinWidth(650);
-        stage.setMinHeight(700);
+        stage.setMinHeight(830);
         stage.setScene(scene);
         stage.getIcons().add(new Image(MainApp.class.getResourceAsStream("/image/sparrow.png")));
 
@@ -138,6 +139,11 @@ public class MainApp extends Application {
             }
         }
 
+        File testnetFlag = new File(Storage.getSparrowHome(), "network-" + Network.TESTNET.getName());
+        if(testnetFlag.exists()) {
+            Network.set(Network.TESTNET);
+        }
+
         if(Network.get() != Network.MAINNET) {
             log.info("Using " + Network.get() + " configuration");
         }

src/main/java/com/sparrowwallet/sparrow/control/AddressCell.java

@@ -58,7 +58,7 @@ public class AddressCell extends TreeTableCell<Entry, Entry> {
     }
 
     private String getTooltipText(UtxoEntry utxoEntry) {
-        return utxoEntry.getNode().getDerivationPath() + (utxoEntry.isDuplicateAddress() ? " (Duplicate address)" : "");
+        return utxoEntry.getNode().getDerivationPath().replace("m", "..") + (utxoEntry.isDuplicateAddress() ? " (Duplicate address)" : "");
     }
 
     public static Glyph getDuplicateGlyph() {

src/main/java/com/sparrowwallet/sparrow/control/BlockTargetFeeRatesChart.java

@@ -9,11 +9,11 @@ import javafx.scene.chart.XYChart;
 import java.util.Iterator;
 import java.util.Map;
 
-public class FeeRatesChart extends LineChart<String, Number> {
+public class BlockTargetFeeRatesChart extends LineChart<String, Number> {
     private XYChart.Series<String, Number> feeRateSeries;
     private Integer selectedTargetBlocks;
 
-    public FeeRatesChart(@NamedArg("xAxis") Axis<String> xAxis, @NamedArg("yAxis") Axis<Number> yAxis) {
+    public BlockTargetFeeRatesChart(@NamedArg("xAxis") Axis<String> xAxis, @NamedArg("yAxis") Axis<Number> yAxis) {
         super(xAxis, yAxis);
     }
 

src/main/java/com/sparrowwallet/sparrow/control/CoinTreeTable.java

@@ -38,18 +38,23 @@ public class CoinTreeTable extends TreeTableView<Entry> {
     }
 
     public void updateHistoryStatus(WalletHistoryStatusEvent event) {
-        Platform.runLater(() -> {
-            if(event.getErrorMessage() != null) {
-                setPlaceholder(new Label("Error loading transactions: " + event.getErrorMessage()));
-            } else if(event.isLoading()) {
-                if(event.getStatusMessage() != null) {
-                    setPlaceholder(new Label(event.getStatusMessage() + "..."));
-                } else {
-                    setPlaceholder(new Label("Loading transactions..."));
-                }
-            } else {
-                setPlaceholder(new Label("No transactions"));
+        if(getRoot() != null) {
+            Entry entry = getRoot().getValue();
+            if(entry != null && event.getWallet() != null && entry.getWallet() == event.getWallet()) {
+                Platform.runLater(() -> {
+                    if(event.getErrorMessage() != null) {
+                        setPlaceholder(new Label("Error loading transactions: " + event.getErrorMessage()));
+                    } else if(event.isLoading()) {
+                        if(event.getStatusMessage() != null) {
+                            setPlaceholder(new Label(event.getStatusMessage() + "..."));
+                        } else {
+                            setPlaceholder(new Label("Loading transactions..."));
+                        }
+                    } else {
+                        setPlaceholder(new Label("No transactions"));
+                    }
+                });
             }
-        });
+        }
     }
 }

src/main/java/com/sparrowwallet/sparrow/control/DevicePane.java

@@ -3,6 +3,7 @@ package com.sparrowwallet.sparrow.control;
 import com.sparrowwallet.drongo.ExtendedKey;
 import com.sparrowwallet.drongo.KeyDerivation;
 import com.sparrowwallet.drongo.crypto.ChildNumber;
+import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.wallet.Keystore;
 import com.sparrowwallet.drongo.wallet.KeystoreSource;
@@ -31,10 +32,14 @@ import org.controlsfx.validation.ValidationResult;
 import org.controlsfx.validation.ValidationSupport;
 import org.controlsfx.validation.Validator;
 import org.controlsfx.validation.decoration.StyleClassValidationDecoration;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.List;
 
 public class DevicePane extends TitledDescriptionPane {
+    private static final Logger log = LoggerFactory.getLogger(DevicePane.class);
+
     private final DeviceOperation deviceOperation;
     private final Wallet wallet;
     private final PSBT psbt;
@@ -68,7 +73,12 @@ public class DevicePane extends TitledDescriptionPane {
         createSetPassphraseButton();
         createImportButton();
 
-        if (device.getNeedsPinSent() != null && device.getNeedsPinSent()) {
+        if(device.getError() != null) {
+            setError("Error", device.getError());
+            Platform.runLater(() -> {
+                setExpanded(true);
+            });
+        } else if(device.getNeedsPinSent() != null && device.getNeedsPinSent()) {
             unlockButton.setVisible(true);
         } else if(device.getNeedsPassphraseSent() != null && device.getNeedsPassphraseSent()) {
             setPassphraseButton.setVisible(true);
@@ -199,7 +209,8 @@ public class DevicePane extends TitledDescriptionPane {
             importKeystore(wallet.getScriptType().getDefaultDerivation());
         });
         String[] accounts = new String[] {"Default Account #0", "Account #1", "Account #2", "Account #3", "Account #4", "Account #5", "Account #6", "Account #7", "Account #8", "Account #9"};
-        for(int i = 0; i < accounts.length; i++) {
+        int scriptAccountsLength = ScriptType.P2SH.equals(wallet.getScriptType()) ? 1 : accounts.length;
+        for(int i = 0; i < scriptAccountsLength; i++) {
             MenuItem item = new MenuItem(accounts[i]);
             final List<ChildNumber> derivation = wallet.getScriptType().getDefaultDerivation(i);
             item.setOnAction(event -> {
@@ -465,6 +476,7 @@ public class DevicePane extends TitledDescriptionPane {
         });
         signPSBTService.setOnFailed(workerStateEvent -> {
             setError("Signing Error", signPSBTService.getException().getMessage());
+            log.error("Signing Error: " + signPSBTService.getException().getMessage());
             signButton.setDisable(false);
         });
         setDescription("Signing...");

src/main/java/com/sparrowwallet/sparrow/control/EntryCell.java

@@ -2,8 +2,11 @@ package com.sparrowwallet.sparrow.control;
 
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.address.Address;
-import com.sparrowwallet.drongo.wallet.BlockTransaction;
-import com.sparrowwallet.drongo.wallet.KeystoreSource;
+import com.sparrowwallet.drongo.protocol.NonStandardScriptException;
+import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.protocol.TransactionOutput;
+import com.sparrowwallet.drongo.wallet.*;
+import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.glyphfont.FontAwesome5;
@@ -19,7 +22,7 @@ import org.controlsfx.glyphfont.Glyph;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
-import java.util.List;
+import java.util.*;
 import java.util.stream.Collectors;
 
 class EntryCell extends TreeTableCell<Entry, Entry> {
@@ -46,10 +49,10 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
                 TransactionEntry transactionEntry = (TransactionEntry)entry;
                 if(transactionEntry.getBlockTransaction().getHeight() == -1) {
                     setText("Unconfirmed Parent");
-                    setContextMenu(new UnconfirmedTransactionContextMenu(transactionEntry.getBlockTransaction()));
+                    setContextMenu(new UnconfirmedTransactionContextMenu(transactionEntry));
                 } else if(transactionEntry.getBlockTransaction().getHeight() == 0) {
                     setText("Unconfirmed");
-                    setContextMenu(new UnconfirmedTransactionContextMenu(transactionEntry.getBlockTransaction()));
+                    setContextMenu(new UnconfirmedTransactionContextMenu(transactionEntry));
                 } else {
                     String date = DATE_FORMAT.format(transactionEntry.getBlockTransaction().getDate());
                     setText(date);
@@ -60,6 +63,7 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
                 tooltip.setText(transactionEntry.getBlockTransaction().getHash().toString());
                 setTooltip(tooltip);
 
+                HBox actionBox = new HBox();
                 Button viewTransactionButton = new Button("");
                 Glyph searchGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.SEARCH);
                 searchGlyph.setFontSize(12);
@@ -67,14 +71,28 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
                 viewTransactionButton.setOnAction(event -> {
                     EventManager.get().post(new ViewTransactionEvent(transactionEntry.getBlockTransaction()));
                 });
-                setGraphic(viewTransactionButton);
+                actionBox.getChildren().add(viewTransactionButton);
+
+                BlockTransaction blockTransaction = transactionEntry.getBlockTransaction();
+                if(blockTransaction.getHeight() <= 0 && blockTransaction.getTransaction().isReplaceByFee() && transactionEntry.getWallet().allInputsFromWallet(blockTransaction.getHash())) {
+                    Button increaseFeeButton = new Button("");
+                    Glyph increaseFeeGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.HAND_HOLDING_MEDICAL);
+                    increaseFeeGlyph.setFontSize(12);
+                    increaseFeeButton.setGraphic(increaseFeeGlyph);
+                    increaseFeeButton.setOnAction(event -> {
+                        increaseFee(transactionEntry);
+                    });
+                    actionBox.getChildren().add(increaseFeeButton);
+                }
+
+                setGraphic(actionBox);
             } else if(entry instanceof NodeEntry) {
                 NodeEntry nodeEntry = (NodeEntry)entry;
                 Address address = nodeEntry.getAddress();
                 setText(address.toString());
                 setContextMenu(new AddressContextMenu(address, nodeEntry.getOutputDescriptor(), null));
                 Tooltip tooltip = new Tooltip();
-                tooltip.setText(nodeEntry.getNode().getDerivationPath());
+                tooltip.setText(nodeEntry.getNode().getDerivationPath().replace("m", ".."));
                 setTooltip(tooltip);
                 getStyleClass().add("address-cell");
 
@@ -139,9 +157,9 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
                             utxoEntries = List.of(hashIndexEntry);
                         }
 
-                        final List<HashIndexEntry> spendingUtxoEntries = utxoEntries;
-                        EventManager.get().post(new SendActionEvent(utxoEntries));
-                        Platform.runLater(() -> EventManager.get().post(new SpendUtxoEvent(spendingUtxoEntries)));
+                        final List<BlockTransactionHashIndex> spendingUtxos = utxoEntries.stream().map(HashIndexEntry::getHashIndex).collect(Collectors.toList());
+                        EventManager.get().post(new SendActionEvent(hashIndexEntry.getWallet(), spendingUtxos));
+                        Platform.runLater(() -> EventManager.get().post(new SpendUtxoEvent(hashIndexEntry.getWallet(), spendingUtxos)));
                     });
                     actionBox.getChildren().add(spendUtxoButton);
                 }
@@ -151,8 +169,63 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
         }
     }
 
+    private static void increaseFee(TransactionEntry transactionEntry) {
+        BlockTransaction blockTransaction = transactionEntry.getBlockTransaction();
+        Map<BlockTransactionHashIndex, WalletNode> walletTxos = transactionEntry.getWallet().getWalletTxos();
+        List<BlockTransactionHashIndex> utxos = transactionEntry.getChildren().stream()
+                .filter(e -> e instanceof HashIndexEntry)
+                .map(e -> (HashIndexEntry)e)
+                .filter(e -> e.getType().equals(HashIndexEntry.Type.INPUT) && e.isSpendable())
+                .map(e -> blockTransaction.getTransaction().getInputs().get((int)e.getHashIndex().getIndex()))
+                .map(txInput -> walletTxos.keySet().stream().filter(txo -> txo.getHash().equals(txInput.getOutpoint().getHash()) && txo.getIndex() == txInput.getOutpoint().getIndex()).findFirst().get())
+                .collect(Collectors.toList());
+
+        List<TransactionOutput> ourOutputs = transactionEntry.getChildren().stream()
+                .filter(e -> e instanceof HashIndexEntry)
+                .map(e -> (HashIndexEntry)e)
+                .filter(e -> e.getType().equals(HashIndexEntry.Type.OUTPUT))
+                .map(e -> e.getBlockTransaction().getTransaction().getOutputs().get((int)e.getHashIndex().getIndex()))
+                .collect(Collectors.toList());
+
+        long changeTotal = ourOutputs.stream().mapToLong(TransactionOutput::getValue).sum();
+        Transaction tx = blockTransaction.getTransaction();
+        int vSize = tx.getVirtualSize();
+        int inputSize = tx.getInputs().get(0).getLength() + (tx.getInputs().get(0).hasWitness() ? tx.getInputs().get(0).getWitness().getLength() / Transaction.WITNESS_SCALE_FACTOR : 0);
+        List<BlockTransactionHashIndex> walletUtxos = new ArrayList<>(transactionEntry.getWallet().getWalletUtxos().keySet());
+        Collections.shuffle(walletUtxos);
+        while((double)changeTotal / vSize < getMaxFeeRate() && !walletUtxos.isEmpty()) {
+            //If there is insufficent change output, include another random UTXO so the fee can be increased
+            BlockTransactionHashIndex utxo = walletUtxos.remove(0);
+            utxos.add(utxo);
+            changeTotal += utxo.getValue();
+            vSize += inputSize;
+        }
+
+        List<TransactionOutput> externalOutputs = new ArrayList<>(blockTransaction.getTransaction().getOutputs());
+        externalOutputs.removeAll(ourOutputs);
+        List<Payment> payments = externalOutputs.stream().map(txOutput -> {
+            try {
+                return new Payment(txOutput.getScript().getToAddresses()[0], transactionEntry.getLabel(), txOutput.getValue(), false);
+            } catch(Exception e) {
+                return null;
+            }
+        }).filter(Objects::nonNull).collect(Collectors.toList());
+
+        EventManager.get().post(new SendActionEvent(transactionEntry.getWallet(), utxos));
+        Platform.runLater(() -> EventManager.get().post(new SpendUtxoEvent(transactionEntry.getWallet(), utxos, payments, blockTransaction.getFee(), true)));
+    }
+
+    private static Double getMaxFeeRate() {
+        if(AppController.getTargetBlockFeeRates().isEmpty()) {
+            return 100.0;
+        }
+
+        return AppController.getTargetBlockFeeRates().values().iterator().next();
+    }
+
     private static class UnconfirmedTransactionContextMenu extends ContextMenu {
-        public UnconfirmedTransactionContextMenu(BlockTransaction blockTransaction) {
+        public UnconfirmedTransactionContextMenu(TransactionEntry transactionEntry) {
+            BlockTransaction blockTransaction = transactionEntry.getBlockTransaction();
             MenuItem copyTxid = new MenuItem("Copy Transaction ID");
             copyTxid.setOnAction(AE -> {
                 hide();
@@ -161,7 +234,17 @@ class EntryCell extends TreeTableCell<Entry, Entry> {
                 Clipboard.getSystemClipboard().setContent(content);
             });
 
-            getItems().addAll(copyTxid);
+            getItems().add(copyTxid);
+
+            if(blockTransaction.getTransaction().isReplaceByFee() && transactionEntry.getWallet().allInputsFromWallet(blockTransaction.getHash())) {
+                MenuItem increaseFee = new MenuItem("Increase Fee");
+                increaseFee.setOnAction(AE -> {
+                    hide();
+                    increaseFee(transactionEntry);
+                });
+
+                getItems().add(increaseFee);
+            }
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/control/FileImportPane.java

@@ -2,6 +2,10 @@ package com.sparrowwallet.sparrow.control;
 
 import com.google.gson.JsonParseException;
 import com.sparrowwallet.drongo.crypto.InvalidPasswordException;
+import com.sparrowwallet.drongo.protocol.ScriptType;
+import com.sparrowwallet.drongo.wallet.Keystore;
+import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.sparrow.glyphfont.FontAwesome5;
 import com.sparrowwallet.sparrow.io.FileImport;
 import com.sparrowwallet.sparrow.io.ImportException;
 import javafx.beans.property.SimpleStringProperty;
@@ -9,41 +13,75 @@ import javafx.geometry.Insets;
 import javafx.geometry.Pos;
 import javafx.scene.Node;
 import javafx.scene.control.Button;
+import javafx.scene.control.ButtonBase;
 import javafx.scene.control.Control;
+import javafx.scene.control.ToggleButton;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.Priority;
 import javafx.stage.FileChooser;
 import javafx.stage.Stage;
+import org.controlsfx.control.SegmentedButton;
 import org.controlsfx.control.textfield.CustomPasswordField;
 import org.controlsfx.control.textfield.TextFields;
+import org.controlsfx.glyphfont.Glyph;
+import org.controlsfx.tools.Platform;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.BufferedInputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.InputStream;
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Optional;
 
 public abstract class FileImportPane extends TitledDescriptionPane {
     private static final Logger log = LoggerFactory.getLogger(FileImportPane.class);
 
     private final FileImport importer;
-    protected Button importButton;
+    protected ButtonBase importButton;
     private final SimpleStringProperty password = new SimpleStringProperty("");
+    private final boolean scannable;
+    protected List<Wallet> wallets;
 
-    public FileImportPane(FileImport importer, String title, String description, String content, String imageUrl) {
+    public FileImportPane(FileImport importer, String title, String description, String content, String imageUrl, boolean scannable) {
         super(title, description, content, imageUrl);
         this.importer = importer;
+        this.scannable = scannable;
+
+        buttonBox.getChildren().clear();
+        buttonBox.getChildren().add(createButton());
     }
 
     @Override
     protected Control createButton() {
-        importButton = new Button("Import File...");
-        importButton.setAlignment(Pos.CENTER_RIGHT);
-        importButton.setOnAction(event -> {
-            importFile();
-        });
-        return importButton;
+        if(scannable) {
+            ToggleButton scanButton = new ToggleButton("Scan...");
+            Glyph cameraGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.CAMERA);
+            cameraGlyph.setFontSize(12);
+            scanButton.setGraphic(cameraGlyph);
+            scanButton.setOnAction(event -> {
+                scanButton.setSelected(false);
+                importQR();
+            });
+
+            ToggleButton fileButton = new ToggleButton("Import File...");
+            fileButton.setAlignment(Pos.CENTER_RIGHT);
+            fileButton.setOnAction(event -> {
+                fileButton.setSelected(false);
+                importFile();
+            });
+            importButton = fileButton;
+
+            SegmentedButton segmentedButton = new SegmentedButton();
+            segmentedButton.getButtons().addAll(scanButton, fileButton);
+            return segmentedButton;
+        } else {
+            importButton = new Button("Import File...");
+            importButton.setAlignment(Pos.CENTER_RIGHT);
+            importButton.setOnAction(event -> {
+                importFile();
+            });
+            return importButton;
+        }
     }
 
     private void importFile() {
@@ -52,7 +90,7 @@ public abstract class FileImportPane extends TitledDescriptionPane {
         FileChooser fileChooser = new FileChooser();
         fileChooser.setTitle("Open " + importer.getWalletModel().toDisplayString() + " File");
         fileChooser.getExtensionFilters().addAll(
-                new FileChooser.ExtensionFilter("All Files", "*.*"),
+                new FileChooser.ExtensionFilter("All Files", Platform.getCurrent().equals(Platform.UNIX) ? "*" : "*.*"),
                 new FileChooser.ExtensionFilter("JSON", "*.json"),
                 new FileChooser.ExtensionFilter("TXT", "*.txt")
         );
@@ -94,6 +132,53 @@ public abstract class FileImportPane extends TitledDescriptionPane {
         }
     }
 
+    private void importQR() {
+        QRScanDialog qrScanDialog = new QRScanDialog();
+        Optional<QRScanDialog.Result> optionalResult = qrScanDialog.showAndWait();
+        if(optionalResult.isPresent()) {
+            QRScanDialog.Result result = optionalResult.get();
+            if(result.wallets != null) {
+                wallets = result.wallets;
+                try {
+                    importFile(importer.getName(), null, null);
+                } catch(ImportException e) {
+                    setError("Import Error", e.getMessage());
+                }
+            } else if(result.payload != null) {
+                try {
+                    importFile(importer.getName(), new ByteArrayInputStream(result.payload.getBytes(StandardCharsets.UTF_8)), null);
+                } catch(Exception e) {
+                    log.error("Error importing QR", e);
+                    String errorMessage = e.getMessage();
+                    if(e.getCause() != null && e.getCause().getMessage() != null && !e.getCause().getMessage().isEmpty()) {
+                        errorMessage = e.getCause().getMessage();
+                    }
+                    if(e instanceof JsonParseException || e.getCause() instanceof JsonParseException) {
+                        errorMessage = "QR contents were not in JSON format";
+                    }
+                    setError("Import Error", errorMessage);
+                }
+            } else if(result.exception != null) {
+                log.error("Error importing QR", result.exception);
+                setError("Import Error", result.exception.getMessage());
+            }
+        }
+    }
+
+    protected Keystore getScannedKeystore(ScriptType scriptType) throws ImportException {
+        if(wallets != null) {
+            for(Wallet wallet : wallets) {
+                if(scriptType.equals(wallet.getScriptType()) && !wallet.getKeystores().isEmpty()) {
+                    return wallet.getKeystores().get(0);
+                }
+            }
+
+            throw new ImportException("Script type " + scriptType + " is not supported");
+        }
+
+        return null;
+    }
+
     protected abstract void importFile(String fileName, InputStream inputStream, String password) throws ImportException;
 
     private Node getPasswordEntry(File file) {
@@ -103,6 +188,7 @@ public abstract class FileImportPane extends TitledDescriptionPane {
         HBox.setHgrow(passwordField, Priority.ALWAYS);
 
         Button importEncryptedButton = new Button("Import");
+        importEncryptedButton.setDefaultButton(true);
         importEncryptedButton.setOnAction(event -> {
             showHideLink.setVisible(true);
             setExpanded(false);

src/main/java/com/sparrowwallet/sparrow/control/FileKeystoreImportPane.java

@@ -14,13 +14,17 @@ public class FileKeystoreImportPane extends FileImportPane {
     private final KeystoreFileImport importer;
 
     public FileKeystoreImportPane(Wallet wallet, KeystoreFileImport importer) {
-        super(importer, importer.getName(), "Keystore file import", importer.getKeystoreImportDescription(), "image/" + importer.getWalletModel().getType() + ".png");
+        super(importer, importer.getName(), "Keystore import", importer.getKeystoreImportDescription(), "image/" + importer.getWalletModel().getType() + ".png", importer.isKeystoreImportScannable());
         this.wallet = wallet;
         this.importer = importer;
     }
 
     protected void importFile(String fileName, InputStream inputStream, String password) throws ImportException {
-        Keystore keystore = importer.getKeystore(wallet.getScriptType(), inputStream, password);
+        Keystore keystore = getScannedKeystore(wallet.getScriptType());
+        if(keystore == null) {
+            keystore = importer.getKeystore(wallet.getScriptType(), inputStream, password);
+        }
+
         EventManager.get().post(new KeystoreImportEvent(keystore));
     }
 }

src/main/java/com/sparrowwallet/sparrow/control/FileWalletImportPane.java

@@ -12,7 +12,7 @@ public class FileWalletImportPane extends FileImportPane {
     private final WalletImport importer;
 
     public FileWalletImportPane(WalletImport importer) {
-        super(importer, importer.getName(), "Wallet file import", importer.getWalletImportDescription(), "image/" + importer.getWalletModel().getType() + ".png");
+        super(importer, importer.getName(), "Wallet import", importer.getWalletImportDescription(), "image/" + importer.getWalletModel().getType() + ".png", importer.isWalletImportScannable());
         this.importer = importer;
     }
 

src/main/java/com/sparrowwallet/sparrow/control/FileWalletKeystoreImportPane.java

@@ -36,7 +36,7 @@ public class FileWalletKeystoreImportPane extends FileImportPane {
     private byte[] fileBytes;
 
     public FileWalletKeystoreImportPane(KeystoreFileImport importer) {
-        super(importer, importer.getName(), "Wallet file import", importer.getKeystoreImportDescription(), "image/" + importer.getWalletModel().getType() + ".png");
+        super(importer, importer.getName(), "Wallet import", importer.getKeystoreImportDescription(), "image/" + importer.getWalletModel().getType() + ".png", importer.isKeystoreImportScannable());
         this.importer = importer;
     }
 

src/main/java/com/sparrowwallet/sparrow/control/MempoolSizeFeeRatesChart.java

@@ -0,0 +1,188 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.sparrowwallet.sparrow.glyphfont.FontAwesome5;
+import com.sparrowwallet.sparrow.net.MempoolRateSize;
+import com.sparrowwallet.sparrow.wallet.SendController;
+import javafx.application.Platform;
+import javafx.beans.NamedArg;
+import javafx.collections.FXCollections;
+import javafx.geometry.Point2D;
+import javafx.scene.Cursor;
+import javafx.scene.Node;
+import javafx.scene.chart.*;
+import javafx.scene.control.Label;
+import javafx.scene.control.Tooltip;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.VBox;
+import javafx.util.Duration;
+import javafx.util.StringConverter;
+import org.controlsfx.glyphfont.Glyph;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class MempoolSizeFeeRatesChart extends StackedAreaChart<String, Number> {
+    private static final DateFormat dateFormatter = new SimpleDateFormat("HH:mm");
+    public static final int MAX_PERIOD_HOURS = 2;
+
+    private Tooltip tooltip;
+
+    public MempoolSizeFeeRatesChart(@NamedArg("xAxis") Axis<String> xAxis, @NamedArg("yAxis") Axis<Number> yAxis) {
+        super(xAxis, yAxis);
+    }
+
+    public void initialize() {
+        setCreateSymbols(false);
+        setCursor(Cursor.CROSSHAIR);
+        setVerticalGridLinesVisible(false);
+        tooltip = new Tooltip();
+        tooltip.setShowDelay(Duration.ZERO);
+        tooltip.setHideDelay(Duration.ZERO);
+        tooltip.setShowDuration(Duration.INDEFINITE);
+        Platform.runLater(() -> {
+            Node node = this.lookup(".plot-content");
+            Tooltip.install(node, tooltip);
+        });
+    }
+
+    public void update(Map<Date, Set<MempoolRateSize>> mempoolRateSizes) {
+        getData().clear();
+        if(tooltip.isShowing()) {
+            tooltip.hide();
+        }
+
+        Map<Date, Set<MempoolRateSize>> periodRateSizes = getPeriodRateSizes(mempoolRateSizes);
+        Map<Date, String> categories = getCategories(periodRateSizes);
+
+        CategoryAxis categoryAxis = (CategoryAxis)getXAxis();
+        categoryAxis.setTickMarkVisible(false);
+        categoryAxis.setTickLabelGap(10);
+        categoryAxis.setAutoRanging(false);
+        categoryAxis.setCategories(FXCollections.observableArrayList(categories.values()));
+        categoryAxis.invalidateRange(new ArrayList<>(categories.values()));
+        categoryAxis.setGapStartAndEnd(false);
+        categoryAxis.setTickLabelRotation(0);
+
+        NumberAxis numberAxis = (NumberAxis)getYAxis();
+        numberAxis.setTickLabelFormatter(new StringConverter<Number>() {
+            @Override
+            public String toString(Number object) {
+                long vSizeBytes = object.longValue();
+                return (vSizeBytes / (1000 * 1000)) + " MvB";
+            }
+
+            @Override
+            public Number fromString(String string) {
+                return null;
+            }
+        });
+
+        this.setOnMouseMoved(mouseEvent -> {
+            Point2D sceneCoords = this.localToScene(mouseEvent.getX(), mouseEvent.getY());
+            String category = categoryAxis.getValueForDisplay(categoryAxis.sceneToLocal(sceneCoords).getX());
+            if(category != null) {
+                Optional<String> time = categories.entrySet().stream().filter(entry -> entry.getValue().equals(category)).map(entry -> dateFormatter.format(entry.getKey())).findFirst();
+                time.ifPresent(s -> tooltip.setGraphic(new ChartTooltip(category, s, getData())));
+            }
+        });
+
+        long previousFeeRate = 0;
+        for(Long feeRate : SendController.FEE_RATES_RANGE) {
+            XYChart.Series<String, Number> series = new XYChart.Series<>();
+            series.setName(feeRate + "+ vB");
+            long seriesTotalVSize = 0;
+
+            for(Date date : periodRateSizes.keySet()) {
+                Set<MempoolRateSize> rateSizes = periodRateSizes.get(date);
+                long totalVSize = 0;
+                for(MempoolRateSize rateSize : rateSizes) {
+                    if(rateSize.getFee() > previousFeeRate && rateSize.getFee() <= feeRate) {
+                        totalVSize += rateSize.getVSize();
+                    }
+                }
+
+                series.getData().add(new XYChart.Data<>(categories.get(date), totalVSize));
+                seriesTotalVSize += totalVSize;
+            }
+
+            if(seriesTotalVSize > 0) {
+                getData().add(series);
+            }
+
+            previousFeeRate = feeRate;
+        }
+
+        if(categories.keySet().iterator().hasNext()) {
+            String time = categories.values().iterator().next();
+            tooltip.setGraphic(new ChartTooltip(time, time, getData()));
+            numberAxis.setTickLabelsVisible(true);
+            numberAxis.setOpacity(1);
+        } else {
+            numberAxis.setTickLabelsVisible(false);
+            numberAxis.setOpacity(0);
+        }
+    }
+
+    private Map<Date, Set<MempoolRateSize>> getPeriodRateSizes(Map<Date, Set<MempoolRateSize>> mempoolRateSizes) {
+        if(mempoolRateSizes.size() == 1) {
+            return mempoolRateSizes;
+        }
+
+        LocalDateTime period = LocalDateTime.now().minusHours(MAX_PERIOD_HOURS);
+        return mempoolRateSizes.entrySet().stream().filter(entry -> {
+            LocalDateTime dateTime = entry.getKey().toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();
+            return dateTime.isAfter(period);
+        }).collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,
+                (u, v) -> { throw new IllegalStateException("Duplicate dates"); },
+                TreeMap::new));
+    }
+
+    private Map<Date, String> getCategories(Map<Date, Set<MempoolRateSize>> mempoolHistogram) {
+        Map<Date, String> categories = new LinkedHashMap<>();
+
+        String invisible = "" + '\ufeff';
+        for(Iterator<Date> iter = mempoolHistogram.keySet().iterator(); iter.hasNext(); ) {
+            Date date = iter.next();
+            String label = dateFormatter.format(date);
+            if(!categories.isEmpty() && iter.hasNext()) {
+                label = invisible;
+                invisible += '\ufeff';
+            }
+
+            categories.put(date, label);
+        }
+
+        return categories;
+    }
+
+    private static class ChartTooltip extends VBox {
+        public ChartTooltip(String category, String time, List<Series<String, Number>> seriesList) {
+            Label title = new Label("At " + time);
+            HBox titleBox = new HBox(title);
+            title.setStyle("-fx-alignment: center; -fx-font-size: 12px; -fx-padding: 0 0 5 0;");
+            getChildren().add(titleBox);
+
+            for(int i = seriesList.size() - 1; i >= 0; i--) {
+                Series<String, Number> series = seriesList.get(i);
+                for(XYChart.Data<String, Number> data : series.getData()) {
+                    if(data.getXValue().equals(category)) {
+                        double mvb = data.getYValue().doubleValue() / (1000 * 1000);
+                        if(mvb >= 0.01) {
+                            Label label = new Label(series.getName() + ": " + String.format("%.2f", mvb) + " MvB");
+                            Glyph circle = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.CIRCLE);
+                            if(i < 8) {
+                                circle.setStyle("-fx-text-fill: CHART_COLOR_" + (i+1));
+                            }
+                            label.setGraphic(circle);
+                            getChildren().add(label);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/com/sparrowwallet/sparrow/control/MnemonicKeystoreImportPane.java

@@ -2,6 +2,7 @@ package com.sparrowwallet.sparrow.control;
 
 import com.sparrowwallet.drongo.KeyDerivation;
 import com.sparrowwallet.drongo.crypto.ChildNumber;
+import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.wallet.*;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.KeystoreImportEvent;
@@ -107,7 +108,8 @@ public class MnemonicKeystoreImportPane extends TitledDescriptionPane {
             importKeystore(wallet.getScriptType().getDefaultDerivation(), false);
         });
         String[] accounts = new String[] {"Default Account #0", "Account #1", "Account #2", "Account #3", "Account #4", "Account #5", "Account #6", "Account #7", "Account #8", "Account #9"};
-        for(int i = 0; i < accounts.length; i++) {
+        int scriptAccountsLength = ScriptType.P2SH.equals(wallet.getScriptType()) ? 1 : accounts.length;
+        for(int i = 0; i < scriptAccountsLength; i++) {
             MenuItem item = new MenuItem(accounts[i]);
             final List<ChildNumber> derivation = wallet.getScriptType().getDefaultDerivation(i);
             item.setOnAction(event -> {

src/main/java/com/sparrowwallet/sparrow/control/QRDisplayDialog.java

@@ -5,20 +5,22 @@ import com.google.zxing.client.j2se.MatrixToImageConfig;
 import com.google.zxing.client.j2se.MatrixToImageWriter;
 import com.google.zxing.common.BitMatrix;
 import com.google.zxing.qrcode.QRCodeWriter;
+import com.sparrowwallet.hummingbird.LegacyUREncoder;
+import com.sparrowwallet.hummingbird.registry.RegistryType;
 import com.sparrowwallet.sparrow.AppController;
+import com.sparrowwallet.sparrow.glyphfont.FontAwesome5;
 import com.sparrowwallet.sparrow.io.ImportException;
-import com.sparrowwallet.sparrow.ur.UR;
-import com.sparrowwallet.sparrow.ur.UREncoder;
+import com.sparrowwallet.hummingbird.UR;
+import com.sparrowwallet.hummingbird.UREncoder;
 import javafx.concurrent.ScheduledService;
 import javafx.concurrent.Task;
-import javafx.scene.control.ButtonBar;
-import javafx.scene.control.ButtonType;
-import javafx.scene.control.Dialog;
-import javafx.scene.control.DialogPane;
+import javafx.scene.Node;
+import javafx.scene.control.*;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.StackPane;
 import javafx.util.Duration;
+import org.controlsfx.glyphfont.Glyph;
 import org.controlsfx.tools.Borders;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -26,28 +28,41 @@ import org.slf4j.LoggerFactory;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 
+@SuppressWarnings("deprecation")
 public class QRDisplayDialog extends Dialog<UR> {
     private static final Logger log = LoggerFactory.getLogger(QRDisplayDialog.class);
 
     private static final int MIN_FRAGMENT_LENGTH = 10;
     private static final int MAX_FRAGMENT_LENGTH = 100;
 
+    private static final int ANIMATION_PERIOD_MILLIS = 400;
+
     private final UR ur;
     private final UREncoder encoder;
 
     private final ImageView qrImageView;
 
+    private AnimateQRService animateQRService;
     private String currentPart;
 
-    public QRDisplayDialog(byte[] data) {
-        this(UR.fromBytes(data));
+    private boolean useLegacyEncoding;
+    private String[] legacyParts;
+    private int legacyPartIndex;
+
+    public QRDisplayDialog(String type, byte[] data, boolean addLegacyEncodingOption) throws UR.URException {
+        this(UR.fromBytes(type, data), addLegacyEncodingOption);
     }
 
     public QRDisplayDialog(UR ur) {
+        this(ur, false);
+    }
+
+    public QRDisplayDialog(UR ur, boolean addLegacyEncodingOption) {
         this.ur = ur;
         this.encoder = new UREncoder(ur, MAX_FRAGMENT_LENGTH, MIN_FRAGMENT_LENGTH, 0);
 
-        final DialogPane dialogPane = getDialogPane();
+        final DialogPane dialogPane = new QRDisplayDialogPane();
+        setDialogPane(dialogPane);
         AppController.setStageIcon(dialogPane.getScene().getWindow());
 
         StackPane stackPane = new StackPane();
@@ -60,8 +75,8 @@ public class QRDisplayDialog extends Dialog<UR> {
         if(encoder.isSinglePart()) {
             qrImageView.setImage(getQrCode(currentPart));
         } else {
-            AnimateQRService animateQRService = new AnimateQRService();
-            animateQRService.setPeriod(Duration.millis(100));
+            animateQRService = new AnimateQRService();
+            animateQRService.setPeriod(Duration.millis(ANIMATION_PERIOD_MILLIS));
             animateQRService.start();
             setOnCloseRequest(event -> {
                 animateQRService.cancel();
@@ -69,7 +84,13 @@ public class QRDisplayDialog extends Dialog<UR> {
         }
 
         final ButtonType cancelButtonType = new javafx.scene.control.ButtonType("Cancel", ButtonBar.ButtonData.CANCEL_CLOSE);
-        dialogPane.getButtonTypes().addAll(cancelButtonType);
+        dialogPane.getButtonTypes().add(cancelButtonType);
+
+        if(addLegacyEncodingOption) {
+            final ButtonType legacyEncodingButtonType = new javafx.scene.control.ButtonType("Use Legacy Encoding (Cobo Vault)", ButtonBar.ButtonData.LEFT);
+            dialogPane.getButtonTypes().add(legacyEncodingButtonType);
+        }
+
         dialogPane.setPrefWidth(500);
         dialogPane.setPrefHeight(550);
 
@@ -99,8 +120,16 @@ public class QRDisplayDialog extends Dialog<UR> {
     }
 
     private void nextPart() {
-        String fragment = encoder.nextPart();
-        currentPart = fragment.toUpperCase();
+        if(!useLegacyEncoding) {
+            String fragment = encoder.nextPart();
+            currentPart = fragment.toUpperCase();
+        } else {
+            currentPart = legacyParts[legacyPartIndex];
+            legacyPartIndex++;
+            if(legacyPartIndex > legacyParts.length - 1) {
+                legacyPartIndex = 0;
+            }
+        }
     }
 
     private Image getQrCode(String fragment) {
@@ -120,6 +149,44 @@ public class QRDisplayDialog extends Dialog<UR> {
         return null;
     }
 
+    private void setUseLegacyEncoding(boolean useLegacyEncoding) {
+        if(useLegacyEncoding) {
+            try {
+                //Force to be bytes type for legacy encoding
+                LegacyUREncoder legacyEncoder = new LegacyUREncoder(new UR(RegistryType.BYTES.toString(), ur.getCborBytes()));
+                this.legacyParts = legacyEncoder.encode();
+                this.useLegacyEncoding = true;
+
+                if(legacyParts.length == 1) {
+                    if(animateQRService != null) {
+                        animateQRService.cancel();
+                    }
+
+                    nextPart();
+                    qrImageView.setImage(getQrCode(currentPart));
+                } else if(!animateQRService.isRunning()) {
+                    animateQRService.reset();
+                    animateQRService.start();
+                }
+            } catch(UR.InvalidTypeException e) {
+                //Can't happen
+            }
+        } else {
+            this.useLegacyEncoding = false;
+
+            if(encoder.isSinglePart()) {
+                if(animateQRService != null) {
+                    animateQRService.cancel();
+                }
+
+                qrImageView.setImage(getQrCode(currentPart));
+            } else if(!animateQRService.isRunning()) {
+                animateQRService.reset();
+                animateQRService.start();
+            }
+        }
+    }
+
     private class AnimateQRService extends ScheduledService<Boolean> {
         @Override
         protected Task<Boolean> createTask() {
@@ -134,4 +201,44 @@ public class QRDisplayDialog extends Dialog<UR> {
             };
         }
     }
+
+    private class QRDisplayDialogPane extends DialogPane {
+        @Override
+        protected Node createButton(ButtonType buttonType) {
+            if(buttonType.getButtonData() == ButtonBar.ButtonData.LEFT) {
+                ToggleButton legacy = new ToggleButton(buttonType.getText());
+                legacy.setGraphicTextGap(5);
+                setLegacyGraphic(legacy, false);
+
+                final ButtonBar.ButtonData buttonData = buttonType.getButtonData();
+                ButtonBar.setButtonData(legacy, buttonData);
+                legacy.selectedProperty().addListener((observable, oldValue, newValue) -> {
+                    setUseLegacyEncoding(newValue);
+                    setLegacyGraphic(legacy, newValue);
+                });
+
+                return legacy;
+            }
+
+            return super.createButton(buttonType);
+        }
+
+        private void setLegacyGraphic(ToggleButton legacy, boolean useLegacyEncoding) {
+            if(useLegacyEncoding) {
+                legacy.setGraphic(getGlyph(FontAwesome5.Glyph.CHECK_CIRCLE, "success"));
+            } else {
+                legacy.setGraphic(getGlyph(FontAwesome5.Glyph.QUESTION_CIRCLE, null));
+            }
+        }
+
+        private Glyph getGlyph(FontAwesome5.Glyph glyphName, String styleClass) {
+            Glyph glyph = new Glyph(FontAwesome5.FONT_NAME, glyphName);
+            glyph.setFontSize(12);
+            if(styleClass != null) {
+                glyph.getStyleClass().add(styleClass);
+            }
+
+            return glyph;
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java

@@ -2,16 +2,27 @@ package com.sparrowwallet.sparrow.control;
 
 import com.github.sarxos.webcam.WebcamResolution;
 import com.sparrowwallet.drongo.ExtendedKey;
+import com.sparrowwallet.drongo.KeyDerivation;
+import com.sparrowwallet.drongo.OutputDescriptor;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.address.Address;
+import com.sparrowwallet.drongo.address.P2PKHAddress;
+import com.sparrowwallet.drongo.address.P2SHAddress;
+import com.sparrowwallet.drongo.address.P2WPKHAddress;
+import com.sparrowwallet.drongo.crypto.*;
 import com.sparrowwallet.drongo.protocol.Base43;
+import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.protocol.Transaction;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.uri.BitcoinURI;
+import com.sparrowwallet.drongo.wallet.Keystore;
+import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.hummingbird.LegacyURDecoder;
+import com.sparrowwallet.hummingbird.registry.*;
 import com.sparrowwallet.sparrow.AppController;
-import com.sparrowwallet.sparrow.ur.ResultType;
-import com.sparrowwallet.sparrow.ur.UR;
-import com.sparrowwallet.sparrow.ur.URDecoder;
+import com.sparrowwallet.hummingbird.ResultType;
+import com.sparrowwallet.hummingbird.UR;
+import com.sparrowwallet.hummingbird.URDecoder;
 import javafx.application.Platform;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
@@ -21,16 +32,35 @@ import javafx.scene.control.Dialog;
 import javafx.scene.control.DialogPane;
 import javafx.scene.layout.StackPane;
 import org.controlsfx.tools.Borders;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.StandardCharsets;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.IntStream;
+
+@SuppressWarnings("deprecation")
 public class QRScanDialog extends Dialog<QRScanDialog.Result> {
+    private static final Logger log = LoggerFactory.getLogger(QRScanDialog.class);
+
     private final URDecoder decoder;
+    private final LegacyURDecoder legacyDecoder;
     private final WebcamService webcamService;
+    private List<String> parts;
 
     private boolean isUr;
     private QRScanDialog.Result result;
 
+    private static final Pattern PART_PATTERN = Pattern.compile("p(\\d+)of(\\d+) (.+)");
+
     public QRScanDialog() {
         this.decoder = new URDecoder();
+        this.legacyDecoder = new LegacyURDecoder();
 
         this.webcamService = new WebcamService(WebcamResolution.VGA);
         WebcamView webcamView = new WebcamView(webcamService);
@@ -69,38 +99,64 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
 
             //Try text first
             String qrtext = qrResult.getText();
+            Matcher partMatcher = PART_PATTERN.matcher(qrtext);
+
             if(isUr || qrtext.toLowerCase().startsWith(UR.UR_PREFIX)) {
                 isUr = true;
-                decoder.receivePart(qrtext);
 
-                if(decoder.getResult() != null) {
-                    URDecoder.Result urResult = decoder.getResult();
-                    if(urResult.type == ResultType.SUCCESS) {
-                        //TODO: Confirm once UR type registry is updated
-                        if(urResult.ur.getType().contains(UR.BYTES_TYPE) || urResult.ur.getType().equals(UR.CRYPTO_PSBT_TYPE)) {
-                            try {
-                                PSBT psbt = new PSBT(urResult.ur.toBytes());
-                                result = new Result(psbt);
-                                return;
-                            } catch(Exception e) {
-                                //ignore, bytes not parsable as PSBT
-                            }
+                if(LegacyURDecoder.isLegacyURFragment(qrtext)) {
+                    legacyDecoder.receivePart(qrtext.toLowerCase());
 
-                            try {
-                                Transaction transaction = new Transaction(urResult.ur.toBytes());
-                                result = new Result(transaction);
-                                return;
-                            } catch(Exception e) {
-                                //ignore, bytes not parsable as tx
-                            }
-
-                            result = new Result("Parsed UR of type " + urResult.ur.getType() + " was not a PSBT or transaction");
-                        } else {
-                            result = new Result("Cannot parse UR type of " + urResult.ur.getType());
+                    if(legacyDecoder.isComplete()) {
+                        try {
+                            UR ur = legacyDecoder.decode();
+                            result = extractResultFromUR(ur);
+                        } catch(Exception e) {
+                            result = new Result(new URException(e.getMessage()));
                         }
-                    } else {
-                        result = new Result(urResult.error);
                     }
+                } else {
+                    decoder.receivePart(qrtext);
+
+                    if(decoder.getResult() != null) {
+                        URDecoder.Result urResult = decoder.getResult();
+                        if(urResult.type == ResultType.SUCCESS) {
+                            result = extractResultFromUR(urResult.ur);
+                        } else {
+                            result = new Result(new URException(urResult.error));
+                        }
+                    }
+                }
+            } else if(partMatcher.matches()) {
+                int m = Integer.parseInt(partMatcher.group(1));
+                int n = Integer.parseInt(partMatcher.group(2));
+                String payload = partMatcher.group(3);
+
+                if(parts == null) {
+                    parts = new ArrayList<>(n);
+                    IntStream.range(0, n).forEach(i -> parts.add(null));
+                }
+                parts.set(m - 1, payload);
+
+                if(parts.stream().filter(Objects::nonNull).count() == n) {
+                    String complete = String.join("", parts);
+                    try {
+                        PSBT psbt = PSBT.fromString(complete);
+                        result = new Result(psbt);
+                        return;
+                    } catch(Exception e) {
+                        //ignore, bytes not parsable as PSBT
+                    }
+
+                    try {
+                        Transaction transaction = new Transaction(Utils.hexToBytes(complete));
+                        result = new Result(transaction);
+                        return;
+                    } catch(Exception e) {
+                        //ignore, bytes not parsable as tx
+                    }
+
+                    result = new Result(new ScanException("Parsed QR parts were not a PSBT or transaction"));
                 }
             } else {
                 PSBT psbt;
@@ -166,7 +222,7 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
 
                 //Try Base43 used by Electrum
                 try {
-                    psbt = new PSBT(Base43.decode(qrResult.getText()));
+                    psbt = new PSBT(Base43.decode(qrtext));
                     result = new Result(psbt);
                     return;
                 } catch(Exception e) {
@@ -174,16 +230,199 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
                 }
 
                 try {
-                    transaction = new Transaction(Base43.decode(qrResult.getText()));
+                    transaction = new Transaction(Base43.decode(qrtext));
                     result = new Result(transaction);
                     return;
                 } catch(Exception e) {
                     //Ignore, not parseable as base43 decoded bytes
                 }
 
-                result = new Result("Cannot parse QR code into a PSBT, transaction or address");
+                result = new Result(qrtext);
             }
         }
+
+        private Result extractResultFromUR(UR ur) {
+            try {
+                RegistryType urRegistryType = ur.getRegistryType();
+
+                if(urRegistryType.equals(RegistryType.BYTES)) {
+                    byte[] urBytes = (byte[])ur.decodeFromRegistry();
+                    try {
+                        PSBT psbt = new PSBT(urBytes);
+                        return new Result(psbt);
+                    } catch(Exception e) {
+                        //ignore, bytes not parsable as PSBT
+                    }
+
+                    try {
+                        Transaction transaction = new Transaction(urBytes);
+                        return new Result(transaction);
+                    } catch(Exception e) {
+                        //ignore, bytes not parsable as tx
+                    }
+
+                    try {
+                        CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder();
+                        ByteBuffer buf = ByteBuffer.wrap(urBytes);
+                        CharBuffer charBuffer = decoder.decode(buf);
+                        return new Result(charBuffer.toString());
+                    } catch(Exception e) {
+                        //ignore, bytes not parsable as utf-8
+                    }
+
+                    result = new Result(new URException("Parsed UR of type " + urRegistryType + " was not a PSBT, transaction or UTF-8 text"));
+                } else if(urRegistryType.equals(RegistryType.CRYPTO_PSBT)) {
+                    CryptoPSBT cryptoPSBT = (CryptoPSBT)ur.decodeFromRegistry();
+                    try {
+                        PSBT psbt = new PSBT(cryptoPSBT.getPsbt());
+                        return new Result(psbt);
+                    } catch(Exception e) {
+                        log.error("Error parsing PSBT from UR type " + urRegistryType, e);
+                        return new Result(new URException("Error parsing PSBT from UR type " + urRegistryType, e));
+                    }
+                } else if(urRegistryType.equals(RegistryType.CRYPTO_ADDRESS)) {
+                    CryptoAddress cryptoAddress = (CryptoAddress)ur.decodeFromRegistry();
+                    Address address = getAddress(cryptoAddress);
+                    if(address != null) {
+                        return new Result(BitcoinURI.fromAddress(address));
+                    } else {
+                        return new Result(new URException("Unknown " + urRegistryType + " type of " + cryptoAddress.getType()));
+                    }
+                } else if(urRegistryType.equals(RegistryType.CRYPTO_HDKEY)) {
+                    CryptoHDKey cryptoHDKey = (CryptoHDKey)ur.decodeFromRegistry();
+                    ExtendedKey extendedKey = getExtendedKey(cryptoHDKey);
+                    return new Result(extendedKey);
+                } else if(urRegistryType.equals(RegistryType.CRYPTO_OUTPUT)) {
+                    CryptoOutput cryptoOutput = (CryptoOutput)ur.decodeFromRegistry();
+                    OutputDescriptor outputDescriptor = getOutputDescriptor(cryptoOutput);
+                    return new Result(outputDescriptor);
+                } else if(urRegistryType.equals(RegistryType.CRYPTO_ACCOUNT)) {
+                    CryptoAccount cryptoAccount = (CryptoAccount)ur.decodeFromRegistry();
+                    List<Wallet> wallets = getWallets(cryptoAccount);
+                    return new Result(wallets);
+                } else {
+                    log.error("Unsupported UR type " + urRegistryType);
+                    return new Result(new URException("UR type " + urRegistryType + " is not supported"));
+                }
+            } catch(IllegalArgumentException e) {
+                log.error("Unknown UR type of " + ur.getType(), e);
+                return new Result(new URException("Unknown UR type of " + ur.getType(), e));
+            } catch(UR.InvalidCBORException e) {
+                log.error("Invalid CBOR in UR", e);
+                return new Result(new URException("Invalid CBOR in UR", e));
+            } catch(Exception e) {
+                log.error("Error parsing UR CBOR", e);
+                return new Result(new URException("Error parsing UR CBOR", e));
+            }
+
+            return null;
+        }
+
+        private Address getAddress(CryptoAddress cryptoAddress) {
+            Address address = null;
+            if(cryptoAddress.getType() == null || cryptoAddress.getType() == CryptoAddress.Type.P2PKH) {
+                address = new P2PKHAddress(cryptoAddress.getData());
+            } else if(cryptoAddress.getType() == CryptoAddress.Type.P2SH) {
+                address = new P2SHAddress(cryptoAddress.getData());
+            } else if(cryptoAddress.getType() == CryptoAddress.Type.P2WPKH) {
+                address = new P2WPKHAddress(cryptoAddress.getData());
+            }
+            return address;
+        }
+
+        private ExtendedKey getExtendedKey(CryptoHDKey cryptoHDKey) {
+            if(cryptoHDKey.isPrivateKey()) {
+                DeterministicKey prvKey = HDKeyDerivation.createMasterPrivKeyFromBytes(Arrays.copyOfRange(cryptoHDKey.getKey(), 1, 33), cryptoHDKey.getChainCode(), List.of(ChildNumber.ZERO));
+                return new ExtendedKey(prvKey, new byte[4], ChildNumber.ZERO);
+            } else {
+                ChildNumber lastChild = ChildNumber.ZERO;
+                int depth = 1;
+                byte[] parentFingerprint = new byte[4];
+                if(cryptoHDKey.getOrigin() != null) {
+                    if(!cryptoHDKey.getOrigin().getComponents().isEmpty()) {
+                        PathComponent lastComponent = cryptoHDKey.getOrigin().getComponents().get(cryptoHDKey.getOrigin().getComponents().size() - 1);
+                        lastChild = new ChildNumber(lastComponent.getIndex(), lastComponent.isHardened());
+                        depth = cryptoHDKey.getOrigin().getComponents().size();
+                    }
+                    if(cryptoHDKey.getParentFingerprint() != null) {
+                        parentFingerprint = cryptoHDKey.getParentFingerprint();
+                    }
+                }
+                DeterministicKey pubKey = new DeterministicKey(List.of(lastChild), cryptoHDKey.getChainCode(), cryptoHDKey.getKey(), depth, parentFingerprint);
+                return new ExtendedKey(pubKey, parentFingerprint, lastChild);
+            }
+        }
+
+        private OutputDescriptor getOutputDescriptor(CryptoOutput cryptoOutput) {
+            ScriptType scriptType = getScriptType(cryptoOutput.getScriptExpressions());
+
+            if(cryptoOutput.getMultiKey() != null) {
+                MultiKey multiKey = cryptoOutput.getMultiKey();
+                Map<ExtendedKey, KeyDerivation> extendedPublicKeys = new LinkedHashMap<>();
+                for(CryptoHDKey cryptoHDKey : multiKey.getHdKeys()) {
+                    ExtendedKey extendedKey = getExtendedKey(cryptoHDKey);
+                    KeyDerivation keyDerivation = getKeyDerivation(cryptoHDKey.getOrigin());
+                    extendedPublicKeys.put(extendedKey, keyDerivation);
+                }
+                return new OutputDescriptor(scriptType, multiKey.getThreshold(), extendedPublicKeys);
+            } else if(cryptoOutput.getEcKey() != null) {
+                throw new IllegalArgumentException("EC keys are currently unsupported");
+            } else if(cryptoOutput.getHdKey() != null) {
+                ExtendedKey extendedKey = getExtendedKey(cryptoOutput.getHdKey());
+                KeyDerivation keyDerivation = getKeyDerivation(cryptoOutput.getHdKey().getOrigin());
+                return new OutputDescriptor(scriptType, extendedKey, keyDerivation);
+            }
+
+            throw new IllegalStateException("CryptoOutput did not contain sufficient information");
+        }
+
+        private List<Wallet> getWallets(CryptoAccount cryptoAccount) {
+            List<Wallet> wallets = new ArrayList<>();
+            String masterFingerprint = Utils.bytesToHex(cryptoAccount.getMasterFingerprint());
+            for(CryptoOutput cryptoOutput : cryptoAccount.getOutputDescriptors()) {
+                Wallet wallet = new Wallet();
+                OutputDescriptor outputDescriptor = getOutputDescriptor(cryptoOutput);
+                if(outputDescriptor.isMultisig()) {
+                    throw new IllegalStateException("Multisig output descriptors are unsupported in CryptoAccount");
+                }
+
+                ExtendedKey extendedKey = outputDescriptor.getSingletonExtendedPublicKey();
+                wallet.setScriptType(outputDescriptor.getScriptType());
+                Keystore keystore = new Keystore();
+                keystore.setKeyDerivation(new KeyDerivation(masterFingerprint, outputDescriptor.getKeyDerivation(extendedKey).getDerivationPath()));
+                keystore.setExtendedPublicKey(extendedKey);
+                wallet.getKeystores().add(keystore);
+                wallets.add(wallet);
+            }
+
+            return wallets;
+        }
+
+        private ScriptType getScriptType(List<ScriptExpression> expressions) {
+            if(List.of(ScriptExpression.PUBLIC_KEY_HASH).equals(expressions)) {
+                return ScriptType.P2PKH;
+            } else if(List.of(ScriptExpression.SCRIPT_HASH, ScriptExpression.WITNESS_PUBLIC_KEY_HASH).equals(expressions)) {
+                return ScriptType.P2SH_P2WPKH;
+            } else if(List.of(ScriptExpression.WITNESS_PUBLIC_KEY_HASH).equals(expressions)) {
+                return ScriptType.P2WPKH;
+            } else if(List.of(ScriptExpression.SCRIPT_HASH).equals(expressions)) {
+                return ScriptType.P2SH;
+            } else if(List.of(ScriptExpression.SCRIPT_HASH, ScriptExpression.WITNESS_SCRIPT_HASH).equals(expressions)) {
+                return ScriptType.P2SH_P2WSH;
+            } else if(List.of(ScriptExpression.WITNESS_SCRIPT_HASH).equals(expressions)) {
+                return ScriptType.P2WSH;
+            }
+
+            throw new IllegalArgumentException("Unknown script of " + expressions);
+        }
+
+        private KeyDerivation getKeyDerivation(CryptoKeypath cryptoKeypath) {
+            if(cryptoKeypath != null) {
+                return new KeyDerivation(Utils.bytesToHex(cryptoKeypath.getSourceFingerprint()), cryptoKeypath.getPath());
+            }
+
+            return null;
+        }
     }
 
     public static class Result {
@@ -191,7 +430,9 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
         public final PSBT psbt;
         public final BitcoinURI uri;
         public final ExtendedKey extendedKey;
-        public final String error;
+        public final OutputDescriptor outputDescriptor;
+        public final List<Wallet> wallets;
+        public final String payload;
         public final Throwable exception;
 
         public Result(Transaction transaction) {
@@ -199,7 +440,9 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = null;
             this.uri = null;
             this.extendedKey = null;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = null;
         }
 
@@ -208,7 +451,9 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = psbt;
             this.uri = null;
             this.extendedKey = null;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = null;
         }
 
@@ -217,7 +462,9 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = null;
             this.uri = uri;
             this.extendedKey = null;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = null;
         }
 
@@ -226,7 +473,9 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = null;
             this.uri = BitcoinURI.fromAddress(address);
             this.extendedKey = null;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = null;
         }
 
@@ -235,16 +484,42 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = null;
             this.uri = null;
             this.extendedKey = extendedKey;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = null;
         }
 
-        public Result(String error) {
+        public Result(OutputDescriptor outputDescriptor) {
             this.transaction = null;
             this.psbt = null;
             this.uri = null;
             this.extendedKey = null;
-            this.error = error;
+            this.outputDescriptor = outputDescriptor;
+            this.wallets = null;
+            this.payload = null;
+            this.exception = null;
+        }
+
+        public Result(List<Wallet> wallets) {
+            this.transaction = null;
+            this.psbt = null;
+            this.uri = null;
+            this.extendedKey = null;
+            this.outputDescriptor = null;
+            this.wallets = wallets;
+            this.payload = null;
+            this.exception = null;
+        }
+
+        public Result(String payload) {
+            this.transaction = null;
+            this.psbt = null;
+            this.uri = null;
+            this.extendedKey = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = payload;
             this.exception = null;
         }
 
@@ -253,8 +528,46 @@ public class QRScanDialog extends Dialog<QRScanDialog.Result> {
             this.psbt = null;
             this.uri = null;
             this.extendedKey = null;
-            this.error = null;
+            this.outputDescriptor = null;
+            this.wallets = null;
+            this.payload = null;
             this.exception = exception;
         }
     }
+
+    public static class ScanException extends Exception {
+        public ScanException() {
+            super();
+        }
+
+        public ScanException(String message) {
+            super(message);
+        }
+
+        public ScanException(Throwable cause) {
+            super(cause);
+        }
+
+        public ScanException(String message, Throwable cause) {
+            super(message, cause);
+        }
+    }
+
+    public static class URException extends ScanException {
+        public URException() {
+            super();
+        }
+
+        public URException(String message) {
+            super(message);
+        }
+
+        public URException(Throwable cause) {
+            super(cause);
+        }
+
+        public URException(String message, Throwable cause) {
+            super(message, cause);
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/control/TransactionDiagram.java

@@ -1,9 +1,13 @@
 package com.sparrowwallet.sparrow.control;
 
+import com.sparrowwallet.drongo.address.Address;
 import com.sparrowwallet.drongo.protocol.Sha256Hash;
+import com.sparrowwallet.drongo.uri.BitcoinURI;
 import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
+import com.sparrowwallet.drongo.wallet.Payment;
 import com.sparrowwallet.drongo.wallet.WalletNode;
 import com.sparrowwallet.drongo.wallet.WalletTransaction;
+import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.ExcludeUtxoEvent;
 import com.sparrowwallet.sparrow.glyphfont.FontAwesome5;
@@ -23,9 +27,11 @@ import org.controlsfx.glyphfont.FontAwesome;
 import org.controlsfx.glyphfont.Glyph;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class TransactionDiagram extends GridPane {
     private static final int MAX_UTXOS = 8;
+    private static final int MAX_PAYMENTS = 6;
     private static final double DIAGRAM_HEIGHT = 230.0;
     private static final int TOOLTIP_SHOW_DELAY = 50;
 
@@ -55,10 +61,12 @@ public class TransactionDiagram extends GridPane {
         Pane txPane = getTransactionPane();
         GridPane.setConstraints(txPane, 3, 0);
 
-        Pane outputsLinesPane = getOutputsLines();
+        List<Payment> displayedPayments = getDisplayedPayments();
+
+        Pane outputsLinesPane = getOutputsLines(displayedPayments);
         GridPane.setConstraints(outputsLinesPane, 4, 0);
 
-        Pane outputsPane = getOutputsLabels();
+        Pane outputsPane = getOutputsLabels(displayedPayments);
         GridPane.setConstraints(outputsPane, 5, 0);
 
         getChildren().clear();
@@ -68,11 +76,16 @@ public class TransactionDiagram extends GridPane {
     private Map<BlockTransactionHashIndex, WalletNode> getDisplayedUtxos() {
         Map<BlockTransactionHashIndex, WalletNode> selectedUtxos = walletTx.getSelectedUtxos();
 
+        if(getPayjoinURI() != null) {
+            selectedUtxos = new LinkedHashMap<>(selectedUtxos);
+            selectedUtxos.put(new PayjoinBlockTransactionHashIndex(), null);
+        }
+
         if(selectedUtxos.size() > MAX_UTXOS) {
             Map<BlockTransactionHashIndex, WalletNode> utxos = new LinkedHashMap<>();
             List<BlockTransactionHashIndex> additional = new ArrayList<>();
             for(BlockTransactionHashIndex reference : selectedUtxos.keySet()) {
-                if (utxos.size() < MAX_UTXOS) {
+                if(utxos.size() < MAX_UTXOS - 1) {
                     utxos.put(reference, selectedUtxos.get(reference));
                 } else {
                     additional.add(reference);
@@ -86,6 +99,22 @@ public class TransactionDiagram extends GridPane {
         }
     }
 
+    private BitcoinURI getPayjoinURI() {
+        for(Payment payment : walletTx.getPayments()) {
+            try {
+                Address address = payment.getAddress();
+                BitcoinURI bitcoinURI = AppController.getPayjoinURI(address);
+                if(bitcoinURI != null) {
+                    return bitcoinURI;
+                }
+            } catch(Exception e) {
+                //ignore
+            }
+        }
+
+        return null;
+    }
+
     private Pane getInputsType(Map<BlockTransactionHashIndex, WalletNode> displayedUtxos) {
         StackPane stackPane = new StackPane();
 
@@ -160,24 +189,28 @@ public class TransactionDiagram extends GridPane {
                 EventManager.get().post(new ExcludeUtxoEvent(walletTx, input));
             });
 
-            label.setGraphic(excludeUtxoButton);
-            label.setContentDisplay(ContentDisplay.LEFT);
-
             Tooltip tooltip = new Tooltip();
             if(walletNode != null) {
-                tooltip.setText("Spending " + getSatsValue(input.getValue()) + " sats from " + walletNode.getDerivationPath() + "\n" + input.getHashAsString() + ":" + input.getIndex() + "\n" + walletTx.getWallet().getAddress(walletNode));
+                tooltip.setText("Spending " + getSatsValue(input.getValue()) + " sats from " + walletNode.getDerivationPath().replace("m", "..") + "\n" + input.getHashAsString() + ":" + input.getIndex() + "\n" + walletTx.getWallet().getAddress(walletNode));
                 tooltip.getStyleClass().add("input-label");
 
                 if(input.getLabel() == null || input.getLabel().isEmpty()) {
                     label.getStyleClass().add("input-label");
                 }
+
+                label.setGraphic(excludeUtxoButton);
+                label.setContentDisplay(ContentDisplay.LEFT);
             } else {
-                AdditionalBlockTransactionHashIndex additionalReference = (AdditionalBlockTransactionHashIndex)input;
-                StringJoiner joiner = new StringJoiner("\n");
-                for(BlockTransactionHashIndex additionalInput : additionalReference.getAdditionalInputs()) {
-                    joiner.add(getInputDescription(additionalInput));
+                if(input instanceof PayjoinBlockTransactionHashIndex) {
+                    tooltip.setText("Added once transaction is signed and sent to the payjoin server");
+                } else {
+                    AdditionalBlockTransactionHashIndex additionalReference = (AdditionalBlockTransactionHashIndex) input;
+                    StringJoiner joiner = new StringJoiner("\n");
+                    for(BlockTransactionHashIndex additionalInput : additionalReference.getAdditionalInputs()) {
+                        joiner.add(getInputDescription(additionalInput));
+                    }
+                    tooltip.setText(joiner.toString());
                 }
-                tooltip.setText(joiner.toString());
                 tooltip.getStyleClass().add("input-label");
             }
             tooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
@@ -212,11 +245,16 @@ public class TransactionDiagram extends GridPane {
         group.getChildren().add(yaxisLine);
 
         double width = 140.0;
+        List<BlockTransactionHashIndex> inputs = new ArrayList<>(displayedUtxos.keySet());
         int numUtxos = displayedUtxos.size();
         for(int i = 1; i <= numUtxos; i++) {
             CubicCurve curve = new CubicCurve();
             curve.getStyleClass().add("input-line");
 
+            if(inputs.get(numUtxos-i) instanceof PayjoinBlockTransactionHashIndex) {
+                curve.getStyleClass().add("input-dashed-line");
+            }
+
             curve.setStartX(0);
             double scaleFactor = (double)i / (numUtxos + 1);
             int nodeHeight = 17;
@@ -241,7 +279,28 @@ public class TransactionDiagram extends GridPane {
         return value * (1.0 - scaleFactor) + additional;
     }
 
-    private Pane getOutputsLines() {
+    private List<Payment> getDisplayedPayments() {
+        List<Payment> payments = walletTx.getPayments();
+
+        if(payments.size() > MAX_PAYMENTS) {
+            List<Payment> displayedPayments = new ArrayList<>();
+            List<Payment> additional = new ArrayList<>();
+            for(Payment payment : payments) {
+                if(displayedPayments.size() < MAX_PAYMENTS - 1) {
+                    displayedPayments.add(payment);
+                } else {
+                    additional.add(payment);
+                }
+            }
+
+            displayedPayments.add(new AdditionalPayment(additional));
+            return displayedPayments;
+        } else {
+            return payments;
+        }
+    }
+
+    private Pane getOutputsLines(List<Payment> displayedPayments) {
         VBox pane = new VBox();
         Group group = new Group();
         VBox.setVgrow(group, Priority.ALWAYS);
@@ -255,7 +314,7 @@ public class TransactionDiagram extends GridPane {
         group.getChildren().add(yaxisLine);
 
         double width = 140.0;
-        int numOutputs = (walletTx.getChangeNode() == null ? 2 : 3);
+        int numOutputs = displayedPayments.size() + (walletTx.getChangeNode() == null ? 1 : 2);
         for(int i = 1; i <= numOutputs; i++) {
             CubicCurve curve = new CubicCurve();
             curve.getStyleClass().add("output-line");
@@ -280,29 +339,32 @@ public class TransactionDiagram extends GridPane {
         return pane;
     }
 
-    private Pane getOutputsLabels() {
+    private Pane getOutputsLabels(List<Payment> displayedPayments) {
         VBox outputsBox = new VBox();
         outputsBox.setMaxWidth(150);
         outputsBox.setPadding(new Insets(0, 20, 0, 10));
         outputsBox.setAlignment(Pos.CENTER_LEFT);
         outputsBox.getChildren().add(createSpacer());
 
-        boolean isConsolidation = walletTx.isConsolidationSend();
-        String recipientDesc = walletTx.getRecipientAddress().toString().substring(0, 8) + "...";
-        Label recipientLabel = new Label(recipientDesc, isConsolidation ? getConsolidationGlyph() : getPaymentGlyph());
-        recipientLabel.getStyleClass().addAll("output-label", "recipient-label");
-        Tooltip recipientTooltip = new Tooltip((isConsolidation ? "Consolidate " : "Pay ") + getSatsValue(walletTx.getRecipientAmount()) + " sats to\n" + walletTx.getRecipientAddress().toString());
-        recipientTooltip.getStyleClass().add("recipient-label");
-        recipientTooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
-        recipientLabel.setTooltip(recipientTooltip);
-        outputsBox.getChildren().add(recipientLabel);
-        outputsBox.getChildren().add(createSpacer());
+        for(Payment payment : displayedPayments) {
+            boolean isConsolidation = walletTx.isConsolidationSend(payment);
+            String recipientDesc = payment instanceof AdditionalPayment ? payment.getLabel() : payment.getAddress().toString().substring(0, 8) + "...";
+            Label recipientLabel = new Label(recipientDesc, isConsolidation ? getConsolidationGlyph() : getPaymentGlyph());
+            recipientLabel.getStyleClass().add("output-label");
+            recipientLabel.getStyleClass().add(payment instanceof AdditionalPayment ? "additional-label" : "recipient-label");
+            Tooltip recipientTooltip = new Tooltip((isConsolidation ? "Consolidate " : "Pay ") + getSatsValue(payment.getAmount()) + " sats to " + (payment instanceof AdditionalPayment ? "\n" + payment : payment.getLabel() + "\n" + payment.getAddress().toString()));
+            recipientTooltip.getStyleClass().add("recipient-label");
+            recipientTooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
+            recipientLabel.setTooltip(recipientTooltip);
+            outputsBox.getChildren().add(recipientLabel);
+            outputsBox.getChildren().add(createSpacer());
+        }
 
         if(walletTx.getChangeNode() != null) {
             String changeDesc = walletTx.getChangeAddress().toString().substring(0, 8) + "...";
             Label changeLabel = new Label(changeDesc, getChangeGlyph());
             changeLabel.getStyleClass().addAll("output-label", "change-label");
-            Tooltip changeTooltip = new Tooltip("Change of " + getSatsValue(walletTx.getChangeAmount()) + " sats to " + walletTx.getChangeNode().getDerivationPath() + "\n" + walletTx.getChangeAddress().toString());
+            Tooltip changeTooltip = new Tooltip("Change of " + getSatsValue(walletTx.getChangeAmount()) + " sats to " + walletTx.getChangeNode().getDerivationPath().replace("m", "..") + "\n" + walletTx.getChangeAddress().toString());
             changeTooltip.getStyleClass().add("change-label");
             changeTooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
             changeLabel.setTooltip(changeTooltip);
@@ -333,6 +395,8 @@ public class TransactionDiagram extends GridPane {
         String txDesc = "Transaction";
         Label txLabel = new Label(txDesc);
         Tooltip tooltip = new Tooltip(walletTx.getTransaction().getLength() + " bytes\n" + walletTx.getTransaction().getVirtualSize() + " vBytes");
+        tooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
+        tooltip.getStyleClass().add("transaction-tooltip");
         txLabel.setTooltip(tooltip);
         txPane.getChildren().add(txLabel);
         txPane.getChildren().add(createSpacer());
@@ -367,6 +431,17 @@ public class TransactionDiagram extends GridPane {
         return consolidationGlyph;
     }
 
+    public static Glyph getTxoGlyph() {
+        return getChangeGlyph();
+    }
+
+    public static Glyph getPayjoinGlyph() {
+        Glyph payjoinGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.RANDOM);
+        payjoinGlyph.getStyleClass().add("payjoin-icon");
+        payjoinGlyph.setFontSize(12);
+        return payjoinGlyph;
+    }
+
     public static Glyph getChangeGlyph() {
         Glyph changeGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.COINS);
         changeGlyph.getStyleClass().add("change-icon");
@@ -395,6 +470,17 @@ public class TransactionDiagram extends GridPane {
         return lockGlyph;
     }
 
+    private static class PayjoinBlockTransactionHashIndex extends BlockTransactionHashIndex {
+        public PayjoinBlockTransactionHashIndex() {
+            super(Sha256Hash.ZERO_HASH, 0, new Date(), 0L, 0, 0);
+        }
+
+        @Override
+        public String getLabel() {
+            return "Payjoin input";
+        }
+    }
+
     private static class AdditionalBlockTransactionHashIndex extends BlockTransactionHashIndex {
         private final List<BlockTransactionHashIndex> additionalInputs;
 
@@ -412,4 +498,17 @@ public class TransactionDiagram extends GridPane {
             return additionalInputs;
         }
     }
+
+    private static class AdditionalPayment extends Payment {
+        private final List<Payment> additionalPayments;
+
+        public AdditionalPayment(List<Payment> additionalPayments) {
+            super(null, additionalPayments.size() + " more...", additionalPayments.stream().map(Payment::getAmount).mapToLong(v -> v).sum(), false);
+            this.additionalPayments = additionalPayments;
+        }
+
+        public String toString() {
+            return additionalPayments.stream().map(payment -> payment.getAddress().toString()).collect(Collectors.joining("\n"));
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/control/UtxosChart.java

@@ -39,7 +39,7 @@ public class UtxosChart extends BarChart<String, Number> {
     public void update(WalletUtxosEntry walletUtxosEntry) {
         List<Data<String, Number>> utxoDataList = walletUtxosEntry.getChildren().stream()
                 .map(entry -> new XYChart.Data<>(getCategoryName(entry), (Number)entry.getValue(), entry))
-                .sorted((o1, o2) -> (int) (o2.getYValue().longValue() - o1.getYValue().longValue()))
+                .sorted((o1, o2) -> Long.compare(o2.getYValue().longValue(), o1.getYValue().longValue()))
                 .collect(Collectors.toList());
 
         totalUtxos = utxoDataList.size();

src/main/java/com/sparrowwallet/sparrow/event/ConnectionEvent.java

@@ -1,9 +1,11 @@
 package com.sparrowwallet.sparrow.event;
 
 import com.sparrowwallet.drongo.protocol.BlockHeader;
+import com.sparrowwallet.sparrow.net.MempoolRateSize;
 
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 public class ConnectionEvent extends FeeRatesUpdatedEvent {
     private final List<String> serverVersion;
@@ -12,8 +14,8 @@ public class ConnectionEvent extends FeeRatesUpdatedEvent {
     private final BlockHeader blockHeader;
     private final Double minimumRelayFeeRate;
 
-    public ConnectionEvent(List<String> serverVersion, String serverBanner, int blockHeight, BlockHeader blockHeader, Map<Integer, Double> targetBlockFeeRates, Double minimumRelayFeeRate) {
-        super(targetBlockFeeRates);
+    public ConnectionEvent(List<String> serverVersion, String serverBanner, int blockHeight, BlockHeader blockHeader, Map<Integer, Double> targetBlockFeeRates, Set<MempoolRateSize> mempoolRateSizes, Double minimumRelayFeeRate) {
+        super(targetBlockFeeRates, mempoolRateSizes);
         this.serverVersion = serverVersion;
         this.serverBanner = serverBanner;
         this.blockHeight = blockHeight;

src/main/java/com/sparrowwallet/sparrow/event/FeeRatesSelectionChangedEvent.java

@@ -0,0 +1,15 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.sparrow.wallet.FeeRatesSelection;
+
+public class FeeRatesSelectionChangedEvent {
+    private final FeeRatesSelection feeRatesSelection;
+
+    public FeeRatesSelectionChangedEvent(FeeRatesSelection feeRatesSelection) {
+        this.feeRatesSelection = feeRatesSelection;
+    }
+
+    public FeeRatesSelection getFeeRateSelection() {
+        return feeRatesSelection;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/event/FeeRatesSourceChangedEvent.java

@@ -0,0 +1,15 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.sparrow.net.FeeRatesSource;
+
+public class FeeRatesSourceChangedEvent {
+    private final FeeRatesSource feeRatesSource;
+
+    public FeeRatesSourceChangedEvent(FeeRatesSource feeRatesSource) {
+        this.feeRatesSource = feeRatesSource;
+    }
+
+    public FeeRatesSource getFeeRateSource() {
+        return feeRatesSource;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/event/FeeRatesUpdatedEvent.java

@@ -1,15 +1,24 @@
 package com.sparrowwallet.sparrow.event;
 
+import com.sparrowwallet.sparrow.net.MempoolRateSize;
+
 import java.util.Map;
+import java.util.Set;
 
 public class FeeRatesUpdatedEvent {
     private final Map<Integer, Double> targetBlockFeeRates;
+    private final Set<MempoolRateSize> mempoolRateSizes;
 
-    public FeeRatesUpdatedEvent(Map<Integer, Double> targetBlockFeeRates) {
+    public FeeRatesUpdatedEvent(Map<Integer, Double> targetBlockFeeRates, Set<MempoolRateSize> mempoolRateSizes) {
         this.targetBlockFeeRates = targetBlockFeeRates;
+        this.mempoolRateSizes = mempoolRateSizes;
     }
 
     public Map<Integer, Double> getTargetBlockFeeRates() {
         return targetBlockFeeRates;
     }
+
+    public Set<MempoolRateSize> getMempoolRateSizes() {
+        return mempoolRateSizes;
+    }
 }

src/main/java/com/sparrowwallet/sparrow/event/FiatCurrencySelectedEvent.java

@@ -1,6 +1,6 @@
 package com.sparrowwallet.sparrow.event;
 
-import com.sparrowwallet.sparrow.io.ExchangeSource;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
 
 import java.util.Currency;
 

src/main/java/com/sparrowwallet/sparrow/event/SendActionEvent.java

@@ -1,17 +1,24 @@
 package com.sparrowwallet.sparrow.event;
 
-import com.sparrowwallet.sparrow.wallet.HashIndexEntry;
+import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
+import com.sparrowwallet.drongo.wallet.Wallet;
 
 import java.util.List;
 
 public class SendActionEvent {
-    private final List<HashIndexEntry> utxoEntries;
+    private final Wallet wallet;
+    private final List<BlockTransactionHashIndex> utxos;
 
-    public SendActionEvent(List<HashIndexEntry> utxoEntries) {
-        this.utxoEntries = utxoEntries;
+    public SendActionEvent(Wallet wallet, List<BlockTransactionHashIndex> utxos) {
+        this.wallet = wallet;
+        this.utxos = utxos;
     }
 
-    public List<HashIndexEntry> getUtxoEntries() {
-        return utxoEntries;
+    public Wallet getWallet() {
+        return wallet;
+    }
+
+    public List<BlockTransactionHashIndex> getUtxos() {
+        return utxos;
     }
 }

src/main/java/com/sparrowwallet/sparrow/event/SpendUtxoEvent.java

@@ -1,17 +1,47 @@
 package com.sparrowwallet.sparrow.event;
 
-import com.sparrowwallet.sparrow.wallet.HashIndexEntry;
+import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
+import com.sparrowwallet.drongo.wallet.Payment;
+import com.sparrowwallet.drongo.wallet.Wallet;
 
 import java.util.List;
 
 public class SpendUtxoEvent {
-    private final List<HashIndexEntry> utxoEntries;
+    private final Wallet wallet;
+    private final List<BlockTransactionHashIndex> utxos;
+    private final List<Payment> payments;
+    private final Long fee;
+    private final boolean includeMempoolInputs;
 
-    public SpendUtxoEvent(List<HashIndexEntry> utxoEntries) {
-        this.utxoEntries = utxoEntries;
+    public SpendUtxoEvent(Wallet wallet, List<BlockTransactionHashIndex> utxos) {
+        this(wallet, utxos, null, null, false);
     }
 
-    public List<HashIndexEntry> getUtxoEntries() {
-        return utxoEntries;
+    public SpendUtxoEvent(Wallet wallet, List<BlockTransactionHashIndex> utxos, List<Payment> payments, Long fee, boolean includeMempoolInputs) {
+        this.wallet = wallet;
+        this.utxos = utxos;
+        this.payments = payments;
+        this.fee = fee;
+        this.includeMempoolInputs = includeMempoolInputs;
+    }
+
+    public Wallet getWallet() {
+        return wallet;
+    }
+
+    public List<BlockTransactionHashIndex> getUtxos() {
+        return utxos;
+    }
+
+    public List<Payment> getPayments() {
+        return payments;
+    }
+
+    public Long getFee() {
+        return fee;
+    }
+
+    public boolean isIncludeMempoolInputs() {
+        return includeMempoolInputs;
     }
 }

src/main/java/com/sparrowwallet/sparrow/event/WalletHistoryStatusEvent.java

@@ -1,28 +1,38 @@
 package com.sparrowwallet.sparrow.event;
 
+import com.sparrowwallet.drongo.wallet.Wallet;
+
 public class WalletHistoryStatusEvent {
+    private final Wallet wallet;
     private final boolean loaded;
     private final String statusMessage;
     private final String errorMessage;
 
-    public WalletHistoryStatusEvent(boolean loaded) {
+    public WalletHistoryStatusEvent(Wallet wallet, boolean loaded) {
+        this.wallet = wallet;
         this.loaded = loaded;
         this.statusMessage = null;
         this.errorMessage = null;
     }
 
-    public WalletHistoryStatusEvent(boolean loaded, String statusMessage) {
+    public WalletHistoryStatusEvent(Wallet wallet,boolean loaded, String statusMessage) {
+        this.wallet = wallet;
         this.loaded = false;
         this.statusMessage = statusMessage;
         this.errorMessage = null;
     }
 
-    public WalletHistoryStatusEvent(String errorMessage) {
+    public WalletHistoryStatusEvent(Wallet wallet,String errorMessage) {
+        this.wallet = wallet;
         this.loaded = false;
         this.statusMessage = null;
         this.errorMessage = errorMessage;
     }
 
+    public Wallet getWallet() {
+        return wallet;
+    }
+
     public boolean isLoading() {
         return !loaded;
     }

src/main/java/com/sparrowwallet/sparrow/glyphfont/FontAwesome5.java

@@ -30,13 +30,16 @@ public class FontAwesome5 extends GlyphFont {
         ELLIPSIS_H('\uf141'),
         EYE('\uf06e'),
         HAND_HOLDING('\uf4bd'),
+        HAND_HOLDING_MEDICAL('\ue05c'),
         KEY('\uf084'),
         LAPTOP('\uf109'),
         LOCK('\uf023'),
         LOCK_OPEN('\uf3c1'),
         PEN_FANCY('\uf5ac'),
+        PLUS('\uf067'),
         QRCODE('\uf029'),
         QUESTION_CIRCLE('\uf059'),
+        RANDOM('\uf074'),
         REPLY_ALL('\uf122'),
         SATELLITE_DISH('\uf7c0'),
         SD_CARD('\uf7c2'),

src/main/java/com/sparrowwallet/sparrow/io/CoboVaultMultisig.java

@@ -29,7 +29,7 @@ public class CoboVaultMultisig extends ColdcardMultisig {
 
     @Override
     public String getKeystoreImportDescription() {
-        return "Import file created by using the Multisig Wallet > Show/Export XPUB > Export All > Export feature on your Cobo Vault.";
+        return "Import file or QR created by using the Multisig Wallet > Show/Export XPUB feature on your Cobo Vault.";
     }
 
     @Override
@@ -45,11 +45,21 @@ public class CoboVaultMultisig extends ColdcardMultisig {
 
     @Override
     public String getWalletImportDescription() {
-        return "Import file created by using the Multisig Wallet > Create Multisig Wallet feature on your Cobo Vault.";
+        return "Import file or QR created by using the Multisig Wallet > Create Multisig Wallet feature on your Cobo Vault.";
     }
 
     @Override
     public String getWalletExportDescription() {
         return "Export file that can be read by your Cobo Vault using the Multisig Wallet > Import Multisig Wallet feature.";
     }
+
+    @Override
+    public boolean isWalletImportScannable() {
+        return true;
+    }
+
+    @Override
+    public boolean isKeystoreImportScannable() {
+        return true;
+    }
 }

src/main/java/com/sparrowwallet/sparrow/io/CoboVaultSinglesig.java

@@ -1,12 +1,18 @@
 package com.sparrowwallet.sparrow.io;
 
+import com.google.gson.Gson;
+import com.sparrowwallet.drongo.ExtendedKey;
+import com.sparrowwallet.drongo.KeyDerivation;
+import com.sparrowwallet.drongo.policy.Policy;
+import com.sparrowwallet.drongo.policy.PolicyType;
 import com.sparrowwallet.drongo.protocol.ScriptType;
-import com.sparrowwallet.drongo.wallet.Keystore;
-import com.sparrowwallet.drongo.wallet.WalletModel;
+import com.sparrowwallet.drongo.wallet.*;
 
+import java.io.File;
 import java.io.InputStream;
+import java.io.InputStreamReader;
 
-public class CoboVaultSinglesig extends ColdcardSinglesig {
+public class CoboVaultSinglesig implements KeystoreFileImport, WalletImport {
     @Override
     public String getName() {
         return "Cobo Vault";
@@ -14,7 +20,7 @@ public class CoboVaultSinglesig extends ColdcardSinglesig {
 
     @Override
     public String getKeystoreImportDescription() {
-        return "Import file created by using the Watch-Only Wallet > Generic Wallet > Export Wallet feature on your Cobo Vault.";
+        return "Import file or QR created by using the Settings > Watch-Only Wallet > Generic Wallet > Export Wallet feature on your Cobo Vault.";
     }
 
     @Override
@@ -24,10 +30,75 @@ public class CoboVaultSinglesig extends ColdcardSinglesig {
 
     @Override
     public Keystore getKeystore(ScriptType scriptType, InputStream inputStream, String password) throws ImportException {
-        Keystore keystore = super.getKeystore(scriptType, inputStream, password);
-        keystore.setLabel("Cobo Vault");
-        keystore.setWalletModel(getWalletModel());
+        try {
+            Gson gson = new Gson();
+            CoboVaultSinglesigKeystore coboKeystore = gson.fromJson(new InputStreamReader(inputStream), CoboVaultSinglesigKeystore.class);
 
-        return keystore;
+            if(coboKeystore.MasterFingerprint == null || coboKeystore.AccountKeyPath == null || coboKeystore.ExtPubKey == null) {
+                throw new ImportException("Not a valid " + getName() + " keystore export");
+            }
+
+            Keystore keystore = new Keystore();
+            keystore.setLabel(getName());
+            keystore.setSource(KeystoreSource.HW_AIRGAPPED);
+            keystore.setWalletModel(WalletModel.COBO_VAULT);
+            keystore.setKeyDerivation(new KeyDerivation(coboKeystore.MasterFingerprint.toLowerCase(), "m/" + coboKeystore.AccountKeyPath));
+            keystore.setExtendedPublicKey(ExtendedKey.fromDescriptor(coboKeystore.ExtPubKey));
+
+            ExtendedKey.Header header = ExtendedKey.Header.fromExtendedKey(coboKeystore.ExtPubKey);
+            if(header.getDefaultScriptType() != scriptType) {
+                throw new ImportException("This wallet's script type (" + scriptType + ") does not match the " + getName() + " script type (" + header.getDefaultScriptType() + ")");
+            }
+
+            return keystore;
+        } catch (Exception e) {
+            throw new ImportException(e);
+        }
+    }
+
+    @Override
+    public String getWalletImportDescription() {
+        return getKeystoreImportDescription();
+    }
+
+    @Override
+    public Wallet importWallet(InputStream inputStream, String password) throws ImportException {
+        //Use default of P2WPKH
+        Keystore keystore = getKeystore(ScriptType.P2WPKH, inputStream, "");
+
+        Wallet wallet = new Wallet();
+        wallet.setPolicyType(PolicyType.SINGLE);
+        wallet.setScriptType(ScriptType.P2WPKH);
+        wallet.getKeystores().add(keystore);
+        wallet.setDefaultPolicy(Policy.getPolicy(PolicyType.SINGLE, ScriptType.P2WPKH, wallet.getKeystores(), null));
+
+        try {
+            wallet.checkWallet();
+        } catch(InvalidWalletException e) {
+            throw new ImportException("Imported Cobo Vault wallet was invalid: " + e.getMessage());
+        }
+
+        return wallet;
+    }
+
+    @Override
+    public boolean isEncrypted(File file) {
+        return false;
+    }
+
+    @Override
+    public boolean isWalletImportScannable() {
+        return true;
+    }
+
+    @Override
+    public boolean isKeystoreImportScannable() {
+        return true;
+    }
+
+    private static class CoboVaultSinglesigKeystore {
+        public String ExtPubKey;
+        public String MasterFingerprint;
+        public String AccountKeyPath;
     }
 }

src/main/java/com/sparrowwallet/sparrow/io/ColdcardMultisig.java

@@ -37,7 +37,14 @@ public class ColdcardMultisig implements WalletImport, KeystoreFileImport, Walle
         keystore.setSource(KeystoreSource.HW_AIRGAPPED);
         keystore.setWalletModel(WalletModel.COLDCARD);
 
-        if(scriptType.equals(ScriptType.P2SH)) {
+        if(cck.xpub != null && cck.path != null) {
+            ExtendedKey.Header header = ExtendedKey.Header.fromExtendedKey(cck.xpub);
+            if(header.getDefaultScriptType() != scriptType) {
+                throw new ImportException("This wallet's script type (" + scriptType + ") does not match the " + getName() + " script type (" + header.getDefaultScriptType() + ")");
+            }
+            keystore.setKeyDerivation(new KeyDerivation(cck.xfp, cck.path));
+            keystore.setExtendedPublicKey(ExtendedKey.fromDescriptor(cck.xpub));
+        } else if(scriptType.equals(ScriptType.P2SH)) {
             keystore.setKeyDerivation(new KeyDerivation(cck.xfp, cck.p2sh_deriv));
             keystore.setExtendedPublicKey(ExtendedKey.fromDescriptor(cck.p2sh));
         } else if(scriptType.equals(ScriptType.P2SH_P2WSH)) {
@@ -60,6 +67,8 @@ public class ColdcardMultisig implements WalletImport, KeystoreFileImport, Walle
         public String p2wsh_p2sh;
         public String p2wsh_deriv;
         public String p2wsh;
+        public String xpub;
+        public String path;
         public String xfp;
     }
 
@@ -79,7 +88,7 @@ public class ColdcardMultisig implements WalletImport, KeystoreFileImport, Walle
         wallet.setPolicyType(PolicyType.MULTI);
 
         int threshold = 2;
-        ScriptType scriptType = null;
+        ScriptType scriptType = ScriptType.P2SH;
         String derivation = null;
 
         try {
@@ -200,4 +209,14 @@ public class ColdcardMultisig implements WalletImport, KeystoreFileImport, Walle
     public boolean isEncrypted(File file) {
         return false;
     }
+
+    @Override
+    public boolean isWalletImportScannable() {
+        return false;
+    }
+
+    @Override
+    public boolean isKeystoreImportScannable() {
+        return false;
+    }
 }

src/main/java/com/sparrowwallet/sparrow/io/ColdcardSinglesig.java

@@ -8,10 +8,7 @@ import com.sparrowwallet.drongo.KeyDerivation;
 import com.sparrowwallet.drongo.policy.Policy;
 import com.sparrowwallet.drongo.policy.PolicyType;
 import com.sparrowwallet.drongo.protocol.ScriptType;
-import com.sparrowwallet.drongo.wallet.Keystore;
-import com.sparrowwallet.drongo.wallet.KeystoreSource;
-import com.sparrowwallet.drongo.wallet.Wallet;
-import com.sparrowwallet.drongo.wallet.WalletModel;
+import com.sparrowwallet.drongo.wallet.*;
 
 import java.io.File;
 import java.io.InputStream;
@@ -40,6 +37,16 @@ public class ColdcardSinglesig implements KeystoreFileImport, WalletImport {
         return false;
     }
 
+    @Override
+    public boolean isWalletImportScannable() {
+        return false;
+    }
+
+    @Override
+    public boolean isKeystoreImportScannable() {
+        return false;
+    }
+
     @Override
     public Keystore getKeystore(ScriptType scriptType, InputStream inputStream, String password) throws ImportException {
         try {
@@ -62,7 +69,7 @@ public class ColdcardSinglesig implements KeystoreFileImport, WalletImport {
                         ScriptType ckScriptType = ScriptType.valueOf(ck.name.replace("p2wpkh-p2sh", "p2sh_p2wpkh").toUpperCase());
                         if(ckScriptType.equals(scriptType)) {
                             Keystore keystore = new Keystore();
-                            keystore.setLabel("Coldcard");
+                            keystore.setLabel(getName());
                             keystore.setSource(KeystoreSource.HW_AIRGAPPED);
                             keystore.setWalletModel(WalletModel.COLDCARD);
                             keystore.setKeyDerivation(new KeyDerivation(masterFingerprint, ck.deriv));
@@ -96,8 +103,10 @@ public class ColdcardSinglesig implements KeystoreFileImport, WalletImport {
         wallet.getKeystores().add(keystore);
         wallet.setDefaultPolicy(Policy.getPolicy(PolicyType.SINGLE, ScriptType.P2WPKH, wallet.getKeystores(), null));
 
-        if(!wallet.isValid()) {
-            throw new ImportException("Wallet is in an inconsistent state.");
+        try {
+            wallet.checkWallet();
+        } catch(InvalidWalletException e) {
+            throw new ImportException("Imported Coldcard wallet was invalid: " + e.getMessage());
         }
 
         return wallet;

src/main/java/com/sparrowwallet/sparrow/io/Config.java

@@ -4,6 +4,9 @@ import com.google.gson.*;
 import com.sparrowwallet.drongo.BitcoinUnit;
 import com.sparrowwallet.sparrow.Mode;
 import com.sparrowwallet.sparrow.Theme;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
+import com.sparrowwallet.sparrow.net.FeeRatesSource;
+import com.sparrowwallet.sparrow.wallet.FeeRatesSelection;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -19,6 +22,8 @@ public class Config {
 
     private Mode mode;
     private BitcoinUnit bitcoinUnit;
+    private FeeRatesSource feeRatesSource;
+    private FeeRatesSelection feeRatesSelection;
     private Currency fiatCurrency;
     private ExchangeSource exchangeSource;
     private boolean groupByAddress = true;
@@ -98,6 +103,24 @@ public class Config {
         flush();
     }
 
+    public FeeRatesSource getFeeRatesSource() {
+        return feeRatesSource;
+    }
+
+    public void setFeeRatesSource(FeeRatesSource feeRatesSource) {
+        this.feeRatesSource = feeRatesSource;
+        flush();
+    }
+
+    public FeeRatesSelection getFeeRatesSelection() {
+        return feeRatesSelection;
+    }
+
+    public void setFeeRatesSelection(FeeRatesSelection feeRatesSelection) {
+        this.feeRatesSelection = feeRatesSelection;
+        flush();
+    }
+
     public Currency getFiatCurrency() {
         return fiatCurrency;
     }

src/main/java/com/sparrowwallet/sparrow/io/Device.java

@@ -11,6 +11,7 @@ public class Device {
     private Boolean needsPinSent;
     private Boolean needsPassphraseSent;
     private String fingerprint;
+    private String error;
 
     public String getType() {
         return type;
@@ -60,6 +61,14 @@ public class Device {
         this.fingerprint = fingerprint;
     }
 
+    public String getError() {
+        return error;
+    }
+
+    public void setError(String error) {
+        this.error = error;
+    }
+
     public String toString() {
         return getModel() + ":" + getPath();
     }

src/main/java/com/sparrowwallet/sparrow/io/Electrum.java

@@ -138,6 +138,9 @@ public class Electrum implements KeystoreFileImport, WalletImport, WalletExport
                     if(keystore.getWalletModel() == null) {
                         throw new ImportException("Wallet has keystore of unknown hardware wallet type \"" + ek.hw_type + "\".");
                     }
+                    if(keystore.getWalletModel().equals(WalletModel.TREZOR_1)) {
+                        keystore.setWalletModel(WalletModel.TREZOR_T);
+                    }
                 } else if("bip32".equals(ek.type)) {
                     if(ek.xprv != null && ek.seed == null) {
                         throw new ImportException("Electrum does not support exporting BIP39 derived seeds, as it does not store the mnemonic words. Only seeds created with its native Electrum Seed Version System are exportable. " +
@@ -191,15 +194,17 @@ public class Electrum implements KeystoreFileImport, WalletImport, WalletExport
                     if(blockTransaction != null) {
                         blockTransaction.setLabel(ew.labels.get(key));
                     }
-                } catch(IllegalArgumentException e) {
+                } catch(Exception e) {
                     //not a tx, probably an address
                 }
             }
 
             wallet.updateTransactions(ew.transactions);
 
-            if(!wallet.isValid()) {
-                throw new IllegalStateException("Electrum wallet is in an inconsistent state.");
+            try {
+                wallet.checkWallet();
+            } catch(InvalidWalletException e) {
+                throw new IllegalStateException("Imported Electrum wallet was invalid: " + e.getMessage());
             }
 
             return wallet;
@@ -317,6 +322,16 @@ public class Electrum implements KeystoreFileImport, WalletImport, WalletExport
         return (FileType.BINARY.equals(IOUtils.getFileType(file)));
     }
 
+    @Override
+    public boolean isWalletImportScannable() {
+        return false;
+    }
+
+    @Override
+    public boolean isKeystoreImportScannable() {
+        return false;
+    }
+
     @Override
     public String getWalletExportDescription() {
         return "Export this wallet as an Electrum wallet file.";

src/main/java/com/sparrowwallet/sparrow/io/Hwi.java

@@ -29,7 +29,7 @@ import java.util.zip.ZipInputStream;
 
 public class Hwi {
     private static final Logger log = LoggerFactory.getLogger(Hwi.class);
-    private static final String TEMP_FILE_PREFIX = "hwi-1.1.2-";
+    private static final String TEMP_FILE_PREFIX = "hwi-1.2.1-";
 
     private static boolean isPromptActive = false;
 
@@ -84,7 +84,7 @@ public class Hwi {
             if(result.get("xpub") != null) {
                 return result.get("xpub").getAsString();
             } else {
-                throw new ImportException("Could not retrieve xpub");
+                throw new ImportException("Could not retrieve xpub - reconnect your device and try again.");
             }
         } catch(IOException e) {
             throw new ImportException(e);
@@ -218,7 +218,7 @@ public class Hwi {
                 //The check will still happen on first invocation, but will not thereafter
                 //See https://github.com/bitcoin-core/HWI/issues/327 for details
                 if(platform == Platform.OSX) {
-                    InputStream inputStream = Hwi.class.getResourceAsStream("/native/osx/x64/hwi-1.1.2-mac-amd64-signed.zip");
+                    InputStream inputStream = Hwi.class.getResourceAsStream("/native/osx/x64/hwi-1.2.1-mac-amd64-signed.zip");
                     Path tempHwiDirPath = Files.createTempDirectory(TEMP_FILE_PREFIX, PosixFilePermissions.asFileAttribute(ownerExecutableWritable));
                     File tempHwiDir = tempHwiDirPath.toFile();
                     //tempHwiDir.deleteOnExit();
@@ -535,7 +535,17 @@ public class Hwi {
     private static class DeviceModelDeserializer implements JsonDeserializer<WalletModel> {
         @Override
         public WalletModel deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
-            return WalletModel.valueOf(json.getAsJsonPrimitive().getAsString().toUpperCase());
+            String modelStr = json.getAsJsonPrimitive().getAsString();
+            try {
+                return WalletModel.valueOf(modelStr.toUpperCase());
+            } catch(Exception e) {
+                for(WalletModel model : WalletModel.values()) {
+                    if(modelStr.startsWith(model.getType())) {
+                        return model;
+                    }
+                }
+            }
+            throw new IllegalArgumentException("Could not determine wallet model for " + modelStr);
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/io/KeystoreFileImport.java

@@ -3,9 +3,9 @@ package com.sparrowwallet.sparrow.io;
 import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.wallet.Keystore;
 
-import java.io.File;
 import java.io.InputStream;
 
 public interface KeystoreFileImport extends KeystoreImport, FileImport {
     Keystore getKeystore(ScriptType scriptType, InputStream inputStream, String password) throws ImportException;
+    boolean isKeystoreImportScannable();
 }

src/main/java/com/sparrowwallet/sparrow/io/Specter.java

@@ -3,6 +3,7 @@ package com.sparrowwallet.sparrow.io;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.sparrowwallet.drongo.OutputDescriptor;
+import com.sparrowwallet.drongo.wallet.InvalidWalletException;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.drongo.wallet.WalletModel;
 
@@ -57,8 +58,10 @@ public class Specter implements WalletImport, WalletExport {
                 Wallet wallet = outputDescriptor.toWallet();
                 wallet.setName(specterWallet.label);
 
-                if(!wallet.isValid()) {
-                    throw new ImportException("Specter wallet file did not contain a valid wallet");
+                try {
+                    wallet.checkWallet();
+                } catch(InvalidWalletException e) {
+                    throw new ImportException("Imported Specter wallet was invalid: " + e.getMessage());
                 }
 
                 return wallet;
@@ -75,6 +78,11 @@ public class Specter implements WalletImport, WalletExport {
         return false;
     }
 
+    @Override
+    public boolean isWalletImportScannable() {
+        return true;
+    }
+
     @Override
     public String getName() {
         return "Specter";

src/main/java/com/sparrowwallet/sparrow/io/Storage.java

@@ -254,6 +254,19 @@ public class Storage {
         return (encrypted.exists() || unencrypted.exists());
     }
 
+    public static File getExistingWallet(String walletName) {
+        File encrypted = new File(getWalletsDir(), walletName);
+        File unencrypted = new File(getWalletsDir(), walletName + ".json");
+
+        if(encrypted.exists()) {
+            return encrypted;
+        } else if(unencrypted.exists()) {
+            return unencrypted;
+        }
+
+        return null;
+    }
+
     public static File getWalletFile(String walletName) {
         //TODO: Check for existing file
         return new File(getWalletsDir(), walletName);
@@ -285,7 +298,7 @@ public class Storage {
         return getSparrowHome();
     }
 
-    static File getSparrowHome() {
+    public static File getSparrowHome() {
         if(System.getProperty(MainApp.APP_HOME_PROPERTY) != null) {
             return new File(System.getProperty(MainApp.APP_HOME_PROPERTY));
         }

src/main/java/com/sparrowwallet/sparrow/io/WalletImport.java

@@ -2,10 +2,10 @@ package com.sparrowwallet.sparrow.io;
 
 import com.sparrowwallet.drongo.wallet.Wallet;
 
-import java.io.File;
 import java.io.InputStream;
 
 public interface WalletImport extends Import, FileImport {
     String getWalletImportDescription();
     Wallet importWallet(InputStream inputStream, String password) throws ImportException;
+    boolean isWalletImportScannable();
 }

src/main/java/com/sparrowwallet/sparrow/net/BatchedElectrumServerRpc.java

@@ -6,6 +6,7 @@ import com.github.arteam.simplejsonrpc.client.builder.BatchRequestBuilder;
 import com.github.arteam.simplejsonrpc.client.exception.JsonRpcBatchException;
 import com.github.arteam.simplejsonrpc.client.exception.JsonRpcException;
 import com.sparrowwallet.drongo.protocol.Sha256Hash;
+import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.WalletHistoryStatusEvent;
 import org.slf4j.Logger;
@@ -14,10 +15,13 @@ import org.slf4j.LoggerFactory;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.concurrent.atomic.AtomicLong;
 
 public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     private static final Logger log = LoggerFactory.getLogger(BatchedElectrumServerRpc.class);
+    private static final int MAX_RETRIES = 3;
+    private static final int RETRY_DELAY = 0;
 
     private final AtomicLong idCounter = new AtomicLong();
 
@@ -25,8 +29,9 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public void ping(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            client.createRequest().method("server.ping").id(idCounter.incrementAndGet()).executeNullable();
-        } catch(JsonRpcException e) {
+            new RetryLogic<>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().method("server.ping").id(idCounter.incrementAndGet()).executeNullable());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error pinging server", e);
         }
     }
@@ -35,8 +40,9 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public List<String> getServerVersion(Transport transport, String clientName, String[] supportedVersions) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAsList(String.class).method("server.version").id(idCounter.incrementAndGet()).param("client_name", clientName).param("protocol_version", supportedVersions).execute();
-        } catch(JsonRpcException e) {
+            return new RetryLogic<List<String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAsList(String.class).method("server.version").id(idCounter.incrementAndGet()).param("client_name", clientName).param("protocol_version", supportedVersions).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting server version", e);
         }
     }
@@ -45,8 +51,9 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public String getServerBanner(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(String.class).method("server.banner").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException e) {
+            return new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(String.class).method("server.banner").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting server banner", e);
         }
     }
@@ -55,25 +62,26 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public BlockHeaderTip subscribeBlockHeaders(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(BlockHeaderTip.class).method("blockchain.headers.subscribe").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException e) {
+            return new RetryLogic<BlockHeaderTip>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(BlockHeaderTip.class).method("blockchain.headers.subscribe").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error subscribing to block headers", e);
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError) {
+    public Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError) {
         JsonRpcClient client = new JsonRpcClient(transport);
         BatchRequestBuilder<String, ScriptHashTx[]> batchRequest = client.createBatchRequest().keysType(String.class).returnType(ScriptHashTx[].class);
-        EventManager.get().post(new WalletHistoryStatusEvent(false, "Loading transactions"));
+        EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Loading transactions"));
 
         for(String path : pathScriptHashes.keySet()) {
             batchRequest.add(path, "blockchain.scripthash.get_history", pathScriptHashes.get(path));
         }
 
         try {
-            return batchRequest.execute();
+            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
         } catch (JsonRpcBatchException e) {
             if(failOnError) {
                 throw new ElectrumServerRpcException("Failed to retrieve references for paths: " + e.getErrors().keySet(), e);
@@ -85,12 +93,14 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
             }
 
             return result;
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to retrieve references for paths: " + pathScriptHashes.keySet(), e);
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError) {
+    public Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError) {
         JsonRpcClient client = new JsonRpcClient(transport);
         BatchRequestBuilder<String, ScriptHashTx[]> batchRequest = client.createBatchRequest().keysType(String.class).returnType(ScriptHashTx[].class);
 
@@ -99,8 +109,8 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return batchRequest.execute();
-        } catch (JsonRpcBatchException e) {
+            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+        } catch(JsonRpcBatchException e) {
             if(failOnError) {
                 throw new ElectrumServerRpcException("Failed to retrieve references for paths: " + e.getErrors().keySet(), e);
             }
@@ -111,59 +121,65 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
             }
 
             return result;
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to retrieve references for paths: " + pathScriptHashes.keySet(), e);
         }
     }
 
     @Override
-    public Map<String, String> subscribeScriptHashes(Transport transport, Map<String, String> pathScriptHashes) {
+    public Map<String, String> subscribeScriptHashes(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes) {
         JsonRpcClient client = new JsonRpcClient(transport);
         BatchRequestBuilder<String, String> batchRequest = client.createBatchRequest().keysType(String.class).returnType(String.class);
-        EventManager.get().post(new WalletHistoryStatusEvent(false, "Finding transactions"));
+        EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Finding transactions"));
 
         for(String path : pathScriptHashes.keySet()) {
             batchRequest.add(path, "blockchain.scripthash.subscribe", pathScriptHashes.get(path));
         }
 
         try {
-            return batchRequest.execute();
+            return new RetryLogic<Map<String, String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
         } catch(JsonRpcBatchException e) {
             //Even if we have some successes, failure to subscribe for all script hashes will result in outdated wallet view. Don't proceed.
             throw new ElectrumServerRpcException("Failed to subscribe for updates for paths: " + e.getErrors().keySet(), e);
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to subscribe for updates for paths: " + pathScriptHashes.keySet(), e);
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Map<Integer, String> getBlockHeaders(Transport transport, Set<Integer> blockHeights) {
+    public Map<Integer, String> getBlockHeaders(Transport transport, Wallet wallet, Set<Integer> blockHeights) {
         JsonRpcClient client = new JsonRpcClient(transport);
         BatchRequestBuilder<Integer, String> batchRequest = client.createBatchRequest().keysType(Integer.class).returnType(String.class);
-        EventManager.get().post(new WalletHistoryStatusEvent(false, "Retrieving blocks"));
+        EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Retrieving blocks"));
 
         for(Integer height : blockHeights) {
             batchRequest.add(height, "blockchain.block.header", height);
         }
 
         try {
-            return batchRequest.execute();
-        } catch (JsonRpcBatchException e) {
+            return new RetryLogic<Map<Integer, String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+        } catch(JsonRpcBatchException e) {
             return (Map<Integer, String>)e.getSuccesses();
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to block headers for block heights: " + blockHeights, e);
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
-    public Map<String, String> getTransactions(Transport transport, Set<String> txids) {
+    public Map<String, String> getTransactions(Transport transport, Wallet wallet, Set<String> txids) {
         JsonRpcClient client = new JsonRpcClient(transport);
         BatchRequestBuilder<String, String> batchRequest = client.createBatchRequest().keysType(String.class).returnType(String.class);
-        EventManager.get().post(new WalletHistoryStatusEvent(false, "Retrieving transactions"));
+        EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Retrieving transactions"));
 
         for(String txid : txids) {
             batchRequest.add(txid, "blockchain.transaction.get", txid);
         }
 
         try {
-            return batchRequest.execute();
-        } catch (JsonRpcBatchException e) {
+            return new RetryLogic<Map<String, String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+        } catch(JsonRpcBatchException e) {
             Map<String, String> result = (Map<String, String>)e.getSuccesses();
 
             String strErrorTx = Sha256Hash.ZERO_HASH.toString();
@@ -173,6 +189,8 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
             }
 
             return result;
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to retrieve transactions for txids: " + txids, e);
         }
     }
 
@@ -186,10 +204,12 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return batchRequest.execute();
-        } catch (JsonRpcBatchException e) {
+            return new RetryLogic<Map<String, VerboseTransaction>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+        } catch(JsonRpcBatchException e) {
             log.warn("Some errors retrieving transactions: " + e.getErrors());
             return (Map<String, VerboseTransaction>)e.getSuccesses();
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Failed to retrieve verbose transactions for txids: " + txids, e);
         }
     }
 
@@ -202,9 +222,29 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return batchRequest.execute();
+            return new RetryLogic<Map<Integer, Double>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
         } catch(JsonRpcBatchException e) {
             throw new ElectrumServerRpcException("Error getting fee estimates", e);
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Error getting fee estimates for target blocks: " + targetBlocks, e);
+        }
+    }
+
+    @Override
+    public Map<Long, Long> getFeeRateHistogram(Transport transport) {
+        try {
+            JsonRpcClient client = new JsonRpcClient(transport);
+            Long[][] feesArray = new RetryLogic<Long[][]>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(Long[][].class).method("mempool.get_fee_histogram").id(idCounter.incrementAndGet()).execute());
+
+            Map<Long, Long> feeRateHistogram = new TreeMap<>();
+            for(Long[] feePair : feesArray) {
+                feeRateHistogram.put(feePair[0], feePair[1]);
+            }
+
+            return feeRateHistogram;
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Error getting fee rate histogram", e);
         }
     }
 
@@ -212,8 +252,9 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public Double getMinimumRelayFee(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(Double.class).method("blockchain.relayfee").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException e) {
+            return new RetryLogic<Double>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(Double.class).method("blockchain.relayfee").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting minimum relay fee", e);
         }
     }
@@ -222,9 +263,12 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     public String broadcastTransaction(Transport transport, String txHex) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(String.class).method("blockchain.transaction.broadcast").id(idCounter.incrementAndGet()).param("raw_tx", txHex).execute();
+            return new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(String.class).method("blockchain.transaction.broadcast").id(idCounter.incrementAndGet()).param("raw_tx", txHex).execute());
         } catch(JsonRpcException e) {
             throw new ElectrumServerRpcException(e.getErrorMessage().getMessage(), e);
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Error broadcasting transaction", e);
         }
     }
 }

src/main/java/com/sparrowwallet/sparrow/net/ElectrumServer.java

@@ -5,6 +5,7 @@ import com.google.common.collect.Iterables;
 import com.google.common.eventbus.Subscribe;
 import com.google.common.net.HostAndPort;
 import com.sparrowwallet.drongo.KeyPurpose;
+import com.sparrowwallet.drongo.Network;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.protocol.*;
 import com.sparrowwallet.drongo.wallet.*;
@@ -137,15 +138,65 @@ public class ElectrumServer {
 
     public Map<WalletNode, Set<BlockTransactionHash>> getHistory(Wallet wallet, Collection<WalletNode> nodes) throws ServerException {
         Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap = new TreeMap<>();
-        subscribeWalletNodes(wallet, nodes, nodeTransactionMap, 0);
-        getReferences(wallet, nodes, nodeTransactionMap);
+
+        Set<WalletNode> historyNodes = new HashSet<>(nodes);
+        //Add any nodes with mempool transactions in case these have been replaced
+        Set<WalletNode> mempoolNodes = wallet.getWalletTxos().entrySet().stream()
+                .filter(entry -> entry.getKey().getHeight() <= 0 || (entry.getKey().getSpentBy() != null && entry.getKey().getSpentBy().getHeight() <= 0))
+                .map(Map.Entry::getValue)
+                .collect(Collectors.toSet());
+        historyNodes.addAll(mempoolNodes);
+
+        subscribeWalletNodes(wallet, historyNodes, nodeTransactionMap, 0);
+        getReferences(wallet, nodeTransactionMap.keySet(), nodeTransactionMap, 0);
+        Set<BlockTransactionHash> newReferences = nodeTransactionMap.values().stream().flatMap(Collection::stream).filter(ref -> !wallet.getTransactions().containsKey(ref.getHash())).collect(Collectors.toSet());
+        getReferencedTransactions(wallet, nodeTransactionMap);
+
+        if(!newReferences.isEmpty()) {
+            //Look for additional nodes to fetch history for by considering the inputs and outputs of new transactions found
+            log.debug("Found new transactions: " + newReferences);
+            Set<WalletNode> additionalNodes = new HashSet<>();
+            Map<String, WalletNode> walletScriptHashes = getAllScriptHashes(wallet);
+            for(BlockTransactionHash reference : newReferences) {
+                BlockTransaction blockTransaction = wallet.getTransactions().get(reference.getHash());
+                for(TransactionOutput txOutput : blockTransaction.getTransaction().getOutputs()) {
+                    WalletNode node = walletScriptHashes.get(getScriptHash(txOutput));
+                    if(node != null && !historyNodes.contains(node)) {
+                        additionalNodes.add(node);
+                    }
+                }
+
+                for(TransactionInput txInput : blockTransaction.getTransaction().getInputs()) {
+                    BlockTransaction inputBlockTransaction = wallet.getTransactions().get(txInput.getOutpoint().getHash());
+                    if(inputBlockTransaction != null) {
+                        TransactionOutput txOutput = inputBlockTransaction.getTransaction().getOutputs().get((int)txInput.getOutpoint().getIndex());
+                        WalletNode node = walletScriptHashes.get(getScriptHash(txOutput));
+                        if(node != null && !historyNodes.contains(node)) {
+                            additionalNodes.add(node);
+                        }
+                    }
+                }
+            }
+
+            if(!additionalNodes.isEmpty()) {
+                log.debug("Found additional nodes: " + additionalNodes);
+                subscribeWalletNodes(wallet, additionalNodes, nodeTransactionMap, 0);
+                getReferences(wallet, additionalNodes, nodeTransactionMap, 0);
+                getReferencedTransactions(wallet, nodeTransactionMap);
+            }
+        }
 
         return nodeTransactionMap;
     }
 
     public void getHistory(Wallet wallet, KeyPurpose keyPurpose, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) throws ServerException {
         WalletNode purposeNode = wallet.getNode(keyPurpose);
+        //Subscribe to all existing address WalletNodes and add them to nodeTransactionMap as keys to empty sets if they have history
         subscribeWalletNodes(wallet, purposeNode.getChildren(), nodeTransactionMap, 0);
+        //All WalletNode keys in nodeTransactionMap need to have their history fetched (nodes without history will not be keys in the map yet)
+        getReferences(wallet, nodeTransactionMap.keySet(), nodeTransactionMap, 0);
+        //Fetch all referenced transaction to wallet transactions map. We do this now even though it is done again later to get it done before too many script hashes are subscribed
+        getReferencedTransactions(wallet, nodeTransactionMap);
 
         //Because node children are added sequentially in WalletNode.fillToIndex, we can simply look at the number of children to determine the highest filled index
         int historySize = purposeNode.getChildren().size();
@@ -154,29 +205,28 @@ public class ElectrumServer {
         while(historySize < gapLimitSize) {
             purposeNode.fillToIndex(gapLimitSize - 1);
             subscribeWalletNodes(wallet, purposeNode.getChildren(), nodeTransactionMap, historySize);
+            getReferences(wallet, nodeTransactionMap.keySet(), nodeTransactionMap, historySize);
+            getReferencedTransactions(wallet, nodeTransactionMap);
             historySize = purposeNode.getChildren().size();
             gapLimitSize = getGapLimitSize(wallet, nodeTransactionMap);
         }
 
-        //All WalletNode keys in nodeTransactionMap with non-null values need to have their history fetched
-        Collection<WalletNode> usedNodes = nodeTransactionMap.entrySet().stream().filter(entry -> entry.getValue() != null).map(Map.Entry::getKey).collect(Collectors.toList());
-        log.debug("Retrieving history for " + usedNodes.stream().map(WalletNode::getDerivationPath).collect(Collectors.joining(", ")));
-        getReferences(wallet, usedNodes, nodeTransactionMap);
-
-        //Set the remaining WalletNode keys to empty sets to indicate no history
-        nodeTransactionMap.entrySet().stream().filter(entry -> entry.getValue() == null).forEach(entry -> entry.setValue(Collections.emptySet()));
+        //Set the remaining WalletNode keys in nodeTransactionMap to empty sets to indicate no history
+        purposeNode.getChildren().stream().filter(node -> !nodeTransactionMap.containsKey(node)).forEach(node -> nodeTransactionMap.put(node, Collections.emptySet()));
     }
 
     private int getGapLimitSize(Wallet wallet, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) {
-        int highestIndex = nodeTransactionMap.entrySet().stream().filter(entry -> !entry.getValue().isEmpty()).map(entry -> entry.getKey().getIndex()).max(Comparator.comparing(Integer::valueOf)).orElse(-1);
+        int highestIndex = nodeTransactionMap.keySet().stream().map(WalletNode::getIndex).max(Comparator.comparing(Integer::valueOf)).orElse(-1);
         return highestIndex + wallet.getGapLimit() + 1;
     }
 
-    public void getReferences(Wallet wallet, Collection<WalletNode> nodes, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) throws ServerException {
+    public void getReferences(Wallet wallet, Collection<WalletNode> nodes, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap, int startIndex) throws ServerException {
         try {
             Map<String, String> pathScriptHashes = new LinkedHashMap<>(nodes.size());
             for(WalletNode node : nodes) {
-                pathScriptHashes.put(node.getDerivationPath(), getScriptHash(wallet, node));
+                if(node.getIndex() >= startIndex) {
+                    pathScriptHashes.put(node.getDerivationPath(), getScriptHash(wallet, node));
+                }
             }
 
             if(pathScriptHashes.isEmpty()) {
@@ -184,7 +234,7 @@ public class ElectrumServer {
             }
 
             //Even if we have some successes, failure to retrieve all references will result in an incomplete wallet history. Don't proceed if that's the case.
-            Map<String, ScriptHashTx[]> result = electrumServerRpc.getScriptHashHistory(getTransport(), pathScriptHashes, true);
+            Map<String, ScriptHashTx[]> result = electrumServerRpc.getScriptHashHistory(getTransport(), wallet, pathScriptHashes, true);
 
             for(String path : result.keySet()) {
                 ScriptHashTx[] txes = result.get(path);
@@ -193,7 +243,19 @@ public class ElectrumServer {
                 if(optionalNode.isPresent()) {
                     WalletNode node = optionalNode.get();
 
-                    Set<BlockTransactionHash> references = Arrays.stream(txes).map(ScriptHashTx::getBlockchainTransactionHash).collect(Collectors.toCollection(TreeSet::new));
+                    //Some servers can return the same tx as multiple ScriptHashTx entries with different heights. Take the highest height only
+                    Set<BlockTransactionHash> references = Arrays.stream(txes).map(ScriptHashTx::getBlockchainTransactionHash)
+                            .collect(TreeSet::new, (set, ref) -> {
+                                Optional<BlockTransactionHash> optExisting = set.stream().filter(prev -> prev.getHash().equals(ref.getHash())).findFirst();
+                                if(optExisting.isPresent()) {
+                                    if(optExisting.get().getHeight() < ref.getHeight()) {
+                                        set.remove(optExisting.get());
+                                        set.add(ref);
+                                    }
+                                } else {
+                                    set.add(ref);
+                                }
+                            }, TreeSet::addAll);
                     Set<BlockTransactionHash> existingReferences = nodeTransactionMap.get(node);
 
                     if(existingReferences == null) {
@@ -226,7 +288,11 @@ public class ElectrumServer {
             Set<String> scriptHashes = new HashSet<>();
             Map<String, String> pathScriptHashes = new LinkedHashMap<>();
             for(WalletNode node : nodes) {
-                if(node.getIndex() >= startIndex) {
+                if(node == null) {
+                    log.error("Null node for wallet " + wallet.getName() + " subscribing nodes " + nodes + " startIndex " + startIndex, new Throwable());
+                }
+
+                if(node != null && node.getIndex() >= startIndex) {
                     String scriptHash = getScriptHash(wallet, node);
                     if(getSubscribedScriptHashStatus(scriptHash) != null) {
                         //Already subscribed, but still need to fetch history from a used node
@@ -242,7 +308,7 @@ public class ElectrumServer {
                 return;
             }
 
-            Map<String, String> result = electrumServerRpc.subscribeScriptHashes(getTransport(), pathScriptHashes);
+            Map<String, String> result = electrumServerRpc.subscribeScriptHashes(getTransport(), wallet, pathScriptHashes);
 
             for(String path : result.keySet()) {
                 String status = result.get(path);
@@ -276,7 +342,7 @@ public class ElectrumServer {
                 pathScriptHashes.put(Integer.toString(i), getScriptHash(output));
             }
 
-            Map<String, ScriptHashTx[]> result = electrumServerRpc.getScriptHashHistory(getTransport(), pathScriptHashes, false);
+            Map<String, ScriptHashTx[]> result = electrumServerRpc.getScriptHashHistory(getTransport(), null, pathScriptHashes, false);
 
             List<Set<BlockTransactionHash>> blockTransactionHashes = new ArrayList<>(transaction.getOutputs().size());
             for(int i = 0; i < transaction.getOutputs().size(); i++) {
@@ -318,10 +384,18 @@ public class ElectrumServer {
             references.addAll(nodeReferences);
         }
 
+        for(Iterator<BlockTransactionHash> iter = references.iterator(); iter.hasNext(); ) {
+            BlockTransactionHash reference = iter.next();
+            BlockTransaction blockTransaction = wallet.getTransactions().get(reference.getHash());
+            if(blockTransaction != null && reference.getHeight() == blockTransaction.getHeight()) {
+                iter.remove();
+            }
+        }
+
         Map<Sha256Hash, BlockTransaction> transactionMap = new HashMap<>();
         if(!references.isEmpty()) {
-            Map<Integer, BlockHeader> blockHeaderMap = getBlockHeaders(references);
-            transactionMap = getTransactions(references, blockHeaderMap);
+            Map<Integer, BlockHeader> blockHeaderMap = getBlockHeaders(wallet, references);
+            transactionMap = getTransactions(wallet, references, blockHeaderMap);
         }
 
         if(!transactionMap.equals(wallet.getTransactions())) {
@@ -329,7 +403,7 @@ public class ElectrumServer {
         }
     }
 
-    public Map<Integer, BlockHeader> getBlockHeaders(Set<BlockTransactionHash> references) throws ServerException {
+    public Map<Integer, BlockHeader> getBlockHeaders(Wallet wallet, Set<BlockTransactionHash> references) throws ServerException {
         try {
             Set<Integer> blockHeights = new TreeSet<>();
             for(BlockTransactionHash reference : references) {
@@ -342,7 +416,7 @@ public class ElectrumServer {
                 return Collections.emptyMap();
             }
 
-            Map<Integer, String> result = electrumServerRpc.getBlockHeaders(getTransport(), blockHeights);
+            Map<Integer, String> result = electrumServerRpc.getBlockHeaders(getTransport(), wallet, blockHeights);
 
             Map<Integer, BlockHeader> blockHeaderMap = new TreeMap<>();
             for(Integer height : result.keySet()) {
@@ -364,7 +438,7 @@ public class ElectrumServer {
         }
     }
 
-    public Map<Sha256Hash, BlockTransaction> getTransactions(Set<BlockTransactionHash> references, Map<Integer, BlockHeader> blockHeaderMap) throws ServerException {
+    public Map<Sha256Hash, BlockTransaction> getTransactions(Wallet wallet, Set<BlockTransactionHash> references, Map<Integer, BlockHeader> blockHeaderMap) throws ServerException {
         try {
             Set<BlockTransactionHash> checkReferences = new TreeSet<>(references);
 
@@ -373,7 +447,7 @@ public class ElectrumServer {
                 txids.add(reference.getHashAsString());
             }
 
-            Map<String, String> result = electrumServerRpc.getTransactions(getTransport(), txids);
+            Map<String, String> result = electrumServerRpc.getTransactions(getTransport(), wallet, txids);
 
             String strErrorTx = Sha256Hash.ZERO_HASH.toString();
             Map<Sha256Hash, BlockTransaction> transactionMap = new HashMap<>();
@@ -388,7 +462,14 @@ public class ElectrumServer {
                 }
 
                 byte[] rawtx = Utils.hexToBytes(strRawTx);
-                Transaction transaction = new Transaction(rawtx);
+                Transaction transaction;
+
+                try {
+                    transaction = new Transaction(rawtx);
+                } catch(ProtocolException e) {
+                    log.error("Could not parse tx: " + strRawTx);
+                    continue;
+                }
 
                 Optional<BlockTransactionHash> optionalReference = references.stream().filter(reference -> reference.getHash().equals(hash)).findFirst();
                 if(optionalReference.isEmpty()) {
@@ -439,7 +520,9 @@ public class ElectrumServer {
         Set<BlockTransactionHash> history = nodeTransactionMap.get(node);
         for(BlockTransactionHash reference : history) {
             BlockTransaction blockTransaction = wallet.getTransactions().get(reference.getHash());
-            if(blockTransaction == null || blockTransaction.equals(UNFETCHABLE_BLOCK_TRANSACTION)) {
+            if(blockTransaction == null) {
+                throw new IllegalStateException("Did not retrieve transaction for hash " + reference.getHashAsString());
+            } else if(blockTransaction.equals(UNFETCHABLE_BLOCK_TRANSACTION)) {
                 throw new IllegalStateException("Could not retrieve transaction for hash " + reference.getHashAsString());
             }
             Transaction transaction = blockTransaction.getTransaction();
@@ -531,12 +614,28 @@ public class ElectrumServer {
                 targetBlocksFeeRatesSats.put(target, minFeeRateSatsKb / 1000d);
             }
 
+            FeeRatesSource feeRatesSource = Config.get().getFeeRatesSource();
+            feeRatesSource = (feeRatesSource == null ? FeeRatesSource.MEMPOOL_SPACE : feeRatesSource);
+            if(Network.get().equals(Network.MAINNET)) {
+                targetBlocksFeeRatesSats.putAll(feeRatesSource.getBlockTargetFeeRates(targetBlocksFeeRatesSats));
+            }
+
             return targetBlocksFeeRatesSats;
         } catch(ElectrumServerRpcException e) {
             throw new ServerException(e.getMessage(), e);
         }
     }
 
+    public Set<MempoolRateSize> getMempoolRateSizes() throws ServerException {
+        Map<Long, Long> feeRateHistogram = electrumServerRpc.getFeeRateHistogram(getTransport());
+        Set<MempoolRateSize> mempoolRateSizes = new TreeSet<>();
+        for(Long fee : feeRateHistogram.keySet()) {
+            mempoolRateSizes.add(new MempoolRateSize(fee, feeRateHistogram.get(fee)));
+        }
+
+        return mempoolRateSizes;
+    }
+
     public Double getMinimumRelayFee() throws ServerException {
         Double minFeeRateBtcKb = electrumServerRpc.getMinimumRelayFee(getTransport());
         if(minFeeRateBtcKb != null) {
@@ -564,6 +663,18 @@ public class ElectrumServer {
         }
     }
 
+    public static Map<String, WalletNode> getAllScriptHashes(Wallet wallet) {
+        Map<String, WalletNode> scriptHashes = new HashMap<>();
+        List<KeyPurpose> purposes = List.of(KeyPurpose.RECEIVE, KeyPurpose.CHANGE);
+        for(KeyPurpose keyPurpose : purposes) {
+            for(WalletNode childNode : wallet.getNode(keyPurpose).getChildren()) {
+                scriptHashes.put(getScriptHash(wallet, childNode), childNode);
+            }
+        }
+
+        return scriptHashes;
+    }
+
     public static String getScriptHash(Wallet wallet, WalletNode node) {
         byte[] hash = Sha256Hash.hash(wallet.getOutputScript(node).getProgram());
         byte[] reversed = Utils.reverseBytes(hash);
@@ -623,7 +734,7 @@ public class ElectrumServer {
     }
 
     public static class ConnectionService extends ScheduledService<FeeRatesUpdatedEvent> implements Thread.UncaughtExceptionHandler {
-        private static final int FEE_RATES_PERIOD = 5 * 60 * 1000;
+        private static final int FEE_RATES_PERIOD = 30 * 1000;
 
         private final boolean subscribe;
         private boolean firstCall = true;
@@ -675,6 +786,7 @@ public class ElectrumServer {
                         String banner = electrumServer.getServerBanner();
 
                         Map<Integer, Double> blockTargetFeeRates = electrumServer.getFeeEstimates(SendController.TARGET_BLOCKS_RANGE);
+                        Set<MempoolRateSize> mempoolRateSizes = electrumServer.getMempoolRateSizes();
                         feeRatesRetrievedAt = System.currentTimeMillis();
 
                         Double minimumRelayFeeRate = electrumServer.getMinimumRelayFee();
@@ -682,7 +794,7 @@ public class ElectrumServer {
                             blockTargetFeeRates.computeIfPresent(blockTarget, (blocks, feeRate) -> feeRate < minimumRelayFeeRate ? minimumRelayFeeRate : feeRate);
                         }
 
-                        return new ConnectionEvent(serverVersion, banner, tip.height, tip.getBlockHeader(), blockTargetFeeRates, minimumRelayFeeRate);
+                        return new ConnectionEvent(serverVersion, banner, tip.height, tip.getBlockHeader(), blockTargetFeeRates, mempoolRateSizes, minimumRelayFeeRate);
                     } else {
                         if(reader.isAlive()) {
                             electrumServer.ping();
@@ -690,8 +802,9 @@ public class ElectrumServer {
                             long elapsed = System.currentTimeMillis() - feeRatesRetrievedAt;
                             if(elapsed > FEE_RATES_PERIOD) {
                                 Map<Integer, Double> blockTargetFeeRates = electrumServer.getFeeEstimates(SendController.TARGET_BLOCKS_RANGE);
+                                Set<MempoolRateSize> mempoolRateSizes = electrumServer.getMempoolRateSizes();
                                 feeRatesRetrievedAt = System.currentTimeMillis();
-                                return new FeeRatesUpdatedEvent(blockTargetFeeRates);
+                                return new FeeRatesUpdatedEvent(blockTargetFeeRates, mempoolRateSizes);
                             }
                         } else {
                             resetConnection();
@@ -760,6 +873,7 @@ public class ElectrumServer {
     public static class TransactionHistoryService extends Service<Boolean> {
         private final Wallet wallet;
         private final Set<WalletNode> nodes;
+        private final static Map<Wallet, Object> walletSynchronizeLocks = new HashMap<>();
 
         public TransactionHistoryService(Wallet wallet) {
             this.wallet = wallet;
@@ -775,11 +889,14 @@ public class ElectrumServer {
         protected Task<Boolean> createTask() {
             return new Task<>() {
                 protected Boolean call() throws ServerException {
-                    ElectrumServer electrumServer = new ElectrumServer();
-                    Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap = (nodes == null ? electrumServer.getHistory(wallet) : electrumServer.getHistory(wallet, nodes));
-                    electrumServer.getReferencedTransactions(wallet, nodeTransactionMap);
-                    electrumServer.calculateNodeHistory(wallet, nodeTransactionMap);
-                    return true;
+                    walletSynchronizeLocks.putIfAbsent(wallet, new Object());
+                    synchronized(walletSynchronizeLocks.get(wallet)) {
+                        ElectrumServer electrumServer = new ElectrumServer();
+                        Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap = (nodes == null ? electrumServer.getHistory(wallet) : electrumServer.getHistory(wallet, nodes));
+                        electrumServer.getReferencedTransactions(wallet, nodeTransactionMap);
+                        electrumServer.calculateNodeHistory(wallet, nodeTransactionMap);
+                        return true;
+                    }
                 }
             };
         }
@@ -857,8 +974,8 @@ public class ElectrumServer {
 
                     Map<Sha256Hash, BlockTransaction> transactionMap = new HashMap<>();
                     if(!setReferences.isEmpty()) {
-                        Map<Integer, BlockHeader> blockHeaderMap = electrumServer.getBlockHeaders(setReferences);
-                        transactionMap = electrumServer.getTransactions(setReferences, blockHeaderMap);
+                        Map<Integer, BlockHeader> blockHeaderMap = electrumServer.getBlockHeaders(null, setReferences);
+                        transactionMap = electrumServer.getTransactions(null, setReferences, blockHeaderMap);
                     }
 
                     for(int i = 0; i < outputTransactionReferences.size(); i++) {
@@ -913,4 +1030,18 @@ public class ElectrumServer {
             };
         }
     }
+
+    public static class FeeRatesService extends Service<FeeRatesUpdatedEvent> {
+        @Override
+        protected Task<FeeRatesUpdatedEvent> createTask() {
+            return new Task<>() {
+                protected FeeRatesUpdatedEvent call() throws ServerException {
+                    ElectrumServer electrumServer = new ElectrumServer();
+                    Map<Integer, Double> blockTargetFeeRates = electrumServer.getFeeEstimates(SendController.TARGET_BLOCKS_RANGE);
+                    Set<MempoolRateSize> mempoolRateSizes = electrumServer.getMempoolRateSizes();
+                    return new FeeRatesUpdatedEvent(blockTargetFeeRates, mempoolRateSizes);
+                }
+            };
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/net/ElectrumServerRpc.java

@@ -1,6 +1,7 @@
 package com.sparrowwallet.sparrow.net;
 
 import com.github.arteam.simplejsonrpc.client.Transport;
+import com.sparrowwallet.drongo.wallet.Wallet;
 
 import java.util.List;
 import java.util.Map;
@@ -15,20 +16,22 @@ public interface ElectrumServerRpc {
 
     BlockHeaderTip subscribeBlockHeaders(Transport transport);
 
-    Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError);
+    Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError);
 
-    Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError);
+    Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError);
 
-    Map<String, String> subscribeScriptHashes(Transport transport, Map<String, String> pathScriptHashes);
+    Map<String, String> subscribeScriptHashes(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes);
 
-    Map<Integer, String> getBlockHeaders(Transport transport, Set<Integer> blockHeights);
+    Map<Integer, String> getBlockHeaders(Transport transport, Wallet wallet, Set<Integer> blockHeights);
 
-    Map<String, String> getTransactions(Transport transport, Set<String> txids);
+    Map<String, String> getTransactions(Transport transport, Wallet wallet, Set<String> txids);
 
     Map<String, VerboseTransaction> getVerboseTransactions(Transport transport, Set<String> txids, String scriptHash);
 
     Map<Integer, Double> getFeeEstimates(Transport transport, List<Integer> targetBlocks);
 
+    Map<Long, Long> getFeeRateHistogram(Transport transport);
+
     Double getMinimumRelayFee(Transport transport);
 
     String broadcastTransaction(Transport transport, String txHex);

src/main/java/com/sparrowwallet/sparrow/net/ExchangeSource.java

@@ -1,7 +1,9 @@
-package com.sparrowwallet.sparrow.io;
+package com.sparrowwallet.sparrow.net;
 
+import com.google.common.net.HostAndPort;
 import com.google.gson.Gson;
 import com.sparrowwallet.sparrow.event.ExchangeRatesUpdatedEvent;
+import com.sparrowwallet.sparrow.io.Config;
 import javafx.concurrent.ScheduledService;
 import javafx.concurrent.Service;
 import javafx.concurrent.Task;
@@ -11,6 +13,8 @@ import org.slf4j.LoggerFactory;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
@@ -48,8 +52,9 @@ public enum ExchangeSource {
 
         private CoinbaseRates getRates() {
             String url = "https://api.coinbase.com/v2/exchange-rates?currency=BTC";
+            Proxy proxy = getProxy();
 
-            try(InputStream is = new URL(url).openStream(); Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
+            try(InputStream is = (proxy == null ? new URL(url).openStream() : new URL(url).openConnection(proxy).getInputStream()); Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
                 Gson gson = new Gson();
                 return gson.fromJson(reader, CoinbaseRates.class);
             } catch (Exception e) {
@@ -78,8 +83,9 @@ public enum ExchangeSource {
 
         private CoinGeckoRates getRates() {
             String url = "https://api.coingecko.com/api/v3/exchange_rates";
+            Proxy proxy = getProxy();
 
-            try(InputStream is = new URL(url).openStream(); Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
+            try(InputStream is = (proxy == null ? new URL(url).openStream() : new URL(url).openConnection(proxy).getInputStream()); Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
                 Gson gson = new Gson();
                 return gson.fromJson(reader, CoinGeckoRates.class);
             } catch (Exception e) {
@@ -110,6 +116,17 @@ public enum ExchangeSource {
         }
     }
 
+    private static Proxy getProxy() {
+        Config config = Config.get();
+        if(config.isUseProxy()) {
+            HostAndPort proxy = HostAndPort.fromString(config.getProxyServer());
+            InetSocketAddress proxyAddress = new InetSocketAddress(proxy.getHost(), proxy.getPortOrDefault(ProxyTcpOverTlsTransport.DEFAULT_PROXY_PORT));
+            return new Proxy(Proxy.Type.SOCKS, proxyAddress);
+        }
+
+        return null;
+    }
+
     @Override
     public String toString() {
         return name;

src/main/java/com/sparrowwallet/sparrow/net/FeeRatesSource.java

@@ -0,0 +1,102 @@
+package com.sparrowwallet.sparrow.net;
+
+import com.google.common.net.HostAndPort;
+import com.google.gson.Gson;
+import com.sparrowwallet.sparrow.io.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public enum FeeRatesSource {
+    ELECTRUM_SERVER("Electrum Server") {
+        @Override
+        public Map<Integer, Double> getBlockTargetFeeRates(Map<Integer, Double> defaultblockTargetFeeRates) {
+            return Collections.emptyMap();
+        }
+    },
+    MEMPOOL_SPACE("mempool.space") {
+        @Override
+        public Map<Integer, Double> getBlockTargetFeeRates(Map<Integer, Double> defaultblockTargetFeeRates) {
+            String url = "https://mempool.space/api/v1/fees/recommended";
+            return getThreeTierFeeRates(defaultblockTargetFeeRates, url);
+        }
+    },
+    BITCOINFEES_EARN_COM("bitcoinfees.earn.com") {
+        @Override
+        public Map<Integer, Double> getBlockTargetFeeRates(Map<Integer, Double> defaultblockTargetFeeRates) {
+            String url = "https://bitcoinfees.earn.com/api/v1/fees/recommended";
+            return getThreeTierFeeRates(defaultblockTargetFeeRates, url);
+        }
+    };
+
+    private static final Logger log = LoggerFactory.getLogger(FeeRatesSource.class);
+
+    private final String name;
+
+    FeeRatesSource(String name) {
+        this.name = name;
+    }
+
+    public abstract Map<Integer, Double> getBlockTargetFeeRates(Map<Integer, Double> defaultblockTargetFeeRates);
+
+    public String getName() {
+        return name;
+    }
+
+    private static Map<Integer, Double> getThreeTierFeeRates(Map<Integer, Double> defaultblockTargetFeeRates, String url) {
+        Proxy proxy = getProxy();
+
+        Map<Integer, Double> blockTargetFeeRates = new LinkedHashMap<>();
+        try(InputStream is = (proxy == null ? new URL(url).openStream() : new URL(url).openConnection(proxy).getInputStream()); Reader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
+            Gson gson = new Gson();
+            ThreeTierRates threeTierRates = gson.fromJson(reader, ThreeTierRates.class);
+            for(Integer blockTarget : defaultblockTargetFeeRates.keySet()) {
+                if(blockTarget < 3) {
+                    blockTargetFeeRates.put(blockTarget, threeTierRates.fastestFee);
+                } else if(blockTarget < 6) {
+                    blockTargetFeeRates.put(blockTarget, threeTierRates.halfHourFee);
+                } else if(blockTarget <= 10 || defaultblockTargetFeeRates.get(blockTarget) > threeTierRates.hourFee) {
+                    blockTargetFeeRates.put(blockTarget, threeTierRates.hourFee);
+                } else {
+                    blockTargetFeeRates.put(blockTarget, defaultblockTargetFeeRates.get(blockTarget));
+                }
+            }
+        } catch (Exception e) {
+            log.warn("Error retrieving recommended fee rates from " + url, e);
+        }
+
+        return blockTargetFeeRates;
+    }
+
+    private static Proxy getProxy() {
+        Config config = Config.get();
+        if(config.isUseProxy()) {
+            HostAndPort proxy = HostAndPort.fromString(config.getProxyServer());
+            InetSocketAddress proxyAddress = new InetSocketAddress(proxy.getHost(), proxy.getPortOrDefault(ProxyTcpOverTlsTransport.DEFAULT_PROXY_PORT));
+            return new Proxy(Proxy.Type.SOCKS, proxyAddress);
+        }
+
+        return null;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    private static class ThreeTierRates {
+        Double fastestFee;
+        Double halfHourFee;
+        Double hourFee;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/net/MempoolRateSize.java

@@ -0,0 +1,51 @@
+package com.sparrowwallet.sparrow.net;
+
+import java.util.Objects;
+
+public class MempoolRateSize implements Comparable<MempoolRateSize> {
+    private final long fee;
+    private final long vSize;
+
+    public MempoolRateSize(long fee, long vSize) {
+        this.fee = fee;
+        this.vSize = vSize;
+    }
+
+    public long getFee() {
+        return fee;
+    }
+
+    public long getVSize() {
+        return vSize;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if(this == o) {
+            return true;
+        }
+        if(o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        MempoolRateSize that = (MempoolRateSize) o;
+        return fee == that.fee;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(fee);
+    }
+
+    @Override
+    public int compareTo(MempoolRateSize other) {
+        return Long.compare(fee, other.fee);
+    }
+
+    @Override
+    public String toString() {
+        return "MempoolRateSize{" +
+                "fee=" + fee +
+                ", vSize=" + vSize +
+                '}';
+    }
+}

src/main/java/com/sparrowwallet/sparrow/net/RetryLogic.java

@@ -0,0 +1,54 @@
+package com.sparrowwallet.sparrow.net;
+
+import java.util.List;
+
+/**
+ * Generic retry logic. Delegate must throw the specified exception type to trigger the retry logic.
+ */
+public class RetryLogic<T> {
+    public static interface Delegate<T> {
+        T call() throws Exception;
+    }
+
+    private final int maxAttempts;
+    private final int retryWaitSeconds;
+    @SuppressWarnings("rawtypes")
+    private final List<Class> retryExceptionTypes;
+
+    public RetryLogic(int maxAttempts, int retryWaitSeconds, @SuppressWarnings("rawtypes") Class retryExceptionType) {
+        this(maxAttempts, retryWaitSeconds, List.of(retryExceptionType));
+    }
+
+    public RetryLogic(int maxAttempts, int retryWaitSeconds, @SuppressWarnings("rawtypes") List<Class> retryExceptionTypes) {
+        this.maxAttempts = maxAttempts;
+        this.retryWaitSeconds = retryWaitSeconds;
+        this.retryExceptionTypes = retryExceptionTypes;
+    }
+
+    public T getResult(Delegate<T> caller) throws Exception {
+        T result = null;
+        int remainingAttempts = maxAttempts;
+        do {
+            try {
+                return caller.call();
+            } catch(Exception e) {
+                if(retryExceptionTypes.contains(e.getClass())) {
+                    if(--remainingAttempts == 0) {
+                        throw new ServerException("Retries exhausted", e);
+                    } else {
+                        try {
+                            Thread.sleep((1000 * retryWaitSeconds));
+                        } catch(InterruptedException ie) {
+                            //ignore
+                        }
+                    }
+                } else {
+                    throw e;
+                }
+            }
+
+        } while(remainingAttempts > 0);
+
+        throw new IllegalStateException("Should be impossible");
+    }
+}

src/main/java/com/sparrowwallet/sparrow/net/SimpleElectrumServerRpc.java

@@ -6,6 +6,7 @@ import com.github.arteam.simplejsonrpc.client.exception.JsonRpcException;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.protocol.Sha256Hash;
 import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.WalletHistoryStatusEvent;
@@ -18,6 +19,8 @@ import java.util.concurrent.atomic.AtomicLong;
 public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     private static final Logger log = LoggerFactory.getLogger(SimpleElectrumServerRpc.class);
     private static final int MAX_TARGET_BLOCKS = 25;
+    private static final int MAX_RETRIES = 10;
+    private static final int RETRY_DELAY = 1;
 
     private final AtomicLong idCounter = new AtomicLong();
 
@@ -25,8 +28,9 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     public void ping(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            client.createRequest().method("server.ping").id(idCounter.incrementAndGet()).executeNullable();
-        } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            new RetryLogic<>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().method("server.ping").id(idCounter.incrementAndGet()).executeNullable());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error pinging server", e);
         }
     }
@@ -35,9 +39,10 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     public List<String> getServerVersion(Transport transport, String clientName, String[] supportedVersions) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            //Using 1.4 as the version number as EPS tries to parse this number to a float
-            return client.createRequest().returnAsList(String.class).method("server.version").id(idCounter.incrementAndGet()).params(clientName, "1.4").execute();
-        } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            //Using 1.4 as the version number as EPS tries to parse this number to a float :(
+            return new RetryLogic<List<String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAsList(String.class).method("server.version").id(idCounter.incrementAndGet()).params(clientName, "1.4").execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting server version", e);
         }
     }
@@ -46,8 +51,9 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     public String getServerBanner(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(String.class).method("server.banner").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            return new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(String.class).method("server.banner").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting server banner", e);
         }
     }
@@ -56,23 +62,25 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     public BlockHeaderTip subscribeBlockHeaders(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(BlockHeaderTip.class).method("blockchain.headers.subscribe").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            return new RetryLogic<BlockHeaderTip>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(BlockHeaderTip.class).method("blockchain.headers.subscribe").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error subscribing to block headers", e);
         }
     }
 
     @Override
-    public Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError) {
+    public Map<String, ScriptHashTx[]> getScriptHashHistory(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError) {
         JsonRpcClient client = new JsonRpcClient(transport);
 
         Map<String, ScriptHashTx[]> result = new LinkedHashMap<>();
         for(String path : pathScriptHashes.keySet()) {
-            EventManager.get().post(new WalletHistoryStatusEvent(false, "Loading transactions for " + path));
+            EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Loading transactions for " + path));
             try {
-                ScriptHashTx[] scriptHashTxes = client.createRequest().returnAs(ScriptHashTx[].class).method("blockchain.scripthash.get_history").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).execute();
+                ScriptHashTx[] scriptHashTxes = new RetryLogic<ScriptHashTx[]>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(() ->
+                        client.createRequest().returnAs(ScriptHashTx[].class).method("blockchain.scripthash.get_history").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).execute());
                 result.put(path, scriptHashTxes);
-            } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            } catch(Exception e) {
                 if(failOnError) {
                     throw new ElectrumServerRpcException("Failed to retrieve reference for path: " + path, e);
                 }
@@ -85,15 +93,16 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     }
 
     @Override
-    public Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Map<String, String> pathScriptHashes, boolean failOnError) {
+    public Map<String, ScriptHashTx[]> getScriptHashMempool(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes, boolean failOnError) {
         JsonRpcClient client = new JsonRpcClient(transport);
 
         Map<String, ScriptHashTx[]> result = new LinkedHashMap<>();
         for(String path : pathScriptHashes.keySet()) {
             try {
-                ScriptHashTx[] scriptHashTxes = client.createRequest().returnAs(ScriptHashTx[].class).method("blockchain.scripthash.get_mempool").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).execute();
+                ScriptHashTx[] scriptHashTxes = new RetryLogic<ScriptHashTx[]>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(() ->
+                        client.createRequest().returnAs(ScriptHashTx[].class).method("blockchain.scripthash.get_mempool").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).execute());
                 result.put(path, scriptHashTxes);
-            } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            } catch(Exception e) {
                 if(failOnError) {
                     throw new ElectrumServerRpcException("Failed to retrieve reference for path: " + path, e);
                 }
@@ -106,16 +115,17 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     }
 
     @Override
-    public Map<String, String> subscribeScriptHashes(Transport transport, Map<String, String> pathScriptHashes) {
+    public Map<String, String> subscribeScriptHashes(Transport transport, Wallet wallet, Map<String, String> pathScriptHashes) {
         JsonRpcClient client = new JsonRpcClient(transport);
 
         Map<String, String> result = new LinkedHashMap<>();
         for(String path : pathScriptHashes.keySet()) {
-            EventManager.get().post(new WalletHistoryStatusEvent(false, "Finding transactions for " + path));
+            EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Finding transactions for " + path));
             try {
-                String scriptHash = client.createRequest().returnAs(String.class).method("blockchain.scripthash.subscribe").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).executeNullable();
+                String scriptHash = new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(() ->
+                        client.createRequest().returnAs(String.class).method("blockchain.scripthash.subscribe").id(path + "-" + idCounter.incrementAndGet()).params(pathScriptHashes.get(path)).executeNullable());
                 result.put(path, scriptHash);
-            } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            } catch(Exception e) {
                 //Even if we have some successes, failure to subscribe for all script hashes will result in outdated wallet view. Don't proceed.
                 throw new ElectrumServerRpcException("Failed to retrieve reference for path: " + path, e);
             }
@@ -125,19 +135,20 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     }
 
     @Override
-    public Map<Integer, String> getBlockHeaders(Transport transport, Set<Integer> blockHeights) {
+    public Map<Integer, String> getBlockHeaders(Transport transport, Wallet wallet, Set<Integer> blockHeights) {
         JsonRpcClient client = new JsonRpcClient(transport);
 
         Map<Integer, String> result = new LinkedHashMap<>();
         for(Integer blockHeight : blockHeights) {
-            EventManager.get().post(new WalletHistoryStatusEvent(false, "Retrieving block at height " + blockHeight));
+            EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Retrieving block at height " + blockHeight));
             try {
-                String blockHeader = client.createRequest().returnAs(String.class).method("blockchain.block.header").id(idCounter.incrementAndGet()).params(blockHeight).execute();
+                String blockHeader = new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(() ->
+                        client.createRequest().returnAs(String.class).method("blockchain.block.header").id(idCounter.incrementAndGet()).params(blockHeight).execute());
                 result.put(blockHeight, blockHeader);
-            } catch(IllegalStateException | IllegalArgumentException e) {
-                log.warn("Failed to retrieve block header for block height: " + blockHeight + " (" + e.getMessage() + ")");
             } catch(JsonRpcException e) {
                 log.warn("Failed to retrieve block header for block height: " + blockHeight + " (" + e.getErrorMessage() + ")");
+            } catch(Exception e) {
+                log.warn("Failed to retrieve block header for block height: " + blockHeight + " (" + e.getMessage() + ")");
             }
         }
 
@@ -145,16 +156,17 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     }
 
     @Override
-    public Map<String, String> getTransactions(Transport transport, Set<String> txids) {
+    public Map<String, String> getTransactions(Transport transport, Wallet wallet, Set<String> txids) {
         JsonRpcClient client = new JsonRpcClient(transport);
 
         Map<String, String> result = new LinkedHashMap<>();
         for(String txid : txids) {
-            EventManager.get().post(new WalletHistoryStatusEvent(false, "Retrieving transaction [" + txid.substring(0, 6) + "]"));
+            EventManager.get().post(new WalletHistoryStatusEvent(wallet, false, "Retrieving transaction [" + txid.substring(0, 6) + "]"));
             try {
-                String rawTxHex = client.createRequest().returnAs(String.class).method("blockchain.transaction.get").id(idCounter.incrementAndGet()).params(txid).execute();
+                String rawTxHex = new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(() ->
+                        client.createRequest().returnAs(String.class).method("blockchain.transaction.get").id(idCounter.incrementAndGet()).params(txid).execute());
                 result.put(txid, rawTxHex);
-            } catch(JsonRpcException | IllegalStateException | IllegalArgumentException e) {
+            } catch(Exception e) {
                 result.put(txid, Sha256Hash.ZERO_HASH.toString());
             }
         }
@@ -169,10 +181,11 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
         Map<String, VerboseTransaction> result = new LinkedHashMap<>();
         for(String txid : txids) {
             try {
-                VerboseTransaction verboseTransaction = client.createRequest().returnAs(VerboseTransaction.class).method("blockchain.transaction.get").id(idCounter.incrementAndGet()).params(txid, true).execute();
+                VerboseTransaction verboseTransaction = new RetryLogic<VerboseTransaction>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                        client.createRequest().returnAs(VerboseTransaction.class).method("blockchain.transaction.get").id(idCounter.incrementAndGet()).params(txid, true).execute());
                 result.put(txid, verboseTransaction);
             } catch(Exception e) {
-                //electrs does not currently support the verbose parameter, so try to fetch an incomplete VerboseTransaction without it
+                //electrs-esplora does not currently support the verbose parameter, so try to fetch an incomplete VerboseTransaction without it
                 //Note that without the script hash associated with the transaction, we can't get a block height as there is no way in the Electrum RPC protocol to do this
                 //We mark this VerboseTransaction as incomplete by assigning it a Sha256Hash.ZERO_HASH blockhash
                 log.debug("Error retrieving transaction: " + txid + " (" + (e.getCause() != null ? e.getCause().getMessage() : e.getMessage()) + ")");
@@ -216,13 +229,14 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
         for(Integer targetBlock : targetBlocks) {
             if(targetBlock <= MAX_TARGET_BLOCKS) {
                 try {
-                    Double targetBlocksFeeRateBtcKb = client.createRequest().returnAs(Double.class).method("blockchain.estimatefee").id(idCounter.incrementAndGet()).params(targetBlock).execute();
+                    Double targetBlocksFeeRateBtcKb = new RetryLogic<Double>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                            client.createRequest().returnAs(Double.class).method("blockchain.estimatefee").id(idCounter.incrementAndGet()).params(targetBlock).execute());
                     result.put(targetBlock, targetBlocksFeeRateBtcKb);
-                } catch(IllegalStateException | IllegalArgumentException e) {
-                    log.warn("Failed to retrieve fee rate for target blocks: " + targetBlock + " (" + e.getMessage() + ")");
-                    result.put(targetBlock, result.values().stream().mapToDouble(v -> v).min().orElse(0.0001d));
                 } catch(JsonRpcException e) {
                     throw new ElectrumServerRpcException("Failed to retrieve fee rate for target blocks: " + targetBlock, e);
+                } catch(Exception e) {
+                    log.warn("Failed to retrieve fee rate for target blocks: " + targetBlock + " (" + e.getMessage() + ")");
+                    result.put(targetBlock, result.values().stream().mapToDouble(v -> v).min().orElse(0.0001d));
                 }
             } else {
                 result.put(targetBlock, result.values().stream().mapToDouble(v -> v).min().orElse(0.0001d));
@@ -232,12 +246,31 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
         return result;
     }
 
+    @Override
+    public Map<Long, Long> getFeeRateHistogram(Transport transport) {
+        try {
+            JsonRpcClient client = new JsonRpcClient(transport);
+            Long[][] feesArray = new RetryLogic<Long[][]>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(Long[][].class).method("mempool.get_fee_histogram").id(idCounter.incrementAndGet()).execute());
+
+            Map<Long, Long> feeRateHistogram = new TreeMap<>();
+            for(Long[] feePair : feesArray) {
+                feeRateHistogram.put(feePair[0], feePair[1]);
+            }
+
+            return feeRateHistogram;
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException("Error getting fee rate histogram", e);
+        }
+    }
+
     @Override
     public Double getMinimumRelayFee(Transport transport) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(Double.class).method("blockchain.relayfee").id(idCounter.incrementAndGet()).execute();
-        } catch(JsonRpcException e) {
+            return new RetryLogic<Double>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(Double.class).method("blockchain.relayfee").id(idCounter.incrementAndGet()).execute());
+        } catch(Exception e) {
             throw new ElectrumServerRpcException("Error getting minimum relay fee", e);
         }
     }
@@ -246,11 +279,12 @@ public class SimpleElectrumServerRpc implements ElectrumServerRpc {
     public String broadcastTransaction(Transport transport, String txHex) {
         try {
             JsonRpcClient client = new JsonRpcClient(transport);
-            return client.createRequest().returnAs(String.class).method("blockchain.transaction.broadcast").id(idCounter.incrementAndGet()).params(txHex).execute();
-        } catch(IllegalStateException | IllegalArgumentException e) {
-            throw new ElectrumServerRpcException(e.getMessage(), e);
+            return new RetryLogic<String>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(() ->
+                    client.createRequest().returnAs(String.class).method("blockchain.transaction.broadcast").id(idCounter.incrementAndGet()).params(txHex).execute());
         } catch(JsonRpcException e) {
             throw new ElectrumServerRpcException(e.getErrorMessage().getMessage(), e);
+        } catch(Exception e) {
+            throw new ElectrumServerRpcException(e.getMessage(), e);
         }
     }
 }

src/main/java/com/sparrowwallet/sparrow/net/SubscriptionService.java

@@ -1,6 +1,7 @@
 package com.sparrowwallet.sparrow.net;
 
 import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcMethod;
+import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcOptional;
 import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcParam;
 import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcService;
 import com.google.common.collect.Iterables;
@@ -23,7 +24,12 @@ public class SubscriptionService {
     }
 
     @JsonRpcMethod("blockchain.scripthash.subscribe")
-    public void scriptHashStatusUpdated(@JsonRpcParam("scripthash") final String scriptHash, @JsonRpcParam("status") final String status) {
+    public void scriptHashStatusUpdated(@JsonRpcParam("scripthash") final String scriptHash, @JsonRpcOptional @JsonRpcParam("status") final String status) {
+        if(status == null) {
+            //Mempool transaction was replaced returning change/consolidation script hash status to null, ignore this update
+            return;
+        }
+
         Set<String> existingStatuses = ElectrumServer.getSubscribedScriptHashes().get(scriptHash);
         if(existingStatuses == null) {
             log.warn("Received script hash status update for unsubscribed script hash: " + scriptHash);

src/main/java/com/sparrowwallet/sparrow/net/TcpTransport.java

@@ -3,6 +3,7 @@ package com.sparrowwallet.sparrow.net;
 import com.github.arteam.simplejsonrpc.client.Transport;
 import com.github.arteam.simplejsonrpc.server.JsonRpcServer;
 import com.google.common.net.HostAndPort;
+import com.google.gson.Gson;
 import com.sparrowwallet.sparrow.io.Config;
 import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
@@ -11,6 +12,7 @@ import org.slf4j.LoggerFactory;
 import javax.net.SocketFactory;
 import java.io.*;
 import java.net.Socket;
+import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.ReentrantLock;
@@ -19,6 +21,7 @@ public class TcpTransport implements Transport, Closeable {
     private static final Logger log = LoggerFactory.getLogger(TcpTransport.class);
 
     public static final int DEFAULT_PORT = 50001;
+    private static final int[] READ_TIMEOUT_SECS = {3, 8, 16, 34};
 
     protected final HostAndPort server;
     protected final SocketFactory socketFactory;
@@ -32,13 +35,15 @@ public class TcpTransport implements Transport, Closeable {
 
     private final ReentrantLock clientRequestLock = new ReentrantLock();
     private boolean running = false;
-    private boolean reading = true;
+    private volatile boolean reading = true;
     private boolean firstRead = true;
+    private int readTimeoutIndex;
 
     private final JsonRpcServer jsonRpcServer = new JsonRpcServer();
     private final SubscriptionService subscriptionService = new SubscriptionService();
 
     private Exception lastException;
+    private final Gson gson = new Gson();
 
     public TcpTransport(HostAndPort server) {
         this.server = server;
@@ -49,8 +54,17 @@ public class TcpTransport implements Transport, Closeable {
     public @NotNull String pass(@NotNull String request) throws IOException {
         clientRequestLock.lock();
         try {
+            Rpc sentRpc = request.startsWith("{") ? gson.fromJson(request, Rpc.class) : null;
+            Rpc recvRpc;
+            String recv;
+
             writeRequest(request);
-            return readResponse();
+            do {
+                recv = readResponse();
+                recvRpc = recv.startsWith("{") ? gson.fromJson(response, Rpc.class) : null;
+            } while(!Objects.equals(recvRpc, sentRpc));
+
+            return recv;
         } finally {
             clientRequestLock.unlock();
         }
@@ -64,13 +78,19 @@ public class TcpTransport implements Transport, Closeable {
 
     private String readResponse() throws IOException {
         try {
-            if(!readLock.tryLock(60, TimeUnit.SECONDS)) {
+            if(!readLock.tryLock(READ_TIMEOUT_SECS[readTimeoutIndex], TimeUnit.SECONDS)) {
+                readTimeoutIndex = Math.min(readTimeoutIndex + 1, READ_TIMEOUT_SECS.length - 1);
+                log.debug("No response from server, setting read timeout to " + READ_TIMEOUT_SECS[readTimeoutIndex] + " secs");
                 throw new IOException("No response from server");
             }
         } catch(InterruptedException e) {
             throw new IOException("Read thread interrupted");
         }
 
+        if(readTimeoutIndex == READ_TIMEOUT_SECS.length - 1) {
+            readTimeoutIndex--;
+        }
+
         try {
             if(firstRead) {
                 readingCondition.signal();
@@ -113,7 +133,7 @@ public class TcpTransport implements Transport, Closeable {
             while(running) {
                 try {
                     String received = readInputStream();
-                    if(received.contains("method")) {
+                    if(received.contains("method") && !received.contains("error")) {
                         //Handle subscription notification
                         jsonRpcServer.handle(received, subscriptionService);
                     } else {
@@ -177,4 +197,25 @@ public class TcpTransport implements Transport, Closeable {
             socket.close();
         }
     }
+
+    private static class Rpc {
+        public String id;
+
+        @Override
+        public boolean equals(Object o) {
+            if(this == o) {
+                return true;
+            }
+            if(o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            Rpc rpc = (Rpc) o;
+            return Objects.equals(id, rpc.id);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(id);
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/payjoin/Payjoin.java

@@ -0,0 +1,321 @@
+package com.sparrowwallet.sparrow.payjoin;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.gson.Gson;
+import com.sparrowwallet.drongo.KeyPurpose;
+import com.sparrowwallet.drongo.protocol.Script;
+import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.protocol.TransactionInput;
+import com.sparrowwallet.drongo.protocol.TransactionOutput;
+import com.sparrowwallet.drongo.psbt.PSBT;
+import com.sparrowwallet.drongo.psbt.PSBTInput;
+import com.sparrowwallet.drongo.psbt.PSBTOutput;
+import com.sparrowwallet.drongo.psbt.PSBTParseException;
+import com.sparrowwallet.drongo.uri.BitcoinURI;
+import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.drongo.wallet.WalletNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.*;
+
+public class Payjoin {
+    private static final Logger log = LoggerFactory.getLogger(Payjoin.class);
+
+    private final BitcoinURI payjoinURI;
+    private final Wallet wallet;
+    private final PSBT psbt;
+
+    public Payjoin(BitcoinURI payjoinURI, Wallet wallet, PSBT psbt) {
+        this.payjoinURI = payjoinURI;
+        this.wallet = wallet;
+        this.psbt = psbt;
+
+        for(PSBTInput psbtInput : psbt.getPsbtInputs()) {
+            if(psbtInput.getUtxo() == null) {
+                throw new IllegalArgumentException("Original PSBT for payjoin transaction must have non_witness_utxo or witness_utxo fields for all inputs");
+            }
+        }
+
+        if(!psbt.isFinalized()) {
+            throw new IllegalArgumentException("Original PSBT for payjoin transaction must be finalized");
+        }
+    }
+
+    public PSBT requestPayjoinPSBT(boolean allowOutputSubstitution) throws PayjoinReceiverException {
+        if(!payjoinURI.isPayjoinOutputSubstitutionAllowed()) {
+            allowOutputSubstitution = false;
+        }
+
+        URI uri = payjoinURI.getPayjoinUrl();
+        if(uri == null) {
+            log.error("No payjoin URL provided");
+            throw new PayjoinReceiverException("No payjoin URL provided");
+        }
+
+        try {
+            String base64Psbt = psbt.getPublicCopy().toBase64String();
+
+            String appendQuery = "v=1";
+            int changeOutputIndex = getChangeOutputIndex();
+            long maxAdditionalFeeContribution = 0;
+            if(changeOutputIndex > -1) {
+                appendQuery += "&additionalfeeoutputindex=" + changeOutputIndex;
+                maxAdditionalFeeContribution = getAdditionalFeeContribution();
+                appendQuery += "&maxadditionalfeecontribution=" + maxAdditionalFeeContribution;
+            }
+
+            URI finalUri = new URI(uri.getScheme(), uri.getAuthority(), uri.getPath(), uri.getQuery() == null ? appendQuery : uri.getQuery() + "&" + appendQuery, uri.getFragment());
+            log.info("Sending PSBT to " + finalUri.toURL());
+
+            HttpClient client = HttpClient.newHttpClient();
+            HttpRequest request = HttpRequest.newBuilder()
+                    .uri(finalUri)
+                    .header("Content-Type", "text/plain")
+                    .POST(HttpRequest.BodyPublishers.ofString(base64Psbt))
+                    .build();
+
+            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+            if(response.statusCode() != 200) {
+                Gson gson = new Gson();
+                PayjoinReceiverError payjoinReceiverError = gson.fromJson(response.body(), PayjoinReceiverError.class);
+                log.warn("Payjoin receiver returned an error of " + payjoinReceiverError.getErrorCode() + " (" + payjoinReceiverError.getMessage() + ")");
+                throw new PayjoinReceiverException(payjoinReceiverError.getSafeMessage());
+            }
+
+            PSBT proposalPsbt = PSBT.fromString(response.body());
+            checkProposal(psbt, proposalPsbt, changeOutputIndex, maxAdditionalFeeContribution, allowOutputSubstitution);
+
+            return proposalPsbt;
+        } catch(URISyntaxException e) {
+            log.error("Invalid payjoin receiver URI", e);
+            throw new PayjoinReceiverException("Invalid payjoin receiver URI", e);
+        } catch(IOException | InterruptedException e) {
+            log.error("Payjoin receiver error", e);
+            throw new PayjoinReceiverException("Payjoin receiver error", e);
+        } catch(PSBTParseException e) {
+            log.error("Error parsing received PSBT", e);
+            throw new PayjoinReceiverException("Payjoin receiver returned invalid PSBT", e);
+        }
+    }
+
+    private void checkProposal(PSBT original, PSBT proposal, int changeOutputIndex, long maxAdditionalFeeContribution, boolean allowOutputSubstitution) throws PayjoinReceiverException {
+        Queue<Map.Entry<TransactionInput, PSBTInput>> originalInputs = new ArrayDeque<>();
+        for(int i = 0; i < original.getPsbtInputs().size(); i++) {
+            originalInputs.add(Map.entry(original.getTransaction().getInputs().get(i), original.getPsbtInputs().get(i)));
+        }
+
+        Queue<Map.Entry<TransactionOutput, PSBTOutput>> originalOutputs = new ArrayDeque<>();
+        for(int i = 0; i < original.getPsbtOutputs().size(); i++) {
+            originalOutputs.add(Map.entry(original.getTransaction().getOutputs().get(i), original.getPsbtOutputs().get(i)));
+        }
+
+        // Checking that the PSBT of the receiver is clean
+        if(!proposal.getExtendedPublicKeys().isEmpty()) {
+            throw new PayjoinReceiverException("Global xpubs should not be included in the receiver's PSBT");
+        }
+
+        Transaction originalTx = original.getTransaction();
+        Transaction proposalTx = proposal.getTransaction();
+        // Verify that the transaction version, and nLockTime are unchanged.
+        if(proposalTx.getVersion() != originalTx.getVersion()) {
+            throw new PayjoinReceiverException("The proposal PSBT changed the transaction version");
+        }
+        if(proposalTx.getLocktime() != originalTx.getLocktime()) {
+            throw new PayjoinReceiverException("The proposal PSBT changed the nLocktime");
+        }
+
+        Set<Long> sequences = new HashSet<>();
+        // For each inputs in the proposal:
+        for(PSBTInput proposedPSBTInput : proposal.getPsbtInputs()) {
+            if(!proposedPSBTInput.getDerivedPublicKeys().isEmpty()) {
+                throw new PayjoinReceiverException("The receiver added keypaths to an input");
+            }
+            if(!proposedPSBTInput.getPartialSignatures().isEmpty()) {
+                throw new PayjoinReceiverException("The receiver added partial signatures to an input");
+            }
+
+            TransactionInput proposedTxIn = proposedPSBTInput.getInput();
+            boolean isOriginalInput = originalInputs.size() > 0 && originalInputs.peek().getKey().getOutpoint().equals(proposedTxIn.getOutpoint());
+            if(isOriginalInput) {
+                Map.Entry<TransactionInput, PSBTInput> originalInput = originalInputs.remove();
+                TransactionInput originalTxIn = originalInput.getKey();
+
+                // Verify that sequence is unchanged.
+                if(originalTxIn.getSequenceNumber() != proposedTxIn.getSequenceNumber()) {
+                    throw new PayjoinReceiverException("The proposed transaction input modified the sequence of one of the original inputs");
+                }
+                // Verify the PSBT input is not finalized
+                if(proposedPSBTInput.isFinalized()) {
+                    throw new PayjoinReceiverException("The receiver finalized one of the original inputs");
+                }
+                // Verify that non_witness_utxo and witness_utxo are not specified.
+                if(proposedPSBTInput.getNonWitnessUtxo() != null || proposedPSBTInput.getWitnessUtxo() != null) {
+                    throw new PayjoinReceiverException("The receiver added non_witness_utxo or witness_utxo to one of the original inputs");
+                }
+                sequences.add(proposedTxIn.getSequenceNumber());
+
+                PSBTInput originalPSBTInput = originalInput.getValue();
+                // Fill up the info from the original PSBT input so we can sign and get fees.
+                proposedPSBTInput.setNonWitnessUtxo(originalPSBTInput.getNonWitnessUtxo());
+                proposedPSBTInput.setWitnessUtxo(originalPSBTInput.getWitnessUtxo());
+                // We fill up information we had on the signed PSBT, so we can sign it.
+                proposedPSBTInput.getDerivedPublicKeys().putAll(originalPSBTInput.getDerivedPublicKeys());
+                proposedPSBTInput.getProprietary().putAll(originalPSBTInput.getProprietary());
+                proposedPSBTInput.setRedeemScript(originalPSBTInput.getFinalScriptSig().getFirstNestedScript());
+                proposedPSBTInput.setWitnessScript(originalPSBTInput.getFinalScriptWitness().getWitnessScript());
+                proposedPSBTInput.setSigHash(originalPSBTInput.getSigHash());
+            } else {
+                // Verify the PSBT input is finalized
+                if(!proposedPSBTInput.isFinalized()) {
+                    throw new PayjoinReceiverException("The receiver did not finalize one of their inputs");
+                }
+                // Verify that non_witness_utxo or witness_utxo are filled in.
+                if(proposedPSBTInput.getNonWitnessUtxo() == null && proposedPSBTInput.getWitnessUtxo() == null) {
+                    throw new PayjoinReceiverException("The receiver did not specify non_witness_utxo or witness_utxo for one of their inputs");
+                }
+                sequences.add(proposedTxIn.getSequenceNumber());
+                // Verify that the payjoin proposal did not introduced mixed inputs' type.
+                if(wallet.getScriptType() != proposedPSBTInput.getScriptType()) {
+                    throw new PayjoinReceiverException("Proposal script type of " + proposedPSBTInput.getScriptType() + " did not match wallet script type of " + wallet.getScriptType());
+                }
+            }
+        }
+
+        // Verify that all of sender's inputs from the original PSBT are in the proposal.
+        if(!originalInputs.isEmpty()) {
+            throw new PayjoinReceiverException("Some of the original inputs are not included in the proposal");
+        }
+
+        // Verify that the payjoin proposal did not introduced mixed inputs' sequence.
+        if(sequences.size() != 1) {
+            throw new PayjoinReceiverException("Mixed sequences detected in the proposal");
+        }
+
+        Long newFee = proposal.getFee();
+        long additionalFee = newFee - original.getFee();
+        if(additionalFee < 0) {
+            throw new PayjoinReceiverException("The receiver decreased absolute fee");
+        }
+
+        TransactionOutput changeOutput = (changeOutputIndex > -1 ? originalTx.getOutputs().get(changeOutputIndex) : null);
+
+        // For each outputs in the proposal:
+        for(int i = 0; i < proposal.getPsbtOutputs().size(); i++) {
+            PSBTOutput proposedPSBTOutput = proposal.getPsbtOutputs().get(i);
+            // Verify that no keypaths is in the PSBT output
+            if(!proposedPSBTOutput.getDerivedPublicKeys().isEmpty()) {
+                throw new PayjoinReceiverException("The receiver added keypaths to an output");
+            }
+
+            TransactionOutput proposedTxOut = proposalTx.getOutputs().get(i);
+            boolean isOriginalOutput = originalOutputs.size() > 0 && originalOutputs.peek().getKey().getScript().equals(proposedTxOut.getScript());
+            if(isOriginalOutput) {
+                Map.Entry<TransactionOutput, PSBTOutput> originalOutput = originalOutputs.remove();
+                if(originalOutput.getKey() == changeOutput) {
+                    var actualContribution = changeOutput.getValue() - proposedTxOut.getValue();
+                    // The amount that was subtracted from the output's value is less than or equal to maxadditionalfeecontribution
+                    if(actualContribution > maxAdditionalFeeContribution) {
+                        throw new PayjoinReceiverException("The actual contribution is more than maxadditionalfeecontribution");
+                    }
+                    // Make sure the actual contribution is only paying fee
+                    if(actualContribution > additionalFee) {
+                        throw new PayjoinReceiverException("The actual contribution is not only paying fee");
+                    }
+                    // Make sure the actual contribution is only paying for fee incurred by additional inputs
+                    int additionalInputsCount = proposalTx.getInputs().size() - originalTx.getInputs().size();
+                    if(actualContribution > getSingleInputFee() * additionalInputsCount) {
+                        throw new PayjoinReceiverException("The actual contribution is not only paying for additional inputs");
+                    }
+                } else if(allowOutputSubstitution && originalOutput.getKey().getScript().equals(payjoinURI.getAddress().getOutputScript())) {
+                    // That's the payment output, the receiver may have changed it.
+                } else {
+                    if(originalOutput.getKey().getValue() > proposedTxOut.getValue()) {
+                        throw new PayjoinReceiverException("The receiver decreased the value of one of the outputs");
+                    }
+                }
+
+                PSBTOutput originalPSBTOutput = originalOutput.getValue();
+                // We fill up information we had on the signed PSBT, so we can sign it.
+                proposedPSBTOutput.getDerivedPublicKeys().putAll(originalPSBTOutput.getDerivedPublicKeys());
+                proposedPSBTOutput.getProprietary().putAll(originalPSBTOutput.getProprietary());
+                proposedPSBTOutput.setRedeemScript(originalPSBTOutput.getRedeemScript());
+                proposedPSBTOutput.setWitnessScript(originalPSBTOutput.getWitnessScript());
+            }
+        }
+
+        // Verify that all of sender's outputs from the original PSBT are in the proposal.
+        if(!originalOutputs.isEmpty()) {
+            // The payment output may have been substituted
+            if(!allowOutputSubstitution || originalOutputs.size() != 1 || !originalOutputs.remove().getKey().getScript().equals(payjoinURI.getAddress().getOutputScript())) {
+                throw new PayjoinReceiverException("Some of our outputs are not included in the proposal");
+            }
+        }
+
+        //Add global pubkey map for signing
+        proposal.getExtendedPublicKeys().putAll(psbt.getExtendedPublicKeys());
+        proposal.getGlobalProprietary().putAll(psbt.getGlobalProprietary());
+    }
+
+    private int getChangeOutputIndex() {
+        Map<Script, WalletNode> changeScriptNodes = wallet.getWalletOutputScripts(KeyPurpose.CHANGE);
+        for(int i = 0; i < psbt.getTransaction().getOutputs().size(); i++) {
+            if(changeScriptNodes.containsKey(psbt.getTransaction().getOutputs().get(i).getScript())) {
+                return i;
+            }
+        }
+
+        return -1;
+    }
+
+    private long getAdditionalFeeContribution() {
+        return getSingleInputFee();
+    }
+
+    private long getSingleInputFee() {
+        Transaction transaction = psbt.extractTransaction();
+        double feeRate = psbt.getFee().doubleValue() / transaction.getVirtualSize();
+        int vSize = 68;
+
+        if(transaction.getInputs().size() > 0) {
+            TransactionInput input = transaction.getInputs().get(0);
+            vSize = input.getLength() * Transaction.WITNESS_SCALE_FACTOR;
+            vSize += input.getWitness() != null ? input.getWitness().getLength() : 0;
+            vSize = (int)Math.ceil((double)vSize / Transaction.WITNESS_SCALE_FACTOR);
+        }
+
+        return (long) (vSize * feeRate);
+    }
+
+    private static class PayjoinReceiverError {
+        Map<String, String> knownErrors = ImmutableMap.of(
+                "unavailable", "The payjoin endpoint is not available for now.",
+                "not-enough-money", "The receiver added some inputs but could not bump the fee of the payjoin proposal.",
+                "version-unsupported", "This version of payjoin is not supported.",
+                "original-psbt-rejected", "The receiver rejected the original PSBT."
+        );
+
+        public String errorCode;
+        public String message;
+
+        public String getErrorCode() {
+            return errorCode;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public String getSafeMessage() {
+            String message = knownErrors.get(errorCode);
+            return (message == null ? "Unknown Error" : message);
+        }
+    }
+}

src/main/java/com/sparrowwallet/sparrow/payjoin/PayjoinReceiverException.java

@@ -0,0 +1,19 @@
+package com.sparrowwallet.sparrow.payjoin;
+
+public class PayjoinReceiverException extends Exception {
+    public PayjoinReceiverException() {
+        super();
+    }
+
+    public PayjoinReceiverException(String msg) {
+        super(msg);
+    }
+
+    public PayjoinReceiverException(Throwable cause) {
+        super(cause);
+    }
+
+    public PayjoinReceiverException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/com/sparrowwallet/sparrow/preferences/GeneralPreferencesController.java

@@ -3,11 +3,10 @@ package com.sparrowwallet.sparrow.preferences;
 import com.sparrowwallet.drongo.BitcoinUnit;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.UnlabeledToggleSwitch;
-import com.sparrowwallet.sparrow.event.BitcoinUnitChangedEvent;
-import com.sparrowwallet.sparrow.event.FiatCurrencySelectedEvent;
-import com.sparrowwallet.sparrow.event.VersionCheckStatusEvent;
+import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.io.Config;
-import com.sparrowwallet.sparrow.io.ExchangeSource;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
+import com.sparrowwallet.sparrow.net.FeeRatesSource;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
 import javafx.fxml.FXML;
@@ -24,6 +23,9 @@ public class GeneralPreferencesController extends PreferencesDetailController {
     @FXML
     private ComboBox<BitcoinUnit> bitcoinUnit;
 
+    @FXML
+    private ComboBox<FeeRatesSource> feeRatesSource;
+
     @FXML
     private ComboBox<Currency> fiatCurrency;
 
@@ -63,6 +65,18 @@ public class GeneralPreferencesController extends PreferencesDetailController {
             EventManager.get().post(new BitcoinUnitChangedEvent(newValue));
         });
 
+        if(config.getFeeRatesSource() != null) {
+            feeRatesSource.setValue(config.getFeeRatesSource());
+        } else {
+            feeRatesSource.getSelectionModel().select(1);
+            config.setFeeRatesSource(feeRatesSource.getValue());
+        }
+
+        feeRatesSource.valueProperty().addListener((observable, oldValue, newValue) -> {
+            config.setFeeRatesSource(newValue);
+            EventManager.get().post(new FeeRatesSourceChangedEvent(newValue));
+        });
+
         if(config.getExchangeSource() != null) {
             exchangeSource.setValue(config.getExchangeSource());
         } else {

src/main/java/com/sparrowwallet/sparrow/preferences/PreferencesDialog.java

@@ -49,7 +49,7 @@ public class PreferencesDialog extends Dialog<Boolean> {
             }
 
             dialogPane.setPrefWidth(650);
-            dialogPane.setPrefHeight(500);
+            dialogPane.setPrefHeight(550);
 
             existingConnection = ElectrumServer.isConnected();
             setOnCloseRequest(event -> {

src/main/java/com/sparrowwallet/sparrow/preferences/ServerPreferencesController.java

@@ -109,7 +109,7 @@ public class ServerPreferencesController extends PreferencesDetailController {
             FileChooser fileChooser = new FileChooser();
             fileChooser.setTitle("Select Electrum Server certificate");
             fileChooser.getExtensionFilters().addAll(
-                    new FileChooser.ExtensionFilter("All Files", "*.*"),
+                    new FileChooser.ExtensionFilter("All Files", org.controlsfx.tools.Platform.getCurrent().equals(org.controlsfx.tools.Platform.UNIX) ? "*" : "*.*"),
                     new FileChooser.ExtensionFilter("CRT", "*.crt")
             );
 
@@ -296,6 +296,10 @@ public class ServerPreferencesController extends PreferencesDetailController {
     @NotNull
     private ChangeListener<String> getProxyListener(Config config) {
         return (observable, oldValue, newValue) -> {
+            if(oldValue.trim().equals(newValue.trim())) {
+                return;
+            }
+
             String hostAsString = getHost(proxyHost.getText());
             Integer portAsInteger = getPort(proxyPort.getText());
             if(hostAsString != null && portAsInteger != null && isValidPort(portAsInteger)) {

src/main/java/com/sparrowwallet/sparrow/transaction/HeadersController.java

@@ -3,10 +3,14 @@ package com.sparrowwallet.sparrow.transaction;
 import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.Utils;
+import com.sparrowwallet.drongo.address.Address;
 import com.sparrowwallet.drongo.protocol.*;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.psbt.PSBTInput;
+import com.sparrowwallet.drongo.uri.BitcoinURI;
 import com.sparrowwallet.drongo.wallet.*;
+import com.sparrowwallet.hummingbird.UR;
+import com.sparrowwallet.hummingbird.registry.RegistryType;
 import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.*;
@@ -15,6 +19,8 @@ import com.sparrowwallet.sparrow.glyphfont.FontAwesome5Brands;
 import com.sparrowwallet.sparrow.io.Device;
 import com.sparrowwallet.sparrow.net.ElectrumServer;
 import com.sparrowwallet.sparrow.io.Storage;
+import com.sparrowwallet.sparrow.payjoin.Payjoin;
+import com.sparrowwallet.sparrow.payjoin.PayjoinReceiverException;
 import com.sparrowwallet.sparrow.wallet.HashIndexEntry;
 import com.sparrowwallet.sparrow.wallet.TransactionEntry;
 import javafx.application.Platform;
@@ -39,10 +45,8 @@ import tornadofx.control.Fieldset;
 import com.google.common.eventbus.Subscribe;
 import tornadofx.control.Form;
 
-import java.io.File;
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.net.URL;
+import java.io.*;
+import java.net.*;
 import java.nio.charset.StandardCharsets;
 import java.text.SimpleDateFormat;
 import java.time.*;
@@ -195,6 +199,9 @@ public class HeadersController extends TransactionFormController implements Init
     @FXML
     private Button saveFinalButton;
 
+    @FXML
+    private Button payjoinButton;
+
     @Override
     public void initialize(URL location, ResourceBundle resources) {
         EventManager.get().register(this);
@@ -355,6 +362,12 @@ public class HeadersController extends TransactionFormController implements Init
         saveFinalButton.visibleProperty().bind(broadcastButton.visibleProperty().not());
         broadcastButton.visibleProperty().bind(AppController.onlineProperty());
 
+        BitcoinURI payjoinURI = getPayjoinURI();
+        boolean isPayjoinOriginalTx = payjoinURI != null && headersForm.getPsbt() != null && headersForm.getPsbt().getPsbtInputs().stream().noneMatch(PSBTInput::isFinalized);
+        payjoinButton.managedProperty().bind(payjoinButton.visibleProperty());
+        payjoinButton.visibleProperty().set(isPayjoinOriginalTx);
+        broadcastButton.setDefaultButton(!isPayjoinOriginalTx);
+
         blockchainForm.setVisible(false);
         signingWalletForm.setVisible(false);
         sigHashForm.setVisible(false);
@@ -364,7 +377,6 @@ public class HeadersController extends TransactionFormController implements Init
         broadcastButtonBox.setVisible(false);
 
         if(headersForm.getBlockTransaction() != null) {
-            blockchainForm.setVisible(true);
             updateBlockchainForm(headersForm.getBlockTransaction(), AppController.getCurrentBlockHeight());
         } else if(headersForm.getPsbt() != null) {
             PSBT psbt = headersForm.getPsbt();
@@ -469,6 +481,7 @@ public class HeadersController extends TransactionFormController implements Init
     }
 
     private void updateBlockchainForm(BlockTransaction blockTransaction, Integer currentHeight) {
+        signaturesForm.setVisible(false);
         blockchainForm.setVisible(true);
 
         if(Sha256Hash.ZERO_HASH.equals(blockTransaction.getBlockHash()) && blockTransaction.getHeight() == 0 && headersForm.getSigningWallet() == null) {
@@ -540,6 +553,24 @@ public class HeadersController extends TransactionFormController implements Init
         }
     }
 
+    private BitcoinURI getPayjoinURI() {
+        if(headersForm.getPsbt() != null) {
+            for(TransactionOutput txOutput : headersForm.getPsbt().getTransaction().getOutputs()) {
+                try {
+                    Address address = txOutput.getScript().getToAddresses()[0];
+                    BitcoinURI bitcoinURI = AppController.getPayjoinURI(address);
+                    if(bitcoinURI != null) {
+                        return bitcoinURI;
+                    }
+                } catch(Exception e) {
+                    //ignore
+                }
+            }
+        }
+
+        return null;
+    }
+
     private static class BlockHeightContextMenu extends ContextMenu {
         public BlockHeightContextMenu(Sha256Hash blockHash) {
             MenuItem copyBlockHash = new MenuItem("Copy Block Hash");
@@ -555,7 +586,7 @@ public class HeadersController extends TransactionFormController implements Init
 
     private void updateTxId() {
         id.setText(headersForm.getTransaction().calculateTxId(false).toString());
-        if(headersForm.getPsbt() != null && !(headersForm.getTransaction().hasScriptSigs() || headersForm.getTransaction().hasWitnesses())) {
+        if(!headersForm.isTransactionFinalized()) {
             if(!id.getStyleClass().contains(UNFINALIZED_TXID_CLASS)) {
                 id.getStyleClass().add(UNFINALIZED_TXID_CLASS);
             }
@@ -589,8 +620,15 @@ public class HeadersController extends TransactionFormController implements Init
         ToggleButton toggleButton = (ToggleButton)event.getSource();
         toggleButton.setSelected(false);
 
-        QRDisplayDialog qrDisplayDialog = new QRDisplayDialog(headersForm.getPsbt().serialize());
-        qrDisplayDialog.show();
+        //TODO: Remove once Cobo Vault has upgraded to UR2.0
+        boolean addLegacyEncodingOption = headersForm.getSigningWallet().getKeystores().stream().anyMatch(keystore -> keystore.getWalletModel().equals(WalletModel.COBO_VAULT));
+
+        try {
+            QRDisplayDialog qrDisplayDialog = new QRDisplayDialog(RegistryType.CRYPTO_PSBT.toString(), headersForm.getPsbt().serialize(), addLegacyEncodingOption);
+            qrDisplayDialog.show();
+        } catch(UR.URException e) {
+            log.error("Error creating PSBT UR", e);
+        }
     }
 
     public void scanPSBT(ActionEvent event) {
@@ -783,6 +821,21 @@ public class HeadersController extends TransactionFormController implements Init
         }
     }
 
+    public void getPayjoinTransaction(ActionEvent event) {
+        BitcoinURI payjoinURI = getPayjoinURI();
+        if(payjoinURI == null) {
+            throw new IllegalStateException("No valid Payjoin URI");
+        }
+
+        try {
+            Payjoin payjoin = new Payjoin(payjoinURI, headersForm.getSigningWallet(), headersForm.getPsbt());
+            PSBT proposalPsbt = payjoin.requestPayjoinPSBT(true);
+            EventManager.get().post(new ViewPSBTEvent(headersForm.getName() + " Payjoin", proposalPsbt));
+        } catch(PayjoinReceiverException e) {
+            AppController.showErrorDialog("Invalid Payjoin Transaction", e.getMessage());
+        }
+    }
+
     @Override
     public void update() {
         BlockTransaction blockTransaction = headersForm.getBlockTransaction();
@@ -832,7 +885,7 @@ public class HeadersController extends TransactionFormController implements Init
     @Subscribe
     public void openWallets(OpenWalletsEvent event) {
         if(headersForm.getPsbt() != null && headersForm.getBlockTransaction() == null) {
-            List<Wallet> availableWallets = event.getWallets().stream().filter(wallet -> wallet.canSign(headersForm.getPsbt())).collect(Collectors.toList());
+            List<Wallet> availableWallets = event.getWallets().stream().filter(wallet -> wallet.canSign(headersForm.getPsbt())).sorted(new WalletSignComparator()).collect(Collectors.toList());
             Map<Wallet, Storage> availableWalletsMap = new LinkedHashMap<>(event.getWalletsMap());
             availableWalletsMap.keySet().retainAll(availableWallets);
             headersForm.getAvailableWallets().keySet().retainAll(availableWallets);
@@ -931,6 +984,10 @@ public class HeadersController extends TransactionFormController implements Init
     @Subscribe
     public void psbtFinalized(PSBTFinalizedEvent event) {
         if(event.getPsbt().equals(headersForm.getPsbt())) {
+            if(headersForm.getSigningWallet() != null) {
+                updateSignedKeystores(headersForm.getSigningWallet());
+            }
+
             signButtonBox.setVisible(false);
             broadcastButtonBox.setVisible(true);
         }
@@ -956,7 +1013,7 @@ public class HeadersController extends TransactionFormController implements Init
 
     @Subscribe
     public void walletNodeHistoryChanged(WalletNodeHistoryChangedEvent event) {
-        if(headersForm.getSigningWallet() != null && event.getWalletNode(headersForm.getSigningWallet()) != null) {
+        if(headersForm.getSigningWallet() != null && event.getWalletNode(headersForm.getSigningWallet()) != null && headersForm.isTransactionFinalized()) {
             Sha256Hash txid = headersForm.getTransaction().getTxId();
             ElectrumServer.TransactionReferenceService transactionReferenceService = new ElectrumServer.TransactionReferenceService(Set.of(txid), event.getScriptHash());
             transactionReferenceService.setOnSucceeded(successEvent -> {
@@ -964,7 +1021,6 @@ public class HeadersController extends TransactionFormController implements Init
                 BlockTransaction blockTransaction = transactionMap.get(txid);
                 if(blockTransaction != null) {
                     headersForm.setBlockTransaction(blockTransaction);
-                    signaturesForm.setVisible(false);
                     updateBlockchainForm(blockTransaction, AppController.getCurrentBlockHeight());
                 }
             });
@@ -1011,4 +1067,18 @@ public class HeadersController extends TransactionFormController implements Init
             futureBlockWarning.setVisible(AppController.getCurrentBlockHeight() != null && locktimeBlock.getValue() > event.getHeight());
         }
     }
+
+    private static class WalletSignComparator implements Comparator<Wallet> {
+        private static final List<KeystoreSource> sourceOrder = List.of(KeystoreSource.SW_WATCH, KeystoreSource.HW_AIRGAPPED, KeystoreSource.HW_USB, KeystoreSource.SW_SEED);
+
+        @Override
+        public int compare(Wallet wallet1, Wallet wallet2) {
+            return getHighestSourceIndex(wallet2) - getHighestSourceIndex(wallet1);
+
+        }
+
+        private int getHighestSourceIndex(Wallet wallet) {
+            return wallet.getKeystores().stream().map(keystore -> sourceOrder.indexOf(keystore.getSource())).mapToInt(v -> v).max().orElse(0);
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/transaction/InputController.java

@@ -8,6 +8,7 @@ import com.sparrowwallet.drongo.protocol.*;
 import com.sparrowwallet.drongo.psbt.PSBTInput;
 import com.sparrowwallet.drongo.wallet.BlockTransaction;
 import com.sparrowwallet.drongo.wallet.Keystore;
+import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.*;
 import com.sparrowwallet.sparrow.event.*;
@@ -120,6 +121,11 @@ public class InputController extends TransactionFormController implements Initia
         TransactionInput txInput = inputForm.getTransactionInput();
         PSBTInput psbtInput = inputForm.getPsbtInput();
 
+        inputForm.signingWalletProperty().addListener((observable, oldValue, signingWallet) -> {
+            updateInputLegendFromWallet(txInput, signingWallet);
+        });
+        updateInputLegendFromWallet(txInput, inputForm.getSigningWallet());
+
         initializeInputFields(txInput, psbtInput);
         initializeScriptFields(txInput, psbtInput);
         initializeStatusFields(txInput, psbtInput);
@@ -132,9 +138,27 @@ public class InputController extends TransactionFormController implements Initia
         }
     }
 
-    private void initializeInputFields(TransactionInput txInput, PSBTInput psbtInput) {
-        inputFieldset.setText("Input #" + txInput.getIndex());
+    private String getLegendText(TransactionInput txInput) {
+        return "Input #" + txInput.getIndex();
+    }
 
+    private void updateInputLegendFromWallet(TransactionInput txInput, Wallet signingWallet) {
+        String baseText = getLegendText(txInput);
+        if(signingWallet != null) {
+            if(inputForm.isWalletTxo()) {
+                inputFieldset.setText(baseText + " - " + signingWallet.getName());
+                inputFieldset.setIcon(TransactionDiagram.getTxoGlyph());
+            } else {
+                inputFieldset.setText(baseText + " - Payjoin");
+                inputFieldset.setIcon(TransactionDiagram.getPayjoinGlyph());
+            }
+        } else {
+            inputFieldset.setText(baseText);
+            inputFieldset.setIcon(null);
+        }
+    }
+
+    private void initializeInputFields(TransactionInput txInput, PSBTInput psbtInput) {
         outpoint.managedProperty().bind(outpoint.visibleProperty());
         linkedOutpoint.managedProperty().bind(linkedOutpoint.visibleProperty());
 

src/main/java/com/sparrowwallet/sparrow/transaction/InputForm.java

@@ -46,6 +46,11 @@ public class InputForm extends IndexedTransactionForm {
         return null;
     }
 
+    public boolean isWalletTxo() {
+        TransactionInput txInput = getTransactionInput();
+        return getSigningWallet() != null && getSigningWallet().getWalletTxos().keySet().stream().anyMatch(ref -> ref.getHash().equals(txInput.getOutpoint().getHash()) && ref.getIndex() == txInput.getOutpoint().getIndex());
+    }
+
     @Override
     public Node getContents() throws IOException {
         FXMLLoader loader = new FXMLLoader(getClass().getResource("input.fxml"));

src/main/java/com/sparrowwallet/sparrow/transaction/OutputController.java

@@ -1,7 +1,6 @@
 package com.sparrowwallet.sparrow.transaction;
 
 import com.google.common.eventbus.Subscribe;
-import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.address.Address;
 import com.sparrowwallet.drongo.protocol.NonStandardScriptException;
 import com.sparrowwallet.drongo.protocol.TransactionInput;
@@ -106,10 +105,10 @@ public class OutputController extends TransactionFormController implements Initi
     private void updateOutputLegendFromWallet(TransactionOutput txOutput, Wallet signingWallet) {
         String baseText = getLegendText(txOutput);
         if(signingWallet != null) {
-            if(signingWallet.getWalletOutputScripts(KeyPurpose.RECEIVE).containsKey(txOutput.getScript())) {
+            if(outputForm.isWalletConsolidation()) {
                 outputFieldset.setText(baseText + " - Consolidation");
                 outputFieldset.setIcon(TransactionDiagram.getConsolidationGlyph());
-            } else if(signingWallet.getWalletOutputScripts(KeyPurpose.CHANGE).containsKey(txOutput.getScript())) {
+            } else if(outputForm.isWalletChange()) {
                 outputFieldset.setText(baseText + " - Change");
                 outputFieldset.setIcon(TransactionDiagram.getChangeGlyph());
             } else {

src/main/java/com/sparrowwallet/sparrow/transaction/OutputForm.java

@@ -1,5 +1,6 @@
 package com.sparrowwallet.sparrow.transaction;
 
+import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.protocol.TransactionOutput;
 import com.sparrowwallet.drongo.psbt.PSBTOutput;
 import javafx.fxml.FXMLLoader;
@@ -30,6 +31,18 @@ public class OutputForm extends IndexedTransactionForm {
         return psbtOutput;
     }
 
+    public boolean isWalletConsolidation() {
+        return (getSigningWallet() != null && getSigningWallet().getWalletOutputScripts(KeyPurpose.RECEIVE).containsKey(getTransactionOutput().getScript()));
+    }
+
+    public boolean isWalletChange() {
+        return (getSigningWallet() != null && getSigningWallet().getWalletOutputScripts(KeyPurpose.CHANGE).containsKey(getTransactionOutput().getScript()));
+    }
+
+    public boolean isWalletPayment() {
+        return getSigningWallet() != null;
+    }
+
     @Override
     public Node getContents() throws IOException {
         FXMLLoader loader = new FXMLLoader(getClass().getResource("output.fxml"));

src/main/java/com/sparrowwallet/sparrow/transaction/TransactionController.java

@@ -9,6 +9,7 @@ import com.sparrowwallet.drongo.wallet.BlockTransaction;
 import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.TransactionTabData;
+import com.sparrowwallet.sparrow.control.TransactionDiagram;
 import com.sparrowwallet.sparrow.control.TransactionHexArea;
 import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.net.ElectrumServer;
@@ -17,11 +18,10 @@ import javafx.fxml.FXML;
 import javafx.fxml.Initializable;
 import javafx.scene.Node;
 import javafx.scene.Parent;
+import javafx.scene.control.TreeCell;
 import javafx.scene.control.TreeItem;
 import javafx.scene.control.TreeView;
-import javafx.scene.control.cell.TextFieldTreeCell;
 import javafx.scene.layout.Pane;
-import javafx.util.StringConverter;
 import org.controlsfx.control.MasterDetailPane;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -125,17 +125,46 @@ public class TransactionController implements Initializable {
         rootItem.getChildren().add(outputsItem);
         txtree.setRoot(rootItem);
 
-        txtree.setCellFactory(p -> new TextFieldTreeCell<>(new StringConverter<TransactionForm>() {
+        txtree.setCellFactory(tc -> new TreeCell<>() {
             @Override
-            public String toString(TransactionForm transactionForm) {
-                return transactionForm.toString();
-            }
+            protected void updateItem(TransactionForm form, boolean empty) {
+                super.updateItem(form, empty);
 
-            @Override
-            public TransactionForm fromString(String string) {
-                throw new IllegalStateException("No editing");
+                setText(null);
+                setGraphic(null);
+                setTooltip(null);
+                setContextMenu(null);
+
+                if(form != null) {
+                    setText(form.toString());
+
+                    if(form.getSigningWallet() != null) {
+                        if(form instanceof InputForm) {
+                            InputForm inputForm = (InputForm)form;
+                            if(inputForm.isWalletTxo()) {
+                                setGraphic(TransactionDiagram.getTxoGlyph());
+                            } else {
+                                setGraphic(TransactionDiagram.getPayjoinGlyph());
+                            }
+                        }
+                        if(form instanceof OutputForm) {
+                            OutputForm outputForm = (OutputForm)form;
+                            if(outputForm.isWalletConsolidation()) {
+                                setGraphic(TransactionDiagram.getConsolidationGlyph());
+                            } else if(outputForm.isWalletChange()) {
+                                setGraphic(TransactionDiagram.getChangeGlyph());
+                            } else {
+                                setGraphic(TransactionDiagram.getPaymentGlyph());
+                            }
+                        }
+                    }
+                }
             }
-        }));
+        });
+
+        txdata.signingWalletProperty().addListener((observable, oldValue, newValue) -> {
+            txtree.refresh();
+        });
 
         txtree.getSelectionModel().selectedItemProperty().addListener((observable, old_val, selectedItem) -> {
             TransactionForm transactionForm = selectedItem.getValue();

src/main/java/com/sparrowwallet/sparrow/transaction/TransactionForm.java

@@ -107,6 +107,10 @@ public abstract class TransactionForm {
         return true;
     }
 
+    public boolean isTransactionFinalized() {
+        return getPsbt() == null || getTransaction().hasScriptSigs() || getTransaction().hasWitnesses();
+    }
+
     public abstract Node getContents() throws IOException;
 
     public abstract TransactionView getView();

src/main/java/com/sparrowwallet/sparrow/ur/Bytewords.java

@@ -1,153 +0,0 @@
-package com.sparrowwallet.sparrow.ur;
-
-import java.io.ByteArrayOutputStream;
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.StringJoiner;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-import java.util.zip.CRC32;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class Bytewords {
-    public static final String BYTEWORDS = "ableacidalsoapexaquaarchatomauntawayaxisbackbaldbarnbeltbetabiasbluebodybragbrewbulbbuzzcalmcashcatschefcityclawcodecolacookcostcruxcurlcuspcyandarkdatadaysdelidicedietdoordowndrawdropdrumdulldutyeacheasyechoedgeepicevenexamexiteyesfactfairfernfigsfilmfishfizzflapflewfluxfoxyfreefrogfuelfundgalagamegeargemsgiftgirlglowgoodgraygrimgurugushgyrohalfhanghardhawkheathelphighhillholyhopehornhutsicedideaidleinchinkyintoirisironitemjadejazzjoinjoltjowljudojugsjumpjunkjurykeepkenokeptkeyskickkilnkingkitekiwiknoblamblavalazyleaflegsliarlimplionlistlogoloudloveluaulucklungmainmanymathmazememomenumeowmildmintmissmonknailnavyneednewsnextnoonnotenumbobeyoboeomitonyxopenovalowlspaidpartpeckplaypluspoempoolposepuffpumapurrquadquizraceramprealredorichroadrockroofrubyruinrunsrustsafesagascarsetssilkskewslotsoapsolosongstubsurfswantacotasktaxitenttiedtimetinytoiltombtoystriptunatwinuglyundouniturgeuservastveryvetovialvibeviewvisavoidvowswallwandwarmwaspwavewaxywebswhatwhenwhizwolfworkyankyawnyellyogayurtzapszerozestzinczonezoom";
-    private static final List<String> bytewordsList;
-    private static final List<String> minimalBytewordsList;
-
-    static {
-        bytewordsList = getBytewords();
-        minimalBytewordsList = getMinimalBytewords();
-    }
-
-    public enum Style {
-        STANDARD, URI, MINIMAL
-    }
-
-    public static int getEncodedLength(int length, Style style) {
-        if(style == Style.STANDARD || style == Style.URI) {
-            return length * 4 + (length - 1);
-        }
-
-        return length * 2;
-    }
-
-    public static String encode(byte[] data, Style style) {
-        if(style == Style.STANDARD) {
-            return encode(data, " ");
-        }
-        if(style == Style.URI) {
-            return encode(data, "-");
-        }
-
-        return encodeMinimal(data);
-    }
-
-    public static byte[] decode(String encoded, Style style) {
-        if(style == Style.STANDARD) {
-            return decode(encoded, " ");
-        }
-        if(style == Style.URI) {
-            return decode(encoded, "-");
-        }
-
-        return decodeMinimal(encoded);
-    }
-
-    private static String encode(byte[] data, String separator) {
-        byte[] dataAndChecksum = appendChecksum(data);
-        List<String> words = IntStream.range(0, dataAndChecksum.length).map(index -> dataAndChecksum[index] & 0xFF).mapToObj(Bytewords::getByteword).collect(Collectors.toList());
-        StringJoiner joiner = new StringJoiner(separator);
-        words.forEach(joiner::add);
-        return joiner.toString();
-    }
-
-    private static String encodeMinimal(byte[] data) {
-        byte[] dataAndChecksum = appendChecksum(data);
-        List<String> words = IntStream.range(0, dataAndChecksum.length).map(index -> dataAndChecksum[index] & 0xFF).mapToObj(Bytewords::getMinimalByteword).collect(Collectors.toList());
-        StringBuilder buffer = new StringBuilder();
-        words.forEach(buffer::append);
-        return buffer.toString();
-    }
-
-    private static byte[] decode(String encoded, String separator) {
-        String[] words = encoded.split(separator);
-        byte[] data = toByteArray(Arrays.stream(words).mapToInt(word -> getBytewords().indexOf(word)));
-        return stripChecksum(data);
-    }
-
-    private static byte[] decodeMinimal(String encoded) {
-        List<String> words = splitStringBySize(encoded, 2);
-        byte[] data = toByteArray(words.stream().mapToInt(word -> getMinimalBytewords().indexOf(word)));
-        return stripChecksum(data);
-    }
-
-    private static byte[] appendChecksum(byte[] data) {
-        CRC32 crc = new CRC32();
-        crc.update(data);
-
-        ByteBuffer checksum = ByteBuffer.allocate(Long.BYTES);
-        checksum.putLong(crc.getValue());
-
-        byte[] result = new byte[data.length + 4];
-        System.arraycopy(data, 0, result, 0, data.length);
-        System.arraycopy(checksum.array(), 4, result, data.length, 4);
-
-        return result;
-    }
-
-    private static byte[] stripChecksum(byte[] dataAndChecksum) {
-        byte[] data = Arrays.copyOfRange(dataAndChecksum, 0, dataAndChecksum.length - 4);
-        byte[] checksum = Arrays.copyOfRange(dataAndChecksum, dataAndChecksum.length - 4, dataAndChecksum.length);
-
-        CRC32 crc = new CRC32();
-        crc.update(data);
-
-        ByteBuffer calculedChecksum = ByteBuffer.allocate(Long.BYTES);
-        calculedChecksum.putLong(crc.getValue());
-        if(!Arrays.equals(Arrays.copyOfRange(calculedChecksum.array(), 4, 8), checksum)) {
-            throw new InvalidChecksumException("Invalid checksum");
-        }
-
-        return data;
-    }
-
-    private static String getByteword(int dataByte) {
-        return bytewordsList.get(dataByte);
-    }
-
-    private static String getMinimalByteword(int dataByte) {
-        return minimalBytewordsList.get(dataByte);
-    }
-
-    private static List<String> getBytewords() {
-        return IntStream.range(0, 256).mapToObj(i -> BYTEWORDS.substring(i * 4, (i * 4) + 4)).collect(Collectors.toList());
-    }
-
-    private static List<String> getMinimalBytewords() {
-        return IntStream.range(0, 256).mapToObj(i -> Character.toString(BYTEWORDS.charAt(i * 4)) + BYTEWORDS.charAt((i * 4) + 3)).collect(Collectors.toList());
-    }
-
-    public static byte[] toByteArray(IntStream stream) {
-        return stream.collect(ByteArrayOutputStream::new, (baos, i) -> baos.write((byte) i),
-                (baos1, baos2) -> baos1.write(baos2.toByteArray(), 0, baos2.size()))
-                .toByteArray();
-    }
-
-    private static List<String> splitStringBySize(String str, int size) {
-        List<String> split = new ArrayList<>();
-        for(int i = 0; i < str.length() / size; i++) {
-            split.add(str.substring(i * size, Math.min((i + 1) * size, str.length())));
-        }
-        return split;
-    }
-
-    public static class InvalidChecksumException extends RuntimeException {
-        public InvalidChecksumException(String message) {
-            super(message);
-        }
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/ResultType.java

@@ -1,5 +0,0 @@
-package com.sparrowwallet.sparrow.ur;
-
-public enum ResultType {
-    SUCCESS, FAILURE;
-}

src/main/java/com/sparrowwallet/sparrow/ur/UR.java

@@ -1,137 +0,0 @@
-package com.sparrowwallet.sparrow.ur;
-
-import co.nstant.in.cbor.CborBuilder;
-import co.nstant.in.cbor.CborDecoder;
-import co.nstant.in.cbor.CborEncoder;
-import co.nstant.in.cbor.CborException;
-import co.nstant.in.cbor.model.ByteString;
-import co.nstant.in.cbor.model.DataItem;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Objects;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class UR {
-    public static final String UR_PREFIX = "ur";
-    public static final String BYTES_TYPE = "bytes";
-    public static final String CRYPTO_PSBT_TYPE = "crypto-psbt";
-
-    private final String type;
-    private final byte[] data;
-
-    public UR(String type, byte[] data) throws InvalidTypeException {
-        if(!isURType(type)) {
-            throw new InvalidTypeException("Invalid UR type: " + type);
-        }
-
-        this.type = type;
-        this.data = data;
-    }
-
-    public String getType() {
-        return type;
-    }
-
-    public byte[] getCbor() {
-        return data;
-    }
-
-    public byte[] toBytes() throws InvalidTypeException, CborException {
-        if(!BYTES_TYPE.equals(getType())) {
-            throw new InvalidTypeException("Not a " + BYTES_TYPE + " type");
-        }
-
-        ByteArrayInputStream bais = new ByteArrayInputStream(getCbor());
-        List<DataItem> dataItems = new CborDecoder(bais).decode();
-        return ((ByteString)dataItems.get(0)).getBytes();
-    }
-
-    public static boolean isURType(String type) {
-        for(char c : type.toCharArray()) {
-            if('a' <= c && c <= 'z') {
-                return true;
-            }
-            if('0' <= c && c <= '9') {
-                return true;
-            }
-            if(c == '-') {
-                return true;
-            }
-        }
-
-        return false;
-    }
-
-    public static UR fromBytes(byte[] data) {
-        try {
-            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            new CborEncoder(baos).encode(new CborBuilder()
-                    .add(data)
-                    .build());
-            byte[] cbor = baos.toByteArray();
-
-            return new UR("bytes", cbor);
-        } catch(InvalidTypeException | CborException e) {
-            return null;
-        }
-    }
-
-    public String toString() {
-        return UREncoder.encode(this);
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if(this == o) {
-            return true;
-        }
-        if(o == null || getClass() != o.getClass()) {
-            return false;
-        }
-        UR ur = (UR) o;
-        return type.equals(ur.type) &&
-                Arrays.equals(data, ur.data);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = Objects.hash(type);
-        result = 31 * result + Arrays.hashCode(data);
-        return result;
-    }
-
-    public static class URException extends Exception {
-        public URException(String message) {
-            super(message);
-        }
-    }
-
-    public static class InvalidTypeException extends URException {
-        public InvalidTypeException(String message) {
-            super(message);
-        }
-    }
-
-    public static class InvalidSchemeException extends URException {
-        public InvalidSchemeException(String message) {
-            super(message);
-        }
-    }
-
-    public static class InvalidPathLengthException extends URException {
-        public InvalidPathLengthException(String message) {
-            super(message);
-        }
-    }
-
-    public static class InvalidSequenceComponentException extends URException {
-        public InvalidSequenceComponentException(String message) {
-            super(message);
-        }
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/URDecoder.java

@@ -1,191 +0,0 @@
-package com.sparrowwallet.sparrow.ur;
-
-import co.nstant.in.cbor.CborException;
-import com.sparrowwallet.sparrow.ur.fountain.FountainDecoder;
-import com.sparrowwallet.sparrow.ur.fountain.FountainEncoder;
-
-import java.util.Arrays;
-import java.util.Set;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class URDecoder {
-    private static final Pattern SEQUENCE_COMPONENT_PATTERN = Pattern.compile("(\\d+)-(\\d+)");
-
-    private final FountainDecoder fountainDecoder;
-
-    private String expectedType;
-    private Result result;
-
-    public URDecoder() {
-        this.fountainDecoder = new FountainDecoder();
-    }
-
-    public int getExpectedPartCount() {
-        return fountainDecoder.getExpectedPartCount();
-    }
-
-    public Set<Integer> getReceivedPartIndexes() {
-        return fountainDecoder.getRecievedPartIndexes();
-    }
-
-    public Set<Integer> getLastPartIndexes() {
-        return fountainDecoder.getLastPartIndexes();
-    }
-
-    public int getProcessedPartsCount() {
-        return fountainDecoder.getProcessedPartsCount();
-    }
-
-    public double getEstimatedPercentComplete() {
-        return fountainDecoder.getEstimatedPercentComplete();
-    }
-
-    public Result getResult() {
-        return result;
-    }
-
-    public static UR decode(String string) throws UR.URException {
-        ParsedURString parsedURString = parse(string);
-
-        if(parsedURString.components.length < 1) {
-            throw new UR.InvalidPathLengthException("Invalid path length");
-        }
-
-        String body = parsedURString.components[0];
-        return decode(parsedURString.type, body);
-    }
-
-    public static UR decode(String type, String body) throws UR.InvalidTypeException {
-        byte[] cbor = Bytewords.decode(body, Bytewords.Style.MINIMAL);
-        return new UR(type, cbor);
-    }
-
-    public boolean receivePart(String string) {
-        try {
-            // Don't process the part if we're already done
-            if(getResult() != null) {
-                return false;
-            }
-
-            // Don't continue if this part doesn't validate
-            ParsedURString parsedURString = parse(string);
-            if(!validatePart(parsedURString.type)) {
-                return false;
-            }
-
-            // If this is a single-part UR then we're done
-            if(parsedURString.components.length == 1) {
-                String body = parsedURString.components[0];
-                result = new Result(ResultType.SUCCESS, decode(parsedURString.type, body), null);
-                return true;
-            }
-
-            // Multi-part URs must have two path components: seq/fragment
-            if(parsedURString.components.length != 2) {
-                throw new UR.InvalidPathLengthException("Invalid path length");
-            }
-
-            String seq = parsedURString.components[0];
-            String fragment = parsedURString.components[1];
-
-            // Parse the sequence component and the fragment, and
-            // make sure they agree.
-            Matcher matcher = SEQUENCE_COMPONENT_PATTERN.matcher(seq);
-            if(matcher.matches()) {
-                int seqNum = Integer.parseInt(matcher.group(1));
-                int seqLen = Integer.parseInt(matcher.group(2));
-
-                byte[] cbor = Bytewords.decode(fragment, Bytewords.Style.MINIMAL);
-                FountainEncoder.Part part = FountainEncoder.Part.fromCborBytes(cbor);
-
-                if(seqNum != part.getSeqNum() || seqLen != part.getSeqLen()) {
-                    return false;
-                }
-
-                if(!fountainDecoder.receivePart(part)) {
-                    return false;
-                }
-
-                if(fountainDecoder.getResult() == null) {
-                    //Not done yet
-                } else if(fountainDecoder.getResult().type == ResultType.SUCCESS) {
-                    result = new Result(ResultType.SUCCESS, new UR(parsedURString.type, fountainDecoder.getResult().data), null);
-                } else if(fountainDecoder.getResult().type == ResultType.FAILURE) {
-                    result = new Result(ResultType.FAILURE, null, fountainDecoder.getResult().error);
-                }
-
-                return true;
-            } else {
-                throw new UR.InvalidSequenceComponentException("Invalid sequence " + seq);
-            }
-        } catch(UR.URException | CborException e) {
-            return false;
-        }
-    }
-
-    private boolean validatePart(String type) {
-        if(expectedType == null) {
-            if(!UR.isURType(type)) {
-                return false;
-            }
-            expectedType = type;
-        } else {
-            return expectedType.equals(type);
-        }
-
-        return true;
-    }
-
-    static ParsedURString parse(String string) throws UR.URException {
-        // Don't consider case
-        String lowercased = string.toLowerCase();
-
-        // Validate URI scheme
-        if(!lowercased.startsWith("ur:")) {
-            throw new UR.InvalidSchemeException("Invalid scheme");
-        }
-        String path = lowercased.substring(3);
-
-        // Split the remainder into path components
-        String[] components = path.split("/");
-
-        // Make sure there are at least two path components
-        if(components.length <= 1) {
-            throw new UR.InvalidPathLengthException("Invalid path length");
-        }
-
-        // Validate the type
-        String type = components[0];
-        if(!UR.isURType(type)) {
-            throw new UR.InvalidTypeException("Invalid type: " + type);
-        }
-
-        return new ParsedURString(type, Arrays.copyOfRange(components, 1, components.length));
-    }
-
-    private static class ParsedURString {
-        public final String type;
-        public final String[] components;
-
-        public ParsedURString(String type, String[] components) {
-            this.type = type;
-            this.components = components;
-        }
-    }
-
-    public static class Result {
-        public final ResultType type;
-        public final UR ur;
-        public final String error;
-
-        public Result(ResultType type, UR ur, String error) {
-            this.type = type;
-            this.ur = ur;
-            this.error = error;
-        }
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/UREncoder.java

@@ -1,72 +0,0 @@
-package com.sparrowwallet.sparrow.ur;
-
-import com.sparrowwallet.sparrow.ur.fountain.FountainEncoder;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.StringJoiner;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class UREncoder {
-    private final UR ur;
-    private final FountainEncoder fountainEncoder;
-
-    public UREncoder(UR ur, int maxFragmentLen, int minFragmentLen, long firstSeqNum) {
-        this.ur = ur;
-        this.fountainEncoder = new FountainEncoder(ur.getCbor(), maxFragmentLen, minFragmentLen, firstSeqNum);
-    }
-
-    public boolean isComplete() {
-        return fountainEncoder.isComplete();
-    }
-
-    public boolean isSinglePart() {
-        return fountainEncoder.isSinglePart();
-    }
-
-    public String nextPart() {
-        FountainEncoder.Part part = fountainEncoder.nextPart();
-        if(isSinglePart()) {
-            return encode(ur);
-        } else {
-            return encodePart(ur.getType(), part);
-        }
-    }
-
-    public long getSeqNum() {
-        return fountainEncoder.getSeqNum();
-    }
-
-    public int getSeqLen() {
-        return fountainEncoder.getSeqLen();
-    }
-
-    public List<Integer> getPartIndexes() {
-        return fountainEncoder.getPartIndexes();
-    }
-
-    public static String encode(UR ur) {
-        String encoded = Bytewords.encode(ur.getCbor(), Bytewords.Style.MINIMAL);
-        return encodeUR(ur.getType(), encoded);
-    }
-
-    private static String encodeUR(String... pathComponents) {
-        return encodeURI(UR.UR_PREFIX, pathComponents);
-    }
-
-    private static String encodeURI(String scheme, String... pathComponents) {
-        StringJoiner joiner = new StringJoiner("/");
-        Arrays.stream(pathComponents).forEach(joiner::add);
-        String path = joiner.toString();
-
-        return scheme + ":" + path;
-    }
-
-    private static String encodePart(String type, FountainEncoder.Part part) {
-        String seq = part.getSeqNum() + "-" + part.getSeqLen();
-        String body = Bytewords.encode(part.toCborBytes(), Bytewords.Style.MINIMAL);
-        return encodeUR(type, seq, body);
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/fountain/FountainDecoder.java

@@ -1,281 +0,0 @@
-package com.sparrowwallet.sparrow.ur.fountain;
-
-import com.sparrowwallet.sparrow.ur.ResultType;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.io.ByteArrayOutputStream;
-import java.util.*;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-import java.util.zip.CRC32;
-
-import static com.sparrowwallet.sparrow.ur.fountain.FountainUtils.chooseFragments;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class FountainDecoder {
-    private static final Logger log = LoggerFactory.getLogger(FountainDecoder.class);
-
-    private final Set<Integer> recievedPartIndexes = new TreeSet<>();
-    private Set<Integer> lastPartIndexes;
-    private int processedPartsCount = 0;
-    private Result result;
-    private long checksum;
-
-    private Set<Integer> expectedPartIndexes;
-    private int expectedFragmentLen;
-    private int expectedMessageLen;
-    private long expectedChecksum;
-
-    private final Map<List<Integer>, Part> simpleParts = new HashMap<>();
-    private Map<List<Integer>, Part> mixedParts = new HashMap<>();
-    private final List<Part> queuedParts = new ArrayList<>();
-
-    public int getExpectedPartCount() {
-        return expectedPartIndexes.size();
-    }
-
-    public Set<Integer> getRecievedPartIndexes() {
-        return recievedPartIndexes;
-    }
-
-    public Set<Integer> getLastPartIndexes() {
-        return lastPartIndexes;
-    }
-
-    public int getProcessedPartsCount() {
-        return processedPartsCount;
-    }
-
-    public double getEstimatedPercentComplete() {
-        double estimatedInputParts = (double)getExpectedPartCount() * 1.75;
-        return Math.min(0.99, (double)processedPartsCount / estimatedInputParts);
-    }
-
-    public Result getResult() {
-        return result;
-    }
-
-    private static class Part {
-        private final List<Integer> partIndexes;
-        private final byte[] data;
-
-        private int getIndex() {
-            return partIndexes.get(0);
-        }
-
-        Part(FountainEncoder.Part part) {
-            this.partIndexes = chooseFragments(part.getSeqNum(), part.getSeqLen(), part.getChecksum());
-            this.data = part.getData();
-        }
-
-        Part(List<Integer> indexes, byte[] data) {
-            this.partIndexes = indexes;
-            this.data = data;
-        }
-
-        public boolean isSimple() {
-            return partIndexes.size() == 1;
-        }
-    }
-
-    public static class Result {
-        public final ResultType type;
-        public final byte[] data;
-        public final String error;
-
-        public Result(ResultType type, byte[] data, String error) {
-            this.type = type;
-            this.data = data;
-            this.error = error;
-        }
-    }
-
-    public boolean receivePart(FountainEncoder.Part encoderPart) {
-        // Don't process the part if we're already done
-        if(result != null) {
-            return false;
-        }
-
-        // Don't continue if this part doesn't validate
-        if(!validatePart(encoderPart)) {
-             return false;
-        }
-
-        // Add this part to the queue
-        Part part = new Part(encoderPart);
-        lastPartIndexes = new HashSet<>(part.partIndexes);
-        enqueue(part);
-
-        // Process the queue until we're done or the queue is empty
-        while(result == null && !queuedParts.isEmpty()) {
-            processQueueItem();
-        }
-
-        // Keep track of how many parts we've processed
-        processedPartsCount += 1;
-        //printPartEnd();
-
-        return true;
-    }
-
-    private void enqueue(Part part) {
-        queuedParts.add(part);
-    }
-
-    private void printPartEnd() {
-        int percent = (int)Math.round(getEstimatedPercentComplete() * 100);
-        log.debug("processed: " + processedPartsCount + " expected: " + getExpectedPartCount() + " received: " + recievedPartIndexes.size() + " percent: " + percent + "%");
-    }
-
-    private void printPart(Part part) {
-        List<Integer> sorted = part.partIndexes.stream().sorted().collect(Collectors.toList());
-        log.debug("part indexes: " + sorted);
-    }
-
-    private void printState() {
-        List<Integer> sortedReceived = recievedPartIndexes.stream().sorted().collect(Collectors.toList());
-        List<List<Integer>> mixed = mixedParts.keySet().stream().map(list -> {
-            list.sort(Comparator.naturalOrder());
-            return list;
-        }).collect(Collectors.toList());
-
-        log.debug("parts: " + getExpectedPartCount() + ", received: " + sortedReceived + ", mixed: " + mixed + ", queued: " + queuedParts.size() + ", result: " + result);
-    }
-
-    private void processQueueItem() {
-        Part part = queuedParts.remove(0);
-
-        //printPart(part);
-
-        if(part.isSimple()) {
-            processSimplePart(part);
-        } else {
-            processMixedPart(part);
-        }
-
-        //printState();
-    }
-
-    private void reduceMixed(Part by) {
-        // Reduce all the current mixed parts by the given part
-        List<Part> reducedParts = mixedParts.values().stream().map(part -> reducePart(part, by)).collect(Collectors.toList());
-
-        // Collect all the remaining mixed parts
-        Map<List<Integer>, Part> newMixed = new HashMap<>();
-        reducedParts.forEach(reducedPart -> {
-            // If this reduced part is now simple
-            if(reducedPart.isSimple()) {
-                // Add it to the queue
-                enqueue(reducedPart);
-            } else {
-                // Otherwise, add it to the list of current mixed parts
-                newMixed.put(reducedPart.partIndexes, reducedPart);
-            }
-        });
-
-        mixedParts = newMixed;
-    }
-
-    // Reduce part `a` by part `b`
-    private Part reducePart(Part a, Part b) {
-        // If the fragments mixed into `b` are a strict (proper) subset of those in `a`...
-        if(a.partIndexes.containsAll(b.partIndexes)) {
-            // The new fragments in the revised part are `a` - `b`.
-            List<Integer> newIndexes = new ArrayList<>(a.partIndexes);
-            newIndexes.removeAll(b.partIndexes);
-
-            // The new data in the revised part are `a` XOR `b`
-            byte[] newdata = FountainEncoder.xor(a.data, b.data);
-            return new Part(newIndexes, newdata);
-        } else {
-            // `a` is not reducable by `b`, so return a
-            return a;
-        }
-    }
-
-    private void processSimplePart(Part part) {
-        // Don't process duplicate parts
-        Integer fragmentIndex = part.partIndexes.get(0);
-        if(recievedPartIndexes.contains(fragmentIndex)) {
-            return;
-        }
-
-        // Record this part
-        simpleParts.put(part.partIndexes, part);
-        recievedPartIndexes.add(fragmentIndex);
-
-        // If we've received all the parts
-        if(recievedPartIndexes.equals(expectedPartIndexes)) {
-            // Reassemble the message from its fragments
-            List<Part> sortedParts = simpleParts.values().stream().sorted(Comparator.comparingInt(Part::getIndex)).collect(Collectors.toList());
-            List<byte[]> fragments = sortedParts.stream().map(part1 -> part1.data).collect(Collectors.toList());
-            byte[] message = joinFragments(fragments, expectedMessageLen);
-
-            // Verify the message checksum and note success or failure
-            CRC32 crc32 = new CRC32();
-            crc32.update(message);
-            checksum = crc32.getValue();
-
-            if(checksum == expectedChecksum) {
-                result = new Result(ResultType.SUCCESS, message, null);
-            } else {
-                result = new Result(ResultType.FAILURE, null, "Invalid checksum");
-            }
-        } else {
-            // Reduce all the mixed parts by this part
-            reduceMixed(part);
-        }
-    }
-
-    private void processMixedPart(Part part) {
-        // Don't process duplicate parts
-        if(mixedParts.containsKey(part.partIndexes)) {
-            return;
-        }
-
-        // Reduce this part by all the others
-        List<Part> allParts = new ArrayList<>(simpleParts.values());
-        allParts.addAll(mixedParts.values());
-        Part p = allParts.stream().reduce(part, this::reducePart);
-
-        // If the part is now simple
-        if(p.isSimple()) {
-            // Add it to the queue
-            enqueue(p);
-        } else {
-            // Reduce all the mixed parts by this one
-            reduceMixed(p);
-            // Record this new mixed part
-            mixedParts.put(p.partIndexes, p);
-        }
-    }
-
-    private boolean validatePart(FountainEncoder.Part part) {
-        // If this is the first part we've seen
-        if(expectedPartIndexes == null) {
-            // Record the things that all the other parts we see will have to match to be valid.
-            expectedPartIndexes = IntStream.range(0, part.getSeqLen()).boxed().collect(Collectors.toSet());
-            expectedMessageLen = part.getMessageLen();
-            expectedChecksum = part.getChecksum();
-            expectedFragmentLen = part.getData().length;
-
-            return true;
-        } else {
-            return getExpectedPartCount() == part.getSeqLen() && expectedMessageLen == part.getMessageLen() && expectedChecksum == part.getChecksum() && expectedFragmentLen == part.getData().length;
-        }
-    }
-
-    static byte[] joinFragments(List<byte[]> fragments, int messageLen) {
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        fragments.forEach(baos::writeBytes);
-        byte[] message = baos.toByteArray();
-
-        byte[] unpaddedMessage = new byte[messageLen];
-        System.arraycopy(message, 0, unpaddedMessage, 0, messageLen);
-
-        return unpaddedMessage;
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/fountain/FountainEncoder.java

@@ -1,185 +0,0 @@
-package com.sparrowwallet.sparrow.ur.fountain;
-
-import co.nstant.in.cbor.CborBuilder;
-import co.nstant.in.cbor.CborDecoder;
-import co.nstant.in.cbor.CborEncoder;
-import co.nstant.in.cbor.CborException;
-import co.nstant.in.cbor.model.Array;
-import co.nstant.in.cbor.model.ByteString;
-import co.nstant.in.cbor.model.DataItem;
-import co.nstant.in.cbor.model.UnsignedInteger;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.zip.CRC32;
-
-import static com.sparrowwallet.sparrow.ur.fountain.FountainUtils.chooseFragments;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class FountainEncoder {
-    private final int messageLen;
-    private final long checksum;
-    private final int fragmentLen;
-    private final List<byte[]> fragments;
-    private final int seqLen;
-    private List<Integer> partIndexes;
-    private long seqNum;
-
-    public FountainEncoder(byte[] message, int maxFragmentLen, int minFragmentLen, long firstSeqNum) {
-        if(message.length >= Integer.MAX_VALUE) {
-            throw new IllegalArgumentException("Message too long");
-        }
-
-        this.messageLen = message.length;
-
-        CRC32 crc32 = new CRC32();
-        crc32.update(message);
-        this.checksum = crc32.getValue();
-
-        this.fragmentLen = findNominalFragmentLength(messageLen, minFragmentLen, maxFragmentLen);
-        this.fragments = partitionMessage(message, fragmentLen);
-        this.seqLen = fragments.size();
-        this.seqNum = firstSeqNum;
-    }
-
-    public Part nextPart() {
-        seqNum += 1;
-        partIndexes = chooseFragments(seqNum, seqLen, checksum);
-        byte[] mixed = mix(partIndexes);
-        return new Part(seqNum, seqLen, messageLen, checksum, mixed);
-    }
-
-    private byte[] mix(List<Integer> partIndexes) {
-        return partIndexes.stream().reduce(new byte[fragmentLen], (result, index) -> xor(fragments.get(index), result), FountainEncoder::xor);
-    }
-
-    public static byte[] xor(byte[] a, byte[] b) {
-        byte[] result = new byte[a.length];
-        for (int i = 0; i < result.length; i++) {
-            result[i] = (byte) (((int) a[i]) ^ ((int) b[i]));
-        }
-
-        return result;
-    }
-
-    public boolean isComplete() {
-        return seqNum >= seqLen;
-    }
-
-    public boolean isSinglePart() {
-        return seqLen == 1;
-    }
-
-    public long getSeqNum() {
-        return seqNum;
-    }
-
-    public int getSeqLen() {
-        return seqLen;
-    }
-
-    public List<Integer> getPartIndexes() {
-        return partIndexes;
-    }
-
-    static List<byte[]> partitionMessage(byte[] message, int fragmentLen) {
-        int fragmentCount = (int)Math.ceil(message.length / (double)fragmentLen);
-        List<byte[]> fragments = new ArrayList<>();
-
-        int start = 0;
-        for(int i = 0; i < fragmentCount; i++) {
-            fragments.add(Arrays.copyOfRange(message, start, start + fragmentLen));
-            start += fragmentLen;
-        }
-
-        return fragments;
-    }
-
-    static int findNominalFragmentLength(int messageLen, int minFragmentLen, int maxFragmentLen) {
-        int maxFragmentCount = messageLen / minFragmentLen;
-        int fragmentLen = 0;
-        for(int fragmentCount = 1; fragmentCount <= maxFragmentCount; fragmentCount++) {
-            fragmentLen = (int)Math.ceil((double)messageLen / (double)fragmentCount);
-            if(fragmentLen <= maxFragmentLen) {
-                break;
-            }
-        }
-
-        return fragmentLen;
-    }
-
-    public static class Part {
-        private final long seqNum;
-        private final int seqLen;
-        private final int messageLen;
-        private final long checksum;
-        private final byte[] data;
-
-        public Part(long seqNum, int seqLen, int messageLen, long checksum, byte[] data) {
-            this.seqNum = seqNum;
-            this.seqLen = seqLen;
-            this.messageLen = messageLen;
-            this.checksum = checksum;
-            this.data = data;
-        }
-
-        public long getSeqNum() {
-            return seqNum;
-        }
-
-        public int getSeqLen() {
-            return seqLen;
-        }
-
-        public int getMessageLen() {
-            return messageLen;
-        }
-
-        public long getChecksum() {
-            return checksum;
-        }
-
-        public byte[] getData() {
-            return data;
-        }
-
-        public byte[] toCborBytes() {
-            try {
-                ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                new CborEncoder(baos).encode(new CborBuilder()
-                        .addArray()
-                        .add(new UnsignedInteger(seqNum))
-                        .add(new UnsignedInteger(seqLen))
-                        .add(new UnsignedInteger(messageLen))
-                        .add(new UnsignedInteger(checksum))
-                        .add(data)
-                        .end()
-                        .build());
-
-                return baos.toByteArray();
-            } catch(Exception e) {
-                throw new RuntimeException(e);
-            }
-        }
-
-        public static Part fromCborBytes(byte[] cborData) throws CborException {
-            ByteArrayInputStream bais = new ByteArrayInputStream(cborData);
-            List<DataItem> arrayDataItems = new CborDecoder(bais).decode();
-            Array array = (Array)arrayDataItems.get(0);
-            List<DataItem> dataItems = array.getDataItems();
-
-            UnsignedInteger seqNum = (UnsignedInteger)dataItems.get(0);
-            UnsignedInteger seqLen = (UnsignedInteger)dataItems.get(1);
-            UnsignedInteger messageLen = (UnsignedInteger)dataItems.get(2);
-            UnsignedInteger checksum = (UnsignedInteger)dataItems.get(3);
-            ByteString data = (ByteString)dataItems.get(4);
-
-            return new Part(seqNum.getValue().longValue(), seqLen.getValue().intValue(), messageLen.getValue().intValue(), checksum.getValue().longValue(), data.getBytes());
-        }
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/fountain/FountainUtils.java

@@ -1,50 +0,0 @@
-package com.sparrowwallet.sparrow.ur.fountain;
-
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-
-/**
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class FountainUtils {
-    static List<Integer> chooseFragments(long seqNum, int seqLen, long checkSum) {
-        // The first `seqLen` parts are the "pure" fragments, not mixed with any
-        // others. This means that if you only generate the first `seqLen` parts,
-        // then you have all the parts you need to decode the message.
-        if(seqNum <= seqLen) {
-            return List.of((int)seqNum - 1);
-        } else {
-            ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES * 2);
-            buffer.putInt((int)(seqNum));
-            buffer.putInt((int)(checkSum));
-
-            RandomXoshiro256StarStar rng = new RandomXoshiro256StarStar(buffer.array());
-            int degree = chooseDegree(seqLen, rng);
-            List<Integer> indexes = IntStream.range(0, seqLen).boxed().collect(Collectors.toList());
-            List<Integer> shuffledIndexes = shuffled(indexes, rng);
-            return new ArrayList<>(shuffledIndexes.subList(0, degree));
-        }
-    }
-
-    static int chooseDegree(int seqLen, RandomXoshiro256StarStar rng) {
-        List<Double> degreeProbabilties = IntStream.range(1, seqLen + 1).mapToObj(i -> 1 / (double)i).collect(Collectors.toList());
-        RandomSampler randomSampler = new RandomSampler(degreeProbabilties);
-        return randomSampler.next(rng) + 1;
-    }
-
-    static List<Integer> shuffled(List<Integer> indexes, RandomXoshiro256StarStar rng) {
-        List<Integer> remaining = new ArrayList<>(indexes);
-        List<Integer> shuffled = new ArrayList<>(indexes.size());
-
-        while(!remaining.isEmpty()) {
-            int index = rng.nextInt(0, remaining.size());
-            Integer item = remaining.remove(index);
-            shuffled.add(item);
-        }
-
-        return shuffled;
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/fountain/RandomSampler.java

@@ -1,84 +0,0 @@
-package com.sparrowwallet.sparrow.ur.fountain;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-import java.util.stream.Collectors;
-
-/**
- * Random-number sampling using the Walker-Vose alias method,
- * as described by Keith Schwarz (2011)
- * http://www.keithschwarz.com/darts-dice-coins
- *
- * Based on C implementation:
- * https://jugit.fz-juelich.de/mlz/ransampl
- *
- * Ported from https://github.com/BlockchainCommons/URKit
- */
-public class RandomSampler {
-    /* The probability and alias tables. */
-    private final double[] probs;
-    private final int[] aliases;
-
-    public RandomSampler(List<Double> probabilities) {
-        if(probabilities.stream().anyMatch(prob -> prob < 0)) {
-            throw new IllegalArgumentException("Probabilties must be > 0");
-        }
-
-        // Normalize given probabilities
-        double sum = probabilities.stream().reduce(0d, Double::sum);
-
-        int n = probabilities.size();
-        List<Double> P = probabilities.stream().map(prob -> prob * (double)n / sum).collect(Collectors.toList());
-
-        List<Integer> S = new ArrayList<>();
-        List<Integer> L = new ArrayList<>();
-
-        // Set separate index lists for small and large probabilities:
-        for(int i = n - 1; i >= 0; i--) {
-            // at variance from Schwarz, we reverse the index order
-            if(P.get(i) < 1d) {
-                S.add(i);
-            } else {
-                L.add(i);
-            }
-        }
-
-        // Work through index lists
-        double[] probs = new double[n];
-        int[] aliases = new int[n];
-
-        while(!S.isEmpty() && !L.isEmpty()) {
-            int a = S.remove(S.size() - 1);
-            int g = L.remove(L.size() - 1);
-            probs[a] = P.get(a);
-            aliases[a] = g;
-            P.set(g, P.get(g) + P.get(a) - 1);
-            if(P.get(g) < 1) {
-                S.add(g);
-            } else {
-                L.add(g);
-            }
-        }
-
-        while(!L.isEmpty()) {
-            probs[L.remove(L.size() - 1)] = 1;
-        }
-
-        while(!S.isEmpty()) {
-            // can only happen through numeric instability
-            probs[S.remove(S.size() - 1)] = 1;
-        }
-
-        this.probs = probs;
-        this.aliases = aliases;
-    }
-
-    public int next(Random random) {
-        double r1 = random.nextDouble();
-        double r2 = random.nextDouble();
-        int n = probs.length;
-        int i = (int)((double)n * r1);
-        return r2 < probs[i] ? i : aliases[i];
-    }
-}

src/main/java/com/sparrowwallet/sparrow/ur/fountain/RandomXoshiro256StarStar.java

@@ -1,241 +0,0 @@
-package com.sparrowwallet.sparrow.ur.fountain;
-
-/*
- * To the extent possible under law, the author has dedicated all copyright
- * and related and neighboring rights to this software to the public domain
- * worldwide. This software is distributed without any warranty.
- *
- * See <http://creativecommons.org/publicdomain/zero/1.0/>
- */
-
-import com.sparrowwallet.drongo.protocol.Sha256Hash;
-
-import java.nio.charset.StandardCharsets;
-import java.util.Random;
-import java.util.concurrent.atomic.AtomicLong;
-
-/**
- * Implementation of Random based on the xoshiro256** RNG. No-dependencies
- * Java port of the <a href="http://xoshiro.di.unimi.it/xoshiro256starstar.c">original C code</a>,
- * which is public domain. This Java port is similarly dedicated to the public
- * domain.
- * <p>
- * Individual instances are not thread-safe. Each thread must have its own
- * instance which is not shared.
- *
- * @author David Blackman and Sebastiano Vigna &lt;vigna@acm.org> (original C code)
- * @author Una Thompson &lt;una@unascribed.com> (Java port)
- * @see <a href="http://xoshiro.di.unimi.it/">http://xoshiro.di.unimi.it/</a>
- */
-public class RandomXoshiro256StarStar extends Random {
-    private static final long serialVersionUID = -2837799889588687855L;
-
-    private static final AtomicLong uniq = new AtomicLong(System.nanoTime());
-
-    private static final long nextUniq() {
-        return splitmix64_2(uniq.addAndGet(SPLITMIX1_MAGIC));
-    }
-
-    private long seed;
-
-    public RandomXoshiro256StarStar() {
-        this(System.nanoTime() ^ nextUniq());
-    }
-
-    public RandomXoshiro256StarStar(long seed) {
-        super(seed);
-        // super will call setSeed
-    }
-
-    public RandomXoshiro256StarStar(String seed) {
-        this(seed.getBytes(StandardCharsets.UTF_8));
-    }
-
-    public RandomXoshiro256StarStar(byte[] seed) {
-        this(Sha256Hash.of(seed));
-    }
-
-    public RandomXoshiro256StarStar(Sha256Hash digest) {
-        long[] s = new long[4];
-        byte[] digestBytes = digest.getBytes();
-
-        for(int i = 0; i < 4; i++) {
-            int o = i * 8;
-            long v = 0L;
-            for(int n = 0; n < 8; n++) {
-                v = v << 8;
-                v |= digestBytes[o + n] & 0xFF;
-            }
-            s[i] = v;
-        }
-
-        setState(s[0], s[1], s[2], s[3]);
-    }
-
-    public RandomXoshiro256StarStar(long s1, long s2, long s3, long s4) {
-        setState(s1, s2, s3, s4);
-    }
-
-    // used to "stretch" seeds into a full 256-bit state; also makes
-    // it safe to pass in zero as a seed
-    ////
-    // what generator is used here is unimportant, as long as it's
-    // from a different family, but splitmix64 happens to be an
-    // incredibly simple high-quality generator of a completely
-    // different family (and is recommended by the xoshiro authors)
-
-    private static final long SPLITMIX1_MAGIC = 0x9E3779B97F4A7C15L;
-
-    private static long splitmix64_1(long x) {
-        return (x + SPLITMIX1_MAGIC);
-    }
-
-    private static long splitmix64_2(long z) {
-        z = (z ^ (z >> 30)) * 0xBF58476D1CE4E5B9L;
-        z = (z ^ (z >> 27)) * 0x94D049BB133111EBL;
-        return z ^ (z >> 31);
-    }
-
-    @Override
-    public void setSeed(long seed) {
-        this.seed = seed;
-
-        // update haveNextNextGaussian flag in super
-        super.setSeed(seed);
-        long sms = splitmix64_1(seed);
-        s0 = splitmix64_2(sms);
-        sms = splitmix64_1(sms);
-        s1 = splitmix64_2(sms);
-        sms = splitmix64_1(sms);
-        s2 = splitmix64_2(sms);
-        sms = splitmix64_1(sms);
-        s3 = splitmix64_2(sms);
-    }
-
-    public void setState(long s0, long s1, long s2, long s4) {
-        if(s0 == 0 && s1 == 0 && s2 == 0 && s4 == 0) {
-            throw new IllegalArgumentException("xoshiro256** state cannot be all zeroes");
-        }
-        this.s0 = s0;
-        this.s1 = s1;
-        this.s2 = s2;
-        this.s3 = s4;
-    }
-
-    // not called, implemented instead of just throwing for completeness
-    @Override
-    protected int next(int bits) {
-        return (int) (nextLong() & ((1L << bits) - 1));
-    }
-
-    @Override
-    public int nextInt() {
-        return (int) nextLong();
-    }
-
-    @Override
-    public int nextInt(int bound) {
-        return (int) nextLong(bound);
-    }
-
-    public long nextLong(long bound) {
-        if(bound <= 0) {
-            throw new IllegalArgumentException("bound must be positive");
-        }
-        // clear sign bit for positive-only, modulo to bound
-        return (nextLong() & Long.MAX_VALUE) % bound;
-    }
-
-    @Override
-    public double nextDouble() {
-        return (nextLong() >>> 11) * 0x1.0P-53;
-    }
-
-    @Override
-    public float nextFloat() {
-        return (nextLong() >>> 40) * 0x1.0P-24f;
-    }
-
-    @Override
-    public boolean nextBoolean() {
-        return (nextLong() & 1) != 0;
-    }
-
-    @Override
-    public void nextBytes(byte[] buf) {
-        nextBytes(buf, 0, buf.length);
-    }
-
-    public void nextBytes(byte[] buf, int ofs, int len) {
-        if(ofs < 0) {
-            throw new ArrayIndexOutOfBoundsException("Offset " + ofs + " is negative");
-        }
-        if(ofs >= buf.length) {
-            throw new ArrayIndexOutOfBoundsException("Offset " + ofs + " is greater than buffer length");
-        }
-        if(ofs + len > buf.length) {
-            throw new ArrayIndexOutOfBoundsException("Length " + len + " with offset " + ofs + " is past end of buffer");
-        }
-        int j = 8;
-        long l = 0;
-        for(int i = ofs; i < ofs + len; i++) {
-            if(j >= 8) {
-                l = nextLong();
-                j = 0;
-            }
-            buf[i] = (byte) (l & 0xFF);
-            l = l >>> 8L;
-            j++;
-        }
-    }
-
-    public void nextData(byte[] data) {
-        for(int i = 0; i < data.length; i++) {
-            data[i] = (byte)(nextInt(0, 256) & 0xFF);
-        }
-    }
-
-    public int nextInt(int lowerBound, int count) {
-        double next = nextDouble();
-        double dou = (next * count);
-        return (int)(dou) + lowerBound;
-    }
-
-	/* This is xoshiro256** 1.0, our all-purpose, rock-solid generator. It has
-	   excellent (sub-ns) speed, a state (256 bits) that is large enough for
-	   any parallel application, and it passes all tests we are aware of.
-
-	   For generating just floating-point numbers, xoshiro256+ is even faster.
-
-	   The state must be seeded so that it is not everywhere zero. If you have
-	   a 64-bit seed, we suggest to seed a splitmix64 generator and use its
-	   output to fill s. */
-
-    private static long rotl(long x, int k) {
-        return (x << k) | (x >>> (64 - k));
-    }
-
-
-    private long s0;
-    private long s1;
-    private long s2;
-    private long s3;
-
-    @Override
-    public long nextLong() {
-        long result_starstar = rotl(s1 * 5, 7) * 9;
-
-        long t = s1 << 17;
-
-        s2 ^= s0;
-        s3 ^= s1;
-        s1 ^= s2;
-        s0 ^= s3;
-
-        s2 ^= t;
-
-        s3 = rotl(s3, 45);
-
-        return result_starstar;
-    }
-}

src/main/java/com/sparrowwallet/sparrow/wallet/Entry.java

@@ -1,5 +1,6 @@
 package com.sparrowwallet.sparrow.wallet;
 
+import com.sparrowwallet.drongo.wallet.Wallet;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
@@ -7,19 +8,26 @@ import javafx.collections.ObservableList;
 import java.util.List;
 
 public abstract class Entry {
+    private final Wallet wallet;
     private final SimpleStringProperty labelProperty;
     private final ObservableList<Entry> children;
 
-    public Entry(String label, List<Entry> entries) {
+    public Entry(Wallet wallet, String label, List<Entry> entries) {
+        this.wallet = wallet;
         this.labelProperty = new SimpleStringProperty(this, "label", label);
         this.children = FXCollections.observableList(entries);
     }
 
-    public Entry(SimpleStringProperty labelProperty, ObservableList<Entry> children) {
+    public Entry(Wallet wallet, SimpleStringProperty labelProperty, ObservableList<Entry> children) {
+        this.wallet = wallet;
         this.labelProperty = labelProperty;
         this.children = children;
     }
 
+    public Wallet getWallet() {
+        return wallet;
+    }
+
     public String getLabel() {
         return labelProperty.get();
     }

src/main/java/com/sparrowwallet/sparrow/wallet/FeeRatesSelection.java

@@ -0,0 +1,20 @@
+package com.sparrowwallet.sparrow.wallet;
+
+public enum FeeRatesSelection {
+    BLOCK_TARGET("Block Target"), MEMPOOL_SIZE("Mempool Size");
+
+    private final String name;
+
+    private FeeRatesSelection(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/wallet/HashIndexEntry.java

@@ -13,14 +13,12 @@ import java.util.List;
 import java.util.Objects;
 
 public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry> {
-    private final Wallet wallet;
     private final BlockTransactionHashIndex hashIndex;
     private final Type type;
     private final KeyPurpose keyPurpose;
 
     public HashIndexEntry(Wallet wallet, BlockTransactionHashIndex hashIndex, Type type, KeyPurpose keyPurpose) {
-        super(hashIndex.getLabel(), hashIndex.getSpentBy() != null ? List.of(new HashIndexEntry(wallet, hashIndex.getSpentBy(), Type.INPUT, keyPurpose)) : Collections.emptyList());
-        this.wallet = wallet;
+        super(wallet, hashIndex.getLabel(), hashIndex.getSpentBy() != null ? List.of(new HashIndexEntry(wallet, hashIndex.getSpentBy(), Type.INPUT, keyPurpose)) : Collections.emptyList());
         this.hashIndex = hashIndex;
         this.type = type;
         this.keyPurpose = keyPurpose;
@@ -31,10 +29,6 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
         });
     }
 
-    public Wallet getWallet() {
-        return wallet;
-    }
-
     public BlockTransactionHashIndex getHashIndex() {
         return hashIndex;
     }
@@ -48,7 +42,7 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
     }
 
     public BlockTransaction getBlockTransaction() {
-        return wallet.getTransactions().get(hashIndex.getHash());
+        return getWallet().getTransactions().get(hashIndex.getHash());
     }
 
     public String getDescription() {
@@ -63,7 +57,7 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
     }
 
     public boolean isSpendable() {
-        return !isSpent() && (hashIndex.getHeight() > 0 || wallet.allInputsFromWallet(hashIndex.getHash()));
+        return !isSpent() && (hashIndex.getHeight() > 0 || getWallet().allInputsFromWallet(hashIndex.getHash()));
     }
 
     @Override
@@ -80,7 +74,7 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
         if (this == o) return true;
         if (!(o instanceof HashIndexEntry)) return false;
         HashIndexEntry that = (HashIndexEntry) o;
-        return wallet.equals(that.wallet) &&
+        return getWallet().equals(that.getWallet()) &&
                 hashIndex.equals(that.hashIndex) &&
                 type == that.type &&
                 keyPurpose == that.keyPurpose;
@@ -88,7 +82,7 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
 
     @Override
     public int hashCode() {
-        return Objects.hash(wallet, hashIndex, type, keyPurpose);
+        return Objects.hash(getWallet(), hashIndex, type, keyPurpose);
     }
 
     @Override
@@ -101,6 +95,6 @@ public class HashIndexEntry extends Entry implements Comparable<HashIndexEntry>
             return o.getHashIndex().getComparisonHeight() - getHashIndex().getComparisonHeight();
         }
 
-        return (int)o.getHashIndex().getIndex() - (int)getHashIndex().getIndex();
+        return Long.compare(o.getHashIndex().getIndex(), (int)getHashIndex().getIndex());
     }
 }

src/main/java/com/sparrowwallet/sparrow/wallet/KeystoreController.java

@@ -362,11 +362,9 @@ public class KeystoreController extends WalletFormController implements Initiali
             QRScanDialog.Result result = optionalResult.get();
             if(result.extendedKey != null && result.extendedKey.getKey().isPubKeyOnly()) {
                 xpub.setText(result.extendedKey.getExtendedKey());
-            } else if(result.error != null) {
-                AppController.showErrorDialog("Invalid QR Code", result.error);
             } else if(result.exception != null) {
-                log.error("Error opening webcam", result.exception);
-                AppController.showErrorDialog("Error opening webcam", result.exception.getMessage());
+                log.error("Error scanning QR", result.exception);
+                AppController.showErrorDialog("Error scanning QR", result.exception.getMessage());
             } else {
                 AppController.showErrorDialog("Invalid QR Code", "QR Code did not contain a valid " + Network.get().getXpubHeader().getDisplayName());
             }

src/main/java/com/sparrowwallet/sparrow/wallet/NodeEntry.java

@@ -10,16 +10,14 @@ import com.sparrowwallet.sparrow.event.WalletEntryLabelChangedEvent;
 import java.util.stream.Collectors;
 
 public class NodeEntry extends Entry implements Comparable<NodeEntry> {
-    private final Wallet wallet;
     private final WalletNode node;
 
     public NodeEntry(Wallet wallet, WalletNode node) {
-        super(node.getLabel(),
+        super(wallet, node.getLabel(),
                 !node.getChildren().isEmpty() ?
                         node.getChildren().stream().map(childNode -> new NodeEntry(wallet, childNode)).collect(Collectors.toList()) :
                         node.getTransactionOutputs().stream().map(txo -> new HashIndexEntry(wallet, txo, HashIndexEntry.Type.OUTPUT, node.getKeyPurpose())).collect(Collectors.toList()));
 
-        this.wallet = wallet;
         this.node = node;
 
         labelProperty().addListener((observable, oldValue, newValue) -> {
@@ -28,24 +26,20 @@ public class NodeEntry extends Entry implements Comparable<NodeEntry> {
         });
     }
 
-    public Wallet getWallet() {
-        return wallet;
-    }
-
     public WalletNode getNode() {
         return node;
     }
 
     public Address getAddress() {
-        return wallet.getAddress(node);
+        return getWallet().getAddress(node);
     }
 
     public Script getOutputScript() {
-        return wallet.getOutputScript(node);
+        return getWallet().getOutputScript(node);
     }
 
     public String getOutputDescriptor() {
-        return wallet.getOutputDescriptor(node);
+        return getWallet().getOutputDescriptor(node);
     }
 
     @Override

src/main/java/com/sparrowwallet/sparrow/wallet/PaymentController.java

@@ -0,0 +1,354 @@
+package com.sparrowwallet.sparrow.wallet;
+
+import com.google.common.eventbus.Subscribe;
+import com.sparrowwallet.drongo.BitcoinUnit;
+import com.sparrowwallet.drongo.address.Address;
+import com.sparrowwallet.drongo.address.InvalidAddressException;
+import com.sparrowwallet.drongo.address.P2PKHAddress;
+import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.protocol.TransactionOutput;
+import com.sparrowwallet.drongo.uri.BitcoinURI;
+import com.sparrowwallet.drongo.wallet.MaxUtxoSelector;
+import com.sparrowwallet.drongo.wallet.Payment;
+import com.sparrowwallet.drongo.wallet.UtxoSelector;
+import com.sparrowwallet.sparrow.AppController;
+import com.sparrowwallet.sparrow.CurrencyRate;
+import com.sparrowwallet.sparrow.EventManager;
+import com.sparrowwallet.sparrow.control.CoinTextFormatter;
+import com.sparrowwallet.sparrow.control.CopyableTextField;
+import com.sparrowwallet.sparrow.control.FiatLabel;
+import com.sparrowwallet.sparrow.control.QRScanDialog;
+import com.sparrowwallet.sparrow.event.BitcoinUnitChangedEvent;
+import com.sparrowwallet.sparrow.event.ExchangeRatesUpdatedEvent;
+import com.sparrowwallet.sparrow.event.FiatCurrencySelectedEvent;
+import com.sparrowwallet.sparrow.io.Config;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
+import javafx.application.Platform;
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
+import javafx.event.ActionEvent;
+import javafx.fxml.FXML;
+import javafx.fxml.Initializable;
+import javafx.scene.control.*;
+import org.controlsfx.validation.ValidationResult;
+import org.controlsfx.validation.ValidationSupport;
+import org.controlsfx.validation.Validator;
+
+import java.net.URL;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.*;
+
+public class PaymentController extends WalletFormController implements Initializable {
+    private SendController sendController;
+
+    private ValidationSupport validationSupport;
+
+    @FXML
+    private CopyableTextField address;
+
+    @FXML
+    private TextField label;
+
+    @FXML
+    private TextField amount;
+
+    @FXML
+    private ComboBox<BitcoinUnit> amountUnit;
+
+    @FXML
+    private FiatLabel fiatAmount;
+
+    @FXML
+    private Button maxButton;
+
+    @FXML
+    private Button addPaymentButton;
+
+    private final ChangeListener<String> amountListener = new ChangeListener<>() {
+        @Override
+        public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
+            if(sendController.getUtxoSelector() instanceof MaxUtxoSelector) {
+                sendController.utxoSelectorProperty().setValue(null);
+            }
+
+            Long recipientValueSats = getRecipientValueSats();
+            if(recipientValueSats != null) {
+                setFiatAmount(AppController.getFiatCurrencyExchangeRate(), recipientValueSats);
+            } else {
+                fiatAmount.setText("");
+            }
+
+            sendController.updateTransaction();
+        }
+    };
+
+    @Override
+    public void initialize(URL location, ResourceBundle resources) {
+        EventManager.get().register(this);
+    }
+
+    public void setSendController(SendController sendController) {
+        this.sendController = sendController;
+        this.validationSupport = sendController.getValidationSupport();
+    }
+
+    @Override
+    public void initializeView() {
+        address.textProperty().addListener((observable, oldValue, newValue) -> {
+            try {
+                BitcoinURI bitcoinURI = new BitcoinURI(newValue);
+                Platform.runLater(() -> updateFromURI(bitcoinURI));
+                return;
+            } catch(Exception e) {
+                //ignore, not a URI
+            }
+
+            revalidate(amount, amountListener);
+            maxButton.setDisable(!isValidRecipientAddress());
+            sendController.updateTransaction();
+
+            if(validationSupport != null) {
+                validationSupport.setErrorDecorationEnabled(true);
+            }
+        });
+
+        label.textProperty().addListener((observable, oldValue, newValue) -> {
+            sendController.getCreateButton().setDisable(sendController.getWalletTransaction() == null || newValue == null || newValue.isEmpty() || sendController.isInsufficientFeeRate());
+            sendController.updateTransaction();
+        });
+
+        amount.setTextFormatter(new CoinTextFormatter());
+        amount.textProperty().addListener(amountListener);
+
+        amountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(sendController.getBitcoinUnit(Config.get().getBitcoinUnit())) ? 0 : 1);
+        amountUnit.valueProperty().addListener((observable, oldValue, newValue) -> {
+            Long value = getRecipientValueSats(oldValue);
+            if(value != null) {
+                DecimalFormat df = new DecimalFormat("#.#", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
+                df.setMaximumFractionDigits(8);
+                amount.setText(df.format(newValue.getValue(value)));
+            }
+        });
+
+        maxButton.setDisable(!isValidRecipientAddress());
+        sendController.utxoLabelSelectionProperty().addListener((observable, oldValue, newValue) -> {
+            maxButton.setText("Max" + newValue);
+        });
+
+        Optional<Tab> firstTab = sendController.getPaymentTabs().getTabs().stream().findFirst();
+        if(firstTab.isPresent()) {
+            PaymentController controller = (PaymentController)firstTab.get().getUserData();
+            String firstLabel = controller.label.getText();
+            label.setText(firstLabel);
+        }
+
+        addValidation(validationSupport);
+    }
+
+    private void addValidation(ValidationSupport validationSupport) {
+        this.validationSupport = validationSupport;
+
+        validationSupport.registerValidator(address, Validator.combine(
+                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Invalid Address", !newValue.isEmpty() && !isValidRecipientAddress())
+        ));
+        validationSupport.registerValidator(label, Validator.combine(
+                Validator.createEmptyValidator("Label is required")
+        ));
+        validationSupport.registerValidator(amount, Validator.combine(
+                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Inputs", sendController.isInsufficientInputs()),
+                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Value", getRecipientValueSats() != null && getRecipientValueSats() <= getRecipientDustThreshold())
+        ));
+    }
+
+    private boolean isValidRecipientAddress() {
+        try {
+            getRecipientAddress();
+            return true;
+        } catch (InvalidAddressException e) {
+            return false;
+        }
+    }
+
+    private Address getRecipientAddress() throws InvalidAddressException {
+        return Address.fromString(address.getText());
+    }
+
+    private Long getRecipientValueSats() {
+        return getRecipientValueSats(amountUnit.getSelectionModel().getSelectedItem());
+    }
+
+    private Long getRecipientValueSats(BitcoinUnit bitcoinUnit) {
+        if(amount.getText() != null && !amount.getText().isEmpty()) {
+            double fieldValue = Double.parseDouble(amount.getText().replaceAll(",", ""));
+            return bitcoinUnit.getSatsValue(fieldValue);
+        }
+
+        return null;
+    }
+
+    private void setRecipientValueSats(long recipientValue) {
+        amount.textProperty().removeListener(amountListener);
+        DecimalFormat df = new DecimalFormat("#.#", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
+        df.setMaximumFractionDigits(8);
+        amount.setText(df.format(amountUnit.getValue().getValue(recipientValue)));
+        amount.textProperty().addListener(amountListener);
+    }
+
+    private long getRecipientDustThreshold() {
+        Address address;
+        try {
+            address = getRecipientAddress();
+        } catch(InvalidAddressException e) {
+            address = new P2PKHAddress(new byte[20]);
+        }
+
+        TransactionOutput txOutput = new TransactionOutput(new Transaction(), 1L, address.getOutputScript());
+        return address.getScriptType().getDustThreshold(txOutput, sendController.getFeeRate());
+    }
+
+    private void setFiatAmount(CurrencyRate currencyRate, Long amount) {
+        if(amount != null && currencyRate != null && currencyRate.isAvailable()) {
+            fiatAmount.set(currencyRate, amount);
+        }
+    }
+
+    public void revalidate() {
+        revalidate(amount, amountListener);
+    }
+
+    private void revalidate(TextField field, ChangeListener<String> listener) {
+        field.textProperty().removeListener(listener);
+        String amt = field.getText();
+        field.setText(amt + "0");
+        field.setText(amt);
+        field.textProperty().addListener(listener);
+    }
+
+    public boolean isValidPayment() {
+        try {
+            getPayment();
+            return true;
+        } catch(IllegalStateException e) {
+            return false;
+        }
+    }
+
+    public Payment getPayment() {
+        return getPayment(false);
+    }
+
+    public Payment getPayment(boolean sendAll) {
+        try {
+            Address address = getRecipientAddress();
+            Long value = sendAll ? Long.valueOf(getRecipientDustThreshold() + 1) : getRecipientValueSats();
+
+            if(!label.getText().isEmpty() && value != null && value > getRecipientDustThreshold()) {
+                return new Payment(address, label.getText(), value, sendAll);
+            }
+        } catch(InvalidAddressException e) {
+            //ignore
+        }
+
+        throw new IllegalStateException("Invalid payment specified");
+    }
+
+    public void setPayment(Payment payment) {
+        if(getRecipientValueSats() == null || payment.getAmount() != getRecipientValueSats()) {
+            address.setText(payment.getAddress().toString());
+            if(payment.getLabel() != null) {
+                label.setText(payment.getLabel());
+            }
+            setRecipientValueSats(payment.getAmount());
+            setFiatAmount(AppController.getFiatCurrencyExchangeRate(), payment.getAmount());
+        }
+    }
+
+    public void clear() {
+        address.setText("");
+        label.setText("");
+
+        amount.textProperty().removeListener(amountListener);
+        amount.setText("");
+        amount.textProperty().addListener(amountListener);
+
+        fiatAmount.setText("");
+    }
+
+    public void setMaxInput(ActionEvent event) {
+        UtxoSelector utxoSelector = sendController.getUtxoSelector();
+        if(utxoSelector == null) {
+            MaxUtxoSelector maxUtxoSelector = new MaxUtxoSelector();
+            sendController.utxoSelectorProperty().set(maxUtxoSelector);
+        }
+
+        try {
+            List<Payment> payments = new ArrayList<>();
+            for(Tab tab : sendController.getPaymentTabs().getTabs()) {
+                PaymentController controller = (PaymentController)tab.getUserData();
+                if(controller != this) {
+                    payments.add(controller.getPayment());
+                } else {
+                    payments.add(getPayment(true));
+                }
+            }
+            sendController.updateTransaction(payments);
+        } catch(IllegalStateException e) {
+            //ignore, validation errors
+        }
+    }
+
+    public void scanQrAddress(ActionEvent event) {
+        QRScanDialog qrScanDialog = new QRScanDialog();
+        Optional<QRScanDialog.Result> optionalResult = qrScanDialog.showAndWait();
+        if(optionalResult.isPresent()) {
+            QRScanDialog.Result result = optionalResult.get();
+            if(result.uri != null) {
+                updateFromURI(result.uri);
+            }
+        }
+    }
+
+    private void updateFromURI(BitcoinURI bitcoinURI) {
+        if(bitcoinURI.getAddress() != null) {
+            address.setText(bitcoinURI.getAddress().toString());
+        }
+        if(bitcoinURI.getLabel() != null) {
+            label.setText(bitcoinURI.getLabel());
+        }
+        if(bitcoinURI.getAmount() != null) {
+            setRecipientValueSats(bitcoinURI.getAmount());
+        }
+        if(bitcoinURI.getPayjoinUrl() != null) {
+            AppController.addPayjoinURI(bitcoinURI);
+        }
+        sendController.updateTransaction();
+    }
+
+    public void addPayment(ActionEvent event) {
+        sendController.addPaymentTab();
+    }
+
+    public Button getAddPaymentButton() {
+        return addPaymentButton;
+    }
+
+    @Subscribe
+    public void bitcoinUnitChanged(BitcoinUnitChangedEvent event) {
+        BitcoinUnit unit = sendController.getBitcoinUnit(event.getBitcoinUnit());
+        amountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(unit) ? 0 : 1);
+    }
+
+    @Subscribe
+    public void fiatCurrencySelected(FiatCurrencySelectedEvent event) {
+        if(event.getExchangeSource() == ExchangeSource.NONE) {
+            fiatAmount.setCurrency(null);
+            fiatAmount.setBtcRate(0.0);
+        }
+    }
+
+    @Subscribe
+    public void exchangeRatesUpdated(ExchangeRatesUpdatedEvent event) {
+        setFiatAmount(event.getCurrencyRate(), getRecipientValueSats());
+    }
+}

src/main/java/com/sparrowwallet/sparrow/wallet/SendController.java

@@ -2,11 +2,8 @@ package com.sparrowwallet.sparrow.wallet;
 
 import com.google.common.eventbus.Subscribe;
 import com.sparrowwallet.drongo.BitcoinUnit;
-import com.sparrowwallet.drongo.address.Address;
 import com.sparrowwallet.drongo.address.InvalidAddressException;
-import com.sparrowwallet.drongo.address.P2PKHAddress;
 import com.sparrowwallet.drongo.protocol.Transaction;
-import com.sparrowwallet.drongo.protocol.TransactionOutput;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.wallet.*;
 import com.sparrowwallet.sparrow.AppController;
@@ -15,19 +12,21 @@ import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.*;
 import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.io.Config;
-import com.sparrowwallet.sparrow.io.ExchangeSource;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
 import com.sparrowwallet.sparrow.net.ElectrumServer;
-import javafx.beans.property.BooleanProperty;
-import javafx.beans.property.ObjectProperty;
-import javafx.beans.property.SimpleBooleanProperty;
-import javafx.beans.property.SimpleObjectProperty;
+import com.sparrowwallet.sparrow.net.MempoolRateSize;
+import javafx.application.Platform;
+import javafx.beans.property.*;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
+import javafx.collections.ListChangeListener;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
 import javafx.fxml.Initializable;
 import javafx.scene.Node;
 import javafx.scene.control.*;
+import javafx.scene.layout.StackPane;
 import javafx.util.StringConverter;
 import org.controlsfx.validation.ValidationResult;
 import org.controlsfx.validation.ValidationSupport;
@@ -35,7 +34,9 @@ import org.controlsfx.validation.Validator;
 import org.controlsfx.validation.decoration.StyleClassValidationDecoration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import tornadofx.control.Field;
 
+import java.io.IOException;
 import java.net.URL;
 import java.text.DecimalFormat;
 import java.text.DecimalFormatSymbols;
@@ -47,30 +48,34 @@ public class SendController extends WalletFormController implements Initializabl
     private static final Logger log = LoggerFactory.getLogger(SendController.class);
 
     public static final List<Integer> TARGET_BLOCKS_RANGE = List.of(1, 2, 3, 4, 5, 10, 25, 50, 100, 500);
+    public static final List<Long> FEE_RATES_RANGE = List.of(1L, 2L, 4L, 8L, 16L, 32L, 64L, 128L, 256L, 512L, 1024L);
 
     public static final double FALLBACK_FEE_RATE = 20000d / 1000;
 
     @FXML
-    private CopyableTextField address;
+    private TabPane paymentTabs;
 
     @FXML
-    private TextField label;
+    private ToggleGroup feeSelectionToggleGroup;
 
     @FXML
-    private TextField amount;
+    private ToggleButton targetBlocksToggle;
 
     @FXML
-    private ComboBox<BitcoinUnit> amountUnit;
+    private ToggleButton mempoolSizeToggle;
 
     @FXML
-    private FiatLabel fiatAmount;
-
-    @FXML
-    private Button maxButton;
+    private Field targetBlocksField;
 
     @FXML
     private Slider targetBlocks;
 
+    @FXML
+    private Field feeRangeField;
+
+    @FXML
+    private Slider feeRange;
+
     @FXML
     private CopyableLabel feeRate;
 
@@ -84,7 +89,10 @@ public class SendController extends WalletFormController implements Initializabl
     private FiatLabel fiatFeeAmount;
 
     @FXML
-    private FeeRatesChart feeRatesChart;
+    private BlockTargetFeeRatesChart blockTargetFeeRatesChart;
+
+    @FXML
+    private MempoolSizeFeeRatesChart mempoolSizeFeeRatesChart;
 
     @FXML
     private TransactionDiagram transactionDiagram;
@@ -95,6 +103,8 @@ public class SendController extends WalletFormController implements Initializabl
     @FXML
     private Button createButton;
 
+    private StackPane tabHeader;
+
     private final BooleanProperty userFeeSet = new SimpleBooleanProperty(false);
 
     private final ObjectProperty<UtxoSelector> utxoSelectorProperty = new SimpleObjectProperty<>(null);
@@ -107,23 +117,9 @@ public class SendController extends WalletFormController implements Initializabl
 
     private final BooleanProperty insufficientInputsProperty = new SimpleBooleanProperty(false);
 
-    private final ChangeListener<String> amountListener = new ChangeListener<>() {
-        @Override
-        public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
-            if(utxoSelectorProperty.get() instanceof MaxUtxoSelector) {
-                utxoSelectorProperty.setValue(null);
-            }
+    private final StringProperty utxoLabelSelectionProperty = new SimpleStringProperty("");
 
-            Long recipientValueSats = getRecipientValueSats();
-            if(recipientValueSats != null) {
-                setFiatAmount(AppController.getFiatCurrencyExchangeRate(), recipientValueSats);
-            } else {
-                fiatAmount.setText("");
-            }
-
-            updateTransaction();
-        }
-    };
+    private final BooleanProperty includeMempoolInputsProperty = new SimpleBooleanProperty(false);
 
     private final ChangeListener<String> feeListener = new ChangeListener<>() {
         @Override
@@ -148,16 +144,32 @@ public class SendController extends WalletFormController implements Initializabl
 
             if(targetBlocksFeeRates != null) {
                 setFeeRate(targetBlocksFeeRates.get(target));
-                feeRatesChart.select(target);
+                blockTargetFeeRatesChart.select(target);
             } else {
                 feeRate.setText("Unknown");
             }
 
-            Tooltip tooltip = new Tooltip("Target confirmation within " + target + " blocks");
+            Tooltip tooltip = new Tooltip("Target inclusion within " + target + " blocks");
             targetBlocks.setTooltip(tooltip);
 
             userFeeSet.set(false);
-            revalidate(amount, amountListener);
+            for(Tab tab : paymentTabs.getTabs()) {
+                PaymentController controller = (PaymentController)tab.getUserData();
+                controller.revalidate();
+            }
+            updateTransaction();
+        }
+    };
+
+    private final ChangeListener<Number> feeRangeListener = new ChangeListener<>() {
+        @Override
+        public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
+            setFeeRate(getFeeRangeRate());
+            userFeeSet.set(false);
+            for(Tab tab : paymentTabs.getTabs()) {
+                PaymentController controller = (PaymentController)tab.getUserData();
+                controller.revalidate();
+            }
             updateTransaction();
         }
     };
@@ -171,45 +183,40 @@ public class SendController extends WalletFormController implements Initializabl
 
     @Override
     public void initializeView() {
-        address.textProperty().addListener((observable, oldValue, newValue) -> {
-            revalidate(amount, amountListener);
-            maxButton.setDisable(!isValidRecipientAddress());
+        addValidation();
+
+        addPaymentTab();
+        initializeTabHeader(0);
+
+        paymentTabs.getTabs().addListener((ListChangeListener<Tab>) c -> {
+            if(tabHeader != null) {
+                tabHeader.setVisible(c.getList().size() > 1);
+            }
+
+            if(c.getList().size() > 1) {
+                if(!paymentTabs.getStyleClass().contains("multiple-tabs")) {
+                    paymentTabs.getStyleClass().add("multiple-tabs");
+                }
+                paymentTabs.getTabs().forEach(tab -> tab.setClosable(true));
+            } else {
+                paymentTabs.getStyleClass().remove("multiple-tabs");
+                Tab remainingTab = paymentTabs.getTabs().get(0);
+                remainingTab.setClosable(false);
+                remainingTab.setText("1");
+            }
+
             updateTransaction();
-
-            if(validationSupport != null) {
-                validationSupport.setErrorDecorationEnabled(true);
-            }
         });
 
-        label.textProperty().addListener((observable, oldValue, newValue) -> {
-            createButton.setDisable(walletTransactionProperty.get() == null || newValue == null || newValue.isEmpty() || isInsufficientFeeRate());
-        });
-
-        amount.setTextFormatter(new CoinTextFormatter());
-        amount.textProperty().addListener(amountListener);
-
-        BitcoinUnit unit = Config.get().getBitcoinUnit();
-        if(unit == null || unit.equals(BitcoinUnit.AUTO)) {
-            unit = getWalletForm().getWallet().getAutoUnit();
-        }
-
-        amountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(unit) ? 0 : 1);
-        amountUnit.valueProperty().addListener((observable, oldValue, newValue) -> {
-            Long value = getRecipientValueSats(oldValue);
-            if(value != null) {
-                DecimalFormat df = new DecimalFormat("#.#", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
-                df.setMaximumFractionDigits(8);
-                amount.setText(df.format(newValue.getValue(value)));
-            }
-        });
-
-        maxButton.setDisable(!isValidRecipientAddress());
-
         insufficientInputsProperty.addListener((observable, oldValue, newValue) -> {
-            revalidate(amount, amountListener);
+            for(Tab tab : paymentTabs.getTabs()) {
+                PaymentController controller = (PaymentController)tab.getUserData();
+                controller.revalidate();
+            }
             revalidate(fee, feeListener);
         });
 
+        targetBlocksField.managedProperty().bind(targetBlocksField.visibleProperty());
         targetBlocks.setMin(0);
         targetBlocks.setMax(TARGET_BLOCKS_RANGE.size() - 1);
         targetBlocks.setMajorTickUnit(1);
@@ -228,22 +235,57 @@ public class SendController extends WalletFormController implements Initializabl
         });
         targetBlocks.valueProperty().addListener(targetBlocksListener);
 
-        feeRatesChart.initialize();
+        feeRangeField.managedProperty().bind(feeRangeField.visibleProperty());
+        feeRangeField.visibleProperty().bind(targetBlocksField.visibleProperty().not());
+        feeRange.setMin(0);
+        feeRange.setMax(FEE_RATES_RANGE.size() - 1);
+        feeRange.setMajorTickUnit(1);
+        feeRange.setMinorTickCount(0);
+        feeRange.setLabelFormatter(new StringConverter<Double>() {
+            @Override
+            public String toString(Double object) {
+                return Long.toString(FEE_RATES_RANGE.get(object.intValue()));
+            }
+
+            @Override
+            public Double fromString(String string) {
+                return null;
+            }
+        });
+        feeRange.valueProperty().addListener(feeRangeListener);
+
+        blockTargetFeeRatesChart.managedProperty().bind(blockTargetFeeRatesChart.visibleProperty());
+        blockTargetFeeRatesChart.initialize();
         Map<Integer, Double> targetBlocksFeeRates = getTargetBlocksFeeRates();
         if(targetBlocksFeeRates != null) {
-            feeRatesChart.update(targetBlocksFeeRates);
+            blockTargetFeeRatesChart.update(targetBlocksFeeRates);
         } else {
             feeRate.setText("Unknown");
         }
 
-        int defaultTarget = TARGET_BLOCKS_RANGE.get((TARGET_BLOCKS_RANGE.size() / 2) - 1);
-        int index = TARGET_BLOCKS_RANGE.indexOf(defaultTarget);
-        targetBlocks.setValue(index);
-        feeRatesChart.select(defaultTarget);
+        mempoolSizeFeeRatesChart.managedProperty().bind(mempoolSizeFeeRatesChart.visibleProperty());
+        mempoolSizeFeeRatesChart.visibleProperty().bind(blockTargetFeeRatesChart.visibleProperty().not());
+        mempoolSizeFeeRatesChart.initialize();
+        Map<Date, Set<MempoolRateSize>> mempoolHistogram = getMempoolHistogram();
+        if(mempoolHistogram != null) {
+            mempoolSizeFeeRatesChart.update(mempoolHistogram);
+        }
+
+        FeeRatesSelection feeRatesSelection = Config.get().getFeeRatesSelection();
+        feeRatesSelection = (feeRatesSelection == null ? FeeRatesSelection.BLOCK_TARGET : feeRatesSelection);
+        setDefaultFeeRate();
+        updateFeeRateSelection(feeRatesSelection);
+        feeSelectionToggleGroup.selectToggle(feeRatesSelection == FeeRatesSelection.BLOCK_TARGET ? targetBlocksToggle : mempoolSizeToggle);
+        feeSelectionToggleGroup.selectedToggleProperty().addListener((observable, oldValue, newValue) -> {
+            FeeRatesSelection newFeeRatesSelection = (FeeRatesSelection)newValue.getUserData();
+            Config.get().setFeeRatesSelection(newFeeRatesSelection);
+            EventManager.get().post(new FeeRatesSelectionChangedEvent(newFeeRatesSelection));
+        });
 
         fee.setTextFormatter(new CoinTextFormatter());
         fee.textProperty().addListener(feeListener);
 
+        BitcoinUnit unit = getBitcoinUnit(Config.get().getBitcoinUnit());
         feeAmountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(unit) ? 0 : 1);
         feeAmountUnit.valueProperty().addListener((observable, oldValue, newValue) -> {
             Long value = getFeeValueSats(oldValue);
@@ -253,7 +295,7 @@ public class SendController extends WalletFormController implements Initializabl
         });
 
         userFeeSet.addListener((observable, oldValue, newValue) -> {
-            feeRatesChart.select(0);
+            blockTargetFeeRatesChart.select(0);
 
             Node thumb = getSliderThumb();
             if(thumb != null) {
@@ -265,6 +307,10 @@ public class SendController extends WalletFormController implements Initializabl
             }
         });
 
+        utxoLabelSelectionProperty.addListener((observable, oldValue, newValue) -> {
+            clearButton.setText("Clear" + newValue);
+        });
+
         utxoSelectorProperty.addListener((observable, oldValue, utxoSelector) -> {
             updateMaxClearButtons(utxoSelector, utxoFilterProperty.get());
         });
@@ -275,14 +321,12 @@ public class SendController extends WalletFormController implements Initializabl
 
         walletTransactionProperty.addListener((observable, oldValue, walletTransaction) -> {
             if(walletTransaction != null) {
-                if(getRecipientValueSats() == null || walletTransaction.getRecipientAmount() != getRecipientValueSats()) {
-                    setRecipientValueSats(walletTransaction.getRecipientAmount());
-                    setFiatAmount(AppController.getFiatCurrencyExchangeRate(), walletTransaction.getRecipientAmount());
-                }
+                setPayments(walletTransaction.getPayments());
 
                 double feeRate = walletTransaction.getFeeRate();
                 if(userFeeSet.get()) {
                     setTargetBlocks(getTargetBlocks(feeRate));
+                    setFeeRangeRate(feeRate);
                 } else {
                     setFeeValueSats(walletTransaction.getFee());
                 }
@@ -291,24 +335,39 @@ public class SendController extends WalletFormController implements Initializabl
             }
 
             transactionDiagram.update(walletTransaction);
-            createButton.setDisable(walletTransaction == null || label.getText().isEmpty() || isInsufficientFeeRate());
+            createButton.setDisable(walletTransaction == null || isInsufficientFeeRate());
         });
+    }
 
-        addValidation();
+    private void initializeTabHeader(int count) {
+        final int lookupCount = count;
+        Platform.runLater(() -> {
+            StackPane stackPane = (StackPane)paymentTabs.lookup(".tab-header-area");
+            if(stackPane != null) {
+                tabHeader = stackPane;
+                tabHeader.managedProperty().bind(tabHeader.visibleProperty());
+                tabHeader.setVisible(false);
+                paymentTabs.getStyleClass().remove("initial");
+            } else if(lookupCount < 20) {
+                initializeTabHeader(lookupCount+1);
+            }
+        });
+    }
+
+    public BitcoinUnit getBitcoinUnit(BitcoinUnit bitcoinUnit) {
+        BitcoinUnit unit = bitcoinUnit;
+        if(unit == null || unit.equals(BitcoinUnit.AUTO)) {
+            unit = getWalletForm().getWallet().getAutoUnit();
+        }
+        return unit;
+    }
+
+    public ValidationSupport getValidationSupport() {
+        return validationSupport;
     }
 
     private void addValidation() {
         validationSupport = new ValidationSupport();
-        validationSupport.registerValidator(address, Validator.combine(
-                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Invalid Address", !newValue.isEmpty() && !isValidRecipientAddress())
-        ));
-        validationSupport.registerValidator(label, Validator.combine(
-                Validator.createEmptyValidator("Label is required")
-        ));
-        validationSupport.registerValidator(amount, Validator.combine(
-                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Inputs", insufficientInputsProperty.get()),
-                (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Value", getRecipientValueSats() != null && getRecipientValueSats() <= getRecipientDustThreshold())
-        ));
         validationSupport.registerValidator(fee, Validator.combine(
                 (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Inputs", userFeeSet.get() && insufficientInputsProperty.get()),
                 (Control c, String newValue) -> ValidationResult.fromErrorIf( c, "Insufficient Fee", getFeeValueSats() != null && getFeeValueSats() == 0),
@@ -316,32 +375,95 @@ public class SendController extends WalletFormController implements Initializabl
         ));
 
         validationSupport.setValidationDecorator(new StyleClassValidationDecoration());
+        validationSupport.setErrorDecorationEnabled(false);
     }
 
-    private void updateTransaction() {
-        updateTransaction(false);
+    public Tab addPaymentTab() {
+        Tab tab = getPaymentTab();
+        paymentTabs.getTabs().add(tab);
+        paymentTabs.getSelectionModel().select(tab);
+        return tab;
     }
 
-    private void updateTransaction(boolean sendAll) {
+    public Tab getPaymentTab() {
+        OptionalInt highestTabNo = paymentTabs.getTabs().stream().mapToInt(tab -> Integer.parseInt(tab.getText())).max();
+        Tab tab = new Tab(Integer.toString(highestTabNo.isPresent() ? highestTabNo.getAsInt() + 1 : 1));
+
         try {
-            Address recipientAddress = getRecipientAddress();
-            long recipientDustThreshold = getRecipientDustThreshold();
-            Long recipientAmount = sendAll ? Long.valueOf(recipientDustThreshold + 1) : getRecipientValueSats();
-            if(recipientAmount != null && recipientAmount > recipientDustThreshold && (!userFeeSet.get() || (getFeeValueSats() != null && getFeeValueSats() > 0))) {
+            FXMLLoader paymentLoader = new FXMLLoader(AppController.class.getResource("wallet/payment.fxml"));
+            tab.setContent(paymentLoader.load());
+            PaymentController controller = paymentLoader.getController();
+            controller.setSendController(this);
+            controller.initializeView();
+            tab.setUserData(controller);
+            return tab;
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public List<Payment> getPayments() {
+        List<Payment> payments = new ArrayList<>();
+        for(Tab tab : paymentTabs.getTabs()) {
+            PaymentController controller = (PaymentController)tab.getUserData();
+            payments.add(controller.getPayment());
+        }
+
+        return payments;
+    }
+
+    public void setPayments(List<Payment> payments) {
+        while(paymentTabs.getTabs().size() < payments.size()) {
+            addPaymentTab();
+        }
+
+        while(paymentTabs.getTabs().size() > payments.size()) {
+            paymentTabs.getTabs().remove(paymentTabs.getTabs().size() - 1);
+        }
+
+        for(int i = 0; i < paymentTabs.getTabs().size(); i++) {
+            Payment payment = payments.get(i);
+            PaymentController controller = (PaymentController)paymentTabs.getTabs().get(i).getUserData();
+            controller.setPayment(payment);
+        }
+    }
+
+    public void updateTransaction() {
+        updateTransaction(null);
+    }
+
+    public void updateTransaction(boolean sendAll) {
+        try {
+            if(paymentTabs.getTabs().size() == 1) {
+                PaymentController controller = (PaymentController)paymentTabs.getTabs().get(0).getUserData();
+                updateTransaction(List.of(controller.getPayment(sendAll)));
+            } else {
+                updateTransaction(null);
+            }
+        } catch(IllegalStateException e) {
+            //ignore
+        }
+    }
+
+    public void updateTransaction(List<Payment> transactionPayments) {
+        try {
+            List<Payment> payments = transactionPayments != null ? transactionPayments : getPayments();
+            if(!userFeeSet.get() || (getFeeValueSats() != null && getFeeValueSats() > 0)) {
                 Wallet wallet = getWalletForm().getWallet();
                 Long userFee = userFeeSet.get() ? getFeeValueSats() : null;
                 Integer currentBlockHeight = AppController.getCurrentBlockHeight();
                 boolean groupByAddress = Config.get().isGroupByAddress();
                 boolean includeMempoolChange = Config.get().isIncludeMempoolChange();
-                WalletTransaction walletTransaction = wallet.createWalletTransaction(getUtxoSelectors(), getUtxoFilters(), recipientAddress, recipientAmount, getFeeRate(), getMinimumFeeRate(), userFee, currentBlockHeight, sendAll, groupByAddress, includeMempoolChange);
+                boolean includeMempoolInputs = includeMempoolInputsProperty.get();
+                WalletTransaction walletTransaction = wallet.createWalletTransaction(getUtxoSelectors(), getUtxoFilters(), payments, getFeeRate(), getMinimumFeeRate(), userFee, currentBlockHeight, groupByAddress, includeMempoolChange, includeMempoolInputs);
                 walletTransactionProperty.setValue(walletTransaction);
                 insufficientInputsProperty.set(false);
 
                 return;
             }
-        } catch (InvalidAddressException e) {
+        } catch(InvalidAddressException | IllegalStateException e) {
             //ignore
-        } catch (InsufficientFundsException e) {
+        } catch(InsufficientFundsException e) {
             insufficientInputsProperty.set(true);
         }
 
@@ -354,7 +476,7 @@ public class SendController extends WalletFormController implements Initializabl
         }
 
         Wallet wallet = getWalletForm().getWallet();
-        long noInputsFee = wallet.getNoInputsFee(getRecipientAddress(), getFeeRate());
+        long noInputsFee = wallet.getNoInputsFee(getPayments(), getFeeRate());
         long costOfChange = wallet.getCostOfChange(getFeeRate(), getMinimumFeeRate());
 
         return List.of(new BnBUtxoSelector(noInputsFee, costOfChange), new KnapsackUtxoSelector(noInputsFee));
@@ -369,38 +491,26 @@ public class SendController extends WalletFormController implements Initializabl
         return Collections.emptyList();
     }
 
-    private boolean isValidRecipientAddress() {
-        try {
-            getRecipientAddress();
-            return true;
-        } catch (InvalidAddressException e) {
-            return false;
+    private void updateFeeRateSelection(FeeRatesSelection feeRatesSelection) {
+        boolean blockTargetSelection = (feeRatesSelection == FeeRatesSelection.BLOCK_TARGET);
+        targetBlocksField.setVisible(blockTargetSelection);
+        blockTargetFeeRatesChart.setVisible(blockTargetSelection);
+        if(blockTargetSelection) {
+            setTargetBlocks(getTargetBlocks(getFeeRangeRate()));
+        } else {
+            setFeeRangeRate(getTargetBlocksFeeRates().get(getTargetBlocks()));
         }
+        updateTransaction();
     }
 
-    private Address getRecipientAddress() throws InvalidAddressException {
-        return Address.fromString(address.getText());
-    }
-
-    private Long getRecipientValueSats() {
-        return getRecipientValueSats(amountUnit.getSelectionModel().getSelectedItem());
-    }
-
-    private Long getRecipientValueSats(BitcoinUnit bitcoinUnit) {
-        if(amount.getText() != null && !amount.getText().isEmpty()) {
-            double fieldValue = Double.parseDouble(amount.getText().replaceAll(",", ""));
-            return bitcoinUnit.getSatsValue(fieldValue);
-        }
-
-        return null;
-    }
-
-    private void setRecipientValueSats(long recipientValue) {
-        amount.textProperty().removeListener(amountListener);
-        DecimalFormat df = new DecimalFormat("#.#", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
-        df.setMaximumFractionDigits(8);
-        amount.setText(df.format(amountUnit.getValue().getValue(recipientValue)));
-        amount.textProperty().addListener(amountListener);
+    private void setDefaultFeeRate() {
+        int defaultTarget = TARGET_BLOCKS_RANGE.get((TARGET_BLOCKS_RANGE.size() / 2) - 1);
+        int index = TARGET_BLOCKS_RANGE.indexOf(defaultTarget);
+        Double defaultRate = getTargetBlocksFeeRates().get(defaultTarget);
+        targetBlocks.setValue(index);
+        blockTargetFeeRatesChart.select(defaultTarget);
+        setFeeRangeRate(defaultRate);
+        setFeeRate(getFeeRangeRate());
     }
 
     private Long getFeeValueSats() {
@@ -436,7 +546,7 @@ public class SendController extends WalletFormController implements Initializabl
         for(Integer targetBlocks : targetBlocksFeeRates.keySet()) {
             maxTargetBlocks = Math.max(maxTargetBlocks, targetBlocks);
             Double candidate = targetBlocksFeeRates.get(targetBlocks);
-            if(feeRate > candidate) {
+            if(Math.round(feeRate) >= Math.round(candidate)) {
                 return targetBlocks;
             }
         }
@@ -448,7 +558,9 @@ public class SendController extends WalletFormController implements Initializabl
         targetBlocks.valueProperty().removeListener(targetBlocksListener);
         int index = TARGET_BLOCKS_RANGE.indexOf(target);
         targetBlocks.setValue(index);
-        feeRatesChart.select(target);
+        blockTargetFeeRatesChart.select(target);
+        Tooltip tooltip = new Tooltip("Target inclusion within " + target + " blocks");
+        targetBlocks.setTooltip(tooltip);
         targetBlocks.valueProperty().addListener(targetBlocksListener);
     }
 
@@ -463,8 +575,22 @@ public class SendController extends WalletFormController implements Initializabl
         return retrievedFeeRates;
     }
 
-    private Double getFeeRate() {
-        return getTargetBlocksFeeRates().get(getTargetBlocks());
+    private Double getFeeRangeRate() {
+        return Math.pow(2.0, feeRange.getValue());
+    }
+
+    private void setFeeRangeRate(Double feeRate) {
+        feeRange.valueProperty().removeListener(feeRangeListener);
+        feeRange.setValue(Math.log(feeRate) / Math.log(2));
+        feeRange.valueProperty().addListener(feeRangeListener);
+    }
+
+    public Double getFeeRate() {
+        if(targetBlocksField.isVisible()) {
+            return getTargetBlocksFeeRates().get(getTargetBlocks());
+        } else {
+            return getFeeRangeRate();
+        }
     }
 
     private Double getMinimumFeeRate() {
@@ -473,7 +599,11 @@ public class SendController extends WalletFormController implements Initializabl
         return Math.max(minRate, Transaction.DUST_RELAY_TX_FEE);
     }
 
-    private boolean isInsufficientFeeRate() {
+    private Map<Date, Set<MempoolRateSize>> getMempoolHistogram() {
+        return AppController.getMempoolHistogram();
+    }
+
+    public boolean isInsufficientFeeRate() {
         return walletTransactionProperty.get() != null && walletTransactionProperty.get().getFeeRate() < AppController.getMinimumRelayFeeRate();
     }
 
@@ -485,87 +615,40 @@ public class SendController extends WalletFormController implements Initializabl
         return targetBlocks.lookup(".thumb");
     }
 
-    public void setMaxInput(ActionEvent event) {
-        UtxoSelector utxoSelector = utxoSelectorProperty.get();
-        if(utxoSelector == null) {
-            MaxUtxoSelector maxUtxoSelector = new MaxUtxoSelector();
-            utxoSelectorProperty.set(maxUtxoSelector);
-        }
-
-        updateTransaction(true);
-    }
-
-    private void setFiatAmount(CurrencyRate currencyRate, Long amount) {
-        if(amount != null && currencyRate != null && currencyRate.isAvailable()) {
-            fiatAmount.set(currencyRate, amount);
-        }
-    }
-
     private void setFiatFeeAmount(CurrencyRate currencyRate, Long amount) {
         if(amount != null && currencyRate != null && currencyRate.isAvailable()) {
             fiatFeeAmount.set(currencyRate, amount);
         }
     }
 
-    private long getRecipientDustThreshold() {
-        Address address;
-        try {
-            address = getRecipientAddress();
-        } catch(InvalidAddressException e) {
-            address = new P2PKHAddress(new byte[20]);
-        }
-
-        TransactionOutput txOutput = new TransactionOutput(new Transaction(), 1L, address.getOutputScript());
-        return address.getScriptType().getDustThreshold(txOutput, getFeeRate());
-    }
-
     private void updateMaxClearButtons(UtxoSelector utxoSelector, UtxoFilter utxoFilter) {
         if(utxoSelector instanceof PresetUtxoSelector) {
             PresetUtxoSelector presetUtxoSelector = (PresetUtxoSelector)utxoSelector;
             int num = presetUtxoSelector.getPresetUtxos().size();
             String selection = " (" + num + " UTXO" + (num != 1 ? "s" : "") + " selected)";
-            maxButton.setText("Max" + selection);
-            clearButton.setText("Clear" + selection);
+            utxoLabelSelectionProperty.set(selection);
         } else if(utxoFilter instanceof ExcludeUtxoFilter) {
             ExcludeUtxoFilter excludeUtxoFilter = (ExcludeUtxoFilter)utxoFilter;
             int num = excludeUtxoFilter.getExcludedUtxos().size();
             String exclusion = " (" + num + " UTXO" + (num != 1 ? "s" : "") + " excluded)";
-            maxButton.setText("Max" + exclusion);
-            clearButton.setText("Clear" + exclusion);
+            utxoLabelSelectionProperty.set(exclusion);
         } else {
-            maxButton.setText("Max");
-            clearButton.setText("Clear");
-        }
-    }
-
-    public void scanQrAddress(ActionEvent event) {
-        QRScanDialog qrScanDialog = new QRScanDialog();
-        Optional<QRScanDialog.Result> optionalResult = qrScanDialog.showAndWait();
-        if(optionalResult.isPresent()) {
-            QRScanDialog.Result result = optionalResult.get();
-            if(result.uri != null) {
-                if(result.uri.getAddress() != null) {
-                    address.setText(result.uri.getAddress().toString());
-                }
-                if(result.uri.getLabel() != null) {
-                    label.setText(result.uri.getLabel());
-                }
-                if(result.uri.getAmount() != null) {
-                    setRecipientValueSats(result.uri.getAmount());
-                }
-            }
+            utxoLabelSelectionProperty.set("");
         }
     }
 
     public void clear(ActionEvent event) {
-        address.setText("");
-        label.setText("");
-
-        amount.textProperty().removeListener(amountListener);
-        amount.setText("");
-        amount.textProperty().addListener(amountListener);
-
-        fiatAmount.setText("");
+        boolean firstTab = true;
+        for(Iterator<Tab> iterator = paymentTabs.getTabs().iterator(); iterator.hasNext(); ) {
+            PaymentController controller = (PaymentController)iterator.next().getUserData();
+            if(firstTab) {
+                controller.clear();
+                firstTab = false;
+            } else {
+                EventManager.get().unregister(controller);
+                iterator.remove();
+            }
+        }
 
         fee.textProperty().removeListener(feeListener);
         fee.setText("");
@@ -574,15 +657,56 @@ public class SendController extends WalletFormController implements Initializabl
         fiatFeeAmount.setText("");
 
         userFeeSet.set(false);
-        targetBlocks.setValue(4);
+        setDefaultFeeRate();
         utxoSelectorProperty.setValue(null);
         utxoFilterProperty.setValue(null);
+        includeMempoolInputsProperty.set(false);
         walletTransactionProperty.setValue(null);
         createdWalletTransactionProperty.set(null);
 
         validationSupport.setErrorDecorationEnabled(false);
     }
 
+    public UtxoSelector getUtxoSelector() {
+        return utxoSelectorProperty.get();
+    }
+
+    public ObjectProperty<UtxoSelector> utxoSelectorProperty() {
+        return utxoSelectorProperty;
+    }
+
+    public boolean isInsufficientInputs() {
+        return insufficientInputsProperty.get();
+    }
+
+    public BooleanProperty insufficientInputsProperty() {
+        return insufficientInputsProperty;
+    }
+
+    public WalletTransaction getWalletTransaction() {
+        return walletTransactionProperty.get();
+    }
+
+    public ObjectProperty<WalletTransaction> walletTransactionProperty() {
+        return walletTransactionProperty;
+    }
+
+    public String getUtxoLabelSelection() {
+        return utxoLabelSelectionProperty.get();
+    }
+
+    public StringProperty utxoLabelSelectionProperty() {
+        return utxoLabelSelectionProperty;
+    }
+
+    public TabPane getPaymentTabs() {
+        return paymentTabs;
+    }
+
+    public Button getCreateButton() {
+        return createButton;
+    }
+
     private void revalidate(TextField field, ChangeListener<String> listener) {
         field.textProperty().removeListener(listener);
         String amt = field.getText();
@@ -604,17 +728,17 @@ public class SendController extends WalletFormController implements Initializabl
         addWalletTransactionNodes();
         createdWalletTransactionProperty.set(walletTransactionProperty.get());
         PSBT psbt = walletTransactionProperty.get().createPSBT();
-        EventManager.get().post(new ViewPSBTEvent(label.getText(), psbt));
+        EventManager.get().post(new ViewPSBTEvent(walletTransactionProperty.get().getPayments().get(0).getLabel(), psbt));
     }
 
     private void addWalletTransactionNodes() {
         WalletTransaction walletTransaction = walletTransactionProperty.get();
         Set<WalletNode> nodes = new LinkedHashSet<>(walletTransaction.getSelectedUtxos().values());
-        nodes.add(walletTransaction.getChangeNode());
-        WalletNode consolidationNode = walletTransaction.getConsolidationSendNode();
-        if(consolidationNode != null) {
-            nodes.add(consolidationNode);
+        if(walletTransaction.getChangeNode() != null) {
+            nodes.add(walletTransaction.getChangeNode());
         }
+        List<WalletNode> consolidationNodes = walletTransaction.getConsolidationSendNodes();
+        nodes.addAll(consolidationNodes);
 
         //All wallet nodes applicable to this transaction are stored so when the subscription status for one is updated, the history for all can be fetched in one atomic update
         walletForm.addWalletTransactionNodes(nodes);
@@ -667,42 +791,57 @@ public class SendController extends WalletFormController implements Initializabl
 
     @Subscribe
     public void feeRatesUpdated(FeeRatesUpdatedEvent event) {
-        feeRatesChart.update(event.getTargetBlockFeeRates());
-        feeRatesChart.select(getTargetBlocks());
-        setFeeRate(event.getTargetBlockFeeRates().get(getTargetBlocks()));
+        blockTargetFeeRatesChart.update(event.getTargetBlockFeeRates());
+        blockTargetFeeRatesChart.select(getTargetBlocks());
+        mempoolSizeFeeRatesChart.update(getMempoolHistogram());
+        if(targetBlocksField.isVisible()) {
+            setFeeRate(event.getTargetBlockFeeRates().get(getTargetBlocks()));
+        }
+    }
+
+    @Subscribe
+    public void feeRateSelectionChanged(FeeRatesSelectionChangedEvent event) {
+        updateFeeRateSelection(event.getFeeRateSelection());
     }
 
     @Subscribe
     public void spendUtxos(SpendUtxoEvent event) {
-        if(!event.getUtxoEntries().isEmpty() && event.getUtxoEntries().get(0).getWallet().equals(getWalletForm().getWallet())) {
-            List<BlockTransactionHashIndex> utxos = event.getUtxoEntries().stream().map(HashIndexEntry::getHashIndex).collect(Collectors.toList());
+        if(!event.getUtxos().isEmpty() && event.getWallet().equals(getWalletForm().getWallet())) {
+            if(event.getPayments() != null) {
+                clear(null);
+                setPayments(event.getPayments());
+            }
+
+            if(event.getFee() != null) {
+                setFeeValueSats(event.getFee());
+                userFeeSet.set(true);
+            }
+
+            includeMempoolInputsProperty.set(event.isIncludeMempoolInputs());
+
+            List<BlockTransactionHashIndex> utxos = event.getUtxos();
             utxoSelectorProperty.set(new PresetUtxoSelector(utxos));
             utxoFilterProperty.set(null);
-            updateTransaction(true);
+            updateTransaction(event.getPayments() == null);
         }
     }
 
     @Subscribe
     public void bitcoinUnitChanged(BitcoinUnitChangedEvent event) {
-        BitcoinUnit unit = event.getBitcoinUnit();
-        if(unit == null || unit.equals(BitcoinUnit.AUTO)) {
-            unit = getWalletForm().getWallet().getAutoUnit();
-        }
-        amountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(unit) ? 0 : 1);
+        BitcoinUnit unit = getBitcoinUnit(event.getBitcoinUnit());
         feeAmountUnit.getSelectionModel().select(BitcoinUnit.BTC.equals(unit) ? 0 : 1);
     }
 
     @Subscribe
     public void fiatCurrencySelected(FiatCurrencySelectedEvent event) {
         if(event.getExchangeSource() == ExchangeSource.NONE) {
-            fiatAmount.setCurrency(null);
-            fiatAmount.setBtcRate(0.0);
+            fiatFeeAmount.setCurrency(null);
+            fiatFeeAmount.setBtcRate(0.0);
         }
     }
 
     @Subscribe
     public void exchangeRatesUpdated(ExchangeRatesUpdatedEvent event) {
-        setFiatAmount(event.getCurrencyRate(), getRecipientValueSats());
         setFiatFeeAmount(event.getCurrencyRate(), getFeeValueSats());
     }
 

src/main/java/com/sparrowwallet/sparrow/wallet/SettingsController.java

@@ -13,10 +13,7 @@ import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.drongo.wallet.WalletModel;
 import com.sparrowwallet.sparrow.AppController;
 import com.sparrowwallet.sparrow.EventManager;
-import com.sparrowwallet.sparrow.control.CopyableLabel;
-import com.sparrowwallet.sparrow.control.DescriptorArea;
-import com.sparrowwallet.sparrow.control.TextAreaDialog;
-import com.sparrowwallet.sparrow.control.WalletPasswordDialog;
+import com.sparrowwallet.sparrow.control.*;
 import com.sparrowwallet.sparrow.event.RequestOpenWalletsEvent;
 import com.sparrowwallet.sparrow.event.SettingsChangedEvent;
 import com.sparrowwallet.sparrow.event.StorageEvent;
@@ -251,6 +248,21 @@ public class SettingsController extends WalletFormController implements Initiali
         }
     }
 
+    public void scanDescriptorQR(ActionEvent event) {
+        QRScanDialog qrScanDialog = new QRScanDialog();
+        Optional<QRScanDialog.Result> optionalResult = qrScanDialog.showAndWait();
+        if(optionalResult.isPresent()) {
+            QRScanDialog.Result result = optionalResult.get();
+            if(result.outputDescriptor != null) {
+                setDescriptorText(result.outputDescriptor.toString());
+            } else if(result.payload != null && !result.payload.isEmpty()) {
+                setDescriptorText(result.payload);
+            } else if(result.exception != null) {
+                AppController.showErrorDialog("Error scanning QR", result.exception.getMessage());
+            }
+        }
+    }
+
     public void editDescriptor(ActionEvent event) {
         OutputDescriptor outputDescriptor = OutputDescriptor.getOutputDescriptor(walletForm.getWallet());
         String outputDescriptorString = outputDescriptor.toString(walletForm.getWallet().isValid());
@@ -260,22 +272,26 @@ public class SettingsController extends WalletFormController implements Initiali
         dialog.getDialogPane().setHeaderText("Wallet output descriptor:");
         Optional<String> text = dialog.showAndWait();
         if(text.isPresent() && !text.get().isEmpty() && !text.get().equals(outputDescriptorString)) {
-            try {
-                OutputDescriptor editedOutputDescriptor = OutputDescriptor.getOutputDescriptor(text.get());
-                Wallet editedWallet = editedOutputDescriptor.toWallet();
+            setDescriptorText(text.get());
+        }
+    }
 
-                editedWallet.setName(getWalletForm().getWallet().getName());
-                keystoreTabs.getTabs().removeAll(keystoreTabs.getTabs());
-                totalKeystores.unbind();
-                totalKeystores.setValue(0);
-                walletForm.setWallet(editedWallet);
-                initialising = true;
-                setFieldsFromWallet(editedWallet);
+    private void setDescriptorText(String text) {
+        try {
+            OutputDescriptor editedOutputDescriptor = OutputDescriptor.getOutputDescriptor(text.trim().replace("\\", ""));
+            Wallet editedWallet = editedOutputDescriptor.toWallet();
 
-                EventManager.get().post(new SettingsChangedEvent(editedWallet, SettingsChangedEvent.Type.POLICY));
-            } catch(Exception e) {
-                AppController.showErrorDialog("Invalid output descriptor", e.getMessage());
-            }
+            editedWallet.setName(getWalletForm().getWallet().getName());
+            keystoreTabs.getTabs().removeAll(keystoreTabs.getTabs());
+            totalKeystores.unbind();
+            totalKeystores.setValue(0);
+            walletForm.setWallet(editedWallet);
+            initialising = true;
+            setFieldsFromWallet(editedWallet);
+
+            EventManager.get().post(new SettingsChangedEvent(editedWallet, SettingsChangedEvent.Type.POLICY));
+        } catch(Exception e) {
+            AppController.showErrorDialog("Invalid output descriptor", e.getMessage());
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/wallet/TransactionEntry.java

@@ -2,10 +2,9 @@ package com.sparrowwallet.sparrow.wallet;
 
 import com.google.common.eventbus.Subscribe;
 import com.sparrowwallet.drongo.KeyPurpose;
-import com.sparrowwallet.drongo.wallet.BlockTransaction;
-import com.sparrowwallet.drongo.wallet.BlockTransactionHash;
-import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
-import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.drongo.protocol.TransactionInput;
+import com.sparrowwallet.drongo.protocol.TransactionOutput;
+import com.sparrowwallet.drongo.wallet.*;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.WalletTabData;
 import com.sparrowwallet.sparrow.event.WalletBlockHeightChangedEvent;
@@ -20,12 +19,10 @@ import java.util.*;
 import java.util.stream.Collectors;
 
 public class TransactionEntry extends Entry implements Comparable<TransactionEntry> {
-    private final Wallet wallet;
     private final BlockTransaction blockTransaction;
 
     public TransactionEntry(Wallet wallet, BlockTransaction blockTransaction, Map<BlockTransactionHashIndex, KeyPurpose> inputs, Map<BlockTransactionHashIndex, KeyPurpose> outputs) {
-        super(blockTransaction.getLabel(), createChildEntries(wallet, inputs, outputs));
-        this.wallet = wallet;
+        super(wallet, blockTransaction.getLabel(), createChildEntries(wallet, inputs, outputs));
         this.blockTransaction = blockTransaction;
 
         labelProperty().addListener((observable, oldValue, newValue) -> {
@@ -39,10 +36,6 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
         }
     }
 
-    public Wallet getWallet() {
-        return wallet;
-    }
-
     public BlockTransaction getBlockTransaction() {
         return blockTransaction;
     }
@@ -71,7 +64,7 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
     }
 
     public int calculateConfirmations() {
-        return blockTransaction.getConfirmations(wallet.getStoredBlockHeight());
+        return blockTransaction.getConfirmations(getWallet().getStoredBlockHeight());
     }
 
     public String getConfirmationsDescription() {
@@ -85,6 +78,35 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
         }
     }
 
+    public boolean isComplete() {
+        int validEntries = 0;
+        Map<BlockTransactionHashIndex, WalletNode> walletTxos = getWallet().getWalletTxos();
+        for(TransactionInput txInput : blockTransaction.getTransaction().getInputs()) {
+            Optional<BlockTransactionHashIndex> optRef = walletTxos.keySet().stream().filter(ref -> ref.getHash().equals(txInput.getOutpoint().getHash()) && ref.getIndex() == txInput.getOutpoint().getIndex()).findFirst();
+            if(optRef.isPresent()) {
+                validEntries++;
+                if(getChildren().stream().noneMatch(entry -> ((HashIndexEntry)entry).getHashIndex().equals(optRef.get().getSpentBy()) && ((HashIndexEntry)entry).getType().equals(HashIndexEntry.Type.INPUT))) {
+                    return false;
+                }
+            }
+        }
+        for(TransactionOutput txOutput : blockTransaction.getTransaction().getOutputs()) {
+            Optional<BlockTransactionHashIndex> optRef = walletTxos.keySet().stream().filter(ref -> ref.getHash().equals(txOutput.getHash()) && ref.getIndex() == txOutput.getIndex()).findFirst();
+            if(optRef.isPresent()) {
+                validEntries++;
+                if(getChildren().stream().noneMatch(entry -> ((HashIndexEntry)entry).getHashIndex().equals(optRef.get()) && ((HashIndexEntry)entry).getType().equals(HashIndexEntry.Type.OUTPUT))) {
+                    return false;
+                }
+            }
+        }
+
+        if(getChildren().size() != validEntries) {
+            return false;
+        }
+
+        return true;
+    }
+
     private static List<Entry> createChildEntries(Wallet wallet, Map<BlockTransactionHashIndex, KeyPurpose> incoming, Map<BlockTransactionHashIndex, KeyPurpose> outgoing) {
         List<Entry> incomingOutputEntries = incoming.entrySet().stream().map(input -> new TransactionHashIndexEntry(wallet, input.getKey(), HashIndexEntry.Type.OUTPUT, input.getValue())).collect(Collectors.toList());
         List<Entry> outgoingInputEntries = outgoing.entrySet().stream().map(output -> new TransactionHashIndexEntry(wallet, output.getKey(), HashIndexEntry.Type.INPUT, output.getValue())).collect(Collectors.toList());
@@ -97,15 +119,15 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
             TransactionHashIndexEntry entry1 = (TransactionHashIndexEntry) o1;
             TransactionHashIndexEntry entry2 = (TransactionHashIndexEntry) o2;
 
-            if (!entry1.getHashIndex().getHash().equals(entry2.getHashIndex().getHash())) {
+            if(!entry1.getHashIndex().getHash().equals(entry2.getHashIndex().getHash())) {
                 return entry1.getHashIndex().getHash().compareTo(entry2.getHashIndex().getHash());
             }
 
-            if (!entry1.getType().equals(entry2.getType())) {
+            if(!entry1.getType().equals(entry2.getType())) {
                 return entry1.getType().ordinal() - entry2.getType().ordinal();
             }
 
-            return (int) entry1.getHashIndex().getIndex() - (int) entry2.getHashIndex().getIndex();
+            return Long.compare(entry1.getHashIndex().getIndex(), entry2.getHashIndex().getIndex());
         });
 
         return childEntries;
@@ -116,14 +138,12 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         TransactionEntry that = (TransactionEntry) o;
-        // Even though the txid identifies a transaction, receiving an incomplete set of script hash notifications can result in some inputs/outputs for a tx being missing.
-        // To resolve this we check the number of children, but not the children themselves (since we don't care here when they are spent)
-        return wallet.equals(that.wallet) && blockTransaction.equals(that.blockTransaction) && getChildren().size() == that.getChildren().size();
+        return getWallet().equals(that.getWallet()) && blockTransaction.equals(that.blockTransaction);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(wallet, blockTransaction, getChildren().size());
+        return Objects.hash(getWallet(), blockTransaction, getChildren().size());
     }
 
     @Override
@@ -211,7 +231,7 @@ public class TransactionEntry extends Entry implements Comparable<TransactionEnt
     @Subscribe
     public void walletTabsClosed(WalletTabsClosedEvent event) {
         for(WalletTabData tabData : event.getClosedWalletTabData()) {
-            if(tabData.getWalletForm().getWallet() == wallet) {
+            if(tabData.getWalletForm().getWallet() == getWallet()) {
                 try {
                     EventManager.get().unregister(this);
                 } catch(IllegalArgumentException e) {

src/main/java/com/sparrowwallet/sparrow/wallet/TransactionsController.java

@@ -9,7 +9,7 @@ import com.sparrowwallet.sparrow.control.CoinLabel;
 import com.sparrowwallet.sparrow.control.FiatLabel;
 import com.sparrowwallet.sparrow.control.TransactionsTreeTable;
 import com.sparrowwallet.sparrow.event.*;
-import com.sparrowwallet.sparrow.io.ExchangeSource;
+import com.sparrowwallet.sparrow.net.ExchangeSource;
 import javafx.collections.ListChangeListener;
 import javafx.fxml.FXML;
 import javafx.fxml.Initializable;

src/main/java/com/sparrowwallet/sparrow/wallet/UtxosController.java

@@ -3,6 +3,7 @@ package com.sparrowwallet.sparrow.wallet;
 import com.google.common.eventbus.Subscribe;
 import com.sparrowwallet.drongo.BitcoinUnit;
 import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.CoinLabel;
 import com.sparrowwallet.sparrow.control.UtxosChart;
@@ -81,8 +82,9 @@ public class UtxosController extends WalletFormController implements Initializab
                 .filter(e -> e.getType().equals(HashIndexEntry.Type.OUTPUT) && e.isSpendable())
                 .collect(Collectors.toList());
 
-        EventManager.get().post(new SendActionEvent(utxoEntries));
-        Platform.runLater(() -> EventManager.get().post(new SpendUtxoEvent(utxoEntries)));
+        final List<BlockTransactionHashIndex> spendingUtxos = utxoEntries.stream().map(HashIndexEntry::getHashIndex).collect(Collectors.toList());
+        EventManager.get().post(new SendActionEvent(getWalletForm().getWallet(), spendingUtxos));
+        Platform.runLater(() -> EventManager.get().post(new SpendUtxoEvent(getWalletForm().getWallet(), spendingUtxos)));
     }
 
     public void clear(ActionEvent event) {

src/main/java/com/sparrowwallet/sparrow/wallet/WalletController.java

@@ -121,7 +121,7 @@ public class WalletController extends WalletFormController implements Initializa
 
     @Subscribe
     public void sendAction(SendActionEvent event) {
-        if(!event.getUtxoEntries().isEmpty() && event.getUtxoEntries().get(0).getWallet().equals(walletForm.getWallet())) {
+        if(!event.getUtxos().isEmpty() && event.getWallet().equals(walletForm.getWallet())) {
             selectFunction(Function.SEND);
         }
     }

src/main/java/com/sparrowwallet/sparrow/wallet/WalletForm.java

@@ -79,14 +79,14 @@ public class WalletForm {
             log.debug(node == null ? "Refreshing full wallet history" : "Requesting node wallet history for " + node.getDerivationPath());
             ElectrumServer.TransactionHistoryService historyService = new ElectrumServer.TransactionHistoryService(wallet, getWalletTransactionNodes(node));
             historyService.setOnSucceeded(workerStateEvent -> {
-                EventManager.get().post(new WalletHistoryStatusEvent(true));
+                EventManager.get().post(new WalletHistoryStatusEvent(wallet, true));
                 updateWallet(previousWallet, blockHeight);
             });
             historyService.setOnFailed(workerStateEvent -> {
                 log.error("Error retrieving wallet history", workerStateEvent.getSource().getException());
-                EventManager.get().post(new WalletHistoryStatusEvent(workerStateEvent.getSource().getException().getMessage()));
+                EventManager.get().post(new WalletHistoryStatusEvent(wallet, workerStateEvent.getSource().getException().getMessage()));
             });
-            EventManager.get().post(new WalletHistoryStatusEvent(false));
+            EventManager.get().post(new WalletHistoryStatusEvent(wallet, false));
             historyService.start();
         }
     }

src/main/java/com/sparrowwallet/sparrow/wallet/WalletTransactionsEntry.java

@@ -9,23 +9,20 @@ import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.NewWalletTransactionsEvent;
 import javafx.beans.property.LongProperty;
 import javafx.beans.property.LongPropertyBase;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.*;
 import java.util.stream.Collectors;
 
 public class WalletTransactionsEntry extends Entry {
-    private final Wallet wallet;
+    private static final Logger log = LoggerFactory.getLogger(WalletTransactionsEntry.class);
 
     public WalletTransactionsEntry(Wallet wallet) {
-        super(wallet.getName(), getWalletTransactions(wallet).stream().map(WalletTransaction::getTransactionEntry).collect(Collectors.toList()));
-        this.wallet = wallet;
+        super(wallet, wallet.getName(), getWalletTransactions(wallet).stream().map(WalletTransaction::getTransactionEntry).collect(Collectors.toList()));
         calculateBalances();
     }
 
-    public Wallet getWallet() {
-        return wallet;
-    }
-
     @Override
     public Long getValue() {
         return getBalance();
@@ -54,7 +51,7 @@ public class WalletTransactionsEntry extends Entry {
     }
 
     public void updateTransactions() {
-        List<Entry> current = getWalletTransactions(wallet).stream().map(WalletTransaction::getTransactionEntry).collect(Collectors.toList());
+        List<Entry> current = getWalletTransactions(getWallet()).stream().map(WalletTransaction::getTransactionEntry).collect(Collectors.toList());
         List<Entry> previous = new ArrayList<>(getChildren());
 
         List<Entry> entriesAdded = new ArrayList<>(current);
@@ -67,11 +64,21 @@ public class WalletTransactionsEntry extends Entry {
 
         calculateBalances();
 
-        if(!entriesAdded.isEmpty()) {
+        List<Entry> entriesComplete = entriesAdded.stream().filter(txEntry -> ((TransactionEntry)txEntry).isComplete()).collect(Collectors.toList());
+        if(!entriesComplete.isEmpty()) {
             List<BlockTransaction> blockTransactions = entriesAdded.stream().map(txEntry -> ((TransactionEntry)txEntry).getBlockTransaction()).collect(Collectors.toList());
             long totalBlockchainValue = entriesAdded.stream().filter(txEntry -> ((TransactionEntry)txEntry).getConfirmations() > 0).mapToLong(Entry::getValue).sum();
             long totalMempoolValue = entriesAdded.stream().filter(txEntry -> ((TransactionEntry)txEntry).getConfirmations() == 0).mapToLong(Entry::getValue).sum();
-            EventManager.get().post(new NewWalletTransactionsEvent(wallet, blockTransactions, totalBlockchainValue, totalMempoolValue));
+            EventManager.get().post(new NewWalletTransactionsEvent(getWallet(), blockTransactions, totalBlockchainValue, totalMempoolValue));
+        }
+
+        if(entriesAdded.size() > entriesComplete.size()) {
+            entriesAdded.removeAll(entriesComplete);
+            for(Entry entry : entriesAdded) {
+                TransactionEntry txEntry = (TransactionEntry)entry;
+                getChildren().remove(txEntry);
+                log.warn("Removing and not notifying incomplete entry " + ((TransactionEntry)entry).getBlockTransaction().getHashAsString() + " value " + txEntry.getValue());
+            }
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/wallet/WalletUtxosEntry.java

@@ -6,18 +6,11 @@ import java.util.*;
 import java.util.stream.Collectors;
 
 public class WalletUtxosEntry extends Entry {
-    private final Wallet wallet;
-
     public WalletUtxosEntry(Wallet wallet) {
-        super(wallet.getName(), wallet.getWalletUtxos().entrySet().stream().map(entry -> new UtxoEntry(wallet, entry.getKey(), HashIndexEntry.Type.OUTPUT, entry.getValue())).collect(Collectors.toList()));
-        this.wallet = wallet;
+        super(wallet, wallet.getName(), wallet.getWalletUtxos().entrySet().stream().map(entry -> new UtxoEntry(wallet, entry.getKey(), HashIndexEntry.Type.OUTPUT, entry.getValue())).collect(Collectors.toList()));
         calculateDuplicates();
     }
 
-    public Wallet getWallet() {
-        return wallet;
-    }
-
     @Override
     public Long getValue() {
         return 0L;
@@ -42,7 +35,7 @@ public class WalletUtxosEntry extends Entry {
     }
 
     public void updateUtxos() {
-        List<Entry> current = wallet.getWalletUtxos().entrySet().stream().map(entry -> new UtxoEntry(wallet, entry.getKey(), HashIndexEntry.Type.OUTPUT, entry.getValue())).collect(Collectors.toList());
+        List<Entry> current = getWallet().getWalletUtxos().entrySet().stream().map(entry -> new UtxoEntry(getWallet(), entry.getKey(), HashIndexEntry.Type.OUTPUT, entry.getValue())).collect(Collectors.toList());
         List<Entry> previous = new ArrayList<>(getChildren());
 
         List<Entry> entriesAdded = new ArrayList<>(current);

src/main/java/module-info.java

@@ -1,5 +1,6 @@
 open module com.sparrowwallet.sparrow {
     requires java.desktop;
+    requires java.net.http;
     requires javafx.controls;
     requires javafx.fxml;
     requires javafx.graphics;
@@ -18,9 +19,9 @@ open module com.sparrowwallet.sparrow {
     requires simple.json.rpc.core;
     requires org.jetbrains.annotations;
     requires com.fasterxml.jackson.databind;
-    requires cbor;
     requires webcam.capture;
     requires netlayer.jpms;
+    requires hummingbird;
     requires centerdevice.nsmenufx;
     requires jcommander;
     requires slf4j.api;

src/main/resources/com/sparrowwallet/sparrow/darktheme.css

@@ -4,6 +4,7 @@
     -fx-base: #373e43;
     -fx-control-inner-background: derive(-fx-base, 35%);
     -fx-control-inner-background-alt: -fx-control-inner-background ;
+    -fx-default-button: -fx-accent;
 }
 
 .label{
@@ -41,7 +42,7 @@
     -fx-base: -fx-accent ;
 }
 
-.table-view{
+.table-view, .tree-view {
     /*-fx-background-color: derive(-fx-base, 10%);*/
     -fx-selection-bar-non-focused: derive(-fx-base, 50%);
 }
@@ -97,6 +98,10 @@
     -fx-fill: #e06c75;
 }
 
+.root .invalid-checksum {
+    -fx-text-fill: #e06c75;
+}
+
 .root .etched-raised-border {
     -fx-border-color: #ffffff, #000000;
     -fx-border-style: solid, solid;
@@ -153,3 +158,9 @@
     -fx-border-color: derive(-fx-base, -2%);
     /*-fx-border-width: 1;*/
 }
+
+.root .multiple-tabs {
+    -fx-background-color: derive(-fx-background, -4%);
+    -fx-border-width: 1px 0px 1px 0px;
+    -fx-border-color: derive(-fx-background, -10%);
+}

src/main/resources/com/sparrowwallet/sparrow/general.css

@@ -27,6 +27,10 @@
     -fx-padding: 3 5;
 }
 
+.form .fieldset.header .legend {
+    -fx-padding: 0 0 15px 0;
+}
+
 .id, .fixed-width {
     -fx-font-size: 13px;
     -fx-font-family: 'Roboto Mono';

src/main/resources/com/sparrowwallet/sparrow/preferences/general.fxml

@@ -12,9 +12,10 @@
 <?import javafx.collections.FXCollections?>
 <?import javafx.geometry.Insets?>
 <?import com.sparrowwallet.drongo.BitcoinUnit?>
-<?import com.sparrowwallet.sparrow.io.ExchangeSource?>
+<?import com.sparrowwallet.sparrow.net.ExchangeSource?>
 <?import com.sparrowwallet.sparrow.control.UnlabeledToggleSwitch?>
 <?import com.sparrowwallet.sparrow.control.HelpLabel?>
+<?import com.sparrowwallet.sparrow.net.FeeRatesSource?>
 
 <GridPane hgap="10.0" vgap="10.0" stylesheets="@preferences.css, @../general.css" xmlns="http://javafx.com/javafx/10.0.2-internal" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.sparrowwallet.sparrow.preferences.GeneralPreferencesController">
     <padding>
@@ -41,6 +42,18 @@
                 </ComboBox>
                 <HelpLabel helpText="Display unit for bitcoin amounts.\nAuto displays amounts over 1 BTC in BTC, and amounts under that in satoshis."/>
             </Field>
+            <Field text="Fee rates source:">
+                <ComboBox fx:id="feeRatesSource">
+                    <items>
+                        <FXCollections fx:factory="observableArrayList">
+                            <FeeRatesSource fx:constant="ELECTRUM_SERVER" />
+                            <FeeRatesSource fx:constant="MEMPOOL_SPACE" />
+                            <FeeRatesSource fx:constant="BITCOINFEES_EARN_COM" />
+                        </FXCollections>
+                    </items>
+                </ComboBox>
+                <HelpLabel helpText="Recommended fee rates can be sourced from your connected Electrum server, or an external source."/>
+            </Field>
         </Fieldset>
         <Fieldset inputGrow="SOMETIMES" text="Fiat" styleClass="wideLabelFieldSet">
             <Field text="Currency:">

src/main/resources/com/sparrowwallet/sparrow/transaction/headers.fxml

@@ -248,6 +248,11 @@
                             <Glyph fontFamily="Font Awesome 5 Free Solid" fontSize="20" icon="ARROW_DOWN" />
                         </graphic>
                     </Button>
+                    <Button fx:id="payjoinButton" defaultButton="true" HBox.hgrow="ALWAYS" text="Get Payjoin Transaction" contentDisplay="TOP" wrapText="true" textAlignment="CENTER" onAction="#getPayjoinTransaction">
+                        <graphic>
+                            <Glyph fontFamily="Font Awesome 5 Free Solid" fontSize="20" icon="RANDOM" />
+                        </graphic>
+                    </Button>
                 </HBox>
             </VBox>
         </Fieldset>

src/main/resources/com/sparrowwallet/sparrow/transaction/input.css

@@ -24,4 +24,7 @@
 
 .locktime { -fx-fill: color-grey }
 
-
+.legend {
+    -fx-content-display: RIGHT;
+    -fx-graphic-text-gap: 5px;
+}

src/main/resources/com/sparrowwallet/sparrow/wallet/payment.fxml

@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import java.lang.*?>
+<?import java.util.*?>
+<?import javafx.scene.*?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+
+<?import tornadofx.control.Form?>
+<?import tornadofx.control.Fieldset?>
+<?import tornadofx.control.Field?>
+<?import com.sparrowwallet.sparrow.control.CopyableTextField?>
+<?import javafx.collections.FXCollections?>
+<?import com.sparrowwallet.sparrow.control.FiatLabel?>
+<?import com.sparrowwallet.drongo.BitcoinUnit?>
+<?import org.controlsfx.glyphfont.Glyph?>
+
+<?import javafx.geometry.Insets?>
+<GridPane styleClass="send-form" hgap="10.0" vgap="10.0" stylesheets="@payment.css, @send.css, @wallet.css, @../script.css, @../general.css" xmlns="http://javafx.com/javafx/10.0.2-internal" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.sparrowwallet.sparrow.wallet.PaymentController">
+    <padding>
+        <Insets top="10.0" bottom="10.0" />
+    </padding>
+    <columnConstraints>
+        <ColumnConstraints prefWidth="410" />
+        <ColumnConstraints prefWidth="200" />
+        <ColumnConstraints prefWidth="105" />
+    </columnConstraints>
+    <rowConstraints>
+        <RowConstraints />
+    </rowConstraints>
+    <Form GridPane.columnIndex="0" GridPane.rowIndex="0" GridPane.columnSpan="2">
+        <Fieldset inputGrow="ALWAYS">
+            <Field text="Pay to:">
+                <CopyableTextField fx:id="address" styleClass="address-text-field"/>
+            </Field>
+            <Field text="Label:">
+                <TextField fx:id="label" />
+            </Field>
+            <Field text="Amount:">
+                <TextField fx:id="amount" styleClass="amount-field" />
+                <ComboBox fx:id="amountUnit" styleClass="amount-unit">
+                    <items>
+                        <FXCollections fx:factory="observableArrayList">
+                            <BitcoinUnit fx:constant="BTC" />
+                            <BitcoinUnit fx:constant="SATOSHIS" />
+                        </FXCollections>
+                    </items>
+                </ComboBox>
+                <Label style="-fx-pref-width: 15" />
+                <FiatLabel fx:id="fiatAmount" />
+                <Region style="-fx-pref-width: 20" />
+                <Button fx:id="maxButton" text="Max" onAction="#setMaxInput" />
+            </Field>
+        </Fieldset>
+    </Form>
+    <Form GridPane.columnIndex="2" GridPane.rowIndex="0">
+        <Fieldset inputGrow="ALWAYS" style="-fx-padding: 2 0 0 0">
+            <HBox>
+                <Button text="" onAction="#scanQrAddress" prefHeight="30">
+                    <graphic>
+                        <Glyph fontFamily="Font Awesome 5 Free Solid" fontSize="12" icon="CAMERA" />
+                    </graphic>
+                </Button>
+                <Region HBox.hgrow="ALWAYS" />
+                <Button fx:id="addPaymentButton" text="Add" onAction="#addPayment" prefHeight="30">
+                    <graphic>
+                        <Glyph fontFamily="Font Awesome 5 Free Solid" fontSize="12" icon="PLUS" />
+                    </graphic>
+                </Button>
+                <Region HBox.hgrow="ALWAYS" />
+            </HBox>
+        </Fieldset>
+    </Form>
+</GridPane>

src/main/resources/com/sparrowwallet/sparrow/wallet/receive.fxml

@@ -33,7 +33,7 @@
                 <RowConstraints />
             </rowConstraints>
             <Form GridPane.columnIndex="0" GridPane.rowIndex="0">
-                <Fieldset inputGrow="ALWAYS" text="Receive">
+                <Fieldset inputGrow="ALWAYS" text="Receive" styleClass="header">
                     <Field text="Address:">
                         <CopyableTextField fx:id="address" styleClass="address-text-field" editable="false"/>
                     </Field>

src/main/resources/com/sparrowwallet/sparrow/wallet/send.css

@@ -1,3 +1,7 @@
+.title-form .fieldset {
+    -fx-padding: 0 0 0 0;
+}
+
 .form .fieldset:horizontal .field {
     -fx-pref-height: 40px;
 }
@@ -6,6 +10,24 @@
     -fx-pref-width: 90px;
 }
 
+#paymentTabs {
+    -fx-max-height: 154px;
+}
+
+.initial .tab-header-area {
+    visibility: hidden;
+}
+
+.multiple-tabs {
+    -fx-background-color: derive(-fx-background, 20%);
+    -fx-border-width: 1px 0px 1px 0px;
+    -fx-border-color: derive(-fx-background, -5%);
+}
+
+.multiple-tabs .send-form {
+    -fx-padding: 9px 0px 9px 0px;
+}
+
 .amount-field {
     -fx-pref-width: 140px;
     -fx-min-width: 140px;
@@ -13,11 +35,11 @@
 }
 
 .amount-unit {
-    -fx-min-width: 75px;
-    -fx-max-width: 75px;
+    -fx-min-width: 76px;
+    -fx-max-width: 76px;
 }
 
-#feeRatesChart {
+.feeRatesChart {
     -fx-max-width: 335px;
     -fx-max-height: 130px;
 }
@@ -51,7 +73,7 @@
     -fx-stroke: transparent;
 }
 
-#transactionDiagram .input-label, #transactionDiagram .recipient-label, #transactionDiagram .change-label, #transactionDiagram .fee-tooltip {
+#transactionDiagram .input-label, #transactionDiagram .recipient-label, #transactionDiagram .change-label, #transactionDiagram .fee-tooltip, #transactionDiagram .transaction-tooltip {
     -fx-font-size: 13px;
     -fx-font-family: 'Roboto Mono';
 }
@@ -67,6 +89,10 @@
     -fx-stroke-width: 1px;
 }
 
+#transactionDiagram .input-dashed-line {
+    -fx-stroke-dash-array: 5px 5px;
+}
+
 #transactionDiagram .utxo-label .button {
     -fx-padding: 0;
     -fx-pref-height: 18;
@@ -81,4 +107,4 @@
 
 #transactionDiagram .utxo-label:hover .button .label .text {
     -fx-fill: -fx-text-base-color;
-}
+}