diff --git a/libtransmission/serializer.h b/libtransmission/serializer.h
index df10408b0..019aa0731 100644
--- a/libtransmission/serializer.h
+++ b/libtransmission/serializer.h
@@ -137,7 +137,7 @@ public:
             return detail::from_array(src);
         }
 
-        fmt::print(stderr, "ERROR: No serializer registered for type '{}'\\n", typeid(T).name());
+        fmt::print(stderr, "ERROR: No serializer registered for type '{}'\n", typeid(T).name());
         return {};
     }
 
@@ -166,6 +166,7 @@ public:
             return detail::to_array(src, ptgt);
         }
 
+        fmt::print(stderr, "ERROR: No deserializer registered for type '{}'\n", typeid(T).name());
         return false;
     }
 
diff --git a/qt/Session.cc b/qt/Session.cc
index e33a123da..cba0b5887 100644
--- a/qt/Session.cc
+++ b/qt/Session.cc
@@ -22,6 +22,8 @@
 #include <QTextStream>
 #include <QtDebug>
 
+#include <small/vector.hpp>
+
 #include <libtransmission/transmission.h>
 
 #include <libtransmission/quark.h>
@@ -44,6 +46,7 @@ using namespace std::literals;
 using ::trqt::variant_helpers::dictAdd;
 using ::trqt::variant_helpers::dictFind;
 using ::trqt::variant_helpers::getValue;
+using ::trqt::variant_helpers::to_variant;
 
 /***
 ****
@@ -385,6 +388,18 @@ void Session::start()
 
 // ---
 
+void Session::addOptionalIds(tr_variant::Map& params, torrent_ids_t const& torrent_ids) const
+{
+    if (&torrent_ids == &RecentlyActiveIDs)
+    {
+        params.try_emplace(TR_KEY_ids, tr_variant::unmanaged_string(TR_KEY_recently_active));
+    }
+    else if (!std::empty(torrent_ids))
+    {
+        params.try_emplace(TR_KEY_ids, to_variant(torrent_ids));
+    }
+}
+
 void Session::addOptionalIds(tr_variant* args_dict, torrent_ids_t const& torrent_ids) const
 {
     if (&torrent_ids == &RecentlyActiveIDs)
@@ -511,149 +526,177 @@ void Session::torrentRenamePath(torrent_ids_t const& torrent_ids, QString const&
     q->run();
 }
 
-std::set<std::string_view> const& Session::getKeyNames(TorrentProperties props)
+namespace
 {
-    std::set<std::string_view>& names = names_[props];
+using TorrentProperties = Session::TorrentProperties;
 
-    if (names.empty())
+[[nodiscard]] small::max_size_vector<tr_quark, 64U> getKeys(TorrentProperties const props)
+{
+    // IMPORTANT when changing these key sets:
+    // 1. `TR_KEY_id` must be in every set
+    // 2. When changing `MainInfo` or `MainStats`, update their union in `MainAll`
+
+    // clang-format off: one line per key
+    switch (props)
     {
-        // unchanging fields needed by the main window
-        static auto constexpr MainInfoKeys = std::array<tr_quark, 9>{
-            TR_KEY_added_date, //
-            TR_KEY_download_dir, //
-            TR_KEY_file_count, //
-            TR_KEY_hash_string, //
-            TR_KEY_labels, //
-            TR_KEY_name, //
-            TR_KEY_primary_mime_type, //
-            TR_KEY_total_size, //
-            TR_KEY_trackers, //
-        };
-
-        // changing fields needed by the main window
-        static auto constexpr MainStatKeys = std::array<tr_quark, 25>{
-            TR_KEY_downloaded_ever,
-            TR_KEY_edit_date,
-            TR_KEY_error,
-            TR_KEY_error_string,
-            TR_KEY_eta,
-            TR_KEY_have_unchecked,
-            TR_KEY_have_valid,
-            TR_KEY_is_finished,
-            TR_KEY_left_until_done,
-            TR_KEY_manual_announce_time,
-            TR_KEY_metadata_percent_complete,
-            TR_KEY_peers_connected,
-            TR_KEY_peers_getting_from_us,
-            TR_KEY_peers_sending_to_us,
-            TR_KEY_percent_done,
-            TR_KEY_queue_position,
-            TR_KEY_rate_download,
-            TR_KEY_rate_upload,
-            TR_KEY_recheck_progress,
-            TR_KEY_seed_ratio_limit,
-            TR_KEY_seed_ratio_mode,
-            TR_KEY_size_when_done,
-            TR_KEY_status,
-            TR_KEY_uploaded_ever,
-            TR_KEY_webseeds_sending_to_us,
-        };
-
         // unchanging fields needed by the details dialog
-        static auto constexpr DetailInfoKeys = std::array<tr_quark, 10>{
-            TR_KEY_comment, //
-            TR_KEY_creator, //
-            TR_KEY_date_created, //
-            TR_KEY_files, //
-            TR_KEY_is_private, //
-            TR_KEY_labels, //
-            TR_KEY_piece_count, //
-            TR_KEY_piece_size, //
-            TR_KEY_tracker_list, //
-            TR_KEY_trackers, //
-        };
+        case TorrentProperties::DetailInfo:
+            return {
+                TR_KEY_comment,
+                TR_KEY_creator,
+                TR_KEY_date_created,
+                TR_KEY_files,
+                TR_KEY_id,
+                TR_KEY_is_private,
+                TR_KEY_labels,
+                TR_KEY_piece_count,
+                TR_KEY_piece_size,
+                TR_KEY_tracker_list,
+                TR_KEY_trackers,
+            };
 
         // changing fields needed by the details dialog
-        static auto constexpr DetailStatKeys = std::array<tr_quark, 18>{
-            TR_KEY_activity_date, //
-            TR_KEY_bandwidth_priority, //
-            TR_KEY_corrupt_ever, //
-            TR_KEY_desired_available, //
-            TR_KEY_downloaded_ever, //
-            TR_KEY_download_limit, //
-            TR_KEY_download_limited, //
-            TR_KEY_file_stats, //
-            TR_KEY_have_unchecked, //
-            TR_KEY_honors_session_limits, //
-            TR_KEY_peer_limit, //
-            TR_KEY_peers, //
-            TR_KEY_seed_idle_limit, //
-            TR_KEY_seed_idle_mode, //
-            TR_KEY_start_date, //
-            TR_KEY_tracker_stats, //
-            TR_KEY_upload_limit, //
-            TR_KEY_upload_limited, //
-        };
+        case TorrentProperties::DetailStat:
+            return {
+                TR_KEY_activity_date,
+                TR_KEY_bandwidth_priority,
+                TR_KEY_corrupt_ever,
+                TR_KEY_desired_available,
+                TR_KEY_download_limit,
+                TR_KEY_download_limited,
+                TR_KEY_downloaded_ever,
+                TR_KEY_file_stats,
+                TR_KEY_have_unchecked,
+                TR_KEY_honors_session_limits,
+                TR_KEY_id,
+                TR_KEY_peer_limit,
+                TR_KEY_peers,
+                TR_KEY_seed_idle_limit,
+                TR_KEY_seed_idle_mode,
+                TR_KEY_start_date,
+                TR_KEY_tracker_stats,
+                TR_KEY_upload_limit,
+                TR_KEY_upload_limited,
+            };
+
+        // union of MainInfoKeys + MainStatKeys
+        case TorrentProperties::MainAll:
+            return {
+                TR_KEY_added_date,
+                TR_KEY_download_dir,
+                TR_KEY_downloaded_ever,
+                TR_KEY_edit_date,
+                TR_KEY_error,
+                TR_KEY_error_string,
+                TR_KEY_eta,
+                TR_KEY_file_count,
+                TR_KEY_hash_string,
+                TR_KEY_have_unchecked,
+                TR_KEY_have_valid,
+                TR_KEY_id,
+                TR_KEY_is_finished,
+                TR_KEY_labels,
+                TR_KEY_left_until_done,
+                TR_KEY_manual_announce_time,
+                TR_KEY_metadata_percent_complete,
+                TR_KEY_name,
+                TR_KEY_peers_connected,
+                TR_KEY_peers_getting_from_us,
+                TR_KEY_peers_sending_to_us,
+                TR_KEY_percent_done,
+                TR_KEY_primary_mime_type,
+                TR_KEY_queue_position,
+                TR_KEY_rate_download,
+                TR_KEY_rate_upload,
+                TR_KEY_recheck_progress,
+                TR_KEY_seed_ratio_limit,
+                TR_KEY_seed_ratio_mode,
+                TR_KEY_size_when_done,
+                TR_KEY_status,
+                TR_KEY_total_size,
+                TR_KEY_trackers,
+                TR_KEY_uploaded_ever,
+                TR_KEY_webseeds_sending_to_us,
+            };
+
+        // unchanging fields needed by the main window
+        case TorrentProperties::MainInfo:
+            return {
+                TR_KEY_added_date,
+                TR_KEY_download_dir,
+                TR_KEY_file_count,
+                TR_KEY_hash_string,
+                TR_KEY_id,
+                TR_KEY_labels,
+                TR_KEY_name,
+                TR_KEY_primary_mime_type,
+                TR_KEY_total_size,
+                TR_KEY_trackers,
+            };
+
+        // changing fields needed by the main window
+        case TorrentProperties::MainStats:
+            return {
+                TR_KEY_downloaded_ever,
+                TR_KEY_edit_date,
+                TR_KEY_error,
+                TR_KEY_error_string,
+                TR_KEY_eta,
+                TR_KEY_have_unchecked,
+                TR_KEY_have_valid,
+                TR_KEY_id,
+                TR_KEY_is_finished,
+                TR_KEY_left_until_done,
+                TR_KEY_manual_announce_time,
+                TR_KEY_metadata_percent_complete,
+                TR_KEY_peers_connected,
+                TR_KEY_peers_getting_from_us,
+                TR_KEY_peers_sending_to_us,
+                TR_KEY_percent_done,
+                TR_KEY_queue_position,
+                TR_KEY_rate_download,
+                TR_KEY_rate_upload,
+                TR_KEY_recheck_progress,
+                TR_KEY_seed_ratio_limit,
+                TR_KEY_seed_ratio_mode,
+                TR_KEY_size_when_done,
+                TR_KEY_status,
+                TR_KEY_uploaded_ever,
+                TR_KEY_webseeds_sending_to_us,
+            };
 
         // keys needed after renaming a torrent
-        static auto constexpr RenameKeys = std::array<tr_quark, 3>{
-            TR_KEY_file_stats,
-            TR_KEY_files,
-            TR_KEY_name,
-        };
-
-        auto const append = [&names](tr_quark key)
-        {
-            names.emplace(tr_quark_get_string_view(key));
-        };
-
-        switch (props)
-        {
-        case TorrentProperties::DetailInfo:
-            std::for_each(DetailInfoKeys.begin(), DetailInfoKeys.end(), append);
-            break;
-
-        case TorrentProperties::DetailStat:
-            std::for_each(DetailStatKeys.begin(), DetailStatKeys.end(), append);
-            break;
-
-        case TorrentProperties::MainAll:
-            std::for_each(MainInfoKeys.begin(), MainInfoKeys.end(), append);
-            std::for_each(MainStatKeys.begin(), MainStatKeys.end(), append);
-            break;
-
-        case TorrentProperties::MainInfo:
-            std::for_each(MainInfoKeys.begin(), MainInfoKeys.end(), append);
-            break;
-
-        case TorrentProperties::MainStats:
-            std::for_each(MainStatKeys.begin(), MainStatKeys.end(), append);
-            break;
-
         case TorrentProperties::Rename:
-            std::for_each(RenameKeys.begin(), RenameKeys.end(), append);
-            break;
-        }
-
-        // must be in every torrent req
-        append(TR_KEY_id);
+            return {
+                TR_KEY_file_stats,
+                TR_KEY_files,
+                TR_KEY_id,
+                TR_KEY_name,
+            };
     }
-
-    return names;
+    // clang-format on
 }
+} // namespace
 
-void Session::refreshTorrents(torrent_ids_t const& torrent_ids, TorrentProperties props)
+void Session::refreshTorrents(torrent_ids_t const& torrent_ids, TorrentProperties const props)
 {
-    auto constexpr Table = std::string_view{ "table" };
+    auto fields = tr_variant::Vector{};
+    auto const keys = getKeys(props);
+    fields.reserve(std::size(keys));
+    std::transform(
+        std::begin(keys),
+        std::end(keys),
+        std::back_inserter(fields),
+        [](auto key) { return tr_variant::unmanaged_string(key); });
 
-    tr_variant args;
-    tr_variantInitDict(&args, 3);
-    dictAdd(&args, TR_KEY_format, Table);
-    dictAdd(&args, TR_KEY_fields, getKeyNames(props));
-    addOptionalIds(&args, torrent_ids);
+    auto map = tr_variant::Map{ 3U };
+    map.try_emplace(TR_KEY_format, tr_variant::unmanaged_string("table"sv));
+    map.try_emplace(TR_KEY_fields, std::move(fields));
+    addOptionalIds(map, torrent_ids);
 
     auto* q = new RpcQueue{};
 
+    auto args = tr_variant{ std::move(map) };
     q->add([this, &args]() { return exec(TR_KEY_torrent_get, &args); });
 
     bool const all_torrents = std::empty(torrent_ids);
diff --git a/qt/Session.h b/qt/Session.h
index 7753741bf..daf171f20 100644
--- a/qt/Session.h
+++ b/qt/Session.h
@@ -9,7 +9,6 @@
 #include <cstdint> // int64_t
 #include <map>
 #include <optional>
-#include <set>
 #include <string_view>
 #include <vector>
 
@@ -135,26 +134,6 @@ public:
         Rename
     };
 
-    void addKeyName(TorrentProperties props, tr_quark const key)
-    {
-        // populate names cache with default values
-        if (names_[props].empty())
-        {
-            getKeyNames(props);
-        }
-
-        names_[props].emplace(tr_quark_get_string_view(key));
-    }
-
-    void removeKeyName(TorrentProperties props, tr_quark const key)
-    {
-        // do not remove id because it must be in every torrent req
-        if (key != TR_KEY_id)
-        {
-            names_[props].erase(tr_quark_get_string_view(key));
-        }
-    }
-
 public slots:
     void addTorrent(AddData add_me);
     void launchWebInterface() const;
@@ -195,17 +174,15 @@ private:
     void pumpRequests();
     void sendTorrentRequest(tr_quark method, torrent_ids_t const& torrent_ids);
     void refreshTorrents(torrent_ids_t const& ids, TorrentProperties props);
-    std::set<std::string_view> const& getKeyNames(TorrentProperties props);
 
     static void updateStats(tr_variant* args_dict, tr_session_stats* stats);
 
+    void addOptionalIds(tr_variant::Map& params, torrent_ids_t const& torrent_ids) const;
     void addOptionalIds(tr_variant* args_dict, torrent_ids_t const& torrent_ids) const;
 
     QString const config_dir_;
     Prefs& prefs_;
 
-    std::map<TorrentProperties, std::set<std::string_view>> names_;
-
     int64_t blocklist_size_ = -1;
     std::array<bool, NUM_PORT_TEST_IP_PROTOCOL> port_test_pending_ = {};
     tr_session* session_ = {};
diff --git a/qt/VariantHelpers.cc b/qt/VariantHelpers.cc
index 73afc95cd..f738a37e3 100644
--- a/qt/VariantHelpers.cc
+++ b/qt/VariantHelpers.cc
@@ -8,10 +8,13 @@
 #include <cmath>
 #include <cstdint>
 #include <limits>
+#include <mutex>
 #include <string_view>
 
 #include <QUrl>
 
+#include <libtransmission/serializer.h>
+
 #include "Application.h" // qApp
 #include "Speed.h"
 #include "Torrent.h"
@@ -228,4 +231,40 @@ void variantInit(tr_variant* init_me, std::string_view value)
     *init_me = value;
 }
 
+namespace
+{
+bool to_int(tr_variant const& src, int* tgt)
+{
+    if (auto const val = src.value_if<int64_t>())
+    {
+        if (*val < std::numeric_limits<int>::min() || *val > std::numeric_limits<int>::max())
+        {
+            return false;
+        }
+
+        *tgt = static_cast<int>(*val);
+        return true;
+    }
+
+    return false;
+}
+
+tr_variant from_int(int const& val)
+{
+    return static_cast<int64_t>(val);
+}
+} // namespace
+
+void register_qt_converters()
+{
+    static auto once = std::once_flag{};
+    std::call_once(
+        once,
+        []
+        {
+            using namespace libtransmission::serializer;
+            Converters::add(to_int, from_int);
+        });
+}
+
 } // namespace trqt::variant_helpers
diff --git a/qt/VariantHelpers.h b/qt/VariantHelpers.h
index ea54ae9b9..932916499 100644
--- a/qt/VariantHelpers.h
+++ b/qt/VariantHelpers.h
@@ -14,6 +14,7 @@
 
 #include <QString>
 
+#include <libtransmission/serializer.h>
 #include <libtransmission/variant.h>
 
 class QByteArray;
@@ -26,6 +27,13 @@ struct TrackerStat;
 
 namespace trqt::variant_helpers
 {
+void register_qt_converters();
+
+template<typename T>
+[[nodiscard]] tr_variant to_variant(T const& val)
+{
+    return libtransmission::serializer::Converters::serialize(val);
+}
 
 template<typename T, typename std::enable_if_t<std::is_same_v<T, bool>>* = nullptr>
 auto getValue(tr_variant const* variant)
diff --git a/qt/main.cc b/qt/main.cc
index c98210634..413193485 100644
--- a/qt/main.cc
+++ b/qt/main.cc
@@ -18,6 +18,7 @@
 #include "Application.h"
 #include "InteropHelper.h"
 #include "Prefs.h"
+#include "VariantHelpers.h"
 
 using namespace std::string_view_literals;
 
@@ -99,8 +100,8 @@ bool tryDelegate(QStringList const& filenames)
 int tr_main(int argc, char** argv)
 {
     tr_lib_init();
-
     tr_locale_set_global("");
+    trqt::variant_helpers::register_qt_converters();
 
     // parse the command-line arguments
     bool minimized = false;