chainparams.cpp

// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2021 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <kernel/chainparams.h>

#include <chainparamsseeds.h>
#include <consensus/amount.h>
#include <consensus/merkle.h>
#include <consensus/params.h>
#include <hash.h>
#include <logging.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <script/interpreter.h>
#include <script/script.h>
#include <uint256.h>
#include <util/chaintype.h>
#include <util/strencodings.h>

#include <algorithm>
#include <cassert>
#include <cstdint>
#include <cstring>
#include <type_traits>

static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesisOutputScript, uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
{
    CMutableTransaction txNew;
    txNew.nVersion = 1;
    txNew.vin.resize(1);
    txNew.vout.resize(1);
    txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << std::vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
    txNew.vout[0].nValue = genesisReward;
    txNew.vout[0].scriptPubKey = genesisOutputScript;

    CBlock genesis;
    genesis.nTime    = nTime;
    genesis.nBits    = nBits;
    genesis.nNonce   = nNonce;
    genesis.nVersion = nVersion;
    genesis.vtx.push_back(MakeTransactionRef(std::move(txNew)));
    genesis.hashPrevBlock.SetNull();
    genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
    return genesis;
}

/**
 * Build the genesis block. Note that the output of its generation
 * transaction cannot be spent since it did not originally exist in the
 * database.
 *
 * CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
 *   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
 *     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
 *     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
 *   vMerkleTree: 4a5e1e
 */
static CBlock CreateGenesisBlock(uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
{
    const char* pszTimestamp = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks";
    const CScript genesisOutputScript = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
    return CreateGenesisBlock(pszTimestamp, genesisOutputScript, nTime, nNonce, nBits, nVersion, genesisReward);
}

/**
 * Main network on which people trade goods and services.
 */
class CMainParams : public CChainParams {
public:
    CMainParams() {
        m_chain_type = ChainType::MAIN;
        consensus.signet_blocks = false;
        consensus.signet_challenge.clear();
        consensus.nSubsidyHalvingInterval = 210000;
        consensus.script_flag_exceptions.emplace( // BIP16 exception
            uint256S("0x00000000000002dc756eebf4f49723ed8d30cc28a5f108eb94b1ba88ac4f9c22"), SCRIPT_VERIFY_NONE);
        consensus.script_flag_exceptions.emplace( // Taproot exception
            uint256S("0x0000000000000000000f14c35b2d841e986ab5441de8c585d5ffe55ea1e395ad"), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS);
        consensus.BIP34Height = 227931;
        consensus.BIP34Hash = uint256S("0x000000000000024b89b42a942fe0d9fea3bb44ab7bd1b19115dd6a759c0808b8");
        consensus.BIP65Height = 388381; // 000000000000000004c2b624ed5d7756c508d90fd0da2c7c679febfa6c4735f0
        consensus.BIP66Height = 363725; // 00000000000000000379eaa19dce8c9b722d46ae6a57c2f1a988119488b50931
        consensus.CSVHeight = 419328; // 000000000000000004a1b34462cb8aeebd5799177f7a29cf28f2d1961716b5b5
        consensus.SegwitHeight = 481824; // 0000000000000000001c8018d9cb3b742ef25114f27563e3fc4a1902167f9893
        consensus.MinBIP9WarningHeight = 483840; // segwit activation height + miner confirmation window
        consensus.powLimit = uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.fPowAllowMinDifficultyBlocks = false;
        consensus.fPowNoRetargeting = false;
        consensus.nRuleChangeActivationThreshold = 1815; // 90% of 2016
        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Deployment of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = 1619222400; // April 24th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 709632; // Approximately November 12th, 2021

        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000044a50fe819c39ad624021859");
        consensus.defaultAssumeValid = uint256S("0x000000000000000000035c3f0d31e71a5ee24c5aaf3354689f65bd7b07dee632"); // 784000

        /**
         * The message start string is designed to be unlikely to occur in normal data.
         * The characters are rarely used upper ASCII, not valid as UTF-8, and produce
         * a large 32-bit integer with any alignment.
         */
        pchMessageStart[0] = 0xf9;
        pchMessageStart[1] = 0xbe;
        pchMessageStart[2] = 0xb4;
        pchMessageStart[3] = 0xd9;
        nDefaultPort = 8333;
        nPruneAfterHeight = 100000;
        m_assumed_blockchain_size = 540;
        m_assumed_chain_state_size = 7;

        genesis = CreateGenesisBlock(1231006505, 2083236893, 0x1d00ffff, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"));
        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));

        // Note that of those which support the service bits prefix, most only support a subset of
        // possible options.
        // This is fine at runtime as we'll fall back to using them as an addrfetch if they don't support the
        // service bits we want, but we should get them updated to support all service bits wanted by any
        // release ASAP to avoid it where possible.
        vSeeds.emplace_back("seed.bitcoin.sipa.be."); // Pieter Wuille, only supports x1, x5, x9, and xd
        vSeeds.emplace_back("dnsseed.bluematt.me."); // Matt Corallo, only supports x9
        vSeeds.emplace_back("dnsseed.bitcoin.dashjr.org."); // Luke Dashjr
        vSeeds.emplace_back("seed.bitcoinstats.com."); // Christian Decker, supports x1 - xf
        vSeeds.emplace_back("seed.bitcoin.jonasschnelli.ch."); // Jonas Schnelli, only supports x1, x5, x9, and xd
        vSeeds.emplace_back("seed.btc.petertodd.org."); // Peter Todd, only supports x1, x5, x9, and xd
        vSeeds.emplace_back("seed.bitcoin.sprovoost.nl."); // Sjors Provoost
        vSeeds.emplace_back("dnsseed.emzy.de."); // Stephan Oeste
        vSeeds.emplace_back("seed.bitcoin.wiz.biz."); // Jason Maurice

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,0);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,5);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,128);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x88, 0xB2, 0x1E};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x88, 0xAD, 0xE4};

        bech32_hrp = "bc";

        vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_main), std::end(chainparams_seed_main));

        fDefaultConsistencyChecks = false;
        m_is_test_chain = false;
        m_is_mockable_chain = false;

        checkpointData = {
            {
                { 11111, uint256S("0x0000000069e244f73d78e8fd29ba2fd2ed618bd6fa2ee92559f542fdb26e7c1d")},
                { 33333, uint256S("0x000000002dd5588a74784eaa7ab0507a18ad16a236e7b1ce69f00d7ddfb5d0a6")},
                { 74000, uint256S("0x0000000000573993a3c9e41ce34471c079dcf5f52a0e824a81e7f953b8661a20")},
                {105000, uint256S("0x00000000000291ce28027faea320c8d2b054b2e0fe44a773f3eefb151d6bdc97")},
                {134444, uint256S("0x00000000000005b12ffd4cd315cd34ffd4a594f430ac814c91184a0d42d2b0fe")},
                {168000, uint256S("0x000000000000099e61ea72015e79632f216fe6cb33d7899acb35b75c8303b763")},
                {193000, uint256S("0x000000000000059f452a5f7340de6682a977387c17010ff6e6c3bd83ca8b1317")},
                {210000, uint256S("0x000000000000048b95347e83192f69cf0366076336c639f9b7228e9ba171342e")},
                {216116, uint256S("0x00000000000001b4f4b433e81ee46494af945cf96014816a4e2370f11b23df4e")},
                {225430, uint256S("0x00000000000001c108384350f74090433e7fcf79a606b8e797f065b130575932")},
                {250000, uint256S("0x000000000000003887df1f29024b06fc2200b55f8af8f35453d7be294df2d214")},
                {279000, uint256S("0x0000000000000001ae8c72a0b0c301f67e3afca10e819efa9041e458e9bd7e40")},
                {295000, uint256S("0x00000000000000004d9b4ef50f0f9d686fd69db2e03af35a100370c64632a983")},
            }
        };

        m_assumeutxo_data = MapAssumeutxo{
         // TODO to be specified in a future patch.
        };

        chainTxData = ChainTxData{
            // Data from RPC: getchaintxstats 4096 000000000000000000035c3f0d31e71a5ee24c5aaf3354689f65bd7b07dee632
            .nTime    = 1680665245,
            .nTxCount = 820876044,
            .dTxRate  = 3.672283614033389,
        };
    }
};

/**
 * Testnet (v3): public test network which is reset from time to time.
 */
class CTestNetParams : public CChainParams {
public:
    CTestNetParams() {
        m_chain_type = ChainType::TESTNET;
        consensus.signet_blocks = false;
        consensus.signet_challenge.clear();
        consensus.nSubsidyHalvingInterval = 210000;
        consensus.script_flag_exceptions.emplace( // BIP16 exception
            uint256S("0x00000000dd30457c001f4095d208cc1296b0eed002427aa599874af7a432b105"), SCRIPT_VERIFY_NONE);
        consensus.BIP34Height = 21111;
        consensus.BIP34Hash = uint256S("0x0000000023b3a96d3484e5abb3755c413e7d41500f8e2a5c3f0dd01299cd8ef8");
        consensus.BIP65Height = 581885; // 00000000007f6655f22f98e72ed80d8b06dc761d5da09df0fa1dc4be4f861eb6
        consensus.BIP66Height = 330776; // 000000002104c8c45e99a8853285a3b592602a3ccde2b832481da85e9e4ba182
        consensus.CSVHeight = 770112; // 00000000025e930139bac5c6c31a403776da130831ab85be56578f3fa75369bb
        consensus.SegwitHeight = 834624; // 00000000002b980fcd729daaa248fd9316a5200e9b367f4ff2c42453e84201ca
        consensus.MinBIP9WarningHeight = 836640; // segwit activation height + miner confirmation window
        consensus.powLimit = uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.fPowAllowMinDifficultyBlocks = true;
        consensus.fPowNoRetargeting = false;
        consensus.nRuleChangeActivationThreshold = 1512; // 75% for testchains
        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Deployment of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = 1619222400; // April 24th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000977edb0244170858d07");
        consensus.defaultAssumeValid = uint256S("0x0000000000000021bc50a89cde4870d4a81ffe0153b3c8de77b435a2fd3f6761"); // 2429000

        pchMessageStart[0] = 0x0b;
        pchMessageStart[1] = 0x11;
        pchMessageStart[2] = 0x09;
        pchMessageStart[3] = 0x07;
        nDefaultPort = 18333;
        nPruneAfterHeight = 1000;
        m_assumed_blockchain_size = 42;
        m_assumed_chain_state_size = 3;

        genesis = CreateGenesisBlock(1296688602, 414098458, 0x1d00ffff, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"));
        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));

        vFixedSeeds.clear();
        vSeeds.clear();
        // nodes with support for servicebits filtering should be at the top
        vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch.");
        vSeeds.emplace_back("seed.tbtc.petertodd.org.");
        vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl.");
        vSeeds.emplace_back("testnet-seed.bluematt.me."); // Just a static list of stable node(s), only supports x9

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};

        bech32_hrp = "tb";

        vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_test), std::end(chainparams_seed_test));

        fDefaultConsistencyChecks = false;
        m_is_test_chain = true;
        m_is_mockable_chain = false;

        checkpointData = {
            {
                {546, uint256S("000000002a936ca763904c3c35fce2f3556c559c0214345d31b1bcebf76acb70")},
            }
        };

        m_assumeutxo_data = MapAssumeutxo{
            // TODO to be specified in a future patch.
        };

        chainTxData = ChainTxData{
            // Data from RPC: getchaintxstats 4096 0000000000000021bc50a89cde4870d4a81ffe0153b3c8de77b435a2fd3f6761
            .nTime    = 1681542696,
            .nTxCount = 65345929,
            .dTxRate  = 0.09855282814711661,
        };
    }
};

/**
 * Signet: test network with an additional consensus parameter (see BIP325).
 */
class SigNetParams : public CChainParams {
public:
    explicit SigNetParams(const SigNetOptions& options)
    {
        std::vector<uint8_t> bin;
        vSeeds.clear();

        if (!options.challenge) {
            bin = ParseHex("512103ad5e0edad18cb1f0fc0d28a3d4f1f3e445640337489abb10404f2d1e086be430210359ef5021964fe22d6f8e05b2463c9540ce96883fe3b278760f048f5189f2e6c452ae");
            vSeeds.emplace_back("seed.signet.bitcoin.sprovoost.nl.");

            // Hardcoded nodes can be removed once there are more DNS seeds
            vSeeds.emplace_back("178.128.221.177");
            vSeeds.emplace_back("v7ajjeirttkbnt32wpy3c6w3emwnfr3fkla7hpxcfokr3ysd3kqtzmqd.onion:38333");

            consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000000000001899d8142b0");
            consensus.defaultAssumeValid = uint256S("0x0000004429ef154f7e00b4f6b46bfbe2d2678ecd351d95bbfca437ab9a5b84ec"); // 138000
            m_assumed_blockchain_size = 1;
            m_assumed_chain_state_size = 0;
            chainTxData = ChainTxData{
                // Data from RPC: getchaintxstats 4096 0000004429ef154f7e00b4f6b46bfbe2d2678ecd351d95bbfca437ab9a5b84ec
                .nTime    = 1681127428,
                .nTxCount = 2226359,
                .dTxRate  = 0.006424463050600656,
            };
        } else {
            bin = *options.challenge;
            consensus.nMinimumChainWork = uint256{};
            consensus.defaultAssumeValid = uint256{};
            m_assumed_blockchain_size = 0;
            m_assumed_chain_state_size = 0;
            chainTxData = ChainTxData{
                0,
                0,
                0,
            };
            LogPrintf("Signet with challenge %s\n", HexStr(bin));
        }

        if (options.seeds) {
            vSeeds = *options.seeds;
        }

        m_chain_type = ChainType::SIGNET;
        consensus.signet_blocks = true;
        consensus.signet_challenge.assign(bin.begin(), bin.end());
        consensus.nSubsidyHalvingInterval = 210000;
        consensus.BIP34Height = 1;
        consensus.BIP34Hash = uint256{};
        consensus.BIP65Height = 1;
        consensus.BIP66Height = 1;
        consensus.CSVHeight = 1;
        consensus.SegwitHeight = 1;
        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.fPowAllowMinDifficultyBlocks = false;
        consensus.fPowNoRetargeting = false;
        consensus.nRuleChangeActivationThreshold = 1815; // 90% of 2016
        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
        consensus.MinBIP9WarningHeight = 0;
        consensus.powLimit = uint256S("00000377ae000000000000000000000000000000000000000000000000000000");
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        // Activation of Taproot (BIPs 340-342)
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        // message start is defined as the first 4 bytes of the sha256d of the block script
        HashWriter h{};
        h << consensus.signet_challenge;
        uint256 hash = h.GetHash();
        memcpy(pchMessageStart, hash.begin(), 4);

        nDefaultPort = 38333;
        nPruneAfterHeight = 1000;

        genesis = CreateGenesisBlock(1598918400, 52613770, 0x1e0377ae, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x00000008819873e925422c1ff0f99f7cc9bbb232af63a077a480a3633bee1ef6"));
        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));

        vFixedSeeds.clear();

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};

        bech32_hrp = "tb";

        fDefaultConsistencyChecks = false;
        m_is_test_chain = true;
        m_is_mockable_chain = false;
    }
};

/**
 * Regression test: intended for private networks only. Has minimal difficulty to ensure that
 * blocks can be found instantly.
 */
class CRegTestParams : public CChainParams
{
public:
    explicit CRegTestParams(const RegTestOptions& opts)
    {
        m_chain_type = ChainType::REGTEST;
        consensus.signet_blocks = false;
        consensus.signet_challenge.clear();
        consensus.nSubsidyHalvingInterval = 150;
        consensus.BIP34Height = 1; // Always active unless overridden
        consensus.BIP34Hash = uint256();
        consensus.BIP65Height = 1;  // Always active unless overridden
        consensus.BIP66Height = 1;  // Always active unless overridden
        consensus.CSVHeight = 1;    // Always active unless overridden
        consensus.SegwitHeight = 0; // Always active unless overridden
        consensus.MinBIP9WarningHeight = 0;
        consensus.powLimit = uint256S("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
        consensus.nPowTargetSpacing = 10 * 60;
        consensus.fPowAllowMinDifficultyBlocks = true;
        consensus.fPowNoRetargeting = true;
        consensus.nRuleChangeActivationThreshold = 108; // 75% for testchains
        consensus.nMinerConfirmationWindow = 144; // Faster than normal for regtest (144 instead of 2016)

        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay

        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay

        consensus.nMinimumChainWork = uint256{};
        consensus.defaultAssumeValid = uint256{};

        pchMessageStart[0] = 0xfa;
        pchMessageStart[1] = 0xbf;
        pchMessageStart[2] = 0xb5;
        pchMessageStart[3] = 0xda;
        nDefaultPort = 18444;
        nPruneAfterHeight = opts.fastprune ? 100 : 1000;
        m_assumed_blockchain_size = 0;
        m_assumed_chain_state_size = 0;

        for (const auto& [dep, height] : opts.activation_heights) {
            switch (dep) {
            case Consensus::BuriedDeployment::DEPLOYMENT_SEGWIT:
                consensus.SegwitHeight = int{height};
                break;
            case Consensus::BuriedDeployment::DEPLOYMENT_HEIGHTINCB:
                consensus.BIP34Height = int{height};
                break;
            case Consensus::BuriedDeployment::DEPLOYMENT_DERSIG:
                consensus.BIP66Height = int{height};
                break;
            case Consensus::BuriedDeployment::DEPLOYMENT_CLTV:
                consensus.BIP65Height = int{height};
                break;
            case Consensus::BuriedDeployment::DEPLOYMENT_CSV:
                consensus.CSVHeight = int{height};
                break;
            }
        }

        for (const auto& [deployment_pos, version_bits_params] : opts.version_bits_parameters) {
            consensus.vDeployments[deployment_pos].nStartTime = version_bits_params.start_time;
            consensus.vDeployments[deployment_pos].nTimeout = version_bits_params.timeout;
            consensus.vDeployments[deployment_pos].min_activation_height = version_bits_params.min_activation_height;
        }

        genesis = CreateGenesisBlock(1296688602, 2, 0x207fffff, 1, 50 * COIN);
        consensus.hashGenesisBlock = genesis.GetHash();
        assert(consensus.hashGenesisBlock == uint256S("0x0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"));
        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));

        vFixedSeeds.clear(); //!< Regtest mode doesn't have any fixed seeds.
        vSeeds.clear();
        vSeeds.emplace_back("dummySeed.invalid.");

        fDefaultConsistencyChecks = true;
        m_is_test_chain = true;
        m_is_mockable_chain = true;

        checkpointData = {
            {
                {0, uint256S("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206")},
            }
        };

        m_assumeutxo_data = MapAssumeutxo{
            {
                110,
                {AssumeutxoHash{uint256S("0x1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618")}, 110},
            },
            {
                200,
                {AssumeutxoHash{uint256S("0x51c8d11d8b5c1de51543c579736e786aa2736206d1e11e627568029ce092cf62")}, 200},
            },
        };

        chainTxData = ChainTxData{
            0,
            0,
            0
        };

        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};

        bech32_hrp = "bcrt";
    }
};

std::unique_ptr<const CChainParams> CChainParams::SigNet(const SigNetOptions& options)
{
    return std::make_unique<const SigNetParams>(options);
}

std::unique_ptr<const CChainParams> CChainParams::RegTest(const RegTestOptions& options)
{
    return std::make_unique<const CRegTestParams>(options);
}

std::unique_ptr<const CChainParams> CChainParams::Main()
{
    return std::make_unique<const CMainParams>();
}

std::unique_ptr<const CChainParams> CChainParams::TestNet()
{
    return std::make_unique<const CTestNetParams>();
}