400 Invalid JSON payload while sending an image message to Google Gemini 1.5 model

[nimish-gupta]

Description

We encountered an issue when sending an image as part of a message to the Google Gemini 1.5 Flash model using the Braintrust Proxy. The request fails with the following error:

400 Invalid JSON payload received. 
Unknown name "text" at 'contents[1].parts[0]': Proto field is not repeating, cannot start list.

Steps to Reproduce:

1. Set up the Braintrust Proxy with Google Gemini 1.5 Flash API using the following code snippet:

const client = new OpenAI({
  baseURL: "https://api.braintrust.dev/v1/proxy",
  apiKey: process.env.BRAINTRUST_API_KEY,
});

const response = await client.chat.completions.create({
  model: "gemini-1.5-flash-latest",
  messages: [
    { role: "user", content: "What do you think of this image?" },
    { role: "user", content: [{ type: "image_url", image_url: { url: "https://example.com/image.jpg" } }] }
  ],
});
console.log(response);

2. The request fails with the 400 error mentioned above.

Expected Behaviour:

1. The message containing the image should be processed successfully by the Gemini 1.5 Flash model via the Braintrust Proxy.
2. The API should return a valid response describing the image or engaging with the user prompt accordingly.

Impact:

1. This issue blocks us from sending media (specifically images) along with text messages to the Gemini 1.5 model.
2. It is affecting the functionality needed for applications involving image and text-based conversation flows.

[ankrgyl]

Looks like you might be missing an array around the second content block, i.e.

    { role: "user", content: { type: "image_url", image_url: { url: "https://example.com/image.jpg" } } }

should be

    { role: "user", content: [{ type: "image_url", image_url: { url: "https://example.com/image.jpg" } }] }

[nimish-gupta]

Looks like you might be missing an array around the second content block, i.e.

    { role: "user", content: { type: "image_url", image_url: { url: "https://example.com/image.jpg" } } }

should be

    { role: "user", content: [{ type: "image_url", image_url: { url: "https://example.com/image.jpg" } }] }

my bad in the issue description (updated the description), I am sending the array.

[ankrgyl]

Can you send an exact repro then? I just tried using the above, and it worked just fine:

In [18]: client = OpenAI(base_url='https://api.braintrust.dev/v1/proxy', api_key=os.environ['BRAINTRUST_API_KEY'])

In [19]: client.chat.completions.create(  model="gemini-1.5-flash-latest",
    ...:   messages=[
    ...:     { "role": "user", "content": "What do you think of this image?" },
    ...:     { "role": "user", "content": [{ "type": "image_url", "image_url": {"url": "https://cdn.prod.website-files.com/64949e4863d96e26a1da8386/64f5f56c78d05cf501922f99_64a2ef9774661044d9755e98_URL%2520-%2520Glossary.png" }}] }
    ...:   ],
    ...: )

Returned

Out[19]: ChatCompletion(id='dbc961c9-b492-4cda-beb1-630ac1b94a4c', choices=[Choice(finish_reason='stop', index=0, logprobs=None, message=ChatCompletionMessage(content='The image is a good visual representation of the different parts of a URL. It clearly labels the protocol, domain name, and extension, making it easy to understand how they work together. The example URL is also relevant and helpful. Overall, it is a simple and effective way to illustrate the concept of URLs.\n\nOne suggestion for improvement could be to use a more visually appealing font or color scheme.', refusal=None, role='assistant', function_call=None, tool_calls=None))], created=1729060733, model='gemini-1.5-flash-latest', object='chat.completion', service_tier=None, system_fingerprint=None, usage=CompletionUsage(completion_tokens=80, prompt_tokens=268, total_tokens=348))

[nimish-gupta]

So this is the code that i am using. I am this open ai node package

  const messages = [ {
    role: "user" as const,
    content: [
      {
        type: "image_url" as const,
        image_url: {
          url: "https://cdn.prod.website-files.com/64949e4863d96e26a1da8386/64f5f56c78d05cf501922f99_64a2ef9774661044d9755e98_URL%2520-%2520Glossary.png",
        },
      },
    ],
  }];

  const completion = await client.chat.completions.create({
    model: "gemini-1.5-flash-latest",
    messages,
    logprobs: true,
    temperature: 0,
  });

  console.log(completion);

After this i am getting the error:

[2024-10-16 12:20:39] ERROR: Unhandled rejection
    err: {
      "type": "BadRequestError",
      "message": "400 Invalid JSON payload received. Unknown name \"text\" at 'contents[0].parts[0]': Proto field is not repeating, cannot start list.",
      "stack":
          Error: 400 Invalid JSON payload received. Unknown name "text" at 'contents[0].parts[0]': Proto field is not repeating, cannot start list.
              at Function.generate (~/node_modules/.pnpm/openai@4.55.4_zod@3.23.8/node_modules/openai/error.js:45:20)
              at OpenAI.makeStatusError (~/node_modules/.pnpm/openai@4.55.4_zod@3.23.8/node_modules/openai/core.js:275:33)
              at OpenAI.makeRequest (~/node_modules/.pnpm/openai@4.55.4_zod@3.23.8/node_modules/openai/core.js:318:30)
              at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
      "status": 400,
      "headers": {
        "connection": "keep-alive",
        "content-type": "application/json; charset=UTF-8",
        "date": "Wed, 16 Oct 2024 06:50:39 GMT",
        "server-timing": "gfet4t7; dur=59",
        "transfer-encoding": "chunked",
        "x-amz-cf-pop": "DEL54-P6",
        "x-amzn-requestid": "b5178772-ad22-4a3d-9379-a2d100e263f0",
        "x-amzn-trace-id": "Root=1-670f623e-7aacdbad3c9efa58021df12b;Parent=63eae876af5b71e1;Sampled=0;Lineage=1:a00f27e0:0",
        "x-bt-cached": "MISS",
        "x-cache": "Error from cloudfront",
        "x-cached": "false",
        "x-content-type-options": "nosniff",
        "x-frame-options": "SAMEORIGIN",
        "x-xss-protection": "0"
      },
      "error": {
        "type": "Object",
        "message": "Invalid JSON payload received. Unknown name \"text\" at 'contents[0].parts[0]': Proto field is not repeating, cannot start list.",
        "stack":

        "code": 400,
        "status": "INVALID_ARGUMENT",
        "details": [
          {
            "@type": "type.googleapis.com/google.rpc.BadRequest",
            "fieldViolations": [
              {
                "field": "contents[0].parts[0]",
                "description": "Invalid JSON payload received. Unknown name \"text\" at 'contents[0].parts[0]': Proto field is not repeating, cannot start list."
              }
            ]
          }
        ]
      },
      "code": 400
    }

[ankrgyl]

Hmm it's unfortunately not reproducing for me. Do you have a support agent on the Google side? It may require their help (e.g. maybe your API key is going to a different model than mine):

In [7]: client.chat.completions.create(  model="gemini-1.5-flash-latest",
   ...:   messages=[
   ...:
   ...:     { "role": "user", "content": [{ "type": "image_url", "image_url": {"url": "https://cdn.prod.website-files.com/64949e4863d96e26a1da8386/64f5f56c78d05cf501922f99_64a2ef9774661044d9755e98_URL%2520-%2520Glossary.png" }}] }
   ...:   ],
   ...:   logprobs=True,
   ...:   temperature=0,
   ...: )
Out[7]: ChatCompletion(id='b48b36b2-2a30-420f-80a6-97d00bc44c6f', choices=[Choice(finish_reason='stop', index=0, logprobs=None, message=ChatCompletionMessage(content='Protocol: **http://**\nDomain name: **www.example.com**\nExtension: **blog/what-is-a-url**', refusal=None, role='assistant', function_call=None, tool_calls=None))], created=1729061879, model='gemini-1.5-flash-latest', object='chat.completion', service_tier=None, system_fingerprint=None, usage=CompletionUsage(completion_tokens=31, prompt_tokens=259, total_tokens=290))

[nimish-gupta]

e.g. maybe your API key is going to a different model than mine

Thanks for pointing out to this. I changed to gemini-1.5-flash and it starts working.

[ankrgyl]

Chatted a bit with the gemini team, and they suggest using gemini-1.5-pro and gemini-1.5-flash without the -latest suffix.