Skip to main content

Mining with Bitcoin Knots

Bitcoin Knots is the node software powering Ocean, the decentralized mining pool co-founded by Luke Dashjr and backed by Jack Dorsey and Tether. This guide covers Knots-specific mining features and configuration.

Why Miners Choose Knots​

Ocean Mining Pool​

Ocean launched in 2023 with a mission to decentralize Bitcoin mining by giving miners control over their own block templates. Key facts:

  • Runs Bitcoin Knots as its node software
  • Filters inscriptions by default (configurable)
  • Backed by Jack Dorsey, Tether ($500M+ mining investment)
  • Headquarters in El Salvador (2024)

Dashjr's argument for filtering: "Spam-filtered blocks often have more fees anyway for some reason." The pool allows miners to construct their own templates, reducing reliance on centralized operators.

Block Template Control​

Unlike Bitcoin Core, Knots gives miners fine-grained control over what goes into their blocks:

FeatureCoreKnots
-blockmaxsizeRemovedRestored
-blockprioritysizeRemovedRestored
Per-call template paramsNoYes
Inscription filteringNoYes

Block Size Configuration​

Knots Defaults (Conservative)​

bitcoin.conf
# Knots defaults - smaller, healthier blocks
blockmaxsize=300000      # 300 KB (Core removed this option)
blockmaxweight=1200000   # 1.2 MWU

Maximum Revenue Settings​

bitcoin.conf
# Maximum block size for maximum fees
blockmaxweight=4000000   # 4 MWU (full blocks)
# Note: Remove blockmaxsize when using blockmaxweight
blockmaxsize vs blockmaxweight

blockmaxweight is the preferred option since SegWit. Setting blockmaxsize to anything other than maximum will reduce your income. If you want full blocks, use only blockmaxweight=4000000.

Reserved Space​

bitcoin.conf
# Reserve weight for coinbase transaction
blockreservedweight=8000

# Reserve space for high-priority/low-fee transactions
blockprioritysize=50000

getblocktemplate Enhancements​

Per-Call Parameters (Knots v27.1+)​

Knots allows overriding block limits on each getblocktemplate call:

bitcoin-cli getblocktemplate '{
  "rules": ["segwit"],
  "blockmaxsize": 750000,
  "blockmaxweight": 3000000,
  "minfeerate": 5
}'

Parameters:

  • blockmaxsize — Override configured block size limit
  • blockmaxweight — Override configured weight limit
  • minfeerate — Minimum fee rate (sat/vB) for inclusion
Performance

Setting per-call parameters disables template caching, which may reduce efficiency with multiple applications using getblocktemplate.

Skip Validity Test​

For advanced setups using BIP 23 template proposals:

bitcoin-cli getblocktemplate '{
  "rules": ["segwit"],
  "capabilities": ["proposal", "skip_validity_test"]
}'

This skips the internal validity check and disables caching. Only use if you plan to follow up with a template proposal call.

Transaction Filtering for Mining​

Filter Inscriptions​

bitcoin.conf
# Reject inscription/ordinal transactions from mempool
rejectparasites=1

# Limit OP_RETURN data size
datacarriersize=42

# Charge full weight for data (no SegWit discount abuse)
datacarriercost=1.0

Filter Tokens​

bitcoin.conf
# Reject BRC-20 and similar token transactions
rejecttokens=1

The Filtering Debate​

Critics argue filtering reduces miner income. Dashjr's response:

"Bitcoin works with the assumption that a majority of miners are honest, not malicious. Besides, spam-filtered blocks often have more fees anyway for some reason."

The choice is yours — Knots provides the options, you decide the policy.

Fee Configuration​

bitcoin.conf
# Minimum fee for relay (affects mempool)
minrelaytxfee=0.00001

# Minimum fee for block inclusion
blockmintxfee=0.00001

# Sigops limits
bytespersigop=20
bytespersigopstrict=20
maxtxlegacysigops=2500

Pool Backend Setup​

RPC Configuration​

bitcoin.conf
# Enable RPC server
server=1

# Authentication
rpcuser=miner
rpcpassword=SECURE_RANDOM_PASSWORD

# Allow pool server access
rpcbind=0.0.0.0
rpcallowip=192.168.1.0/24

# Increase connection limits for pool
rpcthreads=16
rpcworkqueue=64

Memory Optimization​

For pools that need fast block assembly:

bitcoin.conf
# Large mempool for more transaction selection
maxmempool=1000

# More database cache
dbcache=4096

# Keep entire UTXO set in memory (if RAM permits)
# Requires significant RAM but speeds up block creation

Mining-Specific RPC Commands​

CommandDescription
getblocktemplateGet block template (enhanced in Knots)
submitblockSubmit solved block
getmininginfoMining statistics
prioritisetransactionAdjust transaction priority
getblocklocationsBlock file locations (Knots)

Example Configurations​

Ocean-Style (Filtered)​

bitcoin.conf
# Ocean-style configuration
server=1
rejectparasites=1
rejecttokens=1
datacarriersize=42
datacarriercost=1.0
blockmaxweight=3996000
blockreservedweight=4000

Maximum Revenue (Unfiltered)​

bitcoin.conf
# Maximum revenue configuration
server=1
corepolicy=1
blockmaxweight=4000000
maxmempool=1000

Solo Mining (Testnet)​

bitcoin.conf
# Testnet solo mining
testnet=1
server=1
gen=1
# Generate test blocks
bitcoin-cli -testnet generatetoaddress 1 $(bitcoin-cli -testnet getnewaddress)

Performance Patches​

Knots includes mining performance optimizations:

  • mining_avoid_block_copy — Reduces memory copies during block assembly
  • gbt_rpc_options — Per-call template customization
  • mining_priority — Transaction priority support

See Also​