chore: add MIT license (copyright 2026 Davide Grilli)

Covers what Palladium Wallet is, the tech stack, build/test/run
commands and current implementation status.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -91,6 +91,3 @@ settings.local.json
 # Local agent/tooling metadata
 .agents/
 .codex/
-CLAUDE.md
-
-blueprint.md

CLAUDE.md

@@ -0,0 +1,70 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Role
+
+Operate as an **expert in cryptocurrencies and cryptography**: reason with the domain's rigor about UTXO consensus, HD key derivation (BIP32/39/SLIP-132), signature schemes and scripts (P2PKH/P2SH/P2WPKH, PSBT), address encoding (base58/bech32), Merkle/SPV proofs, and at-rest encryption. When a choice touches cryptographic correctness or fund safety, judge it through that lens and flag known risks and pitfalls (nonce reuse, missing validation, exposed keys/seed, wrong fee/coin-selection, unverified server responses). Explain trade-offs with technical precision; never take for granted what hasn't been verified.
+
+## How to assist
+
+On **every requested change**, before implementing, judge whether it makes sense and say so plainly: if a request is useful and consistent with the project, proceed; if it is useless, redundant, already covered elsewhere, or risks degrading the code, **say so** with a short rationale and propose the better alternative (or doing nothing). No automatic agreement — an honest opinion is worth more than blind execution.
+
+## What it is
+
+SPV desktop wallet (Sparrow-style) for the **Palladium (PLM)** cryptocurrency, a Bitcoin-derived UTXO chain. Windows/Linux only, no mobile. Lightning is excluded from the first release.
+
+[blueprint.md](blueprint.md) is a **reference for understanding** (consensus parameters verified against the node, algorithms, network protocol): consult it when it helps to understand an area, but **it is no longer binding** — it need not be followed to the letter or read before every change. The source of truth is the current code; the `§` references below point to the blueprint only as further reading.
+
+## Stack and structure
+
+.NET 8 + Avalonia UI + NBitcoin.
+
+```
+src/Core/   Chain/ Crypto/ Wallet/ Spv/ Net/ Storage/  (no UI dependency)
+src/App/    Avalonia GUI       src/Cli/   CLI           tests/   xUnit
+```
+
+**Non-negotiable dependency rule:** `App`/`Cli` depend only on `Core`; the UI goes through the wallet domain, never directly through network or cryptography. `Core` knows nothing about the UI.
+
+## Commands
+
+.NET 8 SDK lives in `~/.dotnet`: in non-interactive shells, before any `dotnet` command run
+`export PATH="$HOME/.dotnet:$PATH" DOTNET_ROOT="$HOME/.dotnet"`.
+
+- Build: `dotnet build`
+- Tests (headless, the primary verification layer): `dotnet test` — single: `dotnet test --filter "FullyQualifiedName~TestName"`
+- GUI hot reload: `dotnet watch --project src/App` (on WSL2/WSLg the window shows on the Windows desktop, no graphics dependencies to install)
+- CLI: `dotnet run --project src/Cli -- <command>` (no args → usage)
+- Windows publish: `dotnet publish src/App -r win-x64 -p:PublishSingleFile=true --self-contained`
+- Linux publish: `dotnet publish src/App -r linux-x64 --self-contained` (then AppImage via PupNet Deploy)
+
+**CLI** (`src/Cli`): `create`/`restore`/`restore-xpub`/`info`; `sync`/`send`/`servers`/`reset-certs` (`--server host:port [--ssl]`); `newseed`/`addresses`. Default wallet file `~/.palladium-wallet/<network>/wallets/default.wallet.json` (`--file` to change it).
+
+## Architecture (points that require reading multiple files)
+
+- **Layers (§2):** GUI → wallet domain → SPV/Sync → Network → Cryptography → Persistence; each layer depends only downward.
+- **Network profile (§3):** all chain constants (address prefixes, BIP32 headers, bech32 HRP, genesis, ports, coin_type 746) **centralized in `Core/Chain`** (`ChainProfiles`/`PalladiumNetworks`), selectable per network (mainnet/testnet/regtest). No scattered magic numbers.
+- **LWMA / skip PoW (§3, §7):** LWMA difficulty, 2-minute blocks; an SPV client cannot recompute it → `SkipPowValidation = true`, trust anchored to **hardcoded checkpoints** (§7.3). Custom layer: NBitcoin assumes Bitcoin's retargeting.
+- **NBitcoin vs custom (§19.2):** NBitcoin covers the custom network, BIP32/39, addresses, transactions, PSBT, signing, encoding, hashing — **do not reimplement these**. Hand-written custom code: JSON-RPC client for the indexing server (ElectrumX-like, §10); SPV sync with Merkle verification (§7.4); header/checkpoint validation; coin selection and fee policy; versioned encrypted JSON wallet file.
+- **PSBT-centric (§6.5):** every signing flow goes through PSBT (offline/air-gapped/multisig/hardware).
+- **Ports:** 50001/50002 = indexing server (what the SPV wallet talks to), **not** the node's P2P port (2333).
+
+## GUI conventions (`src/App`)
+
+- **Single ViewModel** `MainWindowViewModel` (CommunityToolkit.Mvvm: `[ObservableProperty]`, `[RelayCommand]`); `Core` is driven directly from here.
+- **In-app overlays, not OS windows:** details (address, transaction), settings, and help are full-screen `Border`s gated by an `IsXxxOpen` flag, not separate `Window`s — popups/top-levels are slow on WSLg. Pattern: bool property + Open/Close commands + backdrop handler and Esc key in `MainWindow`'s code-behind. Heavy network work runs off the UI thread (`Task.Run`) so the overlay never freezes.
+- **Localization:** `Localization/Loc.cs`, key→6 languages dictionary (it/en/es/fr/pt/de); in XAML `{Binding Loc[key]}`, in C# `Loc.Tr("key")`. On language change the `Loc` instance is replaced.
+- **App version:** single source = `<Version>` in `src/App/PalladiumWallet.App.csproj`; read at runtime (`MainWindowViewModel.AppVersion`) and shown in the title.
+
+## Implementation state (§16 steps 1–7 + GUI)
+
+`Core/Chain` network profiles; `Core/Crypto` BIP39/32/SLIP-132/`HdAccount`; `Core/Storage` JSON wallet v1 + AES-GCM (PBKDF2-SHA512) + data paths; `Core/Net` `ElectrumClient` (newline JSON-RPC over TCP/TLS, TOFU in `server-certs.json`, concurrent requests) + `ElectrumApi`; `Core/Spv` scripthash, mandatory Merkle verification on every confirmed tx, sync with gap limit; `Core/Wallet` `TransactionFactory` (RBF on, send-all, watch-only PSBT), `TransactionInspector` (tx detail from the server), `WalletLoader`. GUI: setup wizard, dashboard (history/send/receive with QR+copy/addresses/contacts), transaction detail, settings/server/help, multi-wallet.
+
+**TODO (§16 steps 8–9):** multisig, hardware wallet, coin control UI, fee ETA/mempool, RBF/CPFP UI, on-disk header chain, multi-server pool, proxy/Tor.
+
+## Working rules
+
+- **Cross-implementation tests (§16):** compare addresses, txids, and PSBTs against a reference wallet (golden vectors). A different address or txid is a blocking bug.
+- **Security (§17):** seed and private keys never in plaintext on disk/logs/network; every server response validated with Merkle + checkpoints; watch-only truly read-only.
+- *(Optional)* blueprint features may be deferred but must still be considered in the design.

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Davide Grilli
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,170 @@
+# Palladium Wallet
+
+**An SPV desktop wallet built specifically for the Palladium (PLM) cryptocurrency** and optimized for its chain.
+
+Unlike generic wallets adapted to many coins, Palladium Wallet is designed around Palladium's consensus parameters — a Bitcoin-derived UTXO chain with 2-minute blocks and LWMA difficulty — and centralizes them in a single network profile. This keeps it lightweight, predictable and faithful to the chain: no client-side difficulty recalculation (trust is anchored to hardcoded checkpoints), mandatory Merkle verification on every confirmed transaction, and a network client written specifically for Palladium's indexing server.
+
+## Features
+
+- **Lightweight SPV**: syncs against an indexing server (ElectrumX-like protocol) without downloading the full chain.
+- **Security**: seed and private keys encrypted on disk (AES-GCM, PBKDF2-SHA512), never in plaintext in logs or on the wire; every server response is validated with Merkle proofs + checkpoints.
+- **HD wallet** (BIP39/BIP32), SegWit/wrapped/legacy addresses, watch-only from xpub.
+- **PSBT-centric**: signing flows go through PSBT (offline / air-gapped / multisig).
+- **Multi-network**: mainnet, testnet, regtest.
+- **GUI** (Avalonia) and **CLI** on the same core.
+- **Multilingual**: Italian, English, Spanish, French, Portuguese, German.
+
+## Architecture
+
+```
+PalladiumWallet.sln
+├─ src/Core/   Chain/ Crypto/ Wallet/ Spv/ Net/ Storage/  (no UI dependency)
+├─ src/App/    Avalonia GUI
+├─ src/Cli/    CLI on the same Core
+└─ tests/      xUnit
+```
+
+Stack: **.NET 8 + Avalonia UI + NBitcoin**.
+
+---
+
+## Development environment
+
+You only need the **.NET 8 SDK**. The core and crypto are fully testable without the GUI or a real network.
+
+### Windows
+
+1. Install the .NET 8 SDK:
+   ```powershell
+   winget install Microsoft.DotNet.SDK.8
+   ```
+   (alternatively, the installer from <https://dotnet.microsoft.com/download/dotnet/8.0>)
+2. Clone the repository and restore dependencies:
+   ```powershell
+   git clone <repo-URL>
+   cd PalladiumWallet
+   dotnet restore
+   ```
+
+### Linux
+
+1. Install the .NET 8 SDK through your distro's package manager, or without root via the official script:
+   ```bash
+   curl -sSL https://dot.net/v1/dotnet-install.sh | bash -s -- --channel 8.0
+   export PATH="$HOME/.dotnet:$PATH" DOTNET_ROOT="$HOME/.dotnet"
+   ```
+   (add the two `export` lines to your `~/.bashrc` to make them permanent)
+2. Clone and restore:
+   ```bash
+   git clone <repo-URL>
+   cd PalladiumWallet
+   dotnet restore
+   ```
+
+> The GUI uses Avalonia, which runs natively on both platforms with no extra graphics dependencies.
+
+---
+
+## Running it
+
+**GUI** (with hot reload for development):
+```bash
+dotnet watch --project src/App
+```
+or a single run:
+```bash
+dotnet run --project src/App
+```
+
+**CLI** (same core, useful for scripts and headless environments):
+```bash
+dotnet run --project src/Cli -- <command>
+```
+Run without arguments for the full list of commands.
+
+---
+
+## Running tests
+
+Tests are the **primary verification layer** — the core logic and crypto run headless, without the GUI or a real network.
+
+Run the whole suite:
+```bash
+dotnet test
+```
+
+Run a single test (or a group) by name:
+```bash
+dotnet test --filter "FullyQualifiedName~TestName"
+```
+
+Run only the tests in one project:
+```bash
+dotnet test tests/PalladiumWallet.Tests
+```
+
+> Cross-implementation tests compare addresses, txids and PSBTs against reference golden vectors: a different address or txid is a blocking bug.
+
+---
+
+## Building
+
+**Development build:**
+```bash
+dotnet build
+```
+
+**Windows publish** (single self-contained executable):
+```bash
+dotnet publish src/App -r win-x64 -p:PublishSingleFile=true --self-contained
+```
+
+**Linux publish** (self-contained; the AppImage is then produced with [PupNet Deploy](https://github.com/kuiperzone/PupNet-Deploy)):
+```bash
+dotnet publish src/App -r linux-x64 --self-contained
+```
+
+The application **version** is set in a single place: the `<Version>` tag in [`src/App/PalladiumWallet.App.csproj`](src/App/PalladiumWallet.App.csproj). It appears in the window title and is stamped into the published binaries.
+
+---
+
+## User guide (quick)
+
+### First launch
+1. On first launch, choose **where to store data** (wallet, configuration, certificates) — the default path or a folder of your choice.
+2. Create a new wallet, restore from seed, or open an existing wallet.
+3. If you create a wallet, **write the seed phrase down on paper**: it will not be shown again. You can protect the file with a password.
+
+### Main tabs
+- **History** — list of transactions. *Double-click* a row to open the full detail (amount, fee, addresses, sizes, confirmations).
+- **Send** — recipient + amount (or "send all"), adjustable fee; for watch-only wallets a PSBT is produced to be signed offline.
+- **Receive** — next unused address, with a **QR code** and a **Copy** button.
+- **Addresses** — all derived addresses with balances; click for details (keys, derivation path).
+- **Contacts** — address book with labels.
+
+### Connection
+- The status indicator at the bottom shows the connection to the **indexing server**; tapping it opens the server settings.
+- Sync is SPV: it downloads only what concerns your wallet and verifies every confirmed transaction with a Merkle proof.
+
+### Settings and Help
+- **Settings**: language, display unit (PLM / mPLM / µPLM / sat), server.
+- **Help**: software information and version.
+
+### CLI in brief
+```bash
+# Wallet
+dotnet run --project src/Cli -- create   [--words 12|24] [--kind segwit|wrapped|legacy] [--net mainnet|testnet|regtest] [--password P]
+dotnet run --project src/Cli -- restore  "<mnemonic>" [...]
+dotnet run --project src/Cli -- info     [--net ...] [--password P]
+
+# Network
+dotnet run --project src/Cli -- sync     [--server host[:port]] [--ssl]
+dotnet run --project src/Cli -- send     --to ADDRESS (--amount X | --all) [--feerate sat/vB] [--broadcast]
+```
+The default wallet file is `~/.palladium-wallet/<network>/wallets/default.wallet.json` (override with `--file`).
+
+---
+
+## License
+
+Released under the MIT License. See the [LICENSE](LICENSE) file.

src/App/Localization/Loc.cs

@@ -51,6 +51,15 @@ public sealed class Loc
         ["menu.net.discover"]     = ["Cerca altri server (peer)",                                         "Discover servers (peers)",     "Buscar otros servidores (peers)",      "Rechercher d'autres serveurs (pairs)",     "Procurar outros servidores (peers)",        "Weitere Server suchen (Peers)"],
         ["menu.net.resetcerts"]   = ["Reset certificati SSL",                                             "Reset SSL certificates",       "Restablecer certificados SSL",         "Réinitialiser les certificats SSL",        "Redefinir certificados SSL",               "SSL-Zertifikate zurücksetzen"],
         ["menu.settings"]         = ["_Impostazioni",                                                     "_Settings",                    "_Configuración",                       "_Paramètres",                              "_Configurações",                           "_Einstellungen"],
+        ["menu.help"]             = ["_Help",                                                             "_Help",                        "_Ayuda",                               "_Aide",                                    "_Ajuda",                                   "_Hilfe"],
+        ["help.title"]            = ["Informazioni sul software",                                         "About this software",          "Información del software",             "À propos du logiciel",                     "Sobre o software",                         "Über die Software"],
+        ["help.info"]             = [
+            "Wallet SPV per la criptovaluta Palladium (PLM).",
+            "SPV wallet for the Palladium (PLM) cryptocurrency.",
+            "Monedero SPV para la criptomoneda Palladium (PLM).",
+            "Portefeuille SPV pour la cryptomonnaie Palladium (PLM).",
+            "Carteira SPV para a criptomoeda Palladium (PLM).",
+            "SPV-Wallet für die Kryptowährung Palladium (PLM)."],
         ["settings.unit.short"]   = ["Unità",                                                             "Unit",                         "Unidad",                               "Unité",                                    "Unidade",                                  "Einheit"],
 
         // Wizard

src/App/PalladiumWallet.App.csproj

@@ -2,6 +2,9 @@
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
     <TargetFramework>net8.0</TargetFramework>
+    <!-- Versione dell'applicazione: unico punto da modificare. Compare nel
+         titolo della finestra ed è incisa nei binari pubblicati. -->
+    <Version>0.9.0</Version>
     <Nullable>enable</Nullable>
     <ApplicationManifest>app.manifest</ApplicationManifest>
     <ApplicationIcon>Assets\logo.ico</ApplicationIcon>

src/App/ViewModels/MainWindowViewModel.cs

@@ -73,6 +73,15 @@ public partial class MainWindowViewModel : ViewModelBase
     private Loc _loc = Loc.Instance;
     public Loc Loc => _loc;
 
+    /// <summary>Versione dell'app (da &lt;Version&gt; nel csproj), formato Major.Minor.Patch.</summary>
+    public static string AppVersion =>
+        typeof(MainWindowViewModel).Assembly.GetName().Version is { } v
+            ? $"{v.Major}.{v.Minor}.{v.Build}"
+            : "";
+
+    /// <summary>Titolo della finestra con la versione, es. "Palladium Wallet 0.9.0".</summary>
+    public string WindowTitle => $"Palladium Wallet {AppVersion}";
+
     /// <summary>Unità corrente per il campo importo del pannello Invia.</summary>
     public string UnitLabel => _config.Unit;
 
@@ -309,6 +318,16 @@ public partial class MainWindowViewModel : ViewModelBase
     [RelayCommand]
     private void CloseSettings() => IsSettingsOpen = false;
 
+    /// <summary>Overlay informazioni sul software (menu Help).</summary>
+    [ObservableProperty]
+    private bool isHelpOpen;
+
+    [RelayCommand]
+    private void OpenHelp() => IsHelpOpen = true;
+
+    [RelayCommand]
+    private void CloseHelp() => IsHelpOpen = false;
+
     [ObservableProperty]
     private string connectionStatus = Loc.Tr("conn.none");
 

src/App/Views/MainWindow.axaml

@@ -9,7 +9,7 @@
         x:DataType="vm:MainWindowViewModel"
         Icon="/Assets/logo.ico"
         Width="900" Height="620"
-        Title="Palladium Wallet">
+        Title="{Binding WindowTitle}">
 
     <Design.DataContext>
         <vm:MainWindowViewModel/>
@@ -28,6 +28,8 @@
             </MenuItem>
             <MenuItem Header="{Binding Loc[menu.settings]}"
                       Command="{Binding OpenSettingsCommand}"/>
+            <MenuItem Header="{Binding Loc[menu.help]}"
+                      Command="{Binding OpenHelpCommand}"/>
         </Menu>
 
         <!-- ============ WIZARD DI SETUP (§15): un passo alla volta ============ -->
@@ -714,5 +716,33 @@
                 </StackPanel>
             </Border>
         </Border>
+
+        <!-- ============ OVERLAY HELP / INFORMAZIONI ============ -->
+        <!-- Stesso pattern dell'overlay impostazioni: apertura/chiusura istantanee. -->
+        <Border Grid.Row="0" Grid.RowSpan="3"
+                Background="#99000000"
+                Tapped="OnHelpOverlayBackdropTapped"
+                IsVisible="{Binding IsHelpOpen}">
+            <Border Background="{DynamicResource SystemControlBackgroundChromeMediumLowBrush}"
+                    BorderBrush="Gray" BorderThickness="1" CornerRadius="8"
+                    Width="460"
+                    HorizontalAlignment="Center" VerticalAlignment="Center">
+                <StackPanel Margin="24" Spacing="16">
+                    <TextBlock Text="{Binding Loc[help.title]}"
+                               FontSize="18" FontWeight="Bold"/>
+
+                    <StackPanel Spacing="4">
+                        <TextBlock Text="Palladium Wallet" FontSize="16" FontWeight="Bold"/>
+                        <TextBlock Text="{Binding WindowTitle}" FontSize="12" Foreground="Gray"/>
+                    </StackPanel>
+
+                    <TextBlock Text="{Binding Loc[help.info]}" TextWrapping="Wrap"/>
+
+                    <Button Content="{Binding Loc[addr.close]}"
+                            HorizontalAlignment="Right"
+                            Command="{Binding CloseHelpCommand}"/>
+                </StackPanel>
+            </Border>
+        </Border>
     </Grid>
 </Window>

src/App/Views/MainWindow.axaml.cs

@@ -128,6 +128,13 @@ public partial class MainWindow : Window
             vm.IsSettingsOpen = false;
     }
 
+    private void OnHelpOverlayBackdropTapped(object? sender, TappedEventArgs e)
+    {
+        if (!ReferenceEquals(e.Source, sender)) return;
+        if (DataContext is MainWindowViewModel vm)
+            vm.IsHelpOpen = false;
+    }
+
     protected override void OnKeyDown(KeyEventArgs e)
     {
         if (e.Key == Key.Escape && DataContext is MainWindowViewModel vm)
@@ -136,6 +143,7 @@ public partial class MainWindow : Window
             if (vm.AddressInfo is not null) { vm.AddressInfo = null; e.Handled = true; return; }
             if (vm.IsServerSettingsOpen) { vm.IsServerSettingsOpen = false; e.Handled = true; return; }
             if (vm.IsSettingsOpen) { vm.IsSettingsOpen = false; e.Handled = true; return; }
+            if (vm.IsHelpOpen) { vm.IsHelpOpen = false; e.Handled = true; return; }
         }
         base.OnKeyDown(e);
     }