From 9f24699e4c1e4cee507b5a5d6bd8b704962fc586 Mon Sep 17 00:00:00 2001
From: kerry <kerry@berri.ai>
Date: Sun, 20 Sep 2026 05:44:56 +0000
Subject: [PATCH] fix(fal_ai): reject empty image lists in image edit requests

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---
 litellm/llms/fal_ai/image_edit/transformation.py            | 6 +++---
 .../image_edit/test_fal_ai_image_edit_transformation.py     | 5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/litellm/llms/fal_ai/image_edit/transformation.py b/litellm/llms/fal_ai/image_edit/transformation.py
index 794d058bbd4..70b5d0612f2 100644
--- a/litellm/llms/fal_ai/image_edit/transformation.py
+++ b/litellm/llms/fal_ai/image_edit/transformation.py
@@ -138,9 +138,9 @@ class FalAIImageEditConfig(BaseImageEditConfig):
         litellm_params: GenericLiteLLMParams,
         headers: dict,
     ) -> tuple[dict, RequestFiles]:
-        if image is None:
+        images: Final = tuple(img for img in (image if isinstance(image, list) else (image,)) if img is not None)
+        if not images:
             raise ValueError("Fal AI image edit requires at least one input image")
-        images: Final = tuple(image) if isinstance(image, list) else (image,)
         mask: Final = _first(image_edit_optional_request_params.get("mask"))
         mask_field: Final[Mapping[str, str]] = (
             MappingProxyType({"mask_url": _to_data_url(mask)}) if mask is not None else MappingProxyType({})
@@ -152,7 +152,7 @@ class FalAIImageEditConfig(BaseImageEditConfig):
         )
         request_body: Final[dict[str, object]] = {  # mutable-ok: base class contract returns a dict
             "prompt": prompt,
-            "image_urls": tuple(_to_data_url(img) for img in images if img is not None),
+            "image_urls": tuple(_to_data_url(img) for img in images),
             **mask_field,
             **provider_params,
         }
diff --git a/tests/test_litellm/llms/fal_ai/image_edit/test_fal_ai_image_edit_transformation.py b/tests/test_litellm/llms/fal_ai/image_edit/test_fal_ai_image_edit_transformation.py
index 9f4637308e1..65b04e1f1b8 100644
--- a/tests/test_litellm/llms/fal_ai/image_edit/test_fal_ai_image_edit_transformation.py
+++ b/tests/test_litellm/llms/fal_ai/image_edit/test_fal_ai_image_edit_transformation.py
@@ -128,12 +128,13 @@ def test_transform_response_maps_fal_images():
     assert [image.url for image in response.data] == ["https://fal.media/out.png"]
 
 
-def test_transform_request_requires_an_image():
+@pytest.mark.parametrize("image", [None, []])
+def test_transform_request_requires_an_image(image):
     with pytest.raises(ValueError, match="input image"):
         FalAIImageEditConfig().transform_image_edit_request(
             model="openai/gpt-image-2.5/flare/edit",
             prompt="make it blue",
-            image=None,
+            image=image,
             image_edit_optional_request_params={},
             litellm_params=GenericLiteLLMParams(),
             headers={},