Bitcoin Core version 0.17.0 is now available from:
Changed configuration options
-includeconf=<file>can be used to include additional configuration files. Only works inside the
bitcoin.conffile, not inside included files or from command-line. Multiple files may be included. Can be disabled from command- line via
-noincludeconf. Note that multi-argument commands like
-includeconfwill override preceding
as bitcoin.conf will still include
- Block storage can be limited under Preferences, in the Main tab. Undoing this setting requires downloading the full blockchain again. This mode is incompatible with -txindex and -rescan.
External wallet files
-wallet=<path> option now accepts full paths instead of requiring wallets
to be located in the -walletdir directory.
Newly created wallet format
-wallet=<path> is specified with a path that does not exist, it will now
create a wallet directory at the specified location (containing a wallet.dat
data file, a db.log file, and database/log.?????????? files) instead of just
creating a data file at the path and storing log files in the parent
directory. This should make backing up wallets more straightforward than
before because the specified wallet path can just be directly archived without
having to look in the parent directory for transaction log files.
For backwards compatibility, wallet paths that are names of existing data files
-walletdir directory will continue to be accepted and interpreted the
same as before.
Dynamic loading and creation of wallets
Previously, wallets could only be loaded or created at startup, by specifying
-wallet parameters on the command line or in the bitcoin.conf file. It is now possible to load, create and unload wallets dynamically at runtime:
- Existing wallets can be loaded by calling the
loadwalletRPC. The wallet can be specified as file/directory basename (which must be located in the
walletdirdirectory), or as an absolute path to a file/directory.
- New wallets can be created (and loaded) by calling the
createwalletRPC. The provided name must not match a wallet file in the
walletdirdirectory or the name of a wallet that is currently loaded.
- Loaded wallets can be unloaded by calling the
This feature is currently only available through the RPC interface.
Partial spend avoidance
When an address is paid multiple times the coins from those separate payments can be spent separately which hurts privacy due to linking otherwise separate addresses. A new
-avoidpartialspends flag has been added (default=false). If enabled, the wallet will always spend existing UTXO to the same address together even if it results in higher fees. If someone were to send coins to an address after it was used, those coins will still be included in future coin selections.
Configuration sections for testnet and regtest
It is now possible for a single configuration file to set different options for different networks. This is done by using sections or by prefixing the option with the network, such as:
main.uacomment=bitcoin test.uacomment=bitcoin-testnet regtest.uacomment=regtest [main] mempoolsize=300 [test] mempoolsize=100 [regtest] mempoolsize=20
If the following options are not in a section, they will only apply to mainnet:
The options to choose a network (
testnet=) must be specified
outside of sections.
‘label’ and ‘account’ APIs for wallet
A new ‘label’ API has been introduced for the wallet. This is intended as a replacement for the deprecated ‘account’ API. The ‘account’ can continue to be used in V0.17 by starting bitcoind with the ‘-deprecatedrpc=accounts’ argument, and will be fully removed in V0.18.
The label RPC methods mirror the account functionality, with the following functional differences:
- Labels can be set on any address, not just receiving addresses. This functionality was previously only available through the GUI.
- Labels can be deleted by reassigning all addresses using the
- There isn’t support for sending transactions from a label, or for determining which label a transaction was sent from.
- Labels do not have a balance.
Here are the changes to RPC methods:
|Deprecated Method||New Method||Notes|
||n/a||There is no replacement for
||no change in behavior|
||Both methods return new
||Both methods now:
BIP 174 Partially Signed Bitcoin Transactions support
BIP 174 PSBT is an interchange format for Bitcoin transactions that are not fully signed yet, together with relevant metadata to help entities work towards signing it. It is intended to simplify workflows where multiple parties need to cooperate to produce a transaction. Examples include hardware wallets, multisig setups, and CoinJoin transactions.
Overall, the construction of a fully signed Bitcoin transaction goes through the following steps:
- A Creator proposes a particular transaction to be created. He constructs a PSBT that contains certain inputs and outputs, but no additional metadata.
- For each input, an Updater adds information about the UTXOs being spent by the transaction to the PSBT.
- A potentially other Updater adds information about the scripts and public keys involved in each of the inputs (and possibly outputs) of the PSBT.
- Signers inspect the transaction and its metadata to decide whether they agree with the transaction. They can use amount information from the UTXOs to assess the values and fees involved. If they agree, they produce a partial signature for the inputs for which they have relevant key(s).
- A Finalizer is run for each input to convert the partial signatures and
possibly script information into a final
- An Extractor produces a valid Bitcoin transaction (in network format) from a PSBT for which all inputs are finalized.
Generally, each of the above (excluding Creator and Extractor) will simply add more and more data to a particular PSBT. In a naive workflow, they all have to operate sequentially, passing the PSBT from one to the next, until the Extractor can convert it to a real transaction. In order to permit parallel operation, Combiners can be employed which merge metadata from different PSBTs for the same unsigned transaction.
The names above in bold are the names of the roles defined in BIP174. They’re useful in understanding the underlying steps, but in practice, software and hardware implementations will typically implement multiple roles simultaneously.
converttopsbt(Creator) is a utility RPC that converts an unsigned raw transaction to PSBT format. It ignores existing signatures.
createpsbt(Creator) is a utility RPC that takes a list of inputs and outputs and converts them to a PSBT with no additional information. It is equivalent to calling
walletcreatefundedpsbt(Creator, Updater) is a wallet RPC that creates a PSBT with the specified inputs and outputs, adds additional inputs and change to it to balance it out, and adds relevant metadata. In particular, for inputs that the wallet knows about (counting towards its normal or watch-only balance), UTXO information will be added. For outputs and inputs with UTXO information present, key and script information will be added which the wallet knows about. It is equivalent to running
createrawtransaction, followed by
walletprocesspsbt(Updater, Signer, Finalizer) is a wallet RPC that takes as input a PSBT, adds UTXO, key, and script data to inputs and outputs that miss it, and optionally signs inputs. Where possible it also finalizes the partial signatures.
finalizepsbt(Finalizer, Extractor) is a utility RPC that finalizes any partial signatures, and if all inputs are finalized, converts the result to a fully signed transaction which can be broadcast with
combinepsbt(Combiner) is a utility RPC that implements a Combiner. It can be used at any point in the workflow to merge information added to different versions of the same PSBT. In particular it is useful to combine the output of multiple Updaters or Signers.
decodepsbtis a diagnostic utility RPC which will show all information in a PSBT in human-readable form, as well as compute its eventual fee if known.
Upgrading non-HD wallets to HD wallets
Since Bitcoin Core 0.13.0, creating new BIP 32 Hierarchical Deterministic
wallets has been supported by Bitcoin Core but old non-HD wallets could not be
upgraded to HD. Now non-HD wallets can be upgraded to HD using the
-upgradewallet command line option. This upgrade will result in the all keys
in the keypool being marked as used and a new keypool generated. A new backup
must be made when this upgrade is performed.
-upgradewallet can be used to upgraded from a non-split HD
chain (all keys generated with
m/0'/0'/i') to a split HD chain (receiving
keys generated with
'm/0'/0'/i' and change keys generated with
m'/0'/1'/i'). When this upgrade occurs, all keys already in the keypool will
remain in the keypool to be used until all keys from before the upgrade are
exhausted. This is to avoid issues with backups and downgrades when some keys
may come from the change key keypool. Users can begin using the new split HD
chain keypools by using the
newkeypool RPC to mark all keys in the keypool as
used and begin using a new keypool generated from the split HD chain.
HD Master key rotation
A new RPC,
sethdseed, has been introduced which allows users to set a new HD
seed or set their own HD seed. This allows for a new HD seed to be used. A
new backup must be made when a new HD seed is set.
Low-level RPC changes
The new RPC
scantxoutsetcan be used to scan the UTXO set for entries that match certain output descriptors. Refer to the output descriptors reference documentation for more details. This call is similar to
listunspentbut does not use a wallet, meaning that the wallet can be disabled at compile or run time. This call is experimental, as such, is subject to changes or removal in future releases.
createrawtransactionRPC will now accept an array or dictionary (kept for compatibility) for the
outputsparameter. This means the order of transaction outputs can be specified by the client.
fundrawtransactionRPC will reject the previously deprecated
sendmanynow shuffles outputs to improve privacy, so any previously expected behavior with regards to output ordering can no longer be relied upon.
The new RPC
testmempoolacceptcan be used to test acceptance of a transaction to the mempool without adding it.
JSON transaction decomposition now includes a
weightfield which provides the transaction’s exact weight. This is included in REST /rest/tx/ and /rest/block/ endpoints when in json mode. This is also included in
feesfield introduced in
getmempoolentrywhen verbosity is set to
descendantdenominated in BTC. This new field deprecates previous fee fields, such as
The new RPC
getzmqnotificationsreturns information about active ZMQ notifications.
When bitcoin is not started with any
-wallet=<path>options, the name of the default wallet returned by
listwalletsRPCs is now the empty string
"wallet.dat". If bitcoin is started with any
-wallet=<path>options, there is no change in behavior, and the name of any wallet is just its
Passing an empty string (
"") as the
fundrawtransactionRPCs is now an error. Previously, this would fall back to using the default address type. It is still possible to pass null or leave the parameter unset to use the default address type.
Bare multisig outputs to our keys are no longer automatically treated as incoming payments. As this feature was only available for multisig outputs for which you had all private keys in your wallet, there was generally no use for them compared to single-key schemes. Furthermore, no address format for such outputs is defined, and wallet software can’t easily send to it. These outputs will no longer show up in
listunspent, or contribute to your balance, unless they are explicitly watched (using
importmultiwith hex script argument).
signrawtransaction*also still works for them.
getwalletinfoRPC method now returns an
hdseedidvalue, which is always the same as the incorrectly-named
hdmasterkeyidwill be removed in V0.18.
getaddressinfoRPC method now returns an
hdseedidvalue, which is always the same as the incorrectly-named
hdmasterkeyidwill be removed in V0.18.
Parts of the
validateaddressRPC method have been deprecated and moved to
getaddressinfo. Clients must transition to using
getaddressinfoto access this information before upgrading to v0.18. The following deprecated fields have moved to
getaddressinfoand will only be shown with
signrawtransactionis deprecated and will be fully removed in v0.18. To use
signrawtransactionin v0.17, restart bitcoind with
-deprecatedrpc=signrawtransaction. Projects should transition to using
signrawtransactionwithwalletbefore upgrading to v0.18.
Other API changes
inactivehdmasterproperty in the
dumpwalletoutput has been corrected to
The log timestamp format is now ISO 8601 (e.g. “2018-02-28T12:34:56Z”).
When running bitcoind with
-daemon, logging to stdout is now the default behavior. Setting
-printtoconsole=1no longer implicitly disables logging to debug.log. Instead, logging to file can be explicitly disabled by setting
Transaction index changes
The transaction index is now built separately from the main node procedure,
-txindex flag can be toggled without a full reindex. If bitcoind
is run with
-txindex on a node that is already partially or fully synced
without one, the transaction index will be built in the background and become
available once caught up. When switching from running
-txindex to running
without the flag, the transaction index database will not be deleted
automatically, meaning it could be turned back on at a later time without a full
Miner block size removed
-blockmaxsize option for miners to limit their blocks’ sizes was
deprecated in V0.15.1, and has now been removed. Miners should use the
-blockmaxweight option if they want to limit the weight of their blocks.
Support for Python 2 has been discontinued for all test files and tools.