[rpc] Add incremental relay fee to getnetworkinfo

src/rpc/net.cpp

@@ -10,6 +10,7 @@
 #include "net.h"
 #include "net_processing.h"
 #include "netbase.h"
+#include "policy/policy.h"
 #include "protocol.h"
 #include "sync.h"
 #include "timedata.h"
@@ -417,6 +418,7 @@ UniValue getnetworkinfo(const JSONRPCRequest& request)
             "  ,...\n"
             "  ],\n"
             "  \"relayfee\": x.xxxxxxxx,                (numeric) minimum relay fee for non-free transactions in " + CURRENCY_UNIT + "/kB\n"
+            "  \"incrementalfee\": x.xxxxxxxx,          (numeric) minimum fee increment for mempool limiting or BIP 125 replacement in " + CURRENCY_UNIT + "/kB\n"
             "  \"localaddresses\": [                    (array) list of local addresses\n"
             "  {\n"
             "    \"address\": \"xxxx\",                 (string) network address\n"
@@ -447,6 +449,7 @@ UniValue getnetworkinfo(const JSONRPCRequest& request)
     }
     obj.push_back(Pair("networks",      GetNetworksInfo()));
     obj.push_back(Pair("relayfee",      ValueFromAmount(::minRelayTxFee.GetFeePerK())));
+    obj.push_back(Pair("incrementalfee", ValueFromAmount(::incrementalRelayFee.GetFeePerK())));
     UniValue localAddresses(UniValue::VARR);
     {
         LOCK(cs_mapLocalHost);

src/wallet/rpcwallet.cpp

@@ -2652,8 +2652,8 @@ UniValue bumpfee(const JSONRPCRequest& request)
             "By default, the new fee will be calculated automatically using estimatefee.\n"
             "The user can specify a confirmation target for estimatefee.\n"
             "Alternatively, the user can specify totalFee, or use RPC setpaytxfee to set a higher fee rate.\n"
-            "At a minimum, the new fee rate must be high enough to pay a new relay fee over the original fee\n"
-            "to enter the node's mempool.\n"
+            "At a minimum, the new fee rate must be high enough to pay an additional new relay fee (incrementalfee\n"
+            "returned by getnetworkinfo) to enter the node's mempool.\n"
             "\nArguments:\n"
             "1. txid                  (string, required) The txid to be bumped\n"
             "2. options               (object, optional)\n"