diff --git a/crates/fj-kernel/src/insert.rs b/crates/fj-kernel/src/insert.rs
index 50e9bb063..90b50ff41 100644
--- a/crates/fj-kernel/src/insert.rs
+++ b/crates/fj-kernel/src/insert.rs
@@ -25,7 +25,7 @@ macro_rules! impl_insert {
                 fn insert(self, objects: &mut Service<Objects>) -> Handle<Self>
                 {
                     let handle = objects.$store.reserve();
-                    objects.insert(handle.clone(), self);
+                    objects.insert((handle.clone(), self).into());
                     handle
                 }
             }
diff --git a/crates/fj-kernel/src/objects/object.rs b/crates/fj-kernel/src/objects/object.rs
index 603453ba4..2c22aa16f 100644
--- a/crates/fj-kernel/src/objects/object.rs
+++ b/crates/fj-kernel/src/objects/object.rs
@@ -1,5 +1,3 @@
-use std::any::Any;
-
 use crate::{
     objects::{
         Cycle, Face, GlobalEdge, HalfEdge, Objects, Shell, Sketch, Solid,
@@ -24,23 +22,6 @@ macro_rules! object {
             )*
         }
 
-        impl<F: Form> Object<F> {
-            /// Convert the `Object` into the requested inner type
-            pub fn as_inner<T>(&self) -> Option<&F::Form<T>>
-                where
-                    Self: 'static,
-                    F::Form<T>: Any,
-            {
-                match self {
-                    $(
-                        Self::$ty(object) =>
-                            (object as &dyn Any).downcast_ref(),
-
-                    )*
-                }
-            }
-        }
-
         impl Object<BehindHandle> {
             /// Access the ID of the object
             pub fn id(&self) -> ObjectId {
diff --git a/crates/fj-kernel/src/services/mod.rs b/crates/fj-kernel/src/services/mod.rs
index a42373e82..346a3ef7a 100644
--- a/crates/fj-kernel/src/services/mod.rs
+++ b/crates/fj-kernel/src/services/mod.rs
@@ -13,7 +13,7 @@ use parking_lot::Mutex;
 use crate::objects::Objects;
 
 pub use self::{
-    objects::ServiceObjectsExt,
+    objects::{InsertObject, Operation, ServiceObjectsExt},
     service::{Service, State},
     validation::{Validation, ValidationFailed},
 };
diff --git a/crates/fj-kernel/src/services/objects.rs b/crates/fj-kernel/src/services/objects.rs
index a5defbe26..d5f530fa8 100644
--- a/crates/fj-kernel/src/services/objects.rs
+++ b/crates/fj-kernel/src/services/objects.rs
@@ -1,19 +1,14 @@
-use crate::{
-    objects::{Object, Objects, WithHandle},
-    storage::Handle,
-};
+use crate::objects::{Object, Objects, WithHandle};
 
 use super::{Service, State};
 
 impl State for Objects {
-    type Command = InsertObject;
-    type Event = ObjectToInsert;
+    type Command = Operation;
+    type Event = InsertObject;
 
     fn decide(&self, command: Self::Command, events: &mut Vec<Self::Event>) {
-        let event = ObjectToInsert {
-            object: command.object,
-        };
-        events.push(event);
+        let Operation::InsertObject { object } = command;
+        events.push(InsertObject { object });
     }
 
     fn evolve(&mut self, event: &Self::Event) {
@@ -22,18 +17,24 @@ impl State for Objects {
 }
 
 /// Command for `Service<Objects>`
-///
-/// You might prefer to use [`ServiceObjectsExt::insert`], which is a convenient
-/// wrapper around `Service<Objects>::execute`.
-#[derive(Clone, Debug)]
-pub struct InsertObject {
-    /// The object to insert
-    pub object: Object<WithHandle>,
+#[derive(Debug)]
+pub enum Operation {
+    /// Insert an object into the stores
+    ///
+    /// This is the one primitive operation that all other operations are built
+    /// upon.
+    ///
+    /// You might prefer to use [`ServiceObjectsExt::insert`], which is a
+    /// convenient wrapper around `Service<Objects>::execute`.
+    InsertObject {
+        /// The object to insert
+        object: Object<WithHandle>,
+    },
 }
 
 /// Event produced by `Service<Objects>`
 #[derive(Clone, Debug)]
-pub struct ObjectToInsert {
+pub struct InsertObject {
     /// The object to insert
     pub object: Object<WithHandle>,
 }
@@ -41,18 +42,11 @@ pub struct ObjectToInsert {
 /// Convenient API for `Service<Objects>`
 pub trait ServiceObjectsExt {
     /// Insert an object
-    fn insert<T>(&mut self, handle: Handle<T>, object: T)
-    where
-        (Handle<T>, T): Into<Object<WithHandle>>;
+    fn insert(&mut self, object: Object<WithHandle>);
 }
 
 impl ServiceObjectsExt for Service<Objects> {
-    fn insert<T>(&mut self, handle: Handle<T>, object: T)
-    where
-        (Handle<T>, T): Into<Object<WithHandle>>,
-    {
-        self.execute(InsertObject {
-            object: (handle, object).into(),
-        });
+    fn insert(&mut self, object: Object<WithHandle>) {
+        self.execute(Operation::InsertObject { object });
     }
 }
diff --git a/crates/fj-kernel/src/services/validation.rs b/crates/fj-kernel/src/services/validation.rs
index bd7369201..5e0717a8f 100644
--- a/crates/fj-kernel/src/services/validation.rs
+++ b/crates/fj-kernel/src/services/validation.rs
@@ -6,7 +6,7 @@ use crate::{
     validate::ValidationError,
 };
 
-use super::{objects::ObjectToInsert, State};
+use super::{objects::InsertObject, State};
 
 /// Errors that occurred while validating the objects inserted into the stores
 #[derive(Default)]
@@ -33,7 +33,7 @@ impl Drop for Validation {
 }
 
 impl State for Validation {
-    type Command = ObjectToInsert;
+    type Command = InsertObject;
     type Event = ValidationFailed;
 
     fn decide(&self, command: Self::Command, events: &mut Vec<Self::Event>) {