READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server340 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

8,939 bytes · SHA-256 d97670674ac3aa5b… · View upstream ↗

10.21.1 Release Notes
2====================
3
4Bitcoin Core version 0.21.1 is now available from:
5
6  <https://bitcoincore.org/bin/bitcoin-core-0.21.1/>
7
8This minor release includes various bug fixes and performance
9improvements, as well as updated translations.
10
11Please report bugs using the issue tracker at GitHub:
12
13  <https://github.com/bitcoin/bitcoin/issues>
14
15To receive security and update notifications, please subscribe to:
16
17  <https://bitcoincore.org/en/list/announcements/join/>
18
19How to Upgrade
20==============
21
22If you are running an older version, shut it down. Wait until it has completely
23shut down (which might take a few minutes in some cases), then run the
24installer (on Windows) or just copy over `/Applications/Bitcoin-Qt` (on Mac)
25or `bitcoind`/`bitcoin-qt` (on Linux).
26
27Upgrading directly from a version of Bitcoin Core that has reached its EOL is
28possible, but it might take some time if the data directory needs to be migrated. Old
29wallet versions of Bitcoin Core are generally supported.
30
31Compatibility
32==============
33
34Bitcoin Core is supported and extensively tested on operating systems
35using the Linux kernel, macOS 10.12+, and Windows 7 and newer.  Bitcoin
36Core should also work on most other Unix-like systems but is not as
37frequently tested on them.  It is not recommended to use Bitcoin Core on
38unsupported systems.
39
40From Bitcoin Core 0.20.0 onwards, macOS versions earlier than 10.12 are no
41longer supported. Additionally, Bitcoin Core does not yet change appearance
42when macOS "dark mode" is activated.
43
44Notable changes
45===============
46
47## Taproot Soft Fork
48
49Included in this release are the mainnet and testnet activation
50parameters for the taproot soft fork (BIP341) which also adds support
51for schnorr signatures (BIP340) and tapscript (BIP342).
52
53If activated, these improvements will allow users of single-signature
54scripts, multisignature scripts, and complex contracts to all use
55identical-appearing commitments that enhance their privacy and the
56fungibility of all bitcoins. Spenders will enjoy lower fees and the
57ability to resolve many multisig scripts and complex contracts with the
58same efficiency, low fees, and large anonymity set as single-sig users.
59Taproot and schnorr also include efficiency improvements for full nodes
60such as the ability to batch signature verification.  Together, the
61improvements lay the groundwork for future potential
62upgrades that may improve efficiency, privacy, and fungibility further.
63
64Activation for taproot is being managed using a variation of BIP9
65versionbits called Speedy Trial (described in BIP341). Taproot's
66versionbit is bit 2, and nodes will begin tracking which blocks signal
67support for taproot at the beginning of the first retarget period after
68taproot’s start date of 24 April 2021.  If 90% of blocks within a
692,016-block retarget period (about two weeks) signal support for taproot
70prior to the first retarget period beginning after the time of 11 August
712021, the soft fork will be locked in, and taproot will then be active
72as of block 709632 (expected in early or mid November).
73
74Should taproot not be locked in via Speedy Trial activation, it is
75expected that a follow-up activation mechanism will be deployed, with
76changes to address the reasons the Speedy Trial method failed.
77
78This release includes the ability to pay taproot addresses, although
79payments to such addresses are not secure until taproot activates.
80It also includes the ability to relay and mine taproot transactions
81after activation.  Beyond those two basic capabilities, this release
82does not include any code that allows anyone to directly use taproot.
83The addition of taproot-related features to Bitcoin Core's wallet is
84expected in later releases once taproot activation is assured.
85
86All users, businesses, and miners are encouraged to upgrade to this
87release (or a subsequent compatible release) unless they object to
88activation of taproot.  If taproot is locked in, then upgrading before
89block 709632 is highly recommended to help enforce taproot's new rules
90and to avoid the unlikely case of seeing falsely confirmed transactions.
91
92Miners who want to activate Taproot should preferably use this release
93to control their signaling.  The `getblocktemplate` RPC results will
94automatically be updated to signal once the appropriate start has been
95reached and continue signaling until the timeout occurs or taproot
96activates.  Alternatively, miners may manually start signaling on bit 2
97at any time; if taproot activates, they will need to ensure they update
98their nodes before block 709632 or non-upgraded nodes could cause them to mine on
99an invalid chain.  See the [versionbits
100FAQ](https://bitcoincore.org/en/2016/06/08/version-bits-miners-faq/) for
101details.
102
103
104For more information about taproot, please see the following resources:
105
106- Technical specifications
107  - [BIP340 Schnorr signatures for secp256k1](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki) 
108  - [BIP341 Taproot: SegWit version 1 spending rules](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki)
109  - [BIP342 Validation of Taproot scripts](https://github.com/bitcoin/bips/blob/master/bip-0342.mediawiki)
110
111- Popular articles;
112  - [Taproot Is Coming: What It Is, and How It Will Benefit Bitcoin](https://bitcoinmagazine.com/technical/taproot-coming-what-it-and-how-it-will-benefit-bitcoin)
113  - [What do Schnorr Signatures Mean for Bitcoin?](https://academy.binance.com/en/articles/what-do-schnorr-signatures-mean-for-bitcoin)
114  - [The Schnorr Signature & Taproot Softfork Proposal](https://blog.bitmex.com/the-schnorr-signature-taproot-softfork-proposal/)
115
116- Development history overview
117  - [Taproot](https://bitcoinops.org/en/topics/taproot/)
118  - [Schnorr signatures](https://bitcoinops.org/en/topics/schnorr-signatures/)
119  - [Tapscript](https://bitcoinops.org/en/topics/tapscript/)
120  - [Soft fork activation](https://bitcoinops.org/en/topics/soft-fork-activation/)
121
122- Other
123  - [Questions and answers related to taproot](https://bitcoin.stackexchange.com/questions/tagged/taproot)
124  - [Taproot review](https://github.com/ajtowns/taproot-review)
125
126Updated RPCs
127------------
128
129- Due to [BIP 350](https://github.com/bitcoin/bips/blob/master/bip-0350.mediawiki)
130  being implemented, behavior for all RPCs that accept addresses is changed when
131  a native witness version 1 (or higher) is passed. These now require a Bech32m
132  encoding instead of a Bech32 one, and Bech32m encoding will be used for such
133  addresses in RPC output as well. No version 1 addresses should be created
134  for mainnet until consensus rules are adopted that give them meaning
135  (e.g. through [BIP 341](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki)).
136  Once that happens, Bech32m is expected to be used for them, so this shouldn't
137  affect any production systems, but may be observed on other networks where such
138  addresses already have meaning (like signet).
139
1400.21.1 change log
141=================
142
143### Consensus
144- #21377 Speedy trial support for versionbits (ajtowns)
145- #21686 Speedy trial activation parameters for Taproot (achow101)
146
147### P2P protocol and network code
148- #20852 allow CSubNet of non-IP networks (vasild)
149- #21043 Avoid UBSan warning in ProcessMessage(…) (practicalswift)
150
151### Wallet
152- #21166 Introduce DeferredSignatureChecker and have SignatureExtractorClass subclass it (achow101)
153- #21083 Avoid requesting fee rates multiple times during coin selection (achow101)
154
155### RPC and other APIs
156- #21201 Disallow sendtoaddress and sendmany when private keys disabled (achow101)
157
158### Build system
159- #21486 link against -lsocket if required for `*ifaddrs` (fanquake)
160- #20983 Fix MSVC build after gui#176 (hebasto)
161
162### Tests and QA
163- #21380 Add fuzzing harness for versionbits (ajtowns)
164- #20812 fuzz: Bump FuzzedDataProvider.h (MarcoFalke)
165- #20740 fuzz: Update FuzzedDataProvider.h from upstream (LLVM) (practicalswift)
166- #21446 Update vcpkg checkout commit (sipsorcery)
167- #21397 fuzz: Bump FuzzedDataProvider.h (MarcoFalke)
168- #21081 Fix the unreachable code at `feature_taproot` (brunoerg)
169- #20562 Test that a fully signed tx given to signrawtx is unchanged (achow101)
170- #21571 Make sure non-IP peers get discouraged and disconnected (vasild, MarcoFalke)
171- #21489 fuzz: cleanups for versionbits fuzzer (ajtowns)
172
173### Miscellaneous
174- #20861 BIP 350: Implement Bech32m and use it for v1+ segwit addresses (sipa)
175
176### Documentation
177- #21384 add signet to bitcoin.conf documentation (jonatack)
178- #21342 Remove outdated comment (hebasto)
179
180Credits
181=======
182
183Thanks to everyone who directly contributed to this release:
184
185- Aaron Clauson
186- Andrew Chow
187- Anthony Towns
188- Bruno Garcia
189- Fabian Jahr
190- fanquake
191- Hennadii Stepanov
192- Jon Atack
193- Luke Dashjr
194- MarcoFalke
195- Pieter Wuille
196- practicalswift
197- randymcmillan
198- Sjors Provoost
199- Vasil Dimov
200- W. J. van der Laan
201
202As well as to everyone that helped with translations on
203[Transifex](https://www.transifex.com/bitcoin/bitcoin/).
204

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.