Invalid request leads to 500 error instead of 400

[adubovik]

The error is reproducible for deployments declared in GPT4O_DEPLOYMENTS:

Request:

curl http://localhost:5006/openai/deployments/gpt-4o/chat/completions \
  -H "Content-Type: application/json" \
  -H "api-key:dummy" \
  -H "X-UPSTREAM-ENDPOINT:http://localhost:5007/openai/deployments/gpt-4o/chat/completions" \
  -H "X-UPSTREAM-KEY:dummy" \
  -d '{
    "model": "gpt-4o",
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "text",
            "text": "What is in this image?"
          },
          {
            "type": "image_url",
            "image_url": "https://en.wikipedia.org/static/images/icons/wikipedia.png"
          }
        ]
      }
    ]
  }'

Response:

< HTTP/1.1 500 Internal Server Error
< date: Mon, 21 Jul 2025 12:35:34 GMT
< server: uvicorn
< content-length: 21
< content-type: text/plain; charset=utf-8
< 
* Connection #0 to host localhost left intact
Internal Server Error

Stack trace:

  File "aidial_adapter_openai/endpoints/chat_completion.py", line 174, in chat_completion
    await call_chat_completion(
  File "aidial_adapter_openai/endpoints/chat_completion.py", line 130, in call_chat_completion
    return await gpt4o_chat_completion(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "aidial_adapter_openai/gpt4_multi_modal/chat_completion.py", line 102, in gpt4o_chat_completion
    transform_result = await ResourceProcessor(
                       ^^^^^^^^^^^^^^^^^^^^^^^^
  File "aidial_adapter_openai/gpt4_multi_modal/transformation.py", line 150, in transform_messages
    transformations = [
                      ^
  File "aidial_adapter_openai/gpt4_multi_modal/transformation.py", line 151, in <listcomp>
    await self.transform_message(message) for message in messages
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "aidial_adapter_openai/gpt4_multi_modal/transformation.py", line 127, in transform_message
    content_meta = await self.download_content_images(content)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "aidial_adapter_openai/gpt4_multi_modal/transformation.py", line 104, in download_content_images
    if image_url and (url := image_url.get("url")):
                             ^^^^^^^^^^^^^
AttributeError: 'str' object has no attribute 'get'