-?

Print this help message and exit

-alertnotify=<cmd>

Execute command when a relevant alert is received or we see a really long fork (%s in cmd is replaced by message)

-assumevalid=<hex>

If this block is in the chain assume that it and its ancestors are valid and potentially skip their script verification (0 to verify all, default: 0000000000000000000f2adce67e49b0b6bdeb9de8b7c3d7e93b21e7fc1e819d, testnet: 000000000000056c49030c174179b52a928c870e6e8a822c75973b7970cfbd01)

-blockfilterindex=<type>

Maintain an index of compact filters by block (default: 0, values: basic). If <type> is not supplied or if <type> = 1, indexes for all known types are enabled.

-blocknotify=<cmd>

Execute command when the best block changes (%s in cmd is replaced by block hash)

-blockreconstructionextratxn=<n>

Extra transactions to keep in memory for compact block reconstructions (default: 100)

-blocksdir=<dir>

Specify directory to hold blocks subdirectory for *.dat files (default: <datadir>)

-blocksonly

Whether to reject transactions from network peers. Automatic broadcast and rebroadcast of any transactions from inbound peers is disabled, unless '-whitelistforcerelay' is '1', in which case whitelisted peers' transactions will be relayed. RPC transactions are not affected. (default: 0)

-conf=<file>

Specify configuration file. Relative paths will be prefixed by datadir location. (default: bitcoin.conf)

-daemon

Run in the background as a daemon and accept commands

-datadir=<dir>

Specify data directory

-dbcache=<n>

Maximum database cache size <n> MiB (4 to 16384, default: 450). In addition, unused mempool memory is shared for this cache (see -maxmempool).

-debuglogfile=<file>

Specify location of debug log file. Relative paths will be prefixed by a net-specific datadir location. (-nodebuglogfile to disable; default: debug.log)

-includeconf=<file>

Specify additional configuration file, relative to the -datadir path (only useable from configuration file, not command line)

-loadblock=<file>

Imports blocks from external file on startup

-maxmempool=<n>

Keep the transaction memory pool below <n> megabytes (default: 300)

-maxorphantx=<n>

Keep at most <n> unconnectable transactions in memory (default: 100)

-mempoolexpiry=<n>

Do not keep transactions in the mempool longer than <n> hours (default: 336)

-par=<n>

Set the number of script verification threads (-6 to 15, 0 = auto, <0 = leave that many cores free, default: 0)

-persistmempool

Whether to save the mempool on shutdown and load on restart (default: 1)

-pid=<file>

Specify pid file. Relative paths will be prefixed by a net-specific datadir location. (default: bitcoind.pid)

-prune=<n>

Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks, and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex and -rescan. Warning: Reverting this setting requires re-downloading the entire blockchain. (default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >=550 = automatically prune block files to stay under the specified target size in MiB)

-reindex

Rebuild chain state and block index from the blk*.dat files on disk

-reindex-chainstate

Rebuild chain state from the currently indexed blocks. When in pruning mode or if blocks on disk might be corrupted, use full -reindex instead.

-sysperms

Create new files with system default permissions, instead of umask 077 (only effective with disabled wallet functionality)

-txindex

Maintain a full transaction index, used by the getrawtransaction rpc call (default: 0)

-version

Print version and exit

Connection options:

-addnode=<ip>

Add a node to connect to and attempt to keep the connection open (see the `addnode` RPC command help for more info). This option can be specified multiple times to add multiple nodes.

-asmap=<file>

Specify asn mapping used for bucketing of the peers (default: ip_asn.map). Relative paths will be prefixed by the net-specific datadir location.

-banscore=<n>

Threshold for disconnecting and discouraging misbehaving peers (default: 100)

-bantime=<n>

Default duration (in seconds) of manually configured bans (default: 86400)

-bind=<addr>

Bind to given address and always listen on it. Use [host]:port notation for IPv6

-connect=<ip>

Connect only to the specified node; -noconnect disables automatic connections (the rules for this peer are the same as for -addnode). This option can be specified multiple times to connect to multiple nodes.

-discover

Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)

-dns

Allow DNS lookups for -addnode, -seednode and -connect (default: 1)

-dnsseed

Query for peer addresses via DNS lookup, if low on addresses (default: 1 unless -connect used)

-externalip=<ip>

Specify your own public address

-forcednsseed

Always query for peer addresses via DNS lookup (default: 0)

-listen

Accept connections from outside (default: 1 if no -proxy or -connect)

-listenonion

Automatically create Tor hidden service (default: 1)

-maxconnections=<n>

Maintain at most <n> connections to peers (default: 125)

-maxreceivebuffer=<n>

Maximum per-connection receive buffer, <n>*1000 bytes (default: 5000)

-maxsendbuffer=<n>

Maximum per-connection send buffer, <n>*1000 bytes (default: 1000)

-maxtimeadjustment

Maximum allowed median peer time offset adjustment. Local perspective of time may be influenced by peers forward or backward by this amount. (default: 4200 seconds)

-maxuploadtarget=<n>

Tries to keep outbound traffic under the given target (in MiB per 24h), 0 = no limit (default: 0)

-onion=<ip:port>

Use separate SOCKS5 proxy to reach peers via Tor hidden services, set -noonion to disable (default: -proxy)

-onlynet=<net>

Make outgoing connections only through network <net> (ipv4, ipv6 or onion). Incoming connections are not affected by this option. This option can be specified multiple times to allow multiple networks.

-peerbloomfilters

Support filtering of blocks and transaction with bloom filters (default: 0)

-permitbaremultisig

Relay non-P2SH multisig (default: 1)

-port=<port>

Listen for connections on <port> (default: 8333, testnet: 18333, regtest: 18444)

-proxy=<ip:port>

Connect through SOCKS5 proxy, set -noproxy to disable (default: disabled)

-proxyrandomize

Randomize credentials for every proxy connection. This enables Tor stream isolation (default: 1)

-seednode=<ip>

Connect to a node to retrieve peer addresses, and disconnect. This option can be specified multiple times to connect to multiple nodes.

-timeout=<n>

Specify connection timeout in milliseconds (minimum: 1, default: 5000)

-torcontrol=<ip>:<port>

Tor control port to use if onion listening enabled (default: 127.0.0.1:9051)

-torpassword=<pass>

Tor control port password (default: empty)

-upnp

Use UPnP to map the listening port (default: 0)

-whitebind=<[permissions@]addr>

Bind to given address and whitelist peers connecting to it. Use [host]:port notation for IPv6. Allowed permissions are bloomfilter (allow requesting BIP37 filtered blocks and transactions), noban (do not ban for misbehavior), forcerelay (relay transactions that are already in the mempool; implies relay), relay (relay even in -blocksonly mode), and mempool (allow requesting BIP35 mempool contents). Specify multiple permissions separated by commas (default: noban,mempool,relay). Can be specified multiple times.

-whitelist=<[permissions@]IP address or network>

Whitelist peers connecting from the given IP address (e.g. 1.2.3.4) or CIDR notated network(e.g. 1.2.3.0/24). Uses same permissions as -whitebind. Can be specified multiple times.

Wallet options:

-addresstype

What type of addresses to use ("legacy", "p2sh-segwit", or "bech32", default: "bech32")

-avoidpartialspends

Group outputs by address, selecting all or none, instead of selecting on a per-output basis. Privacy is improved as an address is only used once (unless someone sends to it after spending from it), but may result in slightly higher fees as suboptimal coin selection may result due to the added limitation (default: 0 (always enabled for wallets with "avoid_reuse" enabled))

-changetype

What type of change to use ("legacy", "p2sh-segwit", or "bech32"). Default is same as -addresstype, except when -addresstype=p2sh-segwit a native segwit output is used when sending to a native segwit address)

-disablewallet

Do not load the wallet and disable wallet RPC calls

-discardfee=<amt>

The fee rate (in BTC/kB) that indicates your tolerance for discarding change by adding it to the fee (default: 0.0001). Note: An output is discarded if it is dust at this rate, but we will always discard up to the dust relay fee and a discard fee above that is limited by the fee estimate for the longest target

-fallbackfee=<amt>

A fee rate (in BTC/kB) that will be used when fee estimation has insufficient data. 0 to entirely disable the fallbackfee feature. (default: 0.00)

-keypool=<n>

Set key pool size to <n> (default: 1000). Warning: Smaller sizes may increase the risk of losing funds when restoring from an old backup, if none of the addresses in the original keypool have been used.

-mintxfee=<amt>

Fees (in BTC/kB) smaller than this are considered zero fee for transaction creation (default: 0.00001)

-paytxfee=<amt>

Fee (in BTC/kB) to add to transactions you send (default: 0.00)

-rescan

Rescan the block chain for missing wallet transactions on startup

-salvagewallet

Attempt to recover private keys from a corrupt wallet on startup

-spendzeroconfchange

Spend unconfirmed change when sending transactions (default: 1)

-txconfirmtarget=<n>

If paytxfee is not set, include enough fee so transactions begin confirmation on average within n blocks (default: 6)

-upgradewallet

Upgrade wallet to latest format on startup

-wallet=<path>

Specify wallet database path. Can be specified multiple times to load multiple wallets. Path is interpreted relative to <walletdir> if it is not absolute, and will be created if it does not exist (as a directory containing a wallet.dat file and log files). For backwards compatibility this will also accept names of existing data files in <walletdir>.)

-walletbroadcast

Make the wallet broadcast transactions (default: 1)

-walletdir=<dir>

Specify directory to hold wallets (default: <datadir>/wallets if it exists, otherwise <datadir>)

-walletnotify=<cmd>

Execute command when a wallet transaction changes. %s in cmd is replaced by TxID and %w is replaced by wallet name. %w is not currently implemented on windows. On systems where %w is supported, it should NOT be quoted because this would break shell escaping used to invoke the command.

-walletrbf

Send transactions with full-RBF opt-in enabled (RPC only, default: 0)

-zapwallettxes=<mode>

Delete all wallet transactions and only recover those parts of the blockchain through -rescan on startup (1 = keep tx meta data e.g. payment request information, 2 = drop tx meta data)

ZeroMQ notification options:

-zmqpubhashblock=<address>

Enable publish hash block in <address>

-zmqpubhashblockhwm=<n>

Set publish hash block outbound message high water mark (default: 1000)

-zmqpubhashtx=<address>

Enable publish hash transaction in <address>

-zmqpubhashtxhwm=<n>

Set publish hash transaction outbound message high water mark (default: 1000)

-zmqpubrawblock=<address>

Enable publish raw block in <address>

-zmqpubrawblockhwm=<n>

Set publish raw block outbound message high water mark (default: 1000)

-zmqpubrawtx=<address>

Enable publish raw transaction in <address>

-zmqpubrawtxhwm=<n>

Set publish raw transaction outbound message high water mark (default: 1000)

Debugging/Testing options:

-debug=<category>

Output debugging information (default: -nodebug, supplying <category> is optional). If <category> is not supplied or if <category> = 1, output all debugging information. <category> can be: net, tor, mempool, http, bench, zmq, walletdb, rpc, estimatefee, addrman, selectcoins, reindex, cmpctblock, rand, prune, proxy, mempoolrej, libevent, coindb, qt, leveldb, validation.

-debugexclude=<category>

Exclude debugging information for a category. Can be used in conjunction with -debug=1 to output debug logs for all categories except one or more specified categories.

-help-debug

Print help message with debugging options and exit

-logips

Include IP addresses in debug output (default: 0)

-logthreadnames

Prepend debug output with name of the originating thread (only available on platforms supporting thread_local) (default: 0)

-logtimestamps

Prepend debug output with timestamp (default: 1)

-maxtxfee=<amt>

Maximum total fees (in BTC) to use in a single wallet transaction; setting this too low may abort large transactions (default: 0.10)

-printtoconsole

Send trace/debug info to console (default: 1 when no -daemon. To disable logging to file, set -nodebuglogfile)

-shrinkdebugfile

Shrink debug.log file on client startup (default: 1 when no -debug)

-uacomment=<cmt>

Append comment to the user agent string

Chain selection options:

-chain=<chain>

Use the chain <chain> (default: main). Allowed values: main, test, regtest

-testnet

Use the test chain. Equivalent to -chain=test.

Node relay options:

-bytespersigop

Equivalent bytes per sigop in transactions for relay and mining (default: 20)

-datacarrier

Relay and mine data carrier transactions (default: 1)

-datacarriersize

Maximum size of data in data carrier transactions we relay and mine (default: 83)

-minrelaytxfee=<amt>

Fees (in BTC/kB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: 0.00001)

-whitelistforcerelay

Add 'forcerelay' permission to whitelisted inbound peers with default permissions. This will relay transactions even if the transactions were already in the mempool. (default: 0)

-whitelistrelay

Add 'relay' permission to whitelisted inbound peers with default permissions. This will accept relayed transactions even when not relaying transactions (default: 1)

Block creation options:

-blockmaxweight=<n>

Set maximum BIP141 block weight (default: 3996000)

-blockmintxfee=<amt>

Set lowest fee rate (in BTC/kB) for transactions to be included in block creation. (default: 0.00001)

RPC server options:

-rest

Accept public REST requests (default: 0)

-rpcallowip=<ip>

Allow JSON-RPC connections from specified source. Valid for <ip> are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24). This option can be specified multiple times

-rpcauth=<userpw>

Username and HMAC-SHA-256 hashed password for JSON-RPC connections. The field <userpw> comes in the format: <USERNAME>:<SALT>$<HASH>. A canonical python script is included in share/rpcauth. The client then connects normally using the rpcuser=<USERNAME>/rpcpassword=<PASSWORD> pair of arguments. This option can be specified multiple times

-rpcbind=<addr>[:port]

Bind to given address to listen for JSON-RPC connections. Do not expose the RPC server to untrusted networks such as the public internet! This option is ignored unless -rpcallowip is also passed. Port is optional and overrides -rpcport. Use [host]:port notation for IPv6. This option can be specified multiple times (default: 127.0.0.1 and ::1 i.e., localhost)

-rpccookiefile=<loc>

Location of the auth cookie. Relative paths will be prefixed by a net-specific datadir location. (default: data dir)

-rpcpassword=<pw>

Password for JSON-RPC connections

-rpcport=<port>

Listen for JSON-RPC connections on <port> (default: 8332, testnet: 18332, regtest: 18443)

-rpcserialversion

Sets the serialization of raw transaction or block hex returned in non-verbose mode, non-segwit(0) or segwit(1) (default: 1)

-rpcthreads=<n>

Set the number of threads to service RPC calls (default: 4)

-rpcuser=<user>

Username for JSON-RPC connections

-rpcwhitelist=<whitelist>

Set a whitelist to filter incoming RPC calls for a specific user. The field <whitelist> comes in the format: <USERNAME>:<rpc 1>,<rpc 2>,...,<rpc n>. If multiple whitelists are set for a given user, they are set-intersected. See -rpcwhitelistdefault documentation for information on default whitelist behavior.

-rpcwhitelistdefault

Sets default behavior for rpc whitelisting. Unless rpcwhitelistdefault is set to 0, if any -rpcwhitelist is set, the rpc server acts as if all rpc users are subject to empty-unless-otherwise-specified whitelists. If rpcwhitelistdefault is set to 1 and no -rpcwhitelist is set, rpc server acts as if all rpc users are subject to empty whitelists.

-server

Accept command line and JSON-RPC commands

Please contribute if you find Bitcoin Core useful. Visit <https://bitcoincore.org/> for further information about the software. The source code is available from <https://github.com/bitcoin/bitcoin>.

This is experimental software. Distributed under the MIT software license, see the accompanying file COPYING or <https://opensource.org/licenses/MIT>