diff --git a/modeling-cmds/openapi/api.json b/modeling-cmds/openapi/api.json
index 2a9e2e23..52ce0100 100644
--- a/modeling-cmds/openapi/api.json
+++ b/modeling-cmds/openapi/api.json
@@ -4134,6 +4134,13 @@
                   }
                 ]
               },
+              "imported_files": {
+                "description": "Original imported files to embed in glTF source metadata. Paths are relative to the source project. Other export formats ignore these files.",
+                "type": "array",
+                "items": {
+                  "$ref": "#/components/schemas/ImportFile"
+                }
+              },
               "kcl_source": {
                 "nullable": true,
                 "description": "KCL source to embed in formats that support source metadata.",
@@ -4176,6 +4183,13 @@
                   }
                 ]
               },
+              "imported_files": {
+                "description": "Original imported files to embed in glTF source metadata. Paths are relative to the source project. Other export formats ignore these files.",
+                "type": "array",
+                "items": {
+                  "$ref": "#/components/schemas/ImportFile"
+                }
+              },
               "kcl_source": {
                 "nullable": true,
                 "description": "KCL source to embed in formats that support source metadata.",
diff --git a/modeling-cmds/src/def_enum.rs b/modeling-cmds/src/def_enum.rs
index 6720e6d8..0b5eb6cc 100644
--- a/modeling-cmds/src/def_enum.rs
+++ b/modeling-cmds/src/def_enum.rs
@@ -696,6 +696,11 @@ define_modeling_cmd_enum! {
             /// KCL source to embed in formats that support source metadata.
             #[serde(default, skip_serializing_if = "Option::is_none")]
             pub kcl_source: Option<KclProject>,
+            /// Original imported files to embed in glTF source metadata.
+            /// Paths are relative to the source project. Other export formats ignore these files.
+            #[builder(default)]
+            #[serde(default, skip_serializing_if = "Vec::is_empty")]
+            pub imported_files: Vec<super::ImportFile>,
         }
 
         /// Export the scene to a file.
@@ -715,6 +720,11 @@ define_modeling_cmd_enum! {
             /// KCL source to embed in formats that support source metadata.
             #[serde(default, skip_serializing_if = "Option::is_none")]
             pub kcl_source: Option<KclProject>,
+            /// Original imported files to embed in glTF source metadata.
+            /// Paths are relative to the source project. Other export formats ignore these files.
+            #[builder(default)]
+            #[serde(default, skip_serializing_if = "Vec::is_empty")]
+            pub imported_files: Vec<super::ImportFile>,
         }
 
         /// What is this entity's parent?
diff --git a/modeling-cmds/tests/export_imported_files.rs b/modeling-cmds/tests/export_imported_files.rs
new file mode 100644
index 00000000..75be97d5
--- /dev/null
+++ b/modeling-cmds/tests/export_imported_files.rs
@@ -0,0 +1,63 @@
+//! Compatibility and byte-preservation tests for original files supplied with exports.
+
+use kittycad_modeling_cmds::{
+    each_cmd::{Export, Export3d},
+    format::{gltf::export::Options, OutputFormat3d},
+    ImportFile, ModelingCmd,
+};
+use serde_json::json;
+
+#[test]
+fn old_export_requests_and_builders_omit_imported_files() {
+    let format = OutputFormat3d::Gltf(Options::default());
+    for command in [
+        ModelingCmd::from(Export3d::builder().format(format.clone()).build()),
+        ModelingCmd::from(Export::builder().format(format.clone()).build()),
+    ] {
+        let value = serde_json::to_value(&command).unwrap();
+        assert!(value.get("imported_files").is_none());
+        assert_eq!(serde_json::from_value::<ModelingCmd>(value).unwrap(), command);
+    }
+}
+
+#[test]
+fn both_export_commands_round_trip_original_binary_files() {
+    let files = vec![
+        ImportFile::builder()
+            .path("parts/reference.step".to_owned())
+            .data(vec![0, 255, 128, 13, 10])
+            .build(),
+        ImportFile::builder()
+            .path("parts/empty.bin".to_owned())
+            .data(Vec::new())
+            .build(),
+    ];
+    let format = OutputFormat3d::Gltf(Options::default());
+    for command in [
+        ModelingCmd::from(
+            Export3d::builder()
+                .format(format.clone())
+                .imported_files(files.clone())
+                .build(),
+        ),
+        ModelingCmd::from(
+            Export::builder()
+                .format(format.clone())
+                .imported_files(files.clone())
+                .build(),
+        ),
+    ] {
+        let value = serde_json::to_value(&command).unwrap();
+        assert_eq!(
+            value["imported_files"],
+            json!([
+                {"path": "parts/reference.step", "data": [0, 255, 128, 13, 10]},
+                {"path": "parts/empty.bin", "data": []}
+            ])
+        );
+        assert_eq!(serde_json::from_value::<ModelingCmd>(value).unwrap(), command);
+        let bson = bson::to_vec(&command).unwrap();
+        assert_eq!(bson::from_slice::<ModelingCmd>(&bson).unwrap(), command);
+        assert!(format!("{command:?}").contains("<redacted>"));
+    }
+}