diff --git a/src/Core/Chain/ChainProfile.cs b/src/Core/Chain/ChainProfile.cs
new file mode 100644
index 0000000..ae4f908
--- /dev/null
+++ b/src/Core/Chain/ChainProfile.cs
@@ -0,0 +1,134 @@
+namespace PalladiumWallet.Core.Chain;
+
+/// <summary>
+/// Tipo di rete supportato (selettore unico per tutto il wallet, blueprint §3).
+/// </summary>
+public enum NetKind
+{
+    Mainnet,
+    Testnet,
+    Regtest,
+}
+
+/// <summary>
+/// Tipo di script/indirizzo supportato (blueprint §4.3).
+/// </summary>
+public enum ScriptKind
+{
+    /// <summary>P2PKH legacy.</summary>
+    Legacy,
+
+    /// <summary>P2SH-P2WPKH (segwit wrapped).</summary>
+    WrappedSegwit,
+
+    /// <summary>P2WPKH (native segwit) — default consigliato.</summary>
+    NativeSegwit,
+
+    /// <summary>P2SH-P2WSH (multisig wrapped).</summary>
+    WrappedSegwitMultisig,
+
+    /// <summary>P2WSH (multisig native).</summary>
+    NativeSegwitMultisig,
+}
+
+/// <summary>
+/// Coppia di header di versione BIP32 (4 byte big-endian) per serializzare
+/// xprv/xpub e varianti SLIP-132 (y/z/Y/Z) — blueprint §3.
+/// </summary>
+public readonly record struct ExtKeyHeaders(uint Private, uint Public)
+{
+    /// <summary>Header privato come 4 byte big-endian (da anteporre al payload BIP32).</summary>
+    public byte[] PrivateBytes() => ToBytes(Private);
+
+    /// <summary>Header pubblico come 4 byte big-endian.</summary>
+    public byte[] PublicBytes() => ToBytes(Public);
+
+    internal static byte[] ToBytes(uint header) =>
+    [
+        (byte)(header >> 24),
+        (byte)(header >> 16),
+        (byte)(header >> 8),
+        (byte)header,
+    ];
+}
+
+/// <summary>
+/// Server di indicizzazione di bootstrap: host + porta TCP + porta SSL (blueprint §3/§9).
+/// </summary>
+public readonly record struct ServerEndpoint(string Host, int TcpPort, int SslPort);
+
+/// <summary>
+/// Checkpoint di catena: ancora la fiducia quando la verifica PoW è disattivata
+/// (blueprint §7.3). Target serializzato come "bits" compatti.
+/// </summary>
+public readonly record struct Checkpoint(int Height, string BlockHash, uint Bits);
+
+/// <summary>
+/// Profilo di rete/catena (blueprint §3): tutte le costanti specifiche della catena,
+/// centralizzate in un solo punto. Nessun magic number altrove nel codice.
+/// </summary>
+public sealed record ChainProfile
+{
+    public required NetKind Kind { get; init; }
+
+    /// <summary>Nome rete, usato anche come sottocartella dati.</summary>
+    public required string NetName { get; init; }
+
+    /// <summary>Simbolo dell'unità (es. PLM).</summary>
+    public required string CoinUnit { get; init; }
+
+    /// <summary>Prefisso WIF delle chiavi private.</summary>
+    public required byte WifPrefix { get; init; }
+
+    /// <summary>Byte di versione indirizzi P2PKH.</summary>
+    public required byte AddrP2pkh { get; init; }
+
+    /// <summary>Byte di versione indirizzi P2SH.</summary>
+    public required byte AddrP2sh { get; init; }
+
+    /// <summary>Human-readable part bech32/bech32m.</summary>
+    public required string SegwitHrp { get; init; }
+
+    /// <summary>HRP fatture BOLT11 (Lightning, fase successiva — §11).</summary>
+    public required string Bolt11Hrp { get; init; }
+
+    /// <summary>Hash del blocco genesi (hex, byte order da explorer).</summary>
+    public required string GenesisHash { get; init; }
+
+    /// <summary>Porta TCP del server di indicizzazione (non è la porta P2P del nodo).</summary>
+    public required int DefaultTcpPort { get; init; }
+
+    /// <summary>Porta SSL del server di indicizzazione.</summary>
+    public required int DefaultSslPort { get; init; }
+
+    /// <summary>Porta P2P del nodo — solo informativa: il wallet SPV non la usa.</summary>
+    public required int NodeP2pPort { get; init; }
+
+    /// <summary>Coin type SLIP-0044 nei derivation path (convenzione wallet).</summary>
+    public required int Bip44CoinType { get; init; }
+
+    /// <summary>Schema URI pagamenti BIP21 (senza i due punti).</summary>
+    public required string UriScheme { get; init; }
+
+    /// <summary>Block explorer di default.</summary>
+    public required string ExplorerUrl { get; init; }
+
+    /// <summary>
+    /// La catena usa LWMA (retargeting per-blocco, 2 minuti): un client SPV non può
+    /// ricalcolarla, quindi la verifica bits/target va saltata e la fiducia ancorata
+    /// ai checkpoint (§3/§7). Per la catena di riferimento è sempre true.
+    /// </summary>
+    public required bool SkipPowValidation { get; init; }
+
+    /// <summary>Tempo di blocco target in secondi (LWMA v2: 120s).</summary>
+    public required int BlockTimeSeconds { get; init; }
+
+    /// <summary>Header BIP32/SLIP-132 per ciascun tipo di script.</summary>
+    public required IReadOnlyDictionary<ScriptKind, ExtKeyHeaders> ExtKeyHeaders { get; init; }
+
+    /// <summary>Server di indicizzazione per il primo contatto (bootstrap).</summary>
+    public required IReadOnlyList<ServerEndpoint> BootstrapServers { get; init; }
+
+    /// <summary>Checkpoint hardcoded, aggiornati a ogni release (§7.3).</summary>
+    public required IReadOnlyList<Checkpoint> Checkpoints { get; init; }
+}
diff --git a/src/Core/Chain/ChainProfiles.cs b/src/Core/Chain/ChainProfiles.cs
new file mode 100644
index 0000000..825c3dc
--- /dev/null
+++ b/src/Core/Chain/ChainProfiles.cs
@@ -0,0 +1,90 @@
+namespace PalladiumWallet.Core.Chain;
+
+/// <summary>
+/// I tre profili di rete del wallet (blueprint §3). Valori mainnet verificati
+/// contro il sorgente del nodo (chainparams.cpp / pow.cpp) secondo il blueprint.
+/// </summary>
+public static class ChainProfiles
+{
+    public static ChainProfile Mainnet { get; } = new()
+    {
+        Kind = NetKind.Mainnet,
+        NetName = "mainnet",
+        CoinUnit = "PLM",
+        WifPrefix = 0x80,
+        AddrP2pkh = 55,   // indirizzi che iniziano con 'P'
+        AddrP2sh = 5,     // indirizzi che iniziano con '3'
+        SegwitHrp = "plm",
+        Bolt11Hrp = "plm",
+        // La mainnet riusa la genesi di Bitcoin (blueprint §3).
+        GenesisHash = "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f",
+        DefaultTcpPort = 50001,
+        DefaultSslPort = 50002,
+        NodeP2pPort = 2333,
+        Bip44CoinType = 746,
+        UriScheme = "palladium",
+        ExplorerUrl = "https://explorer.palladium-coin.com/",
+        SkipPowValidation = true,
+        BlockTimeSeconds = 120,
+        ExtKeyHeaders = new Dictionary<ScriptKind, ExtKeyHeaders>
+        {
+            [ScriptKind.Legacy] = new(0x0488ade4, 0x0488b21e),                // xprv / xpub
+            [ScriptKind.WrappedSegwit] = new(0x049d7878, 0x049d7cb2),         // yprv / ypub
+            [ScriptKind.WrappedSegwitMultisig] = new(0x0295b005, 0x0295b43f), // Yprv / Ypub
+            [ScriptKind.NativeSegwit] = new(0x04b2430c, 0x04b24746),          // zprv / zpub
+            [ScriptKind.NativeSegwitMultisig] = new(0x02aa7a99, 0x02aa7ed3),  // Zprv / Zpub
+        },
+        // TODO: popolare con i server reali prima della release (host:tcp:ssl).
+        BootstrapServers = [],
+        // TODO: popolare con [hash, bits] reali della catena (§7.3) prima della release.
+        Checkpoints = [],
+    };
+
+    public static ChainProfile Testnet { get; } = Mainnet with
+    {
+        Kind = NetKind.Testnet,
+        NetName = "testnet",
+        WifPrefix = 0xff,
+        AddrP2pkh = 127,
+        AddrP2sh = 115,
+        SegwitHrp = "tplm",
+        Bolt11Hrp = "tplm",
+        // TODO: verificare contro chainparams.cpp del nodo (il blueprint non la riporta;
+        // qui si assume la genesi di Bitcoin testnet3, da confermare).
+        GenesisHash = "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943",
+        NodeP2pPort = 12333,
+        Bip44CoinType = 1,
+        ExtKeyHeaders = new Dictionary<ScriptKind, ExtKeyHeaders>
+        {
+            // tprv/tpub dal blueprint; le varianti SLIP-132 testnet (u/v/U/V) sono
+            // i valori standard Electrum.
+            [ScriptKind.Legacy] = new(0x04358394, 0x043587cf),                // tprv / tpub
+            [ScriptKind.WrappedSegwit] = new(0x044a4e28, 0x044a5262),         // uprv / upub
+            [ScriptKind.WrappedSegwitMultisig] = new(0x024285b5, 0x024289ef), // Uprv / Upub
+            [ScriptKind.NativeSegwit] = new(0x045f18bc, 0x045f1cf6),          // vprv / vpub
+            [ScriptKind.NativeSegwitMultisig] = new(0x02575048, 0x02575483),  // Vprv / Vpub
+        },
+        BootstrapServers = [],
+        Checkpoints = [],
+    };
+
+    public static ChainProfile Regtest { get; } = Testnet with
+    {
+        Kind = NetKind.Regtest,
+        NetName = "regtest",
+        SegwitHrp = "rplm",
+        Bolt11Hrp = "rplm",
+        // TODO: verificare contro chainparams.cpp del nodo (assunta genesi regtest Bitcoin).
+        GenesisHash = "0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206",
+        NodeP2pPort = 28444,
+        Checkpoints = [],
+    };
+
+    public static ChainProfile For(NetKind kind) => kind switch
+    {
+        NetKind.Mainnet => Mainnet,
+        NetKind.Testnet => Testnet,
+        NetKind.Regtest => Regtest,
+        _ => throw new ArgumentOutOfRangeException(nameof(kind)),
+    };
+}
diff --git a/src/Core/Chain/PalladiumNetworks.cs b/src/Core/Chain/PalladiumNetworks.cs
new file mode 100644
index 0000000..c88eb97
--- /dev/null
+++ b/src/Core/Chain/PalladiumNetworks.cs
@@ -0,0 +1,125 @@
+using NBitcoin;
+using NBitcoin.DataEncoders;
+
+namespace PalladiumWallet.Core.Chain;
+
+/// <summary>
+/// Costruisce e registra le <see cref="Network"/> NBitcoin di Palladium a partire dai
+/// <see cref="ChainProfiles"/> (blueprint §19.3). Tutto il resto del codice ottiene la
+/// rete da qui, mai da costanti sparse.
+/// </summary>
+/// <summary>
+/// Identità della moneta per NBitcoin: raggruppa le tre reti sotto il codice PLM.
+/// I getter sono lazy, quindi nessuna ricorsione durante la costruzione.
+/// </summary>
+public sealed class PalladiumNetworkSet : INetworkSet
+{
+    public static readonly PalladiumNetworkSet Instance = new();
+
+    private PalladiumNetworkSet() { }
+
+    public string CryptoCode => "PLM";
+    public Network Mainnet => PalladiumNetworks.Mainnet;
+    public Network Testnet => PalladiumNetworks.Testnet;
+    public Network Regtest => PalladiumNetworks.Regtest;
+
+    public Network GetNetwork(ChainName chainName)
+    {
+        if (chainName == ChainName.Mainnet) return Mainnet;
+        if (chainName == ChainName.Testnet) return Testnet;
+        if (chainName == ChainName.Regtest) return Regtest;
+        throw new ArgumentOutOfRangeException(nameof(chainName));
+    }
+}
+
+public static class PalladiumNetworks
+{
+    // Blocco genesi di Bitcoin (la mainnet Palladium lo riusa, blueprint §3).
+    private const string MainGenesisHex =
+        "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a29ab5f49ffff001d1dac2b7c" +
+        Coinbase;
+
+    // Genesi testnet3/regtest di Bitcoin: stessa coinbase, cambiano time/bits/nonce.
+    // TODO: confermare contro chainparams.cpp del nodo (vedi ChainProfiles).
+    private const string TestGenesisHex =
+        "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4adae5494dffff001d1aa4ae18" +
+        Coinbase;
+
+    private const string RegtestGenesisHex =
+        "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4adae5494dffff7f2002000000" +
+        Coinbase;
+
+    private const string Coinbase =
+        "0101000000010000000000000000000000000000000000000000000000000000000000000000ffffffff4d04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73ffffffff0100f2052a01000000434104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac00000000";
+
+    private static readonly Lazy<Network> _mainnet = new(() => Build(ChainProfiles.Mainnet, MainGenesisHex, 0x504c4d4du));
+    private static readonly Lazy<Network> _testnet = new(() => Build(ChainProfiles.Testnet, TestGenesisHex, 0x504c4d54u));
+    private static readonly Lazy<Network> _regtest = new(() => Build(ChainProfiles.Regtest, RegtestGenesisHex, 0x504c4d52u));
+
+    public static Network Mainnet => _mainnet.Value;
+    public static Network Testnet => _testnet.Value;
+    public static Network Regtest => _regtest.Value;
+
+    public static Network For(NetKind kind) => kind switch
+    {
+        NetKind.Mainnet => Mainnet,
+        NetKind.Testnet => Testnet,
+        NetKind.Regtest => Regtest,
+        _ => throw new ArgumentOutOfRangeException(nameof(kind)),
+    };
+
+    private static Network Build(ChainProfile p, string genesisHex, uint magic)
+    {
+        var legacy = p.ExtKeyHeaders[ScriptKind.Legacy];
+
+        var builder = new NetworkBuilder()
+            .SetName($"plm-{p.NetName}")
+            .SetNetworkSet(PalladiumNetworkSet.Instance)
+            .SetChainName(p.Kind switch
+            {
+                NetKind.Mainnet => ChainName.Mainnet,
+                NetKind.Testnet => ChainName.Testnet,
+                _ => ChainName.Regtest,
+            })
+            // Magic P2P solo segnaposto: il wallet SPV non apre mai connessioni P2P
+            // (parla solo col server di indicizzazione, §3). Serve a NBitcoin per
+            // distinguere le reti registrate.
+            .SetMagic(magic)
+            .SetPort(p.NodeP2pPort)
+            .SetRPCPort(p.NodeP2pPort + 1)
+            .SetGenesis(genesisHex)
+            .SetBase58Bytes(Base58Type.PUBKEY_ADDRESS, [p.AddrP2pkh])
+            .SetBase58Bytes(Base58Type.SCRIPT_ADDRESS, [p.AddrP2sh])
+            .SetBase58Bytes(Base58Type.SECRET_KEY, [p.WifPrefix])
+            // NBitcoin gestisce una sola coppia di header BIP32 per rete: quella
+            // standard xprv/xpub. Le varianti SLIP-132 (y/z/Y/Z) si serializzano
+            // a mano con ChainProfile.ExtKeyHeaders quando servono.
+            .SetBase58Bytes(Base58Type.EXT_SECRET_KEY, legacy.PrivateBytes())
+            .SetBase58Bytes(Base58Type.EXT_PUBLIC_KEY, legacy.PublicBytes())
+            .SetBech32(Bech32Type.WITNESS_PUBKEY_ADDRESS, Encoders.Bech32(p.SegwitHrp))
+            .SetBech32(Bech32Type.WITNESS_SCRIPT_ADDRESS, Encoders.Bech32(p.SegwitHrp))
+            .SetBech32(Bech32Type.TAPROOT_ADDRESS, Encoders.Bech32(p.SegwitHrp))
+            .SetUriScheme(p.UriScheme)
+            .SetConsensus(new Consensus
+            {
+                // Valori usati solo dalle API NBitcoin che li richiedono: la validazione
+                // header reale è custom (Core/Spv) con skip PoW + checkpoint (§7).
+                PowLimit = new Target(new uint256("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff")),
+                PowTargetSpacing = TimeSpan.FromSeconds(p.BlockTimeSeconds),
+                PowTargetTimespan = TimeSpan.FromDays(14),
+                PowAllowMinDifficultyBlocks = p.Kind != NetKind.Mainnet,
+                PowNoRetargeting = p.Kind == NetKind.Regtest,
+                SubsidyHalvingInterval = 210000,
+                MajorityEnforceBlockUpgrade = 750,
+                MajorityRejectBlockOutdated = 950,
+                MajorityWindow = 1000,
+                MinimumChainWork = uint256.Zero,
+                CoinbaseMaturity = 100,
+                SupportSegwit = true,
+                SupportTaproot = true,
+                ConsensusFactory = new ConsensusFactory(),
+            });
+
+        return builder.BuildAndRegister();
+    }
+}