Using response_format in chat completion throws error

API
, ,
1

Do this:

import os
from openai import OpenAI
from openai.types.chat.completion_create_params import ResponseFormat

client = OpenAI(api_key=os.environ("OPENAI_API_KEY"))
response_format = ResponseFormat(type="json_object")

response = client.chat.completions.create(
    model="gpt-4-vision-preview",
    response_format=response_format,
    messages=[
        {
            "role": "system",
            "content": "You model sentences as arrays of JSON nodes and edges." 
        },
        {
            "role": "user",
            "content": "Sentence: ..."
        }
    ],
    max_tokens=300,
)

You get this error:

BadRequestError: Error code: 400 - {'error': {'message': '1 validation error for Request\nbody -> response_format\n  extra fields not permitted (type=value_error.extra)', 'type': 'invalid_request_error', 'param': None, 'code': None}}

I tried using requests and calling the endpoint directly, not via the Python library, and got the same error.

1 Like
2

Use

response_format={"type": "json_object"},

in the completions create

3

Thanks, but that throws the same error. Itā€™s the reason I went down the path of trying response_format = ResponseFormat(type="json_object").

The issue seems to be that response_format isnā€™t recognized. Itā€™s getting invalidated as an extra, unexpected field.

4

Okay, USER ERROR!

I was using the wrong model :frowning:

This works: gpt-4-1106-preview.

This doesnā€™t: gpt-4-vision-preview.

So, note that you canā€™t get JSON output with the vision model, at least with the current preview.

2 Likes
5

Hello, Iā€™m looking for a response_format doing this:

response_format: { type: ā€˜json_listā€™ },

Any ideas on how to do it? The purpose is to return list with consistently valid JSON format to be parsed after, for now Iā€™m just adding tokens in the prompt to achieve this result.

6

Iā€™m not aware that ā€œjson_listā€ is a valid response format.

I think if you want to do what youā€™re asking, youā€™ll need to try one of these approaches:

  • Use json_object and prompt for an array in the result. For example, include something like, ā€œReturn a list of Xā€ in your prompt. Then you should get an array object in your JSON.
  • Use function call. This will give you more control. You can define JSON Schema that specifies an array attribute to guarantee getting back an array.
1 Like
7

thanks, implicite description of the expected result in the system and user prompt still seems to be an ideal solution at the moment, without the use of the json_object param.