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.

9,467 bytes · SHA-256 11de8a8a405ff8d7… · View upstream ↗

1Bitcoin Core version 0.11.2 is now available from:
2
3  <https://bitcoin.org/bin/bitcoin-core-0.11.2/>
4
5This is a new minor version release, bringing bug fixes, the BIP65
6(CLTV) consensus change, and relay policy preparation for BIP113. It is
7recommended to upgrade to this version as soon as possible.
8
9Please report bugs using the issue tracker at github:
10
11  <https://github.com/bitcoin/bitcoin/issues>
12
13Upgrading and downgrading
14=========================
15
16How to Upgrade
17--------------
18
19If you are running an older version, shut it down. Wait until it has completely
20shut down (which might take a few minutes for older versions), then run the
21installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
22bitcoind/bitcoin-qt (on Linux).
23
24Downgrade warning
25------------------
26
27Because release 0.10.0 and later makes use of headers-first synchronization and
28parallel block download (see further), the block files and databases are not
29backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:
30
31* Blocks will be stored on disk out of order (in the order they are
32received, really), which makes it incompatible with some tools or
33other programs. Reindexing using earlier versions will also not work
34anymore as a result of this.
35
36* The block index database will now hold headers for which no block is
37stored on disk, which earlier versions won't support.
38
39If you want to be able to downgrade smoothly, make a backup of your entire data
40directory. Without this your node will need start syncing (or importing from
41bootstrap.dat) anew afterwards. It is possible that the data from a completely
42synchronised 0.10 node may be usable in older versions as-is, but this is not
43supported and may break as soon as the older version attempts to reindex.
44
45This does not affect wallet forward or backward compatibility. There are no
46known problems when downgrading from 0.11.x to 0.10.x.
47
48Notable changes since 0.11.1
49============================
50
51BIP65 soft fork to enforce OP_CHECKLOCKTIMEVERIFY opcode
52--------------------------------------------------------
53
54This release includes several changes related to the [BIP65][] soft fork
55which redefines the existing OP_NOP2 opcode as OP_CHECKLOCKTIMEVERIFY
56(CLTV) so that a transaction output can be made unspendable until a
57specified point in the future.
58
591. This release will only relay and mine transactions spending a CLTV
60   output if they comply with the BIP65 rules as provided in code.
61
622. This release will produce version 4 blocks by default. Please see the
63   *notice to miners* below.
64
653. Once 951 out of a sequence of 1,001 blocks on the local node's best block
66   chain contain version 4 (or higher) blocks, this release will no
67   longer accept new version 3 blocks and it will only accept version 4
68   blocks if they comply with the BIP65 rules for CLTV.
69
70For more information about the soft-forking change, please see
71<https://github.com/bitcoin/bitcoin/pull/6351>
72
73Graphs showing the progress towards block version 4 adoption may be
74found at the URLs below:
75
76- Block versions over the last 50,000 blocks as progress towards BIP65
77  consensus enforcement: <http://bitcoin.sipa.be/ver-50k.png>
78
79- Block versions over the last 2,000 blocks showing the days to the
80  earliest possible BIP65 consensus-enforced block: <http://bitcoin.sipa.be/ver-2k.png>
81
82**Notice to miners:** Bitcoin Core’s block templates are now for
83version 4 blocks only, and any mining software relying on its
84getblocktemplate must be updated in parallel to use libblkmaker either
85version 0.4.3 or any version from 0.5.2 onward.
86
87- If you are solo mining, this will affect you the moment you upgrade
88  Bitcoin Core, which must be done prior to BIP65 achieving its 951/1001
89  status.
90
91- If you are mining with the stratum mining protocol: this does not
92  affect you.
93
94- If you are mining with the getblocktemplate protocol to a pool: this
95  will affect you at the pool operator’s discretion, which must be no
96  later than BIP65 achieving its 951/1001 status.
97
98[BIP65]: https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki
99
100BIP113 mempool-only locktime enforcement using GetMedianTimePast()
101----------------------------------------------------------------
102
103Bitcoin transactions currently may specify a locktime indicating when
104they may be added to a valid block.  Current consensus rules require
105that blocks have a block header time greater than the locktime specified
106in any transaction in that block.
107
108Miners get to choose what time they use for their header time, with the
109consensus rule being that no node will accept a block whose time is more
110than two hours in the future.  This creates a incentive for miners to
111set their header times to future values in order to include locktimed
112transactions which weren't supposed to be included for up to two more
113hours.
114
115The consensus rules also specify that valid blocks may have a header
116time greater than that of the median of the 11 previous blocks.  This
117GetMedianTimePast() time has a key feature we generally associate with
118time: it can't go backwards.
119
120[BIP113][] specifies a soft fork (**not enforced in this release**) that
121weakens this perverse incentive for individual miners to use a future
122time by requiring that valid blocks have a computed GetMedianTimePast()
123greater than the locktime specified in any transaction in that block.
124
125Mempool inclusion rules currently require transactions to be valid for
126immediate inclusion in a block in order to be accepted into the mempool.
127This release begins applying the BIP113 rule to received transactions,
128so transaction whose time is greater than the GetMedianTimePast() will
129no longer be accepted into the mempool.
130
131**Implication for miners:** you will begin rejecting transactions that
132would not be valid under BIP113, which will prevent you from producing
133invalid blocks if/when BIP113 is enforced on the network. Any
134transactions which are valid under the current rules but not yet valid
135under the BIP113 rules will either be mined by other miners or delayed
136until they are valid under BIP113. Note, however, that time-based
137locktime transactions are more or less unseen on the network currently.
138
139**Implication for users:** GetMedianTimePast() always trails behind the
140current time, so a transaction locktime set to the present time will be
141rejected by nodes running this release until the median time moves
142forward. To compensate, subtract one hour (3,600 seconds) from your
143locktimes to allow those transactions to be included in mempools at
144approximately the expected time.
145
146[BIP113]: https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki
147
148Windows bug fix for corrupted UTXO database on unclean shutdowns
149----------------------------------------------------------------
150
151Several Windows users reported that they often need to reindex the
152entire blockchain after an unclean shutdown of Bitcoin Core on Windows
153(or an unclean shutdown of Windows itself). Although unclean shutdowns
154remain unsafe, this release no longer relies on memory-mapped files for
155the UTXO database, which significantly reduced the frequency of unclean
156shutdowns leading to required reindexes during testing.
157
158For more information, see: <https://github.com/bitcoin/bitcoin/pull/6917>
159
160Other fixes for database corruption on Windows are expected in the
161next major release.
162
1630.11.2 Change log
164=================
165
166Detailed release notes follow. This overview includes changes that affect
167behavior, not code moves, refactors and string updates. For convenience in locating
168the code changes and accompanying discussion, both the pull request and
169git merge commit are mentioned.
170
171- #6124 `684636b` Make CScriptNum() take nMaxNumSize as an argument
172- #6124 `4fa7a04` Replace NOP2 with CHECKLOCKTIMEVERIFY (BIP65)
173- #6124 `6ea5ca4` Enable CHECKLOCKTIMEVERIFY as a standard script verify flag
174- #6351 `5e82e1c` Add CHECKLOCKTIMEVERIFY (BIP65) soft-fork logic
175- #6353 `ba1da90` Show softfork status in getblockchaininfo
176- #6351 `6af25b0` Add BIP65 to getblockchaininfo softforks list
177- #6688 `01878c9` Fix locking in GetTransaction
178- #6653 `b3eaa30` [Qt] Raise debug window when requested
179- #6600 `1e672ae` Debian/Ubuntu: Include bitcoin-tx binary
180- #6600 `2394f4d` Debian/Ubuntu: Split bitcoin-tx into its own package
181- #5987 `33d6825` Bugfix: Allow mining on top of old tip blocks for testnet
182- #6852 `21e58b8` build: make sure OpenSSL heeds noexecstack
183- #6846 `af6edac` alias `-h` for `--help`
184- #6867 `95a5039` Set TCP_NODELAY on P2P sockets.
185- #6856 `dfe55bd` Do not allow blockfile pruning during reindex.
186- #6566 `a1d3c6f` Add rules--presently disabled--for using GetMedianTimePast as end point for lock-time calculations
187- #6566 `f720c5f` Enable policy enforcing GetMedianTimePast as the end point of lock-time constraints
188- #6917 `0af5b8e` leveldb: Win32WritableFile without memory mapping
189- #6948 `4e895b0` Always flush block and undo when switching to new file
190
191Credits
192=======
193
194Thanks to everyone who directly contributed to this release:
195
196- Alex Morcos
197- ฿tcDrak
198- Chris Kleeschulte
199- Daniel Cousens
200- Diego Viola
201- Eric Lombrozo
202- Esteban Ordano
203- Gregory Maxwell
204- Luke Dashjr
205- Marco Falke
206- Mark Friedenbach
207- Matt Corallo
208- Micha
209- Mitchell Cash
210- Peter Todd
211- Pieter Wuille
212- Wladimir J. van der Laan
213- Zak Wilcox
214
215And those who contributed additional code review and/or security research.
216
217As well as everyone that helped translating on [Transifex](https://www.transifex.com/projects/p/bitcoin/).
218

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.