From 2622a0634a4f8c59db87ac307923063202a6b72b Mon Sep 17 00:00:00 2001
From: Ivan Krakhmaliuk <LifeDJIK@users.noreply.github.com>
Date: Mon, 1 Sep 2025 19:51:54 +0300
Subject: [PATCH 1/2] GPT-5: Remove params unsupported with reasoning models

---
 litellm/llms/openai/chat/gpt_5_transformation.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/litellm/llms/openai/chat/gpt_5_transformation.py b/litellm/llms/openai/chat/gpt_5_transformation.py
index 9a8bb74d447..3902304a3b4 100644
--- a/litellm/llms/openai/chat/gpt_5_transformation.py
+++ b/litellm/llms/openai/chat/gpt_5_transformation.py
@@ -28,7 +28,18 @@ class OpenAIGPT5Config(OpenAIGPTConfig):
         base_gpt_series_params.extend(gpt_5_only_params)
         if not supports_tool_choice(model=model):
             base_gpt_series_params.remove("tool_choice")
-        return base_gpt_series_params
+
+        non_supported_params = [
+            "logprobs",
+            "top_p",
+            "presence_penalty",
+            "frequency_penalty",
+            "top_logprobs",
+        ]
+
+        return [
+            param for param in base_gpt_series_params if param not in non_supported_params
+        ]
 
     def map_openai_params(
         self,

From 76dd9d81100dbda65384cb6030c9c63fc0f676ee Mon Sep 17 00:00:00 2001
From: Ivan Krakhmaliuk <Ivan_Krakhmaliuk@epam.com>
Date: Mon, 1 Sep 2025 20:30:43 +0300
Subject: [PATCH 2/2] GPT-5: Test for unsupported params

---
 .../llms/openai/test_gpt5_transformation.py           | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tests/test_litellm/llms/openai/test_gpt5_transformation.py b/tests/test_litellm/llms/openai/test_gpt5_transformation.py
index 3bdab355977..3e6a6a23468 100644
--- a/tests/test_litellm/llms/openai/test_gpt5_transformation.py
+++ b/tests/test_litellm/llms/openai/test_gpt5_transformation.py
@@ -41,3 +41,14 @@ def test_gpt5_temperature_error(config: OpenAIConfig):
             model="gpt-5",
             drop_params=False,
         )
+
+
+def test_gpt5_unsupported_params_drop(config: OpenAIConfig):
+    assert "top_p" not in config.get_supported_openai_params(model="gpt-5")
+    params = config.map_openai_params(
+        non_default_params={"top_p": 0.5},
+        optional_params={},
+        model="gpt-5",
+        drop_params=True,
+    )
+    assert "top_p" not in params