diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index 64f90048493..27d3b9e912a 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -30727,7 +30727,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30747,7 +30746,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30767,7 +30765,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30835,7 +30832,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-code-fast-1": {
@@ -30849,7 +30845,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-code-fast-1-0825": {
@@ -30863,7 +30858,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-vision-beta": {
diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index 64f90048493..27d3b9e912a 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -30727,7 +30727,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30747,7 +30746,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30767,7 +30765,6 @@
         "source": "https://docs.x.ai/docs/models/grok-4-1-fast-reasoning",
         "supports_audio_input": true,
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_response_schema": true,
         "supports_tool_choice": true,
         "supports_vision": true,
@@ -30835,7 +30832,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-code-fast-1": {
@@ -30849,7 +30845,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-code-fast-1-0825": {
@@ -30863,7 +30858,6 @@
         "output_cost_per_token": 1.5e-06,
         "source": "https://docs.x.ai/docs/models",
         "supports_function_calling": true,
-        "supports_reasoning": true,
         "supports_tool_choice": true
     },
     "xai/grok-vision-beta": {
diff --git a/tests/test_litellm/llms/xai/chat/test_xai_chat_transformation.py b/tests/test_litellm/llms/xai/chat/test_xai_chat_transformation.py
new file mode 100644
index 00000000000..00d563b7e71
--- /dev/null
+++ b/tests/test_litellm/llms/xai/chat/test_xai_chat_transformation.py
@@ -0,0 +1,40 @@
+"""
+Tests for XAI Chat API transformation.
+
+Source: litellm/llms/xai/chat/transformation.py
+"""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.abspath("../../../../../.."))
+
+import pytest
+
+from litellm.llms.xai.chat.transformation import XAIChatConfig
+
+
+class TestXAIChatTransformation:
+    def test_grok_3_mini_supports_reasoning_effort(self):
+        config = XAIChatConfig()
+
+        supported_params = config.get_supported_openai_params(model="grok-3-mini")
+
+        assert "reasoning_effort" in supported_params
+
+    @pytest.mark.parametrize(
+        "model",
+        [
+            "grok-3",
+            "grok-4",
+            "grok-4-fast-reasoning",
+            "grok-4-1-fast-reasoning",
+            "grok-4-1-fast-non-reasoning",
+        ],
+    )
+    def test_reasoning_effort_excluded_for_other_grok_models(self, model: str):
+        config = XAIChatConfig()
+
+        supported_params = config.get_supported_openai_params(model=model)
+
+        assert "reasoning_effort" not in supported_params