diff --git a/src/api/batch_decoder.py b/src/api/batch_decoder.py
index f9accff..ade56fa 100644
--- a/src/api/batch_decoder.py
+++ b/src/api/batch_decoder.py
@@ -150,7 +150,8 @@ def save_prediction_outputs(
     group_ids: List[str],
     image_ids: List[str],
     base_output_path: str,
-    image_metadata: List[Dict]
+    image_metadata: List[Dict],
+    temp_dir: str = None
 ) -> List[str]:
     """
     Generate output texts based on predictions and save to files atomically.
@@ -167,6 +168,9 @@ def save_prediction_outputs(
         Base path where prediction outputs should be saved.
     image_metadata: List[Dict]
         List of metadata dictionaries for each image.
+    temp_dir: str, optional
+        Path to use for temporary files. If None, a subdirectory of
+        base_output_path is used.
 
     Returns
     -------
@@ -182,14 +186,21 @@ def save_prediction_outputs(
     """
     output_texts = []
 
-    # Create a temporary directory for intermediate files
-    with tempfile.TemporaryDirectory(prefix="prediction_outputs_") as temp_dir:
+    # If no temp_dir is provided, create one as a subdirectory of
+    # base_output_path
+    if temp_dir is None:
+        temp_dir = os.path.join(base_output_path, '.temp_prediction_outputs')
+
+    os.makedirs(temp_dir, exist_ok=True)
+    logging.debug(f"Using temporary directory: {temp_dir}")
+
+    try:
         for prediction, group_id, image_id, metadata in zip(
             prediction_data, group_ids, image_ids, image_metadata
         ):
             confidence, predicted_text = prediction
-            output_text = (f"{image_id}\t{metadata}\t{confidence}"
-                           f"\t{predicted_text}")
+            output_text = (
+                f"{image_id}\t{metadata}\t{confidence}\t{predicted_text}")
             output_texts.append(output_text)
 
             group_output_dir = os.path.join(base_output_path, group_id)
@@ -207,6 +218,11 @@ def save_prediction_outputs(
                 logging.error("Failed to write file %s. Error: %s",
                               output_file_path, e)
                 raise
+    finally:
+        # Clean up the temporary directory
+        if os.path.exists(temp_dir):
+            shutil.rmtree(temp_dir)
+            logging.debug(f"Cleaned up temporary directory: {temp_dir}")
 
     return output_texts
 
@@ -239,8 +255,7 @@ def write_file_atomically(content: str, target_path: str, temp_dir: str) \
             temp_file.write(content + "\n")
             temp_file_path = temp_file.name
 
-        # On POSIX systems, this is atomic. On Windows, it's the best we can
-        # do.
+        # On POSIX systems, this is atomic. On Windows, it's the best we can do
         os.replace(temp_file_path, target_path)
     except IOError as e:
         if temp_file_path and os.path.exists(temp_file_path):