Bitcoin Core installation binaries can be downloaded from bitcoincore.org and the source-code is available from the Bitcoin Core source repository.

0.21.0 Release Notes

Bitcoin Core version 0.21.0 is now available from:

https://bitcoincore.org/bin/bitcoin-core-0.21.0/

Download torrent

This release includes new features, various bug fixes and performance
improvements, as well as updated translations.

Please report bugs using the issue tracker at GitHub:

https://github.com/bitcoin/bitcoin/issues

To receive security and update notifications, please subscribe to:

https://bitcoincore.org/en/list/announcements/join/

How to Upgrade

If you are running an older version, shut it down. Wait until it has completely
shut down (which might take a few minutes in some cases), then run the
installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac)
or bitcoind/bitcoin-qt (on Linux).

Upgrading directly from a version of Bitcoin Core that has reached its EOL is
possible, but it might take some time if the data directory needs to be migrated. Old
wallet versions of Bitcoin Core are generally supported.

Compatibility

Bitcoin Core is supported and extensively tested on operating systems
using the Linux kernel, macOS 10.12+, and Windows 7 and newer. Bitcoin
Core should also work on most other Unix-like systems but is not as
frequently tested on them. It is not recommended to use Bitcoin Core on
unsupported systems.

From Bitcoin Core 0.20.0 onwards, macOS versions earlier than 10.12 are no
longer supported. Additionally, Bitcoin Core does not yet change appearance
when macOS “dark mode” is activated.

The node’s known peers are persisted to disk in a file called peers.dat. The
format of this file has been changed in a backwards-incompatible way in order to
accommodate the storage of Tor v3 and other BIP155 addresses. This means that if
the file is modified by 0.21.0 or newer then older versions will not be able to
read it. Those old versions, in the event of a downgrade, will log an error
message “Incorrect keysize in addrman deserialization” and will continue normal
operation as if the file was missing, creating a new empty one. (#19954, #20284)

Notable changes

P2P and network changes

The mempool now tracks whether transactions submitted via the wallet or RPCs
have been successfully broadcast. Every 10-15 minutes, the node will try to
announce unbroadcast transactions until a peer requests it via a getdata
message or the transaction is removed from the mempool for other reasons.
The node will not track the broadcast status of transactions submitted to the
node using P2P relay. This version reduces the initial broadcast guarantees
for wallet transactions submitted via P2P to a node running the wallet. (#18038)
The size of the set of transactions that peers have announced and we consider
for requests has been reduced from 100000 to 5000 (per peer), and further
announcements will be ignored when that limit is reached. If you need to dump
(very) large batches of transactions, exceptions can be made for trusted
peers using the “relay” network permission. For localhost for example it can
be enabled using the command line option -whitelist=relay@127.0.0.1.
(#19988)
This release adds support for Tor version 3 hidden services, and rumoring them
over the network to other peers using
BIP155.
Version 2 hidden services are still fully supported by Bitcoin Core, but the
Tor network will start
deprecating them in the
coming months. (#19954)
The Tor onion service that is automatically created by setting the
-listenonion configuration parameter will now be created as a Tor v3 service
instead of Tor v2. The private key that was used for Tor v2 (if any) will be
left untouched in the onion_private_key file in the data directory (see
-datadir) and can be removed if not needed. Bitcoin Core will no longer
attempt to read it. The private key for the Tor v3 service will be saved in a
file named onion_v3_private_key. To use the deprecated Tor v2 service (not
recommended), the onion_private_key can be copied over
onion_v3_private_key, e.g.
cp -f onion_private_key onion_v3_private_key. (#19954)
The client writes a file (anchors.dat) at shutdown with the network addresses
of the node’s two outbound block-relay-only peers (so called “anchors”). The
next time the node starts, it reads this file and attempts to reconnect to those
same two peers. This prevents an attacker from using node restarts to trigger a
complete change in peers, which would be something they could use as part of an
eclipse attack. (#17428)
This release adds support for serving
BIP157 compact
filters to peers on the network when enabled using
-blockfilterindex=1 -peerblockfilters=1. (#16442)
This release adds support for signets
(BIP325) in
addition to the existing mainnet, testnet, and regtest networks. Signets are
centrally-controlled test networks, allowing them to be more predictable
test environments than the older testnet. One public signet is maintained, and
selectable using -signet. It is also possible to create personal signets.
(#18267).
This release implements
BIP339
wtxid relay. When negotiated, transactions are announced using their wtxid
instead of their txid. (#18044).
This release implements the proposed Taproot consensus rules
(BIP341 and
BIP342),
without activation on mainnet. Experimentation with Taproot can be done on
signet, where its rules are already active. (#19553)

Updated RPCs

The getpeerinfo RPC has a new network field that provides the type of
network (“ipv4”, “ipv6”, or “onion”) that the peer connected through. (#20002)
The getpeerinfo RPC now has additional last_block and last_transaction
fields that return the UNIX epoch time of the last block and the last valid
transaction received from each peer. (#19731)
getnetworkinfo now returns two new fields, connections_in and
connections_out, that provide the number of inbound and outbound peer
connections. These new fields are in addition to the existing connections
field, which returns the total number of peer connections. (#19405)
Exposed transaction version numbers are now treated as unsigned 32-bit
integers instead of signed 32-bit integers. This matches their treatment in
consensus logic. Versions greater than 2 continue to be non-standard
(matching previous behavior of smaller than 1 or greater than 2 being
non-standard). Note that this includes the joinpsbt command, which combines
partially-signed transactions by selecting the highest version number.
(#16525)
getmempoolinfo now returns an additional unbroadcastcount field. The
mempool tracks locally submitted transactions until their initial broadcast
is acknowledged by a peer. This field returns the count of transactions
waiting for acknowledgement.
Mempool RPCs such as getmempoolentry and getrawmempool with
verbose=true now return an additional unbroadcast field. This indicates
whether initial broadcast of the transaction has been acknowledged by a
peer. getmempoolancestors and getmempooldescendants are also updated.
The getpeerinfo RPC no longer returns the banscore field unless the configuration
option -deprecatedrpc=banscore is used. The banscore field will be fully
removed in the next major release. (#19469)
The testmempoolaccept RPC returns vsize and a fees object with the base fee
if the transaction would pass validation. (#19940)
The getpeerinfo RPC now returns a connection_type field. This indicates
the type of connection established with the peer. It will return one of six
options. For more information, see the getpeerinfo help documentation.
(#19725)
The getpeerinfo RPC no longer returns the addnode field by default. This
field will be fully removed in the next major release. It can be accessed
with the configuration option -deprecatedrpc=getpeerinfo_addnode. However,
it is recommended to instead use the connection_type field (it will return
manual when addnode is true). (#19725)
The getpeerinfo RPC no longer returns the whitelisted field by default.
This field will be fully removed in the next major release. It can be accessed
with the configuration option -deprecatedrpc=getpeerinfo_whitelisted. However,
it is recommended to instead use the permissions field to understand if specific
privileges have been granted to the peer. (#19770)
The walletcreatefundedpsbt RPC call will now fail with
Insufficient funds when inputs are manually selected but are not enough to cover
the outputs and fee. Additional inputs can automatically be added through the
new add_inputs option. (#16377)
The fundrawtransaction RPC now supports add_inputs option that when false
prevents adding more inputs if necessary and consequently the RPC fails.

Changes to Wallet or GUI related RPCs can be found in the GUI or Wallet section below.

New RPCs

The getindexinfo RPC returns the actively running indices of the node,
including their current sync status and height. It also accepts an index_name
to specify returning the status of that index only. (#19550)

Build System

Updated settings

The same ZeroMQ notification (e.g. -zmqpubhashtx=address) can now be
specified multiple times to publish the same notification to different ZeroMQ
sockets. (#18309)
The -banscore configuration option, which modified the default threshold for
disconnecting and discouraging misbehaving peers, has been removed as part of
changes in 0.20.1 and in this release to the handling of misbehaving peers.
Refer to “Changes regarding misbehaving peers” in the 0.20.1 release notes for
details. (#19464)
The -debug=db logging category, which was deprecated in 0.20 and replaced by
-debug=walletdb to distinguish it from coindb, has been removed. (#19202)
A download permission has been extracted from the noban permission. For
compatibility, noban implies the download permission, but this may change
in future releases. Refer to the help of the affected settings -whitebind
and -whitelist for more details. (#19191)
Netmasks that contain 1-bits after 0-bits (the 1-bits are not contiguous on
the left side, e.g. 255.0.255.255) are no longer accepted. They are invalid
according to RFC 4632. Netmasks are used in the -rpcallowip and -whitelist
configuration options and in the setban RPC. (#19628)
The -blocksonly setting now completely disables fee estimation. (#18766)

Changes to Wallet or GUI related settings can be found in the GUI or Wallet section below.

Tools and Utilities

A new bitcoin-cli -netinfo command provides a network peer connections
dashboard that displays data from the getpeerinfo and getnetworkinfo RPCs
in a human-readable format. An optional integer argument from 0 to 4 may
be passed to see increasing levels of detail. (#19643)
A new bitcoin-cli -generate command, equivalent to RPC generatenewaddress
followed by generatetoaddress, can generate blocks for command line testing
purposes. This is a client-side version of the former generate RPC. See the
help for details. (#19133)
The bitcoin-cli -getinfo command now displays the wallet name and balance for
each of the loaded wallets when more than one is loaded (e.g. in multiwallet
mode) and a wallet is not specified with -rpcwallet. (#18594)
The connections field of bitcoin-cli -getinfo is now expanded to return a JSON
object with in, out and total numbers of peer connections. It previously
returned a single integer value for the total number of peer connections. (#19405)

New settings

The startupnotify option is used to specify a command to
execute when Bitcoin Core has finished with its startup
sequence. (#15367)

Wallet

Backwards compatibility has been dropped for two getaddressinfo RPC
deprecations, as notified in the 0.20 release notes. The deprecated label
field has been removed as well as the deprecated labels behavior of
returning a JSON object containing name and purpose key-value pairs. Since
0.20, the labels field returns a JSON array of label names. (#19200)
To improve wallet privacy, the frequency of wallet rebroadcast attempts is
reduced from approximately once every 15 minutes to once every 12-36 hours.
To maintain a similar level of guarantee for initial broadcast of wallet
transactions, the mempool tracks these transactions as a part of the newly
introduced unbroadcast set. See the “P2P and network changes” section for
more information on the unbroadcast set. (#18038)
The sendtoaddress and sendmany RPCs accept an optional verbose=True
argument to also return the fee reason about the sent tx. (#19501)
The wallet can create a transaction without change even when the keypool is
empty. Previously it failed. (#17219)
The -salvagewallet startup option has been removed. A new salvage command
has been added to the bitcoin-wallet tool which performs the salvage
operations that -salvagewallet did. (#18918)
A new configuration flag -maxapsfee has been added, which sets the max
allowed avoid partial spends (APS) fee. It defaults to 0 (i.e. fee is the
same with and without APS). Setting it to -1 will disable APS, unless
-avoidpartialspends is set. (#14582)
The wallet will now avoid partial spends (APS) by default, if this does not
result in a difference in fees compared to the non-APS variant. The allowed
fee threshold can be adjusted using the new -maxapsfee configuration
option. (#14582)
The createwallet, loadwallet, and unloadwallet RPCs now accept
load_on_startup options to modify the settings list. Unless these options
are explicitly set to true or false, the list is not modified, so the RPC
methods remain backwards compatible. (#15937)
A new send RPC with similar syntax to walletcreatefundedpsbt, including
support for coin selection and a custom fee rate, is added. The send RPC is
experimental and may change in subsequent releases. (#16378)
The estimate_mode parameter is now case-insensitive in the bumpfee,
fundrawtransaction, sendmany, sendtoaddress, send and
walletcreatefundedpsbt RPCs. (#11413)
The bumpfee RPC now uses conf_target rather than confTarget in the
options. (#11413)
fundrawtransaction and walletcreatefundedpsbt when used with the
lockUnspents argument now lock manually selected coins, in addition to
automatically selected coins. Note that locked coins are never used in
automatic coin selection, but can still be manually selected. (#18244)
The -zapwallettxes startup option has been removed and its functionality
removed from the wallet. This option was originally intended to allow for
rescuing wallets which were affected by a malleability attack. More recently,
it has been used in the fee bumping of transactions that did not signal RBF.
This functionality has been superseded with the abandon transaction feature. (#19671)
The error code when no wallet is loaded, but a wallet RPC is called, has been
changed from -32601 (method not found) to -18 (wallet not found).
(#20101)

Automatic wallet creation removed

Bitcoin Core will no longer automatically create new wallets on startup. It will
load existing wallets specified by -wallet options on the command line or in
bitcoin.conf or settings.json files. And by default it will also load a
top-level unnamed (“”) wallet. However, if specified wallets don’t exist,
Bitcoin Core will now just log warnings instead of creating new wallets with
new keys and addresses like previous releases did.

New wallets can be created through the GUI (which has a more prominent create
wallet option), through the bitcoin-cli createwallet or bitcoin-wallet create commands, or the createwallet RPC. (#15454, #20186)

Experimental Descriptor Wallets

Please note that Descriptor Wallets are still experimental and not all expected functionality
is available. Additionally there may be some bugs and current functions may change in the future.
Bugs and missing functionality can be reported to the issue tracker.

0.21 introduces a new type of wallet – Descriptor Wallets. Descriptor Wallets store
scriptPubKey information using output descriptors. This is in contrast to the Legacy Wallet
structure where keys are used to implicitly generate scriptPubKeys and addresses. Because of this
shift to being script based instead of key based, many of the confusing things that Legacy
Wallets do are not possible with Descriptor Wallets. Descriptor Wallets use a definition
of “mine” for scripts which is simpler and more intuitive than that used by Legacy Wallets.
Descriptor Wallets also uses different semantics for watch-only things and imports.

As Descriptor Wallets are a new type of wallet, their introduction does not affect existing wallets.
Users who already have a Bitcoin Core wallet can continue to use it as they did before without
any change in behavior. Newly created Legacy Wallets (which remains the default type of wallet) will
behave as they did in previous versions of Bitcoin Core.

The differences between Descriptor Wallets and Legacy Wallets are largely limited to non user facing
things. They are intended to behave similarly except for the import/export and watchonly functionality
as described below.

Creating Descriptor Wallets

Descriptor wallets are not the default type of wallet.

In the GUI, a checkbox has been added to the Create Wallet Dialog to indicate that a
Descriptor Wallet should be created. And a descriptors option has been added to createwallet RPC.
Setting descriptors to true will create a Descriptor Wallet instead of a Legacy Wallet.

Without those options being set, a Legacy Wallet will be created instead.

`IsMine` Semantics

IsMine refers to the function used to determine whether a script belongs to the wallet.
This is used to determine whether an output belongs to the wallet. IsMine in Legacy Wallets
returns true if the wallet would be able to sign an input that spends an output with that script.
Since keys can be involved in a variety of different scripts, this definition for IsMine can
lead to many unexpected scripts being considered part of the wallet.

With Descriptor Wallets, descriptors explicitly specify the set of scripts that are owned by
the wallet. Since descriptors are deterministic and easily enumerable, users will know exactly
what scripts the wallet will consider to belong to it. Additionally the implementation of IsMine
in Descriptor Wallets is far simpler than for Legacy Wallets. Notably, in Legacy Wallets, IsMine
allowed for users to take one type of address (e.g. P2PKH), mutate it into another address type
(e.g. P2WPKH), and the wallet would still detect outputs sending to the new address type
even without that address being requested from the wallet. Descriptor Wallets do not
allow for this and will only watch for the addresses that were explicitly requested from the wallet.

These changes to IsMine will make it easier to reason about what scripts the wallet will
actually be watching for in outputs. However for the vast majority of users, this change is
largely transparent and will not have noticeable effect.

Imports and Exports

In Legacy Wallets, raw scripts and keys could be imported to the wallet. Those imported scripts
and keys are treated separately from the keys generated by the wallet. This complicates the IsMine
logic as it has to distinguish between spendable and watchonly.

Descriptor Wallets handle importing scripts and keys differently. Only complete descriptors can be
imported. These descriptors are then added to the wallet as if it were a descriptor generated by
the wallet itself. This simplifies the IsMine logic so that it no longer has to distinguish
between spendable and watchonly. As such, the watchonly model for Descriptor Wallets is also
different and described in more detail in the next section.

To import into a Descriptor Wallet, a new importdescriptors RPC has been added that uses a syntax
similar to that of importmulti.

As Legacy Wallets and Descriptor Wallets use different mechanisms for storing and importing scripts and keys
the existing import RPCs have been disabled for descriptor wallets.
New export RPCs for Descriptor Wallets have not yet been added.

The following RPCs are disabled for Descriptor Wallets:

importprivkey
importpubkey
importaddress
importwallet
dumpprivkey
dumpwallet
importmulti
addmultisigaddress
sethdseed

Watchonly Wallets

A Legacy Wallet contains both private keys and scripts that were being watched.
Those watched scripts would not contribute to your normal balance. In order to see the watchonly
balance and to use watchonly things in transactions, an include_watchonly option was added
to many RPCs that would allow users to do that. However it is easy to forget to include this option.

Descriptor Wallets move to a per-wallet watchonly model. Instead an entire wallet is considered to be
watchonly depending on whether it was created with private keys disabled. This eliminates the need
to distinguish between things that are watchonly and things that are not within a wallet itself.

This change does have a caveat. If a Descriptor Wallet with private keys enabled has
a multiple key descriptor without all of the private keys (e.g. multi(...) with only one private key),
then the wallet will fail to sign and broadcast transactions. Such wallets would need to use the PSBT
workflow but the typical GUI Send, sendtoaddress, etc. workflows would still be available, just
non-functional.

This issue is worsened if the wallet contains both single key (e.g. wpkh(...)) descriptors and such
multiple key descriptors as some transactions could be signed and broadcast and others not. This is
due to some transactions containing only single key inputs, while others would contain both single
key and multiple key inputs, depending on which are available and how the coin selection algorithm
selects inputs. However this is not considered to be a supported use case; multisigs
should be in their own wallets which do not already have descriptors. Although users cannot export
descriptors with private keys for now as explained earlier.

BIP 44/49/84 Support

The change to using descriptors changes the default derivation paths used by Bitcoin Core
to adhere to BIP 44/49/84. Descriptors with different derivation paths can be imported without
issue.

SQLite Database Backend

Descriptor wallets use SQLite for the wallet file instead of the Berkeley DB used in legacy wallets.
This will break compatibility with any existing tooling that operates on wallets, however compatibility
was already being broken by the move to descriptors.

Wallet RPC changes

The upgradewallet RPC replaces the -upgradewallet command line option.
(#15761)
The settxfee RPC will fail if the fee was set higher than the -maxtxfee
command line setting. The wallet will already fail to create transactions
with fees higher than -maxtxfee. (#18467)
A new fee_rate parameter/option denominated in satoshis per vbyte (sat/vB)
is introduced to the sendtoaddress, sendmany, fundrawtransaction and
walletcreatefundedpsbt RPCs as well as to the experimental new send
RPC. The legacy feeRate option in fundrawtransaction and
walletcreatefundedpsbt still exists for setting a fee rate in BTC per 1,000
vbytes (BTC/kvB), but it is expected to be deprecated soon to avoid
confusion. For these RPCs, the fee rate error message is updated from BTC/kB
to sat/vB and the help documentation in BTC/kB is updated to BTC/kvB. The
send and sendtoaddress RPC examples are updated to aid users in creating
transactions with explicit fee rates. (#20305, #11413)
The bumpfee RPC fee_rate option is changed from BTC/kvB to sat/vB and the
help documentation is updated. Users are warned that this is a breaking API
change, but it should be relatively benign: the large (100,000 times)
difference between BTC/kvB and sat/vB units means that a transaction with a
fee rate mistakenly calculated in BTC/kvB rather than sat/vB should raise an
error due to the fee rate being set too low. In the worst case, the
transaction may send at 1 sat/vB, but as Replace-by-Fee (BIP125 RBF) is active
by default when an explicit fee rate is used, the transaction fee can be
bumped. (#20305)

GUI changes

Wallets created or loaded in the GUI will now be automatically loaded on
startup, so they don’t need to be manually reloaded next time Bitcoin Core is
started. The list of wallets to load on startup is stored in
<datadir>/settings.json and augments any command line or bitcoin.conf
-wallet= settings that specify more wallets to load. Wallets that are
unloaded in the GUI get removed from the settings list so they won’t load
again automatically next startup. (#19754)
The GUI Peers window no longer displays a “Ban Score” field. This is part of
changes in 0.20.1 and in this release to the handling of misbehaving
peers. Refer to “Changes regarding misbehaving peers” in the 0.20.1 release
notes for details. (#19512)

Low-level changes

RPC

To make RPC sendtoaddress more consistent with sendmany the following error
sendtoaddress codes were changed from -4 to -6:
- Insufficient funds
- Fee estimation failed
- Transaction has too long of a mempool chain
The sendrawtransaction error code for exceeding maxfeerate has been changed from
-26 to -25. The error string has been changed from “absurdly-high-fee” to
“Fee exceeds maximum configured by user (e.g. -maxtxfee, maxfeerate).” The
testmempoolaccept RPC returns max-fee-exceeded rather than absurdly-high-fee
as the reject-reason. (#19339)
To make wallet and rawtransaction RPCs more consistent, the error message for
exceeding maximum feerate has been changed to “Fee exceeds maximum configured by user
(e.g. -maxtxfee, maxfeerate).” (#19339)

Tests

The BIP 325 default signet can be enabled by the -chain=signet or -signet
setting. The settings -signetchallenge and -signetseednode allow
enabling a custom signet.
The generateblock RPC allows testers using regtest mode to
generate blocks that consist of a custom set of transactions. (#17693)

0.21.0 change log

Consensus

#18267 BIP-325: Signet (kallewoof)
#20016 uint256: 1 is a constant (ajtowns)
#20006 Fix misleading error message: Clean stack rule (sanket1729)
#19953 Implement BIP 340-342 validation (Schnorr/taproot/tapscript) (sipa)
#20169 Taproot follow-up: Make ComputeEntrySchnorr and ComputeEntryECDSA const to clarify contract (practicalswift)

Policy

#18766 Disable fee estimation in blocksonly mode (darosior)
#19630 Cleanup fee estimation code (darosior)
#20165 Only relay Taproot spends if next block has it active (sipa)

Mining

#17946 Fix GBT: Restore “!segwit” and “csv” to “rules” key (luke-jr)

Privacy

#16432 Add privacy to the Overview page (hebasto)
#18861 Do not answer GETDATA for to-be-announced tx (sipa)
#18038 Mempool tracks locally submitted transactions to improve wallet privacy (amitiuttarwar)
#19109 Only allow getdata of recently announced invs (sipa)

Block and transaction handling

#17737 Add ChainstateManager, remove BlockManager global (jamesob)
#18960 indexes: Add compact block filter headers cache (jnewbery)
#13204 Faster sigcache nonce (JeremyRubin)
#19088 Use std::chrono throughout some validation functions (fanquake)
#19142 Make VerifyDB level 4 interruptible (MarcoFalke)
#17994 Flush undo files after last block write (kallewoof)
#18990 log: Properly log txs rejected from mempool (MarcoFalke)
#18984 Remove unnecessary input blockfile SetPos (dgenr8)
#19526 log: Avoid treating remote misbehvior as local system error (MarcoFalke)
#18044 Use wtxid for transaction relay (sdaftuar)
#18637 coins: allow cache resize after init (jamesob)
#19854 Avoid locking CTxMemPool::cs recursively in simple cases (hebasto)
#19478 Remove CTxMempool::mapLinks data structure member (JeremyRubin)
#19927 Reduce direct g_chainman usage (dongcarl)
#19898 log: print unexpected version warning in validation log category (n-thumann)
#20036 signet: Add assumed values for default signet (MarcoFalke)
#20048 chainparams: do not log signet startup messages for other chains (jonatack)
#19339 re-delegate absurd fee checking from mempool to clients (glozow)
#20035 signet: Fix uninitialized read in validation (MarcoFalke)
#20157 Bugfix: chainparams: Add missing (always enabled) Taproot deployment for Signet (luke-jr)
#20263 Update assumed chain params (MarcoFalke)
#20372 Avoid signed integer overflow when loading a mempool.dat file with a malformed time field (practicalswift)
#18621 script: Disallow silent bool -> cscript conversion (MarcoFalke)
#18612, #18732 script: Remove undocumented and unused operator+ (MarcoFalke)
#19317 Add a left-justified width field to log2_work component for a uniform debug.log output (jamesgmorgan)

P2P protocol and network code

#18544 Limit BIP37 filter lifespan (active between filterload..filterclear) (theStack)
#18806 Remove is{Empty,Full} flags from CBloomFilter, clarify CVE fix (theStack)
#18512 Improve asmap checks and add sanity check (sipa)
#18877 Serve cfcheckpt requests (jnewbery)
#18895 Unbroadcast followups: rpcs, nLastResend, mempool sanity check (gzhao408)
#19010 net processing: Add support for getcfheaders (jnewbery)
#16939 Delay querying DNS seeds (ajtowns)
#18807 Unbroadcast follow-ups (amitiuttarwar)
#19044 Add support for getcfilters (jnewbery)
#19084 improve code documentation for dns seed behaviour (ajtowns)
#19260 disconnect peers that send filterclear + update existing filter msg disconnect logic (gzhao408)
#19284 Add seed.bitcoin.wiz.biz to DNS seeds (wiz)
#19322 split PushInventory() (jnewbery)
#19204 Reduce inv traffic during IBD (MarcoFalke)
#19470 banlist: log post-swept banlist size at startup (fanquake)
#19191 Extract download permission from noban (MarcoFalke)
#14033 Drop CADDR_TIME_VERSION checks now that MIN_PEER_PROTO_VERSION is greater (Empact)
#19464 net, rpc: remove -banscore option, deprecate banscore in getpeerinfo (jonatack)
#19514 [net/net processing] check banman pointer before dereferencing (jnewbery)
#19512 banscore updates to gui, tests, release notes (jonatack)
#19360 improve encapsulation of CNetAddr (vasild)
#19217 disambiguate block-relay-only variable names from blocksonly variables (glowang)
#19473 Add -networkactive option (hebasto)
#19472 [net processing] Reduce cs_main scope in MaybeDiscourageAndDisconnect() (jnewbery)
#19583 clean up Misbehaving() (jnewbery)
#19534 save the network type explicitly in CNetAddr (vasild)
#19569 Enable fetching of orphan parents from wtxid peers (sipa)
#18991 Cache responses to GETADDR to prevent topology leaks (naumenkogs)
#19596 Deduplicate parent txid loop of requested transactions and missing parents of orphan transactions (sdaftuar)
#19316 Cleanup logic around connection types (amitiuttarwar)
#19070 Signal support for compact block filters with NODE_COMPACT_FILTERS (jnewbery)
#19705 Shrink CAddress from 48 to 40 bytes on x64 (vasild)
#19704 Move ProcessMessage() to PeerLogicValidation (jnewbery)
#19628 Change CNetAddr::ip to have flexible size (vasild)
#19797 Remove old check for 3-byte shifted IP addresses from pre-0.2.9 nodes (#19797)
#19607 Add Peer struct for per-peer data in net processing (jnewbery)
#19857 improve nLastBlockTime and nLastTXTime documentation (jonatack)
#19724 Cleanup connection types- followups (amitiuttarwar)
#19670 Protect localhost and block-relay-only peers from eviction (sdaftuar)
#19728 Increase the ip address relay branching factor for unreachable networks (sipa)
#19879 Miscellaneous wtxid followups (amitiuttarwar)
#19697 Improvements on ADDR caching (naumenkogs)
#17785 Unify Send and Receive protocol versions (hebasto)
#19845 CNetAddr: add support to (un)serialize as ADDRv2 (vasild)
#19107 Move all header verification into the network layer, extend logging (troygiorshev)
#20003 Exit with error message if -proxy is specified without arguments (instead of continuing without proxy server) (practicalswift)
#19991 Use alternative port for incoming Tor connections (hebasto)
#19723 Ignore unknown messages before VERACK (sdaftuar)
#19954 Complete the BIP155 implementation and upgrade to TORv3 (vasild)
#20119 BIP155 follow-ups (sipa)
#19988 Overhaul transaction request logic (sipa)
#17428 Try to preserve outbound block-relay-only connections during restart (hebasto)
#19911 Guard vRecvGetData with cs_vRecv and orphan_work_set with g_cs_orphans (narula)
#19753 Don’t add AlreadyHave transactions to recentRejects (troygiorshev)
#20187 Test-before-evict bugfix and improvements for block-relay-only peers (sdaftuar)
#20237 Hardcoded seeds update for 0.21 (laanwj)
#20212 Fix output of peer address in version message (vasild)
#20284 Ensure old versions don’t parse peers.dat (vasild)
#20405 Avoid calculating onion address checksum when version is not 3 (lontivero)
#20564 Don’t send ‘sendaddrv2’ to pre-70016 software, and send before ‘verack’ (sipa)
#20660 Move signet onion seed from v2 to v3 (Sjors)

Wallet

#18262 Exit selection when best_waste is 0 (achow101)
#17824 Prefer full destination groups in coin selection (fjahr)
#17219 Allow transaction without change if keypool is empty (Sjors)
#15761 Replace -upgradewallet startup option with upgradewallet RPC (achow101)
#18671 Add BlockUntilSyncedToCurrentChain to dumpwallet (MarcoFalke)
#16528 Native Descriptor Wallets using DescriptorScriptPubKeyMan (achow101)
#18777 Recommend absolute path for dumpwallet (MarcoFalke)
#16426 Reverse cs_main, cs_wallet lock order and reduce cs_main locking (ariard)
#18699 Avoid translating RPC errors (MarcoFalke)
#18782 Make sure no DescriptorScriptPubKeyMan or WalletDescriptor members are left uninitialized after construction (practicalswift)
#9381 Remove CWalletTx merging logic from AddToWallet (ryanofsky)
#16946 Include a checksum of encrypted private keys (achow101)
#17681 Keep inactive seeds after sethdseed and derive keys from them as needed (achow101)
#18918 Move salvagewallet into wallettool (achow101)
#14988 Fix for confirmed column in csv export for payment to self transactions (benthecarman)
#18275 Error if an explicit fee rate was given but the needed fee rate differed (kallewoof)
#19054 Skip hdKeypath of ‘m’ when determining inactive hd seeds (achow101)
#17938 Disallow automatic conversion between disparate hash types (Empact)
#19237 Check size after unserializing a pubkey (elichai)
#11413 sendtoaddress/sendmany: Add explicit feerate option (kallewoof)
#18850 Fix ZapSelectTx to sync wallet spends (bvbfan)
#18923 Never schedule MaybeCompactWalletDB when -flushwallet is off (MarcoFalke)
#19441 walletdb: Don’t reinitialize desc cache with multiple cache entries (achow101)
#18907 walletdb: Don’t remove database transaction logs and instead error (achow101)
#19334 Introduce WalletDatabase abstract class (achow101)
#19335 Cleanup and separate BerkeleyDatabase and BerkeleyBatch (achow101)
#19102 Introduce and use DummyDatabase instead of dummy BerkeleyDatabase (achow101)
#19568 Wallet should not override signing errors (fjahr)
#17204 Do not turn OP_1NEGATE in scriptSig into 0x0181 in signing code (sipa) (meshcollider)
#19457 Cleanup wallettool salvage and walletdb extraneous declarations (achow101)
#15937 Add loadwallet and createwallet load_on_startup options (ryanofsky)
#16841 Replace GetScriptForWitness with GetScriptForDestination (meshcollider)
#14582 always do avoid partial spends if fees are within a specified range (kallewoof)
#19743 -maxapsfee follow-up (kallewoof)
#19289 GetWalletTx and IsMine require cs_wallet lock (promag)
#19671 Remove -zapwallettxes (achow101)
#19805 Avoid deserializing unused records when salvaging (achow101)
#19754 wallet, gui: Reload previously loaded wallets on startup (achow101)
#19738 Avoid multiple BerkeleyBatch in DelAddressBook (promag)
#19919 bugfix: make LoadWallet assigns status always (AkioNak)
#16378 The ultimate send RPC (Sjors)
#15454 Remove the automatic creation and loading of the default wallet (achow101)
#19501 send* RPCs in the wallet returns the “fee reason” (stackman27)
#20130 Remove db mode string (S3RK)
#19077 Add sqlite as an alternative wallet database and use it for new descriptor wallets (achow101)
#20125 Expose database format in getwalletinfo (promag)
#20198 Show name, format and if uses descriptors in bitcoin-wallet tool (jonasschnelli)
#20216 Fix buffer over-read in SQLite file magic check (theStack)
#20186 Make -wallet setting not create wallets (ryanofsky)
#20230 Fix bug when just created encrypted wallet cannot get address (hebasto)
#20282 Change upgradewallet return type to be an object (jnewbery)
#20220 Explicit fee rate follow-ups/fixes for 0.21 (jonatack)
#20199 Ignore (but warn) on duplicate -wallet parameters (jonasschnelli)
#20324 Set DatabaseStatus::SUCCESS in MakeSQLiteDatabase (MarcoFalke)
#20266 Fix change detection of imported internal descriptors (achow101)
#20153 Do not import a descriptor with hardened derivations into a watch-only wallet (S3RK)
#20344 Fix scanning progress calculation for single block range (theStack)
#19502 Bugfix: Wallet: Soft-fail exceptions within ListWalletDir file checks (luke-jr)
#20378 Fix potential division by 0 in WalletLogPrintf (jonasschnelli)
#18836 Upgradewallet fixes and additional tests (achow101)
#20139 Do not return warnings from UpgradeWallet() (stackman27)
#20305 Introduce fee_rate sat/vB param/option (jonatack)
#20426 Allow zero-fee fundrawtransaction/walletcreatefundedpsbt and other fixes (jonatack)
#20573 wallet, bugfix: allow send with string fee_rate amounts (jonatack)

RPC and other APIs

#18574 cli: Call getbalances.ismine.trusted instead of getwalletinfo.balance (jonatack)
#17693 Add generateblock to mine a custom set of transactions (andrewtoth)
#18495 Remove deprecated migration code (vasild)
#18493 Remove deprecated “size” from mempool txs (vasild)
#18467 Improve documentation and return value of settxfee (fjahr)
#18607 Fix named arguments in documentation (MarcoFalke)
#17831 doc: Fix and extend getblockstats examples (asoltys)
#18785 Prevent valgrind false positive in rest_blockhash_by_height (ryanofsky)
#18999 log: Remove “No rpcpassword set” from logs (MarcoFalke)
#19006 Avoid crash when g_thread_http was never started (MarcoFalke)
#18594 cli: Display multiwallet balances in -getinfo (jonatack)
#19056 Make gettxoutsetinfo/GetUTXOStats interruptible (MarcoFalke)
#19112 Remove special case for unknown service flags (MarcoFalke)
#18826 Expose txinwitness for coinbase in JSON form from RPC (rvagg)
#19282 Rephrase generatetoaddress help, and use PACKAGE_NAME (luke-jr)
#16377 don’t automatically append inputs in walletcreatefundedpsbt (Sjors)
#19200 Remove deprecated getaddressinfo fields (jonatack)
#19133 rpc, cli, test: add bitcoin-cli -generate command (jonatack)
#19469 Deprecate banscore field in getpeerinfo (jonatack)
#16525 Dump transaction version as an unsigned integer in RPC/TxToUniv (TheBlueMatt)
#19555 Deduplicate WriteHDKeypath() used in decodepsbt (theStack)
#19589 Avoid useless mempool query in gettxoutproof (MarcoFalke)
#19585 RPCResult Type of MempoolEntryDescription should be OBJ (stylesuxx)
#19634 Document getwalletinfo’s unlocked_until field as optional (justinmoon)
#19658 Allow RPC to fetch all addrman records and add records to addrman (jnewbery)
#19696 Fix addnode remove command error (fjahr)
#18654 Separate bumpfee’s psbt creation function into psbtbumpfee (achow101)
#19655 Catch listsinceblock target_confirmations exceeding block count (adaminsky)
#19644 Document returned error fields as optional if applicable (theStack)
#19455 rpc generate: print useful help and error message (jonatack)
#19550 Add listindices RPC (fjahr)
#19169 Validate provided keys for query_options parameter in listunspent (PastaPastaPasta)
#18244 fundrawtransaction and walletcreatefundedpsbt also lock manually selected coins (Sjors)
#14687 zmq: Enable TCP keepalive (mruddy)
#19405 Add network in/out connections to getnetworkinfo and -getinfo (jonatack)
#19878 rawtransaction: Fix argument in combinerawtransaction help message (pinheadmz)
#19940 Return fee and vsize from testmempoolaccept (gzhao408)
#13686 zmq: Small cleanups in the ZMQ code (domob1812)
#19386, #19528, #19717, #19849, #19994 Assert that RPCArg names are equal to CRPCCommand ones (MarcoFalke)
#19725 Add connection type to getpeerinfo, improve logs (amitiuttarwar)
#19969 Send RPC bug fix and touch-ups (Sjors)
#18309 zmq: Add support to listen on multiple interfaces (n-thumann)
#20055 Set HTTP Content-Type in bitcoin-cli (laanwj)
#19956 Improve invalid vout value rpc error message (n1rna)
#20101 Change no wallet loaded message to be clearer (achow101)
#19998 Add via_tor to getpeerinfo output (hebasto)
#19770 getpeerinfo: Deprecate “whitelisted” field (replaced by “permissions”) (luke-jr)
#20120 net, rpc, test, bugfix: update GetNetworkName, GetNetworksInfo, regression tests (jonatack)
#20595 Improve heuristic hex transaction decoding (sipa)
#20731 Add missing description of vout in getrawtransaction help text (benthecarman)
#19328 Add gettxoutsetinfo hash_type option (fjahr)
#19731 Expose nLastBlockTime/nLastTXTime as last block/last_transaction in getpeerinfo (jonatack)
#19572 zmq: Create “sequence” notifier, enabling client-side mempool tracking (instagibbs)
#20002 Expose peer network in getpeerinfo; simplify/improve -netinfo (jonatack)

GUI

#17905 Avoid redundant tx status updates (ryanofsky)
#18646 Use PACKAGE_NAME in exception message (fanquake)
#17509 Save and load PSBT (Sjors)
#18769 Remove bug fix for Qt < 5.5 (10xcryptodev)
#15768 Add close window shortcut (IPGlider)
#16224 Bilingual GUI error messages (hebasto)
#18922 Do not translate InitWarning messages in debug.log (hebasto)
#18152 Use NotificationStatus enum for signals to GUI (hebasto)
#18587 Avoid wallet tryGetBalances calls in WalletModel::pollBalanceChanged (ryanofsky)
#17597 Fix height of QR-less ReceiveRequestDialog (hebasto)
#17918 Hide non PKHash-Addresses in signing address book (emilengler)
#17956 Disable unavailable context menu items in transactions tab (kristapsk)
#17968 Ensure that ModalOverlay is resized properly (hebasto)
#17993 Balance/TxStatus polling update based on last block hash (furszy)
#18424 Use parent-child relation to manage lifetime of OptionsModel object (hebasto)
#18452 Fix shutdown when waitfor* cmds are called from RPC console (hebasto)
#15202 Add Close All Wallets action (promag)
#19132 lock cs_main, m_cached_tip_mutex in that order (vasild)
#18898 Display warnings as rich text (hebasto)
#19231 add missing translation.h include to fix build (fanquake)
#18027 “PSBT Operations” dialog (gwillen)
#19256 Change combiner for signals to optional_last_value (fanquake)
#18896 Reset toolbar after all wallets are closed (hebasto)
#18993 increase console command max length (10xcryptodev)
#19323 Fix regression in txoutset in GUI console (hebasto)
#19210 Get rid of cursor in out-of-focus labels (hebasto)
#19011 Reduce cs_main lock accumulation during GUI startup (jonasschnelli)
#19844 Remove usage of boost::bind (fanquake)
#20479 Fix QPainter non-determinism on macOS (0.21 backport) (laanwj)
gui#6 Do not truncate node flag strings in debugwindow peers details tab (Saibato)
gui#8 Fix regression in TransactionTableModel (hebasto)
gui#17 doc: Remove outdated comment in TransactionTablePriv (MarcoFalke)
gui#20 Wrap tooltips in the intro window (hebasto)
gui#30 Disable the main window toolbar when the modal overlay is shown (hebasto)
gui#34 Show permissions instead of whitelisted (laanwj)
gui#35 Parse params directly instead of through node (ryanofsky)
gui#39 Add visual accenting for the ‘Create new receiving address’ button (hebasto)
gui#40 Clarify block height label (hebasto)
gui#43 bugfix: Call setWalletActionsEnabled(true) only for the first wallet (hebasto)
gui#97 Relax GUI freezes during IBD (jonasschnelli)
gui#71 Fix visual quality of text in QR image (hebasto)
gui#96 Slight improve create wallet dialog (Sjors)
gui#102 Fix SplashScreen crash when run with -disablewallet (hebasto)
gui#116 Fix unreasonable default size of the main window without loaded wallets (hebasto)
gui#120 Fix multiwallet transaction notifications (promag)

Build system

#18504 Drop bitcoin-tx and bitcoin-wallet dependencies on libevent (ryanofsky)
#18586 Bump gitian descriptors to 0.21 (laanwj)
#17595 guix: Enable building for x86_64-w64-mingw32 target (dongcarl)
#17929 add linker optimisation flags to gitian & guix (Linux) (fanquake)
#18556 Drop make dist in gitian builds (hebasto)
#18088 ensure we aren’t using GNU extensions (fanquake)
#18741 guix: Make source tarball using git-archive (dongcarl)
#18843 warn on potentially uninitialized reads (vasild)
#17874 make linker checks more robust (fanquake)
#18535 remove -Qunused-arguments workaround for clang + ccache (fanquake)
#18743 Add –sysroot option to mac os native compile flags (ryanofsky)
#18216 test, build: Enable -Werror=sign-compare (Empact)
#18928 don’t pass -w when building for Windows (fanquake)
#16710 Enable -Wsuggest-override if available (hebasto)
#18738 Suppress -Wdeprecated-copy warnings (hebasto)
#18862 Remove fdelt_chk back-compat code and sanity check (fanquake)
#18887 enable -Werror=gnu (vasild)
#18956 enforce minimum required Windows version (7) (fanquake)
#18958 guix: Make V=1 more powerful for debugging (dongcarl)
#18677 Multiprocess build support (ryanofsky)
#19094 Only allow ASCII identifiers (laanwj)
#18820 Propagate well-known vars into depends (dongcarl)
#19173 turn on –enable-c++17 by –enable-fuzz (vasild)
#18297 Use pkg-config in BITCOIN_QT_CONFIGURE for all hosts including Windows (hebasto)
#19301 don’t warn when doxygen isn’t found (fanquake)
#19240 macOS toolchain simplification and bump (dongcarl)
#19356 Fix search for brew-installed BDB 4 on OS X (gwillen)
#19394 Remove unused RES_IMAGES (Bushstar)
#19403 improve __builtin_clz* detection (fanquake)
#19375 target Windows 7 when building libevent and fix ipv6 usage (fanquake)
#19331 Do not include server symbols in wallet (MarcoFalke)
#19257 remove BIP70 configure option (fanquake)
#18288 Add MemorySanitizer (MSan) in Travis to detect use of uninitialized memory (practicalswift)
#18307 Require pkg-config for all of the hosts (hebasto)
#19445 Update msvc build to use ISO standard C++17 (sipsorcery)
#18882 fix -Wformat-security check when compiling with GCC (fanquake)
#17919 Allow building with system clang (dongcarl)
#19553 pass -fcommon when building genisoimage (fanquake)
#19565 call AC_PATH_TOOL for dsymutil in macOS cross-compile (fanquake)
#19530 build LTO support into Apple’s ld64 (theuni)
#19525 add -Wl,-z,separate-code to hardening flags (fanquake)
#19667 set minimum required Boost to 1.58.0 (fanquake)
#19672 make clean removes .gcda and .gcno files from fuzz directory (Crypt-iQ)
#19622 Drop ancient hack in gitian-linux descriptor (hebasto)
#19688 Add support for llvm-cov (hebasto)
#19718 Add missed gcov files to ‘make clean’ (hebasto)
#19719 Add Werror=range-loop-analysis (MarcoFalke)
#19015 Enable some commonly enabled compiler diagnostics (practicalswift)
#19689 build, qt: Add Qt version checking (hebasto)
#17396 modest Android improvements (icota)
#18405 Drop all of the ZeroMQ patches (hebasto)
#15704 Move Win32 defines to configure.ac to ensure they are globally defined (luke-jr)
#19761 improve sed robustness by not using sed (fanquake)
#19758 Drop deprecated and unused GUARDED_VAR and PT_GUARDED_VAR annotations (hebasto)
#18921 add stack-clash and control-flow protection options to hardening flags (fanquake)
#19803 Bugfix: Define and use HAVE_FDATASYNC correctly outside LevelDB (luke-jr)
#19685 CMake invocation cleanup (dongcarl)
#19861 add /usr/local/ to LCOV_FILTER_PATTERN for macOS builds (Crypt-iQ)
#19916 allow user to specify DIR_FUZZ_SEED_CORPUS for cov_fuzz (Crypt-iQ)
#19944 Update secp256k1 subtree (including BIP340 support) (sipa)
#19558 Split pthread flags out of ldflags and dont use when building libconsensus (fanquake)
#19959 patch qt libpng to fix powerpc build (fanquake)
#19868 Fix target name (hebasto)
#19960 The vcpkg tool has introduced a proper way to use manifests (sipsorcery)
#20065 fuzz: Configure check for main function (MarcoFalke)
#18750 Optionally skip external warnings (vasild)
#20147 Update libsecp256k1 (endomorphism, test improvements) (sipa)
#20156 Make sqlite support optional (compile-time) (luke-jr)
#20318 Ensure source tarball has leading directory name (MarcoFalke)
#20447 Patch qt_intersect_spans to avoid non-deterministic behavior in LLVM 8 (achow101)
#20505 Avoid secp256k1.h include from system (dergoegge)
#20527 Do not ignore Homebrew’s SQLite on macOS (hebasto)
#20478 Don’t set BDB flags when configuring without (jonasschnelli)
#20563 Check that Homebrew’s berkeley-db4 package is actually installed (hebasto)
#19493 Fix clang build on Mac (bvbfan)

Tests and QA

#18593 Complete impl. of msg_merkleblock and wait_for_merkleblock (theStack)
#18609 Remove REJECT message code (hebasto)
#18584 Check that the version message does not leak the local address (MarcoFalke)
#18597 Extend wallet_dump test to cover comments (MarcoFalke)
#18596 Try once more when RPC connection fails on Windows (MarcoFalke)
#18451 shift coverage from getunconfirmedbalance to getbalances (jonatack)
#18631 appveyor: Disable functional tests for now (MarcoFalke)
#18628 Add various low-level p2p tests (MarcoFalke)
#18615 Avoid accessing free’d memory in validation_chainstatemanager_tests (MarcoFalke)
#18571 fuzz: Disable debug log file (MarcoFalke)
#18653 add coverage for bitcoin-cli -rpcwait (jonatack)
#18660 Verify findCommonAncestor always initializes outputs (ryanofsky)
#17669 Have coins simulation test also use CCoinsViewDB (jamesob)
#18662 Replace gArgs with local argsman in bench (MarcoFalke)
#18641 Create cached blocks not in the future (MarcoFalke)
#18682 fuzz: http_request workaround for libevent < 2.1.1 (theStack)
#18692 Bump timeout in wallet_import_rescan (MarcoFalke)
#18695 Replace boost::mutex with std::mutex (hebasto)
#18633 Properly raise FailedToStartError when rpc shutdown before warmup finished (MarcoFalke)
#18675 Don’t initialize PrecomputedTransactionData in txvalidationcache tests (jnewbery)
#18691 Add wait_for_cookie_credentials() to framework for rpcwait tests (jonatack)
#18672 Add further BIP37 size limit checks to p2p_filter.py (theStack)
#18721 Fix linter issue (hebasto)
#18384 More specific feature_segwit test error messages and fixing incorrect comments (gzhao408)
#18575 bench: Remove requirement that all benches use same testing setup (MarcoFalke)
#18690 Check object hashes in wait_for_getdata (robot-visions)
#18712 display command line options passed to send_cli() in debug log (jonatack)
#18745 Check submitblock return values (MarcoFalke)
#18756 Use wait_for_getdata() in p2p_compactblocks.py (theStack)
#18724 Add coverage for -rpcwallet cli option (jonatack)
#18754 bench: Add caddrman benchmarks (vasild)
#18585 Use zero-argument super() shortcut (Python 3.0+) (theStack)
#18688 fuzz: Run in parallel (MarcoFalke)
#18770 Remove raw-tx byte juggling in mempool_reorg (MarcoFalke)
#18805 Add missing sync_all to wallet_importdescriptors.py (achow101)
#18759 bench: Start nodes with -nodebuglogfile (MarcoFalke)
#18774 Added test for upgradewallet RPC (brakmic)
#18485 Add mempool_updatefromblock.py (hebasto)
#18727 Add CreateWalletFromFile test (ryanofsky)
#18726 Check misbehavior more independently in p2p_filter.py (robot-visions)
#18825 Fix message for ECC_InitSanityCheck test (fanquake)
#18576 Use unittest for test_framework unit testing (gzhao408)
#18828 Strip down previous releases boilerplate (MarcoFalke)
#18617 Add factor option to adjust test timeouts (brakmic)
#18855 feature_backwards_compatibility.py test downgrade after upgrade (achow101)
#18864 Add v0.16.3 backwards compatibility test, bump v0.19.0.1 to v0.19.1 (Sjors)
#18917 fuzz: Fix vector size problem in system fuzzer (brakmic)
#18901 fuzz: use std::optional for sep_pos_opt variable (brakmic)
#18888 Remove RPCOverloadWrapper boilerplate (MarcoFalke)
#18952 Avoid os-dependent path (fametrano)
#18938 Fill fuzzing coverage gaps for functions in consensus/validation.h, primitives/block.h and util/translation.h (practicalswift)
#18986 Add capability to disable RPC timeout in functional tests (rajarshimaitra)
#18530 Add test for -blocksonly and -whitelistforcerelay param interaction (glowang)
#19014 Replace TEST_PREVIOUS_RELEASES env var with test_framework option (MarcoFalke)
#19052 Don’t limit fuzzing inputs to 1 MB for afl-fuzz (now: ∞ ∀ fuzzers) (practicalswift)
#19060 Remove global wait_until from p2p_getdata (MarcoFalke)
#18926 Pass ArgsManager into getarg_tests (glowang)
#19110 Explain that a bug should be filed when the tests fail (MarcoFalke)
#18965 Implement base58_decode (10xcryptodev)
#16564 Always define the raii_event_tests test suite (candrews)
#19122 Add missing sync_blocks to wallet_hd (MarcoFalke)
#18875 fuzz: Stop nodes in process_message* fuzzers (MarcoFalke)
#18974 Check that invalid witness destinations can not be imported (MarcoFalke)
#18210 Type hints in Python tests (kiminuo)
#19159 Make valgrind.supp work on aarch64 (MarcoFalke)
#19082 Moved the CScriptNum asserts into the unit test in script.py (gillichu)
#19172 Do not swallow flake8 exit code (hebasto)
#19188 Avoid overwriting the NodeContext member of the testing setup [-Wshadow-field] (MarcoFalke)
#18890 disconnect_nodes should warn if nodes were already disconnected (robot-visions)
#19227 change blacklist to blocklist (TrentZ)
#19230 Move base58 to own module to break circular dependency (sipa)
#19083 msg_mempool, fRelay, and other bloomfilter tests (gzhao408)
#16756 Connection eviction logic tests (mzumsande)
#19177 Fix and clean p2p_invalid_messages functional tests (troygiorshev)
#19264 Don’t import asyncio to test magic bytes (jnewbery)
#19178 Make mininode_lock non-reentrant (jnewbery)
#19153 Mempool compatibility test (S3RK)
#18434 Add a test-security target and run it in CI (fanquake)
#19252 Wait for disconnect in disconnect_p2ps + bloomfilter test followups (gzhao408)
#19298 Add missing sync_blocks (MarcoFalke)
#19304 Check that message sends successfully when header is split across two buffers (troygiorshev)
#19208 move sync_blocks and sync_mempool functions to test_framework.py (ycshao)
#19198 Check that peers with forcerelay permission are not asked to feefilter (MarcoFalke)
#19351 add two edge case tests for CSubNet (vasild)
#19272 net, test: invalid p2p messages and test framework improvements (jonatack)
#19348 Bump linter versions (duncandean)
#19366 Provide main(…) function in fuzzer. Allow building uninstrumented harnesses with –enable-fuzz (practicalswift)
#19412 move TEST_RUNNER_EXTRA into native tsan setup (fanquake)
#19368 Improve functional tests compatibility with BSD/macOS (S3RK)
#19028 Set -logthreadnames in unit tests (MarcoFalke)
#18649 Add std::locale::global to list of locale dependent functions (practicalswift)
#19140 Avoid fuzzer-specific nullptr dereference in libevent when handling PROXY requests (practicalswift)
#19214 Auto-detect SHA256 implementation in benchmarks (sipa)
#19353 Fix mistakenly swapped “previous” and “current” lock orders (hebasto)
#19533 Remove unnecessary cs_mains in denialofservice_tests (jnewbery)
#19423 add functional test for txrelay during and after IBD (gzhao408)
#16878 Fix non-deterministic coverage of test DoS_mapOrphans (davereikher)
#19548 fuzz: add missing overrides to signature_checker (jonatack)
#19562 Fix fuzzer compilation on macOS (freenancial)
#19370 Static asserts for consistency of fee defaults (domob1812)
#19599 clean message_count and last_message (troygiorshev)
#19597 test decodepsbt fee calculation (count input value only once per UTXO) (theStack)
#18011 Replace current benchmarking framework with nanobench (martinus)
#19489 Fail wait_until early if connection is lost (MarcoFalke)
#19340 Preserve the LockData initial state if “potential deadlock detected” exception thrown (hebasto)
#19632 Catch decimal.InvalidOperation from TestNodeCLI#send_cli (Empact)
#19098 Remove duplicate NodeContext hacks (ryanofsky)
#19649 Restore test case for p2p transaction blinding (instagibbs)
#19657 Wait until is_connected in add_p2p_connection (MarcoFalke)
#19631 Wait for ‘cmpctblock’ in p2p_compactblocks when it is expected (Empact)
#19674 use throwaway _ variable for unused loop counters (theStack)
#19709 Fix ‘make cov’ with clang (hebasto)
#19564 p2p_feefilter improvements (logging, refactoring, speedup) (theStack)
#19756 add sync_all to fix race condition in wallet groups test (kallewoof)
#19727 Removing unused classes from p2p_leak.py (dhruv)
#19722 Add test for getblockheader verboseness (torhte)
#19659 Add a seed corpus generation option to the fuzzing test_runner (darosior)
#19775 Activate segwit in TestChain100Setup (MarcoFalke)
#19760 Remove confusing mininode terminology (jnewbery)
#19752 Update wait_until usage in tests not to use the one from utils (slmtpz)
#19839 Set appveyor VM version to previous Visual Studio 2019 release (sipsorcery)
#19830 Add tsan supp for leveldb::DBImpl::DeleteObsoleteFiles (MarcoFalke)
#19710 bench: Prevent thread oversubscription and decreases the variance of result values (hebasto)
#19842 Update the vcpkg checkout commit ID in appveyor config (sipsorcery)
#19507 Expand functional zmq transaction tests (instagibbs)
#19816 Rename wait until helper to wait_until_helper (MarcoFalke)
#19859 Fixes failing functional test by changing version (n-thumann)
#19887 Fix flaky wallet_basic test (fjahr)
#19897 Change FILE_CHAR_BLOCKLIST to FILE_CHARS_DISALLOWED (verretor)
#19800 Mockwallet (MarcoFalke)
#19922 Run rpc_txoutproof.py even with wallet disabled (MarcoFalke)
#19936 batch rpc with params (instagibbs)
#19971 create default wallet in extended tests (Sjors)
#19781 add parameterized constructor for msg_sendcmpct() (theStack)
#19963 Clarify blocksonly whitelistforcerelay test (t-bast)
#20022 Use explicit p2p objects where available (guggero)
#20028 Check that invalid peer traffic is accounted for (MarcoFalke)
#20004 Add signet witness commitment section parse tests (MarcoFalke)
#20034 Get rid of default wallet hacks (ryanofsky)
#20069 Mention commit id in scripted diff error (laanwj)
#19947 Cover change_type option of “walletcreatefundedpsbt” RPC (guggero)
#20126 p2p_leak_tx.py improvements (use MiniWallet, add p2p_lock acquires) (theStack)
#20129 Don’t export in6addr_loopback (vasild)
#20131 Remove unused nVersion=1 in p2p tests (MarcoFalke)
#20161 Minor Taproot follow-ups (sipa)
#19401 Use GBT to get block versions correct (luke-jr)
#20159 mining_getblocktemplate_longpoll.py improvements (use MiniWallet, add logging) (theStack)
#20039 Convert amounts from float to decimal (prayank23)
#20112 Speed up wallet_resendwallettransactions with mockscheduler RPC (MarcoFalke)
#20247 fuzz: Check for addrv1 compatibility before using addrv1 serializer. Fuzz addrv2 serialization (practicalswift)
#20167 Add test for -blockversion (MarcoFalke)
#19877 Clarify rpc_net & p2p_disconnect_ban functional tests (amitiuttarwar)
#20258 Remove getnettotals/getpeerinfo consistency test (jnewbery)
#20242 fuzz: Properly initialize PrecomputedTransactionData (MarcoFalke)
#20262 Skip –descriptor tests if sqlite is not compiled (achow101)
#18788 Update more tests to work with descriptor wallets (achow101)
#20289 fuzz: Check for addrv1 compatibility before using addrv1 serializer/deserializer on CService (practicalswift)
#20290 fuzz: Fix DecodeHexTx fuzzing harness issue (practicalswift)
#20245 Run script_assets_test even if built –with-libs=no (MarcoFalke)
#20300 fuzz: Add missing ECC_Start to descriptor_parse test (S3RK)
#20283 Only try witness deser when checking for witness deser failure (MarcoFalke)
#20303 fuzz: Assert expected DecodeHexTx behaviour when using legacy decoding (practicalswift)
#20316 Fix wallet_multiwallet test issue on Windows (MarcoFalke)
#20326 Fix ecdsa_verify in test framework (stepansnigirev)
#20328 cirrus: Skip tasks on the gui repo main branch (MarcoFalke)
#20355 fuzz: Check for addrv1 compatibility before using addrv1 serializer/deserializer on CSubNet (practicalswift)
#20332 Mock IBD in net_processing fuzzers (MarcoFalke)
#20218 Suppress epoll_ctl data race (MarcoFalke)
#20375 fuzz: Improve coverage for CPartialMerkleTree fuzzing harness (practicalswift)
#19669 contrib: Fixup valgrind suppressions file (MarcoFalke)
#18879 valgrind: remove outdated suppressions (fanquake)
#19226 Add BerkeleyDatabase tsan suppression (MarcoFalke)
#20379 Remove no longer needed UBSan suppression (float divide-by-zero in validation.cpp) (practicalswift)
#18190, #18736, #18744, #18775, #18783, #18867, #18994, #19065,
#19067, #19143, #19222, #19247, #19286, #19296, #19379, #19934,
#20188, #20395 Add fuzzing harnessses (practicalswift)
#18638 Use mockable time for ping/pong, add tests (MarcoFalke)
#19951 CNetAddr scoped ipv6 test coverage, rename scopeId to m_scope_id (jonatack)
#20027 Use mockable time everywhere in net_processing (sipa)
#19105 Add Muhash3072 implementation in Python (fjahr)
#18704, #18752, #18753, #18765, #18839, #18866, #18873, #19022,
#19023, #19429, #19552, #19778, #20176, #20179, #20214, #20292,
#20299, #20322 Fix intermittent test issues (MarcoFalke)
#20390 CI/Cirrus: Skip merge_base step for non-PRs (luke-jr)
#18634 ci: Add fuzzbuzz integration configuration file (practicalswift)
#18591 Add C++17 build to Travis (sipa)
#18581, #18667, #18798, #19495, #19519, #19538 CI improvements (hebasto)
#18683, #18705, #18735, #18778, #18799, #18829, #18912, #18929,
#19008, #19041, #19164, #19201, #19267, #19276, #19321, #19371,
#19427, #19730, #19746, #19881, #20294, #20339, #20368 CI improvements (MarcoFalke)
#20489, #20506 MSVC CI improvements (sipsorcery)

Miscellaneous

#18713 scripts: Add macho stack canary check to security-check.py (fanquake)
#18629 scripts: Add pe .reloc section check to security-check.py (fanquake)
#18437 util: Detect posix_fallocate() instead of assuming (vasild)
#18413 script: Prevent ub when computing abs value for num opcode serialize (pierreN)
#18443 lockedpool: avoid sensitive data in core files (FreeBSD) (vasild)
#18885 contrib: Move optimize-pngs.py script to the maintainer repo (MarcoFalke)
#18317 Serialization improvements step 6 (all except wallet/gui) (sipa)
#16127 More thread safety annotation coverage (ajtowns)
#19228 Update libsecp256k1 subtree (sipa)
#19277 util: Add assert identity function (MarcoFalke)
#19491 util: Make assert work with any value (MarcoFalke)
#19205 script: previous_release.sh rewritten in python (bliotti)
#15935 Add /settings.json persistent settings storage (ryanofsky)
#19439 script: Linter to check commit message formatting (Ghorbanian)
#19654 lint: Improve commit message linter in travis (fjahr)
#15382 util: Add runcommandparsejson (Sjors)
#19614 util: Use have_fdatasync to determine fdatasync() use (fanquake)
#19813 util, ci: Hard code previous release tarball checksums (hebasto)
#19841 Implement Keccak and SHA3_256 (sipa)
#19643 Add -netinfo peer connections dashboard (jonatack)
#15367 feature: Added ability for users to add a startup command (benthecarman)
#19984 log: Remove static log message “Initializing chainstate Chainstate [ibd] @ height -1 (null)” (practicalswift)
#20092 util: Do not use gargs global in argsmanager member functions (hebasto)
#20168 contrib: Fix gen_key_io_test_vectors.py imports (MarcoFalke)
#19624 Warn on unknown rw_settings (MarcoFalke)
#20257 Update secp256k1 subtree to latest master (sipa)
#20346 script: Modify security-check.py to use “==” instead of “is” for literal comparison (tylerchambers)
#18881 Prevent UB in DeleteLock() function (hebasto)
#19180, #19189, #19190, #19220, #19399 Replace RecursiveMutex with Mutex (hebasto)
#19347 Make cs_inventory nonrecursive (jnewbery)
#19773 Avoid recursive lock in IsTrusted (promag)
#18790 Improve thread naming (hebasto)
#20140 Restore compatibility with old CSubNet serialization (sipa)
#17775 DecodeHexTx: Try case where txn has inputs first (instagibbs)

Documentation

#18502 Update docs for getbalance (default minconf should be 0) (uzyn)
#18632 Fix macos comments in release-notes (MarcoFalke)
#18645 Update thread information in developer docs (jnewbery)
#18709 Note why we can’t use thread_local with glibc back compat (fanquake)
#18410 Improve commenting for coins.cpp|h (jnewbery)
#18157 fixing init.md documentation to not require rpcpassword (jkcd)
#18739 Document how to fuzz Bitcoin Core using Honggfuzz (practicalswift)
#18779 Better explain GNU ld’s dislike of ld64’s options (fanquake)
#18663 Mention build docs in README.md (saahilshangle)
#18810 Update rest info on block size and json (chrisabrams)
#18939 Add c++17-enable flag to fuzzing instructions (mzumsande)
#18957 Add a link from ZMQ doc to ZMQ example in contrib/ (meeDamian)
#19058 Drop protobuf stuff (hebasto)
#19061 Add link to Visual Studio build readme (maitrebitcoin)
#19072 Expand section on Getting Started (MarcoFalke)
#18968 noban precludes maxuploadtarget disconnects (MarcoFalke)
#19005 Add documentation for ‘checklevel’ argument in ‘verifychain’ RPC… (kcalvinalvin)
#19192 Extract net permissions doc (MarcoFalke)
#19071 Separate repository for the gui (MarcoFalke)
#19018 fixing description of the field sequence in walletcreatefundedpsbt RPC method (limpbrains)
#19367 Span pitfalls (sipa)
#19408 Windows WSL build recommendation to temporarily disable Win32 PE support (sipsorcery)
#19407 explain why passing -mlinker-version is required when cross-compiling (fanquake)
#19452 afl fuzzing comment about afl-gcc and afl-g++ (Crypt-iQ)
#19258 improve subtree check instructions (Sjors)
#19474 Use precise permission flags where possible (MarcoFalke)
#19494 CONTRIBUTING.md improvements (jonatack)
#19268 Add non-thread-safe note to FeeFilterRounder::round() (hebasto)
#19547 Update macOS cross compilation dependencies for Focal (hebasto)
#19617 Clang 8 or later is required with FORCE_USE_SYSTEM_CLANG (fanquake)
#19639 Remove Reference Links #19582 (RobertHosking)
#19605 Set CC_FOR_BUILD when building on OpenBSD (fanquake)
#19765 Fix getmempoolancestors RPC result doc (MarcoFalke)
#19786 Remove label from good first issue template (MarcoFalke)
#19646 Updated outdated help command for getblocktemplate (jakeleventhal)
#18817 Document differences in bitcoind and bitcoin-qt locale handling (practicalswift)
#19870 update PyZMQ install instructions, fix zmq_sub.py file permissions (jonatack)
#19903 Update build-openbsd.md with GUI support (grubles)
#19241 help: Generate checkpoint height from chainparams (luke-jr)
#18949 Add CODEOWNERS file to automatically nominate PR reviewers (adamjonas)
#20014 Mention signet in -help output (hebasto)
#20015 Added default signet config for linearize script (gr0kchain)
#19958 Better document features of feelers (naumenkogs)
#19871 Clarify scope of eviction protection of outbound block-relay peers (ariard)
#20076 Update and improve files.md (hebasto)
#20107 Collect release-notes snippets (MarcoFalke)
#20109 Release notes and followups from 19339 (glozow)
#20090 Tiny followups to new getpeerinfo connection type field (amitiuttarwar)
#20152 Update wallet files in files.md (hebasto)
#19124 Document ALLOW_HOST_PACKAGES dependency option (skmcontrib)
#20271 Document that wallet salvage is experimental (MarcoFalke)
#20281 Correct getblockstats documentation for (sw)total_weight (shesek)
#20279 release process updates/fixups (jonatack)
#20238 Missing comments for signet parameters (decryp2kanon)
#20756 Add missing field (permissions) to the getpeerinfo help (amitiuttarwar)
#20668 warn that incoming conns are unlikely when not using default ports (adamjonas)
#19961 tor.md updates (jonatack)
#19050 Add warning for rest interface limitation (fjahr)
#19390 doc/REST-interface: Remove stale info (luke-jr)
#19344 docs: update testgen usage example (Bushstar)

Credits

Thanks to everyone who directly contributed to this release:

10xcryptodev
Aaron Clauson
Aaron Hook
Adam Jonas
Adam Soltys
Adam Stein
Akio Nakamura
Alex Willmer
Amir Ghorbanian
Amiti Uttarwar
Andrew Chow
Andrew Toth
Anthony Fieroni
Anthony Towns
Antoine Poinsot
Antoine Riard
Ben Carman
Ben Woosley
Benoit Verret
Brian Liotti
Bushstar
Calvin Kim
Carl Dong
Chris Abrams
Chris L
Christopher Coverdale
codeShark149
Cory Fields
Craig Andrews
Damian Mee
Daniel Kraft
Danny Lee
David Reikher
DesWurstes
Dhruv Mehta
Duncan Dean
Elichai Turkel
Elliott Jin
Emil Engler
Ethan Heilman
eugene
Fabian Jahr
fanquake
Ferdinando M. Ametrano
freenancial
furszy
Gillian Chu
Gleb Naumenko
Glenn Willen
Gloria Zhao
glowang
gr0kchain
Gregory Sanders
grubles
gzhao408
Harris
Hennadii Stepanov
Hugo Nguyen
Igor Cota
Ivan Metlushko
Ivan Vershigora
Jake Leventhal
James O’Beirne
Jeremy Rubin
jgmorgan
Jim Posen
“jkcd”
jmorgan
John Newbery
Johnson Lau
Jon Atack
Jonas Schnelli
Jonathan Schoeller
João Barbosa
Justin Moon
kanon
Karl-Johan Alm
Kiminuo
Kristaps Kaupe
lontivero
Luke Dashjr
Marcin Jachymiak
MarcoFalke
Martin Ankerl
Martin Zumsande
maskoficarus
Matt Corallo
Matthew Zipkin
MeshCollider
Miguel Herranz
MIZUTA Takeshi
mruddy
Nadav Ivgi
Neha Narula
Nicolas Thumann
Niklas Gögge
Nima Yazdanmehr
nsa
nthumann
Oliver Gugger
pad
pasta
Peter Bushnell
pierrenn
Pieter Wuille
practicalswift
Prayank
Raúl Martínez (RME)
RandyMcMillan
Rene Pickhardt
Riccardo Masutti
Robert
Rod Vagg
Roy Shao
Russell Yanofsky
Saahil Shangle
sachinkm77
saibato
Samuel Dobson
sanket1729
Sebastian Falbesoner
Seleme Topuz
Sishir Giri
Sjors Provoost
skmcontrib
Stepan Snigirev
Stephan Oeste
Suhas Daftuar
t-bast
Tom Harding
Torhte Butler
TrentZ
Troy Giorshev
tryphe
Tyler Chambers
U-Zyn Chua
Vasil Dimov
wiz
Wladimir J. van der Laan

As well as to everyone that helped with translations on
Transifex.

0.21.0 Release Notes

How to Upgrade

Compatibility

Notable changes

P2P and network changes

Updated RPCs

New RPCs

Build System

Updated settings

Tools and Utilities

New settings

Wallet

Automatic wallet creation removed

Experimental Descriptor Wallets

Creating Descriptor Wallets

IsMine Semantics

Imports and Exports

Watchonly Wallets

BIP 44/49/84 Support

SQLite Database Backend

Wallet RPC changes

GUI changes

Low-level changes

RPC

Tests

0.21.0 change log

Consensus

Policy

Mining

Privacy

Block and transaction handling

P2P protocol and network code

Wallet

RPC and other APIs

GUI

Build system

Tests and QA

Miscellaneous

Documentation

Credits

`IsMine` Semantics