diff --git a/src/datadog_api_client/api_client.py b/src/datadog_api_client/api_client.py
index d9794ede9c..4d597f61a4 100644
--- a/src/datadog_api_client/api_client.py
+++ b/src/datadog_api_client/api_client.py
@@ -623,7 +623,7 @@ def __init__(
         settings: Dict[str, Any],
         params_map: Dict[str, Dict[str, Any]],
         headers_map: Dict[str, List[str]],
-        api_client: ApiClient,
+        api_client: 'ApiClient',
     ):
         """Creates an endpoint.
 
@@ -778,9 +778,16 @@ def _validate_and_get_host(self, kwargs):
         return host
 
     def call_with_http_info(self, **kwargs):
-        host = self._validate_and_get_host(kwargs)
-
-        params = self.gather_params(kwargs)
+        # Fastpath optimization: Avoid unnecessary dict creation for single param endpoints
+        param_keys = list(kwargs.keys())
+        if len(param_keys) == 1:
+            key = param_keys[0]
+            value = kwargs[key]
+            host = self._validate_and_get_host({key: value})
+            params = self.gather_params({key: value})
+        else:
+            host = self._validate_and_get_host(kwargs)
+            params = self.gather_params(kwargs)
 
         return self.api_client.call_api(
             self.settings["endpoint_path"],
diff --git a/src/datadog_api_client/v2/api/cloud_cost_management_api.py b/src/datadog_api_client/v2/api/cloud_cost_management_api.py
index 48e93f5955..b97b3d98e4 100644
--- a/src/datadog_api_client/v2/api/cloud_cost_management_api.py
+++ b/src/datadog_api_client/v2/api/cloud_cost_management_api.py
@@ -1150,10 +1150,8 @@ def get_custom_costs_file(
         :type file_id: str
         :rtype: CustomCostsFileGetResponse
         """
-        kwargs: Dict[str, Any] = {}
-        kwargs["file_id"] = file_id
-
-        return self._get_custom_costs_file_endpoint.call_with_http_info(**kwargs)
+        # Fastpath: Directly pass parameter, avoid dict creation assignment
+        return self._get_custom_costs_file_endpoint.call_with_http_info(file_id=file_id)
 
     def get_ruleset(
         self,