Only supporting "max" reasoning is weird, their parameters are quite inflexible atm:

    Important limits:

    reasoning_effort currently supports only max; K3 always has thinking mode enabled.

    max_completion_tokens defaults to 131072 and can be set up to 1048576.

    temperature=1.0, top_p=0.95, n=1, presence_penalty=0, and frequency_penalty=0 are fixed; omit them from requests.

    Return the complete assistant message unchanged in multi-turn conversations and tool calls.

    Vision input does not support public image URLs. Use base64 or ms://<file-id>, and make content an array of objects.

    Web search is being updated and is not recommended for production workflows in the near term.