Gemini 3.1 Pro Preview (Vertex AI)

Gemini 3.1 Pro Preview is a Google-developed reasoning system positioned for demanding software engineering and agentic tasks, with third-party tooling describing it as a frontier reasoning model that delivers enhanced coding performance, improved agentic reliability, and more efficient token usage across complex workflows. The model is built on a multimodal foundation and is documented on Google's official Gemini API developer site, reflecting its role as a reasoning-focused variant in the Gemini Pro lineage rather than a lightweight chat model.

In practical coding-agent evaluations, Gemini 3.1 Pro Preview has been benchmarked on the PinchBench real-world OpenClaw agent suite, where it posted an average score of 76.6 percent across 28 of 50 official models and earned a Kilo rank of 78 among available coding models. These results suggest the variant is well suited to multi-step agent execution, tool use, and recovery scenarios, making it a natural fit for developer-assistant and code-generation pipelines that need sustained reasoning over long, tool-augmented sessions.