GPT5 Models | Tool choices other than 'auto' are not supported with model

Confirm this is an issue with the Python library and not an underlying OpenAI API

• This is an issue with the Python library

Describe the bug

We are unable to use any tool_choice besides 'auto' for GPT5 models in the Responses API using the latest release v.1.99.5.

Documentation:

• https://platform.openai.com/docs/guides/latest-model#allowed-tools
• https://platform.openai.com/docs/api-reference/responses/create#responses_create-tool_choice

BadRequestError: Error code: 400 - {'error': {'message': "Tool choices other than 'auto' are not supported with model 'gpt-5-mini-2025-08-07' and the following tool types: 'code_interpreter', 'file_search'.", 'type': 'invalid_request_error', 'param': 'tool_choice', 'code': None}}

Posts on community.openai.com:

• https://community.openai.com/t/error-400-tool-choices-other-than-auto-are-not-supported-with-model-gpt-5-and-the-following-tool-types-web-search-preview/1337152
• https://community.openai.com/t/gpt5-and-forced-web-search/1344079
• https://community.openai.com/t/gpt5-cannot-use-web-search-please-help/1337041

To Reproduce

stream = await llm.responses.create(
    model="gpt-5",
    input="Use your python tool to do this math: 8*9183*7663",
    tools=[
        {"type": "code_interpreter", "container": {"type": "auto"}},
    ],
    tool_choice={
        "type": "allowed_tools",
        "mode": "auto",
        "tools": [
            {
                "type": "code_interpreter",
            }
        ],
    },
    stream=True,
)
async for event in stream:
    print(event.model_dump_json(indent=2))

Code snippets

OS

Windows 11

Python version

Python 3.13.2

Library version

openai v.1.99.5

Start with the Responses API call in the reproduction and compare its allowed_tools tool_choice with the linked API documentation. Check whether the 400 response is caused by the Python library or the underlying API; done means the supported behavior and any required library change are established.