# "Could not parse JSON body" error in following Structured Output example

**URL:** <https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260>\
**Category:** API\
**Tags:** structured-output\
**Created:** [November 4, 2024, 2:49am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260 "2024-11-04T02:49:08Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![lopsided](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/lopsided/32/448631_2.png) [@lopsided](https://community.openai.com/u/lopsided)\
**Post date:** [November 4, 2024, 2:49am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/1 "2024-11-04T02:49:08Z")

</div>

Here is the code for the example, straight from [https://platform.openai.com/docs/guides/structured-outputs?context=with\_parse](https://platform.openai.com/docs/guides/structured-outputs?context=with_parse)

```auto
    from pydantic import BaseModel
    model = 'gpt-4o-2024-08-06'

    class CalendarEvent(BaseModel):
        name: str
        date: str
        participants: List[str]

    completion = client.beta.chat.completions.parse(
        model=model,
        messages=[
            {"role": "system", "content": "Extract the event information."},
            {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
        ],
        response_format=CalendarEvent
    )
    print(json.dumps(completion, indent=2))

```

Results in the following error:

```auto
openai.BadRequestError: Error code: 400 - {'error': {'message': "We could not parse the JSON body of your request. (HINT: This likely means you aren't using your HTTP library correctly. The OpenAI API expects a JSON payload, but what was sent was not valid JSON. If you have trouble figuring out how to fix this, please contact us through our help center at help.openai.com.)", 'type': 'invalid_request_error', 'param': None, 'code': None}}

```

---

<div class="post-metadata">

**Author:** ![\_j](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/_j/32/766292_2.png) [@\_j](https://community.openai.com/u/_j)\
**Post date:** [November 4, 2024, 3:47am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/2 "2024-11-04T03:47:32Z")

</div>

There is unseen code, obviously.

Let me show you how to make a request and receive the data.

Prepare - create a client instance:

```auto
from openai import Client
client = Client()

```

Throw in some code for printing arbitrary Python nested objects

```auto
def print_nested_dict(d: dict, indent: int = 0) -> None:
    """Recursively prints dictionary keys and values, handling nested dictionaries and lists."""
    for key, value in d.items():
        prefix = ' ' * indent
        if value is None:
            continue # Skip None values
        if isinstance(value, dict):
            print(f"{prefix}{key}:")
            print_nested_dict(value, indent + 2)
        elif isinstance(value, list):
            print(f"{prefix}{key}:")
            print_list(value, indent + 2)
        else:
            print(f"{prefix}{key}: {value}")

def print_list(lst: list, indent: int) -> None:
    """Recursively prints items in a list, handling nested dictionaries and lists."""
    for i, item in enumerate(lst):
        prefix = ' ' * indent
        if item is None:
            continue # Skip None values
        if isinstance(item, dict):
            print(f"{prefix}{i}:")
            print_nested_dict(item, indent + 2)
        elif isinstance(item, list):
            print(f"{prefix}{i}:")
            print_list(item, indent + 2)
        else:
            print(f"{prefix}{i}: {item}")

```

Create your BaseModel class

```auto
from pydantic import BaseModel
model = 'gpt-4o-2024-08-06'

class CalendarEvent(BaseModel):
    name: str
    date: str
    participants: list[str] # lower-case: built in typing of Python 3.9+

```

Make your API request

```auto
completion = client.beta.chat.completions.parse(
    model=model,
    messages=[
        {"role": "system", "content": "Extract the event information."},
        {"role": "user", "content":
         "Alice and Bob are going to a science fair on Friday."
         },
    ],
    response_format=CalendarEvent
)

```

Now, what do you do with that? The response from the openai python library is NOT a json, it is a pydantic model of objects and models itself.

You can dump out the response like this:

`print("response dump: ", completion.model_dump() )`

And see your full response Python objects from JSON:

`response dump: {'id': 'chatcmpl-APi..', 'choices': [{'finish_reason': 'stop', 'index': 0, 'logprobs': None, 'message': {'content': '{"name":"Science Fair","date":"Friday","participants":["Alice","Bob"]}', 'refusal': None, 'role': 'assistant', 'audio': None, 'function_call': None, 'tool_calls': [], 'parsed': {'name': 'Science Fair', 'date': 'Friday', 'participants': ['Alice', 'Bob']}}}], 'created': 1730691646, 'model': 'gpt-4o-2024-08-06', 'object': 'chat.completion', 'service_tier': None, 'system_fingerprint': 'fp_159d8341cc', 'usage': {'completion_tokens': 17, 'prompt_tokens': 92, 'total_tokens': 109, 'completion_tokens_details': {'audio_tokens': None, 'reasoning_tokens': 0}, 'prompt_tokens_details': {'audio_tokens': None, 'cached_tokens': 0}}} `

Or if only the assistant message is important to you, get that out:

`completion_message_dict = completion.choices[0].message.parsed.model_dump()`

And see what you have to work with then, again, not JSON string but Python:

`>>>print( completion_message_dict )`  
`{'name': 'Science Fair', 'date': 'Friday', 'participants': ['Alice', 'Bob']}`

That function you didn’t ask for? Let’s have it print

```python
>>>print_nested_dict(completion_message_dict)
name: Science Fair
date: Friday
participants:
  0: Alice
  1: Bob

```

So I’ve demonstrated making the call without error and making its response useful.

Code solution:

```auto
import json # if you still need it
from typing import List # for other types, like Optional, for Pydantic) 
from openai import Client
client = Client()

def print_nested_dict(d: dict, indent: int = 0) -> None:
    """Recursively prints dictionary keys and values, handling nested dictionaries and lists."""
    for key, value in d.items():
        prefix = ' ' * indent
        if value is None:
            continue # Skip None values
        if isinstance(value, dict):
            print(f"{prefix}{key}:")
            print_nested_dict(value, indent + 2)
        elif isinstance(value, list):
            print(f"{prefix}{key}:")
            print_list(value, indent + 2)
        else:
            print(f"{prefix}{key}: {value}")

def print_list(lst: list, indent: int) -> None:
    """Recursively prints items in a list, handling nested dictionaries and lists."""
    for i, item in enumerate(lst):
        prefix = ' ' * indent
        if item is None:
            continue # Skip None values
        if isinstance(item, dict):
            print(f"{prefix}{i}:")
            print_nested_dict(item, indent + 2)
        elif isinstance(item, list):
            print(f"{prefix}{i}:")
            print_list(item, indent + 2)
        else:
            print(f"{prefix}{i}: {item}")

from pydantic import BaseModel
model = 'gpt-4o-2024-08-06'

class CalendarEvent(BaseModel):
    name: str
    date: str
    participants: list[str] # lower-case: built in typing of Python 3.9+

completion = client.beta.chat.completions.parse(
    model=model,
    messages=[
        {"role": "system", "content": "Extract the event information."},
        {"role": "user", "content":
         "Alice and Bob are going to a science fair on Friday."
         },
    ],
    response_format=CalendarEvent
)
print("response dump: ", completion.model_dump(), "\n----\n" )
completion_message_dict = completion.choices[0].message.parsed.model_dump()
print("response: ", completion_message_dict, "\n----\n" )
print_nested_dict(completion_message_dict)

```

---

<div class="post-metadata">

**Author:** ![lopsided](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/lopsided/32/448631_2.png) [@lopsided](https://community.openai.com/u/lopsided)\
**Post date:** [November 4, 2024, 5:27am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/3 "2024-11-04T05:27:45Z")

</div>

I had been using “List” from “typing” module as follows:

```auto
from typing import List

```

Maybe that was the issue. Let me try this new code and get back to you. Thanks for your help.

---

<div class="post-metadata">

**Author:** ![lopsided](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/lopsided/32/448631_2.png) [@lopsided](https://community.openai.com/u/lopsided)\
**Post date:** [November 4, 2024, 6:50am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/4 "2024-11-04T06:50:55Z")

</div>

The code you showed is not working. Something wrong with my environment. I am using python 3.12 on Ubuntu 24.04 and OpenAI version is 1.53.

The following does not work. Note, since I am using python 3.12, I got rid of “List” from “typing” and using “list”.

```python
        class CalendarEvent(BaseModel):
            name: str
            date: str
            participants: list[str]
        client = OpenAI()
        completion = client.beta.chat.completions.parse(
            model=model,
            messages=[
                {"role": "system", "content": "Extract the event information."},
                {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
            ],
            response_format=CalendarEvent
        )
        print(completion.model_dump())

```

I get the following error:

```auto
openai.BadRequestError: Error code: 400 - {'error': {'message': "We could not parse the JSON body of your request. (HINT: This likely means you aren't using your HTTP library correctly. The OpenAI API expects a JSON payload, but what was sent was not valid JSON. If you have trouble figuring out how to fix this, please contact us through our help center at help.openai.com.)", 'type': 'invalid_request_error', 'param': None, 'code': None}}

```

However, using the `requests` module with the same `CalendarEvent` class works. Note that instead of passing a `BaseModel` subclass, I am extracting the json schema from it and using that.

```python
        class CalendarEvent(BaseModel):
            name: str
            date: str
            participants: list[str]
        resp = requests.post('https://api.openai.com/v1/chat/completions', headers={
            "Authorization": f'Bearer {APPENV["OPENAI_API_KEY"]}'
        }, json={
            "model": "gpt-4o-2024-08-06",
            "messages": [
                {
                    "role": "system",
                    "content": "Extract the event information."
                },
                {
                    "role": "user",
                    "content": "Alice and Bob are going to a science fair on Friday."
                }
            ],
            "response_format": {
                "type": "json_schema",
                "json_schema": {
                    "name": "whatever-man",
                    "schema": CalendarEvent.model_json_schema()   
                }
            }
        })
        print(resp.json())

```

Any ideas? Also, what is your environment? (Python version, OS version and OpenAI version).

---

<div class="post-metadata">

**Author:** ![\_j](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/_j/32/766292_2.png) [@\_j](https://community.openai.com/u/_j)\
**Post date:** [November 4, 2024, 7:57am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/5 "2024-11-04T07:57:01Z")

</div>

Here’s an answer for you: not the latest versions of support libraries like Pydantic.

You may need to make a venv and follow the install versioning I note here:

> [@What's wrong with my Structured Output response format?](https://community.openai.com/t/whats-wrong-with-my-structured-output-response-format/986003/3):
>
> Run this in your Python environment: import pydantic\_core, pydantic print(pydantic\_core.\_\_version\_\_, pydantic.\_\_version\_\_) Output result meeting the latest supported: 2.20.1 2.8.2 If you have lesser or greater versions in your Python 3.9-3.11 environment for OpenAI API requests, try this forced upgrade line from the user account (with access to upgrade those installations) or on the venv: pip install --upgrade --upgrade-strategy eager regex "charset-normalizer\<4" "idna" "urllib3\<3" "certi…

Problems - and using bleeding-edige python versions.

---

<div class="post-metadata">

**Author:** ![lopsided](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/lopsided/32/448631_2.png) [@lopsided](https://community.openai.com/u/lopsided)\
**Post date:** [November 4, 2024, 10:19am UTC](https://community.openai.com/t/could-not-parse-json-body-error-in-following-structured-output-example/1003260/6 "2024-11-04T10:19:03Z")

</div>

Yeah, bleeding edge is not a good idea. I only installed python 3.12 after I had errors with python 3.8 earlier. Apparently that did not resolve my issues. So I am now back on 3.8. But let me now try with python 3.11.

Thanks for your help!