diff --git a/src/Error.cpp b/src/Error.cpp
index b78947f..a7111fe 100644
--- a/src/Error.cpp
+++ b/src/Error.cpp
@@ -6,6 +6,11 @@
 
 using namespace ts;
 
+#define str(x) #x
+
+#define define_error_description(type, description) \
+{ error::type, str(type), description }
+
 const std::vector<ErrorType> ts::avariableErrors = {
         {0x0000, "ok"                                   , "ok"                                                         },
         {0x0001, "undefined"                            , "undefined error"                                            },
@@ -95,6 +100,8 @@ const std::vector<ErrorType> ts::avariableErrors = {
         {0x0605, "parameter_invalid_size"               , "invalid parameter size"                                     },
         {0x0606, "parameter_missing"                    , "missing required parameter"                                 },
         {0x0607, "parameter_checksum"                   , "invalid checksum"                                           },
+        define_error_description(parameter_constraint_violation, "parameter does not fits its constraint"),
+        /* example: all name= parameter in a bulk must start with /icon_ */
 
         {0x0700, "vs_critical"                          , "virtual server got a critical error"                        },
         {0x0701, "connection_lost"                      , "Connection lost"                                            },
@@ -134,7 +141,8 @@ const std::vector<ErrorType> ts::avariableErrors = {
         {0x0815, "file_transfer_client_quota_exceeded"  , "file transfer client quota exceeded"                        },
         {0x0816, "file_transfer_reset"                  , "file transfer reset"                                        },
         {0x0817, "file_transfer_limit_reached"          , "file transfer limit reached"                                },
-
+        define_error_description(file_api_timeout, "the file API call has been timed out"),
+        define_error_description(file_virtual_server_not_registered, "the file server does not know our virtual server"),
 
         {0x0A08, "server_insufficeient_permissions"     , "insufficient client permissions"                            },
 
diff --git a/src/Error.h b/src/Error.h
index 301472d..c98a7a2 100644
--- a/src/Error.h
+++ b/src/Error.h
@@ -105,6 +105,8 @@ namespace ts {
             parameter_invalid_size = 0x605,
             parameter_missing = 0x606,
             parameter_checksum = 0x607,
+            parameter_constraint_violation = 0x6010,
+
             vs_critical = 0x700,
             connection_lost = 0x701,
             not_connected = 0x702,
@@ -118,6 +120,7 @@ namespace ts {
             serverlibrary_not_initialised = 0x70a,
             whisper_too_many_targets = 0x70b,
             whisper_no_targets = 0x70c,
+
             file_invalid_name = 0x800,
             file_invalid_permissions = 0x801,
             file_already_exists = 0x802,
@@ -142,6 +145,12 @@ namespace ts {
             file_transfer_client_quota_exceeded = 0x815,
             file_transfer_reset = 0x816,
             file_transfer_limit_reached = 0x817,
+
+            file_api_timeout = 0x820,
+            file_virtual_server_not_registered = 0x821,
+            file_server_transfer_limit_reached = 0x822,
+            file_client_transfer_limit_reached = 0x823,
+
             server_insufficeient_permissions = 0xa08,
             accounting_slot_limit_reached = 0xb01,
             server_connect_banned = 0xd01,
@@ -380,6 +389,14 @@ namespace ts {
                     result.release_data();
             }
 
+            inline size_t length() const {
+                return this->results.size();
+            }
+
+            inline const ts::command_result& response(size_t index) const {
+                return this->results[index];
+            }
+
             inline void reserve(size_t length) {
                 this->results.reserve(length);
             }
@@ -388,6 +405,10 @@ namespace ts {
                 this->results.push_back(std::forward<ts::command_result>(result));
             }
 
+            inline void set_result(size_t index, ts::command_result&& result) {
+                this->results[index].reset(std::forward<ts::command_result>(result));
+            }
+
             inline void emplace_result(permission::PermissionType permission) {
                 this->results.emplace_back(permission);
             }
diff --git a/src/License.h b/src/License.h
index 70b1167..747e7d7 100644
--- a/src/License.h
+++ b/src/License.h
@@ -34,6 +34,8 @@ namespace license {
                     return "MyTsIdSign";
                 case LicenseType::EPHEMERAL:
                     return "Ephemeral";
+                case LicenseType::TOKEN:
+                    return "Token";
                 default:
                     return "Unknown";
             }
diff --git a/src/Properties.h b/src/Properties.h
index 85052b7..9072e70 100644
--- a/src/Properties.h
+++ b/src/Properties.h
@@ -767,7 +767,7 @@ namespace ts {
             [[nodiscard]] operator T(){ return this->as<T>(); }
 
             template <typename T>
-            [[nodiscard]] T as_save() const {
+            [[nodiscard]] T as_save(const std::function<T()> defaultValue = []{ return T{}; }) const {
                 try {
                     std::lock_guard lock(this->data_ptr->value_lock);
                     if(this->data_ptr->casted_value.type() == typeid(T))
@@ -776,7 +776,7 @@ namespace ts {
                     this->data_ptr->casted_value = ts::converter<T>::from_string_view(this->data_ptr->value);
                     return std::any_cast<T>(this->data_ptr->casted_value);
                 } catch(std::exception&) {
-                    return T{};
+                    return defaultValue();
                 }
             }
 
diff --git a/src/protocol/buffers.h b/src/protocol/buffers.h
index 1a8f22f..39555eb 100644
--- a/src/protocol/buffers.h
+++ b/src/protocol/buffers.h
@@ -72,6 +72,8 @@ namespace ts::buffer {
                     return 1024;
                 case Bytes_1536:
                     return 1536;
+                case unset:
+                case max:
                 default:
                     return 0;
             }
diff --git a/src/query/command3.h b/src/query/command3.h
index 79f7e49..028fbe5 100644
--- a/src/query/command3.h
+++ b/src/query/command3.h
@@ -184,6 +184,10 @@ namespace ts {
                 this->bulk.reserve(length + (accumulative ? this->bulk.size() : 0));
             }
 
+            inline void reset() {
+                this->bulk.clear();
+            }
+
             inline void put(const std::string_view& key, const std::string_view& value) {
                 size_t begin, end;
                 if(impl::value_raw_impl(this->bulk, key, begin, &end)) {