chainparams.cpp raw
1 // Copyright (c) 2010 Satoshi Nakamoto
2 // Copyright (c) 2009-present The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6 #include <kernel/chainparams.h>
7
8 #include <chainparamsseeds.h>
9 #include <consensus/amount.h>
10 #include <consensus/merkle.h>
11 #include <consensus/params.h>
12 #include <crypto/hex_base.h>
13 #include <hash.h>
14 #include <kernel/messagestartchars.h>
15 #include <primitives/block.h>
16 #include <primitives/transaction.h>
17 #include <script/interpreter.h>
18 #include <script/script.h>
19 #include <script/verify_flags.h>
20 #include <uint256.h>
21 #include <util/chaintype.h>
22 #include <util/log.h>
23 #include <util/strencodings.h>
24
25 #include <algorithm>
26 #include <array>
27 #include <cassert>
28 #include <cstdint>
29 #include <cstring>
30 #include <iterator>
31 #include <map>
32 #include <span>
33 #include <utility>
34
35 using namespace util::hex_literals;
36
37 static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesisOutputScript, uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
38 {
39 CMutableTransaction txNew;
40 txNew.version = 1;
41 txNew.vin.resize(1);
42 txNew.vout.resize(1);
43 txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << std::vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
44 txNew.vout[0].nValue = genesisReward;
45 txNew.vout[0].scriptPubKey = genesisOutputScript;
46
47 CBlock genesis;
48 genesis.nTime = nTime;
49 genesis.nBits = nBits;
50 genesis.nNonce = nNonce;
51 genesis.nVersion = nVersion;
52 genesis.vtx.push_back(MakeTransactionRef(std::move(txNew)));
53 genesis.hashPrevBlock.SetNull();
54 genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
55 return genesis;
56 }
57
58 /**
59 * Build the genesis block. Note that the output of its generation
60 * transaction cannot be spent since it did not originally exist in the
61 * database.
62 *
63 * CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
64 * CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
65 * CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
66 * CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
67 * vMerkleTree: 4a5e1e
68 */
69 static CBlock CreateGenesisBlock(uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
70 {
71 const char* pszTimestamp = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks";
72 const CScript genesisOutputScript = CScript() << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f"_hex << OP_CHECKSIG;
73 return CreateGenesisBlock(pszTimestamp, genesisOutputScript, nTime, nNonce, nBits, nVersion, genesisReward);
74 }
75
76 void CChainParams::ApplyDeploymentOptions(const DeploymentOptions& opts)
77 {
78 for (const auto& [dep, height] : opts.activation_heights) {
79 switch (dep) {
80 case Consensus::BuriedDeployment::DEPLOYMENT_SEGWIT:
81 consensus.SegwitHeight = int{height};
82 break;
83 case Consensus::BuriedDeployment::DEPLOYMENT_HEIGHTINCB:
84 consensus.BIP34Height = int{height};
85 break;
86 case Consensus::BuriedDeployment::DEPLOYMENT_DERSIG:
87 consensus.BIP66Height = int{height};
88 break;
89 case Consensus::BuriedDeployment::DEPLOYMENT_CLTV:
90 consensus.BIP65Height = int{height};
91 break;
92 case Consensus::BuriedDeployment::DEPLOYMENT_CSV:
93 consensus.CSVHeight = int{height};
94 break;
95 }
96 }
97
98 for (const auto& [deployment_pos, version_bits_params] : opts.version_bits_parameters) {
99 consensus.vDeployments[deployment_pos].nStartTime = version_bits_params.start_time;
100 consensus.vDeployments[deployment_pos].nTimeout = version_bits_params.timeout;
101 consensus.vDeployments[deployment_pos].min_activation_height = version_bits_params.min_activation_height;
102 }
103 }
104
105 /**
106 * Main network on which people trade goods and services.
107 */
108 class CMainParams : public CChainParams {
109 public:
110 CMainParams(const MainNetOptions& opts) {
111 m_chain_type = ChainType::MAIN;
112 consensus.signet_blocks = false;
113 consensus.signet_challenge.clear();
114 consensus.nSubsidyHalvingInterval = 210000;
115 consensus.script_flag_exceptions.emplace( // BIP16 exception
116 uint256{"00000000000002dc756eebf4f49723ed8d30cc28a5f108eb94b1ba88ac4f9c22"}, SCRIPT_VERIFY_NONE);
117 consensus.script_flag_exceptions.emplace( // Taproot exception
118 uint256{"0000000000000000000f14c35b2d841e986ab5441de8c585d5ffe55ea1e395ad"}, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS);
119 consensus.BIP34Height = 227931;
120 consensus.BIP34Hash = uint256{"000000000000024b89b42a942fe0d9fea3bb44ab7bd1b19115dd6a759c0808b8"};
121 consensus.BIP65Height = 388381; // 000000000000000004c2b624ed5d7756c508d90fd0da2c7c679febfa6c4735f0
122 consensus.BIP66Height = 363725; // 00000000000000000379eaa19dce8c9b722d46ae6a57c2f1a988119488b50931
123 consensus.CSVHeight = 419328; // 000000000000000004a1b34462cb8aeebd5799177f7a29cf28f2d1961716b5b5
124 consensus.SegwitHeight = 481824; // 0000000000000000001c8018d9cb3b742ef25114f27563e3fc4a1902167f9893
125 consensus.MinBIP9WarningHeight = 711648; // taproot activation height + miner confirmation window
126 consensus.powLimit = uint256{"00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"};
127 consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
128 consensus.nPowTargetSpacing = 10 * 60;
129 consensus.fPowAllowMinDifficultyBlocks = false;
130 consensus.enforce_BIP94 = false;
131 consensus.fPowNoRetargeting = false;
132 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
133 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
134 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
135 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
136 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1815; // 90%
137 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
138
139 ApplyDeploymentOptions(opts.dep_opts);
140
141 consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000001128750f82f4c366153a3a030"};
142 consensus.defaultAssumeValid = uint256{"00000000000000000000ccebd6d74d9194d8dcdc1d177c478e094bfad51ba5ac"}; // 938343
143
144 /**
145 * The message start string is designed to be unlikely to occur in normal data.
146 * The characters are rarely used upper ASCII, not valid as UTF-8, and produce
147 * a large 32-bit integer with any alignment.
148 */
149 pchMessageStart[0] = 0xf9;
150 pchMessageStart[1] = 0xbe;
151 pchMessageStart[2] = 0xb4;
152 pchMessageStart[3] = 0xd9;
153 nDefaultPort = 8333;
154 nPruneAfterHeight = 100000;
155 m_assumed_blockchain_size = 856;
156 m_assumed_chain_state_size = 14;
157
158 genesis = CreateGenesisBlock(1231006505, 2083236893, 0x1d00ffff, 1, 50 * COIN);
159 consensus.hashGenesisBlock = genesis.GetHash();
160 assert(consensus.hashGenesisBlock == uint256{"000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"});
161 assert(genesis.hashMerkleRoot == uint256{"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"});
162
163 // Note that of those which support the service bits prefix, most only support a subset of
164 // possible options.
165 // This is fine at runtime as we'll fall back to using them as an addrfetch if they don't support the
166 // service bits we want, but we should get them updated to support all service bits wanted by any
167 // release ASAP to avoid it where possible.
168 vSeeds.emplace_back("dnsseed.bluematt.me."); // Matt Corallo, only supports x9
169 vSeeds.emplace_back("seed.bitcoin.jonasschnelli.ch."); // Jonas Schnelli, only supports x1, x5, x9, and xd
170 vSeeds.emplace_back("seed.btc.petertodd.net."); // Peter Todd, only supports x1, x5, x9, and xd
171 vSeeds.emplace_back("seed.bitcoin.sprovoost.nl."); // Sjors Provoost
172 vSeeds.emplace_back("dnsseed.emzy.de."); // Stephan Oeste
173 vSeeds.emplace_back("seed.bitcoin.wiz.biz."); // Jason Maurice
174 vSeeds.emplace_back("seed.mainnet.achownodes.xyz."); // Ava Chow, only supports x1, x5, x9, x49, x809, x849, xd, x400, x404, x408, x448, xc08, xc48, x40c
175
176 base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,0);
177 base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,5);
178 base58Prefixes[SECRET_KEY] = std::vector<unsigned char>(1,128);
179 base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x88, 0xB2, 0x1E};
180 base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x88, 0xAD, 0xE4};
181
182 bech32_hrp = "bc";
183
184 vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_main), std::end(chainparams_seed_main));
185
186 fDefaultConsistencyChecks = false;
187 m_is_mockable_chain = false;
188
189 m_assumeutxo_data = {
190 {
191 .height = 840'000,
192 .hash_serialized = AssumeutxoHash{uint256{"a2a5521b1b5ab65f67818e5e8eccabb7171a517f9e2382208f77687310768f96"}},
193 .m_chain_tx_count = 991032194,
194 .blockhash = uint256{"0000000000000000000320283a032748cef8227873ff4872689bf23f1cda83a5"},
195 },
196 {
197 .height = 880'000,
198 .hash_serialized = AssumeutxoHash{uint256{"dbd190983eaf433ef7c15f78a278ae42c00ef52e0fd2a54953782175fbadcea9"}},
199 .m_chain_tx_count = 1145604538,
200 .blockhash = uint256{"000000000000000000010b17283c3c400507969a9c2afd1dcf2082ec5cca2880"},
201 },
202 {
203 .height = 910'000,
204 .hash_serialized = AssumeutxoHash{uint256{"4daf8a17b4902498c5787966a2b51c613acdab5df5db73f196fa59a4da2f1568"}},
205 .m_chain_tx_count = 1226586151,
206 .blockhash = uint256{"0000000000000000000108970acb9522ffd516eae17acddcb1bd16469194a821"},
207 },
208 {
209 .height = 935'000,
210 .hash_serialized = AssumeutxoHash{uint256{"e4b90ef9eae834f56c4b64d2d50143cee10ad87994c614d7d04125e2a6025050"}},
211 .m_chain_tx_count = 1305397408,
212 .blockhash = uint256{"0000000000000000000147034958af1652b2b91bba607beacc5e72a56f0fb5ee"},
213 }
214 };
215
216 chainTxData = ChainTxData{
217 // Data from RPC: getchaintxstats 4096 00000000000000000000ccebd6d74d9194d8dcdc1d177c478e094bfad51ba5ac
218 .nTime = 1772055173,
219 .tx_count = 1315805869,
220 .dTxRate = 5.40111006496122,
221 };
222
223 // Generated by headerssync-params.py on 2026-02-25.
224 m_headers_sync_params = HeadersSyncParams{
225 .commitment_period = 641,
226 .redownload_buffer_size = 15218, // 15218/641 = ~23.7 commitments
227 };
228 }
229 };
230
231 /**
232 * Testnet (v3): public test network which is reset from time to time.
233 */
234 class CTestNetParams : public CChainParams {
235 public:
236 CTestNetParams(const TestNetOptions& opts) {
237 m_chain_type = ChainType::TESTNET;
238 consensus.signet_blocks = false;
239 consensus.signet_challenge.clear();
240 consensus.nSubsidyHalvingInterval = 210000;
241 consensus.script_flag_exceptions.emplace( // BIP16 exception
242 uint256{"00000000dd30457c001f4095d208cc1296b0eed002427aa599874af7a432b105"}, SCRIPT_VERIFY_NONE);
243 consensus.BIP34Height = 21111;
244 consensus.BIP34Hash = uint256{"0000000023b3a96d3484e5abb3755c413e7d41500f8e2a5c3f0dd01299cd8ef8"};
245 consensus.BIP65Height = 581885; // 00000000007f6655f22f98e72ed80d8b06dc761d5da09df0fa1dc4be4f861eb6
246 consensus.BIP66Height = 330776; // 000000002104c8c45e99a8853285a3b592602a3ccde2b832481da85e9e4ba182
247 consensus.CSVHeight = 770112; // 00000000025e930139bac5c6c31a403776da130831ab85be56578f3fa75369bb
248 consensus.SegwitHeight = 834624; // 00000000002b980fcd729daaa248fd9316a5200e9b367f4ff2c42453e84201ca
249 consensus.MinBIP9WarningHeight = 2013984; // taproot activation height + miner confirmation window
250 consensus.powLimit = uint256{"00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"};
251 consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
252 consensus.nPowTargetSpacing = 10 * 60;
253 consensus.fPowAllowMinDifficultyBlocks = true;
254 consensus.enforce_BIP94 = false;
255 consensus.fPowNoRetargeting = false;
256 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
257 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
258 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
259 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
260 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1512; // 75%
261 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
262
263 ApplyDeploymentOptions(opts.dep_opts);
264
265 consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000017dde1c649f3708d14b6"};
266 consensus.defaultAssumeValid = uint256{"000000007a61e4230b28ac5cb6b5e5a0130de37ac1faf2f8987d2fa6505b67f4"}; // 4842348
267
268 pchMessageStart[0] = 0x0b;
269 pchMessageStart[1] = 0x11;
270 pchMessageStart[2] = 0x09;
271 pchMessageStart[3] = 0x07;
272 nDefaultPort = 18333;
273 nPruneAfterHeight = 1000;
274 m_assumed_blockchain_size = 245;
275 m_assumed_chain_state_size = 19;
276
277 genesis = CreateGenesisBlock(1296688602, 414098458, 0x1d00ffff, 1, 50 * COIN);
278 consensus.hashGenesisBlock = genesis.GetHash();
279 assert(consensus.hashGenesisBlock == uint256{"000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"});
280 assert(genesis.hashMerkleRoot == uint256{"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"});
281
282 vFixedSeeds.clear();
283 vSeeds.clear();
284 // nodes with support for servicebits filtering should be at the top
285 vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch.");
286 vSeeds.emplace_back("seed.tbtc.petertodd.net.");
287 vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl.");
288 vSeeds.emplace_back("testnet-seed.bluematt.me."); // Just a static list of stable node(s), only supports x9
289 vSeeds.emplace_back("seed.testnet.achownodes.xyz."); // Ava Chow, only supports x1, x5, x9, x49, x809, x849, xd, x400, x404, x408, x448, xc08, xc48, x40c
290
291 base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
292 base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
293 base58Prefixes[SECRET_KEY] = std::vector<unsigned char>(1,239);
294 base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
295 base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
296
297 bech32_hrp = "tb";
298
299 vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_test), std::end(chainparams_seed_test));
300
301 fDefaultConsistencyChecks = false;
302 m_is_mockable_chain = false;
303
304 m_assumeutxo_data = {
305 {
306 .height = 2'500'000,
307 .hash_serialized = AssumeutxoHash{uint256{"f841584909f68e47897952345234e37fcd9128cd818f41ee6c3ca68db8071be7"}},
308 .m_chain_tx_count = 66484552,
309 .blockhash = uint256{"0000000000000093bcb68c03a9a168ae252572d348a2eaeba2cdf9231d73206f"},
310 },
311 {
312 .height = 4'840'000,
313 .hash_serialized = AssumeutxoHash{uint256{"ce6bb677bb2ee9789c4a1c9d73e6683c53fc20e8fdbedbdaaf468982a0c8db2a"}},
314 .m_chain_tx_count = 536078574,
315 .blockhash = uint256{"00000000000000f4971a7fb37fbdff89315b69a2e1920c467654a382f0d64786"},
316 }
317 };
318
319 chainTxData = ChainTxData{
320 // Data from RPC: getchaintxstats 4096 000000007a61e4230b28ac5cb6b5e5a0130de37ac1faf2f8987d2fa6505b67f4
321 .nTime = 1772051651,
322 .tx_count = 536108416,
323 .dTxRate = 0.02691479016257117,
324 };
325
326 // Generated by headerssync-params.py on 2026-02-25.
327 m_headers_sync_params = HeadersSyncParams{
328 .commitment_period = 673,
329 .redownload_buffer_size = 14460, // 14460/673 = ~21.5 commitments
330 };
331 }
332 };
333
334 /**
335 * Testnet (v4): public test network which is reset from time to time.
336 */
337 class CTestNet4Params : public CChainParams {
338 public:
339 CTestNet4Params(const TestNetOptions& opts) {
340 m_chain_type = ChainType::TESTNET4;
341 consensus.signet_blocks = false;
342 consensus.signet_challenge.clear();
343 consensus.nSubsidyHalvingInterval = 210000;
344 consensus.BIP34Height = 1;
345 consensus.BIP34Hash = uint256{};
346 consensus.BIP65Height = 1;
347 consensus.BIP66Height = 1;
348 consensus.CSVHeight = 1;
349 consensus.SegwitHeight = 1;
350 consensus.MinBIP9WarningHeight = 0;
351 consensus.powLimit = uint256{"00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"};
352 consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
353 consensus.nPowTargetSpacing = 10 * 60;
354 consensus.fPowAllowMinDifficultyBlocks = true;
355 consensus.enforce_BIP94 = true;
356 consensus.fPowNoRetargeting = false;
357
358 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
359 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
360 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
361 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
362 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1512; // 75%
363 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
364
365 ApplyDeploymentOptions(opts.dep_opts);
366
367 consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000009a0fe15d0177d086304"};
368 consensus.defaultAssumeValid = uint256{"0000000002368b1e4ee27e2e85676ae6f9f9e69579b29093e9a82c170bf7cf8a"}; // 123613
369
370 pchMessageStart[0] = 0x1c;
371 pchMessageStart[1] = 0x16;
372 pchMessageStart[2] = 0x3f;
373 pchMessageStart[3] = 0x28;
374 nDefaultPort = 48333;
375 nPruneAfterHeight = 1000;
376 m_assumed_blockchain_size = 31;
377 m_assumed_chain_state_size = 2;
378
379 const char* testnet4_genesis_msg = "03/May/2024 000000000000000000001ebd58c244970b3aa9d783bb001011fbe8ea8e98e00e";
380 const CScript testnet4_genesis_script = CScript() << "000000000000000000000000000000000000000000000000000000000000000000"_hex << OP_CHECKSIG;
381 genesis = CreateGenesisBlock(testnet4_genesis_msg,
382 testnet4_genesis_script,
383 1714777860,
384 393743547,
385 0x1d00ffff,
386 1,
387 50 * COIN);
388 consensus.hashGenesisBlock = genesis.GetHash();
389 assert(consensus.hashGenesisBlock == uint256{"00000000da84f2bafbbc53dee25a72ae507ff4914b867c565be350b0da8bf043"});
390 assert(genesis.hashMerkleRoot == uint256{"7aa0a7ae1e223414cb807e40cd57e667b718e42aaf9306db9102fe28912b7b4e"});
391
392 vFixedSeeds.clear();
393 vSeeds.clear();
394 // nodes with support for servicebits filtering should be at the top
395 vSeeds.emplace_back("seed.testnet4.bitcoin.sprovoost.nl."); // Sjors Provoost
396 vSeeds.emplace_back("seed.testnet4.wiz.biz."); // Jason Maurice
397
398 base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
399 base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
400 base58Prefixes[SECRET_KEY] = std::vector<unsigned char>(1,239);
401 base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
402 base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
403
404 bech32_hrp = "tb";
405
406 vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_testnet4), std::end(chainparams_seed_testnet4));
407
408 fDefaultConsistencyChecks = false;
409 m_is_mockable_chain = false;
410
411 m_assumeutxo_data = {
412 {
413 .height = 90'000,
414 .hash_serialized = AssumeutxoHash{uint256{"784fb5e98241de66fdd429f4392155c9e7db5c017148e66e8fdbc95746f8b9b5"}},
415 .m_chain_tx_count = 11347043,
416 .blockhash = uint256{"0000000002ebe8bcda020e0dd6ccfbdfac531d2f6a81457191b99fc2df2dbe3b"},
417 },
418 {
419 .height = 120'000,
420 .hash_serialized = AssumeutxoHash{uint256{"10b05d05ad468d0971162e1b222a4aa66caca89da2bb2a93f8f37fb29c4794b0"}},
421 .m_chain_tx_count = 14141057,
422 .blockhash = uint256{"000000000bd2317e51b3c5794981c35ba894ce27d3e772d5c39ecd9cbce01dc8"},
423 }
424 };
425
426 chainTxData = ChainTxData{
427 // Data from RPC: getchaintxstats 4096 0000000002368b1e4ee27e2e85676ae6f9f9e69579b29093e9a82c170bf7cf8a
428 .nTime = 1772013387,
429 .tx_count = 14191421,
430 .dTxRate = 0.01848579579528412,
431 };
432
433 // Generated by headerssync-params.py on 2026-02-25.
434 m_headers_sync_params = HeadersSyncParams{
435 .commitment_period = 606,
436 .redownload_buffer_size = 16092, // 16092/606 = ~26.6 commitments
437 };
438 }
439 };
440
441 /**
442 * Signet: test network with an additional consensus parameter (see BIP325).
443 */
444 class SigNetParams : public CChainParams {
445 public:
446 explicit SigNetParams(const SigNetOptions& options)
447 {
448 std::vector<uint8_t> bin;
449 vFixedSeeds.clear();
450 vSeeds.clear();
451
452 if (!options.challenge) {
453 bin = "512103ad5e0edad18cb1f0fc0d28a3d4f1f3e445640337489abb10404f2d1e086be430210359ef5021964fe22d6f8e05b2463c9540ce96883fe3b278760f048f5189f2e6c452ae"_hex_v_u8;
454 vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_signet), std::end(chainparams_seed_signet));
455 vSeeds.emplace_back("seed.signet.bitcoin.sprovoost.nl.");
456 vSeeds.emplace_back("seed.signet.achownodes.xyz."); // Ava Chow, only supports x1, x5, x9, x49, x809, x849, xd, x400, x404, x408, x448, xc08, xc48, x40c
457
458 consensus.nMinimumChainWork = uint256{"00000000000000000000000000000000000000000000000000000b463ea0a4b8"};
459 consensus.defaultAssumeValid = uint256{"00000008414aab61092ef93f1aacc54cf9e9f16af29ddad493b908a01ff5c329"}; // 293175
460 m_assumed_blockchain_size = 24;
461 m_assumed_chain_state_size = 4;
462 chainTxData = ChainTxData{
463 // Data from RPC: getchaintxstats 4096 00000008414aab61092ef93f1aacc54cf9e9f16af29ddad493b908a01ff5c329
464 .nTime = 1772055248,
465 .tx_count = 28676833,
466 .dTxRate = 0.06736623436338929,
467 };
468 } else {
469 bin = *options.challenge;
470 consensus.nMinimumChainWork = uint256{};
471 consensus.defaultAssumeValid = uint256{};
472 m_assumed_blockchain_size = 0;
473 m_assumed_chain_state_size = 0;
474 chainTxData = ChainTxData{
475 0,
476 0,
477 0,
478 };
479 LogInfo("Signet with challenge %s", HexStr(bin));
480 }
481
482 if (options.seeds) {
483 vSeeds = *options.seeds;
484 }
485
486 m_chain_type = ChainType::SIGNET;
487 consensus.signet_blocks = true;
488 consensus.signet_challenge.assign(bin.begin(), bin.end());
489 consensus.nSubsidyHalvingInterval = 210000;
490 consensus.BIP34Height = 1;
491 consensus.BIP34Hash = uint256{};
492 consensus.BIP65Height = 1;
493 consensus.BIP66Height = 1;
494 consensus.CSVHeight = 1;
495 consensus.SegwitHeight = 1;
496 consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
497 consensus.nPowTargetSpacing = 10 * 60;
498 consensus.fPowAllowMinDifficultyBlocks = false;
499 consensus.enforce_BIP94 = false;
500 consensus.fPowNoRetargeting = false;
501 consensus.MinBIP9WarningHeight = 0;
502 consensus.powLimit = uint256{"00000377ae000000000000000000000000000000000000000000000000000000"};
503 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
504 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
505 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
506 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
507 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1815; // 90%
508 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
509
510 ApplyDeploymentOptions(options.dep_opts);
511
512 // message start is defined as the first 4 bytes of the sha256d of the block script
513 HashWriter h{};
514 h << consensus.signet_challenge;
515 uint256 hash = h.GetHash();
516 std::copy_n(hash.begin(), 4, pchMessageStart.begin());
517
518 nDefaultPort = 38333;
519 nPruneAfterHeight = 1000;
520
521 genesis = CreateGenesisBlock(1598918400, 52613770, 0x1e0377ae, 1, 50 * COIN);
522 consensus.hashGenesisBlock = genesis.GetHash();
523 assert(consensus.hashGenesisBlock == uint256{"00000008819873e925422c1ff0f99f7cc9bbb232af63a077a480a3633bee1ef6"});
524 assert(genesis.hashMerkleRoot == uint256{"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"});
525
526 m_assumeutxo_data = {
527 {
528 .height = 160'000,
529 .hash_serialized = AssumeutxoHash{uint256{"fe0a44309b74d6b5883d246cb419c6221bcccf0b308c9b59b7d70783dbdf928a"}},
530 .m_chain_tx_count = 2289496,
531 .blockhash = uint256{"0000003ca3c99aff040f2563c2ad8f8ec88bd0fd6b8f0895cfaf1ef90353a62c"},
532 },
533 {
534 .height = 290'000,
535 .hash_serialized = AssumeutxoHash{uint256{"97267e000b4b876800167e71b9123f1529d13b14308abec2888bbd2160d14545"}},
536 .m_chain_tx_count = 28547497,
537 .blockhash = uint256{"0000000577f2741bb30cd9d39d6d71b023afbeb9764f6260786a97969d5c9ac0"},
538 }
539 };
540
541 base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
542 base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
543 base58Prefixes[SECRET_KEY] = std::vector<unsigned char>(1,239);
544 base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
545 base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
546
547 bech32_hrp = "tb";
548
549 fDefaultConsistencyChecks = false;
550 m_is_mockable_chain = false;
551
552 // Generated by headerssync-params.py on 2026-02-25.
553 m_headers_sync_params = HeadersSyncParams{
554 .commitment_period = 620,
555 .redownload_buffer_size = 15724, // 15724/620 = ~25.4 commitments
556 };
557 }
558 };
559
560 /**
561 * Regression test: intended for private networks only. Has minimal difficulty to ensure that
562 * blocks can be found instantly.
563 */
564 class CRegTestParams : public CChainParams
565 {
566 public:
567 explicit CRegTestParams(const RegTestOptions& opts)
568 {
569 m_chain_type = ChainType::REGTEST;
570 consensus.signet_blocks = false;
571 consensus.signet_challenge.clear();
572 consensus.nSubsidyHalvingInterval = 150;
573 consensus.BIP34Height = 1; // Always active unless overridden
574 consensus.BIP34Hash = uint256();
575 consensus.BIP65Height = 1; // Always active unless overridden
576 consensus.BIP66Height = 1; // Always active unless overridden
577 consensus.CSVHeight = 1; // Always active unless overridden
578 consensus.SegwitHeight = 0; // Always active unless overridden
579 consensus.MinBIP9WarningHeight = 0;
580 consensus.powLimit = uint256{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"};
581 consensus.nPowTargetTimespan = 24 * 60 * 60; // one day
582 consensus.nPowTargetSpacing = 10 * 60;
583 consensus.fPowAllowMinDifficultyBlocks = true;
584 consensus.enforce_BIP94 = opts.enforce_bip94;
585 consensus.fPowNoRetargeting = true;
586
587 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
588 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
589 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
590 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
591 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 108; // 75%
592 consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 144; // Faster than normal for regtest (144 instead of 2016)
593
594 consensus.nMinimumChainWork = uint256{};
595 consensus.defaultAssumeValid = uint256{};
596
597 pchMessageStart[0] = 0xfa;
598 pchMessageStart[1] = 0xbf;
599 pchMessageStart[2] = 0xb5;
600 pchMessageStart[3] = 0xda;
601 nDefaultPort = 18444;
602 nPruneAfterHeight = opts.fastprune ? 100 : 1000;
603 m_assumed_blockchain_size = 0;
604 m_assumed_chain_state_size = 0;
605
606 ApplyDeploymentOptions(opts.dep_opts);
607
608 genesis = CreateGenesisBlock(1296688602, 2, 0x207fffff, 1, 50 * COIN);
609 consensus.hashGenesisBlock = genesis.GetHash();
610 assert(consensus.hashGenesisBlock == uint256{"0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"});
611 assert(genesis.hashMerkleRoot == uint256{"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"});
612
613 vFixedSeeds.clear(); //!< Regtest mode doesn't have any fixed seeds.
614 vSeeds.clear();
615 vSeeds.emplace_back("dummySeed.invalid.");
616
617 fDefaultConsistencyChecks = true;
618 m_is_mockable_chain = true;
619
620 m_assumeutxo_data = {
621 { // For use by unit tests
622 .height = 110,
623 .hash_serialized = AssumeutxoHash{uint256{"86e9a1205b418b16dde3a18a78c730e30137e28466bda5dbf6b33ab8fc05447c"}},
624 .m_chain_tx_count = 111,
625 .blockhash = uint256{"135eec25a6fb277884e5824e7aa7d052c4868161c99a5122170b5266f86c273d"},
626 },
627 {
628 // For use by fuzz target src/test/fuzz/utxo_snapshot.cpp
629 .height = 200,
630 .hash_serialized = AssumeutxoHash{uint256{"17dcc016d188d16068907cdeb38b75691a118d43053b8cd6a25969419381d13a"}},
631 .m_chain_tx_count = 201,
632 .blockhash = uint256{"385901ccbd69dff6bbd00065d01fb8a9e464dede7cfe0372443884f9b1dcf6b9"},
633 },
634 {
635 // For use by test/functional/feature_assumeutxo.py and test/functional/tool_bitcoin_chainstate.py
636 .height = 299,
637 .hash_serialized = AssumeutxoHash{uint256{"106b2c56233e378a824cf0d5ff2be42ed32c72f1605c9be288d00942908a40ac"}},
638 .m_chain_tx_count = 334,
639 .blockhash = uint256{"0c552ced4721c249a389eb9b08cb8da261cd46f0e7b5f9d064d48f3113406853"},
640 },
641 };
642
643 chainTxData = ChainTxData{
644 .nTime = 0,
645 .tx_count = 0,
646 .dTxRate = 0.001, // Set a non-zero rate to make it testable
647 };
648
649 base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
650 base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
651 base58Prefixes[SECRET_KEY] = std::vector<unsigned char>(1,239);
652 base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
653 base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
654
655 bech32_hrp = "bcrt";
656
657 // Copied from Testnet4.
658 m_headers_sync_params = HeadersSyncParams{
659 .commitment_period = 275,
660 .redownload_buffer_size = 7017, // 7017/275 = ~25.5 commitments
661 };
662 }
663 };
664
665 std::unique_ptr<const CChainParams> CChainParams::SigNet(const SigNetOptions& options)
666 {
667 return std::make_unique<const SigNetParams>(options);
668 }
669
670 std::unique_ptr<const CChainParams> CChainParams::RegTest(const RegTestOptions& options)
671 {
672 return std::make_unique<const CRegTestParams>(options);
673 }
674
675 std::unique_ptr<const CChainParams> CChainParams::Main(const MainNetOptions& options)
676 {
677 return std::make_unique<const CMainParams>(options);
678 }
679
680 std::unique_ptr<const CChainParams> CChainParams::TestNet(const TestNetOptions& options)
681 {
682 return std::make_unique<const CTestNetParams>(options);
683 }
684
685 std::unique_ptr<const CChainParams> CChainParams::TestNet4(const TestNetOptions& options)
686 {
687 return std::make_unique<const CTestNet4Params>(options);
688 }
689
690 std::vector<int> CChainParams::GetAvailableSnapshotHeights() const
691 {
692 std::vector<int> heights;
693 heights.reserve(m_assumeutxo_data.size());
694
695 for (const auto& data : m_assumeutxo_data) {
696 heights.emplace_back(data.height);
697 }
698 return heights;
699 }
700
701 std::optional<ChainType> GetNetworkForMagic(const MessageStartChars& message)
702 {
703 const auto mainnet_msg = CChainParams::Main()->MessageStart();
704 const auto testnet_msg = CChainParams::TestNet()->MessageStart();
705 const auto testnet4_msg = CChainParams::TestNet4()->MessageStart();
706 const auto regtest_msg = CChainParams::RegTest()->MessageStart();
707 const auto signet_msg = CChainParams::SigNet()->MessageStart();
708
709 if (std::ranges::equal(message, mainnet_msg)) {
710 return ChainType::MAIN;
711 } else if (std::ranges::equal(message, testnet_msg)) {
712 return ChainType::TESTNET;
713 } else if (std::ranges::equal(message, testnet4_msg)) {
714 return ChainType::TESTNET4;
715 } else if (std::ranges::equal(message, regtest_msg)) {
716 return ChainType::REGTEST;
717 } else if (std::ranges::equal(message, signet_msg)) {
718 return ChainType::SIGNET;
719 }
720 return std::nullopt;
721 }
722