diff --git a/amqp/adapter/cleverthis_service_adapter.py b/amqp/adapter/cleverthis_service_adapter.py
index 9eab27c..6c43f37 100644
--- a/amqp/adapter/cleverthis_service_adapter.py
+++ b/amqp/adapter/cleverthis_service_adapter.py
@@ -495,12 +495,11 @@ class CleverThisServiceAdapter:
                 if self.authenticated_user_arg_name in _signature_args.keys():
                     _args[self.authenticated_user_arg_name] = auth_user
                 # If the path matches, call the corresponding function
-                return await CleverThisServiceAdapter.call_cleverthis_api(
+                return await self.call_cleverthis_api(
                     message,
                     _args,
                     api_method=_route.endpoint,
                     success_code=_route.status_code,
-                    loop=self.loop,
                 )
 
         return DataResponseFactory.of(
@@ -566,12 +565,11 @@ class CleverThisServiceAdapter:
                 if self.authenticated_user_arg_name in _signature_args.keys():
                     _verified_args[self.authenticated_user_arg_name] = auth_user
 
-                return await CleverThisServiceAdapter.call_cleverthis_api(
+                return await self.call_cleverthis_api(
                     message,
                     _verified_args,
                     api_method=_route.endpoint,
                     success_code=_route.status_code if _route.status_code else 200,
-                    loop=self.loop,
                 )
 
         return DataResponseFactory.of(
@@ -582,28 +580,21 @@ class CleverThisServiceAdapter:
             message.trace_info(),
         )
 
-    @staticmethod
-    async def call_cleverthis_api(
-        message: AMQMessage,
+    def _verify_and_instantiate_arguments(
+        self,
         args: Any,
         api_method: Callable[[Any, Any], Coroutine],
-        success_code: int,
-        loop: AbstractEventLoop | None = None,
-    ) -> DataResponse:
+    ) -> dict:
         """
-        Handles POST and PUT requests, which typically contain possibly complex payload data,
-        passed as a dictionary. Invokes the provided API method with the given arguments and
-        authenticated user, and returns the response as DataResponse.
+        Check the provided arguments against the API method signature and convert the incoming string value
+        into correct expected input object.
+        The logic used FastAPI annotation and would use the value from 'default_factory' invocation (where defined)
+        or 'default' value, as defined in the FastAPI annotation, to create default value in case the object is not in
+        the input values provided by the caller.
 
-        :param message: DataMessage containing the details of the call and the payload
-        :param args: map of the arguments to pass to the API method
-        :param api_method: Callable - the method to invoke. Last parameter is the authenticated user
-        :param success_code: HTTP code to be returned when operation suceeds
-
-        :return: DataResponse class
         """
+        _verified_args = {}
         try:
-            _verified_args = {}
             _sig = inspect.signature(api_method)
             _required_args = list(_sig.parameters.values())
             # _required_args = getattr(api_method, '__annotations__', {})
@@ -612,7 +603,9 @@ class CleverThisServiceAdapter:
                     _annotation = arg.annotation
                     _str_annotation = str(_annotation)
                     # convert to another type_string if arg is not a str
-                    if _annotation == int:
+                    if arg.name == self.authenticated_user_arg_name:
+                        _verified_args[arg.name] = args.get(arg.name)
+                    elif _annotation == int:
                         _verified_args[arg.name] = int(args.get(arg.name))
                     elif _annotation == float:
                         _verified_args[arg.name] = float(args.get(arg.name))
@@ -656,7 +649,7 @@ class CleverThisServiceAdapter:
                 else:
                     if hasattr(arg, "default"):
                         _temp = arg.default
-                        if hasattr(_temp, "default_factory"):
+                        if hasattr(_temp, "default_factory") and _temp.default_factory is not None:
                             _temp = _temp.default_factory()
                         elif hasattr(_temp, "default"):
                             _temp = _temp.default
@@ -665,6 +658,33 @@ class CleverThisServiceAdapter:
                         logging_warning(
                             f"{api_method.__name__}: Missing required argument: {arg.name}"
                         )
+        except Exception as unchecked:
+            logging_error("Failed to validate and instantiate input args", unchecked)
+        return _verified_args
+
+    async def call_cleverthis_api(
+        self,
+        message: AMQMessage,
+        args: Any,
+        api_method: Callable[[Any, Any], Coroutine],
+        success_code: int,
+    ) -> DataResponse:
+        """
+        Handles POST and PUT requests, which typically contain possibly complex payload data,
+        passed as a dictionary. Invokes the provided API method with the given arguments and
+        authenticated user, and returns the response as DataResponse.
+
+        :param message: DataMessage containing the details of the call and the payload
+        :param args: map of the arguments to pass to the API method
+        :param api_method: Callable - the method to invoke. Last parameter is the authenticated user
+        :param success_code: HTTP code to be returned when operation suceeds
+
+        :return: DataResponse class
+        """
+        try:
+            _verified_args = self._verify_and_instantiate_arguments(
+                args=args, api_method=api_method
+            )
             logging_info(
                 "INVOKE ENDPOINT: {%s}, ARGS: {%s}",
                 api_method.__name__,
@@ -679,7 +699,7 @@ class CleverThisServiceAdapter:
                         _result,
                         message.connection,
                         file_handler=StreamingFileHandler(),
-                        loop=loop,
+                        loop=self.loop,
                     ),
                     "application/octet-stream",
                 )
diff --git a/amqp/adapter/data_parser.py b/amqp/adapter/data_parser.py
index 8ae28fd..c1a8be4 100644
--- a/amqp/adapter/data_parser.py
+++ b/amqp/adapter/data_parser.py
@@ -149,7 +149,7 @@ class AMQDataParser:
         # Parse JSON
         if content_type == "application/json":
             try:
-                return json.loads(message.body())
+                return json.loads(message.body() or "{}")
             except json.JSONDecodeError as e:
                 logging_error(f"Invalid JSON: {e}")
                 raise ValueError(f"Invalid JSON: {e}")
diff --git a/pyproject.toml b/pyproject.toml
index 36d8b7f..79de392 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "amq_adapter"
-version = "0.2.32"
+version = "0.2.33"
 description = "The Python implementation of the AMQ Adapter for CleverMicro"
 readme = "README.md"
 authors = [