fix(cloudflare): keep image parts when flattening message content

Flattening content parts to a string keeps only the text, so a message with an image_url would lose its image on vision models like llama-3.2-11b-vision-instruct. Skip the flatten when any message carries an image or audio part, using the existing audio_or_image_in_message_content helper.

litellm/llms/cloudflare/chat/transformation.py

@@ -5,6 +5,7 @@ import httpx
 
 from litellm._logging import verbose_logger
 from litellm.litellm_core_utils.prompt_templates.common_utils import (
+    audio_or_image_in_message_content,
     handle_messages_with_content_list_to_str_conversion,
 )
 from litellm.litellm_core_utils.url_utils import join_api_base
@@ -113,7 +114,9 @@ class CloudflareChatConfig(OpenAIGPTConfig):
         model: str,
         is_async: bool = False,
     ) -> list[AllMessageValues] | Coroutine[object, object, list[AllMessageValues]]:  # mutable-ok: base signature
-        flattened: Final = handle_messages_with_content_list_to_str_conversion(messages)
+        # Flattening keeps only the text, so skip it when any message carries an image or audio part
+        has_media: Final = any(audio_or_image_in_message_content(message) for message in messages)
+        flattened: Final = messages if has_media else handle_messages_with_content_list_to_str_conversion(messages)
         if is_async:
             return super()._transform_messages(messages=flattened, model=model, is_async=True)
         return super()._transform_messages(messages=flattened, model=model, is_async=False)

tests/unit/llms/cloudflare/test_cloudflare_transformation.py

@@ -246,6 +246,24 @@ def test_transform_request_leaves_string_content_untouched():
     assert [m["content"] for m in body["messages"]] == ["you are terse", "weather in nyc?"]
 
 
+def test_transform_request_does_not_flatten_when_a_part_is_not_text():
+    config = CloudflareChatConfig()
+    parts = [
+        {"type": "text", "text": "What is in this picture?"},
+        {"type": "image_url", "image_url": {"url": "https://example.com/cat.png"}},
+    ]
+
+    body = config.transform_request(
+        model="@cf/meta/llama-3.2-11b-vision-instruct",
+        messages=[{"role": "user", "content": parts}],
+        optional_params={},
+        litellm_params={},
+        headers={},
+    )
+
+    assert body["messages"][0]["content"] == parts
+
+
 def test_async_transform_request_flattens_content_part_arrays_to_string():
     config = CloudflareChatConfig()
     messages = [