diff --git a/api/proto/common/commands/project_commands.proto b/api/proto/common/commands/project_commands.proto
index 8117715a24..90c6fba931 100644
--- a/api/proto/common/commands/project_commands.proto
+++ b/api/proto/common/commands/project_commands.proto
@@ -35,6 +35,22 @@ message NetClassesResponse
 }
 
 
+message SetNetClasses
+{
+  repeated kiapi.common.project.NetClass net_classes = 1;
+
+  // Whether to merge or replace the existing netclasses with the contents of this message
+  // Note that this only happens at the level of netclass name: for example, if merge_mode is set to
+  // MMM_MERGE, the design has netclasses ["Default", "HV"], and this message has netclasses
+  // ["Default", "LV"], the resulting set will be ["Default", "HV", "LV"] -- the Default netclass
+  // will have its properties replaced with those in this message, the "LV" netclass will be added,
+  // and the "HV" netclass will be left alone.  If merge_mode is set to MMM_REPLACE, the "HV" class
+  // will be erased.  Note that there must always be a "Default" netclass, so it will not be erased
+  // even if merge_mode is MMM_REPLACE and there is no "Default" class specified in this message.
+  kiapi.common.types.MapMergeMode merge_mode = 3;
+}
+
+
 message ExpandTextVariables
 {
   kiapi.common.types.DocumentSpecifier document = 1;
diff --git a/api/proto/common/types/project_settings.proto b/api/proto/common/types/project_settings.proto
index 179bebc5c4..ba2796a6b2 100644
--- a/api/proto/common/types/project_settings.proto
+++ b/api/proto/common/types/project_settings.proto
@@ -26,12 +26,48 @@ syntax = "proto3";
 
 package kiapi.common.project;
 
+import "common/types/base_types.proto";
+import "common/types/enums.proto";
+import "board/board_types.proto";
+
+message NetClassBoardSettings
+{
+  optional kiapi.common.types.Distance clearance = 1;
+  optional kiapi.common.types.Distance track_width = 2;
+  optional kiapi.common.types.Distance diff_pair_track_width = 3;
+  optional kiapi.common.types.Distance diff_pair_gap = 4;
+  optional kiapi.common.types.Distance diff_pair_via_gap = 5;
+
+  // The default padstack to use for vias belonging to this netclass
+  // Currently KiCad only supports specifying the drill diameter and annular size on all layers for
+  // netclass via stacks.  Complex padstacks and other via features cannot be specified here.
+  optional kiapi.board.types.PadStack via_stack = 6;
+
+  // The default padstack to use for microvias belonging to this netclass
+  // Currently KiCad only supports specifying the drill diameter and annular size on all layers for
+  // netclass via stacks.  Complex padstacks and other via features cannot be specified here.
+  optional kiapi.board.types.PadStack microvia_stack = 7;
+
+  optional kiapi.common.types.Color color = 8;
+}
+
+message NetClassSchematicSettings
+{
+  optional kiapi.common.types.Distance wire_width = 1;
+  optional kiapi.common.types.Distance bus_width = 2;
+  optional kiapi.common.types.Color color = 3;
+  optional kiapi.common.types.StrokeLineStyle line_style = 4;
+}
 
 message NetClass
 {
   // The name of the netclass (the literal string "Default" for the default netclass)
   string name = 1;
 
+  optional int32 priority = 2;
+
+  optional NetClassBoardSettings board = 3;
+  optional NetClassSchematicSettings schematic = 4;
 }
 
 message TextVariables
diff --git a/common/api/api_handler_common.cpp b/common/api/api_handler_common.cpp
index d3c91d497e..5a2572b0f5 100644
--- a/common/api/api_handler_common.cpp
+++ b/common/api/api_handler_common.cpp
@@ -45,6 +45,7 @@ API_HANDLER_COMMON::API_HANDLER_COMMON() :
 {
     registerHandler<commands::GetVersion, GetVersionResponse>( &API_HANDLER_COMMON::handleGetVersion );
     registerHandler<GetNetClasses, NetClassesResponse>( &API_HANDLER_COMMON::handleGetNetClasses );
+    registerHandler<SetNetClasses, Empty>( &API_HANDLER_COMMON::handleSetNetClasses );
     registerHandler<Ping, Empty>( &API_HANDLER_COMMON::handlePing );
     registerHandler<GetTextExtents, types::Box2>( &API_HANDLER_COMMON::handleGetTextExtents );
     registerHandler<GetTextAsShapes, GetTextAsShapesResponse>(
@@ -85,15 +86,57 @@ HANDLER_RESULT<NetClassesResponse> API_HANDLER_COMMON::handleGetNetClasses(
     std::shared_ptr<NET_SETTINGS>& netSettings =
             Pgm().GetSettingsManager().Prj().GetProjectFile().m_NetSettings;
 
-    for( const auto& [name, netClass] : netSettings->GetNetclasses() )
+    google::protobuf::Any any;
+
+    netSettings->GetDefaultNetclass()->Serialize( any );
+    any.UnpackTo( reply.add_net_classes() );
+
+    for( const auto& netClass : netSettings->GetNetclasses() | std::views::values )
     {
-        reply.add_net_classes()->set_name( name.ToStdString() );
+        netClass->Serialize( any );
+        any.UnpackTo( reply.add_net_classes() );
     }
 
     return reply;
 }
 
 
+HANDLER_RESULT<Empty> API_HANDLER_COMMON::handleSetNetClasses(
+        const HANDLER_CONTEXT<SetNetClasses>& aCtx )
+{
+    std::shared_ptr<NET_SETTINGS>& netSettings =
+            Pgm().GetSettingsManager().Prj().GetProjectFile().m_NetSettings;
+
+    if( aCtx.Request.merge_mode() == MapMergeMode::MMM_REPLACE )
+        netSettings->ClearNetclasses();
+
+    auto netClasses = netSettings->GetNetclasses();
+    google::protobuf::Any any;
+
+    for( const auto& ncProto : aCtx.Request.net_classes() )
+    {
+        any.PackFrom( ncProto );
+        wxString name = wxString::FromUTF8( ncProto.name() );
+
+        if( name == wxT( "Default" ) )
+        {
+            netSettings->GetDefaultNetclass()->Deserialize( any );
+        }
+        else
+        {
+            if( !netClasses.contains( name ) )
+                netClasses.insert( { name, std::make_shared<NETCLASS>( name, false ) } );
+
+            netClasses[name]->Deserialize( any );
+        }
+    }
+
+    netSettings->SetNetclasses( netClasses );
+
+    return Empty();
+}
+
+
 HANDLER_RESULT<Empty> API_HANDLER_COMMON::handlePing( const HANDLER_CONTEXT<Ping>& aCtx )
 {
     return Empty();
diff --git a/common/api/api_utils.cpp b/common/api/api_utils.cpp
index 9ce17a65a0..ab2523fb5d 100644
--- a/common/api/api_utils.cpp
+++ b/common/api/api_utils.cpp
@@ -212,4 +212,24 @@ KICOMMON_API SHAPE_POLY_SET UnpackPolySet( const types::PolySet& aInput )
     return sps;
 }
 
+
+KICOMMON_API void PackColor( types::Color& aOutput, const KIGFX::COLOR4D& aInput )
+{
+    aOutput.set_r( aInput.r );
+    aOutput.set_g( aInput.g );
+    aOutput.set_b( aInput.b );
+    aOutput.set_a( aInput.a );
+}
+
+
+KICOMMON_API KIGFX::COLOR4D UnpackColor( const types::Color& aInput )
+{
+    double r = std::clamp( aInput.r(), 0.0, 1.0 );
+    double g = std::clamp( aInput.g(), 0.0, 1.0 );
+    double b = std::clamp( aInput.b(), 0.0, 1.0 );
+    double a = std::clamp( aInput.a(), 0.0, 1.0 );
+
+    return KIGFX::COLOR4D( r, g, b, a );
+}
+
 } // namespace kiapi::common
diff --git a/common/netclass.cpp b/common/netclass.cpp
index 0c15ee47a3..e9583f5900 100644
--- a/common/netclass.cpp
+++ b/common/netclass.cpp
@@ -27,6 +27,9 @@
 #include <netclass.h>
 #include <macros.h>
 #include <base_units.h>
+#include <api/api_enums.h>
+#include <api/api_utils.h>
+#include <api/common/types/project_settings.pb.h>
 
 // This will get mapped to "kicad_default" in the specctra_export.
 const char NETCLASS::Default[] = "Default";
@@ -126,6 +129,125 @@ bool NETCLASS::operator==( const NETCLASS& other ) const
 }
 
 
+void NETCLASS::Serialize( google::protobuf::Any &aContainer ) const
+{
+    using namespace kiapi::common;
+    project::NetClass nc;
+
+    nc.set_name( m_Name.ToUTF8() );
+    nc.set_priority( m_Priority );
+
+    project::NetClassBoardSettings* board = nc.mutable_board();
+
+    if( m_Clearance )
+        board->mutable_clearance()->set_value_nm( *m_Clearance );
+
+    if( m_TrackWidth )
+        board->mutable_track_width()->set_value_nm( *m_TrackWidth );
+
+    if( m_diffPairWidth )
+        board->mutable_diff_pair_track_width()->set_value_nm( *m_diffPairWidth );
+
+    if( m_diffPairGap )
+        board->mutable_diff_pair_gap()->set_value_nm( *m_diffPairGap );
+
+    if( m_diffPairViaGap )
+        board->mutable_diff_pair_via_gap()->set_value_nm( *m_diffPairViaGap );
+
+    if( m_ViaDia )
+    {
+        kiapi::board::types::PadStackLayer* layer = board->mutable_via_stack()->add_copper_layers();
+        layer->set_shape( kiapi::board::types::PSS_CIRCLE );
+        layer->set_layer( kiapi::board::types::BoardLayer::BL_F_Cu );
+        PackVector2( *layer->mutable_size(), { *m_ViaDia, *m_ViaDia } );
+    }
+
+    if( m_ViaDrill )
+    {
+        PackVector2( *board->mutable_via_stack()->mutable_drill()->mutable_diameter(),
+                     { *m_ViaDrill, *m_ViaDrill } );
+    }
+
+    if( m_pcbColor != COLOR4D::UNSPECIFIED )
+        PackColor( *board->mutable_color(), m_pcbColor );
+
+    project::NetClassSchematicSettings* schematic = nc.mutable_schematic();
+
+    if( m_wireWidth )
+        schematic->mutable_wire_width()->set_value_nm( *m_wireWidth );
+
+    if( m_busWidth )
+        schematic->mutable_bus_width()->set_value_nm( *m_busWidth );
+
+    if( m_schematicColor != COLOR4D::UNSPECIFIED )
+        PackColor( *schematic->mutable_color(), m_schematicColor );
+
+    if( m_lineStyle )
+    {
+        // TODO(JE) resolve issues with moving to kicommon
+        // schematic->set_line_style( ToProtoEnum<LINE_STYLE, types::StrokeLineStyle>(
+        //         static_cast<LINE_STYLE>( *m_lineStyle ) ) );
+    }
+
+    aContainer.PackFrom( nc );
+}
+
+
+bool NETCLASS::Deserialize( const google::protobuf::Any &aContainer )
+{
+    using namespace kiapi::common;
+    project::NetClass nc;
+
+    if( !aContainer.UnpackTo( &nc ) )
+        return false;
+
+    m_Name = wxString::FromUTF8( nc.name() );
+    m_Priority = nc.priority();
+
+    if( nc.board().has_clearance() )
+        m_Clearance = nc.board().clearance().value_nm();
+
+    if( nc.board().has_track_width() )
+        m_TrackWidth = nc.board().track_width().value_nm();
+
+    if( nc.board().has_diff_pair_track_width() )
+        m_diffPairWidth = nc.board().diff_pair_track_width().value_nm();
+
+    if( nc.board().has_diff_pair_gap() )
+        m_diffPairGap = nc.board().diff_pair_gap().value_nm();
+
+    if( nc.board().has_diff_pair_via_gap() )
+        m_diffPairViaGap = nc.board().diff_pair_via_gap().value_nm();
+
+    if( nc.board().has_via_stack() )
+    {
+        if( nc.board().via_stack().copper_layers_size() > 0 )
+            m_ViaDia = nc.board().via_stack().copper_layers().at( 0 ).size().x_nm();
+
+        if( nc.board().via_stack().has_drill() )
+            m_ViaDrill = nc.board().via_stack().drill().diameter().x_nm();
+    }
+
+    if( nc.board().has_color() )
+        m_pcbColor = UnpackColor( nc.board().color() );
+
+    if( nc.schematic().has_wire_width() )
+        m_wireWidth = nc.schematic().wire_width().value_nm();
+
+    if( nc.schematic().has_bus_width() )
+        m_busWidth = nc.schematic().bus_width().value_nm();
+
+    if( nc.schematic().has_color() )
+        m_schematicColor = UnpackColor( nc.schematic().color() );
+
+    // TODO(JE) resolve issues with moving to kicommon
+    // if( nc.schematic().has_line_style() )
+    //     m_lineStyle = static_cast<int>( FromProtoEnum<LINE_STYLE>( nc.schematic().line_style() ) );
+
+    return true;
+}
+
+
 const std::vector<NETCLASS*>& NETCLASS::GetConstituentNetclasses() const
 {
     return m_constituents;
diff --git a/include/api/api_handler_common.h b/include/api/api_handler_common.h
index 06f14e5128..8b782b840e 100644
--- a/include/api/api_handler_common.h
+++ b/include/api/api_handler_common.h
@@ -44,6 +44,9 @@ private:
     HANDLER_RESULT<commands::NetClassesResponse> handleGetNetClasses(
         const HANDLER_CONTEXT<commands::GetNetClasses>& aCtx );
 
+    HANDLER_RESULT<Empty> handleSetNetClasses(
+        const HANDLER_CONTEXT<commands::SetNetClasses>& aCtx );
+
     HANDLER_RESULT<Empty> handlePing( const HANDLER_CONTEXT<commands::Ping>& aCtx );
 
     HANDLER_RESULT<types::Box2> handleGetTextExtents(
diff --git a/include/api/api_utils.h b/include/api/api_utils.h
index 8cd4897113..18e0587af4 100644
--- a/include/api/api_utils.h
+++ b/include/api/api_utils.h
@@ -31,6 +31,7 @@
 #include <geometry/shape_line_chain.h>
 #include <math/vector2d.h>
 #include <math/vector3.h>
+#include <gal/color4d.h>
 
 class SHAPE_LINE_CHAIN;
 
@@ -72,6 +73,10 @@ KICOMMON_API void PackPolySet( types::PolySet& aOutput, const SHAPE_POLY_SET& aI
 
 KICOMMON_API SHAPE_POLY_SET UnpackPolySet( const types::PolySet& aInput );
 
+KICOMMON_API void PackColor( types::Color& aOutput, const KIGFX::COLOR4D& aInput );
+
+KICOMMON_API KIGFX::COLOR4D UnpackColor( const types::Color& aInput );
+
 } // namespace kiapi::common
 
 #endif //KICAD_API_UTILS_H
diff --git a/include/netclass.h b/include/netclass.h
index 78e6b2e15b..a4c9b14bcd 100644
--- a/include/netclass.h
+++ b/include/netclass.h
@@ -32,6 +32,7 @@
 #include <kicommon.h>
 #include <macros_swig.h>
 #include <stroke_params.h>
+#include <api/serializable.h>
 
 using KIGFX::COLOR4D;
 
@@ -40,7 +41,7 @@ DECL_SET_FOR_SWIG( STRINGSET, wxString )
 /**
  * A collection of nets and the parameters used to route or test these nets.
  */
-class KICOMMON_API NETCLASS
+class KICOMMON_API NETCLASS : public SERIALIZABLE
 {
 public:
     static const char Default[];        ///< the name of the default NETCLASS
@@ -62,6 +63,9 @@ public:
         return wxT( "NETCLASS" );
     }
 
+    void Serialize( google::protobuf::Any &aContainer ) const override;
+    bool Deserialize( const google::protobuf::Any &aContainer ) override;
+
     /// @brief Resets all parent fields to point to this netclass
     void ResetParents();