Gemini 3.1 Pro: Tune Reasoning, Vision and Cost in Python

Gemini 3.1 Pro Preview is the model everyone is wiring into their stacks this week. The Apple keynote on June 8 put a Gemini model inside Siri, Microsoft shipped a wave of its own MAI models the same day, and across developer communities the question that keeps coming up is not how smart is it but how do I stop it from being slow and expensive. The good news: Gemini 3 added three concrete knobs that let you trade reasoning depth, vision fidelity, and latency against cost on a per-request basis.