From 75dd70a67829c89a7d9a446c2781f8278df22d30 Mon Sep 17 00:00:00 2001
From: Deepanshu <deepanshu.lulla@alpha-sense.com>
Date: Tue, 30 Jun 2026 17:08:04 -0400
Subject: [PATCH] fix(model_cost): add supports_reasoning: false to Gemini
 image generation models

vertex_ai/gemini-2.5-flash-image, vertex_ai/gemini-3-pro-image-preview,
vertex_ai/gemini-3.1-flash-image-preview, gemini/gemini-3-pro-image-preview,
and gemini/gemini-3.1-flash-image-preview were missing supports_reasoning
entries; _supports_factory then fell through to the vertex_ai provider-level
config which returns true, causing requests with reasoning_effort to be sent
to an API that rejects them.
---
 ...odel_prices_and_context_window_backup.json |  5 +++++
 tests/test_litellm/test_utils.py              | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index 2a269d693ec..1f1bec02f9c 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -18727,6 +18727,7 @@
         ],
         "supports_function_calling": false,
         "supports_prompt_caching": true,
+        "supports_reasoning": false,
         "supports_response_schema": true,
         "supports_system_messages": true,
         "supports_vision": true,
@@ -18768,6 +18769,7 @@
         ],
         "supports_function_calling": false,
         "supports_prompt_caching": true,
+        "supports_reasoning": false,
         "supports_response_schema": true,
         "supports_system_messages": true,
         "supports_vision": true,
@@ -36726,6 +36728,7 @@
         "supports_parallel_function_calling": true,
         "supports_pdf_input": true,
         "supports_prompt_caching": true,
+        "supports_reasoning": false,
         "supports_response_schema": true,
         "supports_system_messages": true,
         "supports_tool_choice": true,
@@ -36748,6 +36751,7 @@
         "output_cost_per_image_token": 0.00012,
         "output_cost_per_token": 1.2e-05,
         "output_cost_per_token_batches": 6e-06,
+        "supports_reasoning": false,
         "source": "https://docs.cloud.google.com/vertex-ai/generative-ai/docs/models/gemini/3-pro-image"
     },
     "vertex_ai/gemini-3.1-flash-image-preview": {
@@ -36761,6 +36765,7 @@
         "output_cost_per_image": 0.0672,
         "output_cost_per_image_token": 6e-05,
         "output_cost_per_token": 3e-06,
+        "supports_reasoning": false,
         "source": "https://cloud.google.com/vertex-ai/generative-ai/pricing#gemini-models"
     },
     "vertex_ai/gemini-3.1-flash-lite-preview": {
diff --git a/tests/test_litellm/test_utils.py b/tests/test_litellm/test_utils.py
index d739f9c116a..e05a69f01c8 100644
--- a/tests/test_litellm/test_utils.py
+++ b/tests/test_litellm/test_utils.py
@@ -4709,3 +4709,22 @@ class TestValidateEnvironmentTencent:
         assert "TENCENT_API_KEY" in result["missing_keys"]
 
 
+
+@pytest.mark.parametrize(
+    "model",
+    [
+        "vertex_ai/gemini-2.5-flash-image",
+        "vertex_ai/gemini-3-pro-image-preview",
+        "vertex_ai/gemini-3.1-flash-image-preview",
+        "gemini/gemini-2.5-flash-image",
+        "gemini/gemini-3-pro-image-preview",
+        "gemini/gemini-3.1-flash-image-preview",
+    ],
+)
+def test_gemini_image_models_do_not_support_reasoning(
+    model: str, local_model_cost_map: None
+) -> None:
+    assert litellm.supports_reasoning(model) is False, (
+        f"{model} incorrectly classified as reasoning-capable. "
+        "Add 'supports_reasoning: false' to its model_cost entry."
+    )