>You cannot disable thinking for Gemini 3 Pro. Gemini 3 Flash also does not support full thinking-off, but the minimal setting means the model likely will not think (though it still potentially can). If you don't specify a thinking level, Gemini will use the Gemini 3 models' default dynamic thinking level, "high".

https://ai.google.dev/gemini-api/docs/thinking#levels

I was talking about Gemini 3 Flash, and you absolutely can disable reasoning, just try sending thinking budget: 0. It's strange that they don't want to mention this, but it works.