diff --git a/Cargo.lock b/Cargo.lock
index 51294fb85..aed64f835 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4206,7 +4206,7 @@ dependencies = [
 [[package]]
 name = "opencadcodec"
 version = "0.5.5"
-source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=d96e3fa#d96e3fa2fe5acbeac966f1db4c01142618bf9c79"
+source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=8d23408#8d2340876caef34f68436f62e2c9402be0aabb28"
 dependencies = [
  "ahash 0.8.12",
  "anyhow",
@@ -4229,7 +4229,7 @@ dependencies = [
 [[package]]
 name = "opencadgraph"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/opencadgraph.git?rev=10d0858#10d0858a7252f85df07be4dfa00946658b6979e6"
+source = "git+https://github.com/HakanSeven12/opencadgraph.git?rev=9b5ae39#9b5ae39ea35567e67faf8bc8d20b40e2bbab1177"
 dependencies = [
  "opencadkernel",
  "serde_json",
@@ -4238,7 +4238,7 @@ dependencies = [
 [[package]]
 name = "opencadkernel"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=9cdd36d#9cdd36dc527216ba7929d8cfcdc1b7712a2d4cb8"
+source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=d22a270#d22a270a0af79db9f10428a2d941152f6bb28158"
 dependencies = [
  "cavalier_contours",
  "opencadcodec",
@@ -4249,7 +4249,7 @@ dependencies = [
 [[package]]
 name = "opencadkernel-constraints"
 version = "0.1.0"
-source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=9cdd36d#9cdd36dc527216ba7929d8cfcdc1b7712a2d4cb8"
+source = "git+https://github.com/HakanSeven12/opencadkernel.git?rev=d22a270#d22a270a0af79db9f10428a2d941152f6bb28158"
 dependencies = [
  "nalgebra",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 85cc56ce7..bc0264dda 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -34,10 +34,10 @@ rfd = "0.17"
 clap = { version = "4", features = ["derive", "string"] }
 env_logger = "0.11"
 log = "0.4"
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d96e3fa", features = ["serde"] }
-kernel = { package = "opencadkernel", git = "https://github.com/HakanSeven12/opencadkernel.git", rev = "9cdd36d", features = ["acis", "offset"] }
-kernel-constraints = { package = "opencadkernel-constraints", git = "https://github.com/HakanSeven12/opencadkernel.git", rev = "9cdd36d" }
-graph = { package = "opencadgraph", git = "https://github.com/HakanSeven12/opencadgraph.git", rev = "10d0858" }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8d23408", features = ["serde"] }
+kernel = { package = "opencadkernel", git = "https://github.com/HakanSeven12/opencadkernel.git", rev = "d22a270", features = ["acis", "offset"] }
+kernel-constraints = { package = "opencadkernel-constraints", git = "https://github.com/HakanSeven12/opencadkernel.git", rev = "d22a270" }
+graph = { package = "opencadgraph", git = "https://github.com/HakanSeven12/opencadgraph.git", rev = "9b5ae39" }
 dwg-thumbnailer = { path = "crates/dwg-thumbnailer" }
 flate2 = "1"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "bmp", "tiff"] }
diff --git a/crates/ocs_plugin_api/Cargo.toml b/crates/ocs_plugin_api/Cargo.toml
index 8ac76adc1..1edabd809 100644
--- a/crates/ocs_plugin_api/Cargo.toml
+++ b/crates/ocs_plugin_api/Cargo.toml
@@ -15,7 +15,7 @@ serde_json = { version = "1", optional = true }
 # Pulled in only by the `host` feature, which adds the `opencadcodec`-typed
 # `HostApi` runtime surface. The default crate stays dependency-free so engine
 # crates and external tooling can depend on the manifest/ribbon contract cheaply.
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d96e3fa", optional = true, features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8d23408", optional = true, features = ["serde"] }
 
 # Runtime IPC and serialization (host feature only).
 interprocess = { version = "2", optional = true }
@@ -39,7 +39,7 @@ serde_json = "1"
 serde = { version = "1", features = ["derive"] }
 cargo-lock = "11"
 # opencadcodec is scanned at build time to generate the embedded type registry.
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d96e3fa", features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8d23408", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"
diff --git a/crates/ocs_plugin_api/build.rs b/crates/ocs_plugin_api/build.rs
index 382754826..dda5ba997 100644
--- a/crates/ocs_plugin_api/build.rs
+++ b/crates/ocs_plugin_api/build.rs
@@ -162,6 +162,10 @@ fn generate_type_registry(out_dir: &Path) {
             "AssocConstraintNodeData",
             trace_simple::<codec::objects::AssocConstraintNodeData>,
         ),
+        (
+            "AssocCurveValue",
+            trace_simple::<codec::objects::AssocCurveValue>,
+        ),
         (
             "AssocEvalValue",
             trace_simple::<codec::objects::AssocEvalValue>,
diff --git a/crates/ocs_web_worker/Cargo.toml b/crates/ocs_web_worker/Cargo.toml
index 91ed6035f..7635cc5d7 100644
--- a/crates/ocs_web_worker/Cargo.toml
+++ b/crates/ocs_web_worker/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d96e3fa", features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8d23408", features = ["serde"] }
 bincode = "1.3"
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = "0.1"
diff --git a/plugins/opencad-python/Cargo.lock b/plugins/opencad-python/Cargo.lock
index ac619efe5..b03373f59 100644
--- a/plugins/opencad-python/Cargo.lock
+++ b/plugins/opencad-python/Cargo.lock
@@ -1265,7 +1265,7 @@ dependencies = [
 [[package]]
 name = "opencadcodec"
 version = "0.5.5"
-source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=d96e3fa#d96e3fa2fe5acbeac966f1db4c01142618bf9c79"
+source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=8d23408#8d2340876caef34f68436f62e2c9402be0aabb28"
 dependencies = [
  "ahash 0.8.12",
  "anyhow",
diff --git a/src/entities/object_data.rs b/src/entities/object_data.rs
index 1568dc78e..b0056a369 100644
--- a/src/entities/object_data.rs
+++ b/src/entities/object_data.rs
@@ -228,6 +228,8 @@ fn embedded_name(value: Option<&codec::entities::EmbeddedEntity>) -> &'static st
         Some(codec::entities::EmbeddedEntity::Ellipse(_)) => "Ellipse",
         Some(codec::entities::EmbeddedEntity::Spline(_)) => "Spline",
         Some(codec::entities::EmbeddedEntity::LwPolyline(_)) => "Polyline",
+        // A 2D / 3D polyline profile the modeler keeps as a wire body.
+        Some(codec::entities::EmbeddedEntity::Body { .. }) => "Polyline",
         Some(codec::entities::EmbeddedEntity::Region(_)) => "Region",
         Some(codec::entities::EmbeddedEntity::Ray(_)) => "Ray",
         Some(codec::entities::EmbeddedEntity::XLine(_)) => "XLine",
diff --git a/src/entities/solid3d.rs b/src/entities/solid3d.rs
index b8721f0fe..e2e7c3add 100644
--- a/src/entities/solid3d.rs
+++ b/src/entities/solid3d.rs
@@ -447,6 +447,8 @@ fn embedded_name(entity: Option<&codec::entities::EmbeddedEntity>) -> &'static s
         Some(codec::entities::EmbeddedEntity::Ellipse(_)) => "Ellipse",
         Some(codec::entities::EmbeddedEntity::Spline(_)) => "Spline",
         Some(codec::entities::EmbeddedEntity::LwPolyline(_)) => "Polyline",
+        // A 2D / 3D polyline profile the modeler keeps as a wire body.
+        Some(codec::entities::EmbeddedEntity::Body { .. }) => "Polyline",
         Some(codec::entities::EmbeddedEntity::Region(_)) => "Region",
         Some(codec::entities::EmbeddedEntity::Ray(_)) => "Ray",
         Some(codec::entities::EmbeddedEntity::XLine(_)) => "XLine",
diff --git a/src/modules/model/primitive_cmd.rs b/src/modules/model/primitive_cmd.rs
index 016640de0..cca272072 100644
--- a/src/modules/model/primitive_cmd.rs
+++ b/src/modules/model/primitive_cmd.rs
@@ -1894,7 +1894,7 @@ impl PrimitiveCommand {
         Some((
             placed,
             solid_history::box_op(
-                self.history_transform_axes(origin, x_axis, y_axis),
+                self.history_transform_axes(box_centre(origin, x_axis, y_axis, length, width, height), x_axis, y_axis),
                 length,
                 width,
                 height,
@@ -2024,7 +2024,7 @@ impl PrimitiveCommand {
         Some((
             placed,
             solid_history::wedge_op(
-                self.history_transform_axes(origin, x_axis, y_axis),
+                self.history_transform_axes(box_centre(origin, x_axis, y_axis, length, width, height), x_axis, y_axis),
                 length,
                 width,
                 height,
@@ -3714,3 +3714,9 @@ fn wire(name: &str, points: Vec<[f32; 3]>) -> WireModel {
         ..Default::default()
 }
 }
+
+/// Box and wedge histories are framed at the centre of their bounding box,
+/// as the reference stores them (lengths stay positive).
+fn box_centre(origin: DVec3, x_axis: DVec3, y_axis: DVec3, length: f64, width: f64, height: f64) -> DVec3 {
+    origin + x_axis * (length * 0.5) + y_axis * (width * 0.5) + DVec3::Z * (height * 0.5)
+}
diff --git a/src/scene/convert/acis_kernel.rs b/src/scene/convert/acis_kernel.rs
index d4ede7699..d1affae13 100644
--- a/src/scene/convert/acis_kernel.rs
+++ b/src/scene/convert/acis_kernel.rs
@@ -31,23 +31,14 @@ pub fn tessellate_sat(
     if bodies.is_empty() {
         return None;
     }
+    // The kernel's lift already applies each body's transform record; its
+    // scale still sets the tessellation tolerance.
     let mut placed_bodies = Vec::with_capacity(bodies.len());
     for body in bodies {
         let source = body.provenance.source()?;
         let transform = body_transform(document, source.index() as usize).ok()?;
         let placement_scale = transform.map_or(1.0, |(_, _, scale)| scale.abs());
-        let placed = if let Some((matrix, translation, scale)) = transform {
-            let placement = brep::Placement {
-                x_axis: [scale * matrix[0], scale * matrix[1], scale * matrix[2]],
-                y_axis: [scale * matrix[3], scale * matrix[4], scale * matrix[5]],
-                z_axis: [scale * matrix[6], scale * matrix[7], scale * matrix[8]],
-                origin: translation,
-            };
-            brep::transform(&body, &placement)?
-        } else {
-            body
-        };
-        placed_bodies.push((placed, placement_scale));
+        placed_bodies.push((body, placement_scale));
     }
     let bodies = placed_bodies;
     let resolution = if facet_res.is_finite() && facet_res > 0.0 {
diff --git a/src/scene/convert/solid3d_tess.rs b/src/scene/convert/solid3d_tess.rs
index 987b920a7..1bda680d5 100644
--- a/src/scene/convert/solid3d_tess.rs
+++ b/src/scene/convert/solid3d_tess.rs
@@ -1,6 +1,6 @@
 use codec::entities::acis::{SabReader, SatBody, SatDocument};
 use codec::entities::{Body, Region, Solid3D, Surface};
-use kernel::brep::{self, Body as KernelBody};
+use kernel::brep::Body as KernelBody;
 
 use crate::scene::model::mesh_model::{MeshLodSet, MeshModel};
 
@@ -179,21 +179,8 @@ pub(crate) fn kernel_acis_body(acis: &codec::entities::AcisData) -> Option<Kerne
     if !loss.is_empty() || bodies.len() != 1 {
         return None;
     }
-    let body = bodies.pop()?;
-    let source = body.provenance.source()?;
-    let Some((matrix, translation, scale)) = body_transform(&sat, source.index() as usize).ok()?
-    else {
-        return Some(body);
-    };
-    brep::transform(
-        &body,
-        &brep::Placement {
-            x_axis: [scale * matrix[0], scale * matrix[1], scale * matrix[2]],
-            y_axis: [scale * matrix[3], scale * matrix[4], scale * matrix[5]],
-            z_axis: [scale * matrix[6], scale * matrix[7], scale * matrix[8]],
-            origin: translation,
-        },
-    )
+    // The kernel's lift already applies the body's transform record.
+    bodies.pop()
 }
 
 fn remap_acis_material_bindings(
diff --git a/src/scene/model/solid_history.rs b/src/scene/model/solid_history.rs
index 569f40968..bca6763f6 100644
--- a/src/scene/model/solid_history.rs
+++ b/src/scene/model/solid_history.rs
@@ -278,7 +278,7 @@ pub fn reference_point(operation: &SolidHistoryOperation) -> Option<glam::DVec3>
     match operation {
         SolidHistoryOperation::Box(value) | SolidHistoryOperation::Wedge(value) => world_point(
             value.base.transform,
-            [value.length * 0.5, value.width * 0.5, 0.0],
+            [0.0, 0.0, -value.height * 0.5],
         ),
         SolidHistoryOperation::Sphere(value) => {
             world_point(value.base.transform, [0.0, 0.0, 0.0])
@@ -1615,9 +1615,10 @@ pub fn primitive_properties(
     ) {
         return Vec::new();
     }
-    let Some(operation) = primitive_property_operation(document, handle) else {
+    let Some(mut operation) = primitive_property_operation(document, handle) else {
         return brep_properties(document, handle);
     };
+    corner_frame(&mut operation);
     match &operation {
         SolidHistoryOperation::Box(value) => {
             rectangular_properties(document, handle, value, "Box")
@@ -2414,6 +2415,17 @@ pub fn apply_primitive_property(
     operation: &mut SolidHistoryOperation,
     field: &str,
     value: &str,
+) -> bool {
+    corner_frame(operation);
+    let applied = apply_primitive_property_at_corner(operation, field, value);
+    centre_frame(operation);
+    applied
+}
+
+fn apply_primitive_property_at_corner(
+    operation: &mut SolidHistoryOperation,
+    field: &str,
+    value: &str,
 ) -> bool {
     if let SolidHistoryOperation::Brep(brep_value) = operation {
         if let Some(applied) = apply_brep_position_property(brep_value, field, value) {
@@ -2757,7 +2769,7 @@ fn embedded_entity(value: &EmbeddedEntity) -> Option<EntityType> {
         EmbeddedEntity::Region(value) => EntityType::Region(value.clone()),
         EmbeddedEntity::Ray(value) => EntityType::Ray(value.clone()),
         EmbeddedEntity::XLine(value) => EntityType::XLine(value.clone()),
-        EmbeddedEntity::Unknown { .. } => return None,
+        EmbeddedEntity::Body { .. } | EmbeddedEntity::Unknown { .. } => return None,
     })
 }
 
@@ -3460,6 +3472,9 @@ pub fn primitive_grips(
     let Some(operation) = document.solid_history_operation(handle) else {
         return Vec::new();
     };
+    let mut operation = operation.clone();
+    corner_frame(&mut operation);
+    let operation = &operation;
     if let SolidHistoryOperation::Fillet(value) = operation {
         let Some(radius) = value.radii.first().copied() else {
             return Vec::new();
@@ -3743,6 +3758,17 @@ pub fn apply_primitive_grip(
     operation: &mut SolidHistoryOperation,
     grip_id: usize,
     apply: GripApply,
+) -> bool {
+    corner_frame(operation);
+    let applied = apply_primitive_grip_at_corner(operation, grip_id, apply);
+    centre_frame(operation);
+    applied
+}
+
+fn apply_primitive_grip_at_corner(
+    operation: &mut SolidHistoryOperation,
+    grip_id: usize,
+    apply: GripApply,
 ) -> bool {
     if let SolidHistoryOperation::Revolve(value) = operation {
         if let Some(index) = grip_id.checked_sub(GRIP_REVOLVE_PROFILE_FIRST) {
@@ -4138,3 +4164,23 @@ pub fn chamfer_op(
         ..SolidHistoryChamfer::default()
     })
 }
+
+/// Box and wedge histories are framed at the centre of their bounding box,
+/// as the reference stores them; the editing code here works in the frame at
+/// the base corner. These move a box or wedge between the two frames.
+fn corner_frame(operation: &mut SolidHistoryOperation) {
+    shift_rectangular_frame(operation, -0.5);
+}
+
+fn centre_frame(operation: &mut SolidHistoryOperation) {
+    shift_rectangular_frame(operation, 0.5);
+}
+
+fn shift_rectangular_frame(operation: &mut SolidHistoryOperation, factor: f64) {
+    if let SolidHistoryOperation::Box(value) | SolidHistoryOperation::Wedge(value) = operation {
+        if let Some(current) = matrix(value.base.transform) {
+            let half = glam::DVec3::new(value.length, value.width, value.height) * factor;
+            value.base.transform = (current * glam::DMat4::from_translation(half)).to_cols_array();
+        }
+    }
+}