diff --git a/tests/domain/model-instance.command.test.ts b/tests/domain/model-instance.command.test.ts
new file mode 100644
index 00000000..ea0e7ed3
--- /dev/null
+++ b/tests/domain/model-instance.command.test.ts
@@ -0,0 +1,163 @@
+import { describe, expect, it } from "vitest";
+
+import { createEditorStore } from "../../src/app/editor-store";
+import { createImportModelAssetCommand } from "../../src/commands/import-model-asset-command";
+import { createUpsertModelInstanceCommand } from "../../src/commands/upsert-model-instance-command";
+import { createModelInstance } from "../../src/assets/model-instances";
+import { createProjectAssetStorageKey, type ModelAssetRecord } from "../../src/assets/project-assets";
+import { createEmptySceneDocument } from "../../src/document/scene-document";
+
+describe("model instance commands", () => {
+  const modelAsset = {
+    id: "asset-model-triangle",
+    kind: "model",
+    sourceName: "tiny-triangle.gltf",
+    mimeType: "model/gltf+json",
+    storageKey: createProjectAssetStorageKey("asset-model-triangle"),
+    byteLength: 36,
+    metadata: {
+      kind: "model",
+      format: "gltf",
+      sceneName: "Fixture Triangle Scene",
+      nodeCount: 2,
+      meshCount: 1,
+      materialNames: ["Fixture Material"],
+      textureNames: [],
+      animationNames: [],
+      boundingBox: {
+        min: {
+          x: 0,
+          y: 0,
+          z: 0
+        },
+        max: {
+          x: 1,
+          y: 1,
+          z: 0
+        },
+        size: {
+          x: 1,
+          y: 1,
+          z: 0
+        }
+      },
+      warnings: []
+    }
+  } satisfies ModelAssetRecord;
+
+  it("imports a model asset and placed model instance through undo and redo", () => {
+    const store = createEditorStore();
+    const modelInstance = createModelInstance({
+      id: "model-instance-triangle",
+      assetId: modelAsset.id,
+      name: "Fixture Triangle",
+      position: {
+        x: 4,
+        y: 2,
+        z: -3
+      },
+      rotationDegrees: {
+        x: 0,
+        y: 45,
+        z: 0
+      },
+      scale: {
+        x: 1.5,
+        y: 2,
+        z: 1.5
+      }
+    });
+
+    store.executeCommand(
+      createImportModelAssetCommand({
+        asset: modelAsset,
+        modelInstance,
+        label: "Import fixture triangle"
+      })
+    );
+
+    expect(store.getState().document.assets[modelAsset.id]).toEqual(modelAsset);
+    expect(store.getState().document.modelInstances[modelInstance.id]).toEqual(modelInstance);
+    expect(store.getState().selection).toEqual({
+      kind: "modelInstances",
+      ids: [modelInstance.id]
+    });
+
+    expect(store.undo()).toBe(true);
+    expect(store.getState().document.assets).toEqual({});
+    expect(store.getState().document.modelInstances).toEqual({});
+
+    expect(store.redo()).toBe(true);
+    expect(store.getState().document.assets[modelAsset.id]).toEqual(modelAsset);
+    expect(store.getState().document.modelInstances[modelInstance.id]).toEqual(modelInstance);
+  });
+
+  it("updates an existing model instance transform without changing the asset reference", () => {
+    const existingModelInstance = createModelInstance({
+      id: "model-instance-triangle",
+      assetId: modelAsset.id,
+      position: {
+        x: 1,
+        y: 0,
+        z: 1
+      },
+      rotationDegrees: {
+        x: 0,
+        y: 0,
+        z: 0
+      },
+      scale: {
+        x: 1,
+        y: 1,
+        z: 1
+      }
+    });
+    const store = createEditorStore({
+      initialDocument: {
+        ...createEmptySceneDocument({ name: "Model Instance Scene" }),
+        assets: {
+          [modelAsset.id]: modelAsset
+        },
+        modelInstances: {
+          [existingModelInstance.id]: existingModelInstance
+        }
+      }
+    });
+    const updatedModelInstance = createModelInstance({
+      id: existingModelInstance.id,
+      assetId: modelAsset.id,
+      name: existingModelInstance.name,
+      position: {
+        x: 5,
+        y: 1,
+        z: -2
+      },
+      rotationDegrees: {
+        x: 15,
+        y: 90,
+        z: 0
+      },
+      scale: {
+        x: 2,
+        y: 2,
+        z: 2
+      }
+    });
+
+    store.executeCommand(
+      createUpsertModelInstanceCommand({
+        modelInstance: updatedModelInstance,
+        label: "Update fixture triangle"
+      })
+    );
+
+    expect(store.getState().document.modelInstances[existingModelInstance.id]).toEqual(updatedModelInstance);
+    expect(store.getState().document.assets[modelAsset.id]).toEqual(modelAsset);
+
+    expect(store.undo()).toBe(true);
+    expect(store.getState().document.modelInstances[existingModelInstance.id]).toEqual(existingModelInstance);
+
+    expect(store.redo()).toBe(true);
+    expect(store.getState().document.modelInstances[existingModelInstance.id]).toEqual(updatedModelInstance);
+  });
+});