diff --git a/ais_bench/benchmark/datasets/utils/datasets.py b/ais_bench/benchmark/datasets/utils/datasets.py
index 6bb31701..41a6594e 100644
--- a/ais_bench/benchmark/datasets/utils/datasets.py
+++ b/ais_bench/benchmark/datasets/utils/datasets.py
@@ -23,7 +23,9 @@
     "ais_bench.benchmark.datasets.VocalSoundDataset",
 ]
 # Multimodal APIs.
-MM_APIS = ["ais_bench.benchmark.models.VLLMCustomAPIChat"]
+MM_APIS = ["ais_bench.benchmark.models.VLLMCustomAPIChat",
+           "ais_bench.benchmark.models.VLLMCustomAPIChatStream",
+]
 
 def get_cache_dir(default_dir):
     # TODO Add any necessary supplementary information for here
diff --git a/ais_bench/benchmark/utils/model_postprocessors.py b/ais_bench/benchmark/utils/model_postprocessors.py
index 34917705..ff90180d 100644
--- a/ais_bench/benchmark/utils/model_postprocessors.py
+++ b/ais_bench/benchmark/utils/model_postprocessors.py
@@ -1,152 +1,21 @@
 import re
-from functools import partial
-from multiprocessing import Pool
-from typing import Union
-
-from tqdm import tqdm
 
 from ais_bench.benchmark.registry import TEXT_POSTPROCESSORS
-
-from ais_bench.benchmark.utils.postprocess.postprocessors.naive import NaiveExtractor, format_input_naive
-from ais_bench.benchmark.utils.postprocess.postprocessors.xfinder.extractor import Extractor
 from ais_bench.benchmark.utils.logging.logger import AISLogger
-from ais_bench.benchmark.utils.postprocess.postprocessors.xfinder.xfinder_utils import (DataProcessor,
-                                                   convert_to_xfinder_format)
 
 
 logger = AISLogger()
 logger.warning("ais_bench.benchmark.utils.model_postprocessors is deprecated, please use ais_bench.benchmark.utils.postprocess.model_postprocessors instead.")
 
-def gen_output_naive(ori_data, extractor):
-    extracted_answers = []
-    for item in tqdm(ori_data):
-        user_input = extractor.prepare_input(item)
-        extracted_answer = extractor.gen_output(user_input)
-        item['extracted_answer'] = extracted_answer
-        extracted_answers.append(extracted_answer)
-
-    return extracted_answers
-
-
-@TEXT_POSTPROCESSORS.register_module('naive')
-def naive_model_postprocess(preds: list,
-                            model_name: str,
-                            custom_instruction: str,
-                            api_url: Union[str, list],
-                            num_processes: int = 8,
-                            **kwargs) -> list:
-    """Postprocess the text extracted by custom model.
-    Args:
-        preds (list): The question, reference answer and model prediction.
-        model_name (str): The name of the model.
-        custom_instruction (str): Custom instruction for the dataset.
-        url (Union[str, list]): The api url of the model.
-
-    Returns:
-        list: The postprocessed answers.
-    """
-
-    def _eval_pred(texts, extractor, num_processes):
-        ori_data = texts
-        extracted_answers = []
-        batched_ori_data = []
-        # Split data into batches
-        num_processes = min(num_processes, len(ori_data))
-        batch_size = len(ori_data) // num_processes
-        for i in range(0, len(ori_data), batch_size):
-            batched_ori_data.append(ori_data[i:i + batch_size])
-        with Pool(num_processes) as p:
-            results = p.map(partial(gen_output_naive, extractor=extractor),
-                            batched_ori_data)
-            for result in results:
-                extracted_answers.extend(result)
-        return extracted_answers
-
-    format_data = format_input_naive(preds)
-    assert api_url is not None, 'Please provide the api url.'
-    extractor = NaiveExtractor(
-        model_name=model_name,
-        custom_instruction=custom_instruction,
-        url=api_url.split(',') if ',' in api_url else api_url)
-    calc_acc_func = partial(_eval_pred,
-                            extractor=extractor,
-                            num_processes=num_processes)
-    extracted_answers = calc_acc_func(format_data)
-    return extracted_answers
-
-
-def gen_output_xfinder(ori_data, extractor):
-    ext_cor_pairs = []
-    extracted_data = []
-    extracted_answers = []
-    for item in tqdm(ori_data):
-        user_input = extractor.prepare_input(item)
-        extracted_answer = extractor.gen_output(user_input)
-        ext_cor_pairs.append([
-            item['key_answer_type'], item['standard_answer_range'],
-            extracted_answer, item['correct_answer']
-        ])
-        item['xfinder_extracted_answer'] = extracted_answer
-        extracted_answers.append(extracted_answer)
-        extracted_data.append(item)
-
-    return extracted_answers, ext_cor_pairs, extracted_data
-
-
-@TEXT_POSTPROCESSORS.register_module('xfinder')
-def xfinder_postprocess(preds: list, question_type: str, model_name: str,
-                        api_url: Union[str, list], **kwargs) -> list:
-    """Postprocess the text extracted by xFinder model.
-    Args:
-        preds (list): The question, reference answer and model prediction.
-        question_type (str): The type of the question.
-        url (Union[str, list]): The api url of the xFinder model.
-
-
-    Returns:
-        list: The postprocessed texts.
-    """
-
-    def _eval_pred(texts, data_processor, extractor, num_processes=8):
-        ori_data = data_processor.read_data(texts)
-        extracted_correct_pairs = []
-        extracted_data = []
-        extracted_answers = []
-        batched_ori_data = []
-        # Split data into batches
-        num_processes = min(num_processes, len(ori_data))
-        batch_size = len(ori_data) // num_processes
-        for i in range(0, len(ori_data), batch_size):
-            batched_ori_data.append(ori_data[i:i + batch_size])
-        with Pool(num_processes) as p:
-            results = p.map(partial(gen_output_xfinder, extractor=extractor),
-                            batched_ori_data)
-        for result in results:
-            extracted_answers += result[0]
-            extracted_correct_pairs += result[1]
-            extracted_data += result[2]
-        return extracted_answers
-
-    format_data = convert_to_xfinder_format(question_type, preds)
-    assert api_url is not None, 'Please provide the api url.'
-    data_processor = DataProcessor()
-    extractor = Extractor(
-        model_name=model_name,
-        url=api_url.split(',') if ',' in api_url else api_url)
-    calc_acc_func = partial(_eval_pred,
-                            data_processor=data_processor,
-                            extractor=extractor)
-    extracted_answers = calc_acc_func(format_data)
-    return extracted_answers
-
 
 def list_decorator(func):
     """Decorator: make the function able to handle list input"""
     def wrapper(text_or_list, *args, **kwargs):
         if isinstance(text_or_list, list):
+            logger.debug(f"list_decorator({func.__name__}): processing list of {len(text_or_list)} item(s)")
             return [func(text, *args, **kwargs) for text in text_or_list]
-        else:
-            return func(text_or_list, *args, **kwargs)
+        logger.debug(f"list_decorator({func.__name__}): processing single item")
+        return func(text_or_list, *args, **kwargs)
     return wrapper
 
 
@@ -180,20 +49,24 @@ def extract_non_reasoning_content(
         >>> text = "Start<think>reasoning here</think> End"
         >>> extract_non_reasoning_content(text)
         'Start End'
-        
+
         >>> # When input is a list
         >>> texts = ["Start<think>reasoning</think> End", "Test</think> Result"]
         >>> extract_non_reasoning_content(texts)
         ['Start End', 'Result']
     """
+    logger.debug(f"extract_non_reasoning_content: start_token='{think_start_token}', end_token='{think_end_token}'")
     # If text contains only end token, split by end token and take the last part
     if not isinstance(text, str):
         return text
     if think_start_token not in text and think_end_token in text:
-        return text.split(think_end_token)[-1].strip()
+        result = text.split(think_end_token)[-1].strip()
+        logger.debug(f"extract_non_reasoning_content: only end token present -> length={len(result)}")
+        return result
 
     # Original behavior for complete tag pairs
     reasoning_regex = re.compile(rf'{think_start_token}(.*?){think_end_token}',
                                  re.DOTALL)
     non_reasoning_content = reasoning_regex.sub('', text).strip()
-    return non_reasoning_content
\ No newline at end of file
+    logger.debug(f"extract_non_reasoning_content: removed reasoning sections -> length={len(non_reasoning_content)}")
+    return non_reasoning_content
diff --git a/tests/UT/utils/test_model_postprocessors.py b/tests/UT/utils/test_model_postprocessors.py
index be10136b..ebaf122c 100644
--- a/tests/UT/utils/test_model_postprocessors.py
+++ b/tests/UT/utils/test_model_postprocessors.py
@@ -41,131 +41,6 @@ def setUp(self):
             }
         ]
 
-    @patch('ais_bench.benchmark.utils.model_postprocessors.Pool')
-    @patch('ais_bench.benchmark.utils.model_postprocessors.NaiveExtractor')
-    @patch('ais_bench.benchmark.utils.model_postprocessors.format_input_naive')
-    def test_naive_model_postprocess(self, mock_format, mock_extractor_class, mock_pool):
-        """Test naive_model_postprocess function."""
-        # Setup mocks
-        mock_format.return_value = self.test_preds
-        mock_extractor = MagicMock()
-        mock_extractor_class.return_value = mock_extractor
-
-        # Mock the extractor's methods
-        def mock_gen_output(ori_data, extractor):
-            results = []
-            for item in ori_data:
-                extracted = extractor.gen_output(item)
-                results.append(extracted)
-            return results
-
-        mock_extractor.prepare_input.return_value = "prepared_input"
-        mock_extractor.gen_output.return_value = "extracted_answer"
-
-        # Mock Pool
-        mock_pool_instance = MagicMock()
-        mock_pool.return_value.__enter__.return_value = mock_pool_instance
-        mock_pool.return_value.__exit__.return_value = False
-
-        # Mock map to call the function directly
-        def mock_map(func, batches):
-            results = []
-            for batch in batches:
-                batch_result = func(batch)
-                results.append(batch_result)
-            return results
-
-        mock_pool_instance.map = mock_map
-
-        # Call the function
-        result = mp.naive_model_postprocess(
-            preds=self.test_preds,
-            model_name="test_model",
-            custom_instruction="Extract the answer",
-            api_url="http://test.api",
-            num_processes=2
-        )
-
-        # Verify
-        self.assertIsInstance(result, list)
-        self.assertEqual(len(result), 2)
-        mock_format.assert_called_once_with(self.test_preds)
-        mock_extractor_class.assert_called_once()
-
-    @patch('ais_bench.benchmark.utils.model_postprocessors.Pool')
-    @patch('ais_bench.benchmark.utils.model_postprocessors.Extractor')
-    @patch('ais_bench.benchmark.utils.model_postprocessors.DataProcessor')
-    @patch('ais_bench.benchmark.utils.model_postprocessors.convert_to_xfinder_format')
-    def test_xfinder_postprocess(self, mock_convert, mock_data_processor_class,
-                                 mock_extractor_class, mock_pool):
-        """Test xfinder_postprocess function."""
-        # Setup mocks
-        mock_convert.return_value = self.test_preds
-        mock_data_processor = MagicMock()
-        mock_data_processor_class.return_value = mock_data_processor
-        mock_data_processor.read_data.return_value = [
-            {
-                'key_answer_type': 'number',
-                'standard_answer_range': '0-10',
-                'correct_answer': '4'
-            }
-        ]
-
-        mock_extractor = MagicMock()
-        mock_extractor_class.return_value = mock_extractor
-        mock_extractor.prepare_input.return_value = "prepared_input"
-        mock_extractor.gen_output.return_value = "extracted_answer"
-
-        # Mock Pool
-        mock_pool_instance = MagicMock()
-        mock_pool.return_value.__enter__.return_value = mock_pool_instance
-        mock_pool.return_value.__exit__.return_value = False
-
-        def mock_map(func, batches):
-            results = []
-            for batch in batches:
-                batch_result = func(batch)
-                results.append(batch_result)
-            return results
-
-        mock_pool_instance.map = mock_map
-
-        # Call the function
-        result = mp.xfinder_postprocess(
-            preds=self.test_preds,
-            question_type="math",
-            model_name="test_model",
-            api_url="http://test.api"
-        )
-
-        # Verify
-        self.assertIsInstance(result, list)
-        mock_convert.assert_called_once()
-        mock_data_processor_class.assert_called_once()
-        mock_extractor_class.assert_called_once()
-
-    def test_naive_model_postprocess_no_api_url(self):
-        """Test naive_model_postprocess raises error when api_url is None."""
-        with self.assertRaises(AssertionError) as cm:
-            mp.naive_model_postprocess(
-                preds=self.test_preds,
-                model_name="test_model",
-                custom_instruction="Extract",
-                api_url=None
-            )
-        self.assertIn("api url", str(cm.exception).lower())
-
-    def test_xfinder_postprocess_no_api_url(self):
-        """Test xfinder_postprocess raises error when api_url is None."""
-        with self.assertRaises(AssertionError) as cm:
-            mp.xfinder_postprocess(
-                preds=self.test_preds,
-                question_type="math",
-                model_name="test_model",
-                api_url=None
-            )
-        self.assertIn("api url", str(cm.exception).lower())
-
     def test_list_decorator_with_list(self):
         """Test list_decorator with list input."""
         @mp.list_decorator