diff --git a/ansys/api/additive/VERSION b/ansys/api/additive/VERSION
index da27200..fa92cd5 100644
--- a/ansys/api/additive/VERSION
+++ b/ansys/api/additive/VERSION
@@ -1 +1 @@
-1.6.0-dev0
\ No newline at end of file
+1.6.0-dev1
\ No newline at end of file
diff --git a/ansys/api/additive/v0/additive_domain.proto b/ansys/api/additive/v0/additive_domain.proto
index 71505ea..955e866 100644
--- a/ansys/api/additive/v0/additive_domain.proto
+++ b/ansys/api/additive/v0/additive_domain.proto
@@ -247,7 +247,45 @@ message VoxelMeshInput {
     float voxel_size = 3;
 }
 
+
 message VoxelMeshResult {
     string voxel_file = 1; // name of voxel file on server
 }
 
+message InitialMicrostructureInput {
+    uint32 number_of_random_nuclei = 1;
+    double x_dimension = 2;
+    double y_dimension = 3;
+    double z_dimension = 4;
+}
+
+message Microstructure3DInput {
+    double x_dimension = 1;
+    double y_dimension = 2;
+    double z_dimension = 3;
+    optional bytes initial_grain_data = 4;
+    optional bytes initial_euler_angle_data = 5;
+    optional double x_origin = 16;
+    optional double y_origin = 17;
+    optional double z_origin = 18;
+    optional double deposit_layer_thickness = 19;
+    optional uint32 num_deposit_layers = 20;
+    optional uint32 first_deposit_layer = 21;
+    optional double thermal_domain_depth = 22;
+    optional double x_thermal_domain_grid_spacing = 23;
+    optional double y_thermal_domain_grid_spacing = 24;
+    optional double z_thermal_domain_grid_spacing = 25;
+    optional bool use_transient_bulk_nucleation = 26;
+    optional double max_bulk_nucleation_density = 27;
+    optional bool run_initial_microstructure = 28;
+    optional InitialMicrostructureInput initial_microstructure_input = 29;
+    optional MachineSettings machine = 30;
+    optional AdditiveMaterial material = 31;
+    optional double use_provided_initial_microstructure_data = 32;
+    optional string thermal_data_file_type = 33;
+}
+
+message Microstructure3DResult {
+    bytes three_d_vtk = 1;
+    MicrostructureResult two_d_result = 2;
+}
\ No newline at end of file
diff --git a/ansys/api/additive/v0/additive_simulation.proto b/ansys/api/additive/v0/additive_simulation.proto
index e5aaf58..c07a555 100644
--- a/ansys/api/additive/v0/additive_simulation.proto
+++ b/ansys/api/additive/v0/additive_simulation.proto
@@ -23,6 +23,7 @@ message SimulationResponse {
 		MicrostructureResult microstructure_result = 14;
 		ThermalHistoryResult thermal_history_result = 15;
 		ThermalStrainResult thermal_strain_result = 16;
+		Microstructure3DResult microstructure_3d_result = 17;
 	}
 }