diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index b8592153a60bfc..32eb6b6f19c8dc 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -288,7 +288,7 @@ static RPCHelpMan waitfornewblock()
         "\nWaits for a specific new block and returns useful info about it.\n"
         "\nReturns the current block on timeout or exit.\n",
         {
-            {"timeout", RPCArg::Type::NUM, /* default */ "0", "Time in milliseconds to wait for a response. 0 indicates no timeout."},
+            {"timeout", RPCArg::Type::NUM, RPCArg::Default{0}, "Time in milliseconds to wait for a response. 0 indicates no timeout."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -331,7 +331,7 @@ static RPCHelpMan waitforblock()
         "\nReturns the current block on timeout or exit.\n",
         {
             {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "Block hash to wait for."},
-            {"timeout", RPCArg::Type::NUM, /* default */ "0", "Time in milliseconds to wait for a response. 0 indicates no timeout."},
+            {"timeout", RPCArg::Type::NUM, RPCArg::Default{0}, "Time in milliseconds to wait for a response. 0 indicates no timeout."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -378,7 +378,7 @@ static RPCHelpMan waitforblockheight()
         "\nReturns the current block on timeout or exit.\n",
         {
             {"height", RPCArg::Type::NUM, RPCArg::Optional::NO, "Block height to wait for."},
-            {"timeout", RPCArg::Type::NUM, /* default */ "0", "Time in milliseconds to wait for a response. 0 indicates no timeout."},
+            {"timeout", RPCArg::Type::NUM, RPCArg::Default{0}, "Time in milliseconds to wait for a response. 0 indicates no timeout."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -571,6 +571,7 @@ UniValue MempoolToJSON(const CTxMemPool& pool, llmq::CInstantSendManager* isman,
             return o;
         }
     }
+
 }
 
 static RPCHelpMan getrawmempool()
@@ -579,8 +580,8 @@ static RPCHelpMan getrawmempool()
         "\nReturns all transaction ids in memory pool as a json array of string transaction ids.\n"
         "\nHint: use getmempoolentry to fetch a specific transaction from the mempool.\n",
         {
-            {"verbose", RPCArg::Type::BOOL, /* default */ "false", "True for a json object, false for array of transaction ids"},
-            {"mempool_sequence", RPCArg::Type::BOOL, /* default */ "false", "If verbose=false, returns a json object with transaction list and mempool sequence number attached."},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "True for a json object, false for array of transaction ids"},
+            {"mempool_sequence", RPCArg::Type::BOOL, RPCArg::Default{false}, "If verbose=false, returns a json object with transaction list and mempool sequence number attached."},
         },
         {
             RPCResult{"for verbose = false",
@@ -632,7 +633,7 @@ static RPCHelpMan getmempoolancestors()
         "\nIf txid is in the mempool, returns all in-mempool ancestors.\n",
         {
             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id (must be in mempool)"},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "false", "True for a json object, false for array of transaction ids"},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "True for a json object, false for array of transaction ids"},
         },
         {
             RPCResult{"for verbose = false",
@@ -699,7 +700,7 @@ static RPCHelpMan getmempooldescendants()
         "\nIf txid is in the mempool, returns all in-mempool descendants.\n",
         {
             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id (must be in mempool)"},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "false", "True for a json object, false for array of transaction ids"},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "True for a json object, false for array of transaction ids"},
         },
         {
             RPCResult{"for verbose = false",
@@ -922,7 +923,7 @@ static RPCHelpMan getblockheader()
         "If verbose is true, returns an Object with information about blockheader <hash>.\n",
         {
             {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "true", "true for a json object, false for the hex-encoded data"},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{true}, "true for a json object, false for the hex-encoded data"},
         },
         {
             RPCResult{"for verbose = true",
@@ -996,8 +997,8 @@ static RPCHelpMan getblockheaders()
         "If verbose is true, each item is an Object with information about a single blockheader.\n",
         {
             {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
-            {"count", RPCArg::Type::NUM, /* default */ strprintf("%s", MAX_HEADERS_RESULTS), ""},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "true", "true for a json object, false for the hex-encoded data"},
+            {"count", RPCArg::Type::NUM, RPCArg::DefaultHint{strprintf("%s", MAX_HEADERS_RESULTS)}, ""},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{true}, "true for a json object, false for the hex-encoded data"},
         },
         {
             RPCResult{"for verbose = true",
@@ -1134,7 +1135,7 @@ static RPCHelpMan getmerkleblocks()
         {
             {"filter", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex-encoded bloom filter"},
             {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
-            {"count", RPCArg::Type::NUM, /* default */ strprintf("%s", MAX_HEADERS_RESULTS), ""},
+            {"count", RPCArg::Type::NUM, RPCArg::DefaultHint{strprintf("%s", MAX_HEADERS_RESULTS), ""},
         },
         RPCResult{
                 RPCResult::Type::ARR, "", "",
@@ -1210,7 +1211,7 @@ static RPCHelpMan getblock()
                 "If verbosity is 2, returns an Object with information about block <hash> and information about each transaction. \n",
                 {
                     {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
-                    {"verbosity|verbose", RPCArg::Type::NUM, /* default */ "1", "0 for hex-encoded data, 1 for a json object, and 2 for json object with transaction data"},
+                    {"verbosity|verbose", RPCArg::Type::NUM, RPCArg::Default{1}, "0 for hex-encoded data, 1 for a json object, and 2 for json object with transaction data"},
                 },
                 {
                     RPCResult{"for verbosity = 0",
@@ -1387,9 +1388,9 @@ static RPCHelpMan gettxoutsetinfo()
         "\nReturns statistics about the unspent transaction output set.\n"
         "Note this call may take some time if you are not using coinstatsindex.\n",
         {
-            {"hash_type", RPCArg::Type::STR, /* default */ "hash_serialized_2", "Which UTXO set hash should be calculated. Options: 'hash_serialized_2' (the legacy algorithm), 'muhash', 'none'."},
+            {"hash_type", RPCArg::Type::STR, RPCArg::Default{"hash_serialized_2"}, "Which UTXO set hash should be calculated. Options: 'hash_serialized_2' (the legacy algorithm), 'muhash', 'none'."},
             {"hash_or_height", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "The block hash or height of the target height (only available with coinstatsindex).", "", {"", "string or numeric"}},
-            {"use_index", RPCArg::Type::BOOL, /* default */ "true", "Use coinstatsindex, if available."},
+            {"use_index", RPCArg::Type::BOOL, RPCArg::Default{true}, "Use coinstatsindex, if available."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -1419,7 +1420,7 @@ static RPCHelpMan gettxoutsetinfo()
                     }}
                 }},
             }},
-        RPCExamples{
+        RPCExamples{                        
                 HelpExampleCli("gettxoutsetinfo", "") +
                 HelpExampleCli("gettxoutsetinfo", R"("none")") +
                 HelpExampleCli("gettxoutsetinfo", R"("none" 1000)") +
@@ -1531,7 +1532,7 @@ static RPCHelpMan gettxout()
         {
             {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
             {"n", RPCArg::Type::NUM, RPCArg::Optional::NO, "vout number"},
-            {"include_mempool", RPCArg::Type::BOOL, /* default */ "true", "Whether to include the mempool. Note that an unspent output that is spent in the mempool won't appear."},
+            {"include_mempool", RPCArg::Type::BOOL, RPCArg::Default{true}, "Whether to include the mempool. Note that an unspent output that is spent in the mempool won't appear."},
         },
         {
             RPCResult{"If the UTXO was not found", RPCResult::Type::NONE, "", ""},
@@ -1618,9 +1619,9 @@ static RPCHelpMan verifychain()
     return RPCHelpMan{"verifychain",
         "\nVerifies blockchain database.\n",
         {
-            {"checklevel", RPCArg::Type::NUM, /* default */ strprintf("%d, range=0-4", DEFAULT_CHECKLEVEL),
+            {"checklevel", RPCArg::Type::NUM, RPCArg::DefaultHint{strprintf("%d, range=0-4", DEFAULT_CHECKLEVEL),
                         strprintf("How thorough the block verification is:\n - %s", Join(CHECKLEVEL_DOC, "\n- "))},
-            {"nblocks", RPCArg::Type::NUM, /* default */ strprintf("%d, 0=all", DEFAULT_CHECKBLOCKS), "The number of blocks to check."},
+            {"nblocks", RPCArg::Type::NUM, RPCArg::DefaultHint{strprintf("%d, 0=all", DEFAULT_CHECKBLOCKS), "The number of blocks to check."},
         },
         RPCResult{
             RPCResult::Type::BOOL, "", "Verified or not"},
@@ -2170,8 +2171,8 @@ static RPCHelpMan getchaintxstats()
     return RPCHelpMan{"getchaintxstats",
                 "\nCompute statistics about the total number and rate of transactions in the chain.\n",
                 {
-                    {"nblocks", RPCArg::Type::NUM, /* default */ "one month", "Size of the window in number of blocks"},
-                    {"blockhash", RPCArg::Type::STR_HEX, /* default */ "chain tip", "The hash of the block that ends the window."},
+                    {"nblocks", RPCArg::Type::NUM, RPCArg::DefaultHint{"one month"}, "Size of the window in number of blocks"},
+                    {"blockhash", RPCArg::Type::STR_HEX, RPCArg::DefaultHint{"chain tip"}, "The hash of the block that ends the window."},
                 },
                 RPCResult{
                     RPCResult::Type::OBJ, "", "",
@@ -2320,7 +2321,7 @@ static RPCHelpMan getblockstats()
                 "It won't work for some heights with pruning.\n",
                 {
                     {"hash_or_height", RPCArg::Type::NUM, RPCArg::Optional::NO, "The block hash or height of the target block", "", {"", "string or numeric"}},
-                    {"stats", RPCArg::Type::ARR, /* default */ "all values", "Values to plot (see result below)",
+                    {"stats", RPCArg::Type::ARR, RPCArg::DefaultHint{"all values"}, "Values to plot (see result below)",
                         {
                             {"height", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Selected statistic"},
                             {"time", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Selected statistic"},
@@ -2540,8 +2541,8 @@ static RPCHelpMan getspecialtxes()
             {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
             {"type", RPCArg::Type::NUM, /* default */ "-1", "Filter special txes by type, -1 means all types"},
             {"count", RPCArg::Type::NUM, /* default */ "10", "The number of transactions to return"},
-            {"skip", RPCArg::Type::NUM, /* default */ "0", "The number of transactions to skip"},
-            {"verbosity", RPCArg::Type::NUM, /* default */ "0", "0 for hashes, 1 for hex-encoded data, and 2 for json object"},
+            {"skip", RPCArg::Type::NUM, RPCArg::Default{0}, "The number of transactions to skip"},
+            {"verbosity", RPCArg::Type::NUM, RPCArg::Default{0}, "0 for hashes, 1 for hex-encoded data, and 2 for json object"},
         },
         {
             RPCResult{"for verbosity = 0",
@@ -2755,7 +2756,7 @@ static RPCHelpMan scantxoutset()
                     {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "An object with output descriptor and metadata",
                         {
                             {"desc", RPCArg::Type::STR, RPCArg::Optional::NO, "An output descriptor"},
-                            {"range", RPCArg::Type::RANGE, /* default */ "1000", "The range of HD chain indexes to explore (either end or [begin,end])"},
+                            {"range", RPCArg::Type::RANGE, RPCArg::Default{1000}, "The range of HD chain indexes to explore (either end or [begin,end])"},
                         },
                     },
                 },
@@ -2901,7 +2902,7 @@ static RPCHelpMan getblockfilter()
         "\nRetrieve a BIP 157 content filter for a particular block.\n",
         {
             {"blockhash", RPCArg::Type::STR, RPCArg::Optional::NO, "The hash of the block"},
-            {"filtertype", RPCArg::Type::STR, /* default */ "basic", "The type name of the filter"},
+            {"filtertype", RPCArg::Type::STR, RPCArg::Default{"basic"}, "The type name of the filter"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 50956048dab137..9e956ce9122970 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -102,8 +102,8 @@ static RPCHelpMan getnetworkhashps()
         "Pass in [blocks] to override # of blocks, -1 specifies since last difficulty change.\n"
         "Pass in [height] to estimate the network speed at the time when a certain block was found.\n",
         {
-            {"nblocks", RPCArg::Type::NUM, /* default */ "120", "The number of blocks, or -1 for blocks since last difficulty change."},
-            {"height", RPCArg::Type::NUM, /* default */ "-1", "To estimate at the time of the given height."},
+            {"nblocks", RPCArg::Type::NUM, RPCArg::Default{120}, "The number of blocks, or -1 for blocks since last difficulty change."},
+            {"height", RPCArg::Type::NUM, RPCArg::Default{-1}, "To estimate at the time of the given height."},
         },
         RPCResult{
             RPCResult::Type::NUM, "", "Hashes per second estimated"},
@@ -230,7 +230,7 @@ static RPCHelpMan generatetodescriptor()
         {
             {"num_blocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
             {"descriptor", RPCArg::Type::STR, RPCArg::Optional::NO, "The descriptor to send the newly generated coins to."},
-            {"maxtries", RPCArg::Type::NUM, /* default */ ToString(DEFAULT_MAX_TRIES), "How many iterations to try."},
+            {"maxtries", RPCArg::Type::NUM, RPCArg::Default{DEFAULT_MAX_TRIES}, "How many iterations to try."},
         },
         RPCResult{
             RPCResult::Type::ARR, "", "",
@@ -267,7 +267,7 @@ static RPCHelpMan generatetoaddress()
         {
             {"nblocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The address to send the newly generated coins to."},
-            {"maxtries", RPCArg::Type::NUM, /* default */ ToString(DEFAULT_MAX_TRIES), "How many iterations to try."},
+            {"maxtries", RPCArg::Type::NUM, RPCArg::Default{DEFAULT_MAX_TRIES}, "How many iterations to try."},
         },
         RPCResult{
             RPCResult::Type::ARR, "", "hashes of blocks generated",
@@ -563,7 +563,7 @@ static RPCHelpMan getblocktemplate()
         "    https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki\n"
         "    https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki#getblocktemplate_changes\n",
         {
-            {"template_request", RPCArg::Type::OBJ, /* default_val */ "", "Format of the template",
+            {"template_request", RPCArg::Type::OBJ, RPCArg::Default{UniValue::VOBJ}, "Format of the template",
                 {
                     {"mode", RPCArg::Type::STR, /* treat as named arg */ RPCArg::Optional::OMITTED_NAMED_ARG, "This must be set to \"template\", \"proposal\" (see BIP 23), or omitted"},
                     {"capabilities", RPCArg::Type::ARR, /* treat as named arg */ RPCArg::Optional::OMITTED_NAMED_ARG, "A list of strings",
@@ -1020,7 +1020,7 @@ static RPCHelpMan submitblock()
         "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n",
         {
             {"hexdata", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "the hex-encoded block data to submit"},
-            {"dummy", RPCArg::Type::STR, /* default */ "ignored", "dummy value, for compatibility with BIP22. This value is ignored."},
+            {"dummy", RPCArg::Type::STR, RPCArg::DefaultHint{"ignored"}, "dummy value, for compatibility with BIP22. This value is ignored."},
         },
         {
             RPCResult{"If the block was accepted", RPCResult::Type::NONE, "", ""},
@@ -1120,7 +1120,7 @@ static RPCHelpMan estimatesmartfee()
         "for which the estimate is valid.\n",
         {
             {"conf_target", RPCArg::Type::NUM, RPCArg::Optional::NO, "Confirmation target in blocks (1 - 1008)"},
-            {"estimate_mode", RPCArg::Type::STR, /* default */ "conservative", "The fee estimate mode.\n"
+            {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"conservative"}, "The fee estimate mode.\n"
     "                   Whether to return a more conservative estimate which also satisfies\n"
     "                   a longer history. A conservative estimate potentially returns a\n"
     "                   higher feerate and is more likely to be sufficient for the desired\n"
@@ -1195,7 +1195,7 @@ static RPCHelpMan estimaterawfee()
         "confirmation within conf_target blocks if possible.\n",
         {
             {"conf_target", RPCArg::Type::NUM, RPCArg::Optional::NO, "Confirmation target in blocks (1 - 1008)"},
-            {"threshold", RPCArg::Type::NUM, /* default */ "0.95", "The proportion of transactions in a given feerate range that must have been\n"
+            {"threshold", RPCArg::Type::NUM, RPCArg::Default{0.95}, "The proportion of transactions in a given feerate range that must have been\n"
     "               confirmed within conf_target in order to consider those feerates as high enough and proceed to check\n"
     "               lower buckets."},
         },
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index 6872f41115a19b..c052ee0d73f5de 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -709,9 +709,9 @@ static RPCHelpMan getaddressmempool()
     return RPCHelpMan{"getaddressmempool",
         "\nReturns all mempool deltas for an address (requires addressindex to be enabled).\n",
         {
-            {"addresses", RPCArg::Type::ARR, /* default */ "", "",
+            {"addresses", RPCArg::Type::ARR, RPCArg::DefaultHint{""}, "",
                 {
-                    {"address", RPCArg::Type::STR, /* default */ "", "The base58check encoded address"},
+                    {"address", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "The base58check encoded address"},
                 },
             },
         },
@@ -782,9 +782,9 @@ static RPCHelpMan getaddressutxos()
     return RPCHelpMan{"getaddressutxos",
         "\nReturns all unspent outputs for an address (requires addressindex to be enabled).\n",
         {
-            {"addresses", RPCArg::Type::ARR, /* default */ "", "",
+            {"addresses", RPCArg::Type::ARR, RPCArg::DefaultHint{""}, "",
                 {
-                    {"address", RPCArg::Type::STR, /* default */ "", "The base58check encoded address"},
+                    {"address", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "The base58check encoded address"},
                 },
             },
         },
@@ -855,9 +855,9 @@ static RPCHelpMan getaddressdeltas()
     return RPCHelpMan{"getaddressdeltas",
         "\nReturns all changes for an address (requires addressindex to be enabled).\n",
         {
-            {"addresses", RPCArg::Type::ARR, /* default */ "", "",
+            {"addresses", RPCArg::Type::ARR, RPCArg::DefaultHint{""}, "",
                 {
-                    {"address", RPCArg::Type::STR, /* default */ "", "The base58check encoded address"},
+                    {"address", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "The base58check encoded address"},
                 },
             },
         },
@@ -952,9 +952,9 @@ static RPCHelpMan getaddressbalance()
     return RPCHelpMan{"getaddressbalance",
         "\nReturns the balance for an address(es) (requires addressindex to be enabled).\n",
         {
-            {"addresses", RPCArg::Type::ARR, /* default */ "", "",
+            {"addresses", RPCArg::Type::ARR, RPCArg::DefaultHint{""}, "",
                 {
-                    {"address", RPCArg::Type::STR, /* default */ "", "The base58check encoded address"},
+                    {"address", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "The base58check encoded address"},
                 },
             },
         },
@@ -1029,9 +1029,9 @@ static RPCHelpMan getaddresstxids()
     return RPCHelpMan{"getaddresstxids",
         "\nReturns the txids for an address(es) (requires addressindex to be enabled).\n",
         {
-            {"addresses", RPCArg::Type::ARR, /* default */ "", "",
+            {"addresses", RPCArg::Type::ARR, RPCArg::DefaultHint{""}, "",
                 {
-                    {"address", RPCArg::Type::STR, /* default */ "", "The base58check encoded address"},
+                    {"address", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "The base58check encoded address"},
                 },
             },
         },
@@ -1116,10 +1116,10 @@ static RPCHelpMan getspentinfo()
     return RPCHelpMan{"getspentinfo",
         "\nReturns the txid and index where an output is spent.\n",
         {
-            {"request", RPCArg::Type::OBJ, /* default */ "", "",
+            {"request", RPCArg::Type::OBJ, RPCArg::Default{UniValue::VOBJ}, "",
                 {
-                    {"txid", RPCArg::Type::STR_HEX, /* default */ "", "The hex string of the txid"},
-                    {"index", RPCArg::Type::NUM, /* default */ "", "The start block height"},
+                    {"txid", RPCArg::Type::STR_HEX, RPCArg::DefaultHint{""}, "The hex string of the txid"},
+                    {"index", RPCArg::Type::NUM, RPCArg::DefaultHint{""}, "The start block height"},
                 },
             },
         },
@@ -1238,7 +1238,7 @@ static RPCHelpMan getmemoryinfo()
     return RPCHelpMan{"getmemoryinfo",
         "Returns an object containing information about memory usage.\n",
         {
-            {"mode", RPCArg::Type::STR, /* default */ "\"stats\"", "determines what kind of information is returned.\n"
+            {"mode", RPCArg::Type::STR, RPCArg::Default{"stats"}, "determines what kind of information is returned.\n"
     "  - \"stats\" returns general statistics about memory usage in the daemon.\n"
     "  - \"mallocinfo\" returns an XML string describing low-level heap state (only available if compiled with glibc 2.10+)."},
         },
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index b8bdd38939b565..e22318e55c1098 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -408,8 +408,8 @@ static RPCHelpMan disconnectnode()
         "\nStrictly one out of 'address' and 'nodeid' can be provided to identify the node.\n"
         "\nTo disconnect by nodeid, either set 'address' to the empty string, or call using the named 'nodeid' argument only.\n",
         {
-            {"address", RPCArg::Type::STR, /* default */ "fallback to nodeid", "The IP address/port of the node"},
-            {"nodeid", RPCArg::Type::NUM, /* default */ "fallback to address", "The node ID (see getpeerinfo for node IDs)"},
+            {"address", RPCArg::Type::STR, RPCArg::DefaultHint{"fallback to nodeid"}, "The IP address/port of the node"},
+            {"nodeid", RPCArg::Type::NUM, RPCArg::DefaultHint{"fallback to address"}, "The node ID (see getpeerinfo for node IDs)"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -454,7 +454,7 @@ static RPCHelpMan getaddednodeinfo()
                 "\nReturns information about the given added node, or all added nodes\n"
                 "(note that onetry addnodes are not listed here)\n",
                 {
-                    {"node", RPCArg::Type::STR, /* default */ "all nodes", "If provided, return information about this specific node, otherwise all nodes are returned."},
+                    {"node", RPCArg::Type::STR, RPCArg::DefaultHint{"all nodes"}, "If provided, return information about this specific node, otherwise all nodes are returned."},
                 },
                 RPCResult{
                     RPCResult::Type::ARR, "", "",
@@ -706,8 +706,8 @@ static RPCHelpMan setban()
                 {
                     {"subnet", RPCArg::Type::STR, RPCArg::Optional::NO, "The IP/Subnet (see getpeerinfo for nodes IP) with an optional netmask (default is /32 = single IP)"},
                     {"command", RPCArg::Type::STR, RPCArg::Optional::NO, "'add' to add an IP/Subnet to the list, 'remove' to remove an IP/Subnet from the list"},
-                    {"bantime", RPCArg::Type::NUM, /* default */ "0", "time in seconds how long (or until when if [absolute] is set) the IP is banned (0 or empty means using the default time of 24h which can also be overwritten by the -bantime startup argument)"},
-                    {"absolute", RPCArg::Type::BOOL, /* default */ "false", "If set, the bantime must be an absolute timestamp expressed in " + UNIX_EPOCH_TIME},
+                    {"bantime", RPCArg::Type::NUM, RPCArg::Default{0}, "time in seconds how long (or until when if [absolute] is set) the IP is banned (0 or empty means using the default time of 24h which can also be overwritten by the -bantime startup argument)"},
+                    {"absolute", RPCArg::Type::BOOL, RPCArg::Default{false}, "If set, the bantime must be an absolute timestamp expressed in " + UNIX_EPOCH_TIME},
                 },
                 RPCResult{RPCResult::Type::NONE, "", ""},
                 RPCExamples{
@@ -909,8 +909,8 @@ static RPCHelpMan getnodeaddresses()
     return RPCHelpMan{"getnodeaddresses",
                 "\nReturn known addresses, which can potentially be used to find new nodes in the network.\n",
                 {
-                    {"count", RPCArg::Type::NUM, /* default */ "1", "The maximum number of addresses to return. Specify 0 to return all known addresses."},
-                    {"network", RPCArg::Type::STR, /* default */ "all networks", "Return only addresses of the specified network. Can be one of: " + Join(GetNetworkNames(), ", ") + "."},
+                    {"count", RPCArg::Type::NUM, RPCArg::Default{1}, "The maximum number of addresses to return. Specify 0 to return all known addresses."},
+                    {"network", RPCArg::Type::STR, RPCArg::DefaultHint{"all networks"}, "Return only addresses of the specified network. Can be one of: " + Join(GetNetworkNames(), ", ") + "."},
                 },
                 RPCResult{
                     RPCResult::Type::ARR, "", "",
@@ -970,7 +970,7 @@ static RPCHelpMan addpeeraddress()
         {
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The IP address of the peer"},
             {"port", RPCArg::Type::NUM, RPCArg::Optional::NO, "The port of the peer"},
-            {"tried", RPCArg::Type::BOOL, /* default */ "false", "If true, attempt to add the peer to the tried addresses table"},
+            {"tried", RPCArg::Type::BOOL, RPCArg::Default{false}, "If true, attempt to add the peer to the tried addresses table"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index fa8994c70aa865..f5dadbcfebc60a 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -131,7 +131,7 @@ static RPCHelpMan getrawtransaction()
             "If verbose is 'false' or omitted, returns a string that is serialized, hex-encoded data for 'txid'.\n",
                 {
                     {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
-                    {"verbose", RPCArg::Type::BOOL, /* default */ "false", "If false, return a string, otherwise return a json object"},
+                    {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "If false, return a string, otherwise return a json object"},
                     {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED_NAMED_ARG, "The block in which to look for the transaction"},
                 },
                 {
@@ -290,7 +290,7 @@ static RPCHelpMan getrawtransactionmulti() {
                                       {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "The transaction id"},
                               }},
                      }},
-                    {"verbose", RPCArg::Type::BOOL, /* default */ "false",
+                    {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false},
                      "If false, return a string, otherwise return a json object"},
             },
             RPCResults{},
@@ -744,7 +744,7 @@ static RPCHelpMan createrawtransaction()
                         {
                             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
-                            {"sequence", RPCArg::Type::NUM, /* default */ "", "The sequence number"},
+                            {"sequence", RPCArg::Type::NUM, RPCArg::DefaultHint{""}, "The sequence number"},
                         },
                         },
                 },
@@ -766,7 +766,7 @@ static RPCHelpMan createrawtransaction()
                         },
                 },
                 },
-            {"locktime", RPCArg::Type::NUM, /* default */ "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
+            {"locktime", RPCArg::Type::NUM, RPCArg::Default{0}, "Raw locktime. Non-0 value also locktime-activates inputs"},
         },
         RPCResult{
             RPCResult::Type::STR_HEX, "transaction", "hex string of the transaction"
@@ -1047,7 +1047,7 @@ static RPCHelpMan signrawtransactionwithkey()
                     },
                 },
             },
-            {"sighashtype", RPCArg::Type::STR, /* default */ "ALL", "The signature hash type. Must be one of:\n"
+            {"sighashtype", RPCArg::Type::STR, RPCArg::Default{"ALL"}, "The signature hash type. Must be one of:\n"
     "       \"ALL\"\n"
     "       \"NONE\"\n"
     "       \"SINGLE\"\n"
@@ -1126,7 +1126,7 @@ RPCHelpMan sendrawtransaction()
                 "\nRelated RPCs: createrawtransaction, signrawtransactionwithkey\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of the raw transaction"},
-                    {"maxfeerate", RPCArg::Type::AMOUNT, /* default */ FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK()),
+                    {"maxfeerate", RPCArg::Type::AMOUNT, RPCArg::Default{FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK())},
                         "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT +
                             "/kB.\nSet to 0 to accept any fee rate.\n"},
                     {"instantsend", RPCArg::Type::BOOL, RPCArg::Optional::OMITTED, "Deprecated and ignored"},
@@ -1196,7 +1196,7 @@ static RPCHelpMan testmempoolaccept()
                             {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
                         },
                         },
-                    {"maxfeerate", RPCArg::Type::AMOUNT, /* default */ FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK()),
+                    {"maxfeerate", RPCArg::Type::AMOUNT, RPCArg::Default{FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK())},
                      "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT + "/kB\n"},
                 },
                 RPCResult{
@@ -1631,7 +1631,7 @@ static RPCHelpMan finalizepsbt()
                 "Implements the Finalizer and Extractor roles.\n",
                 {
                     {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO, "A base64 string of a PSBT"},
-                    {"extract", RPCArg::Type::BOOL, /* default */ "true", "If true and the transaction is complete,\n"
+                    {"extract", RPCArg::Type::BOOL, RPCArg::Default{true}, "If true and the transaction is complete,\n"
             "                             extract and return the complete transaction in normal network serialization instead of the PSBT."},
                 },
                 RPCResult{
@@ -1693,7 +1693,7 @@ static RPCHelpMan createpsbt()
                         {
                             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
-                            {"sequence", RPCArg::Type::NUM, /* default */ "depends on the value of 'locktime' argument", "The sequence number"},
+                            {"sequence", RPCArg::Type::NUM, RPCArg::DefaultHint{"depends on the value of 'locktime' argument"}, "The sequence number"},
                         },
                         },
                 },
@@ -1715,7 +1715,7 @@ static RPCHelpMan createpsbt()
                         },
                 },
                 },
-            {"locktime", RPCArg::Type::NUM, /* default */ "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
+            {"locktime", RPCArg::Type::NUM, RPCArg::Default{0}, "Raw locktime. Non-0 value also locktime-activates inputs"},
         },
         RPCResult{
             RPCResult::Type::STR, "", "The resulting raw transaction (base64-encoded string)"
@@ -1761,7 +1761,7 @@ static RPCHelpMan converttopsbt()
                 "createpsbt and walletcreatefundedpsbt should be used for new applications.\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of a raw transaction"},
-                    {"permitsigdata", RPCArg::Type::BOOL, /* default */ "false", "If true, any signatures in the input will be discarded and conversion\n"
+                    {"permitsigdata", RPCArg::Type::BOOL, RPCArg::Default{false}, "If true, any signatures in the input will be discarded and conversion\n"
                             "                              will continue. If false, RPC will fail if any signatures are present."},
                 },
                 RPCResult{
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index 7af6478c0f7257..8b101018d43208 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -168,8 +168,8 @@ static RPCHelpMan help()
     return RPCHelpMan{"help",
         "\nList all commands, or get help for a specified command.\n",
         {
-            {"command", RPCArg::Type::STR, /* default */ "all commands", "The command to get help on"},
-            {"subcommand", RPCArg::Type::STR, /* default */ "all subcommands", "The subcommand to get help on."},
+            {"command", RPCArg::Type::STR, RPCArg::DefaultHint{"all commands"}, "The command to get help on"},
+            {"subcommand", RPCArg::Type::STR, RPCArg::DefaultHint{"all subcommands"}, "The subcommand to get help on."},
         },
         {
             RPCResult{RPCResult::Type::STR, "", "The help text"},
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 3b02da632f693f..f6d530688dbb2a 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -469,6 +469,33 @@ RPCHelpMan::RPCHelpMan(std::string name, std::string description, std::vector<RP
         for (const std::string& name : names) {
             CHECK_NONFATAL(named_args.insert(name).second);
         }
+        // Default value type should match argument type only when defined
+        if (arg.m_fallback.index() == 2) {
+            const RPCArg::Type type = arg.m_type;
+            switch (std::get<RPCArg::Default>(arg.m_fallback).getType()) {
+            case UniValue::VOBJ:
+                CHECK_NONFATAL(type == RPCArg::Type::OBJ);
+                break;
+            case UniValue::VARR:
+                CHECK_NONFATAL(type == RPCArg::Type::ARR);
+                break;
+            case UniValue::VSTR:
+                CHECK_NONFATAL(type == RPCArg::Type::STR || type == RPCArg::Type::STR_HEX || type == RPCArg::Type::AMOUNT);
+                break;
+            case UniValue::VNUM:
+                CHECK_NONFATAL(type == RPCArg::Type::NUM || type == RPCArg::Type::AMOUNT || type == RPCArg::Type::RANGE);
+                break;
+            case UniValue::VBOOL:
+                CHECK_NONFATAL(type == RPCArg::Type::BOOL);
+                break;
+            case UniValue::VNULL:
+                // Null values are accepted in all arguments
+                break;
+            default:
+                CHECK_NONFATAL(false);
+                break;
+            }
+        }
     }
 }
 
@@ -614,7 +641,7 @@ std::string RPCArg::GetName() const
 
 bool RPCArg::IsOptional() const
 {
-    if (m_fallback.index() == 1) {
+    if (m_fallback.index() != 0) {
         return true;
     } else {
         return RPCArg::Optional::NO != std::get<RPCArg::Optional>(m_fallback);
@@ -662,7 +689,9 @@ std::string RPCArg::ToDescriptionString() const
         } // no default case, so the compiler can warn about missing cases
     }
     if (m_fallback.index() == 1) {
-        ret += ", optional, default=" + std::get<std::string>(m_fallback);
+        ret += ", optional, default=" + std::get<RPCArg::DefaultHint>(m_fallback);
+    } else if (m_fallback.index() == 2) {
+        ret += ", optional, default=" + std::get<RPCArg::Default>(m_fallback).write();
     } else {
         switch (std::get<RPCArg::Optional>(m_fallback)) {
         case RPCArg::Optional::OMITTED: {
diff --git a/src/rpc/util.h b/src/rpc/util.h
index 189551cd037937..b97b4ca436c317 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -148,7 +148,9 @@ struct RPCArg {
          */
         OMITTED,
     };
-    using Fallback = std::variant<Optional, /* default value for optional args */ std::string>;
+    using DefaultHint = std::string;
+    using Default = UniValue;
+    using Fallback = std::variant<Optional, /* hint for default value */ DefaultHint, /* default constant value */ Default>;
     const std::string m_names; //!< The name of the arg (can be empty for inner args, can contain multiple aliases separated by | for named request arguments)
     const Type m_type;
     const bool m_hidden;
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 16ac2596ab11d4..688ab53aae5ace 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -80,8 +80,8 @@ RPCHelpMan importprivkey()
     "may report that the imported key exists but related transactions are still missing, leading to temporarily incorrect/bogus balances and unspent outputs until rescan completes.\n",
         {
             {"privkey", RPCArg::Type::STR, RPCArg::Optional::NO, "The private key (see dumpprivkey)"},
-            {"label", RPCArg::Type::STR, /* default */ "current label if address exists, otherwise \"\"", "An optional label"},
-            {"rescan", RPCArg::Type::BOOL, /* default */ "true", "Rescan the wallet for transactions"},
+            {"label", RPCArg::Type::STR, RPCArg::DefaultHint{"current label if address exists, otherwise \"\""}, "An optional label"},
+            {"rescan", RPCArg::Type::BOOL, RPCArg::Default{true}, "Rescan the wallet for transactions"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -200,9 +200,9 @@ RPCHelpMan importaddress()
     "as change, and not show up in many RPCs.\n",
         {
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The Dash address (or hex-encoded script)"},
-            {"label", RPCArg::Type::STR, /* default */ "\"\"", "An optional label"},
-            {"rescan", RPCArg::Type::BOOL, /* default */ "true", "Rescan the wallet for transactions"},
-            {"p2sh", RPCArg::Type::BOOL, /* default */ "false", "Add the P2SH version of the script as well"},
+            {"label", RPCArg::Type::STR, RPCArg::Default{""}, "An optional label"},
+            {"rescan", RPCArg::Type::BOOL, RPCArg::Default{true}, "Rescan the wallet for transactions"},
+            {"p2sh", RPCArg::Type::BOOL, RPCArg::Default{false}, "Add the P2SH version of the script as well"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -393,8 +393,8 @@ RPCHelpMan importpubkey()
     "may report that the imported pubkey exists but related transactions are still missing, leading to temporarily incorrect/bogus balances and unspent outputs until rescan completes.\n",
         {
             {"pubkey", RPCArg::Type::STR, RPCArg::Optional::NO, "The hex-encoded public key"},
-            {"label", RPCArg::Type::STR, /* default */ "\"\"", "An optional label"},
-            {"rescan", RPCArg::Type::BOOL, /* default */ "true", "Rescan the wallet for transactions"},
+            {"label", RPCArg::Type::STR, RPCArg::Default{""}, "An optional label"},
+            {"rescan", RPCArg::Type::BOOL, RPCArg::Default{true}, "Rescan the wallet for transactions"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -634,7 +634,7 @@ RPCHelpMan importelectrumwallet()
         "\nImports keys from an Electrum wallet export file (.csv or .json)\n",
         {
             {"filename", RPCArg::Type::STR, RPCArg::Optional::NO, "The Electrum wallet export file, should be in csv or json format"},
-            {"index", RPCArg::Type::NUM, /* default */ "0", "Rescan the wallet for transactions starting from this block index"},
+            {"index", RPCArg::Type::NUM, RPCArg::Default{0}, "Rescan the wallet for transactions starting from this block index"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -1462,7 +1462,7 @@ RPCHelpMan importmulti()
                 {
                     {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                         {
-                            {"desc", RPCArg::Type::STR, /* default */ "", "Descriptor to import. If using descriptor, do not also provide address/scriptPubKey, scripts, or pubkeys"
+                            {"desc", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "Descriptor to import. If using descriptor, do not also provide address/scriptPubKey, scripts, or pubkeys"
                             },
                             {"scriptPubKey", RPCArg::Type::STR, RPCArg::Optional::NO, "Type of scriptPubKey (string for script, json for address). Should not be provided if using a descriptor",
                                 /* oneline_description */ "", {"\"<script>\" | { \"address\":\"<address>\" }", "string / json"}
@@ -1476,28 +1476,28 @@ RPCHelpMan importmulti()
                                 /* oneline_description */ "", {"timestamp | \"now\"", "integer / string"}
                             },
                             {"redeemscript", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Allowed only if the scriptPubKey is a P2SH address or  a P2SH scriptPubKey"},
-                            {"pubkeys", RPCArg::Type::ARR, /* default */ "empty array", "Array of strings giving pubkeys to import. They must occur in P2PKH scripts. They are not required when the private key is also provided (see the \"keys\" argument).",
+                            {"pubkeys", RPCArg::Type::ARR, RPCArg::DefaultHint{"empty array"}, "Array of strings giving pubkeys to import. They must occur in P2PKH scripts. They are not required when the private key is also provided (see the \"keys\" argument).",
                                 {
                                     {"pubKey", RPCArg::Type::STR, RPCArg::Optional::OMITTED, ""},
                                 }
                             },
-                            {"keys", RPCArg::Type::ARR, /* default */ "empty array", "Array of strings giving private keys whose  corresponding public keys must occur in the output or redeemscript.",
+                            {"keys", RPCArg::Type::ARR, RPCArg::DefaultHint{"empty array"}, "Array of strings giving private keys whose  corresponding public keys must occur in the output or redeemscript.",
                                 {
                                     {"key", RPCArg::Type::STR, RPCArg::Optional::OMITTED, ""},
                                 }
                             },
                             {"range", RPCArg::Type::RANGE, RPCArg::Optional::OMITTED, "If a ranged descriptor is used, this specifies the end or the range (in the form [begin,end]) to import"},
-                            {"internal", RPCArg::Type::BOOL, /* default */ "false", "Stating whether matching outputs should be treated as not incoming payments (also known as change)"},
-                            {"watchonly", RPCArg::Type::BOOL, /* default */ "false", "Stating whether matching outputs should be considered watchonly."},
-                            {"label", RPCArg::Type::STR, /* default */ "''", "Label to assign to the address, only allowed with internal=false"},
-                            {"keypool", RPCArg::Type::BOOL, /* default */ "false", "Stating whether imported public keys should be added to the keypool for when users request new addresses. Only allowed when wallet private keys are disabled"},
+                            {"internal", RPCArg::Type::BOOL, RPCArg::Default{false}, "Stating whether matching outputs should be treated as not incoming payments (also known as change)"},
+                            {"watchonly", RPCArg::Type::BOOL, RPCArg::Default{false}, "Stating whether matching outputs should be considered watchonly."},
+                            {"label", RPCArg::Type::STR, RPCArg::Default{""}, "Label to assign to the address, only allowed with internal=false"},
+                            {"keypool", RPCArg::Type::BOOL, RPCArg::Default{false}, "Stating whether imported public keys should be added to the keypool for when users request new addresses. Only allowed when wallet private keys are disabled"},
                         },
                     },
                 },
                 "\"requests\""},
             {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                 {
-                    {"rescan", RPCArg::Type::BOOL, /* default */ "true", "Stating if should rescan the blockchain after all imports"},
+                    {"rescan", RPCArg::Type::BOOL, RPCArg::Default{true}, "Stating if should rescan the blockchain after all imports"},
                 },
                 "\"options\""},
         },
@@ -1791,7 +1791,7 @@ RPCHelpMan importdescriptors() {
                             {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                                 {
                                     {"desc", RPCArg::Type::STR, RPCArg::Optional::NO, "Descriptor to import."},
-                                    {"active", RPCArg::Type::BOOL, /* default */ "false", "Set this descriptor to be the active descriptor for the corresponding output type/externality"},
+                                    {"active", RPCArg::Type::BOOL, RPCArg::Default{false}, "Set this descriptor to be the active descriptor for the corresponding output type/externality"},
                                     {"range", RPCArg::Type::RANGE, RPCArg::Optional::OMITTED, "If a ranged descriptor is used, this specifies the end or the range (in the form [begin,end]) to import"},
                                     {"next_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "If a ranged descriptor is set to active, this specifies the next index to generate addresses from"},
                                     {"timestamp", RPCArg::Type::NUM, RPCArg::Optional::NO, "Time from which to start rescanning the blockchain for this descriptor, in " + UNIX_EPOCH_TIME + "\n"
@@ -1801,8 +1801,8 @@ RPCHelpMan importdescriptors() {
         "                                                              of all descriptors being imported will be scanned.",
                                         /* oneline_description */ "", {"timestamp | \"now\"", "integer / string"}
                                     },
-                                    {"internal", RPCArg::Type::BOOL, /* default */ "false", "Whether matching outputs should be treated as not incoming payments (e.g. change)"},
-                                    {"label", RPCArg::Type::STR, /* default */ "''", "Label to assign to the address, only allowed with internal=false"},
+                                    {"internal", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether matching outputs should be treated as not incoming payments (e.g. change)"},
+                                    {"label", RPCArg::Type::STR, RPCArg::Default{""}, "Label to assign to the address, only allowed with internal=false"},
                                 },
                             },
                         },
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 235882f288a30e..f32c2581884cd1 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -243,7 +243,7 @@ RPCHelpMan getnewaddress()
         "If 'label' is specified, it is added to the address book \n"
         "so payments received with the address will be associated with 'label'.\n",
         {
-            {"label", RPCArg::Type::STR, /* default */ "\"\"", "The label name for the address to be linked to. It can also be set to the empty string \"\" to represent the default label. The label does not need to exist, it will be created if there is no label by the given name."},
+            {"label", RPCArg::Type::STR, RPCArg::Default{""}, "The label name for the address to be linked to. It can also be set to the empty string \"\" to represent the default label. The label does not need to exist, it will be created if there is no label by the given name."},
         },
         RPCResult{
     RPCResult::Type::STR, "address", "The new Dash address"
@@ -422,16 +422,16 @@ static RPCHelpMan sendtoaddress()
             {"comment_to", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "A comment to store the name of the person or organization\n"
                 "to which you're sending the transaction. This is not part of the \n"
                 "transaction, just kept in your wallet."},
-            {"subtractfeefromamount", RPCArg::Type::BOOL, /* default */ "false", "The fee will be deducted from the amount being sent.\n"
+            {"subtractfeefromamount", RPCArg::Type::BOOL, RPCArg::Default{false}, "The fee will be deducted from the amount being sent.\n"
                 "The recipient will receive less amount of Dash than you enter in the amount field."},
-            {"use_is", RPCArg::Type::BOOL, /* default */ "false", "Deprecated and ignored"},
-            {"use_cj", RPCArg::Type::BOOL, /* default */ "false", "Use CoinJoin funds only"},
-            {"conf_target", RPCArg::Type::NUM, /* default */ "wallet default", "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
-            {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+            {"use_is", RPCArg::Type::BOOL, RPCArg::Default{false}, "Deprecated and ignored"},
+            {"use_cj", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use CoinJoin funds only"},
+            {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet default"}, "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
+            {"estimate_mode", RPCArg::Type::STR, RPCArg::DefaultHint{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
             "       \"" + FeeModes("\"\n\"") + "\""},
-            {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "true", "(only available if avoid_reuse wallet flag is set) Avoid spending from dirty addresses; addresses are considered\n"
+            {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{true}, "(only available if avoid_reuse wallet flag is set) Avoid spending from dirty addresses; addresses are considered\n"
     "                             dirty if they have previously been used in a transaction."},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "false", "If true, return extra information about the transaction."},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "If true, return extra information about the transaction."},
         },
                 {
                     RPCResult{"if verbose is not set or set to false",
@@ -589,7 +589,7 @@ static RPCHelpMan listaddressbalances()
     return RPCHelpMan{"listaddressbalances",
         "\nLists addresses of this wallet and their balances\n",
         {
-            {"minamount", RPCArg::Type::NUM, /* default */ "0", "Minimum balance in " + CURRENCY_UNIT + " an address should have to be shown in the list"},
+            {"minamount", RPCArg::Type::NUM, RPCArg::Default{0}, "Minimum balance in " + CURRENCY_UNIT + " an address should have to be shown in the list"},
         },
         RPCResult{
             RPCResult::Type::ARR, "", "",
@@ -739,8 +739,8 @@ static RPCHelpMan getreceivedbyaddress()
         "\nReturns the total amount received by the given address in transactions with at least minconf confirmations.\n",
         {
             {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The Dash address for transactions."},
-            {"minconf", RPCArg::Type::NUM, /* default */ "1", "Only include transactions confirmed at least this many times."},
-            {"addlocked", RPCArg::Type::BOOL, /* default */ "false", "Whether to include transactions locked via InstantSend."},
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "Only include transactions confirmed at least this many times."},
+            {"addlocked", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include transactions locked via InstantSend."},
         },
         RPCResult{
             RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " received at this address."
@@ -778,8 +778,8 @@ static RPCHelpMan getreceivedbylabel()
         "\nReturns the total amount received by addresses with <label> in transactions with specified minimum number of confirmations.\n",
         {
             {"label", RPCArg::Type::STR, RPCArg::Optional::NO, "The selected label, may be the default label using \"\"."},
-            {"minconf", RPCArg::Type::NUM, /* default */ "1", "Only include transactions confirmed at least this many times."},
-            {"addlocked", RPCArg::Type::BOOL, /* default */ "false", "Whether to include transactions locked via InstantSend."},
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "Only include transactions confirmed at least this many times."},
+            {"addlocked", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include transactions locked via InstantSend."},
         },
         RPCResult{
             RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " received for this label."
@@ -819,10 +819,10 @@ static RPCHelpMan getbalance()
         "thus affected by options which limit spendability such as -spendzeroconfchange.\n",
         {
             {"dummy", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "Remains for backward compatibility. Must be excluded or set to \"*\"."},
-            {"minconf", RPCArg::Type::NUM, /* default */ "0", "Only include transactions confirmed at least this many times."},
-            {"addlocked", RPCArg::Type::BOOL, /* default */ "false", "Whether to include transactions locked via InstantSend in the wallet's balance."},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Also include balance in watch-only addresses (see 'importaddress')"},
-            {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "true", "(only available if avoid_reuse wallet flag is set) Do not include balance in dirty outputs; addresses are considered dirty if they have previously been used in a transaction. If true, this also activates avoidpartialspends, grouping outputs by their addresses."},
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{0}, "Only include transactions confirmed at least this many times."},
+            {"addlocked", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include transactions locked via InstantSend in the wallet's balance."},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets}, otherwise false"} , "Also include balance in watch-only addresses (see 'importaddress')"},
+            {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{true}, "(only available if avoid_reuse wallet flag is set) Do not include balance in dirty outputs; addresses are considered dirty if they have previously been used in a transaction. If true, this also activates avoidpartialspends, grouping outputs by their addresses."},
         },
         RPCResult{
             RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " received for this wallet."
@@ -919,12 +919,12 @@ static RPCHelpMan sendmany()
                             {"address", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Subtract fee from this address"},
                         },
                     },
-                    {"use_is", RPCArg::Type::BOOL, /* default */ "false", "Deprecated and ignored"},
-                    {"use_cj", RPCArg::Type::BOOL, /* default */ "false", "Use CoinJoin funds only"},
-                    {"conf_target", RPCArg::Type::NUM, /* default */ "wallet default", "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
-                    {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+                    {"use_is", RPCArg::Type::BOOL, RPCArg::Default{false}, "Deprecated and ignored"},
+                    {"use_cj", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use CoinJoin funds only"},
+                    {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet default"}, "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
+                    {"estimate_mode", RPCArg::Type::STR, RPCArg::DefaultHint{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
             "       \"" + FeeModes("\"\n\"") + "\""},
-                    {"verbose", RPCArg::Type::BOOL, /* default */ "false", "If true, return extra infomration about the transaction."},
+                    {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "If true, return extra infomration about the transaction."},
                 },
                 {
                     RPCResult{"if verbose is not set or set to false",
@@ -1234,10 +1234,10 @@ static RPCHelpMan listreceivedbyaddress()
     return RPCHelpMan{"listreceivedbyaddress",
         "\nList balances by receiving address.\n",
         {
-            {"minconf", RPCArg::Type::NUM, /* default */ "1", "The minimum number of confirmations before payments are included."},
-            {"addlocked", RPCArg::Type::BOOL, /* default */ "false", "Whether to include transactions locked via InstantSend."},
-            {"include_empty", RPCArg::Type::BOOL, /* default */ "false", "Whether to include addresses that haven't received any payments."},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Whether to include watch-only addresses (see 'importaddress')"},
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "The minimum number of confirmations before payments are included."},
+            {"addlocked", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include transactions locked via InstantSend."},
+            {"include_empty", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include addresses that haven't received any payments."},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Whether to include watch-only addresses (see 'importaddress')"},
             {"address_filter", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "If present, only return information on this address."},
         },
         RPCResult{
@@ -1286,10 +1286,10 @@ static RPCHelpMan listreceivedbylabel()
     return RPCHelpMan{"listreceivedbylabel",
         "\nList received transactions by label.\n",
         {
-            {"minconf", RPCArg::Type::NUM, /* default */ "1", "The minimum number of confirmations before payments are included."},
-            {"addlocked", RPCArg::Type::BOOL, /* default */ "false", "Whether to include transactions locked via InstantSend."},
-            {"include_empty", RPCArg::Type::BOOL, /* default */ "false", "Whether to include labels that haven't received any payments."},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Whether to include watch-only addresses (see 'importaddress')"},
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "The minimum number of confirmations before payments are included."},
+            {"addlocked", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include transactions locked via InstantSend."},
+            {"include_empty", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include labels that haven't received any payments."},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Whether to include watch-only addresses (see 'importaddress')"},
         },
         RPCResult{
             RPCResult::Type::ARR, "", "",
@@ -1455,9 +1455,9 @@ static RPCHelpMan listtransactions()
         {
             {"label|dummy", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "If set, should be a valid label name to return only incoming transactions\n"
                   "with the specified label, or \"*\" to disable filtering and return all transactions."},
-            {"count", RPCArg::Type::NUM, /* default */ "10", "The number of transactions to return"},
-            {"skip", RPCArg::Type::NUM, /* default */ "0", "The number of transactions to skip"},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Include transactions to watch-only addresses (see 'importaddress')"},
+            {"count", RPCArg::Type::NUM, RPCArg::Default{10}, "The number of transactions to return"},
+            {"skip", RPCArg::Type::NUM, RPCArg::Default{0}, "The number of transactions to skip"},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Include transactions to watch-only addresses (see 'importaddress')"},
         },
         RPCResult{
             RPCResult::Type::ARR, "", "",
@@ -1569,9 +1569,9 @@ static RPCHelpMan listsinceblock()
         "Additionally, if include_removed is set, transactions affecting the wallet which were removed are returned in the \"removed\" array.\n",
         {
             {"blockhash", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "If set, the block hash to list transactions since, otherwise list all transactions."},
-            {"target_confirmations", RPCArg::Type::NUM, /* default */ "1", "Return the nth block hash from the main chain. e.g. 1 would mean the best block hash. Note: this is not used as a filter, but only affects [lastblock] in the return value"},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Include transactions to watch-only addresses (see 'importaddress')"},
-            {"include_removed", RPCArg::Type::BOOL, /* default */ "true", "Show transactions that were removed due to a reorg in the \"removed\" array\n"
+            {"target_confirmations", RPCArg::Type::NUM, RPCArg::Default{1}, "Return the nth block hash from the main chain. e.g. 1 would mean the best block hash. Note: this is not used as a filter, but only affects [lastblock] in the return value"},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Include transactions to watch-only addresses (see 'importaddress')"},
+            {"include_removed", RPCArg::Type::BOOL, RPCArg::Default{true}, "Show transactions that were removed due to a reorg in the \"removed\" array\n"
                 "(not guaranteed to work on pruned nodes)"},
         },
         RPCResult{
@@ -1707,8 +1707,8 @@ static RPCHelpMan gettransaction()
         "\nGet detailed information about in-wallet transaction <txid>\n",
         {
             {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
-            {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Whether to include watch-only addresses in balance calculation and details[]"},
-            {"verbose", RPCArg::Type::BOOL, /* default */ "false", "Whether to include a `decoded` field containing the decoded transaction (equivalent to RPC decoderawtransaction)"},
+            {"include_watchonly", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Whether to include watch-only addresses in balance calculation and details[]"},
+            {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to include a `decoded` field containing the decoded transaction (equivalent to RPC decoderawtransaction)"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "", Cat(Cat<std::vector<RPCResult>>(
@@ -1893,7 +1893,7 @@ static RPCHelpMan keypoolrefill()
         "\nFills the keypool."+
                 HELP_REQUIRING_PASSPHRASE,
         {
-            {"newsize", RPCArg::Type::NUM, /* default */ ToString(DEFAULT_KEYPOOL_SIZE), "The new keypool size"},
+            {"newsize", RPCArg::Type::NUM, RPCArg::Default{(int)DEFAULT_KEYPOOL_SIZE}, "The new keypool size"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -1943,7 +1943,7 @@ static RPCHelpMan walletpassphrase()
         {
             {"passphrase", RPCArg::Type::STR, RPCArg::Optional::NO, "The wallet passphrase"},
             {"timeout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The time to keep the decryption key in seconds; capped at 100000000 (~3 years)."},
-            {"mixingonly", RPCArg::Type::BOOL, /* default */ "false", "If is true sending functions are disabled."},
+            {"mixingonly", RPCArg::Type::BOOL, RPCArg::Default{false}, "If is true sending functions are disabled."},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -2199,7 +2199,7 @@ static RPCHelpMan lockunspent()
         "Also see the listunspent call\n",
         {
             {"unlock", RPCArg::Type::BOOL, RPCArg::Optional::NO, "Whether to unlock (true) or lock (false) the specified transactions"},
-            {"transactions", RPCArg::Type::ARR, /* default */ "empty array", "The transaction outputs and within each, the txid (string) vout (numeric).",
+            {"transactions", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "The transaction outputs and within each, the txid (string) vout (numeric).",
                 {
                     {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
                         {
@@ -2775,10 +2775,10 @@ static RPCHelpMan upgradetohd()
         "\npassphrase may result in your wallet getting locked.\n"
         "\nWarning: You will need to make a new backup of your wallet after setting the HD wallet mnemonic.\n",
         {
-            {"mnemonic", RPCArg::Type::STR, /* default */ "", "Mnemonic as defined in BIP39 to use for the new HD wallet. Use an empty string \"\" to generate a new random mnemonic."},
-            {"mnemonicpassphrase", RPCArg::Type::STR, /* default */ "", "Optional mnemonic passphrase as defined in BIP39"},
-            {"walletpassphrase", RPCArg::Type::STR, /* default */ "", "If your wallet is encrypted you must have your wallet passphrase here. If your wallet is not encrypted, specifying wallet passphrase will trigger wallet encryption."},
-            {"rescan", RPCArg::Type::BOOL, /* default */ "false if mnemonic is empty", "Whether to rescan the blockchain for missing transactions or not"},
+            {"mnemonic", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "Mnemonic as defined in BIP39 to use for the new HD wallet. Use an empty string \"\" to generate a new random mnemonic."},
+            {"mnemonicpassphrase", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "Optional mnemonic passphrase as defined in BIP39"},
+            {"walletpassphrase", RPCArg::Type::STR, RPCArg::DefaultHint{""}, "If your wallet is encrypted you must have your wallet passphrase here. If your wallet is not encrypted, specifying wallet passphrase will trigger wallet encryption."},
+            {"rescan", RPCArg::Type::BOOL, RPCArg::DefaultHint{"false if mnemonic is empty"}, "Whether to rescan the blockchain for missing transactions or not"},
         },
         RPCResult{
             RPCResult::Type::BOOL, "", "true if successful"
@@ -2874,7 +2874,7 @@ static RPCHelpMan loadwallet()
         "\napplied to the new wallet (eg, rescan, etc).\n",
         {
             {"filename", RPCArg::Type::STR, RPCArg::Optional::NO, "The wallet directory or .dat file."},
-            {"load_on_startup", RPCArg::Type::BOOL, /* default */ "null", "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
+            {"load_on_startup", RPCArg::Type::BOOL, RPCArg::Default{UniValue::VNULL}, "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -2922,7 +2922,7 @@ static RPCHelpMan setwalletflag()
         "\nChange the state of the given wallet flag for a wallet.\n",
         {
             {"flag", RPCArg::Type::STR, RPCArg::Optional::NO, "The name of the flag to change. Current available flags: " + flags},
-            {"value", RPCArg::Type::BOOL, /* default */ "true", "The new state."},
+            {"value", RPCArg::Type::BOOL, RPCArg::Default{true}, "The new state."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -2986,12 +2986,12 @@ static RPCHelpMan createwallet()
         "\nCreates and loads a new wallet.\n",
         {
             {"wallet_name", RPCArg::Type::STR, RPCArg::Optional::NO, "The name for the new wallet. If this is a path, the wallet will be created at the path location."},
-            {"disable_private_keys", RPCArg::Type::BOOL, /* default */ "false", "Disable the possibility of private keys (only watchonlys are possible in this mode)."},
-            {"blank", RPCArg::Type::BOOL, /* default */ "false", "Create a blank wallet. A blank wallet has no keys or HD seed. One can be set using upgradetohd (by mnemonic) or sethdseed (WIF private key)."},
+            {"disable_private_keys", RPCArg::Type::BOOL, RPCArg::Default{false}, "Disable the possibility of private keys (only watchonlys are possible in this mode)."},
+            {"blank", RPCArg::Type::BOOL, RPCArg::Default{false}, "Create a blank wallet. A blank wallet has no keys or HD seed. One can be set using upgradetohd (by mnemonic) or sethdseed (WIF private key)."},
             {"passphrase", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Encrypt the wallet with this passphrase."},
-            {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "false", "Keep track of coin reuse, and treat dirty and clean coins differently with privacy considerations in mind."},
-            {"descriptors", RPCArg::Type::BOOL, /* default */ "true", "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation. This feature is well-tested but still considered experimental."},
-            {"load_on_startup", RPCArg::Type::BOOL, /* default */ "null", "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
+            {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{false}, "Keep track of coin reuse, and treat dirty and clean coins differently with privacy considerations in mind."},
+            {"descriptors", RPCArg::Type::BOOL, RPCArg::Default{true}, "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation. This feature is well-tested but still considered experimental."},
+            {"load_on_startup", RPCArg::Type::BOOL, RPCArg::Default{UniValue::VNULL}, "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -3127,8 +3127,8 @@ static RPCHelpMan unloadwallet()
         "Unloads the wallet referenced by the request endpoint otherwise unloads the wallet specified in the argument.\n"
         "Specifying the wallet name on a wallet endpoint is invalid.",
         {
-            {"wallet_name", RPCArg::Type::STR, /* default */ "the wallet name from the RPC endpoint", "The name of the wallet to unload. If provided both here and in the RPC endpoint, the two must be identical."},
-            {"load_on_startup", RPCArg::Type::BOOL, /* default */ "null", "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
+            {"wallet_name", RPCArg::Type::STR, RPCArg::DefaultHint{"the wallet name from the RPC endpoint"}, "The name of the wallet to unload. If provided both here and in the RPC endpoint, the two must be identical."},
+            {"load_on_startup", RPCArg::Type::BOOL, RPCArg::Default{UniValue::VNULL}, "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
         },
         RPCResult{RPCResult::Type::OBJ, "", "", {
             {RPCResult::Type::STR, "warning", "Warning message if wallet was not unloaded cleanly."},
@@ -3178,22 +3178,22 @@ static RPCHelpMan listunspent()
         "with between minconf and maxconf (inclusive) confirmations.\n"
         "Optionally filter to only include txouts paid to specified addresses.\n",
         {
-            {"minconf", RPCArg::Type::NUM, /* default */ "1", "The minimum confirmations to filter"},
-            {"maxconf", RPCArg::Type::NUM, /* default */ "9999999", "The maximum confirmations to filter"},
-            {"addresses", RPCArg::Type::ARR, /* default */ "empty array", "The Dash addresses to filter",
+            {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "The minimum confirmations to filter"},
+            {"maxconf", RPCArg::Type::NUM, RPCArg::Default{9999999}, "The maximum confirmations to filter"},
+            {"addresses", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "The Dash addresses to filter",
                 {
                     {"address", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Dash address"},
                 },
             },
-            {"include_unsafe", RPCArg::Type::BOOL, /* default */ "true", "Include outputs that are not safe to spend\n"
+            {"include_unsafe", RPCArg::Type::BOOL, RPCArg::Default{true}, "Include outputs that are not safe to spend\n"
                 "See description of \"safe\" attribute below."},
             {"query_options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "JSON with query options",
                 {
-                    {"minimumAmount", RPCArg::Type::AMOUNT, /* default */ "0", "Minimum value of each UTXO in " + CURRENCY_UNIT + ""},
-                    {"maximumAmount", RPCArg::Type::AMOUNT, /* default */ "unlimited", "Maximum value of each UTXO in " + CURRENCY_UNIT + ""},
-                    {"maximumCount", RPCArg::Type::NUM, /* default */ "unlimited", "Maximum number of UTXOs"},
-                    {"minimumSumAmount", RPCArg::Type::AMOUNT, /* default */ "unlimited", "Minimum sum value of all UTXOs in " + CURRENCY_UNIT + ""},
-                    {"coinType", RPCArg::Type::NUM, /* default */ "0", "Filter coinTypes as follows:\n"
+                    {"minimumAmount", RPCArg::Type::AMOUNT, RPCArg::Default{FormatMoney(0)}, "Minimum value of each UTXO in " + CURRENCY_UNIT + ""},
+                    {"maximumAmount", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"unlimited"}, "Maximum value of each UTXO in " + CURRENCY_UNIT + ""},
+                    {"maximumCount", RPCArg::Type::NUM, RPCArg::DefaultHint{"unlimited"}, "Maximum number of UTXOs"},
+                    {"minimumSumAmount", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"unlimited"}, "Minimum sum value of all UTXOs in " + CURRENCY_UNIT + ""},
+                    {"coinType", RPCArg::Type::NUM, RPCArg::Default{0}, "Filter coinTypes as follows:\n"
                         "0=ALL_COINS, 1=ONLY_FULLY_MIXED, 2=ONLY_READY_TO_MIX, 3=ONLY_NONDENOMINATED,\n"
                         "4=ONLY_MASTERNODE_COLLATERAL, 5=ONLY_COINJOIN_COLLATERAL" },
                 },
@@ -3528,18 +3528,18 @@ static RPCHelpMan fundrawtransaction()
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of the raw transaction"},
                     {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "for backward compatibility: passing in a true instead of an object will result in {\"includeWatching\":true}",
                         {
-                            {"add_inputs", RPCArg::Type::BOOL, /* default */ "true", "For a transaction with existing inputs, automatically include more if they are not enough."},
-                            {"include_unsafe", RPCArg::Type::BOOL, /* default */ "false", "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
+                            {"add_inputs", RPCArg::Type::BOOL, RPCArg::Default{true}, "For a transaction with existing inputs, automatically include more if they are not enough."},
+                            {"include_unsafe", RPCArg::Type::BOOL, RPCArg::Default{false}, "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
                                                           "Warning: the resulting transaction may become invalid if one of the unsafe inputs disappears.\n"
                                                           "If that happens, you will need to fund the transaction with different inputs and republish it."},
-                            {"changeAddress", RPCArg::Type::STR, /* default */ "pool address", "The Dash address to receive the change"},
-                            {"changePosition", RPCArg::Type::NUM, /* default */ "random", "The index of the change output"},
-                            {"includeWatching", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Also select inputs which are watch only.\n"
+                            {"changeAddress", RPCArg::Type::STR, RPCArg::DefaultHint{"pool address"}, "The Dash address to receive the change"},
+                            {"changePosition", RPCArg::Type::NUM, RPCArg::DefaultHint{"random"}, "The index of the change output"},
+                            {"includeWatching", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Also select inputs which are watch only.\n"
                                                           "Only solvable inputs can be used. Watch-only destinations are solvable if the public key and/or output script was imported,\n"
                                                           "e.g. with 'importpubkey' or 'importmulti' with the 'pubkeys' or 'desc' field."},
-                            {"lockUnspents", RPCArg::Type::BOOL, /* default */ "false", "Lock selected unspent outputs"},
-                            {"feeRate", RPCArg::Type::AMOUNT, /* default */ "not set: makes wallet determine the fee", "Set a specific fee rate in " + CURRENCY_UNIT + "/kB"},
-                            {"subtractFeeFromOutputs", RPCArg::Type::ARR, /* default */ "empty array", "The integers.\n"
+                            {"lockUnspents", RPCArg::Type::BOOL, RPCArg::Default{false}, "Lock selected unspent outputs"},
+                            {"feeRate", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"not set: makes wallet determine the fee"}, "Set a specific fee rate in " + CURRENCY_UNIT + "/kB"},
+                            {"subtractFeeFromOutputs", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "The integers.\n"
                                 "The fee will be equally deducted from the amount of each specified output.\n"
                                 "Those recipients will receive less Dash than you enter in their corresponding amount field.\n"
                                 "If no outputs are specified here, the sender pays the fee.",
@@ -3547,8 +3547,8 @@ static RPCHelpMan fundrawtransaction()
                                     {"vout_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "The zero-based output index, before a change output is added."},
                                 },
                             },
-                            {"conf_target", RPCArg::Type::NUM, /* default */ "wallet default", "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
-                            {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+                            {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet default"}, "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
+                            {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
                             "       \"" + FeeModes("\"\n\"") + "\""},
                         },
                         "options"},
@@ -3623,7 +3623,7 @@ RPCHelpMan signrawtransactionwithwallet()
                     },
                 },
             },
-            {"sighashtype", RPCArg::Type::STR, /* default */ "ALL", "The signature hash type. Must be one of\n"
+            {"sighashtype", RPCArg::Type::STR, RPCArg::Default{"ALL"}, "The signature hash type. Must be one of\n"
     "       \"ALL\"\n"
     "       \"NONE\"\n"
     "       \"SINGLE\"\n"
@@ -3699,7 +3699,7 @@ static RPCHelpMan rescanblockchain()
         "\nRescan the local blockchain for wallet related transactions.\n"
         "Note: Use \"getwalletinfo\" to query the scanning progress.\n",
         {
-            {"start_height", RPCArg::Type::NUM, /* default */ "0", "block height where the rescan should start"},
+            {"start_height", RPCArg::Type::NUM, RPCArg::Default{0}, "block height where the rescan should start"},
             {"stop_height", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "the last block height that should be scanned. If none is provided it will rescan up to the tip at return time of this call."},
         },
         RPCResult{
@@ -3784,7 +3784,7 @@ static RPCHelpMan wipewallettxes()
         "\nWipe wallet transactions.\n"
         "Note: Use \"rescanblockchain\" to initiate the scanning progress and recover wallet transactions.\n",
         {
-            {"keep_confirmed", RPCArg::Type::BOOL, /* default */ "false", "Do not wipe confirmed transactions"},
+            {"keep_confirmed", RPCArg::Type::BOOL, RPCArg::Default{false}, "Do not wipe confirmed transactions"},
         },
         RPCResult{RPCResult::Type::NONE, "", ""},
         RPCExamples{
@@ -4191,35 +4191,35 @@ static RPCHelpMan send()
                     },
                 },
             },
-            {"conf_target", RPCArg::Type::NUM, /* default */ "wallet default", "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
-            {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+            {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet default"}, "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
+            {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
                         "       \"" + FeeModes("\"\n\"") + "\""},
             {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                 {
-                    {"add_inputs", RPCArg::Type::BOOL, /* default */ "false", "If inputs are specified, automatically include more if they are not enough."},
-                    {"include_unsafe", RPCArg::Type::BOOL, /* default */ "false", "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
+                    {"add_inputs", RPCArg::Type::BOOL, RPCArg::Default{false}, "If inputs are specified, automatically include more if they are not enough."},
+                    {"include_unsafe", RPCArg::Type::BOOL, RPCArg::Default{false}, "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
                                                           "Warning: the resulting transaction may become invalid if one of the unsafe inputs disappears.\n"
                                                           "If that happens, you will need to fund the transaction with different inputs and republish it."},
-                    {"add_to_wallet", RPCArg::Type::BOOL, /* default */ "true", "When false, returns a serialized transaction which will not be added to the wallet or broadcast"},
-                    {"change_address", RPCArg::Type::STR_HEX, /* default */ "pool address", "The Dash address to receive the change"},
-                    {"change_position", RPCArg::Type::NUM, /* default */ "random", "The index of the change output"},
-                    {"conf_target", RPCArg::Type::NUM, /* default */ "wallet default", "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
-                    {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+                    {"add_to_wallet", RPCArg::Type::BOOL, RPCArg::Default{true}, "When false, returns a serialized transaction which will not be added to the wallet or broadcast"},
+                    {"change_address", RPCArg::Type::STR_HEX, RPCArg::DefaultHint{"pool address"}, "The Dash address to receive the change"},
+                    {"change_position", RPCArg::Type::NUM, RPCArg::DefaultHint{"random"}, "The index of the change output"},
+                    {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"wallet default"}, "Confirmation target (in blocks), or fee rate (for " + CURRENCY_UNIT + "/kB or " + CURRENCY_ATOM + "/B estimate modes)"},
+                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
             "       \"" + FeeModes("\"\n\"") + "\""},
-                    {"include_watching", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Also select inputs which are watch only.\n"
+                    {"include_watching", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Also select inputs which are watch only.\n"
                                           "Only solvable inputs can be used. Watch-only destinations are solvable if the public key and/or output script was imported,\n"
                                           "e.g. with 'importpubkey' or 'importmulti' with the 'pubkeys' or 'desc' field."},
-                    {"inputs", RPCArg::Type::ARR, /* default */ "empty array", "Specify inputs instead of adding them automatically. A JSON array of JSON objects",
+                    {"inputs", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "Specify inputs instead of adding them automatically. A JSON array of JSON objects",
                         {
                             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
                             {"sequence", RPCArg::Type::NUM, RPCArg::Optional::NO, "The sequence number"},
                         },
                     },
-                    {"locktime", RPCArg::Type::NUM, /* default */ "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
-                    {"lock_unspents", RPCArg::Type::BOOL, /* default */ "false", "Lock selected unspent outputs"},
-                    {"psbt", RPCArg::Type::BOOL,  /* default */ "automatic", "Always return a PSBT, implies add_to_wallet=false."},
-                    {"subtract_fee_from_outputs", RPCArg::Type::ARR, /* default */ "empty array", "A JSON array of integers.\n"
+                    {"locktime", RPCArg::Type::NUM, RPCArg::Default{0}, "Raw locktime. Non-0 value also locktime-activates inputs"},
+                    {"lock_unspents", RPCArg::Type::BOOL, RPCArg::Default{false}, "Lock selected unspent outputs"},
+                    {"psbt", RPCArg::Type::BOOL,  RPCArg::DefaultHint{"automatic"}, "Always return a PSBT, implies add_to_wallet=false."},
+                    {"subtract_fee_from_outputs", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "A JSON array of integers.\n"
                     "The fee will be equally deducted from the amount of each specified output.\n"
                     "Those recipients will receive less funds than you enter in their corresponding amount field.\n"
                     "If no outputs are specified here, the sender pays the fee.",
@@ -4350,10 +4350,10 @@ static RPCHelpMan sethdseed()
                 "\nNote that you will need to MAKE A NEW BACKUP of your wallet after setting the HD wallet seed." +
         HELP_REQUIRING_PASSPHRASE,
                 {
-                    {"newkeypool", RPCArg::Type::BOOL, /* default */ "true", "Whether to flush old unused addresses, including change addresses, from the keypool and regenerate it.\n"
+                    {"newkeypool", RPCArg::Type::BOOL, RPCArg::Default{true}, "Whether to flush old unused addresses, including change addresses, from the keypool and regenerate it.\n"
                                          "If true, the next address from getnewaddress and change address from getrawchangeaddress will be from this new seed.\n"
                                          "If false, addresses from the existing keypool will be used until it has been depleted."},
-                    {"seed", RPCArg::Type::STR, /* default */ "random seed", "The WIF private key to use as the new HD seed.\n"
+                    {"seed", RPCArg::Type::STR, RPCArg::DefaultHint{"random seed"}, "The WIF private key to use as the new HD seed.\n"
                                          "The seed value can be retrieved using the dumpwallet command. It is the private key marked hdseed=1"},
                 },
                 RPCResult{RPCResult::Type::NONE, "", ""},
@@ -4428,15 +4428,15 @@ RPCHelpMan walletprocesspsbt()
                 HELP_REQUIRING_PASSPHRASE,
         {
             {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction base64 string"},
-            {"sign", RPCArg::Type::BOOL, /* default */ "true", "Also sign the transaction when updating"},
-            {"sighashtype", RPCArg::Type::STR, /* default */ "ALL", "The signature hash type to sign with if not specified by the PSBT. Must be one of\n"
+            {"sign", RPCArg::Type::BOOL, RPCArg::Default{true}, "Also sign the transaction when updating"},
+            {"sighashtype", RPCArg::Type::STR, RPCArg::Default{"ALL"}, "The signature hash type to sign with if not specified by the PSBT. Must be one of\n"
     "       \"ALL\"\n"
     "       \"NONE\"\n"
     "       \"SINGLE\"\n"
     "       \"ALL|ANYONECANPAY\"\n"
     "       \"NONE|ANYONECANPAY\"\n"
     "       \"SINGLE|ANYONECANPAY\""},
-            {"bip32derivs", RPCArg::Type::BOOL, /* default */ "true", "Include BIP 32 derivation paths for public keys if we know them"},
+            {"bip32derivs", RPCArg::Type::BOOL, RPCArg::Default{true}, "Include BIP 32 derivation paths for public keys if we know them"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -4506,7 +4506,7 @@ static RPCHelpMan walletcreatefundedpsbt()
                         {
                             {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                             {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
-                            {"sequence", RPCArg::Type::NUM, /* default */ "depends on the value of the 'locktime' argument", "The sequence number"},
+                            {"sequence", RPCArg::Type::NUM, RPCArg::DefaultHint{"depends on the value of the 'locktime' argument"}, "The sequence number"},
                         },
                     },
                 },
@@ -4528,19 +4528,19 @@ static RPCHelpMan walletcreatefundedpsbt()
                     },
                 },
             },
-            {"locktime", RPCArg::Type::NUM, /* default */ "0", "Raw locktime. Non-0 value also locktime-activates inputs"},
+            {"locktime", RPCArg::Type::NUM, RPCArg::Default{0}, "Raw locktime. Non-0 value also locktime-activates inputs"},
             {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                 {
-                    {"add_inputs", RPCArg::Type::BOOL, /* default */ "false", "If inputs are specified, automatically include more if they are not enough."},
-                    {"include_unsafe", RPCArg::Type::BOOL, /* default */ "false", "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
+                    {"add_inputs", RPCArg::Type::BOOL, RPCArg::Default{false}, "If inputs are specified, automatically include more if they are not enough."},
+                    {"include_unsafe", RPCArg::Type::BOOL, RPCArg::Default{false}, "Include inputs that are not safe to spend (unconfirmed transactions from outside keys and unconfirmed replacement transactions).\n"
                                                     "Warning: the resulting transaction may become invalid if one of the unsafe inputs disappears.\n"
                                                     "If that happens, you will need to fund the transaction with different inputs and republish it."},
-                    {"changeAddress", RPCArg::Type::STR_HEX, /* default */ "pool address", "The Dash address to receive the change"},
-                    {"changePosition", RPCArg::Type::NUM, /* default */ "random", "The index of the change output"},
-                    {"includeWatching", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Also select inputs which are watch only"},
-                    {"lockUnspents", RPCArg::Type::BOOL, /* default */ "false", "Lock selected unspent outputs"},
-                    {"feeRate", RPCArg::Type::AMOUNT, /* default */ "not set: makes wallet determine the fee", "Set a specific fee rate in " + CURRENCY_UNIT + "/kB"},
-                    {"subtractFeeFromOutputs", RPCArg::Type::ARR, /* default */ "empty array", "The outputs to subtract the fee from.\n"
+                    {"changeAddress", RPCArg::Type::STR_HEX, RPCArg::DefaultHint{"pool address"}, "The Dash address to receive the change"},
+                    {"changePosition", RPCArg::Type::NUM, RPCArg::DefaultHint{"random"}, "The index of the change output"},
+                    {"includeWatching", RPCArg::Type::BOOL, RPCArg::DefaultHint{"true for watch-only wallets, otherwise false"}, "Also select inputs which are watch only"},
+                    {"lockUnspents", RPCArg::Type::BOOL, RPCArg::Default{false}, "Lock selected unspent outputs"},
+                    {"feeRate", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"not set: makes wallet determine the fee"}, "Set a specific fee rate in " + CURRENCY_UNIT + "/kB"},
+                    {"subtractFeeFromOutputs", RPCArg::Type::ARR, RPCArg::Default{UniValue::VARR}, "The outputs to subtract the fee from.\n"
                         "The fee will be equally deducted from the amount of each specified output.\n"
                         "Those recipients will receive less Dash than you enter in their corresponding amount field.\n"
                         "If no outputs are specified here, the sender pays the fee.",
@@ -4548,12 +4548,12 @@ static RPCHelpMan walletcreatefundedpsbt()
                             {"vout_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "The zero-based output index, before a change output is added."},
                         },
                     },
-                    {"conf_target", RPCArg::Type::NUM, /* default */ "Fallback to wallet's confirmation target", "Confirmation target (in blocks)"},
-                    {"estimate_mode", RPCArg::Type::STR, /* default */ "unset", std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
+                    {"conf_target", RPCArg::Type::NUM, RPCArg::DefaultHint{"Fallback to wallet's confirmation target"}, "Confirmation target (in blocks)"},
+                    {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, std::string() + "The fee estimate mode, must be one of (case insensitive):\n"
                     "         \"" + FeeModes("\"\n\"") + "\""},
                 },
                 "options"},
-            {"bip32derivs", RPCArg::Type::BOOL, /* default */ "true", "Include BIP 32 derivation paths for public keys if we know them"},
+            {"bip32derivs", RPCArg::Type::BOOL, RPCArg::Default{true}, "Include BIP 32 derivation paths for public keys if we know them"},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -4625,7 +4625,7 @@ static RPCHelpMan upgradewallet()
         "\nUpgrade the wallet. Upgrades to the latest version if no version number is specified.\n"
         "New keys may be generated and a new wallet backup will need to be made.",
         {
-            {"version", RPCArg::Type::NUM, /* default */ strprintf("%d", FEATURE_LATEST), "The version number to upgrade to. Default is the latest wallet version."}
+            {"version", RPCArg::Type::NUM, RPCArg::Default{FEATURE_LATEST}, "The version number to upgrade to. Default is the latest wallet version."}
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",