RBF Configuration Example

Complete example of configuring RBF (Replace-By-Fee) for different use cases.

Exchange Node Configuration

For exchanges that need to protect users from unexpected transaction replacements:

[rbf]
mode = "conservative"
min_fee_rate_multiplier = 2.0
min_fee_bump_satoshis = 5000
min_confirmations = 1
max_replacements_per_tx = 3
cooldown_seconds = 300

[mempool]
max_mempool_mb = 500
max_mempool_txs = 200000
min_relay_fee_rate = 2
eviction_strategy = "lowest_fee_rate"
max_ancestor_count = 25
max_descendant_count = 25
persist_mempool = true

Why This Configuration:

• Conservative RBF: Requires 2x fee increase, preventing low-fee replacements
• 1 Confirmation Required: Additional safety check before allowing replacement
• Higher Fee Threshold: 2 sat/vB minimum relay fee filters low-priority transactions
• Mempool Persistence: Survives restarts for better reliability

Mining Pool Configuration

For mining pools that want to maximize fee revenue:

[rbf]
mode = "aggressive"
min_fee_rate_multiplier = 1.05
min_fee_bump_satoshis = 500
allow_package_replacements = true
max_replacements_per_tx = 10
cooldown_seconds = 60

[mempool]
max_mempool_mb = 1000
max_mempool_txs = 500000
min_relay_fee_rate = 1
eviction_strategy = "lowest_fee_rate"
max_ancestor_count = 50
max_descendant_count = 50

Why This Configuration:

• Aggressive RBF: Only 5% fee increase required, maximizing fee opportunities
• Package Replacements: Allows parent+child transaction replacements
• Larger Mempool: 1GB capacity for more transaction opportunities
• Relaxed Ancestor Limits: 50 transactions for larger packages

Standard Node Configuration

For general-purpose nodes with Bitcoin Core compatibility:

[rbf]
mode = "standard"
min_fee_rate_multiplier = 1.1
min_fee_bump_satoshis = 1000

[mempool]
max_mempool_mb = 300
max_mempool_txs = 100000
min_relay_fee_rate = 1
eviction_strategy = "lowest_fee_rate"
max_ancestor_count = 25
max_descendant_count = 25
mempool_expiry_hours = 336

Why This Configuration:

• Standard RBF: BIP125-compliant with 10% fee increase
• Bitcoin Core Defaults: Matches Bitcoin Core mempool settings
• Balanced: Good for most use cases

Testing RBF Configuration

Test Transaction Replacement

1. Create initial transaction:

# Send transaction with RBF signaling (sequence < 0xffffffff)
bitcoin-cli sendtoaddress <address> 0.001 "" "" true

2. Replace with higher fee:

# Create replacement with higher fee
bitcoin-cli bumpfee <txid> --fee_rate 20

3. Verify replacement:

# Check mempool
curl -X POST http://localhost:8332 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "method": "getmempoolentry", "params": ["<new_txid>"], "id": 1}'

Monitor RBF Activity

# Get mempool info
curl -X POST http://localhost:8332 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "method": "getmempoolinfo", "params": [], "id": 1}'

Expected Response:

{
  "jsonrpc": "2.0",
  "result": {
    "size": 1234,
    "bytes": 567890,
    "usage": 1234567,
    "maxmempool": 314572800,
    "mempoolminfee": 0.00001,
    "minrelaytxfee": 0.00001
  },
  "id": 1
}

See Also

• RBF and Mempool Policies - Complete configuration guide
• Node Configuration - All configuration options
• Node Operations - Managing your node