From 4d3c1998affa9249fbfdcd0c8157acaa991f9186 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Thu, 3 Sep 2026 10:50:23 -0700
Subject: [PATCH] fix(image_gen): report the requested output_format on
 gpt-image responses

---
 .../image_generation/gpt_transformation.py    |  2 +-
 .../test_gpt_transformation.py                | 38 +++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_litellm/llms/openai/image_generation/test_gpt_transformation.py

diff --git a/litellm/llms/openai/image_generation/gpt_transformation.py b/litellm/llms/openai/image_generation/gpt_transformation.py
index 05494c497ca..64244cfaeda 100644
--- a/litellm/llms/openai/image_generation/gpt_transformation.py
+++ b/litellm/llms/openai/image_generation/gpt_transformation.py
@@ -84,6 +84,6 @@ class GPTImageGenerationConfig(BaseImageGenerationConfig):
         # set optional params
         image_response.size = optional_params.get("size", "1024x1024")  # default is always 1024x1024
         image_response.quality = optional_params.get("quality", "high")  # always hd for dall-e-3
-        image_response.output_format = optional_params.get("response_format", "png")  # always png for dall-e-3
+        image_response.output_format = optional_params.get("output_format", "png")
 
         return image_response
diff --git a/tests/test_litellm/llms/openai/image_generation/test_gpt_transformation.py b/tests/test_litellm/llms/openai/image_generation/test_gpt_transformation.py
new file mode 100644
index 00000000000..de54713a570
--- /dev/null
+++ b/tests/test_litellm/llms/openai/image_generation/test_gpt_transformation.py
@@ -0,0 +1,38 @@
+from unittest.mock import MagicMock
+
+import httpx
+import pytest
+
+from litellm.llms.azure.image_generation.gpt_transformation import AzureGPTImageGenerationConfig
+from litellm.llms.openai.image_generation.gpt_transformation import GPTImageGenerationConfig
+from litellm.types.utils import ImageResponse
+
+
+@pytest.mark.parametrize("config", [GPTImageGenerationConfig(), AzureGPTImageGenerationConfig()])
+def test_transform_image_generation_response_reports_requested_output_format(config):
+    raw_response = httpx.Response(
+        status_code=200,
+        json={
+            "created": 1788457009,
+            "data": [{"b64_json": "/9j/4AAQSkZJRg=="}],
+            "output_format": "jpeg",
+            "background": "opaque",
+            "quality": "low",
+            "size": "1024x1024",
+        },
+        request=httpx.Request("POST", "https://api.openai.com/v1/images/generations"),
+    )
+
+    image_response = config.transform_image_generation_response(
+        model="gpt-image-2",
+        raw_response=raw_response,
+        model_response=ImageResponse(),
+        logging_obj=MagicMock(),
+        request_data={"prompt": "a red apple", "output_format": "jpeg"},
+        optional_params={"output_format": "jpeg"},
+        litellm_params={},
+        encoding=None,
+    )
+
+    assert image_response.output_format == "jpeg"
+    assert image_response.background == "opaque"