Configuration Options

Complete reference of configuration options, including Knots-specific additions.

Knots-Specific Options

These options are unique to Bitcoin Knots or have different defaults than Bitcoin Core.

Data Carrier & Transaction Filtering

Option	Type	Default	Description
-datacarrier	bool	1	Relay and mine data carrier (OP_RETURN) transactions
-datacarriersize	int	83	Maximum size in bytes of OP_RETURN data we relay and mine
-datacarriercost	decimal	1.0	Treat extra data as N vbytes per actual byte for weight calculation
-datacarrierfullcount	bool	1	Apply datacarriersize limit to all known datacarrier methods
-acceptnonstddatacarrier	bool	0	Relay non-OP_RETURN datacarrier injection transactions
-permitbaredatacarrier	bool	0	Relay transactions that only have data carrier outputs
-rejectparasites	bool	1	Refuse to relay CAT21 spam transactions
-rejecttokens	bool	0	Refuse to relay transactions involving non-bitcoin tokens

Script & Validation Policy

Option	Type	Default	Description
-acceptnonstdtxn	bool	0	Relay and mine non-standard transactions
-permitbarepubkey	bool	0	Relay transactions with bare pubkey outputs
-permitbaremultisig	bool	0	Relay transactions with bare multisig outputs
-permitephemeral	string	"anchor,-send,-dust"	Comma-separated ephemeral output options
-acceptunknownwitness	bool	1	Relay transactions to unknown witness versions
-maxscriptsize	int	1650	Maximum script size (including witness) in bytes
-bytespersigop	int	20	Equivalent bytes per sigop for relay/mining
-bytespersigopstrict	int	20	Minimum bytes per sigop we relay and mine

Dynamic Fee & Dust

Option	Type	Default	Description
-dustdynamic	string	"off"	Auto-adjust dust fee: target:<blocks> or mempool:<kvB>
-dustrelayfee	amount	0.00003	Fee rate to define dust threshold (BTC/kvB)
-minrelaytxfee	amount	0.00001	Minimum fee for relay (BTC/kvB)
-incrementalrelayfee	amount	0.00001	Fee increment for RBF replacement (BTC/kvB)

Maturity Requirements

Option	Type	Default	Description
-minrelaycoinblocks	int	0	Minimum "coin blocks" (satoshis × blocks) to relay
-minrelaymaturity	int	0	Minimum blocks inputs must mature before spending

Mempool Policy

Option	Type	Default	Description
-spkreuse	string	"allow"	Address reuse policy: "allow" or "conflict"
-mempoolreplacement	string	"fee,-optin"	RBF policy: "fee,optin" or "fee,-optin" (full RBF)
-mempoolfullrbf	bool	1	Accept RBF without signaling
-mempooltruc	string	"accept"	TRUC transaction handling: "reject", "accept", or "enforce"

Block Creation (Mining)

Option	Type	Default	Description
-blockmaxsize	int	300000	Maximum block size in bytes
-blockmaxweight	int	1200000	Maximum block weight
-blockmintxfee	amount	0.00001	Minimum fee rate for block inclusion (BTC/kvB)
-blockprioritysize	int	100000	Space for high-priority/low-fee transactions
-blockreservedweight	int	8000	Reserved weight for coinbase
-maxtxlegacysigops	int	2500	Maximum legacy sigops per transaction

Core Policy Mode

Option	Type	Default	Description
-corepolicy	bool	0	Use Bitcoin Core policy defaults instead of Knots

When -corepolicy=1 is set, multiple options change to match Core behavior:

• Allows non-standard datacarriers
• Enables bare pubkey/multisig
• Disables parasite rejection
• Sets datacarriercost to 0.25
• Increases block sizes/weights
• Enforces TRUC

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Standard Options

These options exist in both Core and Knots.

Network

Option	Type	Default	Description
-listen	bool	1	Accept incoming connections
-maxconnections	int	125	Maximum peer connections
-port	int	8333	Listen port
-bind	string	all	Bind to specific address
-proxy	string	-	SOCKS5 proxy (supports per-network syntax)
-onlynet	string	all	Restrict to networks: ipv4, ipv6, onion, i2p, cjdns
-upnp	bool	0	Enable UPnP port mapping
-natpmp	bool	1	Enable NAT-PMP (default on in Knots v29+)

RPC

Option	Type	Default	Description
-server	bool	0	Enable RPC server
-rpcuser	string	-	RPC username
-rpcpassword	string	-	RPC password
-rpcport	int	8332	RPC port
-rpcbind	string	127.0.0.1	RPC bind address
-rpcallowip	string	127.0.0.1	Allowed RPC source IPs

Performance

Option	Type	Default	Description
-dbcache	int	450	Database cache size (MB)
-par	int	auto	Script verification threads
-maxmempool	int	300	Maximum mempool size (MB)
-mempoolexpiry	int	336	Mempool transaction expiry (hours)

Pruning

Option	Type	Default	Description
-prune	int	0	Prune to N MB (0 = disabled)
-txindex	bool	0	Maintain full transaction index

Wallet

Option	Type	Default	Description
-disablewallet	bool	0	Disable wallet functionality
-walletdir	string	-	Wallet directory
-addresstype	string	bech32	Default address type
-changetype	string	-	Change address type

Debug

Option	Type	Default	Description
-debug	string	-	Debug categories (net, rpc, mempool, etc.)
-debuglogfile	string	-	Log file path
-printtoconsole	bool	0	Print to console
-logsourcelocations	bool	0	Include source locations in logs

Software Expiry (Knots v29+)

Option	Type	Default	Description
-softwareexpiry	bool	1	Enable expiry warnings (4-week warning, alerts at expiry)

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Example Configurations

Conservative (Knots Defaults)

bitcoin.conf

# Uses Knots defaults - filters parasites, conservative limits
server=1
listen=1

Match Bitcoin Core Behavior

bitcoin.conf

# Single flag to use Core defaults
corepolicy=1
server=1

Maximum Filtering

bitcoin.conf

# Strict filtering of non-monetary transactions
rejectparasites=1
rejecttokens=1
datacarriersize=42
permitbarepubkey=0
permitbaremultisig=0
acceptnonstddatacarrier=0

Miner Configuration

bitcoin.conf

# Mining-focused settings
blockmaxsize=750000
blockmaxweight=3000000
blockprioritysize=50000

Privacy-Focused

bitcoin.conf

# Enhanced privacy
proxy=127.0.0.1:9050
onlynet=onion
listen=0

Configuration File Location

Platform	Path
Linux	~/.bitcoin/bitcoin.conf
macOS	~/Library/Application Support/Bitcoin/bitcoin.conf
Windows	%APPDATA%\Bitcoin\bitcoin.conf

See Also

• Mempool Policies — Policy details
• Configuration Guide — Usage examples