diff --git a/README.md b/README.md
index 3d28599..aa7af29 100644
--- a/README.md
+++ b/README.md
@@ -2514,7 +2514,11 @@ dataset_object = client.create_dataset_object(
             "value": "dog",
             "type": "bbox" # type can be 'bbox', 'segmentation'.
         }
-    ]
+    ],
+    custom_metadata={
+      "key": "value",
+      "metadata": "metadata-value"
+    }
 )
 ```
 
@@ -2568,6 +2572,10 @@ See API docs for details.
             "confidenceScore": -1
         }
     ],
+  "customMetadata": {
+    "key": "value",
+    "metadata": "metadata-value"
+  },
     'createdAt': '2022-10-30T08:32:20.748Z',
     'updatedAt': '2022-10-30T08:32:20.748Z'
 }
diff --git a/fastlabel/__init__.py b/fastlabel/__init__.py
index 044a2ec..995ed36 100644
--- a/fastlabel/__init__.py
+++ b/fastlabel/__init__.py
@@ -4050,7 +4050,11 @@ async def __download(base_path: Path, _obj: dict):
                 exist_dataset_objects = json.load(open(output_path))
             with Path(base_path / "annotations.json").open("w") as f:
                 annotations = [
-                    {"name": obj["name"], "annotations": obj["annotations"]}
+                    {
+                        "name": obj["name"],
+                        "annotations": obj["annotations"],
+                        "customMetadata": obj["customMetadata"],
+                    }
                     for obj in objects
                 ]
                 json.dump(
@@ -4076,6 +4080,7 @@ def create_dataset_object(
         file_path: str,
         tags: List[str] = None,
         annotations: List[dict] = None,
+        custom_metadata: Optional[dict[str, str]] = None,
     ) -> dict:
         """
         Create a dataset object.
@@ -4102,6 +4107,8 @@ def create_dataset_object(
             payload["tags"] = tags
         if annotations:
             payload["annotations"] = annotations
+        if custom_metadata:
+            payload["customMetadata"] = custom_metadata
         return self.api.post_request(endpoint, payload=payload)
 
     def delete_dataset_object(self, dataset_id: str, object_name: str) -> None:
@@ -4418,6 +4425,7 @@ def get_histories(
 
         return self.api.get_request(endpoint, params=params)
 
+
 def delete_extra_annotations_parameter(annotations: list) -> list:
     for annotation in annotations:
         annotation.pop("id", None)
@@ -4437,4 +4445,4 @@ def delete_extra_attributes_parameter(attributes: list) -> list:
         attribute.pop("title", None)
         attribute.pop("name", None)
         attribute.pop("type", None)
-    return attributes
\ No newline at end of file
+    return attributes