diff --git a/app/api/tasks.py b/app/api/tasks.py
index e1a4f711..49bf490a 100644
--- a/app/api/tasks.py
+++ b/app/api/tasks.py
@@ -1,5 +1,8 @@
+import itertools
+
 from celery import shared_task
 from django.conf import settings
+from django.contrib.auth import get_user_model
 from django.shortcuts import get_object_or_404
 
 from .models import Document, Label, Project
@@ -9,15 +12,17 @@ from .views.upload.utils import append_field
 
 
 @shared_task
-def injest_data(project_id, filenames, format: str, **kwargs):
+def injest_data(user_id, project_id, filenames, format: str, **kwargs):
     project = get_object_or_404(Project, pk=project_id)
+    user = get_object_or_404(get_user_model(), pk=user_id)
     data_class = get_data_class(project.project_type)
     dataset_class = get_dataset_class(format)
     label_class = get_label_class(project.project_type)
     dataset = dataset_class(
-      filenames=filenames,
-      label_class=label_class,
-      data_class=data_class
+        filenames=filenames,
+        label_class=label_class,
+        data_class=data_class,
+        **kwargs
     )
     annotation_serializer_class = project.get_annotation_serializer()
     for batch in dataset.batch(settings.IMPORT_BATCH_SIZE):
@@ -33,8 +38,11 @@ def injest_data(project_id, filenames, format: str, **kwargs):
         annotation = batch.annotation(mapping)
         for a, d in zip(annotation, data):
             append_field(a, document=d.id)
-        annotation_serializer = annotation_serializer_class(data=annotation, many=True)
+        annotation_serializer = annotation_serializer_class(
+            data=list(itertools.chain(*annotation)),
+            many=True
+        )
         annotation_serializer.is_valid()
-        annotation_serializer.save()
+        annotation_serializer.save(user=user)
 
     return {'error': []}