fix(images): forward image_config on OpenRouter image edits

image_config was honored on OpenRouter image generation but silently dropped on image edits.
The default edit branch in image_edit() never merged non_default_params (which still carries
image_config after the optional-param whitelist filters it out) before calling the handler,
unlike the bedrock, stability, and black_forest_labs branches. Merge non_default_params for the
openrouter path so image_config survives; OpenRouter's transform already forwards extra
top-level params into the chat-completions body, so it then reaches the provider

Fixes #30753

litellm/images/main.py

@@ -963,6 +963,8 @@ def image_edit(
                 client=kwargs.get("client"),
                 aimage_edit=_is_async,
             )
+        if custom_llm_provider == "openrouter":
+            image_edit_request_params.update(non_default_params)
         # Call the handler with _is_async flag instead of directly calling the async handler
         return base_llm_http_handler.image_edit_handler(
             model=model,

tests/test_litellm/images/test_image_edit_utils.py

@@ -269,6 +269,60 @@ class TestImageEditCustomPricing:
         assert use_custom_pricing_for_model(litellm_params) is False
 
 
+class TestImageEditOpenRouterImageConfig:
+    """
+    Regression test for https://github.com/BerriAI/litellm/issues/30753
+
+    image_config is honored on OpenRouter image generation but was silently dropped on
+    image edits: the default edit path never merged non_default_params (which still carries
+    image_config) before calling the handler, unlike the bedrock/stability/black_forest_labs
+    branches. OpenRouter's transform forwards extra top-level params, so once image_config
+    survives the merge it reaches the provider.
+    """
+
+    def test_openrouter_image_edit_forwards_image_config(self):
+        from litellm.images.main import image_edit
+
+        image_config = {"aspect_ratio": "16:9", "image_size": "2K"}
+
+        with (
+            patch(
+                "litellm.images.main.get_llm_provider",
+                return_value=(
+                    "google/gemini-3-pro-image-preview",
+                    "openrouter",
+                    None,
+                    None,
+                ),
+            ),
+            patch(
+                "litellm.images.main.ProviderConfigManager.get_provider_image_edit_config",
+                return_value=MagicMock(),
+            ),
+            patch(
+                "litellm.images.main._get_ImageEditRequestUtils",
+                return_value=MagicMock(
+                    get_requested_image_edit_optional_param=MagicMock(return_value={}),
+                    get_optional_params_image_edit=MagicMock(return_value={}),
+                ),
+            ),
+            patch("litellm.images.main.base_llm_http_handler") as mock_handler,
+        ):
+            mock_handler.image_edit_handler.return_value = MagicMock()
+
+            image_edit(
+                image=b"fake-image-data",
+                prompt="add a red border",
+                model="openrouter/google/gemini-3-pro-image-preview",
+                image_config=image_config,
+            )
+
+        forwarded = mock_handler.image_edit_handler.call_args.kwargs[
+            "image_edit_optional_request_params"
+        ]
+        assert forwarded.get("image_config") == image_config
+
+
 class TestImageEditHandlerCredentialsForwarding:
     """
     Regression tests for Vertex AI image_edit credentials bug.