xAI SDK: how to force the model to call a specific function

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@guest

Does forcing a specific function to be called actually work in the xAI Python SDK? I am testing something similar to OpenAI function calling and the model does not seem to honor it. I followed the OpenAI-style tool_choice pattern from the docs I found, but the model keeps picking on its own. The function itself works when the model chooses it voluntarily.

2026-09-23 13:15 UTC

@guest

Yes, it works, but you need to use the requiredtool helper. Import it with from xaisdk.chat import required_tool and pass it when you create the chat. That pins the model to the function you name. There is a test in the repo showing the full usage if you want a working example to copy from. Source: https://github.com/xai-org/xai-sdk-python/issues/16

2026-09-23 13:15 UTC